Method for analyzing moraine shear characteristics by considering environmental effect

Abstract

The invention discloses a moraine shear characteristic analysis method considering an environmental effect, and belongs to the technical field of rock and soil mass mechanical tests. The moraine shearing characteristic analysis method comprises the following steps: designing and building a moraine direct shearing device considering an environmental effect; preparing a moraine test piece; under different test conditions, a moraine object direct shearing device is used for carrying out a shearing test on a moraine object test piece; acquiring shear stress and shear displacement of a moraine test piece in the shear test, fitting and analyzing moraine shear characteristics, establishing a coupling model and the like. Various environment factors such as environment temperature, consolidation pressure and rock debris content are comprehensively introduced and analyzed, moraine behaviors under different glacier environment conditions can be accurately reproduced, physical and mechanical parameters of moraine can be rapidly measured, shear characteristics of moraine can be known, systematic research on the moraine shear characteristics under complex environment conditions is achieved, and the moraine shear characteristic evaluation method has a wide application prospect. The coupling action mechanism of the environmental effect on the shear characteristic is disclosed, and a scientific basis is provided for theoretical research and practical application.

Description

Technical Field

[0001] The present invention belongs to the technical field of geotechnical mechanics tests, and particularly relates to a method for analyzing the shear characteristics of moraine considering environmental effects. Background Technique

[0002] Moraine is a mixed sediment of rock debris and ice debris formed during the movement of glaciers. Its mechanical properties play a key role in the design of geotechnical engineering in cold regions. As a special geotechnical material, the shear characteristics of moraine directly affect the stability assessment of geological disasters such as landslides and debris flows, as well as the design and construction of tunnels and slopes in cold regions. However, due to the complex component composition of moraine (such as the proportion of ice debris and rock debris) and its sensitivity to environmental conditions (such as temperature and pressure), there are still many limitations in the existing research on shear characteristics analysis. Current research on the shear characteristics of moraine mostly focuses on the mechanical behavior tests under normal temperature and pressure conditions. However, the significant temperature fluctuations in the cold region environment (such as the temperature rise during glacier retreat) may lead to the melting and refreezing of ice debris, thus significantly changing the shear strength and deformation characteristics of moraine. Ignoring these environmental effects may lead to deviations in the determination results of shear parameters, and further affect the reliability of engineering design.

[0003] Conventional direct shear test methods and devices cannot accurately simulate the complex environmental conditions experienced by moraine in cold regions, such as: the dynamic change of the temperature field; the coupling effect of ice debris and rock debris under the change of pressure and temperature; the influence of different rock debris contents on shear characteristics. Existing analysis methods mostly take a single environmental parameter (such as temperature or pressure) as a variable, lacking an analysis and prediction model for shear characteristics under the coupling action of multiple factors (such as temperature, pressure, rock debris ratio, etc.), and cannot comprehensively evaluate the influence of environmental changes on the shear behavior of moraine. In view of the fact that the shear characteristics of moraine are significantly affected by environmental effects, in order to improve the accuracy and applicability of geotechnical mechanics test results, a shear characteristics analysis method that can simultaneously consider factors such as temperature, pressure, and rock debris content is needed. This can not only make up for the deficiencies of existing research, but also provide a scientific basis for the safety design and disaster prediction of geotechnical engineering in cold regions. Summary of the Invention

[0004] Aiming at the above problems, the present invention aims to provide a method for analyzing the shear characteristics of moraine considering environmental effects, which solves the problem that conventional direct shear test methods and devices cannot accurately simulate the complex environmental conditions experienced by moraine in cold regions, resulting in the inability to comprehensively evaluate the influence of environmental changes on the shear behavior of moraine.

[0005] In order to achieve the above invention purpose, the technical solution adopted by the present invention is as follows: There is provided a method for analyzing the shear characteristics of moraine considering environmental effects, which includes the steps: S1. Design and build a direct shear device for moraine considering environmental effects; S2. Use the direct shear device for moraine to prepare moraine specimens; S3. Under different test conditions, use the direct shear device for moraine to conduct shear tests on moraine specimens; S4. Obtain the shear stress F and shear displacement S of the moraine specimens in the shear test, and fit and analyze the shear characteristics of the moraine and establish a coupling model based on the shear stress F and shear displacement S.

