This specification is applicable to the geotechnical investigation of tunnels, stations, roadbeds, bridges, culverts, vehicle depots and ancillary buildings of subways and light rail transit. GB 50307-1999 Geotechnical Investigation Specification for Subway and Light Rail Transit GB50307-1999 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China Code on geotechnical investigations for metro and light rail transitGB50307—1999
Editing department: Office of Capital Planning and Construction CommitteeApproving department: Ministry of Construction of the People's Republic of ChinaEffective date: June 1, 2000
2—13-1
Notice on the promulgation of national standards
"Specifications for Geotechnical Investigation of Subway and Light Rail Transit" and "Specifications for Engineering Survey of Subway and Light Rail Transit"Construction Standards [1999] No. 318
According to the requirements of the "Notice on Issuing the Plan for the Formulation and Revision of Engineering Construction Standards in 1998 (Second Batch)" (Construction Standards [1998] No. 224) issued by our Ministry, the "Specifications for Geotechnical Investigation of Subway and Light Rail Transit" and "Specifications for Engineering Survey of Subway and Light Rail Transit" jointly formulated by the Office of Capital Planning and Construction Committee and relevant departments have been reviewed and approved as mandatory national standards by relevant departments, with the numbers: GB 50307—1999 and GB 50308—1999, from 2000 onwards
This specification is compiled in accordance with the requirements of the Ministry of Construction of the People's Republic of China, Document No. 224 of 1998, "Notice on Issuing the 1998 Engineering Construction Standards and Specifications Formulation and Revision Plan (Second Batch)".
This specification has 17 chapters, 11 appendices and clause explanations, and the main contents are:
, Principles and requirements for the arrangement of work at each survey stage. , Methods for determining technical parameters of geotechnical and groundwater. 3. Survey points for different construction methods. 4. Survey contents of special soils and elevated lines, bridges and culverts. 5. Preparation of survey reports and engineering monitoring. The unit authorized to be responsible for the specific interpretation of this specification is: Beijing Urban Construction Survey and Mapping Institute, address: No. 6, Section 5, Anhuili, Chaoyang District, Beijing, Postal Code: 100101, http://cki.com.cn, Email: [email protected]. It is hoped that all units will accumulate experience in use and send suggestions and opinions to Beijing Urban Construction Surveying and Mapping Institute for reference in future revisions. 2-13-2
Effective from June 1.
This specification is managed by the Office of the Capital Planning and Construction Committee, Beijing Urban Construction Surveying and Mapping Institute is responsible for specific interpretation, and the Standard and Norm Research Institute of the Ministry of Construction organizes China Planning Press to publish and distribute it. Ministry of Construction of the People's Republic of China
December 15, 1999
The main editor, participating editors and main drafters of this specification are as follows: Main editor: Beijing Urban Construction Survey and Mapping Institute Participating editors: Beijing Urban Construction Design Institute Guangzhou Metro Corporation
Shanghai Geotechnical Engineering Survey and Design Institute
Beijing Survey and Design Institute
Northwest Comprehensive Survey and Design Institute
Shenyang Survey and Mapping Institute
Qingdao Survey and Mapping Institute
Comprehensive Survey Research and Design Institute of the Ministry of Construction
Scientific Research Institute of the Ministry of Railways
Shenzhen Survey and Mapping Institute
Main drafters: Shuai Shaowu
Liu Gongxi Shi Cunlin
Wang Yuanxiang
Zhuang Baonao
Wu Chengxiao
Zhou Shijian|| tt||Yi Guorong
Fei Xinyuan
Han Shijian
Chen Yumei
Lin Zaiguan
Zhang Nairui
Luo Meiyun
Gu Baohe
Fu Touxin
Peng Jiajun
Terms and Symbols
Terms·
Basic Provisions
Numbering, Description and Classification of Rock Soil and Surrounding Rock
Rock Rock classification
Soil classification·
Tunnel surrounding rock classification·
Soil and rock excavability classification·
Geotechnical description
5 Work content of the survey stage
General provisions
Feasibility study stage·
Preliminary survey stage·
5.4 Detailed survey stage·
5.5 Geotechnical engineering survey work during construction. 6
Engineering geological survey and mapping...
Exploration and sampling
-General provisions·
..2 Drilling
7.3 Well exploration and trench exploration
7.4 Sampling
7.5 Geophysical exploration
8 Groundwater
--General provisions
8.2 Investigation and evaluation
8.3 Determination of groundwater parameters
8.4 Collection of water samples and test items
Engineering precipitation
9 In-situ test
General provisions
Standard penetration test
Dynamic penetration test
++++++
Side pressure test
Static penetration test
Load test
Cross plate shear Test
Wave speed test
Guodian Electric
—13-5
13—5
13—5
13—5
-13—5
2—13—6|| tt||213—6
2—13-7
2—13—7
2—13-7
2—13—7
-13—8
2—13—8
.. 2-138
... 2-13-9
: 2-13--9
2—13—9
2—13--9
.. 2—13--10
2-13—10
-13--10
2--13-10
2-13-10
, 2-13-10
2-13-10
: 2-13-11
. 2-13—11
2—13—12
..2—13--12
2--13--12
...2—13—12
2—13—12
2—13—13
2—13—13
2—13—13
Geotechnical tests
General provisions
Conventional tests on soil||tt| |Bed coefficient
Thermophysical index
Soil dynamic property test.
Rock right test·
Special soil investigation
Collapsible soil
Expanding soil
Weathered rock and residual soil
Open cut investigation
General provisions·
Slope excavation…
Support excavation·
Cover excavation
Blind excavation investigation
General provisions·
Mining method.
13.3 Shield method…．
2—13—14
-13--14
-13—14
-13--14
.... 2--13-14
13—14
-13---14
. 213--14
13—14
13—15
-13—16
-13—17
-13-17
2—13-17
. 2—13-17
2-—13--18
—13-18
..... 2-13--18
2—13—18
......... 2-1319
Survey of geotechnical reinforcement engineering
+..+++...... 213-19
General provisions·
14.2 Rock reinforcement·
14..3 Soil reinforcement.
.. 2--13-19
.. 2--13---20
2—13—20
Survey of roadbed, elevated lines and bridges and culverts2-13—2015
General provisions·
Survey of roadbed
15.3Survey of elevated lines·
15.4Survey of bridges and culverts·
.... 2—1320
.·*. 2—13-20
2-13—21
....2—13—21
Results analysis and investigation report
+ .............. 213-22
-General provisions
Parameter determination·
Basic requirements for investigation report
: 2—-13—22
2—13—-22
2—13—22
. 213--23
16.4Contents of investigation report
Engineering monitoring
General provisions·
17.2Pre-construction monitoring
.... 2--13-23
2—13—23
2—13--23
2-13—3
Monitoring during construction·
Monitoring after construction
Appendix A
2--13--24
..... 2-13-24
Classification of rocks according to weathering degree·-13—25
Classification of soil and rock digging properties·
Appendix H
*.*. 2-13-25
Principles,
Appendix C
Characteristics and application scope of geophysical exploration methods
Appendix D
Appendix E
Appendix F
Calculation of permeability coefficient
.... 2-13-26
2—13—27
Additional ground settlement caused by precipitation
-13—27
Empirical value of base coefficient K
.. 2—13--27
2—13—4
Appendix G Geotechnical thermophysical indicators
Appendix H Loess classification by engineering geological analogy method...
Appendix
Granite residual soil fine
grained soil test...．
Appendix K
Appendix L
Applicability of soil reinforcement methods
Commonly used legends
Explanation of terms used in this code
, 2—13--28
2—13—28
2—1329
2—[3—29
2~-13—30
213—30
This code is formulated to unify the technical standards for geotechnical engineering investigation for subway and light rail transportation and to ensure quality, safety, applicability, advanced technology and economic rationality. 1.0.2 This specification applies to the geotechnical investigation of tunnels, stations, roadbeds, bridges, culverts, vehicle depots and ancillary buildings of subways and light rail transit. 1.0.3 In the geotechnical investigation of subways and light rail transit, attention should be paid to environmental protection to prevent or reduce the damage to the environmental balance. And the hazards to the safety of municipal engineering should be predicted and controlled.
1. 0.4 The geotechnical investigation of subways and light rail transit must widely collect existing investigation, design and construction data, arrange the workload and test methods according to different construction plans and construction impact ranges, provide investigation data, and put forward engineering suggestions. 1.0.5 The investigation stage should be compatible with the design stage. It can be divided into the feasibility study investigation stage, the preliminary investigation stage, and the detailed investigation stage. In geologically complex areas, the geotechnical investigation during construction can be carried out in conjunction with the construction stage.
1.0.6 In addition to implementing this specification, the geotechnical investigation of subways and light rail transit should comply with the provisions of the relevant mandatory standards currently in force in the country. Terms and symbols
2.1.1 Underground railway netro or underground railway or subway tube A high-speed, large-capacity railway system built in a city, hauled by electric locomotives, with a long-term one-way peak hourly passenger flow exceeding 30,000 passengers. The line is usually located in an underground tunnel. Sometimes it is extended from underground to the ground, or is located on a viaduct. 2.1.2 Light rail transit A ​​high-speed, medium-capacity rail transit passenger transportation system built in a city, with a long-term one-way peak hourly passenger flow between 10,000 and 30,000 passengers. The line is located on the ground, on a viaduct or underground.
2.1.3 Engineering environment
engineering environment
The engineering environment refers to the natural environment and cultural environment in which the project is located, as well as the new environment created by the construction of the project. Study the mutual influence and mutual restriction between environment and engineering construction, and make engineering construction and environmental improvement proceed synchronously through investigation, prediction and evaluation, so as to achieve the goal of sustainable development of engineering construction. 2.1.4 Surrounding rock
refers to the rock and soil within a certain range around the tunnel that affects its stability. 2.1.5 Coefficient of subgrade reaction The subgrade coefficient is the pressure required for the foundation soil to produce unit displacement under the action of external force, also known as elastic resistance coefficient or foundation reaction coefficient. There are horizontal subgrade coefficient and vertical subgrade coefficient.
Thermophysical index Thermophysical index of rock and soil mainly includes thermal conductivity, thermal conductivity and specific heat capacity. 2.2 Symbol
-Compression coefficient
~Width of foundation bottom
—-Adhesion
Compression index
—-Rebound index
dSoil particle size
dl. -—--Effective particle size
Median particle size
Relative density
Elastic modulus
Rebound modulus
Dynamic elastic modulus
Deformation modulus
Compression modulus
Porosity ratio
—Basic value of foundation bearing capacity
Standard value of foundation bearing capacity
Saturated uniaxial compressive strength of rock
Foundation Shear modulus; specific gravity of soil
dynamic shear modulus
liquidity index of soil
plasticity index of soil
static earth pressure coefficient
active earth pressure coefficient
passive earth pressure coefficient
sea permeability coefficient of soil
bed coefficient
number of hammer blows for standard penetration test
number of hammer blows for light dynamic penetration test
heavy Dynamic penetration test hits
Super heavy dynamic penetration test hits
Overconsolidation ratio
Total pressure
Pre-consolidation pressure
-Water yield
Static penetration test head resistance
Standard value of soil bearing force at pile end
Standard value of soil friction force around pile
Unconfined compressive strength
Settlement plate
Soil saturation|| tt||Soil sensitivity
Groundwater velocity
Soil compression wave velocity
Soil shear wave velocity
Soil natural water content
—Liquid limit
Soil gravity density (weight)
Dry weight of soil
Poisson's ratio
Soil density
Internal reservoir carrying angle
3 Basic provisions
3. 0.1 Geotechnical engineering investigation of subway and light rail transit should be carried out according to the accuracy requirements of different design stages. 3. 0. 2 Geotechnical engineering investigation of subway and light rail transit should be combined with different construction methods to propose evaluation of geotechnical distribution and its technical parameters for engineering design, and engineering suggestions and monitoring measures should be proposed.
3.0.3 The safety level of the project should be determined according to the consequences of project damage and the type of project. The safety level can be determined according to Table 3.0.3:
Main 3.0.3 Project Safety Level
Consequences of damage
Severeest
Minorest
Type of project
Health roads and exits, viaducts, large and medium bridges, more than 30 floors, high-rise buildings and other important structures
Structural foundation, maintenance depot, cattle parking depot
Secondary flow
3.0.4 The thermal physical indicators of rock and soil should be measured for tunnel ventilation design or freezing method construction. 3.0.5 The water condition information of the surface water system should be collected and analyzed, and the groundwater parameters along the line should be provided.
