Slope rock-soil body in-situ compression-shear test device and test method

Abstract

The invention discloses a slope rock-soil body in-situ compression-shear test device and test method, and relates to the technical field of rock-soil body in-situ shear tests, the device comprises a fixed base, a multi-link structure, a pressure applying assembly, a sensor, an analog-to-digital converter and an industrial computer. The test method comprises the steps of soil sample preparation, device installation, data acquisition and pressurization, shear failure recording, data analysis and parameter calculation, and determination of soil shear strength parameters through an on-site in-situ test. In the test process, a laser scanner is used for carrying out three-dimensional modeling on the shear surface, the area and the inclination angle of the shear surface are accurately calculated, and the result accuracy is verified by combining machine learning and finite element analysis. According to the invention, sampling disturbance can be avoided, test precision can be improved, multi-angle shear characteristic research can be realized, reliability can be improved, test cost can be reduced, efficiency can be improved through intelligent data acquisition and analysis, scientific basis can be provided for slope stability analysis and support design, and the device is suitable for various complex geological conditions, and has significant engineering application value.

Description

Technical Field

[0001] The present invention relates to the technical field of in-situ shear tests of rock and soil masses, and particularly relates to an in-situ compression-shear test device and test method for slope rock and soil masses. Background Art

[0002] The problem of slope stability is an important research content in the field of geotechnical engineering, and the accuracy of its evaluation results is directly related to the safety and economy of slope engineering. In the analysis of slope stability, the shear strength parameters of slope rock and soil masses play a decisive role in the analysis of slope stability and the design of support structures. The current national standards put forward corresponding suggestions on the selection of test methods for different types of slope rock and soil masses:

[0003] 1. Saturated soft soil: It is advisable to adopt direct shear quick shear, triaxial unconsolidated undrained test or vane shear test; 2. Clay and silty clay: It is advisable to adopt direct shear consolidated quick shear or triaxial consolidated undrained shear; 3. Silt, sand and gravel: It is advisable to adopt effective stress strength index; 4. Rock mass structural plane: The shear strength is usually determined by indoor tests combined with similar engineering experience.

[0004] However, the above traditional test methods have the following prominent problems in practical applications, which affect the accuracy and reliability of test results:

[0005] 1. Disturbance problem of rock and soil samples: During the process of drilling and sampling and transporting to the laboratory, rock and soil samples are easily disturbed. Especially for highly sensitive soils such as saturated soft soil, it is extremely easy to cause structural damage due to external forces, resulting in deviation of test data and difficulty in reflecting the true mechanical properties.

[0006] 2. Difficulty in obtaining undisturbed samples: For soils with coarser particles such as silt, sand and gravel, it is very difficult to obtain complete undisturbed samples during the drilling process. Especially for gravel, due to the presence of large-sized stone blocks, regular samples cannot be made, further limiting the applicability of laboratory tests.

[0007] 3. Sampling limitation of rock mass structural plane: During the drilling process, the rock mass structural plane is easily disturbed or damaged. Generally, drilling can only obtain rock masses with better cementation (such as calcareous, siliceous, ferruginous cementation), while it is difficult to obtain complete samples of argillaceous cemented structural planes that are unfavorable to slope stability, resulting in the test results being unable to fully reflect the true situation of the slope.

[0008] 4. Applicability limitation of in-situ vane shear test: Although the in-situ vane shear test is applicable to soft clay, it is not applicable to hard plastic cohesive soil and soil containing gravel and debris. Conducting tests under these conditions may damage the vane head, thereby affecting the accuracy of test results.

[0009] 5. Shearing plane problem of in-situ large shear test: The shearing plane of the in-situ large shear test is limited between the upper and lower boxes. Such an artificially set shearing plane is often not the actual weakest plane of the soil mass. Therefore, the obtained shear strength index is usually on the high side and cannot truly reflect the shear performance of the slope rock and soil mass. Summary of the Invention

[0010] To solve the above problems, the present invention provides a device and method for in-situ compression shear test of slope rock and soil mass, aiming to solve the problems such as disturbance, sampling difficulty, and test data deviation existing in the traditional test methods.