[0006] Further, as a specific setting method of the direct shear device for moraine considering environmental effects, the direct shear device for moraine considering environmental effects includes a control system, a vertical support frame, and a horizontal support frame; a shear box is arranged on the horizontal support frame, the shear box includes an upper shear box and a lower shear box, one side of the upper shear box is fixedly connected to the horizontal support frame through a horizontal fixing member, and a horizontal shear force servo loading member fixedly connected to the horizontal support frame is arranged on the other side of the lower shear box; a vertical pressure servo loading member is arranged on the vertical support frame directly above the shear box; A wave velocity sensor and a temperature sensor are arranged inside the shear box; a freezing cycle device is arranged outside the shear box; The horizontal shear force servo loading member, the vertical pressure servo loading member, the wave velocity sensor, the temperature sensor, and the freezing cycle device are all electrically connected to the control system.

[0007] Further, a support platform is arranged at the bottom of the horizontal support frame, and the shear box is arranged on the upper end surface of the support platform.

[0008] Further, the freezing cycle device includes a heat insulation box body sleeved on the outer wall of the shear box, the four side walls of the heat insulation box body are fixedly connected to the vertical support frame and the horizontal support frame through fixing pins, a circulating refrigeration copper pipe is arranged inside the box wall of the heat insulation box body, and the inlet end and the outlet end of the circulating refrigeration copper pipe are both communicated with a compressor located on the outer wall of the heat insulation box body through a liquid guide pipe; the compressor is electrically connected to the control system.

[0009] Further, in step S2, the method for preparing moraine specimens includes the steps: S2.1. Mix ice chips and rock chips according to the volume rock chip content and fill them into the upper shear box and the lower shear box; S2.2. Contact the vertical pressure servo loading member with the upper shear box, control the vertical pressure servo loading member to apply a vertical load through the control system, and at the same time turn on the freezing cycle device; S2.3. Keep the vertical load and temperature constant; measure the vertical displacement and wave velocity of the test data in real time until the vertical displacement and wave velocity remain stable and unchanged, then the moraine specimen consolidates, and the preparation of the moraine specimen is completed.

[0010] Further, in step S3, different test conditions include different environmental temperatures, volume rock debris contents, consolidation pressures, and vertical loads.

[0011] Further, in step S3, the method for the direct shear device of moraine to conduct a shear test on the moraine specimen is as follows: turn on the refrigeration cycle device to make the temperature of the moraine specimen in the shear box consistent with the preset test temperature; start the lateral shear force servo loading part and the vertical pressure servo loading part by the control device; the lateral shear force servo loading part applies a shear load to the moraine specimen in the shear box; the vertical pressure servo loading part applies a vertical load to the moraine specimen in the shear box until the moraine specimen fails, and the shear test is completed.

[0012] Further, in step S4, the shear characteristics of moraine include cohesion and internal friction angle; The calculation formula for cohesion is:

[0013] Among them, is a constant term, representing the basic cohesion; are all fitting coefficients, solved by experimental regression; T 、 P and V respectively represent the temperature, consolidation pressure, and volume rock debris content of the current moraine specimen; The calculation formula for the internal friction angle is:

[0014] Among them, is a constant term, representing the basic internal friction angle; are all fitting coefficients, solved by experimental regression; T 、 P and V respectively represent the temperature, consolidation pressure, and volume rock debris content of the current moraine specimen; The expression of the coupling model is:

[0015] Among them, A is the flow factor, related to temperature and the microstructure of ice; is the shear stress received by the moraine specimen; is the shear strength of the moraine specimen; n is the stress index; mis an adjustment parameter that controls the degree of transition from creep to failure; k is a coefficient related to the friction characteristics of the ice-ice interface or the ice-bedrock interface; H is the vertical displacement of the moraine specimen; Not explained; is the natural constant, H is the Heaviside function, and its specific condition is that if , its value is 0, and if , its value is 1; The shear strength of the moraine specimen is calculated as follows:

