CN108426789A - Shearing test system and its test method in the hole of deep layer original position - Google Patents

Abstract

The invention discloses a deep in-situ shear test system, which includes a drilling rig, a tension-and-convergence casing core drilling tool, a casing, a mud pump, a drilling tool fishing device, a shear probe, a tie rod, and normal stress loading Measuring device, shear stress loading measuring device, dial indicator and data acquisition recorder, the drilling rig drives the casing to drill into the formation; the positioning end pipe drives the tension-convergent casing core drilling tool for drilling and sampling; Lift the tension-and-contraction casing core drilling tool away from the casing; the pull rod sends the shear probe to the predetermined test depth; the normal stress loading measurement device applies the specified normal stress to the shear probe; the shear stress measurement device is used It is used to lift the shear probe; the dial gauge measures the shear deformation of the shear probe shear test soil; the data acquisition recorder records the shear deformation and shear force that change with time during the lifting process of the shear probe. The system is simple in structure and easy to operate, and can significantly improve the quality and efficiency of shear testing in deep in-situ holes.

Description

Deep in-situ shear test system and test method

technical field

The invention belongs to the field of geotechnical engineering in-situ testing, in particular to a deep in-situ shear testing system and a testing method thereof.

Background technique

Cohesion and internal friction angle are important shear strength indicators of soil, and are important parameters for calculation of earth pressure and foundation bearing capacity, analysis of embankment, slope, foundation pit, tunnel stability and design of their supporting structures. At present, cohesion and internal friction angle are mainly measured by drilling and taking soil samples for indoor tests. The indoor test methods used include direct shear test and triaxial compression test. The indoor test measurement method greatly disturbs the soil. After the soil sample is unloaded by stress release and reloaded by the indoor test, there must be differences between the shear strength index of the soil and the in-situ shear strength index on site, and the test results are highly discrete; and It is difficult to obtain the original sample of sandy soil by indoor test method, so it is impossible to measure the shear strength parameters of sandy soil.

Another method is to test soil shear strength parameters in situ. The method mainly includes field direct shear test and cross plate shear test. On-site direct shear tests need to be carried out in test holes, test pits, trenches or large-diameter boreholes. The advantage is that the soil sample is less disturbed and the test results are accurate and reliable. The disadvantage is that it is difficult to test deep soil and requires It consumes a lot of manpower and material resources. The advantage of the cross-plate shear test is that the equipment is simple and easy to operate. The disadvantage is that it is only suitable for measuring the undrained shear strength of saturated cohesive soil whose internal friction angle is basically equal to zero, and is not suitable for the cohesive soil with high hardness.

In addition, some geotechnical engineers proposed in-situ soil shear test, the main test equipment is as follows: ① BST in-situ soil shear tester produced by Handy Company of the United States; ② PHICOMETRE prototype produced by APAGEO Company in France In-situ drilling shear test system; ③ Chinese Invention Patent Publication No. CN104458445A discloses a kind of in-situ soil shear test device and test method; ④ Chinese Invention Patent Publication CN103728188A discloses soil in-situ shear and static Load tester. Among them, the BST in-situ soil in-hole shear tester produced by Handy Company of the United States has no normal and shear deformation test system, and cannot obtain the stress-strain relationship curves under normal stress at all levels, so it can only obtain The peak shear strength under normal stress and the corresponding cohesion and internal friction angle, and the equipment is driven by hand gear and manual reading, the shear rate and reading are greatly affected by human factors, which is time-consuming and laborious. In the PHICOMETRE in-situ drilling shear test system produced by French APAGEO company and the in-situ soil in-hole shear test device disclosed in the invention patent publication number CN104458445A, the shear head is a cylinder, and the length of the shear head is more than 20 cm , not suitable for thinner stratum tests with a thickness of less than 30cm, and manual hydraulic jacks are used, which is difficult to control a constant shear rate and affects the accuracy of test results; the in-situ shearing and The static load tester adopts the disk shearing soil formed by the pendulum supported by the support bar. This mechanical control cannot ensure that the pendulum is evenly opened, and there may be local shearing of the surrounding soil, and it is impossible to obtain reliable results. The test data, and when encountering medium and strong weathered residual soil, the broken rock blocks are likely to jam the support rod, resulting in the failure of the test.

In addition, when the above-mentioned types of in-situ shearing equipment are used for in-situ testing in deep formations, drilling rigs are required to cooperate with opening holes, and frequent loading and unloading of probe rods and lifting of drills are required, which greatly affects the integrity and stability of the borehole wall. Stability, which in turn affects the accuracy of the subsequent in-hole shear test results, and may easily cause the wall of the drilled hole to collapse. The in-situ shear probe buried in the hole cannot be taken out, which brings great difficulties to the deep in-situ shear test. Great risk and safety hazard.

Contents of the invention

In view of the deficiencies in the prior art above, an object of the present invention is to provide a method that is applicable to various terrains and soil properties, can significantly improve the quality and efficiency of shear tests in deep in-situ holes, measure multiple soil shear strength parameters and Deep in situ in-hole shear testing system with high safety.

