Apparatus for measuring in-situ stress in a fault fracture zone and method of use

Abstract

The application discloses a device for measuring ground stress of a fault fracture zone, which comprises a PVC pipe, a hollow connecting rod, an automatic telescopic pressure test assembly, a hydraulic lead and a pressurizing assembly. The PVC pipe is placed in a test hole for putting the hollow connecting rod and the automatic telescopic pressure test assembly into the test hole. The hollow connecting rod is connected with the automatic telescopic pressure test assembly. The automatic telescopic pressure test assembly is connected with the hydraulic lead and the pressurizing assembly. The application further discloses a use method of the device for measuring ground stress of a fault fracture zone. Compared with the prior art, the device for measuring ground stress of a fault fracture zone can effectively measure the ground stress of the fault fracture zone, and has the advantages of simple operation and convenient recovery.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of in-situ measurement of ground stress in geotechnical engineering, and particularly relates to a device for measuring ground stress in a fault fracture zone and a use method thereof. BACKGROUND

[0002] The mechanical strength of the fault fracture zone is low, which makes it very difficult to effectively test the ground stress in the fault fracture zone, and there are great limitations and measurement errors.

[0003] The mainstream traditional method for measuring ground stress includes stress relief method and hydraulic fracturing method. However, both of these methods are mainly suitable for the environment of intact rock mass, and they are difficult to test the ground stress in the broken rock mass environment such as the fault fracture zone. In addition, there is a deep soft rock ground stress testing technology based on the principle of rheological stress recovery, although it can effectively evaluate the ground stress in the deep loose surrounding rock of coal mine, but this technology has its limitations, that is, it can only accurately test for specific measuring points. Moreover, the pressure cell used in the deep soft rock ground stress testing technology is wrapped by concrete mortar and does not directly contact with the rock mass, and this indirect contact method often leads to a significant increase in the error of the ground stress test results due to the difference in elastic modulus between the mortar and the rock mass.

[0004] Therefore, how to provide a device for measuring ground stress in a fault fracture zone so that it can effectively test the ground stress in the fault fracture zone is a technical problem that the person skilled in the art needs to solve. SUMMARY

[0005] In view of the problems in the prior art, the technical problem to be solved by the present application is to provide a testing device that can effectively test the ground stress in the fault fracture zone.

[0006] To achieve the above object, the application provides a device for measuring ground stress in a fault fracture zone, which comprises a PVC pipe, a hollow connecting rod in a cylindrical structure, a plurality of hollow rod through holes being arranged on the sidewall of the hollow connecting rod with the central axis of the hollow connecting rod as the axis and the hollow connecting rod being located in the interior of the PVC pipe, an automatic telescopic pressure testing assembly comprising a plurality of telescopic hydraulic rods corresponding to the number of the hollow rod through holes, a plurality of arc-shaped steel blocks corresponding to the number of the telescopic hydraulic rods, and a plurality of arc-shaped pressure testing pieces corresponding to the number of the arc-shaped steel blocks, each of the hollow rod through holes and each of the telescopic hydraulic rods being in one-to-one correspondence, the top of each of the telescopic hydraulic rods penetrating through the corresponding hollow rod through hole and being located in the hollow connecting rod, each of the telescopic hydraulic rods being fixedly connected with the corresponding arc-shaped steel block, each of the arc-shaped steel blocks being fixedly connected with the corresponding arc-shaped pressure testing piece, the plurality of telescopic hydraulic rods, the plurality of arc-shaped steel blocks and the plurality of arc-shaped pressure testing pieces being located in the PVC pipe, a plurality of hydraulic wires corresponding to the number of the telescopic hydraulic rods, one end of each of the hydraulic wires being connected with the corresponding telescopic hydraulic rod, and a pressurizing assembly, one end of the pressurizing assembly being connected with the other end of the plurality of hydraulic wires.

[0007] In the first aspect, a hydraulic threaded hole is arranged in the inner side center of each of the arc-shaped steel blocks, the tail of each of the telescopic hydraulic rods is in a threaded form and is matched with the corresponding hydraulic threaded hole, a testing piece threaded hole is arranged in the outer side center of each of the arc-shaped steel blocks, and a threaded rod is arranged in the central position of each of the arc-shaped pressure testing pieces and is matched with each of the testing piece threaded holes.

[0008] In the first aspect, the hollow connecting rod comprises: a first hollow rod comprising two first semicircular steel pipes spliced into a cylindrical structure by a first circular hoop, an inner side of one end of the first hollow rod being threaded; a second hollow rod comprising two second semicircular steel pipes spliced into a cylindrical structure by a second circular hoop, an outer side of one end of the second hollow rod being threaded; wherein the inner diameter length of the first hollow rod is the same as the outer diameter length of the second hollow rod, and the first hollow rod is threadedly connected with the second hollow rod; the other end of the second hollow rod is provided with a plurality of hollow rod through holes which are uniformly distributed on the side wall of the second hollow rod with the central axis of the second hollow rod as the axis, and the top of the telescopic hydraulic rod is located in the second hollow rod; a threading hole is formed on one side wall of each telescopic hydraulic rod on the second hollow rod, and the other end of each hydraulic lead wire is sequentially connected with the pressurizing assembly through the corresponding threading hole, the second hollow rod, the first hollow rod and the data acquisition system.

[0009] In the first aspect, the device for measuring the ground stress of a fault fracture zone further comprises a data acquisition system, wherein the top of each telescopic hydraulic rod is provided with a displacement sensor, and each displacement sensor is connected with the data acquisition system.

[0010] In the first aspect, the automatic telescopic pressure testing assembly further comprises: a plurality of groups of arc-shaped pressure testing piece leads, one end of each group of arc-shaped pressure testing piece leads being connected with a corresponding arc-shaped pressure testing piece; each group of arc-shaped pressure testing piece leads comprises two arc-shaped pressure testing piece leads, one end of one arc-shaped pressure testing piece lead being connected with one end of a corresponding arc-shaped pressure testing piece, and one end of the other arc-shaped pressure testing piece lead being connected with the other end of the corresponding arc-shaped pressure testing piece; a plurality of groups of testing piece lead holes adapted to the number of groups of arc-shaped pressure testing piece leads, one group of testing piece lead holes being formed on each arc-shaped steel block, and each group of testing piece lead holes comprising two testing piece lead holes; the connection points of each arc-shaped pressure testing piece lead and the corresponding arc-shaped pressure testing piece are one-to-one correspondingly distributed in each testing piece lead hole, and each testing piece lead hole is adapted to each arc-shaped pressure testing piece lead; wherein one end of each arc-shaped pressure testing piece lead is connected with the corresponding arc-shaped pressure testing piece, and the other end of each arc-shaped pressure testing piece lead is sequentially connected with the data acquisition system through the corresponding testing piece lead hole, the corresponding threading hole, the second hollow rod and the first hollow rod.