[0011] The technical solution adopted by the present invention is as follows:

[0012] An in-situ compression shear test device for slope rock and soil mass, which includes a fixed base horizontally fixed on the foundation soil through anchor bolts. A pressure application component is installed on the fixed base through a multi-link structure, and the pressure application component extends to the side of the test soil sample to apply pressure to the test soil sample. The in-situ compression shear test device for slope rock and soil mass further includes a pressure sensor, an inclination sensor, a laser displacement rangefinder, a laser scanner, an analog-to-digital converter, and an industrial computer. The pressure sensor and the inclination sensor are installed on the pressure application component, the laser scanner and the analog-to-digital converter are independently installed near the test soil sample, the pressure sensor, the inclination sensor, and the laser displacement rangefinder are connected to the analog-to-digital converter by wire, and the industrial computer is connected to the analog-to-digital converter, the laser scanner, and the pressure application component by wire.

[0013] Further, the fixed base is a rectangular plate structure, with a spirit level embedded at the center of its top surface, and mounting holes for the anchor bolts to pass through are provided at its four corners.

[0014] Further, the multi-link structure includes three first support rods arranged in a triangle. One end of each first support rod is installed on the fixed base through a hinge seat, and the other ends of the three first support rods converge at a point and are hinged to one end of a third support rod. The other end of the third support rod is installed with the pressure application component. The multi-link structure further includes a second support rod. One end of the second support rod is hinged to the middle section of the third support rod, and the hinge point position can be changed. Its other end is hinged to one of the three first support rods.

[0015] Further, the pressure application component includes a hydraulic jack installed at the other end of the third support rod and a hydraulic servo system connected to the hydraulic jack by a pipeline. A pressure plate is installed on the telescopic rod of the hydraulic jack. The hydraulic servo system is connected to the industrial computer by wire.

[0016] An in-situ compression shear test method for slope rock and soil mass, which is based on the above-mentioned in-situ compression shear test device for slope rock and soil mass, and is characterized by including the following steps:

[0017] S1 Soil sample preparation: Excavate a platform on the slope and fabricate 3 groups of test soil samples in the shape of a frustum of a pyramid; trim and press the upper side of the slope of each group of test soil samples, with the inclination angles of the pressure surfaces of each group of soil samples differing by 10° - 15°, ensuring a smooth fit with the pressure plate.

[0018] S2 Device installation: Install a fixed base on the foundation soil and adjust the fixed base to be horizontal; install a multi-link structure and a pressure application component based on the fixed base, and adjust the angle of the pressure application component through the multi-link structure; turn on the inclination sensor, laser displacement rangefinder, and laser scanner to ensure the normal operation of the equipment.

[0019] S3 Data acquisition and pressure application: Start the hydraulic servo system through an industrial computer to apply pressure uniformly, and record the pressure data, displacement data of the test soil sample, and inclination data of the pressure application component in real time.

[0020] S4 Shear failure and recording: Continuously apply pressure until the test soil sample undergoes shear failure, record the maximum pressure data and the displacement data of the test soil sample at the time of failure; measure the geometric parameters of the shear surface with a laser scanner, and calculate the shear surface area and inclination angle.

[0021] S5 Data analysis and parameter calculation: Calculate the compressive stress and shear stress on the shear surface of the test soil sample through an industrial computer, fit the σ-τ straight line, and extract the internal friction angle and cohesion.

[0022] S6 Test termination and removal: Stop the test after the data analysis system issues a test termination message; remove the test device and clean the site.

[0023] Furthermore, during the S3 data acquisition and pressure application process, the pressure sensor measures the pressure data F applied by the hydraulic jack, the inclination sensor measures the inclination data θ1 of the pressure plate, the laser displacement rangefinder measures the displacement data S of the test soil mass during the pressure application process, and the pressure data F, inclination data θ1, and displacement data S of the test soil mass are converted into digital signals through an analog-to-digital converter and transmitted to the industrial computer.

[0024] Furthermore, S4 shear failure and recording include the following steps:

[0025] Step 4.1, continuously apply pressure until the test soil sample undergoes shear failure, record the pressure and displacement changes during the pressure application process until the test soil sample undergoes shear failure, generate a curve of the pressure of the pressure plate and the displacement change of the test soil mass during the pressure application process, and record the maximum pressure F max and the displacement S at the time of failure max ;

[0026] Step 4.2, after the test soil sample is sheared and damaged, remove the pressure plate, remove the soil above the shear surface, use a laser scanner to perform three-dimensional modeling on the shear surface, measure the side lengths a, b, c, d and the diagonal length L of the shear surface, and calculate the shear surface area A;

[0027] The calculation formula for the shear surface area A is as follows:

