This regulation is specially formulated to unify the PY type pre-drilled lateral pressure test method and reasonably determine the parameters such as foundation bearing capacity. This regulation is applicable to the test of clay, silt, sand and reinforced wind rock with PY type pre-drilled lateral pressure meter; when other types of pre-drilled lateral pressure meter are used, the relevant provisions of this regulation can be referred to. JGJ 69-1990 PY type pre-drilled lateral pressure test regulation JGJ69-1990 Standard download decompression password: www.bzxz.net

Engineering Construction Standard Full Text Information System
Industry Standard of the People's Republic of China
PY Type Pre-drilled Side Pressure Test Procedure
JGJ69——90
1991Beijing
. Engineering Construction Standard Full Text Information System
Industry Standard of the People's Republic of China
PY Type Pre-drilled Side Pressure Test Procedure
JGF 6990
Editor: Changzhou Architectural Design Institute
Approval Department: Ministry of Construction of the People's Republic of China Effective Date: December 1, 1990
. Engineering Construction Standard Full Text Information System
Notice on the Release of the Industry Standard "PY-type Pre-drilled Side Pressure Test Procedure"
(90) Jianbiaozi No. 238
According to the requirements of the former Ministry of Urban and Rural Construction and Environmental Protection (84) Chengkezi No. 153, the "PY-type Pre-drilled Side Pressure Test Procedure" edited by Changzhou Architectural Design Institute has been reviewed by our department and is now approved as an industry standard with the number JGJ6990, which will be implemented from December 1, 1990. During the implementation process, if you have any questions or comments, please inform Changzhou Architectural Design Institute in writing.
Ministry of Construction of the People's Republic of China
May 15, 1990
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Main Symbols
Chapter 2
Chapter 3
Chapter 4
Chapter 5
Chapter 6
Appendix—
Instruments and Equipment
Test Drilling
Test Procedures
Instrument Calibration
Data Arrangement·
Principle Diagram of Pressure Gauge
Test Record Format and Engineering Examples
Terminology Used in This Code·
Additional Explanation
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Main Symbols||tt ||Original volume of the middle cavity of the pressure gauge (cm2)
-The volume of the middle cavity of the pressure gauge under pressure after correction (cm2);-The volume corresponding to each level of total pressure (pm+pw) (cm*);The intersection of the straight line segment of the pressure curve and the vertical axis, its value is the volume of water consumed by the pressure gauge in contact with the hole wall (cm3);
AV60-30
AV120-30
AS60-to
S120-30
The volume increment between the 30s reading and the 60s reading;-The volume increment between the 30s reading and the 120s reading;The volume corresponding to the critical pressure pr (cm2):The comprehensive deformation correction coefficient of the instrument (cm*/kPa, cm/kPa);The original volume V of the middle cavity of the pressure gauge. It is expressed as the drop value of the water level in the measuring tube (cm);
The volume of the pressurized expansion volume of the middle cavity of the lateral pressure gauge after correction is expressed as the drop value of the water level in the measuring tube (cm):
The drop value of the water level in the measuring tube corresponding to each level of total pressure (pm + pw) (cm);The intersection of the straight line segment of the lateral pressure curve and the vertical axis, its value is the volume of water consumed by the lateral pressure gauge contacting the hole wall, expressed as the drop value of the measured water level (cm);
The increment of the drop value of the water level in the measuring tube between the 30s reading and the 60s reading (cm);
The increment of the drop value of the water level in the measuring tube between the 30s reading and the 120s reading (cm);
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The drop value of the water level in the measuring tube corresponding to the plastic pressure pz (cm);Pressure after correction (kPa):
Stationary earth pressure (kPa);
Plastic pressure (kPa);||tt| |Ultimate pressure (kPa);
Hydrostatic pressure (kPa);
Pressure gauge reading (kPa)
Elastic membrane constraint force (kPa);
Static earth pressure coefficient;
Natural gravity density of soil (kN/m):
Gravity density of water (kN/m);
Pore water pressure of soil (kPa);
Lateral expansion coefficient of soil (Poisson's ratio);|| tt||Test depth (m):
Depth of the ground from the groundwater level;
Standard value of foundation bearing capacity (kPa);
Side pressure modulus (MPa);
Compression modulus (MPa);
Deformation modulus (MPa);
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Chapter 1 GeneralwwW.bzxz.Net
Article 1.0.1 is to unify the PY type pre-drilled side pressure test method. This regulation is specially formulated to reasonably determine parameters such as foundation bearing capacity. Article 1.0.2 This regulation is applicable to the testing of clay
silt, sand and reinforced rock with PY type pre-drilled piezometer. When other types of pre-drilled piezometers are used, the relevant provisions of this regulation may be referred to. Article 1.0.3 When adopting this regulation, the relevant provisions of the current national standard "Geotechnical Engineering Investigation Code" shall also be complied with.Engineering Construction Standard Full Text Information System
Chapter 2 Instruments and Equipment
Article 2.0.1 The piezometer consists of a piezometer, a pressure-stabilizing device, and a measuring device (see Appendix 1, Figures 1-1 and 1-2), and is equipped with test drilling tools
, piezometer: a three-chamber cylindrical structure with an elastic membrane on the outer cover, an outer diameter of 50mm (55mm with a full metal protective cover). The total length of the three chambers is 450mm, the middle chamber is the test chamber, 250mm long, and the volume V. =491cm3 (594cm with a metal protective cover); the upper and lower chambers are protective chambers, each 100mm long, and the upper and lower chambers are connected by a copper conduit and isolated from the middle chamber. The central axis of the three chambers is a water pipe, which is used to drain groundwater so that the piezometer can be smoothly placed at the test depth
Pressure-stabilizing device: the pressure source is high-pressure nitrogen or artificial air pumping, and a pressure gauge is attached. Pressure regulating valves are used for pressure increase and stabilization. 1. Measuring device: The corresponding deformation value of the soil body of the hole wall after being compressed is measured by a measuring tube or a liquid level meter.
