A rock mass lateral load plate test system and method

Abstract

The invention discloses a rock mass lateral load flat plate test system and method. The system comprises a loading module for applying load to a rock specimen, a detection module for detection, a fixing module for fixing, and a data module for storing parameters; the fixing module comprises a loading frame, the loading module comprises a bearing steel pad, a loading steel pad, a guide rod and a jack, the bearing steel pad is fixed on the loading frame, the guide rod is slidably connected with the loading frame, the loading steel pad is fixed to the end of the guide rod, and is arranged in parallel with the bearing steel pad, and the two are located on the inner side of the loading frame, and the two ends of the jack are respectively fixed on the loading frame and the loading steel pad, and the loading steel pad can be pushed to apply load to the rock specimen; the detection module comprises a pressure gauge and a displacement sensor, the pressure gauge is respectively arranged on the bearing steel pad and the loading steel pad, and the displacement sensor is arranged on the rock specimen, so as to solve the problem that a reaction force device needs to be arranged in a flat plate load test device and the deformation of the loading frame is easy to affect the test accuracy.

Description

Technical Field

[0001] The invention relates to the field of geotechnical engineering in-situ test, and more specifically, to a rock mass lateral load flat plate test system and method. Background Art

[0002] The plate load test is the earliest and most widely used in-situ test method. The test is to apply loads in stages on a rigid pressure plate of a certain size, observe the pressure and deformation of the natural foundation under each level of load, and determine the bearing capacity and deformation modulus of the foundation soil according to the load-settlement relationship curve. In actual operation, the plate load test is often time-consuming, labor-intensive and costly. This is mainly because the load applied to the plate is generally provided by a reaction device. The ease of use of the reaction device directly affects the process, results and cost of the test. Commonly used devices include piled reaction beam devices and anchor pile reaction beam devices. For the plate load test on the rock foundation, a larger and more stable reaction force needs to be provided, and the reaction device has higher requirements. At the same time, it also brings about an exponential increase in the test cost. The test cost of one point can reach tens of thousands of yuan. In addition, for the piled reaction beam device, it is not uncommon for the piled reaction beam device to become unstable due to excessive or uneven distribution of the piled load during the test, resulting in loss of life and property.

[0003] The existing technology has the following disadvantages: (1) a special reaction force device is required to balance the forces during loading; (2) only a flat plate load test can be performed, and the function of recording displacement and pressure for relaxation test cannot be realized. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a rock lateral load flat plate test system and method. The test system realizes self-balancing of the action force and reaction force during loading through a square loading frame, and does not need to set up a reaction force device, which greatly reduces the cost of on-site rock flat plate load testing and simplifies the test operation. A displacement sensor is arranged between the loading steel pad and the bearing steel pad to directly obtain the rock deformation data during loading, thereby improving the accuracy and reliability of the test results, and solving the problem that the flat plate load test device needs to be set up with a reaction force device and the deformation of the loading frame easily affects the test accuracy.

[0005] In order to achieve the above object, according to one aspect of the present invention, a rock mass lateral load plate test system is provided, comprising:

[0006] A loading module for applying load to the rock specimen, a detection module for detecting pressure and displacement parameters, a fixing module for fixing the loading module and the detection module, and a data module for storing pressure and displacement parameters;

[0007] The fixing module comprises a loading frame, the loading module comprises a bearing steel pad, a loading steel pad plate, a guide rod and a jack, the bearing steel pad plate is fixed on the loading frame, the guide rod is slidably connected to the loading frame, the loading steel pad plate is fixed to the end of the guide rod, and is arranged parallel to the bearing steel pad plate, both of which are located on the inner side of the loading frame, and the two ends of the jack are respectively fixed to the loading frame and the loading steel pad plate, and are used to push the loading steel pad plate to apply load to the rock specimen;

[0008] The detection module includes a pressure gauge and a displacement sensor. The pressure gauge is respectively arranged on the bearing steel pad and the loading steel pad, and the displacement sensor is arranged on the rock specimen. The pressure gauge and the displacement sensor are respectively connected to the data module signal.

[0009] Furthermore, the loading frame includes a load-bearing beam located at the upper portion, the loading module includes a fixed bracket, the fixed bracket is fixed on the load-bearing beam, and the load-bearing steel pad is fixed on the fixed bracket.