[0028] A = [P1×(P1 - a)×(P1 - b)×(P1 - L)] 0.5 + [P2×(P2 - c)×(P2 - d)×(P2 - L)] 0.5

[0029] In the formula, P1 and P2 are intermediate variables, P1 = (a + b + L) / 2, P2 = (c + d + L) / 2;

[0030] Step 4.3, attach the pressure plate to the shear surface, measure the inclination angle θ2 of the shear surface normal, calculate the inclination angle α of the shear surface, and the included angle β between the shear surface and the pressure of the pressure plate;

[0031] The calculation formula for the inclination angle α of the shear surface is as follows:

[0032] α = 90° - θ2

[0033] The calculation formula for the included angle β between the shear surface and the pressure of the pressure plate is as follows:

[0034] β = θ1 - α.

[0035] Furthermore, S5 data analysis and parameter calculation includes the following steps:

[0036] Step 5.1, calculate the normal stress σ and shear stress τ on the shear surface:

[0037]

[0038] In the formula, σ represents the normal stress on the shear surface; F n is the normal component of the maximum pressure F applied by the pressure plate max resolved along the shear surface; A is the shear surface area; β is the included angle between the shear surface and the pressure of the pressure plate; F max is the maximum pressure during the pressurization process; τ represents the tangential stress on the shear surface; F t is the tangential component of the maximum pressure F applied by the pressure plate max resolved along the shear surface;

[0039] Step 5.2, conduct compression-shear tests on test soil samples with different inclination angles to obtain multiple groups of σ i 、τ i data;

[0040] Step 5.3: Use a multi-parameter fitting model to fit the σ-τ straight line and calculate the internal friction angle φ and cohesion c of the soil mass.

[0041] The calculation formula is: τ = c + σ·tanφ;

[0042] In the formula, φ is the angle between the straight line and the abscissa of the fitted σ-τ straight line, that is, the internal friction angle; c is the intersection of the straight line and the ordinate of the fitted σ-τ straight line, that is, the cohesion.

[0043] Furthermore, the in-situ compression-shear test method for slope rock and soil masses further includes:

[0044] S7 Machine learning and numerical simulation: Import the pressure data F applied by the hydraulic jack, the displacement data S of the test soil mass, the inclination angle data θ1 of the pressure plate, the inclination angle θ2 of the normal line of the shear plane, the shear plane area A, the compressive stress σ on the shear plane, and the shear stress τ on the shear plane in the historical test data into the machine learning model to train the algorithm for predicting the shear failure mode and mechanical properties of the soil mass; then combine finite element analysis to verify the accuracy of the test results and conduct slope stability evaluation.

[0045] The beneficial effects of the present invention are:

[0046] 1. Intelligence and automation: Through the intelligent sensor network and the automatic control system, realize the real-time acquisition, transmission and analysis of test data, and reduce human errors.

[0047] 2. High-precision measurement: Use laser scanning technology to perform three-dimensional modeling on the shear plane and accurately calculate the shear plane area.

[0048] 3. Multi-source data fusion: Combine data such as pressure, displacement, and inclination angle to comprehensively analyze the shear failure process of the soil mass.

[0049] 4. Improve the test accuracy and reliability: The on-site shear test shears and fails along the weakest surface of the specimen, avoiding the errors caused by shearing along the defined shear plane.

[0050] 5. Strong adaptability: The device is designed flexibly and is suitable for shear tests on different slope rock and soil masses and rock mass structural planes, and can effectively cope with the test problems brought by difficult sampling strata and sampling disturbance.

[0051] 6. Machine learning and numerical simulation: Verify the accuracy of the test results through historical test data and finite element analysis.

[0052] In summary, the in-situ compression-shear test device and test method for slope rock and soil masses provided by the present invention have significant advantages such as high precision, low cost, high efficiency, and strong adaptability, providing reliable technical support for slope stability analysis and support design. Description of the Drawings

[0053] Figure 1 Schematic diagram of the in-situ compression-shear test device for slope rock and soil mass of the present invention;

[0054] Figure 2 Flow chart of the in-situ compression-shear test method for slope rock and soil mass of the present invention;

[0055] Figure 3 Schematic diagram of the curve of the pressure of the pressure plate varying with displacement of the present invention;

[0056] Figure 4 Schematic diagram of the shear plane of the present invention;

[0057] Figure 5 Schematic diagram of the decomposition of the pressure of the pressure plate along the shear plane of the present invention;

