Rock mass strength in-situ accurate test system and method

Abstract

The invention discloses a rock mass strength in-situ accurate test system and method, relates to the technical field of original rock mass compressive strength, and solves the problem that in-situ accurate measurement of the shear strength of a rock mass cannot be realized in the prior art. The device comprises a drill hole annular cutting device used for forming a double-position annular cutting groove in a drill hole in a rock mass, and an in-situ strength testing system used for being arranged at the double-position annular cutting groove. The drilling and girdling device comprises a drill body, a girdling cutter and an adjusting mechanism are arranged in the drill body, and the adjusting mechanism is matched with the girdling cutter and can control the girdling cutter to extend out of or retract into the drill body perpendicular to the drill body; the in-situ strength testing system comprises a supply assembly, the supply assembly is connected with a bidirectional air bag assembly, and the bidirectional air bag assembly is arranged on a supporting frame; a test rock body is formed on the rock body between the two-position annular cutting grooves, and the supporting frame is used for placing the two-way air bag assembly into the two-position annular cutting grooves and is matched with the test rock body. The test rock mass formed by the system is standard in specification and few in error inducement, so that the measurement result is more accurate, and the reliability is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of original rock mass compressive strength, and in particular to an in-situ precise testing system and method for rock mass strength. Background Art

[0002] Rock mass mechanics parameters include uniaxial compressive strength, uniaxial tensile strength, shear strength and triaxial compressive strength, etc. They are the most basic parameters in geotechnical, coal and other engineering research, and are essential basic parameters for studying tunnel excavation and support, mine construction, etc.

[0003] At present, the main methods for on-site strength testing include large-scale direct shear tests, strength tests based on ultrasonic detection, pre-drilled in-situ rock shear measurements, in-situ tests of borehole shear elastic modulus, and drill body torque methods, but they are quite time-consuming and the test data is single.

[0004] In the actual application process, it is found that the current drilling shearing equipment has the following main problems: 1: The effective shearing area of ​​the rock in the drilling shear tester is small, less than 5 square centimeters; in addition, since the height of the shear teeth on the shear plate is only 1mm, the shear thickness is very small. If the borehole wall is incomplete, the test results will be smaller. 2: Due to the presence of the shear teeth on the shear plate, the rock mass of the borehole wall has been damaged during the process of the shear teeth being embedded in the borehole rock wall, and the teeth on the shear plate will also shear the rock mass on it during the test. Therefore, it will also have a certain impact on the test results. 3: In order to understand the deformation characteristics of the rock mass, drilling elastic modulus tests are often carried out simultaneously in engineering applications, and different drilling test equipment are carried out alternately. Therefore, the test implementation is cumbersome, and the test data obtained are not conducive to comparative analysis.

[0005] A Chinese invention patent with publication number CN118190665A discloses a portable in-situ in-hole direct shear mechanical testing device and test method for soil, which include a main mechanical structure, a data acquisition and control structure, and a hydraulic system. The main mechanical structure includes a fixed column, a rod interface is provided at the top of the fixed column, a hydraulic oil pipe hole A and a hydraulic oil pipe hole B are respectively provided at the top of the fixed column, three pushing components are provided on the outside of the fixed column, the pushing components include three pushing plates slidably clamped on the outside of the fixed column, the inner sides of the pushing plates are connected to the hydraulic system through the normal force oil pipe A connected in the hydraulic oil pipe hole A, the three pushing plates are all arranged in the same vertical plane, any two of the pushing plates are arranged on the same horizontal straight line, a pusher is provided on the opposite side of the other pushing plate, and the pusher is connected to the hydraulic system through a pipeline connected in the normal force oil pipe B.