[0011] In the first aspect, the automatic telescopic pressure testing assembly further comprises a rubber ring in a cylindrical hollow structure, a plurality of threaded holes are formed in the cylinder of the rubber ring and correspond to the number of the threaded rods, each threaded rod is distributed one-to-one with each threaded hole, the rubber ring is sleeved on the plurality of arc-shaped steel blocks to cover the plurality of arc-shaped steel blocks and the plurality of telescopic hydraulic rods, the rubber ring is located between each arc-shaped steel block and each arc-shaped pressure testing piece, each threaded rod passes through the corresponding threaded hole and is connected with the corresponding arc-shaped steel block (32), and two hollow rod holes are symmetrically formed at two ends of the rubber ring.

[0012] In the first aspect, the number of the telescopic hydraulic rods is 4.

[0013] In the first aspect, the central axis of the arc-shaped pressure testing piece is on the same straight line as the central axes of the first hollow rod and / or the second hollow rod.

[0014] The application further provides a use method of the device for measuring the ground stress of a fault fracture zone, which is used for the device for measuring the ground stress of a fault fracture zone and comprises the following steps: determining the drilling position of the fault fracture zone through local collection of geological data and on-site investigation, drilling a test hole with a diameter of d and a depth of h at the determined drilling position by using a drilling device, and when there is no design requirement, the final hole position deviation is not greater than 10 cm, and the hole deviation error is not greater than 2%. A lubricant is applied to the surface of a PVC pipe and the PVC pipe is placed in the test hole. A hollow connecting rod is assembled, and the hollow connecting rod is assembled with an automatic telescopic pressure testing assembly. A hydraulic wire is connected with a pressurizing assembly through the hollow connecting rod, and a displacement sensor wire and an arc-shaped pressure testing piece wire are connected with a data acquisition system through the hollow connecting rod. Then, the assembled hollow connecting rod and the automatic telescopic pressure testing assembly are placed in the PVC pipe to a designed test depth. At a test depth of h1, the PVC pipe is pulled out of the automatic telescopic pressure testing assembly, the data acquisition system is opened to start real-time monitoring of pressure data, the pressurizing assembly is started to make the telescopic hydraulic rod elongate to pressurize the arc-shaped steel block and the arc-shaped pressure testing piece, the arc-shaped pressure testing piece is tightly attached to the test hole wall, and when the test pressure value is stable, the pressure data acquisition and pressurization are stopped. The collected pressure data is σ 11 Then, the automatic telescopic pressure testing assembly is rotated at an angle of θ, and the pressure is continuously increased until the pressure value is stable and the pressure data σ 12Then stop collecting pressure data and pressurizing, and then continue rotating by θ angle and continue pressurizing until the pressure value is stable and collect pressure data σ 13 , continue rotating and pressurizing by θ angle until the position of testing σ 11 is reached, and the test of the stress of the fault fracture zone at the depth of h1 is completed; then the telescopic hydraulic rod is retracted, the assembled hollow connecting rod and the automatic telescopic pressure testing assembly are lifted to a new testing depth h2, and at the same time the PVC pipe is continuously pulled out until the automatic telescopic pressure testing assembly is completely exposed from the PVC pipe, and then the telescopic hydraulic rod is elongated by the pressurizing assembly to pressurize the arc-shaped steel block and the arc-shaped pressure testing sheet, so that the arc-shaped pressure testing sheet is tightly attached to the test hole wall, and when the tested pressure value is stable, stop collecting pressure data and pressurizing, and the collected pressure data is σ 21 , then the automatic telescopic pressure testing assembly is rotated by θ angle, and continues to be pressurized until the pressure value is stable and pressure data σ 22 is collected, then stop collecting pressure data and pressurizing, and then continue rotating by θ angle and continue pressurizing until the pressure value is stable and collect pressure data σ 23 , continue rotating and pressurizing by θ angle until the position of testing σ 21 is reached, and the test of the stress of the fault fracture zone at the depth of h2 is completed The test of the stress of the fault fracture zone at this depth is completed, and the above operation is repeated until the pressure values at all depths h1, h2, h3,..., h n that need to be tested in the test hole are measured, and the pressure values σ h1 {σ 11 , σ 12 , σ 13 , σ 14 ... σ 1n} are obtained h2 {σ 21 , σ 22 , σ 23 , σ 24 ... σ 2n} are obtained h3 {σ 31 , σ 32 , σ 33 , σ 34 ... σ 3n} are obtained,..., {σ n1 , σ n2 , σ n3 , σ n4 ... σ nnMeanwhile, the PVC pipe, the hollow connecting rod and the automatic telescopic pressure testing assembly are recycled for use of next testing hole, n = 360° / θ; the vertical stress σ v of the fault fracture zone h , max = γ × h, γ represents the bulk density of rock mass, and h represents the depth of testing; the maximum horizontal stress σ 11 of the fault fracture zone 12 , 13 , 14 … σ 1n}, max{σ 21 , σ 22 , σ 23 , σ 24 … σ 2n}, max{σ 31 , σ 32 , σ 33 , σ 34 … σ 3n}, …, max{σ n1 , σ n2 , σ n3 , σ n4 … σ nn} h , min = min{min{σ 11 , σ 12 , σ 13 , σ 14 … σ 1n}, min{σ 21 , σ 22 , σ 23 , σ 24 … σ 2n}, min{σ 31 , σ 32 , σ 33 , σ 34 … σ 3n}, …, min{σ n1 , σ n2 , σ n3 , σ n4 … σ nn}

[0015] In the second aspect, the diameter of the testing hole is the same as the outer diameter of the PVC pipe; and the θ angle is the same as the angle of the arc-shaped pressure testing piece.

[0016] Beneficial effects:

