CJJ 10-1986 Specification for design, construction and acceptance of water supply wells
Some standard content:
Ministry of Urban and Rural Construction and Environmental Protection of the People's Republic of China Ministry of Design, Construction and Acceptance Specifications for Water Supply Pipe Wells CJ 10-86 Editing Unit: China Municipal Engineering Southwest Design Institute Approving Department: Ministry of Urban and Rural Construction and Environmental Protection of the People's Republic of China Implementation Date: December 1, 1986 Notice on Approval of Issuance of "Specifications for Design, Construction and Acceptance of Water Supply Pipe Wells" (86) Chengcheng No. 236 According to the arrangement of the former State Administration of Urban Construction (80) Chengke No. 51, the "Specifications for Design, Construction and Acceptance of Water Supply Pipe Wells" organized and compiled by China Municipal Engineering Southwest Design Institute has been reviewed by our ministry and approved as a ministerial standard with the number CJJ10-86,918. It will be implemented on December 1, 1986. During the implementation process, if you have any questions or comments, please inform the Management Group of the "Design, Construction and Acceptance Specifications for Water Supply Pipe Wells" of China Municipal Engineering Southwest Design Institute in Caojiaxiang, Waibei, Chengdu.
Ministry of Urban and Rural Construction and Environmental Protection
May 12, 1986
Chapter I General Provisions
Article 1.0.1 This specification applies to the design, construction and acceptance of water supply pipe wells for drinking and industrial production. Article 1.0.2 The design and construction of water supply pipe wells should be carried out after the necessary hydrogeological data are available. When the hydrogeological data cannot meet the design and construction of water supply pipe wells, they should be designed and constructed according to the exploration and mining wells.
Article 1.0.3 The materials used in water supply pipe wells should comply with the relevant provisions of this specification and the current standards. Chapter II
Pipe Well Design
Section I Site Survey
Article 2.1.1 Before designing, relevant data on the well construction area should be collected and studied according to the task requirements. Article 2.1.2 During the on-site survey, the groundwater development and utilization of the well construction area and the construction conditions should be understood, and the existing data should be verified.
Section 2 Well Group Layout and Well Location Determination
Article 2.2.1 The following factors should be considered in determining the location of the well group (well location):
1. Water demand and water quality requirements;
2. Reliable groundwater resources;
3. Urban planning and existing water supply facilities;
4. Convenient construction, operation and maintenance;
5. Sufficient sanitary protection range;
6. Possibility of expansion when water demand increases. Article 2.2.2 The layout of the well group should be subject to hydrogeological calculations and determined after technical and economic comparisons. When encountering thick aquifers or multi-layer aquifers with sufficient groundwater recharge sources, segmented or layered water extraction well groups can be designed; for aquifers with good connectivity to rivers, riverside well groups can be designed; when groundwater is particularly rich in karst areas, well groups at the same depth can be designed.
Article 2.2.3 When designing a well group, long-term observation holes should be set up. The design of observation holes should comply with the relevant provisions of the "Specifications for Hydrogeological Exploration for Water Supply" (TJ27--78). Article 2.2.4 When designing a well group, spare wells should be set up. The number of spare wells can be determined based on the number of production wells that can still meet the design water volume when 10-20% of the production wells stop working. But it must not be less than one. Article 2.2.5 Adequate safety distance should be maintained between the well group and tall buildings or important structures.
Section 3 Pipe Well Structure Design
Article 2.3.1 Pipe well structure design generally includes the following contents:
1. Well structure;
2. Filter type and well pipe configuration;
3. Gravel filling specifications and location;
4. Closure location and materials used;
5. Ancillary facilities of pipe wells such as water measuring pipes and gravel filling pipes. Article 2.3.2 The well structure should be simplified as much as possible. Well design should first determine the final diameter of the well according to the well completion requirements, and then consider the well completion technology, rock drillability and other factors to determine the size and depth of each section of the well diameter, and finally determine the opening diameter of the well. Article 2.3.3 The depth of the pipe well in the loose layer should be determined according to the top plate burial depth of the aquifer (group) to be mined, the reasonable length of the filter, the installation position of the filter, and the length of the sedimentation pipe.