Another object of the present invention is to provide a testing method using the above testing system.

For this reason, the technical scheme that the present invention adopts is as follows:

A deep in-situ shear test system, including a drilling rig, a tension-and-contraction casing core drilling tool, a casing, a mud pump, a drilling tool fishing device, a shear probe, a pull rod, a normal stress loading measurement device, Shear stress loading measurement device, dial indicator and data acquisition recorder, the drilling rig is used to drive the casing and the positioning end pipe connected to the bottom of the casing to drill into the formation; the positioning end pipe is used to drive the tensile The convergent casing coring tool is used for drilling and sampling; the mud pump is used to provide power for the reciprocating circulation of the mud during the drilling process, and to provide working pressure for the tension-converging casing coring tool; the drill A fishing device is used to lift it away from the casing after the tension-and-convergence casing coring tool is drilled and sampled; the pull rod is used to send the shear probe to a predetermined test depth; the normal The stress loading measurement device is used to apply a specified normal stress to the shear probe sent to the predetermined test depth; the shear stress loading measurement device is used to lift the shear probe at a constant rate until shear failure; the The dial gauge measures the shear deformation of the shear probe shear test soil through the pull rod; the shear probe, the normal stress load measurement device, the shear stress load measurement device, and the dial gauge They are respectively connected to the data acquisition recorder through data cables; the data acquisition recorder is used to record the shear deformation and shear force that change with time during the uniform lifting process of the shear probe.

Wherein, the shear probe includes a pair of shear plates, pore water pressure test probe, normal deformation test sensor, double-acting pressure cylinder and inverted U-shaped lifting frame, and the double-acting pressure cylinder is arranged horizontally; the pair of The shear plates are respectively fixed on the bottom of the cylinder body of the double-acting pressure cylinder and the output end of the piston rod, and each shear plate is a steel plate with serrated transverse grooves on the outside; the two lower ends of the inverted U-shaped lifting frame are respectively fixed on the upper end of the shear plate on the corresponding side; the center of each said shear plate is respectively equipped with a said pore water pressure test probe; said normal deformation test sensor is horizontally installed between two shear plates, Its two ends are respectively connected with the shear plate on the corresponding side.

The tension-converging casing core drilling tool includes a fishing spearhead, a casing, a spline tooth, a cutting plate, a tension-contracting shaft and a double-tube drilling tool, and the tension-converging shaft is arranged in the casing and can be Move up and down; the salvage spearhead 2-1 is arranged on the top of the stretching shaft 2-6, and a hole is opened inside the stretching shaft to form a water passage; the outside of the middle part of the outer casing is formed with spline teeth for connecting with the The spline sleeve of the positioning end pipe is meshed; the outer sleeve of the lower part of the spline teeth is provided with a cutting plate that can be pushed outward or converged inward depending on the downward or upward movement of the tension axis; the outer sleeve The lower part is threadedly connected to the double-tube drilling tool.

The mud pump is connected with the mud pool and the drilling rig respectively through rubber hoses.

The drilling tool fishing device includes an overshot, a lifting frame, a winch and a wire rope, and the overshot is suspended on the lifting frame through the wire rope traction on the winch; The salvage spearheads on the drilling rig are engaged.

The normal stress loading measurement device includes a normal stress control unit, a high-pressure gas cylinder, a pressure regulating valve and a high-pressure gas pipe, the high-pressure gas cylinder is screwed to one end of the pressure regulating valve, and the other end of the pressure regulating valve is connected to the normal direction. The stress control unit is connected through a high-pressure air pipe, and the normal stress control unit is also connected with the double-acting pressure cylinder in the shear probe through another high-pressure air pipe.

The shear stress loading measurement device includes a jack, an electric pump, a shear stress test unit, a caliper and a high-pressure oil pipe, and the jack is connected to the electric pump through a high-pressure oil pipe; the electric pump is used to drive the jack to provide a constant Increase speed.

The dial gauge is mounted on the caliper and fixed by a magnetic gauge frame.

When testing, the upper end of the shear probe is threadedly connected to the lower end of the tie rod, the shear probe is sent to the predetermined test depth through the tie rod, and the upper end of the pull rod passes through the reaction base plate laid at the hole opening and the shear stress loading measurement device in turn. The jack and the shear stress test unit are fixed by calipers, and the centers of the shear probe, pull rod, jack and the shear stress test unit are collinear.

