Stability assessment method for steeply dipping, layered rock slopes under seismic loading

Abstract

This invention discloses a method for assessing the stability of steeply dipping, internally layered rock slopes under seismic loading, relating to the field of geological safety assessment technology. The method involves acquiring geological parameters of a target geological area, establishing corresponding slope blocks based on these parameters, and fitting the slope blocks to obtain a steeply dipping, internally layered rock model corresponding to the target geological area. Appropriate sensors and DIC speckle patterns are then deployed on the steeply dipping, internally layered rock model to obtain a corresponding physical model of the steeply dipping, internally layered rock slope. This physical model is placed on a shaking table, and a horizontal seismic load is applied to obtain the seismic simulation state parameters of the physical model under the horizontal seismic load. The stability of each slope block within the physical model of the steeply dipping, internally layered rock slope is analyzed based on the obtained seismic simulation state parameters, and the slope stability of the target geological area is determined based on the analysis results.

Description

Technical Field

[0001] This invention relates to the field of geological safety assessment technology, specifically a method for assessing the stability of steeply dipping, layered rock slopes under seismic action. Background Technology

[0002] Earthquake-induced slope instability and landslides pose a serious threat to engineering safety and the safety of people's lives and property in mountainous areas, and are one of the major challenges in the field of geological disaster prevention and control. Among these, steeply sloping, internally layered rock slopes, due to their unique structural characteristics, are extremely prone to instability and failure under seismic dynamics, causing numerous serious disasters such as the Jianshan landslide and the Zhaiziyan landslide. Therefore, conducting accurate assessments of the dynamic stability of steeply sloping, internally layered rock slopes is of great engineering significance.

[0003] How to evaluate the stability of steeply sloping, internally layered rock slopes, thereby providing theoretical support for the precise reinforcement design of slopes, is a problem we need to solve. To this end, we now provide a method for evaluating the stability of steeply sloping, internally layered rock slopes under seismic loading. Summary of the Invention

[0004] The purpose of this invention is to provide a method for assessing the stability of steeply dipping, layered rock slopes under seismic loading.

[0005] The objective of this invention can be achieved through the following technical solution: a method for assessing the stability of steeply dipping, layered rock slopes under seismic loading, comprising:

[0006] Obtain the geological parameters of the target geological area, establish corresponding slope blocks based on the obtained geological parameters of the target geological area, and fit the slope blocks to obtain a steeply dipping inner layered rock model corresponding to the target geological area.

[0007] By deploying corresponding sensors and DIC speckle patterns on the steeply dipping inner-layered rock model, a physical model of the corresponding steeply dipping inner-layered rock slope is obtained.

[0008] The physical model of the steeply dipping inner-layered rock slope was placed on a shaking table and a horizontal seismic load was applied to obtain the seismic simulation state parameters of the physical model of the steeply dipping inner-layered rock slope under the horizontal seismic load.

[0009] The stability of each slope block in the physical model of a steeply dipping, layered rock slope is analyzed based on the obtained seismic simulation state parameters, and the slope stability of the target geological area is judged based on the analysis results.

[0010] Furthermore, the geological parameters include geological structure types, the strike, dip, dip angle, density of each geological structure type, and the relative positional relationship and spacing between different geological structure surfaces;

[0011] Based on the strike, dip, dip angle, and density of the geological parameters corresponding to each geological structure, construct slope blocks corresponding to each geological structure.

[0012] Then, based on the relative positions and spacing between the various geological structures, the corresponding slope blocks are assembled to obtain a steeply sloping inner layered rock model.

[0013] Furthermore, the process of deploying corresponding sensors and DIC speckle patterns on the steeply dipping inner-layered rock model to obtain the corresponding physical model of the steeply dipping inner-layered rock slope includes:

[0014] During the construction of the steeply inclined inner layered rock model, tools were used to excavate spaces for placing sensors at the corresponding positions of each slope block, and the sensors were placed in the corresponding spaces and connected to the signal acquisition instruments.

[0015] After setting DIC speckles on the surface of the steeply dipping inner-layered rock model, the physical model of the steeply dipping inner-layered rock slope is completed.

[0016] Furthermore, the sensors include a triaxial piezoelectric accelerometer, a triaxial capacitive accelerometer, and a laser displacement sensor. The triaxial piezoelectric accelerometer is deployed when the slope is first built, and it is directly connected to the signal acquisition instrument. The triaxial capacitive accelerometer and the laser displacement sensor are first connected to the signal amplifier and then to the signal acquisition instrument.