[0010] Furthermore, the loading frame includes a level bubble, and the level bubble is fixed on the loading frame and is used to level the fixing module.

[0011] Furthermore, the loading frame includes a loading beam, the loading beam is arranged at the bottom of the loading frame, the jack is fixed on the loading beam, and the guide is slidably connected to the loading beam.

[0012] Furthermore, the loading module includes a guide sleeve, a seat tube clamp and a jack mounting seat, the guide sleeve is fixed on the loading beam, the guide sleeve corresponds to the position and quantity of the guide rod, the two are slidably connected, the seat tube clamp is bolted to the guide rod for fixing the guide rod, and the jack mounting seat is fixed to the loading steel plate for fixing the jack.

[0013] Furthermore, it includes a threaded bottom hole and a pressure head, the threaded bottom hole is arranged on the bearing steel pad and the loading steel pad, and is used to screw and fix the pressure head, the pressure head is fixed toward one side of the rock specimen, and is used to apply pressure to the rock specimen, and the pressure gauge is fixed on the pressure head.

[0014] According to another aspect of the present invention, there is provided a rock mass lateral load plate test method, comprising the following steps:

[0015] S100, adjusting the pressure testing machine to a minimum load, which is 5KN or 2% of the maximum load. The minimum value of the two is selected during the actual test. After the adjustment is completed, the pressure testing machine is left to stand until the vertical load force of the pressure testing machine is stable.

[0016] S200, fix the rock specimen, put a square loading frame on the outside of the rock specimen, then fix the rock specimen, and level and fix the square loading frame;

[0017] S300, connect the sensor and adjust it to be stable, connect the sensor to the intelligent static strain gauge distribution box, observe the initial stable reading of the sensor, read each gauge once at a fixed interval, and take the reading as the initial reading value of each gauge after three consecutive readings remain unchanged;

[0018] S400, start the loading test, apply load to the rock specimen step by step, and apply load in 10 levels. The first level is 1 / 5 of the estimated design load, and each subsequent level is 1 / 10 of the estimated design load. Single-cycle loading is adopted. Within the first hour of each level of load, the pressure on the rock specimen and the displacement generated are recorded and measured at intervals of 5min, 10min, 15min, 15min, and 15min. Thereafter, the records are recorded every 30min. During each load increase, the load is uniformly loaded until the specimen is destroyed. The load number displayed by the intelligent static strain gauge is recorded, and the phenomena during the pressurization process and the appearance description of the specimen after destruction are recorded in the record table;

[0019] S500, terminate loading. When the following phenomena occur, the rock specimen has reached failure and loading can be terminated. The phenomena include obvious lateral extrusion, bulging or cracking of the soil around the loading steel pad or the bearing steel pad; under a certain level of load, the displacement rate cannot reach the stability standard within 24 hours; the total load has reached more than twice the design requirement value.

[0020] Further, including:

[0021] S600, observe the rebound value of the rock specimen, unload the load on the rock specimen, and the unloading amount at each level is twice the amount added when the load is increased. The pressure on the rock specimen and the displacement generated are recorded and measured every 10 minutes. Each level of load lasts for 1 hour. After all the loads are unloaded, observe for 3 hours. The observation time intervals are 10 minutes, 20 minutes, 30 minutes, 1 hour and 1 hour;

[0022] Further, including:

[0023] S101, collecting rock samples. This step is performed before S100. After determining the plane position and depth of the required test point, a vertical test hole is excavated around the test point by artificial digging, and a concrete retaining wall is poured around the pit according to the design requirements. After the concrete retaining wall reaches the design strength, the pit is continued to be excavated around the test point according to the design requirements, and the rock mass at the test point is excavated into a rock specimen. The disturbed rock mass on the working surface of the rock specimen is cleaned, and the working surface of the rock specimen is repaired and leveled. A water collection pit is set around the rock specimen, and a support ring is built around the periphery with bricks;

[0024] S102, trim and record rock specimen information. This step is performed after S101 and before S100. Verify the name of the rock specimen, describe the specimen color, particles, bedding, joints and fissures, and weathering degree, and write them in the record sheet. Use an electronic vernier caliper to measure the distance between the loading points of the rock specimen and record it in the table. For irregular specimens that are difficult to place stably under the pressure head, use tools such as a geological hammer to trim them.