[0006] In actual use, this solution requires that the jacking device be pushed into the hole wall to be fixed by means of jacking, and then a tangential force is applied to lift the connecting rod to obtain experimental data by causing rock and soil damage. In the process of pushing the jacking device into the hole wall, the density and structure of the rock and soil in the test area are damaged, and the data obtained thereby also has the problem of inaccurate measurement. Summary of the invention

[0007] In view of the deficiencies in the above-mentioned background technology, the present invention proposes a system and method for in-situ precise testing of rock mass strength, which solves the problem in the prior art that the shear strength of rock mass cannot be accurately measured in-situ.

[0008] The technical solution of the present invention is achieved as follows: a precise in-situ rock strength testing system, comprising a drilling ring cutting device for opening a double-position annular groove in a borehole on the rock mass, and an in-situ strength testing system for being arranged at the double-position annular groove; the drilling ring cutting device comprises a drill body, in which an annular cutter and an adjustment mechanism are arranged, the adjustment mechanism cooperates with the annular cutter and can control the annular cutter to extend perpendicular to the drill body or be retracted into the drill body; the in-situ strength testing system comprises a supply assembly, the supply assembly is connected to a two-way airbag assembly, and the two-way airbag assembly is arranged on a support frame; a test rock mass is formed on the rock mass between the double-position annular grooves, and the support frame is used to place the two-way airbag assembly into the double-position annular groove to cooperate with the test rock mass.

[0009] Preferably, the bidirectional airbag assembly includes a radial airbag and an axial airbag sequentially arranged along the axial direction, the radial airbag and the axial airbag are both annular airbags, and the support frame is connected to the inner side of the radial airbag and the axial airbag respectively.

[0010] Preferably, the radial airbag and the axial airbag are respectively connected to the intelligent opening and closing valve through high-pressure resistant pipes, and the intelligent opening and closing valve is connected to the supply component.

[0011] Preferably, the supply assembly includes a pressure pump, which is connected to the intelligent on-off valve and can pump the medium into the axial airbag and the radial airbag through the intelligent on-off valve and the high-pressure resistant pipeline. The outlet end of the intelligent on-off valve is connected to a pressure gauge.

[0012] Preferably, the annular cutter includes rectangular cutter heads arranged in pairs, and the drill body is provided with pairs of sliding holes perpendicular to the axis of the drill body, and the rectangular cutter heads are slidably matched with the sliding holes respectively; the adjustment mechanism includes a center rod coaxially slidably arranged inside the drill body, a push seat is provided at the front end of the center rod, a push block for matching with the rectangular cutter head is provided on the push seat, a slope is provided between the push block and the rectangular cutter head, a guide bevel is provided on the push seat, a guide column is provided on the side wall of the rectangular cutter head and slidably matches with the guide bevel through the guide column, and a reset spring is provided between the front end of the push seat and the end of the drill body.

[0013] Preferably, the tail of the center rod is connected to a piston plate, which is provided with a water hole. The piston plate slides with the inner wall of the drill body, a drainage hole is provided at the front end of the drill body, and a water gap is provided between the sliding hole and the rectangular cutter head.

[0014] Preferably, the double-position annular groove comprises two annular grooves coaxially opened in sequence along the length direction of the borehole, the cross-sections of the two annular grooves are both rectangular rings, and the rock mass between the two annular grooves forms a test rock mass.

[0015] A method for in-situ precise testing of rock mass strength, using the in-situ precise testing system for rock mass strength as described above, comprises the following steps: Step 1: Drill a hole in the rock mass and use a drilling circumferential cutting device to perform multiple hole expansion processes to form multiple sets of double-position circumferential cutting grooves in the hole, and then withdraw the drill and clean the slag.

[0016] Step 2: Use the support frame to place the bidirectional airbag assembly in place and make it correspond to one set of the two-position annular grooves.

[0017] Step three: Use the supply assembly to supply pressure to the bidirectional airbag assembly for pre-expansion, and achieve positioning and alignment of the bidirectional airbag assembly with the double-position annular groove.