4. Test drilling tools: spoon drill, soil lifter and mud pump, etc. bzSoO, co玛Engineering Construction Standard Full Text Information System
Chapter 3 Test Drilling
Article 3.0.1 The test drilling operation shall meet the following requirements: 1. The diameter of the drill hole is 2 to 6 mm larger than the outer diameter of the pressure gauge. The hole diameter should not be too large for the soil layer with good stability on the hole wall;
2. Reduce the disturbance of the soil body of the hole wall;
Protect the natural water content of the soil body of the hole wall
4. The hole shape is round and the hole wall is vertical.
Article 3.0.2 It is not suitable to carry out pressure test in the following hole sections: 1. The hole section where the original soil sample has been taken or the standard penetration test has been carried out; 2. The hole section spanning the soil layers of different properties.
Article 3·0·3 The minimum test depth, the interval between continuous test depths, the spacing from the original soil drilling hole or other in-situ test holes, and the horizontal distance of the test holes should not be less than 1m.
Article 3·0·4 The drilling depth should be 50cm greater than the test depth. When drilling with a large-diameter drill, it can only be drilled to 1m above the test section, and then the hole diameter is drilled according to the requirements of the lateral pressure test.
Article 3·0·5 Different drilling tools should be used for soil layers of different properties:
For hard-plastic soil layers, a spoon-shaped drill can be used; for soft-plastic-plastic soil layers, a soil lifter can be used; for soil layers with poor stability of the borehole wall, mud wall drilling should be used.
Engineering Construction Standard Full Text Information System
Chapter 4
Test Steps
Article 4·0·1 The quick connectors of the water injection pipe and the pressure pipe of the pressure gauge should be inserted into the sockets on the measuring device.
Article 4·0·2 The water injection steps should comply with the following provisions: First fill the water tank with distilled water or clean cold boiled water; Put the pressure gauge firmly on the ground, open all valves on the water tank to the measuring pipe and auxiliary pipe, and loosen the pressure regulating valve in a counterclockwise direction; Third, add a little pressure to the water tank to speed up the water injection speed. During this process, the nylon tube bundle and the pressure gauge should be constantly tapped to remove the bubbles trapped in the pressure gauge and the pipeline;
When the water level in the measuring pipe reaches or is slightly higher than the zero position, close the water injection valve and the middle cavity water injection valve to stop water injection.
Article 4·0·3 Zero adjustment and inserting the pressure gauge. Lift the pressure gauge vertically, make the midpoint of the test cavity level with the zero scale of the measuring tube, adjust the water level to zero, and immediately close the measuring tube valve and auxiliary pipe valve, and then put the pressure gauge into the predetermined test depth of the borehole. Article 4.0.4 The pressure test method shall comply with the following provisions: 1. Open the measuring tube valve and auxiliary pipe valve. At this time, hydrostatic pressure is generated in the pressure gauge, which is the first level pressure.