[0017] Furthermore, the horizontal seismic load A is represented by seismic acceleration.

[0018] Furthermore, the earthquake simulation state parameters include the cohesion of each slope block. Length of sliding surface of slope block Weight of slope blocks internal friction angle The angle between the sliding surface of the slope block and the horizontal plane .

[0019] Furthermore, the process of analyzing the stability of each slope block within the physical model of a steeply dipping, layered rock slope using the obtained seismic simulation state parameters, and determining the slope stability of the target geological area based on the analysis results, includes:

[0020] Based on the obtained seismic simulation state parameters, the rock slope stability coefficient of the physical model of the steeply dipping, inner-layered rock slope is obtained, denoted as Fs, where:

[0021] ;

[0022] in, Let j be the transfer coefficient, representing the friction of another slope block with the i-th slope block. Indicates the anti-slip torque. Indicates the downward torque;

[0023] in, ;

[0024] ;

[0025] ;

[0026] Based on the obtained rock slope stability coefficient Fs, the slope stability of the target geological area is determined, i.e.:

[0027] When Fs=1, it indicates that the slope of the target geological area is in a critical stable state;

[0028] When Fs > 1, it indicates that the slope of the target geological area is in a theoretically stable state;

[0029] When Fs < 1, it indicates that the slope of the target geological area is at risk of instability.

[0030] Furthermore, the process of obtaining the horizontal seismic inertial force at different elevation locations in a target geological area at risk of instability is as follows:

[0031] Obtain the elevation of each slope block, and record the elevation of the slope block labeled i as . ;

[0032] The dynamic distribution coefficient of the elevation influence of each slope block is then obtained, denoted as . ,in:

[0033] ;

[0034] in, H represents the basic coefficient of the slope block, and H represents the slope height of the physical model of the steeply sloping inner layered rock slope.

[0035] Based on the obtained dynamic distribution coefficient of elevation influence, the dynamic distribution coefficient of elevation-slope gradient influence is obtained, denoted as [missing information]. ,in:

[0036] ;

[0037] in, This refers to the slope gradient corresponding to the location of the slope block;

[0038] This allows us to obtain the horizontal seismic inertial force at each location, denoted as... ,in:

[0039] ;

[0040] in, This represents the base seismic acceleration at the corresponding location. This is the reduction factor for the effect of seismic action, usually taken as 0.25.

[0041] Compared with the prior art, the beneficial effects of the present invention are:

[0042] 1. Based on the failure mode of the shaking table test model and the seismic simulation state parameters of the physical model of the steeply dipping inner layered rock slope under horizontal seismic load, the stability of the non-uniform distribution of acceleration space is analyzed, so that the calculation results can more realistically reflect the actual instability process of the slope.

[0043] 2. An improvement scheme is proposed to address the limitations of the traditional quasi-static method. This involves reconstructing the seismic inertial force calculation formula by introducing a modified dynamic distribution coefficient and incorporating the elevation amplification effect. With respect to the effect of slope The calculation model takes into account the influence of slope and elevation on the acceleration amplification effect, so that the stability calculation results considering the non-uniform distribution of acceleration space can more realistically reflect the actual instability process of the slope. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0045] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0046] like Figure 1 As shown, a method for assessing the stability of steeply dipping, internally layered rock slopes under seismic loading includes:

[0047] Obtain the geological parameters of the target geological area, establish corresponding slope blocks based on the obtained geological parameters of the target geological area, and fit the slope blocks to obtain a steeply dipping inner layered rock model corresponding to the target geological area.

[0048] By deploying corresponding sensors and DIC speckle patterns on the steeply dipping inner-layered rock model, a physical model of the corresponding steeply dipping inner-layered rock slope is obtained.

[0049] The physical model of the steeply dipping inner-layered rock slope was placed on a shaking table and a horizontal seismic load was applied to obtain the seismic simulation state parameters of the physical model of the steeply dipping inner-layered rock slope under the horizontal seismic load.

[0050] The stability of each slope block in the physical model of a steeply dipping, layered rock slope is analyzed based on the obtained seismic simulation state parameters, and the slope stability of the target geological area is judged based on the analysis results.

[0051] Obtain the horizontal seismic inertial force at different elevation locations in the target geological area where instability risk exists.