[0017] Compared with the prior art, the device for measuring the ground stress of a fault fracture zone mainly comprises a PVC pipe, a hollow connecting rod, a hydraulic wire and a pressurizing assembly, the outer diameter of the PVC pipe is consistent with the hole diameter of a test hole, the PVC pipe is used for being inserted into the test hole during the test to prevent the test hole from collapsing and facilitate the placement of the hollow connecting rod and the pressurizing assembly, is suitable for the test of the ground stress of a fault fracture zone, the surface of the PVC pipe needs to be coated with a lubricant to facilitate the placement and extraction of the PVC pipe, and the operation is simple; the hollow connecting rod has a cylindrical structure, a plurality of hollow rod through holes are formed in one end of the hollow connecting rod, the hollow rod through holes are uniformly distributed around the axis of the hollow connecting rod, each hollow rod through hole has a corresponding telescopic hydraulic rod, the top end of the telescopic hydraulic rod passes through the hollow rod through hole and is located in the hollow connecting rod, so that the telescopic hydraulic rod and the hollow connecting rod are connected together; the automatic telescopic pressure test assembly comprises the telescopic hydraulic rod, arc-shaped steel blocks and arc-shaped pressure test pieces, the tail part of the telescopic hydraulic rod is fixedly connected with the arc-shaped steel blocks, the number of the arc-shaped steel blocks is the same as that of the telescopic hydraulic rods, the telescopic hydraulic rods are in groups, each group of the telescopic hydraulic rods is symmetrically distributed with the top end of the telescopic hydraulic rod as the symmetric point, the arc-shaped steel blocks form the peripheral frame of the cylindrical hollow structure by being fixed to the tail part of the telescopic hydraulic rod, the number of the arc-shaped steel blocks is the same as that of the arc-shaped pressure test pieces, the arc-shaped pressure test pieces are fixed to the outer side of the arc-shaped steel blocks, and the arc-shaped pressure test pieces are arranged in close contact with the arc-shaped steel blocks, so that the pressure value measured by the arc-shaped pressure test pieces is more accurate when the arc-shaped steel blocks are subjected to the elongation pressure loading of the telescopic hydraulic rods, meanwhile, the transverse section of the arc-shaped pressure test piece is a circle with the axis of the hollow connecting rod as the center, so that the arc-shaped pressure test piece can be attached to the test hole wall when the telescopic hydraulic rod is elongated under the loading pressure of the loading assembly, the ground stress value data measured by the arc-shaped pressure test piece is more accurate, and the ground stress of the fault fracture zone can be effectively measured. Meanwhile, the automatic telescopic function of the telescopic hydraulic rod facilitates the recycling of the device for measuring the ground stress of a fault fracture zone. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings described in the following only represent some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort based on these drawings.

[0019] Figure 1 is a sectional view of the hollow connecting rod and the automatic telescopic pressure test assembly after being connected in the device for measuring the ground stress of a fault fracture zone of the present application;

[0020] Figure 2is a hollow connecting rod and automatic telescopic pressure testing component connection diagram of a device for measuring the ground stress of a fault fracture zone according to the present application;

[0021] Figure 3 is a schematic diagram of the overall structure of a device for measuring the ground stress of a fault fracture zone according to the present application during use;

[0022] Figure 4 is a schematic diagram of a device for measuring the ground stress of a fault fracture zone according to the present application during use at a depth of h n a test of rotating a θ angle.

[0023] Reference signs:

[0024] 1. PVC pipe;

[0025] 2. Hollow connecting rod; 21. First hollow rod; 22. First round hoop; 23. Second hollow rod; 24. Second round hoop;

[0026] 3. Automatic telescopic pressure testing component; 31. Telescopic hydraulic rod; 32. Arc-shaped steel block; 33. Arc-shaped pressure testing piece; 34. Threaded rod; 35. Testing piece lead hole; 36. Rubber ring;

[0027] 4. Hydraulic lead;

[0028] 5. Pressurizing component;

[0029] 6. Data acquisition system. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present specification will be described clearly and completely below in combination with the drawings in the embodiments of the present specification. Obviously, the described embodiments are only some of the embodiments of the present specification, not all the embodiments. Based on the embodiments in the present specification, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0031] Embodiment one

[0032] As Figures 1 to 3The embodiment one provides a device for measuring the ground stress of a fault fracture zone, which comprises a PVC pipe 1, a hollow connecting rod 2, which is in a cylindrical structure, has a plurality of hollow rod through holes at one end, and has the plurality of hollow rod through holes evenly distributed on the side wall of the hollow connecting rod 2 with the center axis of the hollow connecting rod 2 as the axis, and is located inside the PVC pipe 1, an automatic telescopic pressure test assembly 3, which comprises a plurality of telescopic hydraulic rods 31, a plurality of arc-shaped steel blocks 32, and a plurality of arc-shaped pressure test pieces 33, wherein the number of the plurality of telescopic hydraulic rods 31 is matched with the number of the plurality of hollow rod through holes, the number of the plurality of arc-shaped steel blocks 32 is matched with the number of the plurality of telescopic hydraulic rods, and the number of the plurality of arc-shaped pressure test pieces 33 is matched with the number of the plurality of arc-shaped steel blocks, each of the hollow rod through holes and each of the telescopic hydraulic rods 31 is one-to-one corresponding, the top of each of the telescopic hydraulic rods 31 penetrates through a corresponding hollow rod through hole, and the top of the telescopic hydraulic rod 31 is located in the hollow connecting rod 2, each of the telescopic hydraulic rods 31 is fixedly connected with a corresponding arc-shaped steel block 32, each of the arc-shaped steel blocks 32 is fixedly connected with a corresponding arc-shaped pressure test piece 33, the plurality of telescopic hydraulic rods 31, the plurality of arc-shaped steel blocks 32, and the plurality of arc-shaped pressure test pieces 33 are all located in the PVC pipe 1, a plurality of hydraulic wires 4 are matched with the number of the plurality of telescopic hydraulic rods 31, one end of each of the hydraulic wires 4 is connected with a corresponding telescopic hydraulic rod 31, a pressurizing assembly 5 is connected with the other end of the plurality of hydraulic wires 4, and each of the telescopic hydraulic rods 31 and a corresponding arc-shaped steel block 32 are provided with a hydraulic interface at the connecting end.

[0033] Compared with the prior art, the device for measuring the ground stress of a fault fracture zone mainly comprises a PVC pipe, a hollow connecting rod, a hydraulic wire and a pressurizing assembly, the outer diameter of the PVC pipe is consistent with the hole diameter of a test hole, the PVC pipe is used for being inserted into the test hole during the test process to prevent the test hole from collapsing and facilitate the placement of the hollow connecting rod and the pressurizing assembly, is suitable for the test of the ground stress of a fault fracture zone, and the surface of the PVC pipe needs to be coated with a lubricant to facilitate the placement and extraction of the PVC pipe and is simple to operate; the hollow connecting rod has a cylindrical structure, a plurality of hollow rod through holes are formed in one end of the hollow connecting rod, the hollow rod through holes are uniformly distributed around the axis of the hollow connecting rod, each hollow rod through hole has a corresponding telescopic hydraulic rod, the top end of the telescopic hydraulic rod passes through the hollow rod through hole and is located in the hollow connecting rod, so that the telescopic hydraulic rod and the hollow connecting rod are connected together; the automatic telescopic pressure test assembly comprises the telescopic hydraulic rod, arc-shaped steel blocks and arc-shaped pressure test pieces, the tail part of the telescopic hydraulic rod is fixedly connected with the arc-shaped steel blocks, the number of the arc-shaped steel blocks is the same as that of the telescopic hydraulic rods, the telescopic hydraulic rods are grouped into two, and each group of telescopic hydraulic rods is symmetrically distributed with the top end of the telescopic hydraulic rod as the symmetric point; the arc-shaped steel blocks form a peripheral frame of the cylindrical hollow structure by being fixed to the tail part of the telescopic hydraulic rod, the number of the arc-shaped steel blocks is the same as that of the arc-shaped pressure test pieces, the arc-shaped pressure test pieces are fixed to the outer side of the arc-shaped steel blocks, and the arc-shaped pressure test pieces are arranged in close contact with the arc-shaped steel blocks, so that the pressure value measured by the arc-shaped pressure test pieces is more accurate when the arc-shaped steel blocks are subjected to the elongation pressure loading of the telescopic hydraulic rods; meanwhile, the cross section of the arc-shaped pressure test piece is a circle with the axis of the hollow connecting rod as the center, so that the arc-shaped pressure test piece can be attached to the test hole wall when the telescopic hydraulic rod is elongated under the loading pressure of the loading assembly, and the ground stress value data measured by the arc-shaped pressure test piece is more accurate, so that the ground stress of the fault fracture zone can be effectively measured. Meanwhile, the automatic telescopic function of the telescopic hydraulic rod facilitates the recycling of the device for measuring the ground stress of a fault fracture zone.