[0058] Figure 6 Schematic diagram of the fitting straight line of the shear strength of the test soil mass at different compression-shear angles of the present invention;

[0059] In the figure, 1 - foundation soil, 2 - fixed base, 3 - spirit level, 4 - anchor bolt, 5 - multi-link structure, 6 - first support rod, 7 - second support rod, 8 - third support rod, 9 - pressure application assembly, 10 - hydraulic jack, 11 - pressure plate, 12 - hydraulic servo system, 13 - test soil sample, 14 - shear plane. Specific embodiments

[0060] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0061] For ease of explanation, spatial relative terms such as "upper", "lower", "left", "right", etc. can be used here to describe the relationship between one element or feature shown in the figure and another element or feature. It should be understood that in addition to the orientation shown in the figure, the spatial terms are intended to include different orientations during the use or operation of the device. For example, if the device in the figure is inverted, the element described as being "below" other elements or features will be located "above" other elements or features. Therefore, the exemplary term "lower" can include both upper and lower orientations. The device can be positioned in other ways, and the spatial relative descriptions used here can be interpreted accordingly.

[0062] To solve the problems such as disturbance, difficult sampling, and test data deviation existing in the traditional test method, an in-situ compression-shear test device for slope rock and soil mass is proposed in this embodiment. As Figure 1As shown in the figure, the in-situ compression-shear test device for slope rock and soil mass includes a fixed base 2 horizontally fixed on the foundation soil 1 by anchor bolts 4. A pressure application assembly 9 is installed on the fixed base 2 through a multi-link structure 5, and the pressure application assembly 9 extends to the side of the test soil sample 13 and can apply pressure to the test soil sample 13.

[0063] As Figure 1 shown in the figure, the fixed base 2 in this embodiment is a rectangular plate structure. A spirit level 3 is embedded at the center of its top surface, and mounting holes for the anchor bolts 4 to pass through are provided at its four corners; the fixed base 2 is used to support the entire test device and is fixed to the foundation soil 1; the spirit level 3 is used to detect whether the test base is horizontal; the anchor bolts 4 can firmly fix the fixed base 2 on the foundation soil 1; by ensuring the horizontality of the test device through the fixed base 2, a stable reaction force foundation is provided for the force application of the subsequent pressurization system.

[0064] As Figure 1 shown in the figure, the multi-link structure 5 in this embodiment includes three first support rods 6 arranged in a triangle. One end of the first support rod 6 is installed on the fixed base 2 through a hinge seat. The other ends of the three first support rods 6 converge at a point and are hinged to one end of the third support rod 8. The other end of the third support rod 8 is installed with the pressure application assembly 9; the multi-link structure 5 further includes a second support rod 7. One end of the second support rod 7 is hinged to the middle section of the third support rod 8, and the hinge point position can be changed. Its other end is hinged to one of the three first support rods 6. Through the multi-link structure 5, the functions of support and angle adjustment are provided, so that the pressure application assembly 9 can flexibly adapt to the test requirements of different inclinations.

[0065] As Figure 1 shown in the figure, the pressure application assembly 9 in this embodiment includes a hydraulic jack 10 installed at the other end of the third support rod 8, and a hydraulic servo system 12 connected to the hydraulic jack 10 through a pipeline; a pressure plate 11 is installed on the telescopic rod of the hydraulic jack 10. Among them, the hydraulic servo system 12 is used to provide stable pressurization power; the hydraulic jack 10 is used to apply pressure; the pressure plate 11 is in direct contact with the test soil sample 13 to apply pressure; the pressure application assembly 9 can apply pressure to the test soil mass at different angles through the multi-link structure 5 until the soil mass undergoes shear failure.

[0066] Further, the in-situ compression-shear test device for slope rock and soil mass further includes a pressure sensor, an inclination sensor, a laser displacement rangefinder, a laser scanner, an analog-to-digital converter, and an industrial computer. The pressure sensor is installed on the hydraulic jack 10, the inclination sensor is installed on the connecting pipe between the pressure plate 11 and the hydraulic jack 10, the laser scanner and the analog-to-digital converter are independently installed near the test soil sample 13, the pressure sensor, the inclination sensor, and the laser displacement rangefinder are connected to the analog-to-digital converter by wire, and the industrial computer is connected to the analog-to-digital converter, the laser scanner, and the pressure application assembly 9 by wire. The hydraulic servo system 12 is connected to the industrial computer by wire.