[0018] Step 4: Use the supply assembly to supply pressure to the bidirectional airbag assembly so that the bidirectional airbag assembly applies pressure to the test rock mass, fix the pressure of the radial airbag, gradually increase the pressure of the axial airbag until the test rock mass is sheared, and record the pressure parameters.

[0019] Step 5: Repeat steps 2 to 4 above. In step 4, change the pressure of the radial airbag and gradually increase the pressure of the axial airbag until the test rock mass is sheared. Perform pressure tests on other groups of double-position annular grooves and collect data. Calculate the internal friction angle and cohesion parameters of the original rock through the multiple sets of data obtained to complete the precise test of the original rock strength.

[0020] Preferably, the spacing between the multiple groups of double-position annular grooves opened in the step one is greater than the thickness of the test rock mass; when the pressure test is performed in the step four, when the two-way airbag assembly cuts off the test rock mass under pressure, the pressure parameters are recorded to complete a single shear test; when the pressure test of multiple groups of double-position annular grooves is performed in the step five, the air pressure of the two-way airbag assembly is gradually changed to perform a comparative test.

[0021] The beneficial effects of the present invention are as follows: the present invention uses a drilling ring cutting device to open a plurality of groups of double-position annular grooves in a pre-drilled hole on a rock mass, thereby forming an isolated test rock mass along the axial direction in the drill hole of the rock mass, and utilizing the double-position annular grooves to provide space for the placement of a two-way airbag assembly, so that the two-way airbag assembly can cooperate with the test rock mass, and the formed test rock mass has no rock mass connection on both sides along the axial direction. Therefore, the medium is supplied to the two-way airbag assembly through the supply assembly, so that during the expansion process of the two-way airbag assembly, pressure in the axial direction and the normal direction can be applied to the test rock mass at the same time, thereby achieving the purpose of shear testing the test rock mass, and finally, according to the recorded medium pressure during the shear process, the corresponding rock mass strength shear data is obtained.

[0022] The test rock mass specifications formed by this system are standard, with fewer error inducements, so the measurement results are more accurate and more reliable. Using the method of this system, in-situ measurement can be achieved, the operation steps are simple, and the data determination is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0024] Figure 1 This is a schematic diagram of the shear test state of the present invention; Figure 2 This is a schematic diagram of the external structure of the drilling ring cutting device of the present invention; Figure 3 It is a schematic diagram of the cross-sectional structure of the drilling ring cutting device of the present invention; Figure 4 It is a schematic diagram of the regulating mechanism of the present invention; Figure 5 It is a schematic diagram of the cross-sectional structure of the adjustment mechanism of the present invention; In the figure: 1: drill body, 2: annular cutter, 3: adjustment mechanism, 4: test rock mass, 5: supply assembly, 6: two-way airbag assembly, 7: support frame, 8: radial airbag, 9: axial airbag, 10: high-pressure pipe, 11: intelligent opening and closing valve, 12: pressure pump, 13: pressure gauge, 14: rectangular cutter head, 15: sliding hole, 16: center rod, 17: push seat, 18: push block, 19: first return spring, 20: return spring, 21: piston plate, 22: water hole, 23: drainage hole, 24: annular groove. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] like Figure 1 As shown, Example 1 is an in-situ precise testing system for rock mass strength, including a drilling ring cutting device for opening a double-position annular groove in a borehole on the rock mass, and an in-situ strength testing system for being arranged at the double-position annular groove. Among them, the double-position annular groove includes two annular grooves 24 coaxially opened in sequence along the length direction of the borehole, and the cross-sections of the two annular grooves 24 are both rectangular rings. The rock mass between the two annular grooves 24 forms a test rock mass 4. The thickness and size of the test rock mass formed by the ring cutting of the drilling ring cutting device are standard in the axial direction, and there is no redundant rock mass connection on both sides of the test rock mass in the axial direction. Therefore, the test data obtained in the subsequent shearing process of the test rock mass in the axial direction is more accurate.