Hydrostatic pressure is the pressure generated by the water column from the midpoint of the pressure gauge test chamber to the water surface of the measuring tube, calculated according to formula (4·0·4):
Pw=(H+Z)
wherein pw is the hydrostatic pressure (kPa);
is the height of the water surface of the measuring tube from the orifice (m); (4·0·4)
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is the depth of the pressure gauge test (m);
is the gravity density of water (kN/m), which can be taken as 10kN/m. 2. Choose one of the following two pressurization methods to pressurize: 1. High-pressure nitrogen pressurization: First connect the nitrogen source, close the manual pressurization valve, open the nitrogen pressurization valve, turn the pressure reducing valve on the nitrogen bottle counterclockwise to the loosest position (the output is in the closed state at this time), then open the nitrogen source gate, and press the pressure reducing valve clockwise to reduce the high pressure to 100~20kPa higher than the expected maximum test pressure, and set it aside. 2. Manual pressurization: First connect the air pump, close the nitrogen pressurization valve, open the manual pressurization valve, and use the air pump to pressurize the gas storage tank to increase the pressure of the gas storage tank to 100~200kPa higher than the expected maximum test pressure, and set it aside. When pressurizing, slowly rotate the pressure regulating valve clockwise to the required pressure, and pressurize step by step.
Article 40.5 The test pressure increment should be 1/51/7 of the estimated critical pressure Pr. If it is not easy to estimate, it can be determined according to Table 4.0.5. Test pressure increment
Soil characteristics
Mixed, muddy soil, clay in plastic state, loose powder or fine sand clay in soft plastic state, loose loess, slightly dense saturated silt, slightly dense very wet powder or fine sand, slightly dense coarse sand-hard plastic clay,
General yellow soil, medium dense
Spotted saturated silt, medium dense-dense very wet powder or fine sand, medium dense medium coarse sand
Hard plastic-hard clay, dense silt, dense medium coarse sand Table 4·0·5 ||tt| |Pressure increment (kPa)
50~100
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Article 4·0·6 The observation time under each level of pressure can be 1min or 2min according to the specific conditions such as soil characteristics, and the volume V (or the drop value of the water level in the measuring tube S) shall be measured and recorded in the following time sequence:
, when the observation time is 1min: 15s, 30s, 60s; 2. When the observation time is 2min: 15s, 30s, 60s, 120s. Article 4·0·7 Termination of the test: When the volume reading of the measuring tube reaches 600cm (the drop value of the water level in the measuring tube s is 40cm), the test shall be terminated immediately. Article 4·0·8 The following measures shall be taken according to the situation: 1. The water in the piezometer shall be returned or drained, and the elastic membrane shall be restored to its original state, so that the piezometer can be removed from the borehole smoothly. 1. When the test depth is less than 2m and the test needs to be continued, turn the pressure regulating valve counterclockwise to the loosest position to relieve the pressure of the entire pipeline and the lateral pressure device, and use the restraining force of the elastic membrane to force the water in the lateral pressure device back to the measuring pipe and the auxiliary pipe; 2. When the test depth is greater than 2m and the test needs to be continued, first open the water tank safety cover, then open the middle cavity water injection valve and the water injection valve, and use the high pressure condition in the lateral pressure device and the pipeline when the test is terminated to return the water in the lateral pressure device to the water tank, then close the water injection valve, loosen the pressure regulating valve, and relieve the pressure of the entire pipeline and the lateral pressure device; when all the water in the lateral pressure device needs to be drained, open the middle cavity water injection valve and the drain valve, and use the high pressure condition in the lateral pressure device and the pipeline when the test is terminated to drain the water in the lateral pressure device, and then loosen the pressure regulating valve to relieve the pressure of the entire pipeline and the lateral pressure device. After the pressure relief device and pipeline are depressurized, in order to restore the elastic membrane of the pressure relief device to its original state, you must wait for 2 to 3 minutes before removing the pressure relief device.Manual pressurization: First connect the air pump, close the nitrogen pressurization valve, open the manual pressurization valve, and use the air pump to pressurize the air tank to increase the pressure of the air tank to 100-200 kPa higher than the expected maximum test pressure. Keep it for standby. When pressurizing, slowly rotate the pressure regulating valve clockwise to the required pressure, and pressurize step by step.
