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National Standard of the People's Republic of China
50218—94
Standard for engineering classification of rock masses
Standard for engineering classification of rock massesConstruction standard
1994—11—05Release
1995—07—01Implementation
State Bureau of Technical Supervision
Jointly issued
Ministry of Construction of the People's Republic of China
Engineering construction standards full-text information system
Engineering construction standards full-text information system
National Standard of the People's Republic of China
Standard for engineering classification of rock masses
Standard for engineering classification of rock massesGB50218—94
Editor department: Ministry of Water Resources of the People's Republic of ChinaApproval department: Ministry of Construction of the People's Republic of ChinaEffective date: July 1, 1995
Engineering Construction Standards Full Text Information System
Engineering Construction Standards Full Text Information System
Notice on the release of the national standard "Engineering Rock Mass Classification Standard"
Jianbiao [1994] No. 673
According to the requirements of the State Planning Commission's Document No. Jizong [1986] 450, the national standard "Engineering Rock Mass Classification Standard" edited by the Ministry of Water Resources and jointly formulated with relevant departments has been reviewed by relevant departments. The "Engineering Rock Mass Classification Standard" GB50218-94 is now approved as a mandatory national standard and will be implemented from July 1, 1995. The Ministry of Water Resources is responsible for the management of this standard, and the Ministry of Water Resources Yangtze River Scientific Research Institute is responsible for its specific interpretation, and the Ministry of Construction Standards and Quotas Institute is responsible for its publication and distribution. Ministry of Construction of the People's Republic of China
November 5, 1994
Engineering Construction Standards Full-text Information System
Engineering Construction Standards Full-text Information System
2 Terms and symbols
3 Factors for classification of basic rock mass quality
3.1 Classification factors and their determination methods
3.2 Qualitative classification of rock hardness
3.3 Qualitative classification of rock mass integrity
3.4 Determination and classification of quantitative indicators
4 Classification of basic rock mass quality
4.1 Determination of basic quality level
Qualitative classification of basic quality Characteristics and basic quality indicators Determination of engineering rock mass grade
General provisions....
Determination of engineering rock mass grade
Appendix A
Appendix B
Provisions for KJ test
Evaluation of initial stress field of rock mass
Appendix C Physical and mechanical parameters of rock mass and structural surface Appendix D
Appendix E
Appendix F
Correction of basic quality indicators of rock mass
Self-stabilizing capacity of rock mass for underground engineering
Explanation of terms used in this standard
Additional notes
Engineering Construction Standards Full-text Information System
. (11)
Engineering Construction Standards Full-text Information System
1 This standard is formulated in order to establish a unified classification method for evaluating the stability of engineering rock mass and to provide the necessary basic basis for the investigation, design, construction and quota compilation of rock engineering construction.
2This standard applies to the rock mass classification of various types of rock engineering. 1.0.3
Engineering rock mass classification shall adopt a combination of qualitative and quantitative methods and be carried out in two steps: first determine the basic quality of the rock mass, and then determine the rock mass level in combination with the characteristics of the specific project.
1.0.4 The geological survey and rock test required for engineering rock mass classification shall comply with the provisions of relevant current national standards in addition to complying with this standard. Engineering Construction Standards Full-text Information System
Engineering Construction Standards Full-text Information System
2Terms and Symbols
2.1.1 Rock engineeringrock engineering is an engineering project that uses rock mass as the foundation or environment of engineering buildings and excavates or reinforces rock mass, including underground engineering and ground engineering. 2Engineering rock massengineeringrockmass2.1.2
Rock mass within the scope of influence of rock engineering, including underground engineering rock mass, industrial and civil building foundations, dam bedrock, slope rock mass, etc. 2.1.3 Basic quality of rock mass rock mass basic quality The most basic property inherent in rock mass that affects the stability of engineering rock mass. The basic quality of rock mass is determined by the hardness and integrity of rock mass. 2.1.4 Structural plane (discontinuity) The cracked and crack-prone surface in rock mass, such as layer, joint, fault, foliation, etc., also known as discontinuity surface.
2.1.5 Rock mass integrity index (K) (rock mass velocity index) Intactness index of rock mass (velocity index of rock mass) The square of the ratio of the elastic longitudinal wave velocity of rock mass to the elastic longitudinal wave velocity of rock. 2.1.6 Volumetric joint count of rock mass (J.) Volumetric joint count of rock mass
The number of joints (structural planes) within the volume of a single rock mass. 2.1.7 Point load strength index (Is (50)) Point load strength index The point load strength of a cylindrical specimen with a diameter of 50 mm when radially pressurized. 2.1.8 Stand-up time of rock mass for underground excavation
Under unsupported conditions, the ability of underground engineering rock mass to not produce any form of damage. Engineering Construction Standard Full-text Information System
Engineering Construction Standard Full-text Information System
Initial stress field
initial stress field
Under natural conditions, the stress field formed in the rock mass due to its own weight and tectonic movement is also called natural stress field.