3.0.6 For construction sites where the groundwater level is artificially lowered, monitoring measures should be proposed for deformation of nearby soil bodies and settlement of important buildings. 3.0.7 Important natural and cultural landscapes along the route should be investigated, and protective measures should be proposed.
3.0.8 Dangerous areas such as underground harmful and flammable gases, water inrush, and sand inrush should be investigated, and necessary surveys and tests should be carried out. 3.0.9 The complexity of the sites for subway and light rail transportation should be divided according to Table 3.0.9: Table 3.0.9. Site complexity
Radial landform transformation
Flat opening
Single site
Medium complex
Miscellaneous site
Complex site
Gentle slope
Basically flat
tProcess state
The stratum is relatively stable, if the property does not change much, the groundwater level is relatively high. It is generally composed of hard soil or medium soil. The stratum changes greatly, if the property is changeable, the groundwater level is relatively high. Generally, slopes are mostly composed of medium hard soil and medium soil. The site has a large height difference and the upper surface is complex. The upper surface is soft, the rise is large, and the groundwater level is high. It contains many types of groundwater.
3. 0. 10 Subway and light rail transportation should be defended according to the local basic intensity. 3.0.11 Classification of site soil types, classification of construction site categories, and identification of foundation soil liquefaction. Subway and light rail transit engineering structures shall comply with the relevant provisions of the current national standard "Code for Seismic Design of Railway Engineering XGBI111". For ground buildings, the current national standard "Code for Seismic Design of Buildings XGBJ11" shall be implemented. The depth of the division shall meet the design needs.
3.0.12 The survey of the depot and its ancillary buildings can be carried out simultaneously with the mainline survey. The survey of ventilation ducts, ventilation shafts and water sources should be carried out during the detailed survey stage. 3.0.13 Monitoring suggestions should be made for the deformation and stress changes of rock mass, the stability of dense rock, the effect of precipitation, the state of the supporting structure, and the impact on adjacent buildings and municipal facilities. Geotechnical naming, description and surrounding rock classification
4.1 Rock classification
4.1.1 Rocks should be divided into igneous rocks, sedimentary rocks and metamorphic rocks according to their genesis. 4.1.2 Rocks shall be classified according to the saturated ultimate compressive strength F, as shown in Table 4.1.2. Table 4.1.2 Classification of rock (MPa)
Sub-rock category
Physical quality rock
Rock quality
Hard rock
Soft rock
Ultra-weathered
4.1.3 The weathering degree of rock shall be classified into unweathered, slightly weathered, moderately weathered, strongly weathered and fully weathered according to Appendix A of this Code.
4.1.4 According to the softening coefficient K, it shall be classified into softened rock K, ≤ 0.75 and non-softened rock K, > 0.75.
Note, K, is the ratio of the rock monosaccharide extreme compressive strength in the saturated state to that in the air-dried state. 4.2 Classification of soils
4.2.1 According to the age of deposition, soils are divided into old sedimentary soils, general sedimentary soils, and recent sedimentary soils, and should meet the following requirements:
Old sedimentary soils: soil layers deposited in the late Pleistocene of the Quaternary Period (before the cultural period). 1
2 General sedimentary soils: soil layers deposited in the Holocene of the Quaternary Period (before the cultural period). Recent sedimentary soils: soil layers deposited recently since the cultural period. 4.2.2 According to geological origin, soils should be divided into residual soils, colliery soils, alluvial soils, alluvial soils, silt soils, glacial soils, and aeolian soils.
4.21.3 According to the organic matter content W. in the soil, soils can be divided into inorganic soils, organic soils, carbonaceous soils, and peat (organic matter content W. is the ignition loss at 550C). Determined according to Table 4.2.3. Table 4.2.3 Classification by organic content (W.) (%) Name
Inorganic soil
Organic soilbZxz.net
Muddy soil
Organic matter content
SAWA10
10<≤60
Classification of soil According to particle gradation, it should be divided into crushed stone soil and sandy soil and should meet the following requirements 4.2.4
Crushed stone soil: soil in which the mass of particles with a particle size greater than 2 mm exceeds 50% of the total mass.
Sand soil: soil with a particle size greater than 2 mm and a mass of particles greater than 0.075 mm exceeding 50% of the total mass. 3 The classification of gravel soil and sand soil should be determined according to Table 4.2.4-1 and Table 4.2, 4-2: Table 4.2.4-1 Classification of gravel soil
Soil name
Number Shape
Circular Sub-circular as the standard
Mainly shaped
Mainly graphic and sub-circular
Angular as the standard
Mainly shaped and sub-shaped
Mainly angular
Number of particles
Mainly shaped and sub-shaped
Mainly angular
Mainly shaped
Number of particles
Mainly shaped and sub-shaped
Mainly angular
Mainly shaped
Mainly shaped
Number of particles
Mainly shaped with a particle size greater than 200 mm exceeding 50% of the total mass.Mainly shaped with a particle size greater than 20 mm exceeding 50% of the total mass.Mainly shaped with a particle size greater than 2 mm exceeding 50% of the total mass.Table 4. 2.4-2 Classification of sandy soil Name of sandy soil Powder content Particles with a diameter greater than 2 mm account for more than 25% of the total mass and less than 50% Particles with a diameter greater than 0.5 mm account for more than 50% of the total mass Particles with a diameter greater than 0.25 mm account for more than 50% of the total mass Particles with a diameter greater than 0.075 mm account for more than 50% of the total mass Particles with a diameter greater than 0.075 mm account for more than 50% of the total mass According to the plasticity index, it can be divided into silt and clay. 4.2.5 Silt: Soil with a plasticity index of 1, greater than 3 and less than or equal to 10 is clay; plasticity index I, greater than 10, is determined according to Table 4.2.5. 2
Table 4. 2. 5 Classification of clay soil
Name of soil
Silty clay
Organization index T.
10≤17
4.2.6 Special soil: According to its special properties, it is divided into collapsible soil, expansive soil, soft soil, residual soil and artificial fill
1 Collapsible soil: It is formed by accumulation in arid and semi-arid environments, with low consolidation degree and large pore age ratio. With the increase of water content or water loss, it will produce significant and large additional compression deformation, mainly loess and loess-like soil. But it also includes some gravel soil, sandy soil and mixed soil formed in similar environments. Collapsible soil is divided into self-weight collapsible soil and non-self-weight collapsible soil.
2 Expansive soil: It contains more or a large amount of hydrophilic clay minerals, and has significant water absorption expansion and water loss shrinkage and reciprocating reversible deformation characteristics. 3 Soft soil: clay soil with natural water content greater than or equal to liquid limit, natural porosity greater than or equal to 1.0, and gray or gray-black appearance, with technical characteristics such as high compressibility (a1-10.5MPa1), low strength (C<30kPa), high sensitivity and low permeability. Clay soil with natural water content greater than liquid limit, porosity greater than or equal to 1.5 and containing a large amount of organic matter is called silt; clay soil with natural porosity less than 1.5 but greater than or equal to 1.0 is called silty soil.
4 Residual soil: the organizational structure of the rock has been completely destroyed, and its mineral components have been completely weathered into soil but not transported except for quartz. Artificial fill: soil filled by human activities, according to its material composition and filling method, can be divided into the following three categories:
1) Plain fill: fill composed of one or more materials such as crushed stone, sand, silt, clay, etc., without impurities or with few impurities. According to the main components, plain fill can be divided into crushed stone plain fill, sandy plain fill, silt-quality fill and clay-quality fill, etc.
2) Miscellaneous fill: fill containing a large amount of construction waste, industrial waste or domestic waste, etc., can be divided into construction waste fill, industrial material fill and domestic waste fill according to the composition of the materials
3) Flushing fill: fill formed by hydraulically moving mud and sand, also known as blowing fill. 4.3 Classification of tunnel surrounding rock
4.3.1 Tunnel surrounding rock should be classified according to Table 4.3.1. Table 4.3.1 Classification of main engineering geological conditions: hard rock (saturated ultimate compressive strength, > soft surface (glass interlayer) type: membrane type; hard rock (F, ≥30MPa); affected by geological structure, structural characteristics and research: basket-shaped block structure (most interlayer) and through-stretch joints, but its occurrence and star-shaped block structure. The combination relationship will not cause sliding. The waist-shaped rock is a medium-sized body structure with few differences. It is a relatively high-quality rock (J, ~30MPa). It is slightly affected by the geological structure and has no joints. The layered rock is palm-shaped (>30MPa). It is affected by the geological structure and has developed soft waists (rate is 5MPa). However, its occurrence and superposition are not known. The layers are body layers or medium-sized layers. The valleys between waists may be soft rocks with relatively high quality (5MPa).0. 9. Site complexity
Radial landform
Opening flat
Balanced site
Medium complex
Miscellaneous site
Complex site
Gentle slope
Basically flat
tProcedure
The strata are relatively stable, if the properties do not change much, the groundwater level is relatively high. Generally, the strata are composed of hard soil or medium soil. The strata change greatly, if the properties are changeable, the groundwater level is relatively high. Generally, the slopes are composed of medium hard soil and medium soil. The site has a large height difference and the upper surface is complex. The upper surface is soft, the rise is large, the groundwater level is high, and it contains many types of groundwater
3. 0. 10 Subway and light rail transportation should be protected according to the local basic intensity. 3.0.11 Classification of site soil types, classification of construction site categories, and identification of foundation soil liquefaction. Subway and light rail transit engineering structures shall comply with the relevant provisions of the current national standard "Code for Seismic Design of Railway Engineering XGBI111". For ground buildings, the current national standard "Code for Seismic Design of Buildings XGBJ11" shall be implemented. The depth of the division shall meet the design needs.
3.0.12 The survey of the depot and its ancillary buildings can be carried out simultaneously with the mainline survey. The survey of ventilation ducts, ventilation shafts and water sources should be carried out during the detailed survey stage. 3.0.13 Monitoring suggestions should be made for the deformation and stress changes of rock mass, the stability of dense rock, the effect of precipitation, the state of the supporting structure, and the impact on adjacent buildings and municipal facilities. Geotechnical naming, description and surrounding rock classification
4.1 Rock classification
4.1.1 Rocks should be divided into igneous rocks, sedimentary rocks and metamorphic rocks according to their genesis. 4.1.2 Rocks shall be classified according to the saturated ultimate compressive strength F, as shown in Table 4.1.2. Table 4.1.2 Classification of rock (MPa)
Sub-rock category
Physical quality rock
Rock quality
Hard rock
Soft rock
Ultra-weathered
4.1.3 The weathering degree of rock shall be classified into unweathered, slightly weathered, moderately weathered, strongly weathered and fully weathered according to Appendix A of this Code.
4.1.4 According to the softening coefficient K, it shall be classified into softened rock K, ≤ 0.75 and non-softened rock K, > 0.75.
Note, K, is the ratio of the rock monosaccharide extreme compressive strength in the saturated state to that in the air-dried state. 4.2 Classification of soils
4.2.1 According to the age of deposition, soils are divided into old sedimentary soils, general sedimentary soils, and recent sedimentary soils, and should meet the following requirements:
Old sedimentary soils: soil layers deposited in the late Pleistocene of the Quaternary Period (before the cultural period). 1
2 General sedimentary soils: soil layers deposited in the Holocene of the Quaternary Period (before the cultural period). Recent sedimentary soils: soil layers deposited recently since the cultural period. 4.2.2 According to geological origin, soils should be divided into residual soils, colliery soils, alluvial soils, alluvial soils, silt soils, glacial soils, and aeolian soils.
4.21.3 According to the organic matter content W. in the soil, soils can be divided into inorganic soils, organic soils, carbonaceous soils, and peat (organic matter content W. is the ignition loss at 550C). Determined according to Table 4.2.3. Table 4.2.3 Classification by organic content (W.) (%) Name
Inorganic soil
Organic soil
Muddy soil
Organic matter content
SAWA10
10<≤60
Classification of soil According to particle gradation, it should be divided into crushed stone soil and sandy soil and should meet the following requirements 4.2.4
Crushed stone soil: soil in which the mass of particles with a particle size greater than 2 mm exceeds 50% of the total mass.