[0034] In some possible implementation manners, a hydraulic threaded hole is formed in the inner side center of each arc-shaped steel block 32, the tail part of each telescopic hydraulic rod 31 is in a threaded form, and the tail part of each telescopic hydraulic rod 31 is matched with a corresponding hydraulic threaded hole; a test piece threaded hole is formed in the outer side center of each arc-shaped steel block 32, and a threaded rod 34 is arranged at the center position of each arc-shaped pressure test piece, each threaded rod 34 is matched with each test piece threaded hole.

[0035] Specifically, a hydraulic threaded hole is arranged at the center of the inner side of the arc-shaped steel block, and the tail of the telescopic hydraulic rod is threaded, so that the telescopic hydraulic rod is threadedly connected with the arc-shaped steel block and can be disassembled after use; a test piece threaded hole is arranged at the center of the outer side of the arc-shaped steel block, and a threaded rod is fixed at the center of the arc-shaped pressure test piece, so that the arc-shaped arc-shaped steel block and the arc-shaped pressure test piece are threadedly connected through the threaded rod and the test piece threaded hole and can be disassembled after use.

[0036] In some possible implementation manners, the hollow connecting rod 2 comprises: a first hollow rod 21, the first hollow rod 21 comprising two first semicircular steel pipes, the two first semicircular steel pipes being spliced into a cylindrical structure through a first circular hoop 22, an inner side of one end of the first hollow rod 21 being threaded; a second hollow rod 23, the second hollow rod 23 comprising two second semicircular steel pipes, the two second semicircular steel pipes being spliced into a cylindrical structure through a second circular hoop 24, an outer side of one end of the second hollow rod 23 being threaded; wherein the inner diameter length of the first hollow rod 21 is the same as the outer diameter length of the second hollow rod 23, and the first hollow rod 21 is threadedly connected with the second hollow rod 23; the other end of the second hollow rod 23 is provided with the plurality of hollow rod through holes, the plurality of hollow rod through holes being uniformly distributed on the side wall of the second hollow rod 23 with the center axis of the second hollow rod 23 as an axis, and the top of the telescopic hydraulic rod 31 is located in the second hollow rod 23; a threading hole is arranged on one side of the side wall of the second hollow rod 23 corresponding to each telescopic hydraulic rod 31, and the other end of each hydraulic wire 4 is sequentially connected with the pressurizing assembly 5 through the corresponding threading hole, the second hollow rod 23, the first hollow rod 21 and the pressurizing assembly 5.

[0037] Specifically, the hollow connecting rod is divided into two sections, namely a first hollow rod and a second hollow rod. The first hollow rod is formed into a cylindrical structure by two first semicircular steel pipes fixed by a plurality of first circular hoops, and is threaded on the inner side of one end of the first hollow rod. The second hollow rod is formed into a cylindrical structure by two second semicircular steel pipes fixed by a plurality of second circular hoops, and is threaded on the outer side of one end of the second hollow rod. Meanwhile, the inner diameter of the first hollow rod is equal to the outer diameter of the second hollow rod, so that the first hollow rod and the second hollow rod are threadedly connected, and the hollow connecting rod can be disassembled and placed to reduce the occupied space when not in use. In addition, during the assembly of the hollow connecting rod and the automatic telescopic pressure testing assembly, since the second hollow connecting rod is formed by two second semicircular steel pipes fixed by a plurality of second circular hoops, the telescopic hydraulic rod can first pass through the hollow rod through hole on the second hollow pipe, then the two second semicircular steel pipes are fixed by the second circular hoops, and then the telescopic hydraulic rod and the arc-shaped steel block are screw-fixed, so that the device for measuring the stress of the fault fracture zone is more convenient to assemble. The purpose of the threading hole on one side of each telescopic hydraulic rod on the second hollow rod is to make the hydraulic lead and the arc-shaped pressure testing piece lead pass into the second hollow rod and the first hollow rod, and then be connected with the loading assembly and the data acquisition system, respectively.

[0038] In some possible implementations, the device for measuring the stress of the fault fracture zone further includes a data acquisition system 6, wherein the top of each telescopic hydraulic rod 31 is provided with a displacement sensor, and each displacement sensor is connected with the data acquisition system 6.

[0039] Specifically, the data acquisition system is used to collect the test data of the displacement sensor and the arc-shaped pressure testing piece. The displacement sensor is located on one side of the top of the telescopic hydraulic rod, and is used to measure the length of the telescopic hydraulic rod when the arc-shaped pressure testing piece is close to the hole wall of the test hole, and measure the vertical distance between the first test point or region and another test point or region during the test. The displacement sensor lead is led out from the inside of the hollow connecting rod, so as to avoid the influence of the sensor lead on the device test process.

[0040] In some possible implementations, the automatic expansion pressure testing assembly further includes: a plurality of groups of arc-shaped pressure testing piece wires, one end of each group of the arc-shaped pressure testing piece wires being connected with a corresponding one of the arc-shaped pressure testing pieces 33; each group of the arc-shaped pressure testing piece wires includes two arc-shaped pressure testing piece wires, one end of one of the arc-shaped pressure testing piece wires being connected with one end of a corresponding one of the arc-shaped pressure testing pieces 33, and one end of the other arc-shaped pressure testing piece wire being connected with the other end of the corresponding one of the arc-shaped pressure testing pieces; a plurality of groups of testing piece wire holes 35 corresponding to the number of groups of the arc-shaped pressure testing piece wires, one group of the testing piece wire holes 35 being arranged on each of the arc-shaped steel blocks 32, and each group of the testing piece wire holes 35 including two of the testing piece wire holes 35; the connection points of each of the arc-shaped pressure testing piece wires and the corresponding arc-shaped pressure testing piece 33 are distributed one-to-one with each of the testing piece wire holes 35, and each of the testing piece wire holes 35 is adapted to each of the arc-shaped pressure testing piece wires; wherein one end of each of the arc-shaped pressure testing piece wires is connected with the corresponding one of the arc-shaped pressure testing pieces 33, and the other end of each of the arc-shaped pressure testing piece wires is sequentially connected with the data acquisition system 6 through the corresponding testing piece wire hole 35, the corresponding threading hole, the second hollow rod 23, and the first hollow rod 21.