The pipe wells in bedrock areas should penetrate the water-bearing structural zone (karst development zone, fracture and fracture development zone) as much as possible. Note: If there is accurate information and the water-bearing structural zone is partially exposed, the pipe well may not penetrate the water-bearing structural zone. Article 2.3.4 When designing the well diameter, factors such as the designed water intake of the pipe well and the well construction technology should be considered. And meet the following requirements: 1. The diameter should be 50mm larger than the outer diameter of the designed filter. In the open hole section without filter in bedrock area, the diameter of the upper pump section should be 50mm larger than the nominal inner diameter of the well pipe marked on the nameplate of the pumping equipment. 2. The diameter of the pipe well in the loose layer should be checked with the allowable manhole seepage flow rate (,) and meet the following requirements: D
Well diameter (m);
Where D—
Q—-Designed water intake (m2 /s);
L—-Length of the working part of the filter (m);
,——Allowable manhole seepage flow rate
(m/s);
k is the permeability coefficient (m/s).
3. The final diameter of the well should be 50mm larger than the outer diameter of the sedimentation pipe. For pipe wells in bedrock areas that do not have pipes installed in the lower part, the final diameter of the pipes shall generally not be less than 150mm.
Article 2.3.5 Well pipes generally include well wall pipes, filter pipes, and sedimentation pipes. The diameter of the well pipe shall meet the following requirements: 1. The inner diameter of the well pipe in the pumping section shall be 50mm larger than the nominal inner diameter of the well pipe marked on the nameplate of the pumping equipment.
2. The outer diameter of the filter pipe shall be checked with the allowable flow rate of the pipe and meet the following requirements:
D,≥ YuanLnvg
Where D.--Outer diameter of the filter pipe (m);
Note: The wire-wrapped filter pipe is calculated to the outer surface of the wire-wrapped filter pipe. Q
-Designed water intake (m3/s);
Working part length of filter tube (m);
-Effective porosity of filter tube surface water inlet surface (-considered as 50% of the porosity of filter tube surface water inlet surface);
-Permissible in-pipe flow rate (values determined according to Table 2.3.5).
3. When drilling wells in bedrock areas, the diameter of the well pipe that has both protection and water stopping functions shall not only meet the above requirements, but also take into account the requirements of well drilling technology.
Permissible in-pipe flow rate
Permeability coefficient of aquifer k (m/d) [Permissible in-pipe flow rate u. (m/s)>122
82-122
Note: ① Gravel-filled and non-gravel-filled filters are determined according to the values in the above table. ② When groundwater may cause scaling and corrosion to the filter pipe, the permissible flow rate in the pipe should be reduced by one. Article 2.3.6 The type of pipe well filter can be determined according to the nature of the aquifer and Table 2.3.6. Table 2.3.6: Applicable filter types for different aquifers. Applicable filter types for different aquifers. Fine and silty sand aquifers. Double-layer gravel-filled filter. Single-layer gravel-filled filter. Medium sand, coarse sand, gravel. Single-layer gravel-filled filter for sand and gravel with d20 < 2 mm. Crushed soil aquifers with d20 ≥ 2 mm.
stone-soil aquifer
bedrock fissure cave
(sand-filled) aquifer
bedrock fissure cave
(non-sand-filled) aquifer
wire-wrapped filter
skeleton filter or single-layer gravel-filled filter
single-layer gravel-filled filter
skeleton filter
The skeleton of the gravel-filled filter can be perforated pipe, perforated wire-wrapped pipe or steel skeleton wire-wrapped pipe.
Article 2.3.7 Well pipes shall be installed in all pipe wells in loose layers, well wall pipes shall be installed above the design dynamic water level, filter pipes of sufficient length shall be installed in the water-intake aquifer (section) below the design dynamic water level, well wall pipes shall be installed in the remaining well sections, and sedimentation pipes shall be installed at the bottom. The length of the sedimentation pipe shall be determined according to the lithology of the aquifer and the well depth, generally 2~10m.
For pipe wells in bedrock areas, the upper pump section should be equipped with a well pipe, and whether the lower section should be equipped with a well pipe should be determined based on the stability of the rock formation. Article 2.3.8 The length and position of the filter should be determined based on the designed water output, aquifer lithology, technical and economic factors: 1. When the aquifer thickness is less than 30m, all filters can be installed in the aquifer below the designed dynamic water level; 2. When the aquifer thickness is greater than 30m, the reasonable length of the filter should be determined based on test data.