[0052] It should be further explained that, in the specific implementation process, the process of obtaining geological parameters of the target geological area, establishing corresponding slope blocks based on the obtained geological parameters, and fitting the slope blocks to obtain a steeply dipping inner-layered rock model corresponding to the target geological area includes:

[0053] Geological exploration of a target geological area is conducted using ground-penetrating radar to obtain the geological structure of the target geological area and the corresponding geological parameters. It should be noted that in practical applications, the method of obtaining the geological structure of the target geological area needs to be adjusted by technicians according to the actual situation. In addition to ground-penetrating radar, the methods used also include electrical exploration, geological sampling, seismic waves, etc.

[0054] The geological parameters include geological structure types, the strike, dip, dip angle, density of each geological structure type, the relative positional relationship and spacing between different geological structure surfaces, etc.

[0055] Based on the strike, dip, dip angle, and density of the geological parameters corresponding to each geological structure, construct slope blocks corresponding to each geological structure. It should be noted that the slope blocks are constructed by technicians according to the conditions of the target geological area and in a certain proportion. The construction method can be manual or, if conditions permit, 3D printing can be used.

[0056] Then, based on the relative positions and spacing between the various geological structures, the corresponding slope blocks are assembled to obtain a steeply sloping inner-layered rock model. It should be noted that when assembling the slope blocks, the assembly begins from the toe of the slope and proceeds layer by layer.

[0057] It should be further explained that, in the specific implementation process, the process of deploying corresponding sensors and DIC speckle patterns on the steeply dipping inner-layered rock model to obtain the corresponding physical model of the steeply dipping inner-layered rock slope includes:

[0058] During the construction of the steeply sloping inner-layered rock model, tools were used to excavate spaces for placing sensors at corresponding locations on each slope block. The sensors were then placed in their respective spaces and connected to the signal acquisition instrument. The sensors included a triaxial piezoelectric accelerometer, a triaxial capacitive accelerometer, and a laser displacement sensor. The triaxial piezoelectric accelerometer was deployed at the beginning of the construction at the slope toe and was directly connected to the signal acquisition instrument. The triaxial capacitive accelerometer and the laser displacement sensor were first connected to the signal amplifier before being connected to the signal acquisition instrument.

[0059] After setting DIC speckles on the surface of the steeply dipping inner-layered rock model, the physical model of the steeply dipping inner-layered rock slope is completed.

[0060] It should be further explained that, in the specific implementation process, the process of placing the physical model of the steeply dipping, internally layered rock slope on a shaking table and applying a horizontal seismic load to obtain the seismic simulation state parameters of the physical model of the steeply dipping, internally layered rock slope under the horizontal seismic load includes:

[0061] The horizontal seismic load includes natural waves and artificial waves. Natural waves include El-Centro waves, Wenchuan Wolong waves, and Mianzhu Qingping waves. Artificial waves include Ricker waves and sine waves (i.e., white noise with a fixed amplitude). It should be noted that the magnitude of the seismic wave input in the experiment is controlled by the acceleration amplitude. Various seismic waves are loaded starting from 0.1g, increasing by 0.1g at each level until reaching 0.3g. The dynamic response of the slope is studied under as many conditions as possible during low-amplitude loading. After 0.3g, to study the deformation and failure process of the model, 10Hz, 50Hz sine waves, and MZQP-5T seismic waves are gradually increased in increments of 0.1g until the model is completely destroyed. Other seismic wave input schemes can be used in practical applications, which are not listed here.

[0062] Each slope block is numbered sequentially from bottom to top and denoted as i, where i = 1, 2, ..., n;

[0063] The applied horizontal seismic load is denoted as A and represented by seismic acceleration;

[0064] The earthquake simulation state parameters include the cohesion of each slope block, the length of the sliding surface of the slope block, the weight of the slope block, the internal friction angle, and the angle between the sliding surface of the slope block and the horizontal plane.

[0065] The cohesion, sliding surface length, weight, internal friction angle, and angle between the sliding surface of the slope block (labeled i) and the horizontal plane are respectively marked as follows: , , , , .