[0067] Among them, the pressure sensor is used to measure the pressure applied by the pressure plate 11; the inclination sensor is used to measure the inclination of the pressure plate 11; the laser displacement rangefinder is used to measure the displacement of the test soil body during the pressure application process; the pressure data, the inclination data, and the displacement data of the test soil body are converted into digital signals by the analog-to-digital converter and transmitted to the industrial computer; the laser scanner is used for three-dimensional modeling of the shear surface and calculating the shear surface area; the industrial computer is used to process and analyze the data collected by the sensors in real time, and to control the hydraulic servo system 12; by collecting data such as pressure, displacement, and inclination during the test process in real time, it provides accurate basic data for subsequent analysis, and at the same time realizes the automatic control of the test process, reduces human errors, and improves the test accuracy.

[0068] Based on the above in-situ compression-shear test device for slope rock and soil mass, this embodiment also proposes an in-situ compression-shear test method for slope rock and soil mass, as Figure 2 shown, the in-situ compression-shear test method for slope rock and soil mass includes the following steps:

[0069] S1 Soil sample preparation:

[0070] First, excavate a test platform on the test slope;

[0071] Then, make 3 groups of test soil samples 13 in the shape of a frustum of a pyramid on the soil body of the same geological layer:

[0072] The bottom and top surfaces of the test soil sample 13 are similar quadrilaterals, and the side surfaces are trapezoids; the height of the frustum of the pyramid is 20 cm to 40 cm; one of the axes of the test soil sample 13 is consistent with the slope direction.

[0073] Finally, trim the pressure application surface on the uphill side of each group of test soil samples 13:

[0074] The inclination angles of the pressure application surfaces of each group of soil samples differ by 10° to 15°; the pressure application surfaces are repaired and leveled to ensure close fit with the pressure plate 11.

[0075] Fabricate a test soil sample 13 in the shape of a frustum of a square pyramid to prevent the soil sample from breaking at the bottom during the compression-shear process. Set pressure surfaces at different inclination angles to study the mechanical properties of the soil mass at different shear angles. Ensure that the test soil sample 13 is undisturbed and can reflect the true mechanical properties of the soil mass.

[0076] Installation of S2 device:

[0077] First, install the fixed base 2 on the upper slope side of the test soil sample 13, and adjust the spirit level bubble 3 to make the base horizontal; tighten the anchor bolts 4 to firmly fix the fixed base 2 on the foundation soil 1.

[0078] Then, as shown in Figure 1 , install the three first support rods 6 of the multi-link structure 5. After the installation of the first support rods 6 is completed, then install the second support rod 7, the third support rod 8, and the pressure application component 9; after the installation of both the multi-link structure 5 and the pressure application component 9 is completed, adjust the angle of the pressure application component 9 through the multi-link structure 5 to make the pressure plate 11 closely fit the pressure surface of the test soil sample 13.

[0079] Finally, install the pressure sensor, inclination sensor, laser displacement rangefinder, laser scanner, analog-to-digital converter, and industrial computer; turn on the inclination sensor, laser displacement rangefinder, and laser scanner to ensure the normal operation of the equipment.

[0080] The fixed base 2 ensures the stability of the test device and provides a reliable reaction force basis for subsequent pressurization. The multi-link structure 5 and the pressure application component 9 work together to ensure that the pressurization direction and angle meet the test requirements. The pressure sensor, inclination sensor, and laser displacement rangefinder collect test data in real time, providing accurate basic information for subsequent analysis.

[0081] S3 Data acquisition and pressurization:

[0082] Start the hydraulic servo system 12, and control the hydraulic servo system 12 of the pressure application component 9 through the industrial computer to make the hydraulic jack 10 of the pressure application component 9 uniformly pressurize the test soil sample 13.

[0083] During the data acquisition and pressurization process, record the following data during pressurization in real time:

[0084] The pressure sensor measures the pressure data F applied by the hydraulic jack 10, the inclination sensor measures the inclination data θ1 of the pressure plate 11, and the laser displacement rangefinder measures the displacement data S of the test soil mass during pressurization; the pressure data F, the inclination data θ1, and the displacement data S of the test soil mass are converted into digital signals through the analog-to-digital converter and transmitted to the industrial computer.

[0085] Apply uniform pressure to simulate the stress conditions under actual engineering conditions. Collect pressure, displacement, and inclination data in real time to comprehensively record the stress and deformation process of the soil mass.