[0016] where, N is the normal stress; The stress exponent n is calculated as follows:

[0017] where, is the base stress exponent, indicating the stress exponent under standard conditions; γ is the consolidation pressure P relation coefficient; δ is the temperature T relation coefficient; T 0 is the reference temperature, referring to the melting temperature of ice; ζ is the relation coefficient of the volume rock debris content V; The coefficient related to the friction characteristics of the ice-ice interface or the ice-bedrock interface k is calculated as follows:

[0018] where, is the base friction coefficient, indicating the friction coefficient under standard conditions; E is the activation energy, indicating the influence of temperature change on the friction coefficient; R is the gas constant; is the linear relation coefficient with the consolidation pressure P ; β is the linear relation coefficient with the volume rock debris content V , indicating the influence of the rock debris volume on the friction coefficient.

[0019] The beneficial effects of the present invention are: 1. An analysis method for the shear characteristics of moraine considering environmental effects in the present invention comprehensively introduces various environmental factors such as environmental temperature, consolidation pressure, and debris content into the analysis, realizes the systematic research on the shear characteristics of moraine under complex environmental conditions, and significantly improves the accuracy and reliability of test results. By fitting and analyzing the relationships between the shear parameters of moraine, environmental temperature, debris content, and consolidation pressure, the coupling mechanism of environmental effects on shear characteristics is revealed, providing a scientific basis for theoretical research and practical applications.

[0020] 2. The present invention provides a direct shear device for moraine considering environmental effects. This device can simulate the actual stress and environmental conditions of moraine in cold regions, providing an efficient test tool for geotechnical mechanics research in cold regions. The test device is convenient to operate, the environmental parameters are controllable, and the data measurement is accurate. It can be widely applied to geotechnical engineering research, disaster prevention and control engineering, and scientific research experiments in cold regions, and has good popularization value. Description of the Drawings

[0021] Figure 1 It is a flow chart of an analysis method for the shear characteristics of moraine considering environmental effects.

[0022] Figure 2 It is a structural schematic diagram of a direct shear device for moraine considering environmental effects.

[0023] Among them, 1. Vertical support frame; 2. Horizontal support frame; 3. Horizontal shear force servo loading component; 4. Horizontal fixing component; 5. Vertical pressure servo loading component; 6. Shear box; 7. Wave velocity sensor; 8. Temperature sensor; 9. Support platform; 10. Control system; 11. Freezing cycle device; 12. Heat insulation box; 13. Circulating refrigeration copper pipe; 14. Fixed pin; 15. Compressor; 16. Liquid guide pipe. Detailed Embodiments

[0024] The following describes the detailed embodiments of the present invention to facilitate those skilled in the art of this technology to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the detailed embodiments. For those of ordinary skill in the art of this technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions created using the concept of the present invention are within the scope of protection.

[0025] As Figure 1 shown, the present invention provides an analysis method for the shear characteristics of moraine considering environmental effects, including the steps: S1. Design and build a direct shear device for moraine considering environmental effects; specifically, as Figure 2As shown in the figure, the direct shear device for moraine considering environmental effects includes a control system 10, a vertical support frame 1 and a horizontal support frame 2; a shear box 6 is arranged on the horizontal support frame 2; specifically, a support platform 9 is arranged at the bottom of the horizontal support frame 2, and the shear box 6 is arranged on the upper end surface of the support platform 9.

[0026] The shear box 6 includes an upper shear box and a lower shear box, and the cross section of the upper shear box and the lower shear box is a square with a size of 100 mm×100 mm. One side of the upper shear box is fixedly connected to the horizontal support frame 2 through a horizontal fixing member 4, and a horizontal shear force servo loading member 3 fixedly connected to the horizontal support frame 2 is arranged on the other side of the lower shear box; a vertical pressure servo loading member 5 is arranged on the vertical support frame 1 directly above the shear box 6; a wave velocity sensor 7 and a temperature sensor 8 are arranged inside the shear box 6; a freezing cycle device 11 is arranged outside the shear box 6; the horizontal shear force servo loading member 3, the vertical pressure servo loading member 5, the wave velocity sensor 7, the temperature sensor 8 and the freezing cycle device 11 are all electrically connected to the control system 10.