[0025] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0026] 1. The present invention provides a rock lateral load flat plate test system, which realizes self-balancing of action force and reaction force during loading through a square loading frame, and does not need to set up a reaction force device, thereby greatly reducing the cost of on-site rock flat plate load test and simplifying the test operation. A displacement sensor is arranged between the loading steel pad and the bearing steel pad to directly obtain rock deformation data during loading, thereby improving the accuracy and reliability of test results, and solving the problem that a reaction force device needs to be set up in a flat plate load test device and that deformation of the loading frame easily affects the test accuracy.

[0027] 2. The present invention provides a rock lateral load plate test method, which connects the sensor to an intelligent static strain gauge distribution box. Before the test begins, the initial stable reading of the sensor is observed, and each meter is read once at regular intervals. After the reading is stable, the pressure test is started again, and this reading is used as the initial reading value of each meter, thereby ensuring the accuracy of subsequent loading test data.

[0028] 3. The present invention provides a rock lateral load flat plate test method. After the flat plate load test record is completed, the rock specimen is unloaded step by step, and the pressure and displacement of the rock specimen are recorded. After all the loads are unloaded, the observation is continued, and the stress relaxation test is completed in the same test operation, thereby improving the test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a front view of a rock mass lateral load flat plate test system according to an embodiment of the present invention;

[0030] Figure 2 is a cross-sectional view AA of a rock mass lateral load flat plate test system according to an embodiment of the present invention;

[0031] Figure 3 BB is a cross-sectional view of a rock mass lateral load flat plate test system according to an embodiment of the present invention;

[0032] Figure 4 is a cross-sectional view CC of a rock mass lateral load flat plate test system according to an embodiment of the present invention;

[0033] Figure 5 The present invention is a test flow chart of a rock mass lateral load plate test system according to an embodiment of the present invention.

[0034] In all the drawings, the same figure marks represent the same technical features, specifically: 1-square loading frame, 2-load-bearing beam, 3-fixed bracket, 4-load-bearing steel pad, 5-loading steel pad, 6-horizontal bubble, 7-guide rod, 8-jack mounting seat, 9-jack, 10-guide sleeve, 11-loading beam, 12-angle bracket, 13-pressure gauge, 14-displacement sensor, 15-seat tube clamp, 16-threaded bottom hole, 17-pressure head. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] like Figure 1-Figure 5As shown, the present invention provides a rock lateral load flat plate test system, including a fixing module, a loading module, a detection module and a data module, wherein the fixing module includes a square loading frame 1, the loading frame includes a load-bearing beam 2 located at the upper frame, a loading beam 11 located at the lower frame, and a level bubble 6 fixed on the left frame and the right frame. Preferably, the level bubble 6 is arranged in the middle of the left frame and the right frame to adjust the horizontality of the system. An angle bracket 12 is arranged at the connection between the upper and lower frames and the two side frames to enhance stability. Further, the loading module includes a fixing bracket 3, a load-bearing steel pad 4, a loading steel pad 5, a guide rod 7 and a jack 9, wherein the fixing bracket 3 is arranged and fixedly installed on the load-bearing beam 2, and the end of the fixing bracket 3 faces the square loading frame 1, on which the load-bearing steel pad 4 is fixed, and the loading steel pad 5 is fixed at the end of the guide rod 7, and the guide rod 7 is slidably connected to the loading beam 11. Preferably , more than two guide rods 7 are arranged, and the loading steel pad 5 and the bearing steel pad 4 correspond to each other and are parallel to each other. One end of the jack 9 is fixed on the loading beam 11, and the other end is fixed to the bottom of the loading steel pad 5 through the jack mounting seat 8. The jack 9 is arranged along the center line of the square loading frame 1, the bearing steel pad 4 and the loading steel pad 5. The square rock sample is arranged between the bearing steel pad 4 and the loading steel pad 5. Further, the detection module includes a pressure gauge 13 and a displacement sensor 14. Preferably, the displacement sensor 14 can adopt an LVDT displacement sensor. The pressure gauge 13 is respectively arranged on the side of the bearing steel pad 4 and the loading steel pad 5 facing the rock specimen, which is used to collect pressure size data. The displacement sensor 14 is arranged between the loading steel pad 5 and the bearing steel pad 4 for relative displacement measurement, which solves the problem that the flat plate load test device needs to be provided with a reaction force device and the deformation of the loading frame easily affects the test accuracy.