[0086] S4 Shear failure and recording:

[0087] Continuously apply pressure until the test soil sample 13 undergoes shear failure, record the maximum pressure data and the displacement data of the test soil sample 13 at the time of failure; measure the geometric parameters of the shear surface 14 with a laser scanner and calculate the area of the shear surface 14; the specific implementation steps are as follows:

[0088] Step 4.1, continuously apply pressure until the test soil sample 13 undergoes shear failure, record the changes in pressure and displacement during the pressure application process until the test soil sample 13 undergoes shear failure, generate the curve of the pressure of the pressure plate 11 and the displacement change of the test soil mass during the pressure application process, and the change curve is as Figure 3 shown. Based on the maximum pressure F max recorded in the change curve and the displacement S max .

[0089] After the test soil sample 13 undergoes shear failure in Step 4.2, remove the pressure plate 11; remove the soil mass above the shear surface 14 and use a laser scanner to perform three-dimensional modeling on the shear surface 14. The shear surface 14 is as Figure 4 shown. Measure the side lengths a, b, c, d and the diagonal length L of the shear surface 14 and calculate the area A of the shear surface 14.

[0090] Among them, the calculation formula for the cross-sectional area A is as follows:

[0091] A = [P1×(P1 - a)×(P1 - b)×(P1 - L)] 0.5 +[P2×(P2 - c)×(P2 - d)×(P2 - L)] 0.5

[0092] In the formula, P1 and P2 are intermediate variables, P1 = (a + b + L) / 2, P2 = (c + d + L) / 2;

[0093] In Step 4.3, attach the pressure plate 11 to the shear surface 14, measure the normal inclination angle θ2 of the shear surface 14, calculate the inclination angle α of the shear surface 14, and the included angle β between the shear surface 14 and the pressure of the pressure plate 11.

[0094] The calculation formula for the inclination angle α of the shear surface 14 is as follows:

[0095] α = 90° - θ2

[0096] The calculation formula for the included angle β between the shear surface 14 and the pressure of the pressure plate 11 is as follows:

[0097] β = θ1 - α

[0098] Record the key parameters of soil shear failure, which can provide a basis for subsequent mechanical analysis. By using laser scanning technology to accurately measure the geometric characteristics of the shear plane 14, the data accuracy can be ensured. Calculate the included angle between the inclination angle of the shear plane 14 and the pressure, laying a foundation for the calculation of mechanical parameters.

[0099] S5 Data analysis and parameter calculation:

[0100] Calculate the compressive stress and shear stress on the shear plane 14 of the test soil sample 13 through an industrial computer, fit the σ-τ straight line, and extract the internal friction angle and cohesion; the specific implementation steps are as follows:

[0101] Step 5.1, the schematic diagram of the decomposition of the pressure of the pressure plate 11 along the shear plane 14 is as Figure 5 shown. First, calculate the compressive stress σ and shear stress τ on the shear plane 14:

[0102]

[0103] In the formula, σ represents the normal stress on the shear plane 14; F n is the maximum pressure F applied by the pressure plate 11 max decomposed along the shear plane into the normal component; A is the area of the shear plane 14; β is the included angle between the shear plane 14 and the pressure of the pressure plate 11; F max is the maximum pressure during the pressurization process; τ represents the tangential stress on the shear plane 14; F t is the maximum pressure F applied by the pressure plate 11 max decomposed along the shear plane into the tangential component.

[0104] Step 5.2, conduct compression-shear tests on test soil samples 13 with different inclination angles to obtain multiple groups of σ i , τ i data;

[0105] Step 5.3, use a multi-parameter fitting model to fit the σ-τ straight line, and the σ-τ straight line is as Figure 6 shown; then, calculate the internal friction angle φ and cohesion c of the soil;

[0106] The calculation formula is: τ = c + σ·tanφ;

[0107] In the formula, φ is the included angle between the fitted σ-τ straight line and the abscissa, that is, the internal friction angle; c is the intersection point of the fitted σ-τ straight line and the ordinate, that is, the cohesion.

[0108] By fitting the σ-τ straight line with multiple groups of test data, extract the key mechanical parameters of the soil, that is, the internal friction angle and cohesion, so that data analysis and parameter calculation can provide accurate shear strength indexes for slope stability analysis.