[0027] As a specific setting mode of the freezing cycle device 11, the freezing cycle device 11 includes a heat insulation box body 12 sleeved on the outer wall of the shear box 6. The four side walls of the heat insulation box body 12 are fixedly connected to the vertical support frame 1 and the horizontal support frame 2 through fixing pins 14. A circulating refrigeration copper tube 13 is arranged inside the box wall of the heat insulation box body 12. The inlet end and the outlet end of the circulating refrigeration copper tube 13 are both communicated with a compressor 15 located on the outer wall of the heat insulation box body 12 through a liquid guide tube 16; the compressor 15 is electrically connected to the control system 10.

[0028] The working principle of the direct shear device for moraine is as follows: the vertical support frame 1 and the horizontal support frame 2 provide the overall stability and structural support of the device to ensure the uniformity of load transfer during the test. The shear box 6 is used to prepare and place moraine specimens, and a wave velocity sensor 7 and a temperature sensor 8 are arranged inside to monitor the internal state of the specimens in real time. The vertical pressure servo loading member 5 is used to apply vertical pressure to simulate the consolidation state under actual geological conditions. The horizontal shear force servo loading member 3 is used to apply shear force to achieve precise control of the shear process. The freezing cycle device 11 can achieve precise control of the temperature range during the test to ensure the stability of the temperature field of the moraine specimens. The control system 10 records the shear stress, shear displacement, vertical displacement and wave velocity data. By controlling the refrigeration of the freezing cycle device 11, the temperature inside the shear box 6 can be precisely adjusted; the temperature sensor 8 monitors the temperature of the moraine in real time to ensure that the fluctuation range does not exceed ±0.1℃. The control system 10 collects the shear stress, shear displacement, vertical displacement and wave velocity data of the moraine in real time and transmits them to the control terminal for storage and analysis.

[0029] S2. Prepare a moraine specimen using a direct shear device for moraine; specifically, in step S2, the method for preparing a moraine specimen includes the steps: S2.1. Fill the upper shear box and the lower shear box with a mixture of ice chips and rock chips according to the volume rock chip content. S2.2. Bring the vertical pressure servo loading member 5 into contact with the upper shear box, and control the vertical pressure servo loading member 5 to apply a vertical load through the control system 10, and at the same time turn on the refrigeration cycle device 11. S2.3. Keep the vertical load and temperature constant; measure the test data of vertical displacement and wave velocity in real time until the vertical displacement and wave velocity remain stable and no longer change, then the moraine specimen is consolidated, and the preparation of the moraine specimen is completed.

[0030] In this embodiment, artificial ice chips are prepared in the laboratory. High-purity water (with an impurity content of less than 0.05%) is selected and frozen into a block of ice in a low-temperature environment (-10°C), and then the ice block is crushed into ice chips with a particle size of 0.5 - 2 mm using a crusher and stored in a -10°C freezer for later use. Moraine samples are collected from glacial deposit areas in cold regions. After cleaning and drying, rock chips with a particle size range of 0.5 - 5 mm are selected by sieving to simulate the mineral components in the moraine. According to the volume rock chip content V set in the experiment (such as 10%, 20%, 30%), the ice chips and rock chips are weighed in proportion and placed in a low-temperature mixer to be mixed evenly. The wave velocity sensor 7 and the temperature sensor 8 are installed in the shear box 6, and at the same time, the temperature in the shear box 6 is pre-cooled to the set temperature (-5°C). The mixed ice-rock mixture specimen is filled into the shear box 6 layer by layer, with each layer having a thickness of 10 mm, and a compaction tool is used to gently press to ensure that the specimen is dense and uniform. The shear box 6 is fixed to the support table 9 to ensure good fixed connection and contact between the shear box 6 and the vertical pressure servo loading member 5 and the lateral support frame 2 to avoid offset during the loading process. Apply the set consolidation pressure P (100 kpa, 200 kpa, 300 kpa, 400 kpa) through the vertical pressure servo loading member 5, and start the control system 10 to monitor the vertical displacement H and the wave velocity W. Continuously monitor under the consolidation pressure and the target temperature until the vertical displacement H and the wave velocity W are stable and no longer change. The stability criterion is that the wave velocity change rate is less than 0.5%, which is regarded as the completion of consolidation. After consolidation is completed, measure the height and volume density of the moraine, and record the basic physical parameters of the moraine for comparative analysis in subsequent shear tests.