Article 2.3.9 The gravel specifications of the single-layer gravel filter can be determined according to the following provisions:
, Sandy soil aquifer when 7<10:
'Dso = (6 ~ 8)d50
(2.3.9-1)
Note: When the sandy soil aquifer is >10, some coarse particles in the sieved sample should be removed and re-sieved until n<10, and then d50 is determined according to the cumulative particle distribution curve at this time, and the filling gravel specifications are determined according to formula 2.3.9-1.
2. Gravel soil aquifer with d20<2mm: Dso = (6 ~ 8)d20
(2.3.9-2)
3. Gravel soil aquifer with d20≥2mm, the pipe well is filled with 10~20mm filling gravel or no gravel. In the formula, Ds0, dso, and d20 are the particle sizes when the cumulative percentage of sieved weight is 50% and 20% on the cumulative particle distribution curve of the filling and aquifer, respectively.
\ is the uneven coefficient of the aquifer
Fourth, gravel filling should be made of uniform gravel as much as possible (the uneven coefficient of gravel filling is less than 2).
Article 2.3.10
The wire wrapping spacing of the skeleton tube of the gravel filling filter
or the diameter of the circular hole (width of the strip hole) t of the non-wire wrapping perforated tube is generally determined by the following formula:
where D is the effective particle size of the gravel filling (mm). (2.3.10)
Article 2.3.11 The outer layer gravel filling specifications of the double-layer gravel filling filter shall be determined in accordance with the provisions of Article 2.3.9. The particle size of the inner layer gravel filling is generally 4 to 6 times the particle size of the outer layer gravel filling.
Article 2.3.12 Gravel thickness of single-layer gravel filter: 75mm for strata above coarse sand; 100mm for medium, fine and silt sand strata
Gravel thickness of double-layer gravel filter: 30-50mm for inner layer and 100mm for outer layer.
Article 2.3.13 Four spring steel plates or other protective cage devices shall be provided at the upper and lower ends of the inner gravel cage of double-layer gravel filter.
Gravel height of gravel filter shall be determined according to the following provisions in general
Articles 2, 3 and 14
1. Gravel height shall be determined according to the position of filter tube, the bottom shall be more than 2m lower than the lower end of filter tube, and the upper part shall be more than 8m higher than the upper end of filter tube. However, for pipe wells for drinking water, this restriction shall not apply when the first aquifer is too close to the ground surface. 2. When two layers of a heterogeneous aquifer or a multi-layer aquifer are close and have different particle compositions, and cannot meet the requirements of the first paragraph of this article, the following provisions may be applied according to the specific circumstances: 1. When the particle composition of the aquifer is not very different, it may be filled with gravel determined based on the fine-grained aquifer in accordance with the provisions of the first paragraph of this article.
2. When the particle composition of the aquifer is very different and it is necessary to fill gravel in layers, no matter whether the fine-grained aquifer is above or below, the gravel position of the fine-grained aquifer should be as low as possible, with the lower part being more than 2m lower than the fine-grained aquifer and the upper part being more than 8m higher than the fine-grained aquifer.
Article 2.3.15 The pore size of the skeleton filter is generally determined according to the shape of the pores and the particle composition of the aquifer in accordance with the following provisions:
Circular hole diameter t=（34）d2
Strip hole width t=（1.5～2）d2
Strip hole length L=（8～10）t
(2.3.15-1)
(2.3.15-2)
(2.3.15-3)
Note: If the value calculated according to the above formula is large, it can be appropriately reduced. Generally, the circular hole diameter is not greater than 21mm, and the strip hole width is not greater than 10mm.
The closure of the pipe well shall be designed according to the following provisions
Article 2.3.16
1. The closure of the upper part of the well pipe is generally sealed with high-quality clay balls or cement slurry, and the thickness shall not be less than 5m; 2. For aquifers with poor water quality, the liquid dispersion layer is sealed with clay balls, and the bedrock is sealed with cement slurry. The sealing position is generally 5m above and below the intended sealing layer;
3. When the pipe well exposes multiple aquifers and needs to be mined in layers, clay balls or cement slurry can be used to seal the non-mined aquifers according to their lithology and water head.
Article 2.3.17 The water measuring pipe of the pipe well in the loose layer can be designed according to the following provisions:
1. The inner diameter of the water measuring pipe is generally 38-50mm; 2. The length of the lower water inlet part is 2-3m; 3. The water pipe should be close to the well wall.