Sand soil: soil with a particle size greater than 2 mm and a mass of particles greater than 0.075 mm exceeding 50% of the total mass. 3 The classification of gravel soil and sand soil should be determined according to Table 4.2.4-1 and Table 4.2, 4-2: Table 4.2.4-1 Classification of gravel soil
Soil name
Number Shape
Circular Sub-circular as the standard
Mainly shaped
Mainly graphic and sub-circular
Angular as the standard
Mainly shaped and sub-shaped
Mainly angular
Number of particles
Mainly shaped and sub-shaped
Mainly angular
Mainly shaped
Number of particles
Mainly shaped and sub-shaped
Mainly angular
Mainly shaped
Mainly shaped
Number of particles
Mainly shaped with a particle size greater than 200 mm exceeding 50% of the total mass.Mainly shaped with a particle size greater than 20 mm exceeding 50% of the total mass.Mainly shaped with a particle size greater than 2 mm exceeding 50% of the total mass.Table 4. 2.4-2 Classification of sandy soil Name of sandy soil Powder content Particles with a diameter greater than 2 mm account for more than 25% of the total mass and less than 50% Particles with a diameter greater than 0.5 mm account for more than 50% of the total mass Particles with a diameter greater than 0.25 mm account for more than 50% of the total mass Particles with a diameter greater than 0.075 mm account for more than 50% of the total mass Particles with a diameter greater than 0.075 mm account for more than 50% of the total mass According to the plasticity index, it can be divided into silt and clay. 4.2.5 Silt: Soil with a plasticity index of 1, greater than 3 and less than or equal to 10 is clay; plasticity index I, greater than 10, is determined according to Table 4.2.5. 2
Table 4. 2. 5 Classification of clay soil
Name of soil
Silty clay
Organization index T.
10≤17
4.2.6 Special soil: According to its special properties, it is divided into collapsible soil, expansive soil, soft soil, residual soil and artificial fill
1 Collapsible soil: It is formed by accumulation in arid and semi-arid environments, with low consolidation degree and large pore age ratio. With the increase of water content or water loss, it will produce significant and large additional compression deformation, mainly loess and loess-like soil. But it also includes some gravel soil, sandy soil and mixed soil formed in similar environments. Collapsible soil is divided into self-weight collapsible soil and non-self-weight collapsible soil.
2 Expansive soil: It contains more or a large amount of hydrophilic clay minerals, and has significant water absorption expansion and water loss shrinkage and reciprocating reversible deformation characteristics. 3 Soft soil: clay soil with natural water content greater than or equal to liquid limit, natural porosity greater than or equal to 1.0, and gray or gray-black appearance, with technical characteristics such as high compressibility (a1-10.5MPa1), low strength (C<30kPa), high sensitivity and low permeability. Clay soil with natural water content greater than liquid limit, porosity greater than or equal to 1.5 and containing a large amount of organic matter is called silt; clay soil with natural porosity less than 1.5 but greater than or equal to 1.0 is called silty soil.
4 Residual soil: the organizational structure of the rock has been completely destroyed, and its mineral components have been completely weathered into soil but not transported except for quartz. Artificial fill: soil filled by human activities, according to its material composition and filling method, can be divided into the following three categories:
1) Plain fill: fill composed of one or more materials such as crushed stone, sand, silt, clay, etc., without impurities or with few impurities. According to the main components, plain fill can be divided into crushed stone plain fill, sandy plain fill, silt-quality fill and clay-quality fill, etc.
2) Miscellaneous fill: fill containing a large amount of construction waste, industrial waste or domestic waste, etc., can be divided into construction waste fill, industrial material fill and domestic waste fill according to the composition of the materials
3) Flushing fill: fill formed by hydraulically moving mud and sand, also known as blowing fill. 4.3 Classification of tunnel surrounding rock
4.3.1 Tunnel surrounding rock should be classified according to Table 4.3.1. Table 4.3.1 Classification of main engineering geological conditions: hard rock (saturated ultimate compressive strength, > soft surface (glass interlayer) type: membrane type; hard rock (F, ≥30MPa); affected by geological structure, structural characteristics and research: basket-shaped block structure (most interlayer) and through-stretch joints, but its occurrence and star-shaped block structure. The combination relationship will not cause sliding. The waist-shaped rock is a medium-sized body structure with few differences. It is a relatively high-quality rock (J, ~30MPa). It is slightly affected by the geological structure and has no joints. The layered rock is palm-shaped (>30MPa). It is affected by the geological structure and has developed soft waists (rate is 5MPa). However, its occurrence and superposition are not known. The layers are body layers or medium-sized layers. The valleys between waists may be soft rocks with relatively high quality (5MPa).0. 9. Site complexity
Radial landform
Opening flat
Balanced site
Medium complex
Miscellaneous site
Complex site
Gentle slope
Basically flat
tProcedure
The strata are relatively stable, if the properties do not change much, the groundwater level is relatively high. Generally, the strata are composed of hard soil or medium soil. The strata change greatly, if the properties are changeable, the groundwater level is relatively high. Generally, the slopes are composed of medium hard soil and medium soil. The site has a large height difference and the upper surface is complex. The upper surface is soft, the rise is large, the groundwater level is high, and it contains many types of groundwater
3. 0. 10 Subway and light rail transportation should be protected according to the local basic intensity. 3.0.11 Classification of site soil types, classification of construction site categories, and identification of foundation soil liquefaction. Subway and light rail transit engineering structures shall comply with the relevant provisions of the current national standard "Code for Seismic Design of Railway Engineering XGBI111". For ground buildings, the current national standard "Code for Seismic Design of Buildings XGBJ11" shall be implemented. The depth of the division shall meet the design needs.
3.0.12 The survey of the depot and its ancillary buildings can be carried out simultaneously with the mainline survey. The survey of ventilation ducts, ventilation shafts and water sources should be carried out during the detailed survey stage. 3.0.13 Monitoring suggestions should be made for the deformation and stress changes of rock mass, the stability of dense rock, the effect of precipitation, the state of the supporting structure, and the impact on adjacent buildings and municipal facilities. Geotechnical naming, description and surrounding rock classification
4.1 Rock classification
4.1.1 Rocks should be divided into igneous rocks, sedimentary rocks and metamorphic rocks according to their genesis. 4.1.2 Rocks shall be classified according to the saturated ultimate compressive strength F, as shown in Table 4.1.2. Table 4.1.2 Classification of rock (MPa)
Sub-rock category
Physical quality rock
Rock quality
Hard rock
Soft rock
Ultra-weathered
4.1.3 The weathering degree of rock shall be classified into unweathered, slightly weathered, moderately weathered, strongly weathered and fully weathered according to Appendix A of this Code.
4.1.4 According to the softening coefficient K, it shall be classified into softened rock K, ≤ 0.75 and non-softened rock K, > 0.75.
Note, K, is the ratio of the rock monosaccharide extreme compressive strength in the saturated state to that in the air-dried state. 4.2 Classification of soils
4.2.1 According to the age of deposition, soils are divided into old sedimentary soils, general sedimentary soils, and recent sedimentary soils, and should meet the following requirements:
Old sedimentary soils: soil layers deposited in the late Pleistocene of the Quaternary Period (before the cultural period). 1
2 General sedimentary soils: soil layers deposited in the Holocene of the Quaternary Period (before the cultural period). Recent sedimentary soils: soil layers deposited recently since the cultural period. 4.2.2 According to geological origin, soils should be divided into residual soils, colliery soils, alluvial soils, alluvial soils, silt soils, glacial soils, and aeolian soils.
4.21.3 According to the organic matter content W. in the soil, soils can be divided into inorganic soils, organic soils, carbonaceous soils, and peat (organic matter content W. is the ignition loss at 550C). Determined according to Table 4.2.3. Table 4.2.3 Classification by organic content (W.) (%) Name
Inorganic soil
Organic soil
Muddy soil
Organic matter content
SAWA10
10<≤60
Classification of soil According to particle gradation, it should be divided into crushed stone soil and sandy soil and should meet the following requirements 4.2.4
Crushed stone soil: soil in which the mass of particles with a particle size greater than 2 mm exceeds 50% of the total mass.
Sand soil: soil with a particle size greater than 2 mm and a mass of particles greater than 0.075 mm exceeding 50% of the total mass. 3 The classification of gravel soil and sand soil should be determined according to Table 4.2.4-1 and Table 4.2, 4-2: Table 4.2.4-1 Classification of gravel soil
Soil name
Number Shape
Circular Sub-circular as the standard
Mainly shaped
Mainly graphic and sub-circular
Angular as the standard
Mainly shaped and sub-shaped
Mainly angular
Number of particles
Mainly shaped and sub-shaped
Mainly angular
Mainly shaped
Number of particles
Mainly shaped and sub-shaped
Mainly angular
Mainly shaped
Mainly shaped
Number of particles
Mainly shaped with a particle size greater than 200 mm exceeding 50% of the total mass.Mainly shaped with a particle size greater than 20 mm exceeding 50% of the total mass.Mainly shaped with a particle size greater than 2 mm exceeding 50% of the total mass.Table 4. 2.4-2 Classification of sandy soil Name of sandy soil Powder content Particles with a diameter greater than 2 mm account for more than 25% of the total mass and less than 50% Particles with a diameter greater than 0.5 mm account for more than 50% of the total mass Particles with a diameter greater than 0.25 mm account for more than 50% of the total mass Particles with a diameter greater than 0.075 mm account for more than 50% of the total mass Particles with a diameter greater than 0.075 mm account for more than 50% of the total mass According to the plasticity index, it can be divided into silt and clay. 4.2.5 Silt: Soil with a plasticity index of 1, greater than 3 and less than or equal to 10 is clay; plasticity index I, greater than 10, is determined according to Table 4.2.5. 2
Table 4. 2. 5 Classification of clay soil
Name of soil
Silty clay
Organization index T.
10≤17
4.2.6 Special soil: According to its special properties, it is divided into collapsible soil, expansive soil, soft soil, residual soil and artificial fill
1 Collapsible soil: It is formed by accumulation in arid and semi-arid environments, with low consolidation degree and large pore age ratio. With the increase of water content or water loss, it will produce significant and large additional compression deformation, mainly loess and loess-like soil. But it also includes some gravel soil, sandy soil and mixed soil formed in similar environments. Collapsible soil is divided into self-weight collapsible soil and non-self-weight collapsible soil.
2 Expansive soil: It contains more or a large amount of hydrophilic clay minerals, and has significant water absorption expansion and water loss shrinkage and reciprocating reversible deformation characteristics. 3 Soft soil: clay soil with natural water content greater than or equal to liquid limit, natural porosity greater than or equal to 1.0, and gray or gray-black appearance, with technical characteristics such as high compressibility (a1-10.5MPa1), low strength (C<30kPa), high sensitivity and low permeability. Clay soil with natural water content greater than liquid limit, porosity greater than or equal to 1.5 and containing a large amount of organic matter is called silt; clay soil with natural porosity less than 1.5 but greater than or equal to 1.0 is called silty soil.
4 Residual soil: the organizational structure of the rock has been completely destroyed, and its mineral components have been completely weathered into soil but not transported except for quartz. Artificial fill: soil filled by human activities, according to its material composition and filling method, can be divided into the following three categories:
1) Plain fill: fill composed of one or more materials such as crushed stone, sand, silt, clay, etc., without impurities or with few impurities. According to the main components, plain fill can be divided into crushed stone plain fill, sandy plain fill, silt-quality fill and clay-quality fill, etc.