[0109] S6 Test termination and disassembly:

[0110] After the data analysis system issues the test termination information, stop the test. Dismantle the test device and clean up the site. Ensure the safe end of the test and avoid affecting the slope environment.

[0111] The in-situ compression-shear test method for slope rock and soil mass realizes the in-situ test of the shear strength of slope rock and soil mass through the above steps, specifically including soil sample preparation, device installation, data acquisition, shear failure record, data analysis, numerical simulation and test termination. Each step has a clear function and jointly constitutes a complete test process; this method can effectively solve problems existing in traditional tests such as sampling disturbance and shear plane deviation, and provides scientific and reliable technical support for slope stability analysis.

[0112] In addition, the in-situ compression-shear test method for slope rock and soil mass can also be combined with numerical simulation technology to verify the accuracy of test results through finite element analysis and provide more comprehensive mechanical parameters.

[0113] Specifically, import the pressure data F applied by the hydraulic jack 10 in historical test data, the displacement data S of the test soil mass, the inclination angle data of the pressure plate 11, the inclination angle of the normal line of the shear plane 14, the area A of the shear plane 14, the compressive stress on the shear plane 14, and the shear stress on the shear plane 14 into the machine learning model to train the algorithm for predicting the shear failure mode and mechanical properties of the soil mass; then combine finite element analysis to verify the accuracy of the test results and conduct slope stability evaluation.

[0114] Use the machine learning model to mine data laws and improve the understanding of the mechanical properties of the soil mass. Verify the reliability of the test results through finite element analysis and provide a scientific basis for slope stability assessment.

[0115] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. An in-situ compression and shear test device for slope rock and soil, characterized in that: The in-situ compression and shear test device for slope rock and soil comprises a fixed base horizontally fixed on foundation soil by anchor bolts, a pressure component is installed on the fixed base by a multi-link structure, and the pressure component extends to the side of the test soil sample and can apply pressure to the test soil sample; the in-situ compression and shear test device for slope rock and soil also comprises a pressure sensor, an inclination sensor, a laser displacement rangefinder, a laser scanner, an analog-to-digital converter, and an industrial computer; the pressure sensor and the inclination sensor are installed on the pressure component, the laser scanner and the analog-to-digital converter are independently installed near the test soil sample, the pressure sensor, the inclination sensor, the laser displacement rangefinder and the analog-to-digital converter are wired, and the industrial computer is wired to the analog-to-digital converter, the laser scanner, and the pressure component.

2. The in-situ compression and shear test device for slope rock and soil according to claim 1 is characterized in that: The fixed base is a rectangular plate structure, a level bubble is embedded in the center of the top surface, and mounting holes for matching anchor bolts to pass through are provided at the four corners.

3. The in-situ compression and shear test device for slope rock and soil according to claim 1, characterized in that: The multi-link structure includes three first support rods arranged in a triangle, one end of the first support rod is installed on a fixed base through a hinge seat, the other ends of the three first support rods converge at a point and are hinged to one end of a third support rod, and a pressure assembly is installed on the other end of the third support rod; the multi-link structure also includes a second support rod, one end of the second support rod is hinged to the middle section of the third support rod, and the position of the hinge point can be changed, and the other end is hinged to one of the three first support rods.

4. The in-situ compression and shear test device for slope rock and soil according to claim 3 is characterized by: The pressure component includes a hydraulic jack installed at the other end of the third support rod, and a hydraulic servo system connected to the hydraulic jack pipeline; a pressure plate is installed on the telescopic rod of the hydraulic jack; and the hydraulic servo system is connected to the industrial computer by wire.

5. A method for in-situ compression shear test of a slope rock and soil mass, the method for in-situ compression shear test of a slope rock and soil mass is based on the in-situ compression shear test device for a slope rock and soil mass according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1 Soil sample preparation: excavate a platform on the slope to make three groups of test soil samples in the shape of a quadrangular pyramid; trim the pressure surface on the upper side of the slope of each group of test soil samples, and the inclination angle of the pressure surface of each group of soil samples differs by 10° to 15° to ensure that it can fit smoothly with the pressure plate; S2 device installation: Install a fixed base on the foundation soil and adjust the level of the fixed base; install the multi-link structure and pressure assembly based on the fixed base, and adjust the angle of the pressure assembly through the multi-link structure; turn on the inclination sensor, laser displacement rangefinder and laser scanner to ensure the normal operation of the equipment. S3 data acquisition and pressurization: The hydraulic servo system is started by an industrial computer to apply pressure at a constant speed, and the pressure data, displacement data of the test soil sample and inclination data of the pressurizing component are recorded in real time; S4 Shear failure and recording: Continuously apply pressure until the test soil sample fails in shear, record the maximum pressure data and the displacement data of the test soil sample at failure; use a laser scanner to measure the geometric parameters of the shear surface, and calculate the shear surface area and inclination; S5 data analysis and parameter calculation: Calculate the compressive stress and shear stress on the shear surface of the test soil sample through an industrial computer, fit the σ-τ straight line, and extract the internal friction angle and cohesion; S6 Test termination and dismantling: After the data analysis system sends out the test termination information, stop the test; dismantle the test equipment and clean up the site.

