Evaluation model construction, stability evaluation method and system of soft-hard interbedded slope

Abstract

This invention discloses an evaluation model construction, stability evaluation method, and system for a dip-slope with alternating soft and hard joints. The process includes: first, collecting test data from multiple sets of rock joint shear tests (both soft and hard joints); then, using all the collected test data, fitting coefficients are obtained in a joint shear strength prediction model, and a joint shear strength prediction model based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, and the normal stress is constructed using these fitting coefficients; subsequently, based on the joint shear strength prediction model and combined with a simplified slope mechanics model, a safety factor evaluation model based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding plane dip angle, the bedding plane thickness, and the rock mass unit weight is derived. This constructs a safety factor evaluation model that considers both the joint surface morphology characteristics and the strength differences between the upper and lower walls of the dip-slope with alternating soft and hard joints.

Description

Technical Field

[0001] This invention relates to the fields of design optimization, verification, or simulation technology, and specifically to the construction of an evaluation model, a stability evaluation method, and a system for a soft-hard interlayered dip slope. Background Technology

[0002] Layered rock masses, widely distributed in nature, are an important component of the lithosphere. Among them, interbedded soft and hard rock masses are a common geological structure in layered dip slopes. Their instability can easily lead to significant economic losses and casualties, highlighting prominent engineering stability issues. Unlike conventional rock masses with uniform properties at their joint surfaces, soft and hard joints exhibit significant differences in mechanical behavior. Existing slope stability analysis methods fail to fully consider the influence of the strength difference between the upper and lower walls at the interface of interbedded soft and hard joints, resulting in inaccurate and unrealistic assessments of their stability. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention proposes an evaluation model construction, stability evaluation method, and system for dip-slopes with alternating soft and hard layers, which can improve the accuracy and engineering applicability of stability evaluation for dip-slopes with alternating soft and hard layers. The specific technical solution is as follows: In a first aspect, a method for constructing an evaluation model for a soft-hard interlayered slope with a dip-sloping profile is provided. In a first implementable method of this first aspect, the method includes: Obtain experimental data from multiple sets of rock soft and hard joint shear tests; Based on all the experimental data obtained, a joint shear strength prediction model was constructed based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, and the normal stress. Based on the joint shear strength prediction model, and combined with the simplified slope mechanics model, a safety factor evaluation model is constructed based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding plane dip angle, the bedding plane thickness, and the rock mass unit weight.

[0004] In conjunction with the first feasible method of the first aspect, in the second feasible method of the first aspect, the joint shear strength prediction model is constructed, including: The joint shear strength prediction model was constructed based on the Barton formula.

[0005] In conjunction with the first possible implementation of the first aspect, in the third possible implementation of the first aspect, the safety factor evaluation model is constructed, including: By combining the joint shear strength prediction model, the normal stress model acting on the surface of the sliding fault and the gravity model of the sliding fault in the simplified slope mechanics model, a resistance model of the sliding fault is constructed. The safety factor evaluation model is constructed by integrating the resistance model and the sliding force model of the slip fault.

[0006] Secondly, a stability evaluation method for alternating soft and hard layers along a dip slope is provided. In the first feasible implementation of this second aspect, it includes: An evaluation model for the safety factor of a soft-hard interlayered slope is constructed by adopting any of the first to third feasible methods described in the first aspect. Obtain the basic friction angle, average shear undulation angle, joint strength ratio, bedding plane dip angle, bedding plane thickness, and rock mass unit weight of the joint surface of the soft-hard interbedded dip slope; Based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding angle, the bedding thickness, and the unit weight of the rock mass, the safety factor of the soft and hard interbedded dip slope is calculated using a safety factor evaluation model.

[0007] In conjunction with the first possible implementation of the second aspect, in the second possible implementation of the second aspect, obtaining the basic friction angle of the joint surface includes: Planar joint surfaces were prepared by sampling from the alternating soft and hard slope, and the basic friction angle of the joint surfaces was determined by shearing tests.

[0008] In conjunction with the first possible implementation of the second aspect, in the third possible implementation of the second aspect, obtaining the shear average fluctuation angle includes: The three-dimensional point cloud data of the joint surface of the soft and hard interlayered dip slope is obtained, and the average shear undulation angle is calculated based on the three-dimensional point cloud data of the joint surface.