2) Miscellaneous fill: fill containing a large amount of construction waste, industrial waste or domestic waste, etc., can be divided into construction waste fill, industrial material fill and domestic waste fill according to the composition of the materials
3) Flushing fill: fill formed by hydraulically moving mud and sand, also known as blowing fill. 4.3 Classification of tunnel surrounding rock
4.3.1 Tunnel surrounding rock should be classified according to Table 4.3.1. Table 4.3.1 Classification of main engineering geological conditions: hard rock (saturated ultimate compressive strength, > soft surface (glass interlayer) type: membrane type; hard rock (F, ≥30MPa); affected by geological structure, structural characteristics and research: basket-shaped block structure (most interlayer) and through-stretch joints, but its occurrence and star-shaped block structure. The combination relationship will not cause sliding. The waist-shaped rock is a medium-sized body structure with few differences. It is a relatively high-quality rock (J, ~30MPa). It is slightly affected by the geological structure and has no joints. The layered rock is palm-shaped (>30MPa). It is affected by the geological structure and has developed soft waists (rate is 5MPa). However, its occurrence and superposition are not known. The layers are body layers or medium-sized layers. The valleys between waists may be soft rocks with relatively high quality (5MPa).9. Site complexity
Radial landform
Opening flat
Balanced site
Medium complex
Miscellaneous site
Complex site
Gentle slope
Basically flat
Procedure
The strata are relatively stable, if the properties do not change much, the groundwater level is relatively high. Generally, the slopes are composed of medium-hard soil or medium-hard soil. The strata change greatly, if the properties are changeable, the groundwater level is high. Generally, the slopes are mostly composed of medium-hard soil and medium-hard soil. The site has a large height difference and the upper surface is complex. The upper surface is soft, the rise is large, and the groundwater level is high. It contains many types of groundwater
3. 0. 10 Subway and light rail transportation should be protected according to the local basic intensity. 3.0.11 Classification of site soil types, classification of construction site categories, and identification of foundation soil liquefaction. Subway and light rail transit engineering structures shall comply with the relevant provisions of the current national standard "Code for Seismic Design of Railway Engineering XGBI111". For ground buildings, the current national standard "Code for Seismic Design of Buildings XGBJ11" shall be implemented. The depth of the division shall meet the design needs.
3.0.12 The survey of the depot and its ancillary buildings can be carried out simultaneously with the mainline survey. The survey of ventilation ducts, ventilation shafts and water sources should be carried out during the detailed survey stage. 3.0.13 Monitoring suggestions should be made for the deformation and stress changes of rock mass, the stability of dense rock, the effect of precipitation, the state of the supporting structure, and the impact on adjacent buildings and municipal facilities. Geotechnical naming, description and surrounding rock classification
4.1 Rock classification
4.1.1 Rocks should be divided into igneous rocks, sedimentary rocks and metamorphic rocks according to their genesis. 4.1.2 Rocks shall be classified according to the saturated ultimate compressive strength F, as shown in Table 4.1.2. Table 4.1.2 Classification of rock (MPa)
Sub-rock category
Physical quality rock
Rock quality
Hard rock
Soft rock
Ultra-weathered
4.1.3 The weathering degree of rock shall be classified into unweathered, slightly weathered, moderately weathered, strongly weathered and fully weathered according to Appendix A of this Code.
4.1.4 According to the softening coefficient K, it shall be classified into softened rock K, ≤ 0.75 and non-softened rock K, > 0.75.
Note, K, is the ratio of the rock monosaccharide extreme compressive strength in the saturated state to that in the air-dried state. 4.2 Classification of soils
4.2.1 According to the age of deposition, soils are divided into old sedimentary soils, general sedimentary soils, and recent sedimentary soils, and should meet the following requirements:
Old sedimentary soils: soil layers deposited in the late Pleistocene of the Quaternary Period (before the cultural period). 1
2 General sedimentary soils: soil layers deposited in the Holocene of the Quaternary Period (before the cultural period). Recent sedimentary soils: soil layers deposited recently since the cultural period. 4.2.2 According to geological origin, soils should be divided into residual soils, colliery soils, alluvial soils, alluvial soils, silt soils, glacial soils, and aeolian soils.
4.21.3 According to the organic matter content W. in the soil, soils can be divided into inorganic soils, organic soils, carbonaceous soils, and peat (organic matter content W. is the ignition loss at 550C). Determined according to Table 4.2.3. Table 4.2.3 Classification by organic content (W.) (%) Name
Inorganic soil
Organic soil
Muddy soil
Organic matter content
SAWA10
10<≤60
Classification of soil According to particle gradation, it should be divided into crushed stone soil and sandy soil and should meet the following requirements 4.2.4
Crushed stone soil: soil in which the mass of particles with a particle size greater than 2 mm exceeds 50% of the total mass.
Sand soil: soil with a particle size greater than 2 mm and a mass of particles greater than 0.075 mm exceeding 50% of the total mass. 3 The classification of gravel soil and sand soil should be determined according to Table 4.2.4-1 and Table 4.2, 4-2: Table 4.2.4-1 Classification of gravel soil
Soil name
Number Shape
Circular Sub-circular as the standard
Mainly shaped
Mainly graphic and sub-circular
Angular as the standard
Mainly shaped and sub-shaped
Mainly angular
Number of particles
Mainly shaped and sub-shaped
Mainly angular
Mainly shaped
Number of particles
Mainly shaped and sub-shaped
Mainly angular
Mainly shaped
Mainly shaped
Number of particles
Mainly shaped with a particle size greater than 200 mm exceeding 50% of the total mass.Mainly shaped with a particle size greater than 20 mm exceeding 50% of the total mass.Mainly shaped with a particle size greater than 2 mm exceeding 50% of the total mass.Table 4. 2.4-2 Classification of sandy soil Name of sandy soil Powder content Particles with a diameter greater than 2 mm account for more than 25% of the total mass and less than 50% Particles with a diameter greater than 0.5 mm account for more than 50% of the total mass Particles with a diameter greater than 0.25 mm account for more than 50% of the total mass Particles with a diameter greater than 0.075 mm account for more than 50% of the total mass Particles with a diameter greater than 0.075 mm account for more than 50% of the total mass According to the plasticity index, it can be divided into silt and clay. 4.2.5 Silt: Soil with a plasticity index of 1, greater than 3 and less than or equal to 10 is clay; plasticity index I, greater than 10, is determined according to Table 4.2.5. 2
Table 4. 2. 5 Classification of clay soil
Name of soil
Silty clay
Organization index T.
10≤17
4.2.6 Special soil: According to its special properties, it is divided into collapsible soil, expansive soil, soft soil, residual soil and artificial fill
1 Collapsible soil: It is formed by accumulation in arid and semi-arid environments, with low consolidation degree and large pore age ratio. With the increase of water content or water loss, it will produce significant and large additional compression deformation, mainly loess and loess-like soil. But it also includes some gravel soil, sandy soil and mixed soil formed in similar environments. Collapsible soil is divided into self-weight collapsible soil and non-self-weight collapsible soil.
2 Expansive soil: It contains more or a large amount of hydrophilic clay minerals, and has significant water absorption expansion and water loss shrinkage and reciprocating reversible deformation characteristics. 3 Soft soil: clay soil with natural water content greater than or equal to liquid limit, natural porosity greater than or equal to 1.0, and gray or gray-black appearance, with technical characteristics such as high compressibility (a1-10.5MPa1), low strength (C<30kPa), high sensitivity and low permeability. Clay soil with natural water content greater than liquid limit, porosity greater than or equal to 1.5 and containing a large amount of organic matter is called silt; clay soil with natural porosity less than 1.5 but greater than or equal to 1.0 is called silty soil.
4 Residual soil: the organizational structure of the rock has been completely destroyed, and its mineral components have been completely weathered into soil but not transported except for quartz. Artificial fill: soil filled by human activities, according to its material composition and filling method, can be divided into the following three categories:
1) Plain fill: fill composed of one or more materials such as crushed stone, sand, silt, clay, etc., without impurities or with few impurities. According to the main components, plain fill can be divided into crushed stone plain fill, sandy plain fill, silt-quality fill and clay-quality fill, etc.
2) Miscellaneous fill: fill containing a large amount of construction waste, industrial waste or domestic waste, etc., can be divided into construction waste fill, industrial material fill and domestic waste fill according to the composition of the materials
3) Flushing fill: fill formed by hydraulically moving mud and sand, also known as blowing fill. 4.3 Classification of tunnel surrounding rock
4.3.1 Tunnel surrounding rock should be classified according to Table 4.3.1. Table 4.3.1 Classification of main engineering geological conditions: hard rock (saturated ultimate compressive strength, > soft surface (glass interlayer) type: membrane type; hard rock (F, ≥30MPa); affected by geological structure, structural characteristics and research: basket-shaped block structure (most interlayer) and through-stretch joints, but its occurrence and star-shaped block structure. The combination relationship will not cause sliding. The waist-shaped rock is a medium-sized body structure with few differences. It is a relatively high-quality rock (J, ~30MPa). It is slightly affected by the geological structure and has no joints. The layered rock is palm-shaped (>30MPa). It is affected by the geological structure and has developed soft waists (rate is 5MPa). However, its occurrence and superposition are not known. The layers are body layers or medium-sized layers. The valleys between waists may be soft rocks with relatively high quality (5MPa).9. Site complexity
Radial landform
Opening flat
Balanced site
Medium complex
Miscellaneous site
Complex site
Gentle slope
Basically flat
Procedure
The strata are relatively stable, if the properties do not change much, the groundwater level is relatively high. Generally, the slopes are composed of medium-hard soil or medium-hard soil. The strata change greatly, if the properties are changeable, the groundwater level is high. Generally, the slopes are mostly composed of medium-hard soil and medium-hard soil. The site has a large height difference and the upper surface is complex. The upper surface is soft, the rise is large, and the groundwater level is high. It contains many types of groundwater
3. 0. 10 Subway and light rail transportation should be protected according to the local basic intensity. 3.0.11 Classification of site soil types, classification of construction site categories, and identification of foundation soil liquefaction. Subway and light rail transit engineering structures shall comply with the relevant provisions of the current national standard "Code for Seismic Design of Railway Engineering XGBI111". For ground buildings, the current national standard "Code for Seismic Design of Buildings XGBJ11" shall be implemented. The depth of the division shall meet the design needs.
3.0.12 The survey of the depot and its ancillary buildings can be carried out simultaneously with the mainline survey. The survey of ventilation ducts, ventilation shafts and water sources should be carried out during the detailed survey stage. 3.0.13 Monitoring suggestions should be made for the deformation and stress changes of rock mass, the stability of dense rock, the effect of precipitation, the state of the supporting structure, and the impact on adjacent buildings and municipal facilities. Geotechnical naming, description and surrounding rock classification
4.1 Rock classification
4.1.1 Rocks should be divided into igneous rocks, sedimentary rocks and metamorphic rocks according to their genesis. 4.1.2 Rocks shall be classified according to the saturated ultimate compressive strength F, as shown in Table 4.1.2. Table 4.1.2 Classification of rock (MPa)
Sub-rock category
Physical quality rock
Rock quality
Hard rock
Soft rock
Ultra-weathered
4.1.3 The weathering degree of rock shall be classified into unweathered, slightly weathered, moderately weathered, strongly weathered and fully weathered according to Appendix A of this Code.
4.1.4 According to the softening coefficient K, it shall be classified into softened rock K, ≤ 0.75 and non-softened rock K, > 0.75.
Note, K, is the ratio of the rock monosaccharide extreme compressive strength in the saturated state to that in the air-dried state. 4.2 Classification of soils
4.2.1 According to the age of deposition, soils are divided into old sedimentary soils, general sedimentary soils, and recent sedimentary soils, and should meet the following requirements:
Old sedimentary soils: soil layers deposited in the late Pleistocene of the Quaternary Period (before the cultural period). 1
2 General sedimentary soils: soil layers deposited in the Holocene of the Quaternary Period (before the cultural period). Recent sedimentary soils: soil layers deposited recently since the cultural period. 4.2.2 According to geological origin, soils should be divided into residual soils, colliery soils, alluvial soils, alluvial soils, silt soils, glacial soils, and aeolian soils.
4.21.3 According to the organic matter content W. in the soil, soils can be divided into inorganic soils, organic soils, carbonaceous soils, and peat (organic matter content W. is the ignition loss at 550C). Determined according to Table 4.2.3. Table 4.2.3 Classification by organic content (W.) (%) Name
Inorganic soil
Organic soil
Muddy soil
Organic matter content
SAWA10
10<≤60
Classification of soil According to particle gradation, it should be divided into crushed stone soil and sandy soil and should meet the following requirements 4.2.4
Crushed stone soil: soil in which the mass of particles with a particle size greater than 2 mm exceeds 50% of the total mass.