[0037] Furthermore, if Figure 1-Figure 5 As shown, in the present test system, the loading module further includes a guide sleeve 10 and a seat tube clamp 15, wherein the guide sleeve 10 and the guide rod 7 are provided with the same number and position, the guide sleeve 10 penetrates and is fixed on the load-bearing beam 2 of the lower frame, the guide sleeve 10 is slidably connected with the guide rod 7, when the jack 9 pushes the loading steel pad 5 to displace, the guide sleeve 10 prevents the guide rod 7 from directional deviation, the seat tube clamp 15 is bolted to clamp the guide rod 7, and is used to fix the guide rod 7 to prevent sliding during the test preparation process, further, the pressure gauge 13 is used to collect the pressure between the rock sample and the load-bearing steel pad 4 and the loading steel pad 5, the displacement sensor 14 is used to collect the relative displacement change between the two, and transmit the data to the data module for processing and storage, and the data module can be a computer or a control platform.

[0038] Furthermore, if Figure 1-Figure 5As shown, in the test system, the measuring module also includes a threaded bottom hole 16 and a pressure head 17. The threaded bottom hole 16 is arranged on the side of the bearing steel pad 4 and the loading steel pad 5 facing the rock specimen. The pressure head 17 is screwed on the threaded bottom hole 16. Preferably, the pressure head 17 adopts a truncated cone structure. After being fixed on the bearing steel pad 4 and the loading steel pad 5 respectively, the pressure head 17 is in direct contact with the rock specimen and squeezes the rock specimen during the loading process. The pressure gauge 13 is fixedly mounted on the pressure head 17.

[0039] like Figure 1-Figure 5 As shown, according to another aspect of the present invention, the present invention provides a rock mass lateral load plate test method, which specifically includes:

[0040] S100, regulating pressure testing machine;

[0041] Specifically, adjust the pressure testing machine to the minimum load, which can be 5KN or 2% of the maximum load. The minimum value of the two should be selected during the actual test. After the adjustment is completed, let it stand for a period of time to stabilize the vertical load force of the pressure testing machine.

[0042] S200, fixed rock specimen;

[0043] Specifically, a square loading frame is put on the outside of the rock specimen, and the pressure heads are screwed into the threaded bottom holes on the loading steel pad and the bearing steel pad, respectively. The square loading frame is leveled and fixed by adjusting the positions of the angle bracket and the square loading frame, and at the same time, the bearing steel pad and the loading steel pad are parallel to the working surfaces on the opposite sides of the rock specimen, so that the rock specimen is between the pressure heads on the loading steel pad and the bearing steel pad, and the centers of the bearing steel pad and the loading steel pad are aligned with the square rock specimen;

[0044] S300, connect the sensor and stabilize it;

[0045] Specifically, the sensor is connected to the intelligent static strain gauge distribution box. The sensor includes a pressure gauge and a displacement sensor. The computer to be tested and the power supply are turned on. The intelligent static strain gauge software is opened to initialize the parameters. Before the test begins, the initial stable readings of the pressure gauge and the displacement sensor are observed. Each meter is read once every 10 minutes. If the reading remains unchanged for three consecutive times, the pressure test can be started. This reading is used as the initial reading value of each meter, and the load is ready to be recorded.

[0046] S400, start loading test;

[0047] Specifically, the jack is opened to load the minimum size of the rock specimen by loading the steel pad. The load is applied step by step according to the determined load value. The load is applied in 10 levels. The first level is 1 / 5 of the estimated design load, and each subsequent level is 1 / 10 of the estimated design load. Single-cycle loading is adopted. Within the first hour of each level of load, the pressure on the rock specimen and the displacement generated are recorded and measured at intervals of 5min, 10min, 15min, 15min, and 15min. Thereafter, it is recorded every 30min. During loading, the pressure head should be perpendicular to the bedding of the rock specimen. During each load increase, the load is loaded at a uniform speed until the specimen is destroyed. The load number displayed by the intelligent static strain gauge is recorded, and the phenomena occurring during the pressurization process and the specimen after destruction are described and recorded in the record table.