6. The in-situ compression shear test method for slope rock and soil according to claim 5, characterized in that: During the S3 data collection and pressurization process, the pressure sensor measures the pressure data F applied by the hydraulic jack, the inclination sensor measures the inclination data θ1 of the pressurization plate, and the laser displacement rangefinder measures the displacement data S of the test soil during the pressurization process. The pressure data F, inclination data θ1, and displacement data S of the test soil are converted into digital signals by an analog-to-digital converter and transmitted to the industrial computer.

7. The in-situ compression shear test method for slope rock and soil according to claim 5, characterized in that: S4 shear destruction and recording, including the following steps: Step 4.1: Continue to pressurize until the test soil sample fails in shear, record the pressure and displacement changes during the pressurization process until the test soil sample fails in shear, generate a pressure plate pressure and test soil displacement change curve during the pressurization process, and record the maximum pressure F based on the change curve. max and the displacement at failure S max ; Step 4.2, after the test soil sample is sheared and damaged, the pressure plate is removed, the soil above the shear surface is removed, and a laser scanner is used to perform three-dimensional modeling of the shear surface, and the side lengths a, b, c, d and diagonal length L of the shear surface are measured to calculate the shear surface area A; The calculation formula of the cross-sectional area A is as follows: A=[P1×(P1-a)×(P1-b)×(P1-L)] 0.5 +[P2×(P2-c)×(P2-d)×(P2-L)] 0.5 Wherein, P1 and P2 are intermediate variables, P1 = (a + b + L) / 2, P2 = (c + d + L) / 2; Step 4.3, attach the pressure plate to the shear surface, measure the normal inclination angle θ2 of the shear surface, calculate the inclination angle α of the shear surface, and the pressure angle β between the shear surface and the pressure plate; The calculation formula of the shear plane inclination angle α is as follows: α=90°-θ2 The calculation formula of the angle β between the shear surface and the pressure plate is as follows: β=θ1-α.

8. The in-situ compression shear test method for slope rock and soil mass according to claim 5, characterized in that: S5 data analysis and parameter calculation, including the following steps: Step 5.1, calculate the compressive stress σ and shear stress τ on the shear surface: Where σ represents the normal stress on the shear surface; F n The maximum pressure F applied by the pressure plate max The decomposed normal component; A is the shear surface area; β is the angle between the shear surface and the pressure plate; F max The maximum pressure during the pressurization process; τ represents the tangential stress on the shear surface; F t The maximum pressure F applied by the pressure plate max Decomposed tangential components; Step 5.2: Perform compression shear tests on test soil samples with different inclination angles to obtain multiple groups of σ i , τ i data; Step 5.3, use the multi-parameter fitting model to fit the σ-τ straight line and calculate the internal friction angle φ and cohesion c of the soil; The calculation formula is: τ = c + σ·tanφ; Where φ is the angle between the fitted σ-τ straight line and the abscissa, i.e., the internal friction angle; c is the intersection of the fitted σ-τ straight line and the ordinate, i.e., the cohesion.

9. The in-situ compression shear test method for slope rock and soil mass according to claim 5, characterized in that: The in-situ compression shear test method for the slope rock and soil also includes: S7 Machine learning and numerical simulation: The pressure data F applied by the hydraulic jack of the historical test data, the displacement data S of the test soil, the inclination data θ1 of the pressure plate, the measured inclination angle θ2 of the normal line of the shear surface, the shear surface area A, the compressive stress σ on the shear surface, and the shear stress τ on the shear surface are imported into the machine learning model to train the algorithm for predicting the shear failure mode and mechanical properties of the soil; then, combined with finite element analysis, the accuracy of the test results is verified, and the slope stability evaluation is carried out.

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