Section 4 Well Pipe Design
Article 2.4.1 The pipe material of the water supply well shall be selected according to the purpose of the well water, the quality of the groundwater, the strength of the pipe material, and technical and economic factors.
In areas where the groundwater is highly corrosive
Article 2.4.2
When designing the well pipe, the following measures shall be taken: 1. Select corrosion-resistant pipe materials, and take anti-corrosion measures for pipe materials with poor corrosion resistance;
2. When conditions permit, use filter pipes without wire wrapping; 3. Use stainless steel wire, copper wire or glass fiber reinforced polyethylene filter wire for wire wrapping.
Article 2.4.3
The quality of the pipe materials of commonly used well pipes shall meet the following requirements:
1. Steel pipe:
1. Seamless steel pipe: The curvature shall not exceed 1.5mm/m, and the wall thickness tolerance is +12.5%.
Outer diameter tolerance
The two ends of the steel pipe should be cut into right angles and burrs should be removed. There should be no cracks, folds, rolling, delamination, hairline and scar defects on the inner and outer surfaces of the steel pipe.
2. Welded steel pipe: refer to the quality requirements of seamless steel pipe. 3. The wall thickness of the steel pipe shall not be less than 8mm.
2. Cast iron pipe: The curvature shall not be greater than the provisions of Table 2.4.3.
The negative deviation of the wall thickness of the pipe body is (1+0.05T) mm. T is the standard wall thickness (mm). The length deviation is -20mm. There are no obvious defects such as cold shut, cracks, dislocation, etc. on the inner and outer surfaces of the pipe that hinder its use. The depth of various local defects that reduce the wall thickness shall not exceed (2+0.05T) mm. The end face of the pipe should be perpendicular to the axis.
3. Reinforced concrete pipe: The curvature shall not exceed 3mm/m, the outer diameter tolerance shall not exceed ±5mm, and the wall thickness deviation shall not exceed ±2mm. The inner wall shall be smooth, the pipe body shall be free of cracks, defects and hidden injuries, and the steel bars shall not be exposed. The two ends of the pipe shall be cut into right angles and burrs shall be removed.
Curvature of cast iron pipe
Nominal diameter (mm)
≤150
200~450
≥500
Degree of curvature (mm)
In the table, L represents the effective length of the pipe in meters. Article 2.4.4 When the skeleton of the wire-wrapped filter tube is a perforated tube, the shape, size and arrangement of the perforations shall be determined based on factors such as the strength of the pipe and the processing technology.
Article 2.4.5 When the skeleton of the wire-wrapped filter tube is a perforated tube, its perforation porosity shall be determined according to the strength of the tube, the stress conditions and the designed water output, and is generally 15-30%. Article 2.4.6 The wire-wrapped filter tube must have longitudinal padding. The padding height is generally 6-8mm, and the spacing is based on ensuring that the wire is 2-4mm away from the tube wall. There should be retaining hoops at both ends of the ribs. Article 2.4.7 The wire wrapping should be made of non-toxic, corrosion-resistant, high tensile strength and small expansion coefficient wire, and the cross-sectional shape should be trapezoidal or...angled.
Article 2.4.8
The wire wrapping shall not be loose. The wire wrapping spacing deviation
should be less than 20% of the designed wire spacing.
Article 2.4.9 The steel skeleton wire wrapping filter tube shall be designed according to the material strength and stress conditions.
Article 2.4.10 The well pipe should be connected by thread or welding. 1. The lower end of the welded well pipe should be leveled by machinery, and the lower end surface should have a 45° groove.