[0031] S3. Under different test conditions, use the till direct shear device to conduct shear tests on till specimens; the different test conditions include different ambient temperatures, volumetric rock fragment contents, consolidation pressures, and vertical loads. The method for the till direct shear device to conduct shear tests on till specimens is as follows: Turn on the refrigeration cycle device 11 to make the temperature of the till specimen in the shear box 6 consistent with the preset test temperature; the control device starts the lateral shear force servo loading member 3 and the vertical pressure servo loading member 5; the lateral shear force servo loading member 3 applies a shear load to the till specimen in the shear box 6; the vertical pressure servo loading member 5 applies a vertical load to the till specimen in the shear box 6 until the till specimen fails, completing the shear test.

[0032] Specifically, install the shear box 6 of the consolidated till specimen into the till direct shear device, ensure accurate docking of the shear box 6 with the vertical pressure servo loading member 5 and the lateral shear force servo loading member 3, and maintain stable contact. Turn on the refrigeration cycle device 11, adjust the ambient temperature to the target value T (-10°C, -5°C, 0, 5°C), monitor the internal temperature of the specimen through the temperature sensor 8, and ensure that the temperature fluctuation does not exceed ±0.1°C. Apply a predetermined vertical load N (200 kPa, 400 kPa, 800 kPa), and monitor the change in the vertical displacement V through the laboratory control terminal. After standing for a certain period of time to ensure the stability of the vertical displacement, start the lateral shear force servo loading member 3 to conduct the shear test until the till specimen fails, completing the shear test.

[0033] S4. Obtain the shear stress F and shear displacement S of the till specimen in the shear test, and fit and analyze the till shear characteristics and establish a coupling model based on the shear stress F and shear displacement S; The till shear characteristics include cohesion and internal friction angle; The calculation formula for cohesion is:

[0034] Where, is a constant term representing the basic cohesion; are all fitting coefficients, obtained by experimental regression; T 、 P and V respectively represent the temperature, consolidation pressure, and volumetric rock fragment content of the current till specimen; The calculation formula for the internal friction angle is:

[0035] Where, is a constant term representing the basic internal friction angle; are all fitting coefficients, obtained by experimental regression; T 、 P andV respectively represent the temperature, consolidation pressure, and volumetric rock fragment content of the current moraine specimen; The shear strength of the moraine specimen can be obtained through the cohesion and internal friction angle , specifically, the shear strength of the moraine specimen The calculation formula is:

[0036] where, N is the normal stress.

[0037] Specifically, a multiple non - linear regression model is adopted, and the experimental data is fitted by the least - squares method (OLS) to solve the fitting coefficients of the above - mentioned calculation formula and . The nlinfit function is used for non - linear fitting. Input the test data, including temperature T, consolidation pressure P, rock fragment content V, and the corresponding 𝑐, φ. The model coefficients are calculated iteratively by minimizing the objective function of the fitting error.

[0038] Express the peak shear strength after fitting in a specific form:

[0039]

[0040]

[0041] Combined with the four stages in the direct shear experiment, namely the low - stress region (creep stage), high - stress region (failure point), and shear slip after failure in the transition region, the relationship coefficient between the stress exponent and the friction coefficient is fitted.

[0042] The expression of the coupling model is:

[0043] where, A is the flow factor, which is related to temperature and the microstructure of ice; is the shear stress applied to the moraine specimen; is the shear strength of the moraine specimen; n is the stress exponent; m is an adjustment parameter that controls the transition degree from creep to failure; k is the coefficient related to the friction characteristics of the ice - ice interface or ice - bedrock interface; H is the vertical displacement of the moraine specimen; not explained; is the natural constant, H is the Heaviside function, and its specific condition is that if , its value is 0, if , whose value is 1.