[0041] Specifically, two ends of each arc-shaped pressure testing piece are respectively connected with two arc-shaped pressure piece wires, each arc-shaped pressure testing piece wire needs to be electrically connected with the data acquisition system, a testing piece wire hole is arranged on the arc-shaped steel block, and the position of each testing piece wire hole corresponds to the interface position of the arc-shaped testing piece wire on the arc-shaped testing piece one-to-one, so that the influence of the arc-shaped pressure testing piece wire on the ground stress test in the arc-shaped pressure testing piece area during the test is excluded, and the ground stress measured by the arc-shaped pressure testing piece is more accurate.

[0042] In some possible implementation manners, the automatic telescopic pressure testing assembly further comprises a rubber ring 36 in a cylindrical hollow structure, a plurality of threaded holes are formed in the cylinder of the rubber ring 36, and each threaded rod 34 is distributed in one-to-one correspondence with each threaded hole. The rubber ring 36 is sleeved on the plurality of arc-shaped steel blocks 32 to cover the plurality of arc-shaped steel blocks 32 and the plurality of telescopic hydraulic rods 31. The rubber ring 36 is located between each arc-shaped steel block 32 and each arc-shaped pressure testing piece 33, and each threaded rod 34 is connected with a corresponding arc-shaped steel block 32 by penetrating through the corresponding threaded hole. Two hollow rod through holes are symmetrically formed at two ends of the rubber ring 36, and the other end of the second hollow rod 23 penetrates through the two hollow through holes in sequence, and the two hollow rod through holes are in close contact with the outer side wall of the second hollow rod 23.

[0043] Specifically, when the second hollow rod, the telescopic hydraulic rod and the arc-shaped steel block are assembled, a cylindrical frame is formed. The rubber ring is sleeved on the arc-shaped steel block to further form a closed cylindrical structure. The hollow rod through holes are formed at two ends of the rubber ring, and the second hollow rod can penetrate through the hollow rod through holes, so that the space between the pipe wall of the second hollow rod and the arc-shaped steel block is in a closed state, thereby avoiding the influence of the falling of the gravel in the test hole on the telescopic hydraulic rod, and avoiding the influence on the ground stress testing process. The threaded holes formed in the side wall of the rubber ring are used for the threaded rods to penetrate through the arc-shaped steel block and the arc-shaped pressure testing piece.

[0044] In some possible implementation manners, the number of the telescopic hydraulic rods 31 is 4, and the central axis of the arc-shaped pressure testing piece 33 is on the same straight line as the central axis of the first hollow rod 21 and / or the second hollow rod 23.

[0045] Specifically, the two telescopic hydraulic rods of each group are perpendicular to the central axis of the second hollow rod and are symmetrically distributed with the central axis of the second hollow rod as the axis of symmetry. The telescopic hydraulic rod is 4, so that the telescopic hydraulic rod is divided into two groups, and the two groups of telescopic hydraulic rods are perpendicular to each other in a straight line, so that the four telescopic hydraulic rods are more fully utilized when elongated under the action of the loading assembly, and the test of the ground stress is more accurate. The arc-shaped pressure testing piece shares one central axis with the first hollow rod and the second hollow rod, and simultaneously shares one central axis with the test hole, so that the arc-shaped pressure testing piece can completely adhere to the hole wall of the test hole, and the test of the fault fracture zone ground stress is more accurate and effective. In addition, the arc-shaped pressure testing piece has a plurality of specifications, which can be selected according to specific test requirements, is convenient to replace, and makes the use range of the device for measuring the fault fracture zone ground stress larger.

[0046] Embodiment two

[0047] As Figure 3 and Figure 4 shown, the second embodiment of the application provides a method for using a device for measuring the ground stress of a fault fracture zone, which is used for the device for measuring the ground stress of a fault fracture zone in the first embodiment, the method comprising: determining the drilling position of the fault fracture zone through local collection of geological data and on-site investigation, drilling a test hole with a diameter of d and a depth of h at the determined drilling position, when there is no design specification, the final hole position deviation is not more than 10 cm, and the hole deviation error is not more than 2%; smearing lubricant on the surface of a PVC pipe and placing it in the test hole; assembling a hollow connecting rod and assembling the hollow connecting rod with an automatic telescopic pressure testing assembly, connecting the hydraulic wire with the pressurizing assembly through the hollow connecting rod, and respectively connecting the displacement sensor wire and the arc-shaped pressure testing piece wire with the data acquisition system after passing through the hollow connecting rod; then placing the assembled hollow connecting rod and the automatic telescopic pressure testing assembly into the PVC pipe to the designed test depth; at the test depth h1, pulling out the PVC pipe until the automatic telescopic pressure testing assembly is completely exposed from the PVC pipe, opening the data acquisition system to start real-time monitoring of pressure data, starting the pressurizing assembly to make the telescopic hydraulic rod elongate to pressurize the arc-shaped steel block and the arc-shaped pressure testing piece, and making the arc-shaped pressure testing piece tightly adhere to the test hole wall; when the tested pressure value is stable, stopping the collection of pressure data and pressurization, and the collected pressure data is σ 11 , then rotating the automatic telescopic pressure testing assembly by θ angle, continuing to pressurize until the pressure value is stable and collecting pressure data σ 12 , then stopping the collection of pressure data and pressurization, and then continuing to rotate by θ angle and continuing to pressurize until the pressure value is stable and collecting pressure data σ 13 , continuing to rotate and pressurize by θ angle until rotating to the position of testing σ 11 , completing the test of the ground stress of the fault fracture zone at the depth h1; then the telescopic hydraulic rod is retracted, the assembled hollow connecting rod and the automatic telescopic pressure testing assembly are lifted to a new test depth h2, and the PVC pipe is continuously pulled out until the automatic telescopic pressure testing assembly is completely exposed from the PVC pipe, then the telescopic hydraulic rod is elongated by the pressurizing assembly to pressurize the arc-shaped steel block and the arc-shaped pressure testing piece, and the arc-shaped pressure testing piece tightly adheres to the test hole wall; when the tested pressure value is stable, stopping the collection of pressure data and pressurization, and the collected pressure data is σ 21 , then rotating the automatic telescopic pressure testing assembly by θ angle, continuing to pressurize until the pressure value is stable and collecting pressure data σ 22 , then stopping the collection of pressure data and pressurization, and then continuing to rotate by θ angle and continuing to pressurize until the pressure value is stable and collecting pressure data σ23 , continue to rotate the pressure measurement by θ angle, until the rotation to the position of the test σ 21 , complete the test of the fault fracture zone ground stress under h2 depth, complete the test of the fault fracture zone ground stress under this depth, repeat the above operation until the pressure value under all depths h1, h2, h3, …, h n of the test hole that need to be tested is measured, and the pressure value σ h1 {σ 11 , σ 12 , σ 13 , σ 14 …σ 1n} is obtained, σ h2 {σ 21 , σ 22 , σ 23 , σ 24 …σ 2n} is obtained, σ h3 {σ 31 , σ 32 , σ 33 , σ 34 …σ 3n} is obtained, …, σ n1 {σ n2 , σ n3 , σ n4 , σ nn …σ v} is obtained; meanwhile, the PVC pipe, the hollow connecting rod and the automatic telescopic pressure test assembly are recovered for use in the next test hole, and n = 360° / θ; the vertical ground stress σ h of the fault fracture zone = γ×h, γ represents the bulk density of the rock mass, and h represents the test depth; the maximum horizontal ground stress σ max of the fault fracture zone = max{max{σ 11 , σ 12 , σ 13 , σ 14 …σ 1n}, max{σ 21 , σ 22 , σ 23 , σ 24 …σ 2n}, max{σ 31 , σ 32 , σ 33 , σ 34 …σ 3n}, …, max{σ n1 , σ n2 , σ n3 , σ n4 …σ nnthe minimum horizontal ground stress σ h , min = min{min{σ 11 , σ 12 , σ 13 , σ 14 ... σ 1n}, min{σ 21 , σ 22 , σ 23 , σ 24 ... σ 2n}, min{σ 31 , σ 32 , σ 33 , σ 34 ... σ 3n},..., min{σ n1 , σ n2 , σ n3 , σ n4 ... σ nn}} and the direction of the maximum horizontal ground stress and the minimum horizontal ground stress are determined according to the rotation angle θ in the test step; the diameter of the test hole is the same as the outer diameter of the PVC pipe; the θ angle is the same as the angle of the arc-shaped pressure test piece.