[0048] S500, terminate loading;

[0049] Specifically, when one of the following phenomena occurs, the rock specimen can be considered to have reached failure and loading can be terminated: the soil around the loading steel pad or the bearing steel pad is obviously extruded laterally, bulged, or cracked; under a certain level of load, the displacement rate cannot reach the stability standard within 24 hours; the total load has reached more than twice the design requirement value;

[0050] As a preferred embodiment of this test method, it also includes:

[0051] S600, observe the rebound value of rock specimen;

[0052] Specifically, when the rebound value of the rock specimen needs to be observed, the unloading amount of each level of the jack is twice the loading increment, and the pressure on the rock specimen and the displacement generated are recorded and measured every 10 minutes. Each level of load lasts for 1 hour, and the observation is carried out for 3 hours after all the loads are unloaded. The observation time intervals are 10 minutes, 20 minutes, 30 minutes, 1 hour and 1 hour.

[0053] As a preferred embodiment of this test method, it also includes:

[0054] S101, collecting rock samples;

[0055] Specifically, this step is performed before S100. After determining the plane position and depth of the required test point, a vertical test hole is first excavated around the test point by artificial digging, and then a concrete retaining wall is poured around the pit according to the design requirements. After the concrete retaining wall reaches the design strength, the pit is continued to be excavated around the test point according to the design requirements, and the rock mass at the test point is excavated into a rock specimen. The disturbed rock mass on the working surface of the rock specimen should be cleared as much as possible, and the depth of the clearing depends on the degree of disturbance of the rock mass. At the same time, the working surface of the rock specimen is repaired and leveled, a sump is set around the rock specimen, and a support ring is built around it with bricks;

[0056] S102, trimming and recording rock specimen information;

[0057] Specifically, this step is performed after S101 and before S100, verifying the name of the rock specimen, describing the specimen color, particles, bedding, joints and cracks, and weathering degree, and writing them into the record sheet, measuring the distance between the loading points of the rock specimen with an electronic vernier caliper, and recording them in the table, and using tools such as a geological hammer to trim irregular specimens that are difficult to place stably under the indenter;

[0058] It will be easily understood by those skilled in the art that 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A rock mass lateral load flat plate test system, characterized in that: include A loading module for applying a load to a rock specimen, a detection module for detecting pressure and displacement parameters, a fixing module for fixing the loading module and the detection module, and a data module for storing pressure and displacement parameters; The fixing module comprises a loading frame, the loading module comprises a bearing steel pad (4), a loading steel pad (5), a guide rod (7) and a jack (9), the bearing steel pad (4) is fixed on the loading frame, the guide rod (7) is slidably connected to the loading frame, the loading steel pad (5) is fixed to the end of the guide rod (7), and is arranged parallel to the bearing steel pad (4), both of which are located inside the loading frame, and the two ends of the jack (9) are respectively fixed on the loading frame and the loading steel pad (5), and are used to push the loading steel pad (5) to apply load to the rock specimen; The detection module comprises a pressure gauge (13) and a displacement sensor (14); the pressure gauge (13) is respectively arranged on the bearing steel pad (4) and the loading steel pad (5); the displacement sensor (14) is arranged on the rock specimen; the pressure gauge (13) and the displacement sensor (14) are respectively in signal communication with the data module.

2. A rock mass lateral load flat plate test system according to claim 1, characterized in that: The loading frame includes a load-bearing beam (2) located at an upper portion, the loading module includes a fixing bracket (3), the fixing bracket (3) is fixed on the load-bearing beam (2), and the load-bearing steel pad (4) is fixed on the fixing bracket (3).

3. A rock mass lateral load plate test system according to claim 1, characterized in that: The loading frame comprises a level bubble (6), which is fixed on the loading frame and is used for leveling the fixing module.

4. A rock mass lateral load plate test system according to claim 1, characterized in that: The loading frame comprises a loading beam (11), the loading beam (11) is arranged at the bottom of the loading frame, the jack (9) is fixed on the loading beam (11), and the guide rod (7) is slidably connected to the loading beam (11).