Chapter 3 Pipe Well Construction
Section 1 Drilling
Article 3.1.1. The selection of a drilling method should comprehensively consider factors such as formation lithology, wellbore structure, and drilling technology. Generally, it is determined by referring to the following table:
Drilling method selection table
Drilling method
Main process features
Drill bit rotary cutting, grinding and crushing
Rotational crushing of rocks, and positive drilling circulation of water or mud. There are core drilling and comprehensive
drilling
Down-the-hole hammer
Reverse circulation
Applicable conditions
Loose layers of sandy soil and viscous
soil; soft
to hard bedrock
Drilling tools impact and crush rocks, and loose
rock-crushed soil
tubes are used to collect rock cuttings. There are drill bit drilling layers, well depth and extraction drilling, impact and rotary crushing of rocks, and forward circulation of flushing media. Down-the-hole hammers are divided into pneumatic and hydraulic. In rotary drilling, the flushing medium is within 200m of hard bedrock, and the rock formation is water-free or rich in water and poor in water, except for loose rocks such as pebbles and pebbles (gravel), and reverse circulation. There are three ways: pump suction, air lift, (
[jet reverse circulation
dispersed layer; bedrock
rotary drilling, use air or
atomized clean water, atomized mud, foam, aerated mud, etc. as flushing media
severe rock leakage
or drought and water-scarce areas
Article 3.1.2 If boulders or hard rock formations are encountered during drilling, which makes drilling extremely difficult, blasting can be carried out in the well. Article 3.1.3 During drilling, attention should be paid to preventing deflection, and inclination should be measured in accordance with the provisions of the "Water Supply Hydrogeological Drilling and Well Drilling Operation Procedures". If the well is deflected, it should be corrected in time. When the well depth is greater than 200ml, a drill weight gauge should be installed, a drill chain should be used, and a centralizer should be added.
Article 3.1.4 and The quality shall meet the following requirements: 1. The well body shall be round; 2. The top angle and azimuth of the well shall not change suddenly; 3. The top angle of the well body shall not be inclined by more than 1° within a well depth of 100m; for well sections with a depth of less than 100m, the top angle shall not be inclined by more than 1.5° for every 100m.
Note: During impact drilling, the top angle inclination can be converted according to the displacement of the steel rope at the well mouth.
Section 2 Wall Protection and Flushing Media
Article 3.2.1 When impact drilling in loose layers, if there is sufficient water source for drilling and the water level in the well can be kept 3 to 5m higher than the static water level, water pressure wall protection should be used.
Article 3.2.2 When drilling in loose, broken or water-sensitive formations, mud wall protection is generally used. The properties of the mud should be calculated based on the stability of the formation. It is determined by factors such as the fixed conditions, the water-richness of the aquifer and the height of the water head, the depth of the well and the construction period. When making mud, four mud indicators, namely specific gravity, sand content, viscosity and water loss, should be measured.
Article 3.2.3 When drilling in bedrock covered by loose layers, pipes can be used to protect the upper loose layer and the lower rock layer that is prone to collapse. When the wall protection pipe needs to be pulled out, the contact length of each set of wall protection pipe with the formation should be less than 40m.
Note: The wall protection pipe refers to the casing and the well pipe reserved for well completion. Article 3.2.4 The flushing medium should be reasonably selected according to factors such as the characteristics of the formation and the construction conditions. Generally, the following provisions are considered: 1. For clay and stable formations, clean water is used; 2. For loose, broken or water-sensitive formations, mud is used; 3. For leakage areas and water-scarce areas, air is used; 4. For water-rich strata and strata with serious leakage, foam should be used. Article 3.2.5 When making mud, it is advisable to use clay powder for drilling; when there is no clay powder, the clay for making mud should be selected after identification.
When the performance of the prepared mud cannot meet the drilling requirements, the mud should be treated.
Section 3 Rock (Soil) Sample Collection and Strata Cataloging Article 3.3.1 The rock (soil) samples taken during the drilling process should be able to accurately reflect the characteristics of the original strata. And the following regulations should be observed:
"Take rock and soil samples for identifying strata. In non-aquifers, take one every 3 to 5 meters; in aquifers, take one every 2 to 3 meters; when changing layers, one more should be taken. When logging, scanning photography, and downhole television are used in conjunction with the work, the number of rock (soil) samples for identifying strata can be appropriately reduced.
, Take particle analysis samples. In aquifers with a thickness greater than 4m, take one sample every 4-6m. When the thickness of the aquifer is less than 4m, take one sample. The sampling weight should not be less than the following values:
Round gravel (angular breccia)
Pebbles (crushed stone)
3. The sampling rate of bedrock cores should not be less than the following values: Complete rock formation Www.bzxZ.net
Structural fracture zone, weathering zone, karst zone
Note: When building wells in areas with more hydrogeological data, the number of samples can be appropriately reduced.
Article 3.3.2
The classification and naming of soil shall be carried out in accordance with the provisions of Appendix 1 of this specification.
Article 3.3.3 The description of soil samples and rock samples (cores) shall be carried out in accordance with the contents of Table 3.3.3.