[0048] Specifically, in the process of testing the ground stress of the fault fracture zone by using the device for measuring the ground stress of the fault fracture zone, the drilling position of the fault fracture zone to be tested is determined first, and a test hole with a diameter of d and a depth of h is drilled. The test hole needs to be in a vertical state, and the hole deviation error should not exceed 2% to avoid causing errors in subsequent ground stress testing. Meanwhile, the deviation between the formed hole position and the determined drilling position should not exceed 10 cm, which affects the acquisition of the ground stress value of the required position. After drilling the test hole at the required testing position, a PVC pipe is placed in the test hole. The outer diameter of the PVC pipe is the same as the diameter of the test hole, so that the PVC pipe can tightly adhere to the hole wall of the test hole and support the hole wall of the test hole to prevent the test hole from collapsing. Meanwhile, it is convenient for the automatic telescopic pressure testing assembly to be placed in the test hole before testing, which avoids the test hole collapsing or the hole wall falling during the process of placing the automatic telescopic pressure testing assembly. Before placing the PVC pipe in the test hole, a lubricant needs to be applied to the outer surface of the PVC pipe to reduce the friction between the PVC pipe and the test hole and facilitate the placement of the PVC pipe in the test hole. The assembled hollow connecting rod and automatic telescopic pressure testing assembly are placed in the test hole through the PVC pipe, and are first placed to the deepest testing depth h1 of the test hole. Then, the PVC pipe is pulled upward along the vertical direction of the test hole to expose the automatic telescopic pressure testing assembly, so that the automatic telescopic pressure testing assembly is completely exposed in the test hole. This enables the arc-shaped pressure testing piece to directly contact the hole wall of the test hole in the subsequent testing process, so that the measured ground stress test result is more accurate. Then, the pressurizing assembly is turned on to elongate the telescopic hydraulic rod. The arc-shaped pressure testing piece is completely attached to the hole wall of the test hole through the elongation of the four telescopic hydraulic rods. In the process of elongating the telescopic hydraulic rod to press the arc-shaped pressure testing piece against the hole wall of the test hole, the data acquisition system monitors the pressure data values measured by the four arc-shaped pressure testing pieces. When it is monitored that the pressure data values of the four arc-shaped pressure testing pieces remain consistent and stable, the pressure value σ 11 is recorded. Then, the pressurizing assembly stops pressurizing the telescopic hydraulic rod, and the telescopic hydraulic rod is retracted. The automatic telescopic pressure testing assembly is rotated at the same depth by an angle of θ. Then, the pressurizing assembly is turned on again to pressurize the telescopic hydraulic rod. The telescopic hydraulic rod is elongated to press the arc-shaped pressure testing piece against the hole wall of the test hole. The data acquisition system monitors the pressure data values measured by the four arc-shaped pressure testing pieces. When it is monitored that the pressure data values of the four arc-shaped pressure testing pieces remain consistent and stable, the pressure value σ 12 is recorded. Then, the pressurizing assembly stops pressurizing the telescopic hydraulic rod, and the telescopic hydraulic rod is retracted. The automatic telescopic pressure testing assembly is continuously rotated by an angle of θ. Then, the pressurizing assembly is turned on again to pressurize the telescopic hydraulic rod. The telescopic hydraulic rod is elongated to press the arc-shaped pressure testing piece against the hole wall of the test hole. The data acquisition system monitors the pressure data values measured by the four arc-shaped pressure testing pieces. When it is monitored that the pressure data values of the four arc-shaped pressure testing pieces remain consistent and stable, the pressure value σ is recorded.13 Then stop the pressurizing assembly to pressurize the telescopic hydraulic rod, the telescopic hydraulic rod is retracted, and the above operation is repeated until the rotation to the test σ 11 position is completed, the in-situ stress test at the depth h1 is completed; then the automatic telescopic pressure test assembly is lifted upward along the vertical direction of the test hole to a new test depth h2, and then the PVC pipe is pulled upward until the automatic telescopic pressure test assembly is fully exposed from the PVC pipe again, the test process at the depth h1 is repeated, until the in-situ stress test at all depths h1, h2, h3, …, h n is completed in the test hole, the data acquisition system collects the in-situ stress pressure values σ h1 {σ 11 , σ 12 , σ 13 , σ 14 …σ 1n} measured by the arc-shaped pressure test pieces at the corresponding depths. h2 {σ 21 , σ 22 , σ 23 , σ 24 …σ 2n} measured by the arc-shaped pressure test pieces at the corresponding depths. h3 {σ 31 , σ 32 , σ 33 , σ 34 …σ 3n} measured by the arc-shaped pressure test pieces at the corresponding depths. n1 , σ n2 , σ n3 , σ n4 …σ nn} measured by the arc-shaped pressure test pieces at the corresponding depths. h , max = max{max{σ 11 , σ 12 , σ 13 , σ 14 …σ 1n} measured by the arc-shaped pressure test pieces at the corresponding depths. 21 , σ 22 , σ 23 , σ 24 …σ 2n} measured by the arc-shaped pressure test pieces at the corresponding depths. 31 , σ 32 , σ 33 , σ 34 …σ 3n} measured by the arc-shaped pressure test pieces at the corresponding depths. n1 , σ n2 , σ n3 , σ n4 …σ nn}}; and the minimum horizontal stress of the fault fracture zone h , min = min{min{σ 11 , σ 12 , σ 13 , σ 14 ... σ 1n}, min{σ 21 , σ 22 , σ 23 , σ 24 ... σ 2n}, min{σ 31 , σ 32 , σ 33 , σ 34 ... σ 3n},..., min{σ n1 , σ n2 , σ n3 , σ n4 ... σ nn}}, n = 360° / θ, in addition, the rock bulk density γ of the test point is tested by drilling a test hole, and the point depth h is tested by the arc-shaped pressure testing piece, so as to obtain the vertical stress σ v = γ x h of the fault fracture zone, and the ground stress of the fault fracture zone obtained by the method is accurate.