Rock gravity density
Saturated uniaxial compressive strength of rock
Ies(s0)
Point load intensity index of rock
Deformation modulus of rock mass
Poisson's ratio of rock mass
Internal friction angle of rock mass or structural surface
Cohesion of rock mass or structural surface
Rock integrity index
Number of volume joints of rock mass
Correction coefficient of groundwater effect
Correction coefficient of influence of main weak structural surface initial stress Formation influence correction factor
Basic value of bedrock bearing capacity
Bedrock morphology influence reduction factor
Basic rock mass quality index
Correction value of basic rock mass quality index
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Engineering construction standard full-text information system
Classification factors of basic rock mass quality
3.1: Classification factors and determination methods
The basic quality of rock mass should be determined by two factors: rock hardness and rock integrity.
2 Rock hardness and rock integrity should be determined by qualitative classification and quantitative index methods.
3.2 Qualitative classification of rock hardness
Rock hardness should be qualitatively classified according to Table 3.2.1. Qualitative classification of rock hardness
Hard rock
Qualitative identification
Hammer makes a crisp sound, has rebound,
shakes the hand, and is difficult to break;
After soaking in water, most of them have no water absorption
Hammer makes a crisp sound, has slight
rebound, slightly shakes the hand, and is more difficult to break
Hard rock breaks;
After soaking in water, there is slight water absorption
Engineering Construction Standard Full-text Information System
Representative rocks
Low weathering to slightly weathered;
Granite, syenite, diorite, diabase, basalt, andesite, gneiss, quartz schist, siliceous slate, quartzite, siliceous cemented conglomerate, quartz sandstone, siliceous limestone, etc.
1. Weakly weathered hard rock;
2.Unweathered and slightly weathered;
Full text information system of engineering construction standards for welded tuff, marble, slate, dolomite, limestone, calcareous cemented sandstone, etc.
Qualitative identification
Hammer sound is not crisp, chest rebounds
, easier to break;
Softer rock
After soaking in water, nails can carve marks
Hammer sound is crisp, no rebound, there are
rock indentations, easy to break;
After soaking in water, hands can be opened
Hammer sound is cracking, no rebound, there are
|The extremely soft rock has deep dents and can be crushed by hand;
After soaking in water, it can be crushed into a ball
Representative rocks
1. Strongly weathered hard rock,
2. Weakly weathered relatively hard rock;
3. Unweathered to slightly weathered;
Continued Table 3.2.1
Tuff, phyllite, sandy mudstone, marl, argillaceous sandstone, siltstone, shale, etc. 1. Weakly weathered hard rock,
2. Unweathered to strongly weathered relatively hard rock; 3. Weakly weathered relatively soft rock;
4. Unweathered mudstone, etc.
1. Various fully weathered rocks;
2. Various semi-formed rocks
When the rock hardness is qualitatively divided, its weathering degree should be determined according to Table 3.2.2. Classification of rock weathering degree
Unweathered
Slightly weathered
Weakly weathered
Strongly weathered
Fully weathered
Weathering characteristics
The structure and texture have not changed, and the rock is fresh
The structure and texture, mineral color have basically not changed, and some fracture surfaces are stained with iron and manganese slag The structure is partially destroyed, the mineral color changes significantly, weathered minerals or weathering interlayers appear on the fracture surface
The structure is mostly destroyed, the mineral color changes significantly, and feldspar, mica, etc. are mostly weathered into secondary minerals
The structure is completely destroyed, and most of the mineral components, except quartz, are weathered into soil-like Engineering Construction Standard Full-text Information System
Engineering Construction Standard Full-text Information System
3.3 Qualitative classification of rock mass integrity
The rock mass integrity should be qualitatively classified according to Table 3.3.1. 3.3.1 Qualitative classification of rock mass integrity
Development degree of structural plane
Combination degree of main structural plane
Average spacing (m)
Relatively complete
Relatively broken
Extremely broken
Very poorly combined
Good combined or
Generally combined
Poorly combined
Good combined
Generally combined
Poorly combined
Generally combined
Or poorly combined
Main Main structural surface type
Corresponding structural type
Joints, fissures, layersIntegral or thick layered structureJoints, fissures, layers
Joints, fissures,
Layers, small faults
Various types
Structural surface
Dispersed structure
Massive or thick structure
Massive structure
Fissure massive or medium-thick structure
Inlaid fragmented structure
Medium and thin layered structure
Fissure massive structure
Fragmented structure
Note: The average spacing refers to the average spacing of the main structural surfaces (1 to 2 groups). 3.3.2
Determine.