Sand soil: soil with a particle size greater than 2 mm and a mass of particles greater than 0.075 mm exceeding 50% of the total mass. 3 The classification of gravel soil and sand soil should be determined according to Table 4.2.4-1 and Table 4.2, 4-2: Table 4.2.4-1 Classification of gravel soil
Soil name
Number Shape
Circular Sub-circular as the standard
Mainly shaped
Mainly graphic and sub-circular
Angular as the standard
Mainly shaped and sub-shaped
Mainly angular
Number of particles
Mainly shaped and sub-shaped
Mainly angular
Mainly shaped
Number of particles
Mainly shaped and sub-shaped
Mainly angular
Mainly shaped
Mainly shaped
Number of particles
Mainly shaped with a particle size greater than 200 mm exceeding 50% of the total mass.Mainly shaped with a particle size greater than 20 mm exceeding 50% of the total mass.Mainly shaped with a particle size greater than 2 mm exceeding 50% of the total mass.Table 4. 2.4-2 Classification of sandy soil Name of sandy soil Powder content Particles with a diameter greater than 2 mm account for more than 25% of the total mass and less than 50% Particles with a diameter greater than 0.5 mm account for more than 50% of the total mass Particles with a diameter greater than 0.25 mm account for more than 50% of the total mass Particles with a diameter greater than 0.075 mm account for more than 50% of the total mass Particles with a diameter greater than 0.075 mm account for more than 50% of the total mass According to the plasticity index, it can be divided into silt and clay. 4.2.5 Silt: Soil with a plasticity index of 1, greater than 3 and less than or equal to 10 is clay; plasticity index I, greater than 10, is determined according to Table 4.2.5. 2
Table 4. 2. 5 Classification of clay soil
Name of soil
Silty clay
Organization index T.
10≤17
4.2.6 Special soil: According to its special properties, it is divided into collapsible soil, expansive soil, soft soil, residual soil and artificial fill
1 Collapsible soil: It is formed by accumulation in arid and semi-arid environments, with low consolidation degree and large pore age ratio. With the increase of water content or water loss, it will produce significant and large additional compression deformation, mainly loess and loess-like soil. But it also includes some gravel soil, sandy soil and mixed soil formed in similar environments. Collapsible soil is divided into self-weight collapsible soil and non-self-weight collapsible soil.
2 Expansive soil: It contains more or a large amount of hydrophilic clay minerals, and has significant water absorption expansion and water loss shrinkage and reciprocating reversible deformation characteristics. 3 Soft soil: clay soil with natural water content greater than or equal to liquid limit, natural porosity greater than or equal to 1.0, and gray or gray-black appearance, with technical characteristics such as high compressibility (a1-10.5MPa1), low strength (C<30kPa), high sensitivity and low permeability. Clay soil with natural water content greater than liquid limit, porosity greater than or equal to 1.5 and containing a large amount of organic matter is called silt; clay soil with natural porosity less than 1.5 but greater than or equal to 1.0 is called silty soil.
4 Residual soil: the organizational structure of the rock has been completely destroyed, and its mineral components have been completely weathered into soil but not transported except for quartz. Artificial fill: soil filled by human activities, according to its material composition and filling method, can be divided into the following three categories:
1) Plain fill: fill composed of one or more materials such as crushed stone, sand, silt, clay, etc., without impurities or with few impurities. According to the main components, plain fill can be divided into crushed stone plain fill, sandy plain fill, silt-quality fill and clay-quality fill, etc.
2) Miscellaneous fill: fill containing a large amount of construction waste, industrial waste or domestic waste, etc., can be divided into construction waste fill, industrial material fill and domestic waste fill according to the composition of the materials
3) Flushing fill: fill formed by hydraulically moving mud and sand, also known as blowing fill. 4.3 Classification of tunnel surrounding rock
4.3.1 Tunnel surrounding rock should be classified according to Table 4.3.1. Table 4.3.1 Classification of main engineering geological conditions: hard rock (saturated ultimate compressive strength, > soft surface (glass interlayer) type: membrane type; hard rock (F, ≥30MPa); affected by geological structure, structural characteristics and research: basket-shaped block structure (most interlayer) and through-stretch joints, but its occurrence and star-shaped block structure. The combination relationship will not cause sliding. The waist-shaped rock is a medium-sized body structure with few differences. It is a relatively high-quality rock (J, ~30MPa). It is slightly affected by the geological structure and has no joints. The layered rock is palm-shaped (>30MPa). It is affected by the geological structure and has developed soft waists (rate is 5MPa). However, its occurrence and superposition are not known. The layers are body layers or medium-sized layers. The valleys between waists may be soft rocks with relatively high quality (5MPa).The groundwater level is relatively high. ... The investigation of ventilation ducts, ventilation shafts and water sources should be carried out during the detailed investigation stage. 3.0.13 Monitoring suggestions should be made for the deformation and stress changes of rock mass, the stability of dense rock, the effect of precipitation, the state of supporting structures, and the impact on adjacent buildings and municipal facilities. Geotechnical naming, description and surrounding rock classification
4.1 Rock classification
4.1.1 Rocks should be divided into igneous rocks, sediment30MPa), the amount of acidification and inhibition of the most light
is very developed, the soft stage bacteria
model stone (5MP=<), ≤30MPa) the amount of land inspection has a greater impact on the location, the series of development
t: I. dense clay and cemented sand 2. loess (Q1.Q)
3. -- General or cemented phosphate and pebble soil, lacking inter-soil
stone medical rock is located in the fracture zone with strong pressure; cracks are disorderly, it is stone-soil or soil-soil-like
general Quaternary system hard to hard clay and fine soil and fine soil
good|| general broken, pebble soil, moldy carbon, agent
special + and edible ± (Q, Q.)
the latter texture is located in the fracture zone with strong compression, it is angular, sandy, soft
soft organized clay and silt, the period is cautious Such as fine yarn Wu huge block
overall structure
rock opening after
fixed state
[sugar can be the front sound library: see
friction end time long
period increase slight weight fixed,
elegant Shang sales integrated
most glycoside waist, pre-board male cigarette
Man block (stone)
accurate (stone) shape inlay
scattered structure
maximum change
turn over estimation structure
holy drunk stone shape|| tt||Compressed structure
Block (stone)
Crushed (stone) shape
Embedded structure
.2 Villa
Overall plant structure
Although angular (gravel)
Crushed (stone) shape loose
Dispersed structure
Show loose number or
It is loose
Viscous soil
Dynamic education
When there is no change in the part
, it can produce small good exhaustion, marrow
The whole basic sugar Note: When the surrounding rock of soft rock encounters groundwater, the national 4.4 soil and rock excavability classification can be appropriately reduced according to specific conditions and working conditions. 4.4.1 Soil and rock excavability can be divided into loose soil, ordinary soil, hard soil, soft rock, sub-hard rock and hard rock according to Appendix B of this code.
4.5 Description of rock and soil
4.5.1 The rock shall be described in terms of name, color, composition, structure and texture, degree of weathering, degree of joint development, fillings, presence or absence of dyke intrusion, etc. 4.5.2 The crushed stone shall be described in terms of particle size distribution, shape, parent rock composition, degree of weathering, fillings and filling degree, density, bedding characteristics, etc. 4.5.3 The sand shall be described in terms of color, particle size distribution, mineral composition, shape, clay content, moisture, density and bedding characteristics, etc. The density of the sand shall be determined according to the standard penetration test number N value in accordance with Table 4.5.3-1. The density of the silt shall be determined according to the porosity in accordance with Table 4.5.3-2.
Table 4.5.3-1 Density of sandy soil
Density
Density
Table 4.5.3-2 Density of silt
0.75e0.90
4.5.4 Silt should be described in terms of color, content, visibility, density and bedding characteristics. The moisture content of silt shall be determined according to Table 4.5.4
Table 4.5. Moisture content of silt determined by iodine according to water content (%)W
4.5.5 Clay should be described in terms of color, content, soil structure and structural properties, bedding characteristics and state, cross-sectional state. The state of clay shall be determined according to the liquid index 1t according to Table 4.5.5.
Table 4. Sugar content of S.S clay soil state
0. 00<≤0. 25
0.2540.75
0. 25≤1. 00
4. 5. 6 Special soils should be described in terms of their special composition, state and structural characteristics. 5 Work content of the investigation stage
General provisions
5. 1. 1 The geotechnical engineering design work stage of subway and light rail transit should be divided into the feasibility study stage, preliminary investigation stage, detailed investigation stage and geotechnical engineering investigation work during construction.
5. 1. 2 The engineering geological and hydrogeological data provided in each investigation stage must meet the design parameters and relevant technical data required by the corresponding design stage, and the engineering environment should be predicted and evaluated.
2 - 13-— 7
Feasibility Study Phase
5.2. 1 In the feasibility study phase, relevant survey data should be investigated and collected, and exploration work can be carried out appropriately when necessary.
5.2.2 The work in the feasibility study phase should include the following contents: Before the survey, a work plan should be formulated based on the survey task book proposed by the construction unit and the design personnel.
Relevant data on regional geological structure, engineering geology, hydrogeology, meteorology, earthquake, geomorphology, groundwater dynamics, ancient river channels, as well as geophysical data and relevant pictures (satellite images, aerial photographs) should be collected.
3 The foundation data of important and tall buildings along the line and the construction experience of geotechnical engineering along the line should be investigated and studied.
4 Each station, section, and each geomorphic unit should have exploration data. A certain number of observation holes can be arranged for long-term observation of groundwater dynamics. 5
Evaluate and select the schemes. The following documents should be submitted in the feasibility study stage: 5.2.3
Geotechnical engineering investigation report in the feasibility study stage. 1
Drilling plane location map.
Engineering geological longitudinal section map.
Necessary test data and drawings and tables.
Engineering geology, hydrogeology and municipal environmental data of complex areas. 5
5. 3 Preliminary investigation stage
In the preliminary investigation stage, the regional geology, hydrogeology and engineering geology conditions along the line should be preliminarily identified, and the engineering geology and hydrogeology conditions of the area through which the line passes should be evaluated; the nature, characteristics and scope of the unfavorable geology and special geology that control the line plan should be preliminarily identified, and preliminary treatment measures for the unfavorable geology should be proposed. 5.3.2 The preliminary investigation stage should include the following contents: Preliminary investigation of the geological conditions, landforms, strata, lithology, geological structure, hydrogeological conditions, and underground harmful gases in the area along the line. Delineate the complex structural areas, unfavorable geological and special geological areas, and preliminarily investigate their causes, types, properties, occurrence, development, distribution laws and the degree of harm to the line, and put forward treatment suggestions.
3 Preliminary investigation of the development and distribution of river and lake sediments along the line, ancient building sites, and put forward preliminary evaluations in combination with engineering requirements.
Investigate the foundation conditions, foundation types, superstructures and usage status of important buildings along the line, and predict the changes and preventive measures that may be caused by the construction of the subway. Analyze the existing ground capsule data, and classify the site soil types and site categories. 5
Identify the digging properties of soil and stone along the line and the classification of ring rocks. 6
7 For important stations, sections and bad sections along the line, separate survey data can be provided when necessary.
8 Preliminary investigation of the surface water level, flow, water quality, and the relationship between the recharge and discharge conditions and groundwater along the line.
9 Preliminary investigation of groundwater type, burial conditions, recharge source, highest water level in previous years, water quality, flow velocity, and flow direction, understand the dynamic and periodic change of groundwater, propose water quality evaluation, and conduct hydrogeological zoning.
10 Select representative sections according to geomorphic units for hydrogeological tests and propose relevant technical parameters. When it is necessary to observe the dynamics of groundwater, long-term observation holes should be set up. 5.3.3 The exploration work in the preliminary survey stage should comply with the following provisions: It is advisable to cross-distribute points on one side or both sides of the road, and when it is necessary to drill holes within the tunnel range, the holes should be backfilled and sealed. The spacing between exploration points should be 100 to 200 meters, and can be determined according to the complexity of geological conditions and design needs.
2 The number of holes for taking test samples and conducting in-situ tests should not be less than 2/3 of the total number of exploration holes.
3 Depth of controlled exploration holes: In loose strata, it should not be less than 20m below the bottom plate of the tunnel structure. In slightly weathered and moderately weathered rock strata, the hole depth should be 3 to 5m below the bottom plate. In strongly weathered and fully weathered zones, the depth of exploration can be determined according to geological conditions, design and construction requirements.
2—13—8
5.4 Detailed exploration stage
5.4.1 According to the preliminary design appraisal opinion, the engineering geology and hydrogeology conditions along the line should be investigated in detail.
5.4.2 The detailed investigation stage should include the following contents: For sections with complex engineering geology and hydrogeology, special sections or sections with special construction requirements, key investigations should be carried out, and evaluation and treatment plans should be proposed. Separate detailed investigations should be carried out for stations, entrances and exits, ventilation ducts, water source wells, vehicle depots, etc.