[0049] Those skilled in the art can understand that, due to the use of the method for measuring the ground stress of the fault fracture zone of the device of embodiment two, the performance principle of the device for measuring the ground stress of the fault fracture zone of embodiment one is not described here, and the part not described can be referred to embodiment one.

[0050] The preferred embodiments of the present application are described in detail above. It should be understood that those skilled in the art can make many modifications and changes without creative labor according to the concept of the present application. Therefore, any technical solution obtained by logical analysis, reasoning or limited experiment on the basis of the prior art according to the concept of the present application shall be within the protection scope determined by the claims.

Claims

1. A device for measuring ground stress in fault fracture zones, characterized in that, The device for measuring the ground stress in the fault fracture zone includes: PVC pipe (1); Hollow connecting rod (2), the hollow connecting rod (2) has a cylindrical structure, and a plurality of hollow rod through holes are opened at one end of the hollow connecting rod (2). The plurality of hollow rod through holes are evenly distributed on the side wall of the hollow connecting rod (2) with the central axis of the hollow connecting rod (2) as the axis. The hollow connecting rod (2) is located inside the PVC pipe (1). An automatic telescopic pressure testing assembly (3) includes several telescopic hydraulic rods (31) adapted to the number of the several hollow rod through holes, several arc-shaped steel blocks (32) adapted to the number of the several telescopic hydraulic rods, and several arc-shaped pressure testing plates (33) adapted to the number of the several arc-shaped steel blocks; each hollow rod through hole corresponds to each telescopic hydraulic rod (31), and the top of each telescopic hydraulic rod (31) passes through the corresponding... The hollow rod has a through hole, and the top of the telescopic hydraulic rod (31) is located inside the hollow connecting rod (2); each telescopic hydraulic rod (31) is fixedly connected to a corresponding arc-shaped steel block (32); each arc-shaped steel block (32) is fixedly connected to a corresponding arc-shaped pressure test piece (33); several telescopic hydraulic rods (31), several arc-shaped steel blocks (32) and several arc-shaped pressure test pieces (33) are all located inside the PVC pipe (1); A plurality of hydraulic wires (4) adapted to the number of the plurality of retractable hydraulic rods (31), one end of each of the hydraulic wires (4) being connected to a corresponding retractable hydraulic rod (31); A pressurizing assembly (5), one end of which is connected to the other end of a plurality of hydraulic wires (4); Each of the retractable hydraulic rods (31) is provided with a hydraulic interface at the connection end with the corresponding distributed arc-shaped steel blocks (32), and one end of each hydraulic wire (4) is connected to the corresponding hydraulic interface.

2. The device for measuring ground stress in fault fracture zones as described in claim 1, characterized in that: Each of the arc-shaped steel blocks (32) has a hydraulic threaded hole at its inner center, and the tail of each of the telescopic hydraulic rods (31) is threaded, with the tail of each of the telescopic hydraulic rods (31) matching a corresponding hydraulic threaded hole; each of the arc-shaped steel blocks (32) has a test piece threaded hole at its outer center, and a threaded rod (34) is provided at the center of each of the arc-shaped pressure test pieces, with each threaded rod (34) matching a threaded hole of each of the test pieces.

3. The device for measuring ground stress in fault fracture zones as described in claim 2, characterized in that, The hollow connecting rod (2) includes: The first hollow rod (21) includes two first semi-circular steel pipes. The two first semi-circular steel pipes are spliced ​​together by a first circular hoop (22) to form a cylindrical structure. The inner side of one end of the first hollow rod (21) is threaded. The second hollow rod (23) includes two second semi-circular steel pipes. The two second semi-circular steel pipes are spliced ​​together by a second circular hoop (24) to form a cylindrical structure. The outer side of one end of the second hollow rod (23) is threaded. The inner diameter of the first hollow rod (21) is the same as the outer diameter of the second hollow rod (23), and the first hollow rod (21) and the second hollow rod (23) are threaded together. The other end of the second hollow rod (23) is provided with a plurality of hollow rod through holes, which are evenly distributed on the side wall of the second hollow rod (23) with the central axis of the second hollow rod (23) as the axis. The top of the telescopic hydraulic rod (31) is located inside the second hollow rod (23). A wire hole is provided on one side wall of each telescopic hydraulic rod (31) on the second hollow rod (23), and the other end of each hydraulic wire (4) passes through the corresponding wire hole, the second hollow rod (23), the first hollow rod (21) and is connected to the pressurizing component (5).

4. The device for measuring ground stress in fault fracture zones as described in claim 3, characterized in that: The device for measuring the ground stress in the fault fracture zone also includes a data acquisition system (6), wherein a displacement sensor is provided on the top of each of the telescopic hydraulic rods (31), and each of the displacement sensors is connected to the data acquisition system (6).

5. The device for measuring ground stress in fault fracture zones as described in claim 4, characterized in that, The automatic expansion and contraction pressure testing component also includes: Several sets of arc-shaped pressure test strip wires, one end of each set of arc-shaped pressure test strip wires is connected to a corresponding arc-shaped pressure test strip (33); each set of arc-shaped pressure test strip wires includes two arc-shaped pressure test strip wires, one end of one arc-shaped pressure test strip wire is connected to one end of a corresponding arc-shaped pressure test strip (33), and one end of the other arc-shaped pressure test strip wire is connected to the other end of a corresponding arc-shaped pressure test strip; A plurality of test piece wire holes (35) are provided to match the number of sets of the arc-shaped pressure test piece wires. Each arc-shaped steel block (32) has a set of test piece wire holes (35), and each set of test piece wire holes (35) includes two test piece wire holes (35). The connection point between each arc-shaped pressure test piece wire and the corresponding arc-shaped pressure test piece (33) is distributed one-to-one with each test piece wire hole (35), and each test piece wire hole (35) is matched with each arc-shaped pressure test piece wire. One end of the wire of each of the arc-shaped pressure test pieces is connected to the corresponding arc-shaped pressure test piece (33), and the other end of the wire of each of the arc-shaped pressure test pieces passes through the corresponding test piece wire hole (35), the corresponding wire hole, the second hollow rod (23) and the first hollow rod (21) in sequence and is connected to the data acquisition system (6).