A method for testing using the above-mentioned deep in-situ shear testing system, comprising the following steps:

S1: according to the conventional drilling method, stop after drilling the tension type casing core drilling tool 1.5 meters into the ground through the drilling rig;

S2: Thread the positioning end pipe to the bottom end of the first casing of the casing, install the casing on the drilling rig, connect the output hose of the mud pump to the mud valve of the drilling rig, and make the casing The spline sleeve of the positioning end pipe at the bottom end of the casing meshes with the spline teeth of the tension-converging casing core drilling tool;

S3: Turn on the mud pump, make the cutting plate of the tension-convergent casing core drilling tool open by water pressure, the drilling rig drives the casing and the positioning end pipe at the bottom of the casing to drill into the formation, and the positioning end The tube drives the tensioned casing core drilling tool to perform drilling and sampling;

S4: Turn off the mud pump every time 2m is drilled into the cohesive soil layer, every 1m into the silt and sandy soil layer, or drilled to the predetermined in-situ shear test depth, and use the drilling tool fishing device to pass The wire rope on the winch pulls the overshot suspended on the lifting frame to salvage the retractable casing core drilling tool, so that the overshot is connected with the fishing spearhead, and the overshot is lifted by the winch to make the retractable casing core drill The cutting plate of the tool becomes convergent, and the tension-convergent casing core drilling tool is lifted away from the casing;

S5: After taking out the sample in the core tube of the tension-and-convergence casing core drilling tool, repeat S3 and S4 until drilling to the predetermined shear test depth in the in-situ hole;

S6: Connect the shear probe to the pull rod, and connect the double-acting pressure cylinder of the shear probe to the normal stress control unit in the normal stress loading measurement device through the high-pressure air pipe, and the normal deformation test sensor and data acquisition record The instrument is connected through a data cable, and the high-pressure air pipe and data cable are tied on the pull rod smoothly;

Slowly send the shear probe to the test depth; make the upper end of the tie rod pass through the reaction floor laid at the hole opening and the jack and the shear stress test unit in the shear stress loading measurement device in turn, and then fix it with the caliper. The centers of probes, pull rods, jacks and shear stress test units should be collinear;

S7: Connect the high-pressure gas cylinder in the normal stress loading measurement device to one end of the pressure regulating valve, and the other end of the pressure regulating valve is connected to the normal stress control unit through a high-pressure gas pipe;

Connect the jack in the shear stress loading measurement device with the electric pump through a high-pressure oil pipe;

The dial indicator is erected on the caliper and fixed by a magnetic gauge holder;

The normal stress control unit in the normal stress load measurement device, the shear stress test unit in the shear stress load measurement device, the electric pump, and the dial indicator 11 are connected to the data acquisition recorder through a data cable;

S8: Apply an initial small normal stress through the normal stress control unit described in the method, so that the shear plate of the shear probe is in contact with the borehole wall, and then release the normal stress, and record the data The instrument's initial normal stress, shear force, normal deformation, shear deformation, pore water pressure and time readings are initialized to 0;

S9: Apply the first-level normal stress through the normal stress control unit in the normal stress loading measurement device, and after the soil is consolidated for a certain period of time, observe the soil consolidation through the pore water pressure curve. For non-cohesive soil, usually It needs to be consolidated for 5 minutes, and the cohesive soil is consolidated for 10 to 20 minutes;

S10: Turn on the electric pump in the shear stress loading measurement device, drive the jack to lift the shear probe at a constant lifting rate of 0.8mm/min until shear failure;

S11: Turn off the electric pump in the shear stress loading measurement device, and remove the normal stress in the double-acting pressure cylinder of the shear probe through the normal stress control unit in the normal stress loading measurement device, so that the shear Close the probe, reset the jack, repeat S9~S10 to carry out the next level of normal stress test, and carry out 4~5 levels of different normal stress in-situ shear tests in the hole at each test point;

S12: Move the shear probe out of the borehole, repeat S3-S11, and carry out the in-situ in-hole shear test at the next point.

The present invention has the following beneficial effects:

1. The system is simple in structure and easy to operate, which can significantly improve the quality and efficiency of shear testing in deep in-situ holes;

2. The integrity and stability of the test hole wall are good, and the test data is accurate and reliable;

3. It avoids the risk of buried drilling for deep in-situ shear test, especially suitable for deep in-situ shear test;

4. It can quickly measure the relationship curve of shear stress and shear displacement under normal stress conditions at all levels, and then obtain the soil shear strength parameters corresponding to proportional strength, yield strength, peak strength and residual strength, which enriches the test As a result, it is convenient to select the corresponding shear strength parameters according to different working conditions in the process of engineering application;

5. It has a wide range of applications and is suitable for various terrains and soil qualities.

Description of drawings

Fig. 1 is the state schematic diagram when utilizing the testing system of the present invention to carry out tension-and-convergence casing coring drilling operation;

Fig. 2 is the state schematic diagram when utilizing the test system of the present invention to carry out the shear test in the deep in situ hole;

Fig. 3 is the structural representation of shearing probe in this system;

Fig. 4 is the schematic diagram of the section structure of the expansion and convergence type reaming drill bit in this system;

In the picture:

1. Drilling rig 1-1, drilling tower 1-2, power head

2. Converging casing core drilling tool 2-1, salvage spearhead 2-2, water passage

2-3, jacket 2-4, spline teeth 2-5, cutting plate

2-6. Tension shaft 2-7. Double-tube drilling tool 3. Casing

3-1. Positioning end pipe 4. Mud pump 4-1. Mud pool

4-2. Rubber hose 5. Drilling tool fishing device 5-1. Fisher

5-2, hoisting frame 5-3, winch 5-4, wire rope

6. Shear probe 6-1, shear plate 6-2, pore water pressure test probe

6-3. Normal deformation test sensor 6-4. Double-acting pressure cylinder 6-5. Lifting frame

7. Tie rod 8. Reaction base plate 9. Normal stress loading measuring device

9-1. Normal stress control unit 9-2. High pressure cylinder 9-3. Pressure regulating valve

9-4. High-pressure gas pipe 10. Shear stress loading measuring device 10-1. Jack

10-2. Electric pump 10-3. Shear stress test unit 10-4. Calipers

10-5. High pressure oil pipe 11. Dial gauge 12. Magnetic gauge frame

13. Data acquisition recorder 14. Data cable

Detailed ways

The deep in-situ in-hole shear test system and its test method of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in Figures 1 and 2, the deep in-situ in-hole shear test system of the present invention includes: a drilling rig 1, a tension-converging casing core drilling tool, a casing 3, a mud pump 4, a drilling tool fishing device 5, Shear probe 6, pull rod 7, reaction base plate 8, normal stress loading measurement device 9, shear stress loading measurement device 10, dial indicator 11, magnetic meter frame 12, data acquisition recorder 13 and data cable 14.

The drilling rig 1 includes a drilling tower 1-1 and a power head 1-2, which are used to drive the casing 3 and the positioning end pipe 3-1 at the bottom of the casing 3 to drill into the formation. The positioning end pipe 3-1 is used to drive the tensioned casing core drilling tool 2 for drilling and sampling. After drilling into the predetermined formation, the mud pump is turned off; 2 Lift off casing 3. Then the shear probe 6 is sent to the predetermined test depth through the pull rod 7, and the specified normal stress is applied to the shear probe through the normal stress loading measurement device. After standing for a certain period of time, the shear stress measurement device is loaded at a constant rate Lift the shear probe, and use the data acquisition recorder to record the shear deformation and shear force that change with time during the uniform lifting process of the shear probe.

Specifically, the tension-converging casing core drilling tool can adopt the casing core drilling tool disclosed in the Chinese Invention Patent Application Publication No. CN103603625A, or the tension-contraction casing core drilling tool 2 shown in Fig. 4 .

Referring to Fig. 4, the stretch-contract casing core drilling tool 2 includes a salvage spearhead 2-1, a jacket 2-3, a spline tooth 2-4, a cutting plate 2-5, a stretch-contract shaft 2-6 and a double-tube drill 2-7. The stretching shaft 2-6 is located in the outer jacket 2-3, and can move up and down in the outer jacket 2-3; the top of the stretching shaft 2-6 is provided with a salvage spearhead 2-1, and the inner opening forms a water passage 2- 2; the outer spline teeth 2-4 in the middle of the overcoat 2-3 are used to engage with the spline sleeve of the positioning end pipe 3-1; the inside of the overcoat 2-3 at the bottom of the spline teeth 2-4 is equipped with The cutting plate 2-5 pushed outwards or converged inward by the downward or upward movement of the stretching axis 2-6; the lower part of the jacket 2-3 is threadedly connected to the double-pipe drilling tool 2-7.

The part of the tensioning axis 2-6 close to the lower end of the cutting plate 2-5 is thicker at the top and thinner at the bottom, and the opening and convergence of the cutting plate 2-5 can be controlled by moving the tensioning axis 2-6 up and down. When the mud pump is turned on, under the action of water pressure, the tensioning shaft 2-6 slides down, and the original contracted cutting plate 2-5 is pushed out, forming the cutting plate in an open state as shown in Figure 4 . When upwardly promoting the salvage spearhead, the tensioning shaft 2-6 slides upwards, and the cutting plate 2-5 retracts.

The cutting plate is in an open state when the mud pump is turned on, and at this time the bottom end of the positioning end pipe is combined with the shoulder of the cutting plate; when the mud pump is turned off and the fishing spearhead is pulled, the cutting plate becomes convergent state.

The mud pump 4 is connected to the mud pool 4-1 through a rubber hose 4-2, and the mud pump 4 is connected to the drilling rig 1 through a rubber hose 4-2. The mud pump is the power source for the reciprocating circulation of the mud required in the drilling process. The mud plays the role of removing rock powder, cooling the drill bit, and lubricating the drilling tool during the drilling process. The opening of the cutting plates 2-5 provides pressure.

The drilling tool fishing device 5 includes a fishing device 5-1, a lifting frame 5-2, a winch 5-3 and a wire rope 5-4. The overshot 5-1 is pulled and suspended on the hoisting frame 5-2 by the wire rope 5-4 on the winch 5-3; Spearheads engaged 2-1.