Description of soil and rock samples (cores)
Gravel soil
Sand soil
Clay soil
Rock
Description
Name, lithology, roundness, sorting, particle size, cementation and filling (content of sand and clay)
Name, color, mineral composition, sorting, cementation and inclusions (content of clay, plant and animal remains, gravel, etc.)
Name, Color, humidity, organic matter content, plasticity and inclusions
Name, color, mineral composition, structure, structural cement, fossils, veins, inclusions, weathering degree, crack properties, crack and karst development degree and filling conditions
Article 3.3.4 During the drilling process, the water level, water temperature, flushing fluid consumption, water leakage location, head and flow rate of artesian water, well wall collapse, sand gushing and gas escape, rock layer change depth, water-bearing structure and start and end depth of karst caves should be observed and recorded.
Article 3.3.5 The soil samples and rock samples (cores) taken should be described and catalogued in a timely manner. They should be properly kept and preserved at least until the pipe well is accepted.
Section 4 Well Pipe Installation
Article 3.4.1 Before installing the well pipe, the following preparations should be made:
1. Check the roundness and depth of the well body. The well body diameter shall not be less than 20mm of the designed well diameter, and the well depth deviation shall not exceed the positive and negative two-tenths of the designed well depth;
2. For well bodies with mud wall protection, except for gravity wells, the sediment at the bottom of the well should be cleaned first, and the mud should be appropriately diluted; 3. Inspect the quality of the well pipe in accordance with the relevant provisions of Section 4, Chapter 2 of this Code. Well pipes that do not meet the requirements shall not be lowered into the well.
Article 3.4.2 The method of lowering pipes should be selected according to the depth of lowering pipes, pipe strength and drilling equipment: 1. When the deadweight (floating weight) of the well pipe does not exceed the allowable tensile strength of the well pipe and the safe load of the drilling equipment, the direct lifting pipe lowering method should be used;
2. When the deadweight (floating weight) of the well pipe exceeds the allowable tensile strength of the well pipe or the safe load of the drilling rig, the tray pipe lowering method or (and) the floating plate pipe lowering method should be used;
3. When the parallel body structure is complex or the lowering depth is too large, the multi-stage pipe lowering method should be used.
Article 3.4.3 When all parallel bodies are lowered, the parallel pipes should be sealed at the bottom; when the parallel pipes are only lowered into a part of the well body, the well pipe must be located on a variable diameter well platform in a stable rock formation; if the lower parallel section is abandoned, it should be backfilled with pebbles or crushed stones and compacted before the well pipe can be lowered.
Article 3.4.4 The well pipe should be installed in the center of the well, and the upper end should be kept horizontal. The size deviation between the well pipe and the well depth shall not exceed plus or minus 0.2% of the total length. The installation position deviation of the filter pipe shall not exceed 300mm up and down.
Article 3.4.5 When installing the well pipe with gravel filter, a center finder should be installed. The outer diameter of the center finder should be 30~50mm smaller than the well diameter; the number of center finders should be determined according to the well depth.
Section 5 Gravel Filling and Closure
Article 3.5.1 Before filling gravel, the following preparations should be made: 1. Except for the artesian well, the mud should be diluted again; 2. According to the design, the number and height of the different specifications of special stones planned to be filled in the well should be calculated, and a certain margin should be prepared.
Article 3.5.2 The quality of gravel filling shall meet the following requirements: 923
1. Screen according to the design specifications, and the gravel that does not meet the specifications shall not exceed 15%;
2. Good roundness, and crushed stone shall not be used instead; 3. Siliceous gravel is preferred.
Article 3.5.3 The gravels of different specifications filled into the well shall be screened, and the screening results shall be listed in the report. Article 3.5.4 The gravel filling method generally adopts the static water gravel filling method or the circulating water gravel filling method; if necessary, the gravel filling pipe can be lowered to send the gravel into the well.
Article 3.5.Article 5
When filling gravel, gravel should be filled evenly and continuously along the periphery of the well pipe, and the speed of filling gravel should be appropriate. The depth of gravel filling should be measured as it is filled. If gravel is found to be blocked in the middle, it should be removed in time.
Article 3.5.6 For double-layer gravel filter, the gravel in the cage should be installed on the ground and vibrated before being lowered into the well. The outer layer of gravel should be filled with gravel of the outer layer specification outside the cage and 8m above. Article 3.5.7 For pipe wells using wire-wrapped filters, if the gap outside the well pipe is large, gravel with a particle size of 10 to 20 mm should be backfilled.