[0027] Specifically, Figure 2 , 3 As shown, the drilling ring cutting device includes a drill body 1, in which an annular cutter 2 and an adjustment mechanism 3 are arranged. The adjustment mechanism 3 cooperates with the annular cutter 2, and the adjustment mechanism 3 can control the annular cutter 2 to extend perpendicularly to the drill body 1 or be retracted into the drill body 1. After selecting the in-situ test position, a conventional drill bit is used to drill a hole in the corresponding rock mass in advance, and then the drill body is connected to the drilling rig and placed in the pre-drilled borehole. After moving into the borehole, the annular cutter is extended out of the drill body through the adjustment mechanism to expand the borehole. The annular cutter cuts and expands the inner wall of the borehole while expanding, thereby forming a double-position annular cutting groove in the borehole.

[0028] Specifically, the in-situ strength testing system includes a supply assembly 5, which is connected to a bidirectional airbag assembly 6. The bidirectional airbag assembly 6 is arranged on a support frame 7. A test rock mass 4 is formed on the rock mass between the double-position annular grooves. The support frame 7 is used to place the bidirectional airbag assembly 6 into the double-position annular groove to cooperate with the test rock mass 4.

[0029] During the use of this system, multiple sets of double-position annular grooves are opened in the pre-drilled boreholes on the rock mass through the drilling ring cutting device, so as to form an isolated test rock mass 4 in the axial direction of the borehole, and the double-position annular grooves are used to provide space for the placement of the two-way airbag assembly 6, so that the two-way airbag assembly 6 can cooperate with the test rock mass 4, and the test rock mass 4 formed has no rock mass connection on both sides along the axial direction. Therefore, when the medium is supplied to the two-way airbag assembly 6 through the supply assembly 5, the two-way airbag assembly 6 is expanded, and pressure can be applied to the test rock mass 4 in the axial direction and the normal direction at the same time, thereby achieving the purpose of shear testing the test rock mass 4. Finally, the corresponding rock strength shear data is obtained according to the recorded medium pressure during the shearing process. The test rock mass 4 formed by this system has standard specifications and few error inducements, so the measurement results are more accurate and more reliable.

[0030] Embodiment 2, on the basis of embodiment 1, the bidirectional airbag assembly 6 includes a radial airbag 8 and an axial airbag 9 arranged in sequence along the axial direction, the radial airbag 8 and the axial airbag 9 are both annular airbags, and the support frame 7 is respectively connected to the inner side of the radial airbag 8 and the axial airbag 9. In the process of sending the bidirectional airbag assembly 6 into the borehole through the support frame 7 and cooperating with the double-position annular groove and the test rock mass 4, the radial airbag 8 is sent to the position corresponding to the inner hole surface of the test rock mass 4, so that in the subsequent process of the radial airbag 8 pumping the medium to expand, the expansion force generated is applied to the inner hole surface of the test rock mass 4 in the radial direction, thereby forming a normal pressure applied to the test rock mass 4 during the shear test. The axial airbag 9 is sent into any one of the annular grooves 24 of the double-position annular grooves. When restricted by the annular grooves 24 and expanded by the medium pumped in, the axial airbag 9 continuously applies pressure to the test rock mass 4 in the axial direction, thereby forming a shear force on the test rock mass 4 until the test rock mass 4 is cut off and separated from the rock mass connected to the outside, and the corresponding rock mass strength data can be obtained.

[0031] Correspondingly, the radial airbag 8 and the axial airbag 9 are respectively connected to the intelligent opening and closing valve 11 through the high-pressure resistant pipe 10, and the intelligent opening and closing valve 11 is connected to the supply component 5. Among them, the supply component 5 includes a pressure pump 12, and the pressure pump 12 is connected to the intelligent opening and closing valve 11. When the pressure pump 12 is powered on, it can pump the medium into the axial airbag 8 and the radial airbag 9 through the intelligent opening and closing valve 11 and the high-pressure resistant pipe 10. In this embodiment, the pumped medium can be selected as a gas medium or a liquid medium, and the pumping of the medium is used to cause the radial airbag 8 and the axial airbag 9 to tend to expand.