Good bonding
The bonding degree of the structural surface should be classified according to the characteristics of the structural surface and the classification of the bonding degree of the structural surface in Table 3.3.2
Structural surface characteristics
Opening degree is less than 1mm, and there is no filling material;
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Engineering Construction Standard Full-text Information System
Good bonding
General bonding
Poor bonding
Very poor bonding
Structural surface characteristics
Opening degree is 1~3mm, which is siliceous or ferrous cementation, The opening is greater than 3mm, the structural surface is rough, it is siliceous cementation. The opening is 1~3mm, it is calcareous or mud cementation; the opening is greater than 3mm, the structural surface is rough, it is iron or calcareous cementation. Table 3.3.2
The opening is 1~3mm, the structural surface is straight, it is mud or mud and calcareous cementation, the opening is greater than 3mm, mostly mud or rock filling Mud filling or mud and rock filling, the filling thickness is greater than the undulation difference 3.4 Determination and classification of quantitative indicators
The quantitative indicator of rock hardness should be the uniaxial saturated compressive strength of rock (Re). R. The measured value should be used. When it is impossible to obtain the measured value, the converted value of the measured rock point load strength index (Is(50)) can also be used, and converted according to the following formula: R. =22.821g)
The corresponding relationship between the uniaxial saturated compressive strength of rock (R.) and the hardness of rock divided qualitatively can be determined according to Table 3.4.2. The corresponding relationship between R. and the hardness of rock divided qualitatively Re (MPa)
Hardness
Hard rock
Relatively hard rock
Relatively soft rock
Extremely soft rock
The quantitative index of rock mass integrity should adopt the rock mass integrity index (K). K should adopt the measured value. When there is no condition to obtain the measured value, the rock mass volume joint number (J) can also be used to determine the corresponding K and value according to Table 3.4.3. Engineering Construction Standard Full-text Information System
Engineering Construction Standard Full-text Information System
J (bars/m2)
J, and K comparison table
The corresponding relationship between the rock mass integrity index (K)
and the rock mass integrity degree divided qualitatively can be determined according to Table 3.4.4.
K, and the corresponding relationship between the rock mass integrity degree divided qualitatively K
Integrity degree
Relatively complete
Relatively broken
Extremely broken
The test of quantitative indicators K, J, shall comply with the provisions of Appendix A of this standard. Engineering Construction Standard Full-text Information System1
Qualitative classification of rock mass integrity
Development degree of structural plane
Combination degree of main structural plane
Average spacing (m)
Relatively complete
Relatively broken
Extremely broken
Very poorly combined
Good combined or
Generally combined
Poorly combined
Good combined
Generally combined
Poorly combined
Generally combined
Or poorly combined
Main structural planes Type of structural plane
Corresponding structural type
Joints, fissures, layersIntegral or thick layered structureJoints, fissures, layers
Joints, fissures,
Layers, small faults
Various types
Structural plane
Dispersed structure
Massive or thick structure
Massive structure
Fissure massive or medium-thick structure
Inlaid fragmented structure
Medium and thin layered structure
Fissure massive structure
Fragmented structure
Note: The average spacing refers to the average spacing of the main structural planes (1 to 2 groups). 3.3.2
Determine.