Article 40.5 The test pressure increment should be 1/51/7 of the estimated critical pressure Pr. If it is difficult to estimate, it can be determined according to Table 4.0.5. Test pressure increment
Soil characteristics
Mixed, muddy soil, clay in plastic state, loose powder or fine sand clay in soft plastic state, loose loess, slightly dense saturated silt, slightly dense very wet powder or fine sand, slightly dense coarse sand-hard plastic clay,
General yellow soil, medium dense
Spotted saturated silt, medium dense-dense very wet powder or fine sand, medium dense medium coarse sand
Hard plastic-hard clay, dense silt, dense medium coarse sand Table 4·0·5 ||tt| |Pressure increment (kPa)
50~100
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Article 4·0·6 The observation time under each level of pressure can be 1min or 2min according to the specific conditions such as soil characteristics, and the volume V (or the drop value of the water level in the measuring tube S) shall be measured and recorded in the following time sequence:
, when the observation time is 1min: 15s, 30s, 60s; 2. When the observation time is 2min: 15s, 30s, 60s, 120s. Article 4·0·7 Termination of the test: When the volume reading of the measuring tube reaches 600cm (the drop value of the water level in the measuring tube s is 40cm), the test shall be terminated immediately. Article 4·0·8 The following measures shall be taken according to the situation: 1. The water in the piezometer shall be returned or drained, and the elastic membrane shall be restored to its original state, so that the piezometer can be removed from the borehole smoothly. 1. When the test depth is less than 2m and the test needs to be continued, turn the pressure regulating valve counterclockwise to the loosest position to relieve the pressure of the entire pipeline and the lateral pressure device, and use the restraining force of the elastic membrane to force the water in the lateral pressure device back to the measuring pipe and the auxiliary pipe; 2. When the test depth is greater than 2m and the test needs to be continued, first open the water tank safety cover, then open the middle cavity water injection valve and the water injection valve, and use the high pressure condition in the lateral pressure device and the pipeline when the test is terminated to return the water in the lateral pressure device to the water tank, then close the water injection valve, loosen the pressure regulating valve, and relieve the pressure of the entire pipeline and the lateral pressure device; when all the water in the lateral pressure device needs to be drained, open the middle cavity water injection valve and the drain valve, and use the high pressure condition in the lateral pressure device and the pipeline when the test is terminated to drain the water in the lateral pressure device, and then loosen the pressure regulating valve to relieve the pressure of the entire pipeline and the lateral pressure device. After the pressure relief device and pipeline are depressurized, in order to restore the elastic membrane of the pressure relief device to its original state, you must wait for 2 to 3 minutes before removing the pressure relief device.Manual pressurization: First connect the air pump, close the nitrogen pressurization valve, open the manual pressurization valve, and use the air pump to pressurize the air tank to increase the pressure of the air tank to 100-200 kPa higher than the expected maximum test pressure. Keep it for standby. When pressurizing, slowly rotate the pressure regulating valve clockwise to the required pressure, and pressurize step by step.
Article 40.5 The test pressure increment should be 1/51/7 of the estimated critical pressure Pr. If it is difficult to estimate, it can be determined according to Table 4.0.5. Test pressure increment
Soil characteristics
Mixed, muddy soil, clay in plastic state, loose powder or fine sand clay in soft plastic state, loose loess, slightly dense saturated silt, slightly dense very wet powder or fine sand, slightly dense coarse sand-hard plastic clay,
General yellow soil, medium dense
Spotted saturated silt, medium dense-dense very wet powder or fine sand, medium dense medium coarse sand
Hard plastic-hard clay, dense silt, dense medium coarse sand Table 4·0·5 ||tt| |Pressure increment (kPa)
50~100
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Article 4·0·6 The observation time under each level of pressure can be 1min or 2min according to the specific conditions such as soil characteristics, and the volume V (or the drop value of the water level in the measuring tube S) shall be measured and recorded in the following time sequence:
, when the observation time is 1min: 15s, 30s, 60s; 2. When the observation time is 2min: 15s, 30s, 60s, 120s. Article 4·0·7 Termination of the test: When the volume reading of the measuring tube reaches 600cm (the drop value of the water level in the measuring tube s is 40cm), the test shall be terminated immediately. Article 4·0·8 The following measures shall be taken according to the situation: 1. The water in the piezometer shall be returned or drained, and the elastic membrane shall be restored to its original state, so that the piezometer can be removed from the borehole smoothly. 1. When the test depth is less than 2m and the test needs to be continued, turn the pressure regulating valve counterclockwise to the loosest position to relieve the pressure of the entire pipeline and the lateral pressure device, and use the restraining force of the elastic membrane to force the water in the lateral pressure device back to the measuring pipe and the auxiliary pipe; 2. When the test depth is greater than 2m and the test needs to be continued, first open the water tank safety cover, then open the middle cavity water injection valve and the water injection valve, and use the high pressure condition in the lateral pressure device and the pipeline when the test is terminated to return the water in the lateral pressure device to the water tank, then close the water injection valve, loosen the pressure regulating valve, and relieve the pressure of the entire pipeline and the lateral pressure device; when all the water in the lateral pressure device needs to be drained, open the middle cavity water injection valve and the drain valve, and use the high pressure condition in the lateral pressure device and the pipeline when the test is terminated to drain the water in the lateral pressure device, and then loosen the pressure regulating valve to relieve the pressure of the entire pipeline and the lateral pressure device. After the pressure relief device and pipeline are depressurized, in order to restore the elastic membrane of the pressure relief device to its original state, you must wait for 2 to 3 minutes before removing the pressure relief device.
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