[0044] Stress index n The calculation formula is:

[0045] Where, is the basic stress index, representing the stress index under standard conditions; γ is the consolidation pressure P of the relationship coefficient; δ is the temperature T of the relationship coefficient; T 0 is the reference temperature, referring to the melting temperature of ice; ζ is the relationship coefficient of the volume cuttings content V.

[0046] In this embodiment, the stress index n The specific expression is:

[0047] Coefficient related to the friction characteristics of the ice-ice interface or ice-bedrock interface k The calculation formula is:

[0048] Where, is the basic friction coefficient, representing the friction coefficient under standard conditions; E is the activation energy, representing the influence of temperature change on the friction coefficient; R is the gas constant; is related to the consolidation pressure P of the linear relationship coefficient; β is related to the volume cuttings content V of the linear relationship coefficient, representing the influence of the cuttings volume on the friction coefficient. In this embodiment, the coefficient related to the friction characteristics of the ice-ice interface or ice-bedrock interface k The specific expression is: ; According to the fitting results, analyze the influence of temperature, consolidation pressure and cuttings content on the shear characteristic parameters: as the temperature rises, the cohesion c may decrease, while the internal friction angle increases slightly. Increasing the consolidation pressure P increases the cohesion and internal friction angle. Increasing the cuttings ratio V increases the cohesion, but the influence on the internal friction angle may change non-linearly.

[0049] In summary, a method for analyzing the shear characteristics of moraine considering environmental effects in the present invention comprehensively introduces various environmental factors such as environmental temperature, consolidation pressure, and rock debris content into the analysis. It can accurately reproduce the behavior of moraine under different glacial environmental conditions in the laboratory, quickly measure its physical and mechanical parameters, understand its shear characteristics, and achieve a systematic study of the shear characteristics of moraine under complex environmental conditions, significantly improving the accuracy and reliability of test results. By fitting and analyzing the relationships between the shear parameters of moraine, environmental temperature, rock debris content, and consolidation pressure, the coupling mechanism of environmental effects on shear characteristics is revealed, providing a scientific basis for theoretical research and practical applications.

Claims

1. A method for analyzing the shear characteristics of moraine considering environmental effects, characterized in that, Including the steps: S1. Design and build a direct shear device for moraine considering environmental effects; S2. Use the direct shear device for moraine to prepare moraine specimens; S3. Under different test conditions, use the direct shear device for moraine to conduct shear tests on the moraine specimens; S4. Obtain the shear stress F and shear displacement S of the moraine specimens in the shear test, and fit and analyze the shear characteristics of the moraine and establish a coupling model based on the shear stress F and shear displacement S.

2. The method for analyzing the shear characteristics of moraine considering environmental effects according to claim 1, wherein The direct shear device for moraine considering environmental effects includes a control system, a vertical support frame, and a horizontal support frame; a shear box is arranged on the horizontal support frame, the shear box includes an upper shear box and a lower shear box, one side of the upper shear box is fixedly connected to the horizontal support frame through a horizontal fixing member, and a horizontal shear force servo loading member fixedly connected to the horizontal support frame is arranged on the other side of the lower shear box; a vertical pressure servo loading member is arranged on the vertical support frame directly above the shear box; A wave velocity sensor and a temperature sensor are arranged inside the shear box; a freezing cycle device is arranged outside the shear box; The horizontal shear force servo loading member, the vertical pressure servo loading member, the wave velocity sensor, the temperature sensor, and the freezing cycle device are all electrically connected to the control system.

3. The method for analyzing the shear characteristics of moraine according to claim 2, considering environmental effects, is characterized in that, A support platform is arranged at the bottom of the horizontal support frame, and the shear box is arranged on the upper end surface of the support platform.