3 There should be no less than 3 cross-sections of the station. Cross-sections should be arranged in sections with complex geological conditions.
4 Based on the engineering geology and hydrogeology conditions, combined with the requirements of design and construction methods, the technical parameters required for the design should be proposed by stratification based on the comprehensive indicators of stations and sections using mathematical and statistical methods.
5 Identify the hydrogeological conditions, supplement the deficiencies of the preliminary investigation, further identify the nature of the groundwater, and make an evaluation. When precipitation construction is required, precipitation methods and related calculation parameters should be proposed for stations and sections.
Analyze the stability of buildings, underground structures and pipelines along the line during the construction process, and propose protective measures
The number of exploration points and the depth of exploration holes in the detailed investigation stage should meet the following requirements5.4.3
1 The distance between exploration holes can be determined according to Table 5.4.3: Table 5.4.3 Spacing between sensitive exploration holes (m)
Southern single site
Medium and complex site
Complex site
100~50
80~ 40
Exploration hole depth
1) The depth of the control borehole in the Quaternary loose strata should be determined according to the depth of the section and station, geological conditions such as strata and groundwater, design requirements, construction methods and the needs of precipitation engineering. Other boreholes can be drilled to 6~10m below the foundation. 2) Control boreholes in bedrock areas: slightly weathered zones should be drilled 3~~5m, but each station and section must have a borehole that enters 1~3m below the basement. In the moderately weathered zone, it should enter 3~5m below the basement. 3 The number of sampling test and in-situ test holes should not be less than 1/2 of the total number of exploration holes. 4 When necessary, hydrogeological tests should be carried out at each station, section and each geomorphic unit. 5 Water source well exploration should be carried out according to design requirements. 6 The line survey within the depot should be carried out in accordance with the relevant provisions of Chapter 15 of this specification. In addition to drawing geological longitudinal agent maps, geological cross-section maps should also be drawn when necessary. The exploration depth can be drilled to 4 to 8 meters below the basement. It can be appropriately deepened when the geological conditions are complex or there are special requirements.
5. 4.4 Hydrogeological data such as groundwater type, recharge and discharge conditions, flow velocity, flow direction, permeability coefficient, highest water level in previous years, low water level, water level during investigation, and water quality along the line should be provided for each station and section.
5. 5 Geotechnical engineering investigation during construction The geotechnical engineering investigation during construction should include the following contents: 5. 5.1
Verify the accuracy of the investigation data and adjust the technical parameters provided in the investigation report in a timely manner according to the actual situation.
Solve the engineering geological and hydrogeological problems encountered during construction. Monitor the ground subsidence of important tall buildings along the line and nearby areas. 3
Draw the completed geological profile of the tunnel.
Carry out long-term observation of groundwater dynamics.
Carry out rock mass stress and deformation observation in the shale or masonry. 6 Engineering geological survey and mapping
Engineering geological survey and mapping should adopt the following methods: 6.0.1
Analyze and study the existing geological data according to the task requirements and compile an outline. If necessary, select representative areas for field survey. For the Quaternary covered areas where the line is located, it is advisable to use geophysical exploration methods to conduct exploration first. The interpretation results should be selectively verified, and measured geological profiles and necessary geotechnical testing data should be provided.
3 For areas with exposed bedrock and semi-exposed bedrock, the route geological tracing method combined with the cross-cutting method should be used for investigation and mapping. If necessary, appropriate exploration and testing can be carried out. 4 For complex geology, it is advisable to use the mapping method. When the geological conditions are simple or the existing geological data are relatively sufficient, the mapping method can be used. The mapping area should have 1/3 of the total number of cuts.
5 For geological problems that have an important impact on the design and construction of the line, set up special topics for research.
. The scope of geological survey and mapping of the project shall comply with the following provisions; 6.0.2
1 The work shall be carried out according to the planned line, the adjacent buildings (structures) and the adjacent areas.
2 The width of the extension from the center line of the line to both sides shall not be less than 100m for stations and curves, and not less than 50m for straight sections.
The area determined to meet the needs of line scheme comparison and site selection of adjacent buildings, and the scope that may be affected by geological disasters caused by engineering construction. The scope extended to study and solve the adverse engineering geology and special geology that affect engineering construction,
The area that directly or potentially harms the stability and suitability of the line due to the influence of fault structures, underground water retention areas, radioactive ore bodies, contaminated soil and similar underground projects, or the area where the foundation of the building has affected the reasonable burial depth of the line. 6
The scope determined when it is necessary to compare the engineering geological conditions of two areas. When the geological conditions are particularly complex, the scope of the expanded investigation and mapping is determined. I. The geological survey and mapping includes the following contents: Study the basic characteristics of the landform, classify the basic genetic type and genetic morphological type of the landform, and analyze its relationship with the basement lithology and neotectonic movement. 2 Investigate the liquefiable soil layer and the main new and old accumulations, and the engineering geological characteristics of special soil. 3 The lithological characteristics of the rock layer and rock mass should be divided into geological units according to their genesis and rock mass structure, and understand the weathering degree and rock solidity of the rock. 4. Investigate the type, morphology, occurrence and distribution of structural inflammation. Classify the fractures and joints, and determine the relationship between the strike of the main structural surface and the angle of the line. For the main fractures and strong fracture zones, appropriate exploration and testing should be carried out to investigate the morphology, scale, material composition of the weak structural surface, and the degree of harm to the stability of the tunnel rock caused by the softening effect of groundwater.
6 Investigate the evolution history of surface water and riverbed, and collect the highest flood level, flow rate, flow rate, and flooding range of the main rivers. Investigate the types, basic characteristics, recharge sources and discharge conditions of groundwater, as well as the dynamic changes of groundwater and the connection with the surface water system. Evaluate whether groundwater is corrosive to concrete and steel structures. Investigate the formation, form, scale, distribution, development trend and impact of adverse geological phenomena such as karst, landslide, tidal field, shore scour, underground ancient river channel, dark bay, and methane-containing strata on project construction.
8 Investigate the historical earthquake activity according to the basic earthquake intensity zoning data, and divide the sections that are favorable, unfavorable or dangerous for engineering construction. 9 Investigate the scope, causes and development trends of ground subsidence that has occurred or may occur along the line and its vicinity.
10 Investigate the impact of the line and its surrounding buildings (structures) on engineering construction, and evaluate the stability of the site.
11 When the line passes through the goaf, collect information and conduct investigations and visits. Determine the scope of the constructed goaf and the designed goaf, understand its scale, cavern burial depth and the stability of the H overburden rock and soil layer, and conduct geophysical testing and drilling verification. Investigate the soil and rock composition and digging grade of different sections of the line. 12
13 Search for local hydrological, meteorological, vegetation and soil freezing depth data. The scale and accuracy of engineering geological surveying and mapping shall meet the following requirements: 6. 0. 4
The scale of the surveying and mapping map shall use a line topographic map one level larger than the final result map as the base map. In the feasibility study and investigation stage, 111000~1:2000 shall be used; in the preliminary investigation stage or detailed investigation stage, 1:500~~1:1000 shall be used: the scale shall be appropriately enlarged in the sections with complex engineering geological conditions.
2 In the feasibility study and investigation stage, the stratigraphic units are divided into "stage" or "group"; the rock mass age units are divided into "period"; in the preliminary investigation stage or detailed investigation stage, they are divided into "segments". The Quaternary system should be divided into different genetic types, and the era should be divided into "systems". The position error of geological boundaries and geological observation points on the map should not exceed 2mm of the map scale. When the width of the geological unit on the map is equal to or greater than 2mm, it should be indicated on the map. For geological units with special significance or important impact on the project, when the width on the map is less than 2mm, the over-scale method should be used to appropriately expand the mark and add annotate. 6.0.5 The arrangement of geological observation points shall meet the following requirements: 1 Geological observation points shall be arranged on different types of geological boundaries, and there shall be an appropriate number of geological observation points in areas with adverse geological phenomena and special geological distribution. 2 Geological observation points shall make use of rock outcrops. When rock outcrops are scarce, a certain number of exploration points shall be arranged.
3 The density of geological observation points shall be determined comprehensively based on technical requirements, the complexity of geological conditions and the scale of mapping. Its density shall be able to control the changes of different types of geological boundaries and geological units.
The original data of engineering geological survey and mapping shall be accurate and reliable, and the pictures and texts shall be consistent. 6.0.6
Engineering geological phenomena that have an impact on engineering design and construction shall be photographed in color and accompanied by text descriptions.
Representative cores can be selected by station, section or geological unit. 6. 0.7
The cores should be properly preserved, and color photos and explanations should be taken. 6. 0.8The main results submitted for engineering geological survey and mapping should include the actual material map of the whole line, engineering geological zoning map, tunnel rock classification plan map, vertical and horizontal geological agent map of the line, geotechnical test results list, photos and comprehensive engineering geological data, survey and mapping report.
Exploration and sampling
7. 1 The most important regulations
7.1.1Exploration and sampling work should be carried out according to the task requirements to ensure that the stratification is accurate and the sampling complies with the regulations, and the data must be complete and reliable. 7. 1.2 The selection of drilling, parallel exploration, trenching and other methods should be determined according to the formation, depth, sampling, in-situ testing and site status.
7.1.3The method of taking geotechnical samples should be determined in combination with the formation conditions and geotechnical test technical requirements.
The exploration work should consider the impact on the project and the surrounding environment, and the distribution of various underground pipelines and underground structures should be understood. Drilling holes, exploration wells, and exploration trenches should be backfilled in time after use.
7.2 Drilling
7.2.1 The drilling method can be selected according to the soil type, water sampling, soil sampling, in-situ testing and groundwater observation requirements, and should meet the following requirements: 1 According to the characteristics of the project, design requirements and geological conditions, rotary, impact, vibration and other drilling methods can be used.
Drilling should be carried out according to the single-hole technical requirements. 2
Dry drilling should be carried out when drilling holes to identify strata and natural gingival depths or when layered observation and measurement of groundwater levels and water sampling are required.
2—13 - 9
4 The drilling footage should be determined according to the formation and the length of the drill bit, under the premise of ensuring accurate geological data: when drilling in the cohesive and silty soil layers, the drilling footage should not exceed the length of the drill bit or the drill pipe. When drilling in sand and gravel soil, the drilling footage should be controlled to ensure the requirements of stratification and description. When drilling in rock, the drilling footage should not exceed the clearance length of the core tube. If necessary, the drilling footage or the time of each drilling can be limited. 7.2.2 The hole diameter should be determined according to the purpose and use of drilling. 7.2.3 The allowable error of drilling depth, rock and soil stratification interface depth, and groundwater level measurement is ±20mm
7. 2. 42 The core sampling rate should meet the requirements of the survey and design tasks. When it is necessary to determine the rock quality index (RQD), a 75mm caliber (N type) double-layer core tube and diamond drill bit should be used.
7.2.5 For important boreholes, cores and soil samples should be preserved and color photographs should be taken in sections.
7.3 Joint exploration and trench exploration
7.3.1 In areas or locations where drilling is difficult, such as densely packed buildings, complex underground pipe networks, and pebble formations, and when it is technically reasonable, the excavation method can be used, and it is advisable to carry out above the groundwater level.
7.3.2 Joint exploration should adopt a circular or square section, and sampling in the well should be carried out in a timely manner with the excavation work. When advancing in loose formations, the wall should be protected, and an inspection hole should be set every 0.5~1.0m. During joint operation, air should be supplied to the joint according to the actual situation, and the harmful gas content in the joint should be monitored.
7.3.3 The description and record of joint exploration and trench exploration should be carried out in accordance with the relevant provisions of Chapter 4 of this Code.