5. A rock mass lateral load plate test system according to claim 4, characterized in that: The loading module comprises a guide sleeve (10), a seat tube clamp (15) and a jack mounting seat (8); the guide sleeve (10) is fixed on the loading beam (11); the guide sleeve (10) corresponds to the position and number of the guide rod (7); the two are slidably connected; the seat tube clamp (15) is bolted to the guide rod (7) for fixing the guide rod (7); the jack mounting seat (8) is fixed to the loading steel plate (5) for fixing the jack (9).

6. A rock mass lateral load plate test system according to claim 1, characterized in that: The invention comprises a threaded bottom hole (16) and a pressure head (17), wherein the threaded bottom hole (16) is provided on the bearing steel pad (4) and the loading steel pad (5) and is used for screwing and fixing the pressure head (17); the pressure head (17) is fixed toward one side of the rock specimen and is used for applying pressure to the rock specimen; the pressure gauge (13) is fixed on the pressure head (17).

7. A rock mass lateral load flat plate test method, characterized in that: The rock mass lateral load plate test system according to any one of claims 1 to 6 is used to implement the method, comprising the following steps: S100, adjusting the pressure testing machine to a minimum load, which is 5 kN or 2% of the maximum load. The minimum value of the two is selected during the actual test. After the adjustment is completed, the pressure testing machine is left to stand until the vertical load force of the pressure testing machine stabilizes. S200, fixing the rock specimen, putting a square loading frame on the outside of the rock specimen, then fixing the rock specimen, and leveling and fixing the square loading frame; S300: Connect the sensor and stabilize it. Connect the sensor to the intelligent static strain gauge distribution box. Observe the initial stable reading of the sensor. Read each gauge once at a fixed interval. After three consecutive readings remain unchanged, use this reading as the initial reading value of each gauge. S400: Start the loading test. Apply load to the rock specimen step by step. The load is applied in 10 levels. The first level is 1 / 5 of the estimated design load, and each subsequent level is 1 / 10 of the estimated design load. Single-cycle loading is used. Within the first hour of each load level, the pressure and displacement of the rock specimen are recorded and measured at intervals of 5 minutes, 10 minutes, 15 minutes, 15 minutes, and 15 minutes. Thereafter, the records are recorded every 30 minutes. During each load increase, the load is applied at a uniform speed until the specimen fails. The load number displayed by the intelligent static strain gauge is recorded. The phenomena during the pressurization process and the appearance of the specimen after failure are recorded in the record sheet. S500, terminate loading. When the following phenomena occur, the rock specimen has reached failure and loading can be terminated. The phenomena include obvious lateral extrusion, bulging or cracking of the soil around the loading steel pad or the bearing steel pad; under a certain level of load, the displacement rate cannot reach the stability standard within 24 hours; the total load has reached more than twice the design requirement value.

8. A rock mass lateral load flat plate test method according to claim 7, characterized in that: include: S600, observe the rebound value of the rock specimen, unload the load on the rock specimen, and the unloading amount at each level is twice the amount added when increasing the load. Record and measure the pressure on the rock specimen and the displacement generated every 10 minutes. Each level of load lasts for 1 hour. After all loads are unloaded, observe for 3 hours. The observation time intervals are 10 minutes, 20 minutes, 30 minutes, 1 hour and 1 hour.

9. A rock mass lateral load flat plate test method according to claim 8, characterized in that: include: S101, collecting rock samples. This step is performed before S100. After determining the plane position and depth of the required test point, vertical test holes are first excavated around the test point by manual digging. Concrete retaining walls are poured around the pit according to design requirements. After the concrete retaining walls reach the design strength, the pit is further excavated around the test point according to design requirements. The rock mass at the test point is excavated into a rock specimen. The disturbed rock mass on the working surface of the rock specimen is cleaned and the working surface of the rock specimen is repaired and leveled. A water collection pit is set around the rock specimen, and a support ring is built around the perimeter with bricks. S102, trim and record rock specimen information. This step is performed after S101 and before S100. Verify the name of the rock specimen, describe the specimen color, particles, bedding, joints and cracks, and weathering degree, and write them in the record table. Use an electronic vernier caliper to measure the distance between the loading points of the rock specimen and record it in the table. For irregular specimens that are difficult to place stably under the indenter, use a geological hammer tool to trim them.

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