As shown in Figure 3, the shear probe 6 includes a pair of shear plates 6-1, a pore water pressure test probe 6-2, a normal deformation test sensor 6-3, a double-acting pressure cylinder 6-4 and an inverted U-shaped lifting frame 6-5. Wherein, the double-acting pressure cylinder 6-4 is arranged horizontally; a pair of shearing plates 6-1 are fixedly mounted on the cylinder bottom of the double-acting pressure cylinder 6-4 and the output end of the piston rod respectively, and each shearing plate 6-1 are all steel plates with serrated transverse grooves on the outside, that is, a plurality of transverse grooves are formed on the outer side of the shear plate from top to bottom, and in the longitudinal section of the shear plate, the side where the transverse grooves are located is serrated; The two lower ends of the inverted U-shaped lifting frame 6-5 are respectively fixed on the upper ends of the corresponding shear plates 6-1; each center of each shear plate 6-1 is equipped with a pore water pressure test probe 6-2: The normal deformation test sensor 6-3 is installed horizontally between two shear plates 6-1, and its two ends are respectively connected to the shear plates 6-1 on the corresponding sides.

The normal stress loading measurement device 9 includes a normal stress control unit 9-1, a high-pressure gas cylinder 9-2, a pressure regulating valve 9-3 and a high-pressure gas pipe 9-4. The high-pressure gas cylinder 9-2 is threadedly connected to one end of the pressure regulating valve 9-3, and the other end of the pressure regulating valve 9-3 is connected to the normal stress control unit 9-1 through the high-pressure gas pipe 9-4, and the normal stress The control unit 9-1 is simultaneously connected with the double-acting pressure cylinder 6-4 in the shear probe 6 through another high-pressure air pipe 9-4.

The shear stress loading measuring device 10 includes a jack 10-1, an electric pump 10-2, a shear stress testing unit 10-3, a caliper 10-4 and a high pressure oil pipe 10-5. The jack 10-1 is connected to the electric pump 10-2 through a high-pressure oil pipe 10-5; the electric pump 10-2 drives the jack 10-1 to provide a constant lifting rate; the shear stress test unit 10-3 is placed on the jack 10-1 above. During the test, the caliper 10-4 tightens the pull rod 7 so that the reaction base plate 8, the jack 10-1, and the shear stress testing unit 10-3 are closely connected to the axis.

The dial gauge 11 is erected on the caliper 10 - 4 and fixed by a magnetic gauge frame 12 . The shear probe 6 , the normal stress loading measuring device 9 , the shear stress loading measuring device 10 , and the dial indicator 11 are respectively connected to the data acquisition recorder 13 through the data cable 14 .

When testing, the shear probe 6 is threadedly connected to the pull rod 7 through the lifting frame 6-5. The upper end of the pull rod 7 passes successively through the reaction base plate 8 laid at the hole opening and the jack 10-1 and the shear stress test unit 10-3 in the shear stress loading measurement device 10, and then fixed by the caliper 10-4; The centers of the shear probe 6, the pull rod 7, the jack 10-1 and the shear stress test unit 10-3 are collinear.

The test process of deep in-situ in-hole shear test with the above test system is as follows:

S1: According to the conventional drilling method, the tensioned casing core drilling tool 2 is drilled 1.5 meters underground through the drilling rig 1 and then stopped;

S2: Thread the positioning end pipe 3-1 to the bottom end of the first section of the casing 3, install the casing 3 on the drilling rig 1, connect the output hose 4-2 of the mud pump 4 to the mud valve of the drilling rig, and Make the spline sleeve of the positioning end pipe 3-1 at the bottom of the casing 3 mesh with the spline teeth 2-4 of the tension-converging casing core drilling tool 2;

S3: Turn on the mud pump 4, make the cutting plate 2-4 of the tension-convergent casing core drilling tool 2 open by water pressure, and the drilling rig 1 drives the casing 3 and the positioning end pipe 3- at the bottom of the casing 3 1. Drilling into the formation, positioning the end pipe 3-1 to drive the tensioned casing core drilling tool 2 to perform drilling and sampling;

S4: Turn off the mud pump 4 every time 2m is drilled into the cohesive soil layer, 1m into the silt and sandy soil layer, or reach the predetermined shear test depth in the in-situ hole, and use the drilling tool fishing device 5 to pass The wire rope 5-4 on the winch 5-3 pulls the overshot 5-1 suspended on the hoisting frame 5-2 to salvage the retractable casing core drilling tool 2, so that the overshot 5-1 is in phase with the fishing spearhead 2-1 Engagement, the overshot 5-1 is lifted by the winch 5-3 so that the cutting plate 2-4 of the tension-convergent casing core drilling tool 2 becomes convergent, and the tension-convergence casing core drilling tool 2 is lifted away from the casing tube 3;

S5: After taking out the sample in the core pipe 2-7 of the tension-converging casing core drilling tool 2, repeat S3 and S4 until drilling to the predetermined shear test depth in the in-situ hole;