The quality level of soil samples shall be divided into four levels according to the purpose according to Table 7.4.1: Table 7.4.1 Soil sample quality level
Degree of excellence
Non-excellent
Slight disturbance
Excellent disturbance
Excellent disturbance
Test content
Classification, water content, density, strength test, acid test: Classification, water sensitivity, disease degree
Soil type classification, water dispersion
Soil type classification
7.4.2 The sampling tools and methods shall be selected according to the quality level of soil samples and the type of soil according to the relevant provisions of the current national standard "Geotechnical Engineering Investigation Code XGB 50021". Sampling of special soils shall comply with Section 11 of this Code. 7.4.3 For sampling of original soil, static pressure injection method should be adopted, and for sampling of original sand, sand sampling device should be used. 7.4.4 For sampling requirements of special test items, the requirements shall be implemented according to Table 7.4.4. Table 7.4. Soil sampling requirements for special test items Test item Specific heat capacity, thermal conductivity coefficient, conductivity coefficient, bed coefficient Number of samples required The number of samples taken on sand should be greater than 0.025ml for the test and its water content should be maintained. The density of the soil should be indicated. The sample should be greater than the test sample 1, XD×H(cm)15×10×5 - Note The sand should be placed in a closed group or group of blocks, and the other blocks should be greater than the diameter of the test piece 2.5cm × high strength medium
5.5cm and then processed into test piece size, the surface net light viscosity stop sample should be
vertical blood bed sound number, seven, two, disturbed sand is small to Xie late original soil, sand sample can be
soil sample quantity requirements, horizontal bed system failure interval 1, all should indicate the groundwater level
dynamic modulus and damping ratio of each simple, sand is not less than 10x, indicate the degree of water content, and should indicate the groundwater level 7. 5 geophysical exploration
disturbed sample, position indicate density
seven original soil, sand
dare to disturb sample
7.5. 1 When using geophysical exploration methods, the following conditions should be met: 1. There is an obvious difference in physical properties between the object being explored and the rock mass; 2. The object being explored has a certain burial depth and scale, and the geophysical anomaly has sufficient strength. 3. It can suppress various interferences and distinguish useful signals from interference signals. 7.5. 2 The characteristics and application scope of various geophysical exploration methods shall comply with the relevant provisions of Appendix C of 2 13-10 of this Code. 7.5.3 When applying geophysical exploration methods, a method validity test should be carried out, and the test area should be selected in an area that is representative of the comparative data. 7.5.4 The results of geophysical exploration should be compared and verified according to the nature and requirements of the task.
8 Groundwater
8. 1 General provisions
8. 1. 1 The hydrogeological conditions along the line related to the project should be identified in the geotechnical survey of subway and light rail transportation, and the role and influence of groundwater on rock and soil and buildings should be evaluated according to the needs of the project and the characteristics of hydrogeology, and the possible consequences of groundwater on the construction of the project should be predicted and preventive measures should be proposed. 8. 2 Investigation and evaluation
8.2.1 The highest water level, the lowest water level and the recharge water level of the past years should be investigated, and the groundwater level, the water and aquifer level, the hydraulic connection and recharge conditions between groundwater and surface water should be identified in layers, the permeability of the relevant strata should be measured, and the impact of groundwater on the project should be evaluated according to the following contents!
1 Evaluate the adverse effects of the deformation of buildings on both sides, the sinking and subsidence of municipal roads, the changes in groundwater dynamics, and the deformation of underground pipelines and various facilities caused by the construction of drainage measures, and propose preventive measures. 2 When there is a confined water aquifer under the foundation pit, evaluate the impact of the confined water head on the stability of the foundation pit.
3 When the line passes through the water-containing fine sand and silt layer, evaluate the possibility of excavation causing erosion, sand flow and soil gushing.
4 Evaluate the effect of groundwater on the softening, collapse, collapse and erosion of the soil, and recommend anti-floating calculation when necessary.
5 Investigate the water filling conditions of civil air defense projects and artificial caverns along the line, and evaluate the impact on the foundation pit and tunnel.
Evaluate the impact of groundwater on the stability of retaining structures, road temporary structures, slopes and roadbeds. 6
8.2.2 For relevant water-containing, water samples should be taken for water quality analysis to evaluate the erosion of groundwater quality on building materials. The evaluation standards should comply with the provisions of the current national standards.
8.3 Measurement of groundwater parameters
About. 3.1 Items for measuring groundwater parameters are determined according to project needs and rock and soil characteristics. 8.3.2 Groundwater level can be measured during drilling and exploration.And should comply with the following provisions; 1
For all the boreholes and exploration wells for underground water, the initial water level and static water level should be measured. The water level of multi-layer aquifers should be measured in layers by taking water-stopping measures. The pressure head of the pressure-bearing aquifer should be measured.
2 The pumping test hole must be cleaned in time. The natural static water level should be measured before the pumping test.
8.3.3 The flow of groundwater should be determined by geometric method using the isowater level line diagram. The true flow rate of groundwater can be determined by the indicator method. 8.3.4 The infiltration coefficient and water conduction step of the aquifer should be obtained by drilling or exploration and pumping test and water injection test; the water avoidance of the aquifer is divided according to the seepage avoidance coefficient according to Table 8.3.4.
Table 8.3.4
Category Special effects Relict water
Xian permeable water
>200.000l
Water permeability of water-bearing belly (m/d)
Medium water inflow Adjustment water inflow
1.000 yuan 0.010 yuan k
Slightly encountered water
No water avoidance
8.3.5 The water supply of aquifers should be determined by pumping test. The water supply of loose rock aquifers should be determined by laboratory method. The water supply of rock fissures and karst can be replaced by fissure ratio and karst ratio. In experienced areas, empirical values ​​can be used. 8.3.6 The leakage coefficient should be determined by multi-hole pumping test with observation holes. The influence radius can be determined by calculation method. When the project requires, it can be obtained by actual measurement method. 8.3.7 For pore water pressure, a vertical pipe pressure gauge can be used in medium and above permeable soil layers. In weak permeability soil layers, a pore water pressure probe should be used for measurement. 8.3.8 The layout of pumping test and water injection test should comply with the following provisions: 1. The test holes should be arranged in different geomorphic units, different aquifers (groups) and in areas with strong water richness, and should be 3 to 5 meters away from the outside of the tunnel. 2. The sections and stations where the groundwater level is lowered for construction. 3. Evaluate the sections where precipitation affects the environment. To evaluate the permeability of the aquifer, the observation holes of the pumping test should be vertical or parallel to the water flow direction. 5. The water level drop depth of the pumping test hole should be close to the construction precipitation state. 6. In areas with complex aquifer structures and strong water richness, pumping tests should be carried out in layers or sections: groundwater and confined water, and confined water and fresh water should be pumped separately. 8.3.9 During the pumping test and the water injection test, the water level and water volume shall be observed at the same time. 8.3.10 The pumping stability shall be determined based on the principle that the relationship curve between the water output and the water level drop and time has small fluctuations within a certain range and there is no continuous upward or downward trend. The stability duration shall not be less than 8 hours.
8.3.11 After the pumping is completed, the water level shall be restored and observed until it is stable. 8.3.12 The injection stabilization time of the water injection test should be 4~～6h8.3.13 In the sections with simple water-bearing structures and weak water-richness, the water extraction test can be used. 8.3.14 The permeability coefficient shall be calculated and determined based on the analysis of the hydrogeological conditions. When calculating the permeability coefficient based on the water level recovery rate, the calculation formula can be selected according to Appendix D of this specification.
8.4 Water sampling and test items
8.4.1 Water samples for water quality analysis should represent the objective water quality under natural conditions and meet the following requirements:
1 Groundwater samples should be collected from different aquifers in different geomorphic units. 2 The boreholes for taking water samples should be free of mud and foreign matter. 3 Glass bottles or plastic bottles with ground glass stoppers should be used as water containers, and they must be thoroughly cleaned before taking water samples.
4 The depth of water sampling should be below 0.5m above the water surface. 5 The amount of water sample collected should not be less than 750ml, of which one bottle is 250~300ml for analyzing corrosive CO)2, and 2-~3g marble powder should be added immediately. 6 After the water sample is collected, it should be sealed with wax or sealing wax immediately, and the water sample cage and sample delivery form should be filled in according to relevant regulations.
7 Water samples should be kept away from direct sunlight, and the storage time of samples should not exceed the relevant regulations.
B. 4. 2 Water quality analysis items should include: pH value, acidity, alkalinity, free CO1, slow-corroding CO,, mineralization, hardness, dissolved oxygen, conductivity, Na+, K+, Mg*+, Ca1+, Fe2+, Fe*+, NH,*, CI, SO,-, HCO,\, NO,-, CO,\-.OH- and organic matter. 8. 4. 3 The collection and analysis of water samples for special purposes should be carried out in accordance with relevant regulations. 8.5 Engineering precipitation
8. 5. 1 Engineering precipitation survey should collect local precipitation experience and relevant hydrogeological data, and should be carried out simultaneously with the survey stage.
8.5.2 The following contents shall be ascertained in the engineering dewatering survey: 1. The distribution of strata, lithology, structure, aquifers and impermeable layers, groundwater types, water quality, water volume, permeability coefficient, recharge, runoff and discharge conditions. 2. The foundation conditions of important buildings along the line, the distribution of various structures, and the distribution of natural landscapes, cultural landscapes and municipal facilities. 8.5.3 The applicable scope of dewatering methods can be selected according to Table 8.5.3. Sump open drainage
Electric drainage point
Jet drainage point
Vacuum drainage point
Large well
Radiation well
Infiltration well
Table 8.5. 3 Scope of application of precipitation methods Land use Weathered bedrock, clay soil, sand soil Clay fill, clay soil Silt, silt sand, clay soil, silt, silt sand, fine sand Sand, gravel, silty soil, gravel soil, clay soil, sand, gravel sand, clay soil, sand Infiltration coefficient (m/d) 0. 1~ 20. 0 0. 1 ~ 20. 0 1.0~200. 0 1.0200. 0
0. 1 ~ 20. 0
0. 1 ~ 20. 0
Lower water level (m)
Single-stage <6, multi-stage <20
Lead upper water to lower
aquifer
When the precipitation methods listed in Table 8.5.3 of this Code cannot meet the precipitation depth requirements, they can be used in combination with blocking, interception and other methods. 8.5.4
When precipitation is not suitable on the ground due to restrictions such as important buildings, natural landscapes or cultural landscapes on the ground, precipitation measures can be adopted in the tunnel. 8.5.6 When precipitation is carried out, the water output should be calculated. When it affects groundwater resources and ground settlement, groundwater that meets the water quality standards should be recharged to the deep ground. 8.5.7 The additional ground settlement caused by engineering precipitation can be calculated by the method in Appendix E of this Code.
8.5. 8 The calculation formula should be selected to predict the foundation water output according to the groundwater type, foundation pit shape and water-bearing structure characteristics, integrity and other conditions, and to propose a precipitation plan. 1 The block foundation pit can be simplified into a circular shape. The foundation pit water output can be calculated using the "big well method" and the calculation formula in Table 8. 5.8-1. Calculation formula for water discharge of national foundation pit
Table 8.5.8-1
Water-capable
Foundation pit (well)
Complete and
Water inflow from the bottom of the foundation pit (well)
Water inflow from the foundation pit (well)
Note 1 In the formula Q
Q= 1 366(2H- 5)5
Q=4kSro
x(H2 -h*)
Ig +(1 -0.2 years)
Water discharge of foundation pit (m/d)
Static advance coefficient (m/d);
Equivalent radius of foundation pit (m);
--Influence radius (m)
. Reference influence radius (m)
- Design water level drawdown (m)
Pressure water
Q=2ntSr.
2 yuan kMS
E+M=a+0.2
- Distance from static water level or pressure head to the bottom plate of the aquifer (m); Distance from dynamic water level to the aquifer floor (m)
. Average dynamic water level ():
Pressure water pressure thickness (m)
Thickness of water inlet section in foundation pit (m).
2R,-R+ral
C=(H+h)/2.
2 For strip foundation pits with flow direction cutting through the aquifer, the water output can be calculated by the formula in Table 8.5.8-2.
Table 8. 5. 8-2 Calculation formula for water discharge from simple foundation pit Water type
Note In the formula.
Calculation formula
Q-I4(2H-S)S+1.3686(2H-S2S
R-certificate number
Q-2AMIS+ 2. 73kMS
IgR- Ig o
Length of strip foundation pit (m),
Width of strip foundation pit (m)
For the rest, see Table 8, 5. B-1 Note,
213 ---11
8.5.9 The water yield of a single well in pipe and precipitation should be selected according to the conditions such as groundwater type and well solution arrangement, using the interference group theory to select the calculation formula. The water yield of a single well in a homogeneous unbounded aquifer and a complete group can be calculated using the formula in Table 8.5.9. Table 8. 5. . The calculation formula of single and single water output of precipitation and group is calculated
foundation (and)
groundwater
closed disturbance well group
single row straight line group
Note: Wu Ying
366 (2F7--S
single drainage discharge age (m//d);
2 yuan MS-
S.\-design precipitation and water level reduction obstacle (m); calculate the distance from the precipitation piece to the rest of the service in the group (m); (r++t+*t)
Number of precipitation wells;
Dewatering distance (m);
Dewatering sheet radius (m).