4. The method for analyzing the shear characteristics of moraine according to claim 3, considering environmental effects, is characterized in that, The freezing cycle device includes a heat-insulating box sleeved on the outer wall of the shear box, the four side walls of the heat-insulating box are fixedly connected to the vertical support frame and the horizontal support frame through fixing pins, a circulating refrigeration copper pipe is arranged inside the box wall of the heat-insulating box, and the inlet end and the outlet end of the circulating refrigeration copper pipe are both communicated with a compressor located on the outer wall of the heat-insulating box through a liquid guide pipe; the compressor is electrically connected to the control system.

5. The method for analyzing the shear characteristics of moraine according to claim 2, taking into account environmental effects, is characterized in that In step S2, the method for preparing moraine specimens includes the steps: S2.

1. Mix ice chips and rock chips according to the volume rock chip content and fill them into the upper shear box and the lower shear box; S2.

2. Contact the vertical pressure servo loading member with the upper shear box, control the vertical pressure servo loading member to apply a vertical load through the control system, and at the same time turn on the freezing cycle device; S2.

3. Keep the vertical load and temperature constant; measure the test data of vertical displacement and wave velocity in real time until the vertical displacement and wave velocity remain stable and no longer change, then the moraine specimens are consolidated, and the preparation of the moraine specimens is completed.

6. The method for analyzing the shear characteristics of moraine according to claim 2, considering environmental effects, is characterized in that In step S3, different test conditions include different environmental temperatures, volume rock chip contents, consolidation pressures, and vertical loads.

7. The method for predicting the movement distance of dangerous rockfalls under seismic action according to claim 6, wherein In step S3, the method for the direct shear device for moraine to conduct shear tests on the moraine specimens is: turn on the freezing cycle device to make the temperature of the moraine specimens in the shear box consistent with the preset test temperature; control the device to start the horizontal shear force servo loading member and the vertical pressure servo loading member; the horizontal shear force servo loading member applies a shear load to the moraine specimens in the shear box; the vertical pressure servo loading member applies a vertical load to the moraine specimens in the shear box until the moraine specimens are damaged, and the shear test is completed.

8. The method for analyzing the shear characteristics of moraine according to claim 6, considering environmental effects, is characterized in that, In step S4, the shear characteristics of the moraine include cohesion and internal friction angle; The calculation formula for cohesion is as follows: Among them, is a constant term, representing the basic cohesion; are all fitting coefficients, obtained by experimental regression; T , P and V respectively represent the temperature, consolidation pressure and volumetric rock debris content of the current moraine specimen; The calculation formula for the internal friction angle is as follows: Among them, is a constant term, representing the basic internal friction angle; are all fitting coefficients, which are solved by experimental regression; T , P and V respectively represent the temperature, consolidation pressure and volume rock debris content of the current moraine specimen; The expression of the coupling model is: Among them, A is the flow factor, which is related to temperature and the microstructure of ice; is the shear stress applied to the till specimen; is the shear strength of the till specimen; n is the stress exponent; m is an adjustment parameter that controls the transition from creep to failure; k is the coefficient related to the friction characteristics of the ice-ice interface or the ice-bedrock interface; H is the vertical displacement of the till specimen; Not explained; is the natural constant, H is the Heaviside function, and its specific condition is that if , its value is 0, and if , its value is 1; Shear strength of moraine specimens The calculation formula is as follows: Among them, N is the normal stress; Stress index n The calculation formula is as follows: Among them, is the base stress index, representing the stress index under standard conditions; γ is the consolidation pressure P relationship coefficient; δ is the temperature T relationship coefficient; T 0 is the reference temperature, referring to the melting temperature of ice; ζ is the relationship coefficient of the volume cuttings content V; Coefficient related to the friction characteristics of the ice-ice interface or the ice-bedrock interface k The calculation formula is as follows: Among them, is the base friction coefficient, representing the friction coefficient under standard conditions; E is the activation energy, representing the influence of temperature change on the friction coefficient; R is the gas constant; is the linear relationship coefficient with the consolidation pressure P ; β is the linear relationship coefficient with the volume cuttings content V , representing the influence of the cuttings volume on the friction coefficient.

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