Article 3.5.8 Clay balls or clay blocks used for sealing should be high-quality clay. The size of clay balls (blocks) is generally 20 to 30 mm. They are put in when they are half dry, and the speed of putting in should be appropriate. Article 3.5.9 Cement slurry used for sealing is generally pumped in by mud pumps or injected by cranes.
Article 3.5.10 During the drilling process, cement slurry is used for sealing. After the cement solidifies, the sealing effect should be checked. If it does not meet the requirements, it should be resealed.
Article 3.5.11 The deviation of the sealing position outside the pipe shall not exceed 300mm up and down
Section 6 Well Washing and Pumping Test
Article 3.6.1 The well washing method shall be determined based on factors such as the characteristics of the aquifer, the pipe well structure and the drilling process. Article 3.6.2 Well washing must be timely. It can be carried out by alternating or combined methods such as pistons, air compressors, water pumps, double phosphates, acids, and carbon dioxide.
Article 3.6.3 The quality of well washing shall meet the following requirements:
, when the designed pumping reduction is reached, the difference between the unit water output of the two previous and subsequent test pumpings shall be less than 10%;
2. The sand content of the well water shall comply with the provisions of the second paragraph of Article 4.0.1 of this specification.
Article 3.6.4 In order to determine the actual water output of the pipe well, a pumping test must be carried out after the well is washed.
Article 3.6.5 The number of drops in the pumping test is generally once every 924
, and the drop value is not less than the designed pumping drop. When necessary, the number of drops can be appropriately increased.
Article 3.6.6 The stable duration of the water level and water volume in the pumping test is 8 to 2 hours in bedrock areas and 48 hours in loose layer areas.
Article 3.6.7 The observation requirements of the pumping test shall be implemented in accordance with the relevant provisions of the "Specifications for Hydrogeological Exploration for Water Supply" (TJ27-78).
Section 7 Water Sampling
Article 3.7.1 Before the end of the pumping test, a sufficient number of water samples should be taken at the outlet of the water pipe according to the analysis items and sent to the relevant units for testing in a timely manner.
Article 3.7.2 Water sampling shall meet the following requirements: 1. The sampling container shall be fully washed, and the water sample bottle for bacterial testing shall be sterilized;
2. When testing water samples for unstable components, stabilizers shall be added at the same time when sampling;
, After the water sample is taken, it shall be tightly sealed and a water sample label shall be affixed.
Chapter 4 Pipe Well Acceptance
Article 4.0.1 After the completion of the pipe well, the representatives of the design, construction and user units shall accept it on site according to the following quality standards:
1. The unit water output of the pipe well is basically consistent with the designed unit water output. When the aquifer revealed by the pipe well does not conform to the design basis, it can be accepted according to the actual pumping volume;
2. After the pumping of the pipe well is stabilized, the sand content of the well water shall not exceed 2 millionths (volume ratio);
3. Aquifers exceeding the pollution index shall be tightly sealed; 4. The height of the sediment in the well shall not be greater than 5/1000 of the well depth;
5. The installation error of the well pipe shall be within the allowable value specified in Article 3.4.4 of this Code;
6. The curvature of the well body shall be within the allowable value specified in the third paragraph of Article 3.1.4 of this Code.
Article 4.0.2 During the inspection and acceptance of pipe wells, the construction unit shall provide the following information;