[0032] In addition, in this embodiment, the outlet end of the intelligent on-off valve 11 is connected with a pressure gauge 13, so that the pressure gauge 13 is used to measure the medium pressure of the corresponding axial airbag 8 and radial airbag 9. As a further optional solution, after the medium pressure obtained by the radial airbag 8 reaches the set value, the intelligent on-off valve 11 of the corresponding high-pressure resistant pipeline 10 is closed to maintain a constant pressure, thereby maintaining a constant normal force.

[0033] Embodiment 3, on the basis of embodiment 2, as Figure 4 , 5 As shown, the annular cutter 2 includes rectangular cutter heads 14 arranged in pairs, and the drill body 1 is provided with pairs of sliding holes 15 perpendicular to the axis of the drill body 1, and the rectangular cutter heads 14 are respectively slidably matched with the sliding holes 15. In this embodiment, a total of four rectangular cutter heads 14 are provided, and four sliding holes 15 are correspondingly provided, which are arranged in pairs and symmetrically on both sides of the drill body 1. The sliding holes 15 are sliding holes with rectangular cross-sections, so as to better match with the rectangular cutter heads 14. The axial distance between adjacent rectangular cutter heads along the axial direction is equal to the thickness of the formed test rock mass 4.

[0034] In addition, the adjustment mechanism 3 includes a center rod 16 coaxially slidably arranged inside the drill body 1, a push seat 17 is provided at the front end of the center rod 16, a push block 18 for cooperating with the rectangular cutter head 14 is provided on the push seat 17, a slope is provided between the push block 18 and the rectangular cutter head 14, a guide inclined groove 19 is provided on the push seat 17, a guide column is provided on the side wall of the rectangular cutter head 14 and the guide column is slidably matched with the guide inclined groove 19, and a reset spring 20 is provided between the front end of the push seat 17 and the end of the drill body 1. In this embodiment, both sides of the push block 18 are provided with a slope, and the slope angle is the same as the guide inclined groove angle. When the center rod 16 pushes the push block 18 to move toward the front end of the drill body 1, the slope on the push block 18 contacts the slope at the rear end of the rectangular cutter head 14, thereby pushing the rectangular cutter head 14 out of the drill body in a direction perpendicular to the axis of the drill body 1. At this time, the guide column on the rectangular cutter head slides along the guide inclined groove, and at the same time, the push block moves forward to compress the reset spring. When the push block loses the power to push forward, the reset spring expands, pushing the push block and the center rod back to reset. At the same time, the rectangular cutter head moves in the guide bevel groove and retreats into the drill body in cooperation with the guide column and the guide bevel groove.

[0035] As a further optional embodiment, the rear end of the center rod 16 is connected to a piston plate 21, and a water hole 22 is provided on the piston plate 21. The piston plate 21 is slidably matched with the inner wall of the drill body 1, and a drainage hole 23 is provided at the front end of the drill body 1. In actual use, the rear end of the drill body 1 is connected to the drilling rig, and the rear end of the drill body is connected to a conventional water supply end through a rotary joint. During the hole expansion process, the water supply end supplies high-pressure water into the drill body, and the high-pressure water pushes the piston plate to move axially, thereby synchronously pushing the push block 18 to move through the center rod to achieve the external expansion of the rectangular cutter head. At the same time, the drilling rig drives the drill body to rotate, and the extended rectangular cutter head is used to complete the excavation of the double-position annular groove. In this process, part of the supplied high-pressure water enters the drill body through the water hole, and is discharged into the drill hole through the drainage hole, so that the drill cuttings scraped off by the rectangular cutter head are discharged from the drill hole, and a certain pressure relief purpose is achieved at the same time.