[0009] In conjunction with the first possible implementation of the second aspect, in the fourth possible implementation of the second aspect, obtaining the joint strength ratio includes: Samples were taken from the dip-slope with alternating soft and hard layers, and uniaxial tests were conducted on the extracted samples to obtain the joint wall compressive strength of the soft and hard rocks in the dip-slope with alternating soft and hard layers. The joint strength ratio is calculated based on the maximum and minimum values ​​of the joint wall compressive strength.

[0010] Thirdly, a safety factor evaluation model construction system for alternating soft and hard slopes with a dip-sloping profile is provided, including: The test data module is configured to acquire test data from multiple sets of rock soft and hard joint shear tests; The prediction model module is configured to construct a joint shear strength prediction model based on the basic friction angle of the joint surface, the average shear fluctuation angle, the joint strength ratio, and the normal stress using all the acquired experimental data. The evaluation model module is configured to construct a safety factor evaluation model based on the joint shear strength prediction model and combined with the simplified slope mechanics model, using the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the dip angle of the bedding plane, the bedding plane thickness, and the unit weight of the rock mass.

[0011] Fourthly, a stability evaluation system for alternating soft and hard slopes with a dip-sloping profile is provided, including: The model building module is configured to use the evaluation model building method described in any of the first to third implementable methods of the first aspect to build a safety factor evaluation model for a soft and hard interlayered slope; The data acquisition module is configured to acquire the basic friction angle of joint surfaces, average shear undulation angle, joint strength ratio, bedding plane dip angle, bedding plane thickness, and rock mass unit weight of interbedded soft and hard slopes. The coefficient evaluation module is configured to calculate the safety factor of a soft-hard interbedded dip slope based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding angle, the bedding thickness, and the rock mass unit weight, using a safety factor evaluation model.

[0012] Beneficial effects: The evaluation model, stability evaluation method and system for interlayered soft and hard slopes of the present invention can construct a safety factor evaluation model that takes into account the joint surface morphology characteristics and the strength difference between the upper and lower walls of the interlayered soft and hard slope. By evaluating the safety factor of the interlayered soft and hard slope through this safety factor evaluation model, the accuracy and engineering applicability of the stability evaluation of the interlayered soft and hard slope can be significantly improved. Attached Figure Description

[0013] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0014] Figure 1 A flowchart illustrating a method for constructing an evaluation model for a soft-hard interlayered slope according to an embodiment of the present invention; Figure 2 A flowchart illustrating a method for evaluating the stability of a slope with alternating layers of soft and hard rock, according to an embodiment of the present invention; Figure 3 A system block diagram of an evaluation model construction system for a soft-hard interlayered dip slope provided in an embodiment of the present invention; Figure 4 This is a system block diagram of a stability evaluation system for a soft-hard interlayered slope with a dip-sloping profile, provided in an embodiment of the present invention. Figure 5 The results are from multiple sets of rock soft and hard joint shear tests; Figure 6 This is a simplified mechanical model diagram of a slope with alternating layers of soft and hard materials. Detailed Implementation

[0015] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0016] like Figure 1 The flowchart shown illustrates the method for constructing an evaluation model for a slope with alternating layers of soft and hard materials. This method includes: Step 1: Obtain test data from multiple sets of rock soft and hard joint shear tests; Step 2: Based on all the obtained experimental data, construct a joint shear strength prediction model based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, and the normal stress. Step 3: Based on the joint shear strength prediction model and combined with the simplified slope mechanics model, construct a safety factor evaluation model based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the dip angle of the bedding plane, the bedding plane thickness, and the unit weight of the rock mass.

[0017] Specifically, firstly, multiple sets of test data from rock soft and hard joint shear tests can be collected. The collected test data are as follows: Figure 5 As shown. Then, by fitting all the collected experimental data, the fitting coefficients in the joint shear strength prediction model can be obtained, and a joint shear strength prediction model based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, and the normal stress can be constructed using the fitting coefficients. Subsequently, based on the joint shear strength prediction model and combined with the designed simplified slope mechanics model, a safety factor evaluation model based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding plane dip angle, the bedding plane thickness, and the rock mass unit weight can be derived. Thus, a safety factor evaluation model that takes into account the joint surface morphology characteristics and the strength difference between the upper and lower walls of the soft and hard interlayered dip-slope can be constructed. Evaluating the safety factor of the soft and hard interlayered dip-slope using this safety factor evaluation model can significantly improve the accuracy and engineering applicability of the stability evaluation of the soft and hard interlayered dip-slope.

[0018] In this embodiment, optionally, the joint shear strength prediction model is constructed, including: The joint shear strength prediction model was constructed based on the Barton formula.