1. The structure and geological column diagram;
2. The particle analysis results table of rock (soil) samples and gravel filling;
3. Pumping test data;
4. Water quality analysis data;
5. Instructions for the construction and use of pipe wells.
Appendix 1 Classification and naming standards of soil
Classification and naming standards of soil
Category name
Crushed pebbles
Naming standard
Mainly round and sub-round, with particles with a diameter greater than 200mm exceeding 50% of the total amount
Mainly angular, with particles with a diameter greater than 200mm exceeding 50% of the total weight
Mainly round and sub-round, with particles with a diameter greater than 20mm exceeding 50% of the total weight
Mainly angular, with particles with a diameter greater than 20mm exceeding 50% of the total weight
Mainly round and sub-round, with particles with a diameter greater than 2mm exceeding 50% of the total weight
Clay silt
Mainly angular, with particles with a diameter greater than 2mm Particles with a diameter greater than 2 mm account for 25 to 50% of the total weight
Particles with a diameter greater than 0.5 mm account for more than 50% of the total weight
Particles with a diameter greater than 0.25 mm account for more than 50% of the total weight
Particles with a diameter greater than 0.074 mm account for more than 85% of the total weight
Particles with a diameter greater than 0.074 mm account for more than 50% of the total weight
Plasticity index I, ≤10
Plasticity index 102. During the inspection and acceptance of pipe wells, the construction unit shall provide the following information;
1. The structure and geological column diagram;
2. The particle analysis results table of rock (soil) samples and gravel filling;
3. Pumping test data;
4. Water quality analysis data;
5. Instructions for construction and use of pipe wells.
Appendix 1 Classification and naming standards of soil
Classification and naming standards of soil
Category name
Crushed pebbles
Naming standard
Mainly round and sub-round, with particles with a diameter greater than 200mm exceeding 50% of the total amount
Mainly angular, with particles with a diameter greater than 200mm exceeding 50% of the total weight
Mainly round and sub-round, with particles with a diameter greater than 20mm exceeding 50% of the total weight
Mainly angular, with particles with a diameter greater than 20mm exceeding 50% of the total weight
Mainly round and sub-round, with particles with a diameter greater than 2mm exceeding 50% of the total weight
Clay silt
Mainly angular, with particles with a diameter greater than 2mm Particles with a diameter greater than 2 mm account for 25 to 50% of the total weight
Particles with a diameter greater than 0.5 mm account for more than 50% of the total weight
Particles with a diameter greater than 0.25 mm account for more than 50% of the total weight
Particles with a diameter greater than 0.074 mm account for more than 85% of the total weight
Particles with a diameter greater than 0.074 mm account for more than 50% of the total weight
Plasticity index I, ≤10
Plasticity index 102. During the inspection and acceptance of pipe wells, the construction unit shall provide the following information;
1. The structure and geological column diagram;
2. The particle analysis results table of rock (soil) samples and gravel filling;
3. Pumping test data;
4. Water quality analysis data;
5. Instructions for construction and use of pipe wells.
Appendix 1 Classification and naming standards of soil
Classification and naming standards of soil
Category name
Crushed pebbles
Naming standard
Mainly round and sub-round, with particles with a diameter greater than 200mm exceeding 50% of the total amount
Mainly angular, with particles with a diameter greater than 200mm exceeding 50% of the total weight
Mainly round and sub-round, with particles with a diameter greater than 20mm exceeding 50% of the total weight
Mainly angular, with particles with a diameter greater than 20mm exceeding 50% of the total weight
Mainly round and sub-round, with particles with a diameter greater than 2mm exceeding 50% of the total weight
Clay silt
Mainly angular, with particles with a diameter greater than 2mm Particles with a diameter greater than 2 mm account for 25 to 50% of the total weight
Particles with a diameter greater than 0.5 mm account for more than 50% of the total weight
Particles with a diameter greater than 0.25 mm account for more than 50% of the total weight
Particles with a diameter greater than 0.074 mm account for more than 85% of the total weight
Particles with a diameter greater than 0.074 mm account for more than 50% of the total weight
Plasticity index I, ≤10
Plasticity index 1017
Note: The naming of gravel soil and sandy soil should be based on the content of the particle group from large to small, and the one that meets the requirements first should be determined.
Appendix II Explanation of Standardized Words
1. Words that indicate that it is very strict and must be done: positive words use "must" and negative words use "strictly prohibited". 2. Words that indicate that it is strict and should be done under normal circumstances:
positive words use "should" and negative words use "should not" or "must not".
3. Words that indicate that there is a slight choice and that it should be done first when conditions permit:
positive words use "should" or "may" and negative words use "should not".
Additional Notes
List of the editorial unit, participating units
and main drafters of this specification
Editorial unit: China Municipal Engineering Southwest Design Institute Participating units: China Municipal Engineering Northwest Design Institute Shanxi Provincial Survey Institute
Hebei Provincial Urban Survey Company
Shandong Provincial Survey Company
Inner Mongolia Autonomous Region Hydrogeological Survey Team
Main drafters: Jiang Hongyuan, Zhang Xifan, Shen Zhenggen, Gao Hongyi, Li Xu, Rao Yaoguang, Xu Qin, Li Xu Sheng
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