[0036] As a further optional embodiment, a water gap is provided between the sliding hole 15 and the rectangular cutter head 14, so that after high-pressure water enters the drill body, part of it is discharged through the water gap, which is beneficial to the discharge of drilling cuttings to the outside of the borehole.

[0037] Embodiment 4, a method for in-situ precise testing of rock mass strength, using the in-situ precise testing system for rock mass strength as described in any of the above embodiments, comprises the following steps: Step 1: Use an anchor drill to drill a hole in the rock mass, and use a drilling ring cutting device to perform multiple hole expansion processes to form multiple sets of double-position annular grooves in the hole, and then withdraw the drill and clean the slag. Among them, the rock mass spacing between the multiple sets of double-position annular grooves formed by the hole expansion process is greater than the thickness of the test rock mass 4, so as to avoid the phenomenon that the test rock mass cannot be cut off during the shear test.

[0038] Step 2: Use the support frame 7 to place the bidirectional airbag assembly 6 in place and make it correspond to one set of the two-position annular grooves.

[0039] Step 3: Use the supply assembly 5 to supply pressure to the bidirectional airbag assembly 6 for pre-expansion, and align the radial airbag 8 of the bidirectional airbag assembly 6 with the inner annular surface of the test rock mass 4, and align the axial airbag 9 with an annular groove 24 of the double-position annular groove. At the same time, the sensitivity and accuracy of the intelligent on-off valve pressure gauge are tested.

[0040] Step 4: Set the supply pressure of the radial airbag and the axial airbag, use the supply component 5 to supply pressure to the bidirectional airbag component 6 so that the bidirectional airbag component 6 applies pressure to the test rock mass 4, fix the pressure of the radial airbag, and gradually increase the pressure of the axial airbag until the test rock mass is sheared, collect and record the pressure parameters of the radial airbag and the axial airbag at this time, and complete a single shear test.

[0041] Step 5: Repeat the above steps 2 to 4 to perform shear tests on the test rock mass between the two-position annular grooves of other groups. During the operation of step 4, the pressure of the radial airbag is changed successively in different groups, and the pressure of the axial airbag is gradually increased until the test rock mass is sheared, and data is collected to achieve the measurement of the tangential pressure under the control of gradually changing the applied normal pressure. The internal friction angle and cohesion parameters of the original rock are calculated by analyzing the obtained multiple sets of data, and the precise test of the original rock strength parameters is completed. Through comparative tests, interference and errors are reduced, and more accurate experimental data are obtained.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A rock mass strength in-situ precision testing system, characterized by: It includes a drilling ring cutting device for opening a double-position annular groove in a borehole on a rock mass, and an in-situ strength testing system for being arranged at the double-position annular groove; The drilling ring cutting device comprises a drill body (1), wherein an annular cutter (2) and an adjustment mechanism (3) are arranged in the drill body (1), and the adjustment mechanism (3) cooperates with the annular cutter (2) and can control the annular cutter (2) to extend perpendicularly to the drill body (1) or to be retracted into the drill body (1); The in-situ strength test system comprises a supply assembly (5), the supply assembly (5) being connected to a bidirectional airbag assembly (6), the bidirectional airbag assembly (6) being arranged on a support frame (7); a test rock mass (4) is formed on the rock mass between the double-position annular grooves, the support frame (7) being used to place the bidirectional airbag assembly (6) into the double-position annular groove and to match the test rock mass (4).

2. The rock mass strength in-situ precision testing system according to claim 1 is characterized by: The bidirectional airbag assembly (6) comprises a radial airbag (8) and an axial airbag (9) which are arranged in sequence along the axial direction, the radial airbag (8) and the axial airbag (9) are both annular airbags, and the support frame (7) is connected to the inner side of the radial airbag (8) and the inner side of the axial airbag (9), respectively.

3. The rock mass strength in-situ precision testing system according to claim 2 is characterized by: The radial airbag (8) and the axial airbag (9) are respectively connected to the intelligent on-off valve (11) via a high-pressure resistant tube (10), and the intelligent on-off valve (11) is connected to the supply component (5).