[0019] Specifically, based on Barton's formula, and combined with the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, and the normal stress, a joint shear strength prediction model can be constructed. The specific calculation formula is as follows: ; in, For joint shear strength, This refers to the normal stress acting on the surface of a sliding fault in a dip-slope with alternating layers of hard and soft rock. The basic friction angle of the joint surface of a slope with alternating layers of hard and soft materials. The shear mean undulation angle is the slope with alternating layers of soft and hard materials dipping downwards. These are the fitting coefficients. This is the joint strength ratio.

[0020] In this embodiment, optionally, constructing the safety factor evaluation model includes: By combining the joint shear strength prediction model with the normal stress model acting on the surface of the sliding fault and the gravity model of the sliding fault in the simplified slope mechanics model, a resistance model of the sliding fault is constructed. A safety factor evaluation model is constructed by integrating the resistance model and the sliding force model of the slip fault.

[0021] Specifically, a resistance model for sliding faults in interbedded soft and hard slopes can be constructed by combining a joint shear strength prediction model with a simplified slope mechanics model. For example... Figure 6 As shown, the simplified slope mechanics model includes a model for calculating the normal stress acting on the surface of the sliding fault, and a gravity model for calculating the gravity of the sliding fault. The normal stress model is specifically as follows: ; The gravity model is as follows: ; in, For the gravity of the sliding fault, The dip angle of the sliding fault. The length of the slip fault. The thickness of the slip fault plane. This is the unit weight of the rock mass.

[0022] The resistance model constructed by combining the joint shear strength prediction model and the simplified slope mechanics model is as follows: ; The specific calculation formula for the subsidence force model of a slip fault is as follows: .

[0023] The safety factor evaluation model constructed based on the resistance model and the sliding force model of the slip fault is as follows: .

[0024] The final safety factor evaluation model takes into account the joint surface morphology characteristics of alternating hard and soft slopes, such as the average shear undulation angle, as well as the strength difference between the upper and lower walls, such as the joint strength ratio. Using this safety factor evaluation model to assess the safety factor of alternating hard and soft slopes can significantly improve the accuracy and engineering applicability of stability evaluation for such slopes.

[0025] like Figure 2 The flowchart shown illustrates a stability evaluation method for a slope with alternating layers of soft and hard rock, which includes: Step S1: Using the above-mentioned evaluation model construction method, a safety factor evaluation model for a soft-hard interlayered slope with a dip-sloping profile is constructed. Step S2: Obtain the basic friction angle, average shear undulation angle, joint strength ratio, bedding plane dip angle, bedding plane thickness, and rock mass unit weight of the joint surface of the soft and hard interbedded slope. Step S3: Calculate the safety factor of the soft-hard interbedded dip slope based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding angle, the bedding thickness, and the rock mass unit weight using the safety factor evaluation model.

[0026] Specifically, firstly, the aforementioned evaluation model construction method can be used to construct a safety factor evaluation model that considers both the joint surface morphology characteristics and the strength differences between the upper and lower walls of a dip-slope with alternating hard and soft layers. Then, through sampling tests and field measurements, the basic friction angle, shear mean undulation angle, joint strength ratio, bedding plane dip angle, bedding plane thickness, and rock mass unit weight of the dip-slope with alternating hard and soft layers can be obtained. Finally, based on the obtained basic friction angle, shear mean undulation angle, joint strength ratio, bedding plane dip angle, bedding plane thickness, and rock mass unit weight, the safety factor of the dip-slope with alternating hard and soft layers can be calculated using the constructed safety factor evaluation model. By simultaneously considering the joint surface morphology characteristics and the strength differences between the upper and lower walls, the accuracy and engineering applicability of the evaluation can be significantly improved.

[0027] In this embodiment, optionally, obtaining the basic friction angle of the joint surface includes: Planar joint surfaces were prepared by sampling from the alternating soft and hard slope, and the basic friction angle of the joint surfaces was determined by shearing tests.

[0028] Specifically, on-site sampling can be conducted at the dip-slope of alternating soft and hard rock layers, and planar joint surfaces can be prepared based on the obtained soft and hard rock samples. Shear tests are then performed on the planar joint surfaces, applying external loads in the low normal and tangential directions, and the basic friction angle of the joint surfaces of the dip-slope of alternating soft and hard rock layers can be determined through experimental data.

[0029] In this embodiment, optionally, obtaining the shear average fluctuation angle includes: The three-dimensional point cloud data of the joint surface of the soft and hard interlayered dip slope is obtained, and the average shear undulation angle is calculated based on the three-dimensional point cloud data of the joint surface.