S6: Connect the shear probe 6 to the pull rod 7, and pass the double-acting pressure cylinder 6-4 of the shear probe 6 and the normal stress control unit 9-1 in the normal stress loading measurement device 9 through the high-pressure air pipe 9 -4 connected, the normal deformation test sensor 6-3 is connected with the data acquisition recorder 13 through the data cable 14, and the high-pressure air pipe 9-4 and the data cable 14 are tied on the pull rod 7 smoothly;

Slowly release the shear probe 6 to the test depth; make the upper end of the pull rod 7 sequentially pass through the reaction floor 8 laid at the hole opening and the jack 10-1 and the shear stress test unit 10 in the shear stress loading measurement device 10 After -3, it is fixed by the caliper 10-4, and the centers of the shear probe 6, the pull rod 7, the jack 10-1 and the shear stress test unit 10-3 should be collinear;

S7: Connect the high-pressure gas cylinder 9-2 in the normal stress loading measurement device 9 to one end of the pressure regulating valve 9-3, and the other end of the pressure regulating valve 9-3 passes through the normal stress control unit 9-1 High-pressure air pipe 9-4 is connected;

Connect the jack 10-1 in the shear stress loading measurement device 10 with the electric pump 10-2 through the high-pressure oil pipe 10-5;

The normal stress control unit 9-1 in the normal stress load measurement device 9, the shear stress test unit 10-3 in the shear stress load measurement device 10, the electric pump 10-2, and the dial indicator 11 pass through the data cable 14 Link to each other with data acquisition recorder 13;

S8: Apply an initial small normal stress through the normal stress control unit 9-1, make the shear plate of the shear probe 6 contact the borehole wall, and then release the normal stress, and The initial normal stress, shear force, normal deformation, shear deformation, pore water pressure and time readings of the data acquisition recorder 13 are initialized to 0;

S9: Apply the first-level normal stress through the normal stress control unit 9-1 in the normal stress loading measurement device 9, and after the soil is consolidated for a certain period of time, observe the soil consolidation through the pore water pressure curve. Non-cohesive soil usually needs to be consolidated for 5 minutes, and cohesive soil is consolidated for 10-20 minutes;

S10: Turn on the electric pump 10-2 in the shear stress loading measuring device 10, and drive the jack 10-1 to lift the shear probe 6 at a constant lifting rate of 0.8 mm/min until shear failure;

S11: Turn off the electric pump 10-2 in the shear stress loading measurement device 10, and set the double-acting pressure cylinder 6-1 of the shear probe 6 through the normal stress control unit 9-1 in the normal stress loading measurement device 9 Remove the normal stress in 4, close the shear probe, reset the jack 10-1, repeat S9-S10 to carry out the next level of normal stress test, and carry out 4-5 levels of different normal stress at each test point In situ in-hole shear testing;

S12: Move the shear probe 6 out of the borehole, repeat S3-S11, and carry out the in-situ in-hole shear test at the next point.

After the test, disassemble and clean the equipment, and pack it after maintenance.

To sum up, the present invention provides a deep in-situ hole shear test system and test method based on tension-and-convergence casing core drilling technology, which can significantly improve the quality and efficiency of deep in-situ hole shear tests and avoid deep in-situ borehole shear testing. The in-situ shear test buried drilling risk can quickly test the soil shear strength parameters corresponding to the proportional strength, yield strength, peak strength and residual strength of the soil in deep formations, and is suitable for various terrains and soil qualities.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any way. All simple modifications, changes and equivalent structural changes made to the above embodiments according to the essence of the present invention still belong to the protection of the present invention. scope.

Claims (10)

1. shearing test system in a kind of hole of deep layer original position, it is characterised in that：Including drilling machine (1), divergent-convergent type casing core bit (2), casing (3), slush pump (4), drilling tool fishing device (5), shear Probe (6), pull rod (7), normal stress load measure dress (9), shear stress load measuring equipment (10), amesdial (11) and data acquisition recorder (13) are set,

The drilling machine (1) is used to drive described sleeve pipe (3) and be connected to positioning end pipe (3-1) the drilling stratum of casing (3) bottom；

The positioning end pipe (3-1) is for driving the divergent-convergent type casing core bit (2) to carry out drill sampling；

The slush pump (4) is used in drilling process provide power for the flowing of mud reciprocation cycle, and is the divergent-convergent type set Pipe core bit (2) provides operating pressure；

The drilling tool fishing device (5) is used for will be described in its lift-off after divergent-convergent type casing core bit (2) drill sampling Casing (3)；

The pull rod (7) is for sending the shear Probe (6) to predetermined experiment depth；

The normal stress load measuring equipment (9) is used to apply to the shear Probe (6) for being sent to predetermined experiment depth specified Normal stress；

The shear stress load measuring equipment (10) is used to promote the shear Probe (6) with constant rate of speed, until failure by shear；

The amesdial (11) measures the shear deformation of shear Probe (6) the shearing test soil body by the pull rod (7)；

The shear Probe (6), normal stress load measuring equipment (9), shear stress load measuring equipment (10), amesdial (11) It is connected respectively with the data acquisition recorder (13) by data cable；

The data acquisition recorder (13) is used to record cutting of changing over time in the shear Probe (6) at the uniform velocity lifting process Shear deformation and shearing force.