Good bonding
The bonding degree of the structural surface should be classified according to the characteristics of the structural surface and the classification of the bonding degree of the structural surface in Table 3.3.2
Structural surface characteristics
Opening degree is less than 1mm, and there is no filling material;
Engineering 6 Construction Standard Full-text Information System
Engineering Construction Standard Full-text Information System
Good bonding
General bonding
Poor bonding
Very poor bonding
Structural surface characteristics
Opening degree is 1~3mm, which is siliceous or ferrous cementation, The opening is greater than 3mm, the structural surface is rough, it is siliceous cementation. The opening is 1~3mm, it is calcareous or mud cementation; the opening is greater than 3mm, the structural surface is rough, it is iron or calcareous cementation. Table 3.3.2
The opening is 1~3mm, the structural surface is straight, it is mud or mud and calcareous cementation, the opening is greater than 3mm, mostly mud or rock filling Mud filling or mud and rock filling, the filling thickness is greater than the undulation difference 3.4 Determination and classification of quantitative indicators
The quantitative indicator of rock hardness should be the uniaxial saturated compressive strength of rock (Re). R. The measured value should be used. When it is impossible to obtain the measured value, the converted value of the measured rock point load strength index (Is(50)) can also be used, and converted according to the following formula: R. =22.821g)
The corresponding relationship between the uniaxial saturated compressive strength of rock (R.) and the hardness of rock divided qualitatively can be determined according to Table 3.4.2. The corresponding relationship between R. and the hardness of rock divided qualitatively Re (MPa)
Hardness
Hard rock
Relatively hard rock
Relatively soft rock
Extremely soft rock
The quantitative index of rock mass integrity should adopt the rock mass integrity index (K). K should adopt the measured value. When there is no condition to obtain the measured value, the rock mass volume joint number (J) can also be used to determine the corresponding K and value according to Table 3.4.3. Engineering Construction Standard Full-text Information SystembzxZ.net
Engineering Construction Standard Full-text Information System
J (bars/m2)
J, and K comparison table
The corresponding relationship between the rock mass integrity index (K)
and the rock mass integrity degree divided qualitatively can be determined according to Table 3.4.4.
K, and the corresponding relationship between the rock mass integrity degree divided qualitatively K
Integrity degree
Relatively complete
Relatively broken
Extremely broken
The test of quantitative indicators K, J, shall comply with the provisions of Appendix A of this standard. Engineering Construction Standard Full-text Information System1
Qualitative classification of rock mass integrity
Development degree of structural plane
Combination degree of main structural plane
Average spacing (m)
Relatively complete
Relatively broken
Extremely broken
Very poorly combined
Good combined or
Generally combined
Poorly combined
Good combined
Generally combined
Poorly combined
Generally combined
Or poorly combined
Main structural planes Type of structural plane
Corresponding structural type
Joints, fissures, layersIntegral or thick layered structureJoints, fissures, layers
Joints, fissures,
Layers, small faults
Various types
Structural plane
Dispersed structure
Massive or thick structure
Massive structure
Fissure massive or medium-thick structure
Inlaid fragmented structure
Medium and thin layered structure
Fissure massive structure
Fragmented structure
Note: The average spacing refers to the average spacing of the main structural planes (1 to 2 groups). 3.3.2
Determine.
Good bonding
The bonding degree of the structural surface should be classified according to the characteristics of the structural surface and the classification of the bonding degree of the structural surface in Table 3.3.2
Structural surface characteristics
Opening degree is less than 1mm, and there is no filling material;
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Engineering Construction Standard Full-text Information System
Good bonding
General bonding
Poor bonding
Very poor bonding
Structural surface characteristics
Opening degree is 1~3mm, which is siliceous or ferrous cementation, The opening is greater than 3mm, the structural surface is rough, it is siliceous cementation. The opening is 1~3mm, it is calcareous or mud cementation; the opening is greater than 3mm, the structural surface is rough, it is iron or calcareous cementation. Table 3.3.2
The opening is 1~3mm, the structural surface is straight, it is mud or mud and calcareous cementation, the opening is greater than 3mm, mostly mud or rock filling Mud filling or mud and rock filling, the filling thickness is greater than the undulation difference 3.4 Determination and classification of quantitative indicators
The quantitative indicator of rock hardness should be the uniaxial saturated compressive strength of rock (Re). R. The measured value should be used. When it is impossible to obtain the measured value, the converted value of the measured rock point load strength index (Is(50)) can also be used, and converted according to the following formula: R. =22.821g)
The corresponding relationship between the uniaxial saturated compressive strength of rock (R.) and the hardness of rock divided qualitatively can be determined according to Table 3.4.2. The corresponding relationship between R. and the hardness of rock divided qualitatively Re (MPa)
Hardness
Hard rock
Relatively hard rock
Relatively soft rock
Extremely soft rock
The quantitative index of rock mass integrity should adopt the rock mass integrity index (K). K should adopt the measured value. When there is no condition to obtain the measured value, the rock mass volume joint number (J) can also be used to determine the corresponding K and value according to Table 3.4.3. Engineering Construction Standard Full-text Information System
Engineering Construction Standard Full-text Information System
J (bars/m2)
J, and K comparison table
The corresponding relationship between the rock mass integrity index (K)
and the rock mass integrity degree divided qualitatively can be determined according to Table 3.4.4.
K, and the corresponding relationship between the rock mass integrity degree divided qualitatively K
Integrity degree
Relatively complete
Relatively broken
Extremely broken
The test of quantitative indicators K, J, shall comply with the provisions of Appendix A of this standard. Engineering Construction Standard Full-text Information System
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