[0030] Specifically, firstly, a 3D LiDAR scan of a dip-slope with alternating hard and soft layers can be used to obtain 3D point cloud data of the joint surfaces. Then, the 3D point cloud data of the joint surfaces is imported into MATLAB software, which is used to calculate the actual area and projected area of ​​the joint surfaces. Finally, the average shear undulation angle can be calculated based on the actual area and projected area of ​​the joint surfaces, using the following formula: ; in, For the projected area, This represents the actual area.

[0031] In this embodiment, optionally, obtaining the joint strength ratio includes: Samples were taken from the dip-slope with alternating soft and hard layers, and uniaxial tests were conducted on the extracted samples to obtain the joint wall compressive strength of the soft and hard rocks in the dip-slope with alternating soft and hard layers. The joint strength ratio is calculated based on the maximum and minimum values ​​of the joint wall compressive strength.

[0032] Specifically, on-site sampling can be conducted on a dip-slope with alternating soft and hard rock layers. Using these samples, corresponding specimens are prepared for uniaxial tests to obtain the compressive strength of the joint walls between the soft and hard rock layers. This compressive strength includes the compressive strength of the joint wall with the higher compressive strength. and the compressive strength of joint walls with low compressive strength By combining the two, the joint strength ratio can be calculated. The specific calculation formula is as follows: .

[0033] For bedding thickness, existing measuring instruments, such as total stations or GPS, can be used to measure the bedding thickness of a dip-slope with alternating hard and soft bedding. For rock mass unit weight, the bedding angle and rock mass unit weight can be obtained by consulting geological data of the dip-slope with alternating hard and soft bedding or by conducting on-site investigations.

[0034] After obtaining the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding angle, the bedding thickness, and the unit weight of the rock mass corresponding to the soft and hard interbedded dip slope, these parameters can be substituted into the safety factor evaluation model to calculate the safety factor of the soft and hard interbedded dip slope.

[0035] To verify the effectiveness of the evaluation method provided in this embodiment, multiple sets of different test parameters were obtained through repeated experiments. Based on the obtained test parameters, the safety factor of the soft and hard interlayered slope with dip-sloping sides under different parameters was calculated using the evaluation method provided in this embodiment. The calculation results are shown in the table below: like Figure 3 The diagram shown is a system block diagram of a safety factor evaluation model construction system for alternating soft and hard slopes. This system includes: The test data module is configured to acquire test data from multiple sets of rock soft and hard joint shear tests; The prediction model module is configured to construct a joint shear strength prediction model based on the basic friction angle of the joint surface, the average shear fluctuation angle, the joint strength ratio, and the normal stress using all the acquired experimental data. The evaluation model module is configured to construct a safety factor evaluation model based on the joint shear strength prediction model and combined with the simplified slope mechanics model, using the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the dip angle of the bedding plane, the bedding plane thickness, and the unit weight of the rock mass.

[0036] Specifically, the system comprises an experimental data module, a prediction model module, and an evaluation model module. The experimental data module acquires experimental data from multiple sets of rock joint shear tests (both soft and hard). The prediction module uses all collected experimental data to fit the fitting coefficients in the joint shear strength prediction model, and then constructs a joint shear strength prediction model based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, and the normal stress. The evaluation model module, based on the joint shear strength prediction model and combined with a simplified slope mechanics model, derives a safety factor evaluation model based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding plane dip angle, the bedding plane thickness, and the rock mass unit weight.

[0037] like Figure 4 The diagram shown illustrates the system block diagram of a stability evaluation system for a slope with alternating layers of soft and hard rock. This evaluation system includes: The model building module is configured to use the above-mentioned evaluation model building method to build a safety factor evaluation model for soft and hard interlayered dip slopes; The data acquisition module is configured to acquire the basic friction angle of joint surfaces, average shear undulation angle, joint strength ratio, bedding plane dip angle, bedding plane thickness, and rock mass unit weight of interbedded soft and hard slopes. The coefficient evaluation module is configured to calculate the safety factor of a soft-hard interbedded dip slope based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding angle, the bedding thickness, and the rock mass unit weight, using a safety factor evaluation model.