2. shearing test system in the hole of deep layer original position according to claim 1, it is characterised in that：The shear Probe (6) Including a pair of of shear plate (6-1), pore water pressure test probe (6-2), normal deformation test sensor (6-3), double acting pressure Power cylinder (6-4) and inverted U hoisting frame (6-5),

The double acting pressurised cylinder (6-4) is horizontally disposed；

The pair of shear plate (6-1) is packed in the output of the cylinder base and piston rod of double acting pressurised cylinder (6-4) respectively End, every piece of shear plate (6-1) is the steel plate of outer side band zigzag translot；

Two lower ends of the inverted U hoisting frame (6-5) are separately fixed at the upper end of the shear plate (6-1) of respective side；Each institute State the center of shear plate (6-1) respectively dress there are one the pore water pressure test probe (6-2)；The normal deformation test sensing Device (6-3) is horizontally arranged between two pieces of shear plates (6-1), and its both ends is connect with the shear plate of corresponding side (6-1) respectively.

3. shearing test system in the hole of deep layer original position according to claim 1, it is characterised in that：The divergent-convergent type casing takes Core drilling tool (2) include spear-head (2-1), housing (2-3), spline tooth (2-4), cutting plate (2-5), hold back axis (2-6) and pair Pipe drilling tool (2-7),

It holds back axis (2-6) for described to be located in the housing (2-3), and can be moved up and down in housing (2-3)；

The top for holding back axis (2-6) is being opened in spear-head (2-1) setting, and water was formed opening the internal openings for holding back axis (2-6) Channel (2-2)；

It is formed with spline tooth (2-4) on the outside of the middle part of the housing (2-3), for the spline housing with the positioning end pipe (3-1) It is meshed；

Be equipped in the housing (2-3) of spline tooth (2-4) lower part can by it is described open hold back moving down or moving up for axis (2-6) and to Extrapolated or toe-in cutting plate (2-5)；

Housing (2-3) lower thread connects the two-tube drilling tool (2-7).

4. shearing test system in the hole of deep layer original position according to claim 1, it is characterised in that：The slush pump (4) with One mud pit (4-1) is connected by sebific duct respectively with the drilling machine (1).

5. shearing test system in the hole of deep layer original position according to claim 1, it is characterised in that：The drilling tool fishing device (5) include fisher (5-1), upending frame (5-2), winch (5-3) and steel wire rope (5-4),

The fisher (5-1) is suspended on by steel wire rope (5-4) traction on winch (5-3) on the upending frame (5-2)；

When work, the fisher (5-1) engages with the spear-head (2-1) on divergent-convergent type casing core bit (2).

6. shearing test system in the hole of deep layer original position according to claim 1, it is characterised in that：The normal stress load Measuring equipment (9) includes normal stress control unit (9-1), gas cylinder (9-2), pressure regulator valve (9-3) and high-pressure air pipe (9- 4), the gas cylinder (9-2) connect with the threaded one end of pressure regulator valve (9-3), the other end and normal stress of pressure regulator valve (9-3) Control unit (9-1) by high-pressure air pipe (9-4) be connected, normal stress control unit (9-1) at the same in shear Probe (6) Double acting pressurised cylinder (6-4) is connected by another high-pressure air pipe (9-4).

7. shearing test system in the hole of deep layer original position according to claim 1, it is characterised in that：The shear stress loading capacity It includes jack (10-1), electrodynamic pump (10-2), shear stress test cell (10-3), clamp (10-4) and high pressure to survey device (10) Oil pipe (10-5), the jack (10-1) are connected with the electrodynamic pump (10-2) by high-pressure oil pipe (10-5)；It is described electronic Pump (10-2) provides constant promotion rate for driving the jack (10-1).

8. shearing test system in the hole of deep layer original position according to claim 1, the amesdial (11) is erected at clamp On (10-4), and it is fixed by magnet stand (12).

9. shearing test system in the deep layer original position hole according to any one of claim 1-8, it is characterised in that：It is surveyed When examination, shear Probe (6) upper end is connect with pull rod (7) lower thread, and shear Probe (6) is sent deep to predetermined experiment by pull rod Degree, pull rod (7) upper end sequentially pass through in the counter-force bottom plate (8) being laid at drilling orifice and shear stress load measuring equipment (10) Jack (10-1) and shear stress test cell (10-3) after it is fixed by clamp (10-4), shear Probe (6), pull rod (7), The center of jack (10-1) and shear stress test cell (10-3) is conllinear.