6. The device for measuring ground stress in fault fracture zones as described in claim 5, characterized in that, The automatic expansion and contraction pressure testing component also includes: A rubber ring (36) has a cylindrical hollow structure. The cylindrical body of the rubber ring (36) has several threaded holes that match the number of the several threaded rods (34). Each threaded rod (34) is distributed in a one-to-one correspondence with each threaded hole. The rubber ring (36) is fitted on several arc-shaped steel blocks (32) to cover the several arc-shaped steel blocks (32) and several telescopic hydraulic rods (31). The rubber ring (36) is located between each arc-shaped steel block (32) and each arc-shaped pressure test piece (33). Each threaded rod (34) passes through the corresponding threaded hole and connects to the corresponding arc-shaped steel block (32). The rubber ring (36) has two hollow rod through holes symmetrically opened at both ends. The other end of the second hollow rod (23) passes through the two hollow through holes in sequence, and the two hollow rod through holes are close to the outer side wall of the second hollow rod (23).

7. The device for measuring ground stress in fault fracture zones as described in claim 6, characterized in that: The number of the retractable hydraulic rods (31) is 4.

8. The device for measuring ground stress in fault fracture zones as described in claim 7, characterized in that: The central axis of the arc-shaped pressure test piece (33) is on the same straight line as the central axis of the first hollow rod (21) and / or the second hollow rod (23).

9. A method of using an apparatus for measuring ground stress in a fault fracture zone, for use with any of the apparatuses described in claims 1-8, characterized in that, The method of use includes: Based on locally collected geological data and on-site investigation, the drilling location of the fault fracture zone was determined. Drilling equipment was used to drill at the located drilling location, and test holes with a diameter of d and a depth of h were drilled. In the absence of design specifications, the final hole position deviation should not exceed 10cm, and the hole inclination error should not exceed 2%. Apply lubricant to the surface of the PVC pipe and place it in the test hole; assemble the hollow connecting rod and assemble the hollow connecting rod with the automatic telescopic pressure testing assembly; pass the hydraulic wire through the hollow connecting rod and connect it to the pressurization assembly; pass the displacement sensor wire and the arc-shaped pressure test piece wire through the hollow connecting rod and then electrically connect them to the data acquisition system; then place the assembled hollow connecting rod and the automatic telescopic pressure testing assembly into the PVC pipe to the designed test depth; At a test depth of h1, the PVC pipe is pulled until the automatic telescopic pressure testing assembly fully exposes the PVC pipe. The data acquisition system is then activated to begin real-time monitoring of pressure data. The pressurization assembly is activated to extend the telescopic hydraulic rod and apply pressure to the arc-shaped steel block and the arc-shaped pressure test piece, ensuring that the arc-shaped pressure test piece is tightly fitted against the test hole wall. Once the measured pressure value stabilizes, pressure data acquisition and pressurization are stopped. The acquired pressure data is σ. 11 Then, the automatic telescopic pressure testing component is rotated by an angle θ, and pressure is continued to be applied until the pressure value stabilizes and pressure data σ is collected. 12 Then stop collecting pressure data and increasing pressure, then continue rotating by angle θ and continuing to increase pressure until the pressure value stabilizes and collect pressure data σ. 13，继续按θ角度旋转加压测压，直至旋转至测试σ11 At the location h1, the stress in the fault fracture zone is tested. Then, the retractable hydraulic rod retracts, lifting the assembled hollow connecting rod and the automatic retractable pressure testing assembly to a new testing depth h2. Simultaneously, the PVC pipe is pulled until the automatic retractable pressure testing assembly is fully exposed. Then, the retractable hydraulic rod extends through the pressurizing assembly to pressurize the arc-shaped steel block and the arc-shaped pressure test piece, ensuring the arc-shaped pressure test piece is tightly against the test hole wall. Once the pressure value obtained during the test stabilizes, pressure data acquisition and pressurization are stopped. The acquired pressure data is σ. 21 Then, the automatic telescopic pressure testing component is rotated by an angle θ, and pressure is continued to be applied until the pressure value stabilizes and pressure data σ is collected. 22 Then stop collecting pressure data and increasing pressure, then continue rotating by angle θ and continuing to increase pressure until the pressure value stabilizes and collect pressure data σ. 23 Continue rotating by angle θ to apply pressure and measure the pressure until the test value σ is reached. 21 At the location h2, complete the test of the ground stress in the fault fracture zone at this depth. Repeat the above operation until all depths h1, h2, h3, ..., h2 in the test borehole have been measured. n The pressure value at the corresponding depth is used to obtain the pressure value σ measured by the arc-shaped pressure test piece. h1 {σ 11 , σ 12 , σ 13，σ14 …σ 1n }, σ h2 {σ 21 , σ 22 , σ 23 , σ 24…σ2n }, σ h3 {σ 31 , σ 32 , σ 33 , σ 34 …σ 3n}，.....，{σn1 , σ n2 , σ n3 , σ n4 …σ nn Simultaneously, the PVC pipe, the hollow connecting rod, and the automatic telescopic pressure testing assembly are recycled for use in the next test hole, where n = 360° / θ. Vertical stress in the fault fracture zone γ represents the unit weight of the rock mass, and h represents the depth of the test; the maximum horizontal in-situ stress σ in the fault fracture zone. h , max =max{max{σ 11 , σ 12 , σ 13 , σ 14 …σ 1n }, max{σ 21，σ22 , σ 23 , σ 24 …σ 2n }, max{σ 31 , σ 32，σ33 , σ 34 …σ 3n },…,max{σ n1 , σ n2 , σ n3，σn4 …σ nn The minimum horizontal stress σ in the fault fracture zone h , min =min{min{σ 11 , σ 12 , σ 13 , σ 14…σ1n }, min{σ 21 , σ 22 , σ 23 , σ 24 …σ 2n}，min{σ31 , σ 32 , σ 33 , σ 34 …σ 3n },…,min{σ n1，σn2 , σ n3 , σ n4 …σ nn Meanwhile, the directions of the maximum and minimum horizontal ground stresses are determined based on the rotation angle θ in the test steps.

10. The method of using the apparatus for measuring ground stress in fault fracture zones as described in claim 9, characterized in that: The diameter of the test hole is the same as the outer diameter of the PVC pipe; the angle θ is the same as the angle of the arc-shaped pressure test piece.

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