8.5.10 The dewatering water level of the pipe well can be calculated according to the nature of the aquifer and the dewatering well and the arrangement of the well group. For block foundation pits and pipe wells with the same water output, the following formula is used:! The water level drop at any point:
Submersible complete well
Pressure complete well
2 The water level drop at the center of the foundation pit:
Submersible complete well
Pressure complete well
1.366 yuan 8
S=2.73mlg
Play
XiX2-Xn
Water level drop (m):
Distance from the drop calculation point to each precipitation well (m), H..--Water level or head height before precipitation (m), (8.5. 10-1)
(8.5.10-2)
(8.5.10-3)
(8.5.10-4)
Q\--Water output of a single precipitation well (m/d). 8.5.11
, Engineering precipitation should be carried out for precipitation water level, water discharge, water quality and environment monitoring, and observation records should be kept.
9 In-situ test
9. 1 General Provisions
9.1.1 The in-situ test method shall be determined based on the project requirements, geotechnical conditions, the design needs for integers, regional experience and test methods. 9.1.2 The in-situ test shall be used in combination with indoor on-site tests and engineering experience, and a comprehensive analysis shall be conducted.
9.1.3 The in-situ test method shall comply with the provisions of the relevant test regulations. 9.2 Standard Penetration Test
9.2.1 The standard penetration test is applicable to sand, silt, clay, residual soil, fully weathered rock and strongly weathered rock.
2-13—12
9.2.2 The standard penetration test can be used for one of the following purposes: 1. To take disturbed samples, identify and describe the soil type. 2. To determine the density of sand, the bearing capacity of natural foundation soil and the deformation parameters of foundation soil. 3. To estimate the ultimate bearing capacity of a single pile and the pull-out resistance of the anchor rod, and to determine the possibility of pile sinking. 4 Determine the possibility and liquefaction grade of saturated sand and silt 9.2.3 The standard penetration test can be carried out within the full depth of the borehole or in individual soil layers at intervals of 1 to 2 m, and the residual soil at the bottom of the hole should be removed and pre-penetrated 15 cm. 9.2.4 When the number of blows within 30 cm has reached 50, forced penetration is no longer required, but the penetration depth at 50 blows should be recorded. The test results can be converted into the equivalent of 30 cm blows according to the following formula.
N=30n/AS
Where N is the measured standard blows,
the blows taken are 50;
As corresponds to the penetration depth of n cm).
9. 2. 5 The results of the standard penetration test should be statistically analyzed using the measured values ​​according to mathematical statistics. It is not appropriate to use the N value of a single hole to evaluate the engineering performance of the soil. 9.2.6 For each station and section in the same geological unit, the number of standard penetration tests for each layer shall not be less than 10.
Dynamic penetration test
9.3.1 The type of dynamic penetration (cone) test shall comply with the provisions of Table 9.3.1. Light dynamic penetration test is applicable to general clay soil and fill. Heavy dynamic penetration test and super heavy dynamic penetration test are applicable to strongly weathered and fully weathered hard rock, various soft rocks and sand, gravel (breccia) and pebbles (crushed stone). Types of dynamic penetration test
Table 9.3.1
Mass of the test piece (kg)
Diameter (mm)
Vertical angle ()
Fiber diameter (mm)
Degree of penetration (cm)
Penetration index
63.5±0.5
9.3.7 Dynamic penetration test can be used for one of the following purposes: 1. To divide soil layers and assess the uniformity and density of soil. 2. To determine the bearing capacity and deformation modulus. 3. To select the bearing layer of pile foundation and estimate the bearing capacity of single pile. 4. To test the effect of foundation reinforcement and improvement. 5. To conduct foundation pit inspection.
Super shear type
100±2
9.3.3 Dynamic penetration test should be combined with regional experience and used in conjunction with other methods. 9.3. 4 Single-hole dynamic penetration test can draw dynamic penetration hit count and depth curve or dynamic penetration resistance and depth curve to conduct mechanical stratification. It is not appropriate to use single-hole hit count to evaluate the engineering performance of soil.
9.3.5 For each station and section in the same geological unit, the number of dynamic melting test for each layer should not be less than 10.
9.4 Pressure test
9.4.1 Pressure test is applicable to clay, silt, sand, gravel, soft rock and weathered rock.
9. 4. 2 Pressure test can be used for one of the following purposes: To determine the critical plastic pressure and ultimate pressure of soil to assess the bearing capacity of foundation soil. The self-drilling lateral pressure test can determine the in-situ horizontal stress or static lateral pressure coefficient of the soil 2
:
3 and estimate the lateral pressure modulus, lateral pressure shear modulus and horizontal base bed coefficient of the soil.1 The in-situ test method should be determined based on the project requirements, geotechnical conditions, the need for integers in the design, regional experience and test methods. 9.1.2 The in-situ test should be used in combination with indoor on-site tests and engineering experience, and a comprehensive analysis should be conducted.
9.1.3 The in-situ test method should comply with the provisions of the relevant test regulations. 9.2 Standard penetration test
9.2.1 The standard penetration test is applicable to sand, silt, clay, residual soil, fully weathered rock and strongly weathered rock.
2-13—12
9.2.2 The standard penetration test can be used for one of the following purposes: 1. Take disturbed samples to identify and describe the type of soil. 2. Determine the density of sand, the bearing capacity of natural foundation soil and the deformation parameters of foundation soil. 3. Estimate the ultimate bearing capacity of a single pile and the pull-out resistance of the anchor rod to determine the possibility of pile sinking. 4 Determine the possibility and liquefaction grade of saturated sand and silt 9.2.3 The standard penetration test can be carried out within the full depth of the borehole or in individual soil layers at intervals of 1 to 2 m, and the residual soil at the bottom of the hole should be removed and pre-penetrated 15 cm. 9.2.4 When the number of blows within 30 cm has reached 50, forced penetration is no longer required, but the penetration depth at 50 blows should be recorded. The test results can be converted into the equivalent of 30 cm blows according to the following formula.
N=30n/AS
Where N is the measured standard blows,
the blows taken are 50;
As corresponds to the penetration depth of n cm).
9. 2. 5 The results of the standard penetration test should be statistically analyzed using the measured values ​​according to mathematical statistics. It is not appropriate to use the N value of a single hole to evaluate the engineering performance of the soil. 9.2.6 For each station and section in the same geological unit, the number of standard penetration tests for each layer shall not be less than 10.
Dynamic penetration test
9.3.1 The type of dynamic penetration (cone) test shall comply with the provisions of Table 9.3.1. Light dynamic penetration test is applicable to general clay soil and fill. Heavy dynamic penetration test and super heavy dynamic penetration test are applicable to strongly weathered and fully weathered hard rock, various soft rocks and sand, gravel (breccia) and pebbles (crushed stone). Types of dynamic penetration test
Table 9.3.1
Mass of the test piece (kg)
Diameter (mm)
Vertical angle ()
Fiber diameter (mm)
Degree of penetration (cm)
Penetration index
63.5±0.5
9.3.7 Dynamic penetration test can be used for one of the following purposes: 1. To divide soil layers and assess the uniformity and density of soil. 2. To determine the bearing capacity and deformation modulus. 3. To select the bearing layer of pile foundation and estimate the bearing capacity of single pile. 4. To test the effect of foundation reinforcement and improvement. 5. To conduct foundation pit inspection.
Super shear type
100±2
9.3.3 Dynamic penetration test should be combined with regional experience and used in conjunction with other methods. 9.3. 4 Single-hole dynamic penetration test can draw dynamic penetration hit count and depth curve or dynamic penetration resistance and depth curve to conduct mechanical stratification. It is not appropriate to use single-hole hit count to evaluate the engineering performance of soil.
9.3.5 For each station and section in the same geological unit, the number of dynamic melting test for each layer should not be less than 10.
9.4 Pressure test
9.4.1 Pressure test is applicable to clay, silt, sand, gravel, soft rock and weathered rock.
9. 4. 2 Pressure test can be used for one of the following purposes: To determine the critical plastic pressure and ultimate pressure of soil to assess the bearing capacity of foundation soil. The self-drilling lateral pressure test can determine the in-situ horizontal stress or static lateral pressure coefficient of the soil 2
:
3 and estimate the lateral pressure modulus, lateral pressure shear modulus and horizontal base bed coefficient of the soil.1 The in-situ test method should be determined based on the project requirements, geotechnical conditions, the need for integers in the design, regional experience and test methods. 9.1.2 The in-situ test should be used in combination with indoor on-site tests and engineering experience, and a comprehensive analysis should be conducted.
9.1.3 The in-situ test method should comply with the provisions of the relevant test regulations. 9.2 Standard penetration test
9.2.1 The standard penetration test is applicable to sand, silt, clay, residual soil, fully weathered rock and strongly weathered rock.
2-13—12
9.2.2 The standard penetration test can be used for one of the following purposes: 1. Take disturbed samples to identify and describe the type of soil. 2. Determine the density of sand, the bearing capacity of natural foundation soil and the deformation parameters of foundation soil. 3. Estimate the ultimate bearing capacity of a single pile and the pull-out resistance of the anchor rod to determine the possibility of pile sinking. 4 Determine the possibility and liquefaction grade of saturated sand and silt 9.2.3 The standard penetration test can be carried out within the full depth of the borehole or in individual soil layers at intervals of 1 to 2 m, and the residual soil at the bottom of the hole should be removed and pre-penetrated 15 cm. 9.2.4 When the number of blows within 30 cm has reached 50, forced penetration is no longer required, but the penetration depth at 50 blows should be recorded. The test results can be converted into the equivalent of 30 cm blows according to the following formula.
N=30n/AS
Where N is the measured standard blows,
the blows taken are 50;
As corresponds to the penetration depth of n cm).
9. 2. 5 The results of the standard penetration test should be statistically analyzed using the measured values ​​according to mathematical statistics. It is not appropriate to use the N value of a single hole to evaluate the engineering performance of the soil. 9.2.6 For each station and section in the same geological unit, the number of standard penetration tests for each layer shall not be less than 10.
Dynamic penetration test
9.3.1 The type of dynamic penetration (cone) test shall comply with the provisions of Table 9.3.1. Light dynamic penetration test is applicable to general clay soil and fill. Heavy dynamic penetration test and super heavy dynamic penetration test are applicable to strongly weathered and fully weathered hard rock, various soft rocks and sand, gravel (breccia) and pebbles (crushed stone). Types of dynamic penetration test
Table 9.3.1
Mass of the test piece (kg)
Diameter (mm)
Vertical angle ()
Fiber diameter (mm)
Degree of penetration (cm)
Penetration index
63.5±0.5
9.3.7 Dynamic penetration test can be used for one of the following purposes: 1. To divide soil layers and assess the uniformity and density of soil. 2. To determine the bearing capacity and deformation modulus. 3. To select the bearing layer of pile foundation and estimate the bearing capacity of single pile. 4. To test the effect of foundation reinforcement and improvement. 5. To conduct foundation pit inspection.
Super shear type
100±2
9.3.3 Dynamic penetration test should be combined with regional experience and used in conjunction with other methods. 9.3. 4 Single-hole dynamic penetration test can draw dynamic penetration hit count and depth curve or dynamic penetration resistance and depth curve to conduct mechanical stratification. It is not appropriate to use single-hole hit count to evaluate the engineering performance of soil.
9.3.5 For each station and section in the same geological unit, the number of dynamic melting test for each layer should not be less than 10.
9.4 Pressure test
9.4.1 Pressure test is applicable to clay, silt, sand, gravel, soft rock and weathered rock.
9. 4. 2 Pressure test can be used for one of the following purposes: To determine the critical plastic pressure and ultimate pressure of soil to assess the bearing capacity of foundation soil. The self-drilling lateral pressure test can determine the in-situ horizontal stress or static lateral pressure coefficient of the soil 2
:
3 and estimate the lateral pressure modulus, lateral pressure shear modulus and horizontal base bed coefficient of the soil.
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