10. a kind of method that shearing test system is tested in deep layer original position hole using described in claim 9, including it is following Step：

S1:The divergent-convergent type casing core bit (2) is crept by underground 1.5 by the drilling machine (1) according to conventional drilling method Stop after rice；

S2：The positioning end pipe (3-1) is threadedly coupled to the first section casing shoe of described sleeve pipe (3), and by described sleeve pipe (3) It is installed on drilling machine (1), the output sebific duct (4-2) of the slush pump (4) is connected to the mud valve of drilling machine, and makes described sleeve pipe (3) The spline housing of the positioning end pipe (3-1) of bottom end is meshed with the spline tooth (2-4) of the divergent-convergent type casing core bit (2)；

S3：The slush pump (4) is opened, makes the cutting plate (2-5) of the divergent-convergent type casing core bit (2) be by hydraulic pressure Open state, drilling machine (1) drive sleeve (3) and the positioning end pipe (3-1) positioned at casing (3) bottom creep into stratum, positioning end pipe (3- 1) divergent-convergent type casing core bit (2) is driven to carry out drill sampling；

S4：It often creeps into 2m, silt and sandy soil stratum and often creeps into shearing test in 1m or drilling to predetermined hole in situ in cohesive soil stratum After depth, closes slush pump (4) and pass through the steel wire rope (5-4) on the winch (5-3) using the drilling tool fishing device (5) Traction is suspended on fisher (5-1) on upending frame (5-2) and salvages divergent-convergent type casing core bit (2), make fisher (5-1) with Spear-head (2-1) engages, and promotes fisher (5-1) by winch (5-3) by makes cutting for divergent-convergent type casing core bit (2) Cutting plate (2-5) becomes convergence state, by divergent-convergent type casing core bit (2) lift-off casing (3)；

S5：After sample in the core barrel (2-7) of divergent-convergent type casing core bit (2) is taken out, S3, S4 are repeated until creeping into extremely Shearing test depth in predetermined original position hole；

S6：Shear Probe (6) and pull rod (7) are connected, and by the double acting pressurised cylinder (6-4) and method of shear Probe (6) Normal stress control unit (9-1) into stress loading measuring equipment (9) is connected by high-pressure air pipe (9-4), normal deformation Test sensor (6-3) is connected with data acquisition recorder (13) by data cable (14), by high-pressure air pipe (9-4) and data Cable (14) is smoothed out with the fingers along binding on pull rod (7)；

Shear Probe (6) is slowly broadcasted to experiment depth；Make pull rod (7) upper end sequentially pass through be laid on it is anti-at drilling orifice After power bottom plate (8) and shear stress load jack (10-1) and shear stress test cell (10-3) in measuring equipment (10), lead to It is fixed to cross clamp (10-4), shear Probe (6), pull rod (7), jack (10-1) and shear stress test cell (10-3) center It should be conllinear；

S7：Gas cylinder (9-2) in normal stress load measuring equipment (9) is connect with the threaded one end of pressure regulator valve (9-3), The other end of pressure regulator valve (9-3) is connected with normal stress control unit (9-1) by high-pressure air pipe (9-4)；

Jack (10-1) in shear stress load measuring equipment (10) is passed through into high-pressure oil pipe (10-5) with electrodynamic pump (10-2) It is connected；

Amesdial (11) is erected on clamp (10-4), fixed by magnet stand (12)；

In normal stress control unit (9-1), shear stress load measuring equipment (10) in normal stress load measuring equipment (9) Shear stress test cell (10-3) and electrodynamic pump (10-2), amesdial (11) pass through data cable (14) and data acquiring and recording Instrument (13) is connected；

S8：The normal stress for applying an initial very little by the normal stress control unit (9-1), makes shear Probe (6) Shear plate is contacted with borehole wall, later lays down this normal stress, and the initial normal direction of data acquisition recorder (13) is answered Power, shearing force, normal deformation, shear-deformable, pore water pressure and time read are initialized as 0；

S9：Normal stress control unit (9-1) the application first order normal direction in measuring equipment (9) is loaded by normal stress to answer Power makes soil consolidation after a certain period of time, observes soil solidifying situation by pore water pressure curve, non-cohesive soil is usually needed Consolidation 5 minutes, cohesive soil consolidate 10~20 minutes；

S10：The electrodynamic pump (10-2) in shear stress load measuring equipment (10) is opened, driving jack (10-1) is with 0.8mm/ The constant promotion rate of min promotes shear Probe (6), until failure by shear；

S11：The electrodynamic pump (10-2) in shear stress load measuring equipment (10) is closed, and measuring equipment is loaded by normal stress (9) the normal stress control unit (9-1) in unloads the normal stress in the double acting pressurised cylinder (6-4) of shear Probe (6) It removes, shear Probe is made to be closed, and jack (10-1) is made to reset, repeat S9~S10 and carry out the test of next stage normal stress, each It tests point and carries out shearing test in the hole of 4~5 grades of different normal stress original positions；

S12：Shear Probe (6) is removed and is drilled, S3~S11 is repeated, carries out shearing test in the hole in situ of next point.