[0038] Specifically, the evaluation system includes a model building module, a data acquisition module, and a coefficient evaluation module. The model building module constructs a safety factor evaluation model using the aforementioned evaluation model construction methods. The data acquisition module obtains the basic friction angle, shear mean undulation angle, joint strength ratio, bedding plane dip angle, bedding plane thickness, and rock mass unit weight of the interbedded soft and hard slope through sampling tests, field measurements, and other methods. The coefficient evaluation module calculates the safety factor of the interbedded soft and hard slope based on the obtained basic friction angle, shear mean undulation angle, joint strength ratio, bedding plane dip angle, bedding plane thickness, and rock mass unit weight using the constructed safety factor evaluation model. By simultaneously considering the joint surface morphology and the strength difference between the upper and lower walls, the accuracy and engineering applicability of the evaluation can be significantly improved.

[0039] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for constructing an evaluation model for a slope with alternating layers of soft and hard slopes, characterized in that, include: Obtain experimental data from multiple sets of rock soft and hard joint shear tests; Based on all the experimental data obtained, a joint shear strength prediction model was constructed based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, and the normal stress. Based on the joint shear strength prediction model, and combined with the simplified slope mechanics model, a safety factor evaluation model is constructed based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding plane dip angle, the bedding plane thickness, and the rock mass unit weight.

2. The evaluation model construction method according to claim 1, characterized in that, The joint shear strength prediction model is constructed as follows: The joint shear strength prediction model was constructed based on the Barton formula.

3. The evaluation model construction method according to claim 1, characterized in that, Constructing the safety factor evaluation model includes: By combining the joint shear strength prediction model, the normal stress model acting on the surface of the sliding fault and the gravity model of the sliding fault in the simplified slope mechanics model, a resistance model of the sliding fault is constructed. The safety factor evaluation model is constructed by integrating the resistance model and the sliding force model of the slip fault.

4. A method for evaluating the stability of a slope with alternating layers of soft and hard rock, characterized in that, include: Using the evaluation model construction method described in any one of claims 1-3, a safety factor evaluation model for a soft-hard interlayered slope with a dip-sloping profile is constructed. Obtain the basic friction angle, average shear undulation angle, joint strength ratio, bedding plane dip angle, bedding plane thickness, and rock mass unit weight of the joint surface of the soft-hard interbedded dip slope; Based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding angle, the bedding thickness, and the unit weight of the rock mass, the safety factor of the soft and hard interbedded dip slope is calculated using a safety factor evaluation model.

5. The stability evaluation method according to claim 4, characterized in that, Obtaining the basic friction angle of the joint surface includes: Planar joint surfaces were prepared by sampling from the alternating soft and hard slope, and the basic friction angle of the joint surfaces was determined by shearing tests.

6. The stability evaluation method according to claim 4, characterized in that, Obtaining the shear average fluctuation angle includes: The three-dimensional point cloud data of the joint surface of the soft and hard interlayered dip slope is obtained, and the average shear undulation angle is calculated based on the three-dimensional point cloud data of the joint surface.

7. The stability evaluation method according to claim 4, characterized in that, Obtaining the joint strength ratio includes: Samples were taken from the dip-slope with alternating soft and hard layers, and uniaxial tests were conducted on the extracted samples to obtain the joint wall compressive strength of the soft and hard rocks in the dip-slope with alternating soft and hard layers. The joint strength ratio is calculated based on the maximum and minimum values ​​of the joint wall compressive strength.

8. A system for constructing a safety factor evaluation model for alternating soft and hard slopes, characterized in that, include: The test data module is configured to acquire test data from multiple sets of rock soft and hard joint shear tests; The prediction model module is configured to construct a joint shear strength prediction model based on the basic friction angle of the joint surface, the average shear fluctuation angle, the joint strength ratio, and the normal stress using all the acquired experimental data. The evaluation model module is configured to construct a safety factor evaluation model based on the joint shear strength prediction model and combined with the simplified slope mechanics model, using the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the dip angle of the bedding plane, the bedding plane thickness, and the unit weight of the rock mass.

9. A stability evaluation system for a slope with alternating layers of soft and hard rock, characterized in that, include: The model building module is configured to use the evaluation model building method as described in any one of claims 1-3 to build a safety factor evaluation model for a soft-hard interlayered slope with a dip-sloping profile. The data acquisition module is configured to acquire the basic friction angle of joint surfaces, average shear undulation angle, joint strength ratio, bedding plane dip angle, bedding plane thickness, and rock mass unit weight of interbedded soft and hard slopes. The coefficient evaluation module is configured to calculate the safety factor of a soft-hard interbedded dip slope based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding angle, the bedding thickness, and the rock mass unit weight, using a safety factor evaluation model.

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