4. The rock mass strength in-situ precise testing system according to claim 3 is characterized by: The supply assembly (5) comprises a pressure pump (12), the pressure pump (12) being connected to the intelligent on-off valve (11), and the pressure pump (12) being capable of pumping a medium into the axial airbag (8) and the radial airbag (9) via the intelligent on-off valve (11) and the high-pressure resistant pipe (10).

5. The rock mass strength in-situ precise testing system according to claim 4 is characterized by: The outlet end of each intelligent on-off valve (11) is connected to a pressure gauge (13).

6. The rock mass strength in-situ precision testing system according to any one of claims 1 to 5, characterized in that: The annular cutter (2) comprises a pair of rectangular cutter heads (14), a pair of sliding holes (15) perpendicular to the axis of the drill body (1) are opened on the drill body (1), and the rectangular cutter heads (14) are respectively slidably matched with the sliding holes (15); the adjustment mechanism (3) comprises a center rod (16) coaxially slidably arranged inside the drill body (1), a push seat (17) is provided at the front end of the center rod (16), a push block (18) for matching with the rectangular cutter head (14) is provided on the push seat (17), a slope is provided between the push block (18) and the rectangular cutter head (14), a guide inclined groove (19) is provided on the push seat (17), a guide column is provided on the side wall of the rectangular cutter head (14) and the guide column is slidably matched with the guide inclined groove (19), and a return spring (20) is provided between the front end of the push seat (17) and the end of the drill body (1).

7. The rock mass strength in-situ precise testing system according to claim 6, characterized in that: The rear end of the center rod (16) is connected to a piston plate (21), a water hole (22) is provided on the piston plate (21), the piston plate (21) is slidably matched with the inner wall of the drill body (1), a drainage hole (23) is provided at the front end of the drill body (1), and a water gap is provided between the sliding hole (15) and the rectangular cutter head (14).

8. The rock mass strength in-situ precision testing system according to claim 7 is characterized by: The double-position annular groove comprises two annular grooves (24) coaxially opened in sequence along the length direction of the borehole, the cross-sections of the two annular grooves (24) are both rectangular rings, and the rock mass between the two annular grooves (24) forms a test rock mass (4).

9. A method for in-situ precise testing of rock mass strength, using the in-situ precise testing system for rock mass strength as claimed in any one of claims 1 to 8, characterized in that: The steps include: Step 1: Drill a hole in the rock mass, and use a drilling ring cutting device to perform multiple hole expansion processes to form multiple sets of double-position annular grooves in the hole, and then withdraw the drill and clean the slag; Step 2: using the support frame (7) to place the bidirectional airbag assembly (6) in place and make it correspond to one of the sets of bidirectional annular grooves; Step 3: using the supply component (5) to supply pressure to the bidirectional airbag component (6) for pre-expansion, and achieving positioning and alignment between the bidirectional airbag component (6) and the double-position annular groove; Step 4: using the supply assembly (5) to supply pressure to the bidirectional airbag assembly (6) so that the bidirectional airbag assembly (6) applies pressure to the test rock mass (4), performing a pressure test, and recording pressure parameters; Step 5: Repeat steps 2 to 4 above, perform pressure tests on other groups of double-position circumferential grooves, and collect data. Calculate the original rock internal friction angle and cohesion parameters through the multiple sets of data obtained to complete the precise test of the original rock strength.

10. The in-situ precise rock mass strength testing method according to claim 9, characterized in that: The spacing between the multiple sets of double-position annular grooves opened in step one is greater than the thickness of the test rock mass (4); when the pressure test is performed in step four, when the two-way airbag assembly (6) cuts off the test rock mass (4) under pressure, the pressure parameters at this time are recorded to complete a single shear test; when the pressure test of the multiple sets of double-position annular grooves is performed in step five, the air pressure of the two-way airbag assembly (6) is gradually changed to perform a comparative test.

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