[0066] It should be further explained that, in the specific implementation process, the process of analyzing the stability of each slope block within the physical model of the steeply dipping, layered rock slope using the obtained seismic simulation state parameters, and judging the slope stability of the target geological area based on the analysis results, includes:

[0067] Based on the obtained seismic simulation state parameters, the rock slope stability coefficient of the physical model of the steeply dipping, inner-layered rock slope is obtained, denoted as Fs, where:

[0068] ;

[0069] in, Let j be the transfer coefficient, representing the friction of another slope block with the i-th slope block. Indicates the anti-slip torque. Indicates the downward torque;

[0070] in, ;

[0071] ;

[0072] ;

[0073] Based on the obtained rock slope stability coefficient Fs, the slope stability of the target geological area is determined, i.e.:

[0074] When Fs=1, it indicates that the slope of the target geological area is in a critical stable state;

[0075] When Fs > 1, it indicates that the slope of the target geological area is in a theoretically stable state;

[0076] When Fs < 1, it indicates that the slope of the target geological area is at risk of instability.

[0077] It should be further explained that, in the specific implementation process, the process of obtaining the horizontal seismic inertial force at different elevation locations in the target geological area with instability risk is as follows:

[0078] Obtain the elevation of each slope block, and record the elevation of the slope block labeled i as . ;

[0079] The dynamic distribution coefficient of the elevation influence of each slope block is then obtained, denoted as . ,in:

[0080] ;

[0081] in, This represents the foundation coefficient for the slope masonry blocks. The slope height is the physical model of a steeply sloping, inner-layered rock slope.

[0082] Based on the obtained dynamic distribution coefficient of elevation influence, the dynamic distribution coefficient of elevation-slope gradient influence is obtained, denoted as [missing information]. ,in:

[0083] ;

[0084] in, This refers to the slope gradient corresponding to the location of the slope block;

[0085] This allows us to obtain the horizontal seismic inertial force at each location, denoted as... ,in:

[0086] ;

[0087] in, This represents the base seismic acceleration at the corresponding location. This is the reduction factor for the effect of seismic action, usually taken as 0.25.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any modifications or equivalent substitutions made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for stability evaluation of steeply inclined inner-layered rock slope under seismic action, characterized in that, The method comprises the following steps: obtaining geological parameters of a target geological region, establishing corresponding slope body blocks according to the obtained geological parameters of the target geological region, and fitting the slope body blocks to obtain an abrupt-inclined internal layer rock model corresponding to the target geological region; arranging corresponding sensors and DIC speckles on the abrupt-inclined internal layer rock model to obtain a corresponding abrupt-inclined internal layer rock slope physical model; placing the abrupt-inclined internal layer rock slope physical model on a shaking table and applying a horizontal seismic load to obtain seismic simulation state parameters of the abrupt-inclined internal layer rock slope physical model under the horizontal seismic load; analyzing the stability of each slope body block in the abrupt-inclined internal layer rock slope physical model according to the obtained seismic simulation state parameters, and judging the slope stability of the target geological region according to the analysis result; the geological parameters include geological structure types, strike, trend, dip angle, density of each geological structure type, relative position relationship and spacing between different geological structure surfaces; according to the strike, trend, dip angle and density in the geological parameters corresponding to each geological structure, slope body blocks corresponding to each geological structure are built; according to the relative position relationship and spacing between each geological structure, the corresponding slope body blocks are built to obtain the abrupt-inclined internal layer rock model; The seismic simulation state parameters include cohesion of each slope block , sliding surface length of the slope block , weight of the slope block , internal friction angle , angle between the sliding surface part of the slope block and the horizontal plane ; the process of analyzing the stability of each slope body block in the abrupt-inclined internal layer rock slope physical model according to the obtained seismic simulation state parameters and judging the slope stability of the target geological region according to the analysis result comprises: obtaining a rock slope stability coefficient of the abrupt-inclined internal layer rock slope physical model according to the obtained seismic simulation state parameters, denoted as Fs, wherein: ； wherein, is the transmission coefficient, j denotes another slope block in friction with the i-th slope block, denotes the anti-sliding moment, denotes the sliding-down moment; wherein ; ； ； judging the slope stability of the target geological region according to the obtained rock slope stability coefficient Fs, that is: when Fs=1, it indicates that the slope of the target geological region is in a critical stable state; when Fs>1, it indicates that the slope of the target geological region is in a theoretically stable state; when Fs<1, it indicates that the slope of the target geological region has a risk of instability.

2. The method for stability evaluation of steeply dipping inner stratified rock mass slope under seismic action according to claim 1, characterized in that, the process of arranging corresponding sensors and DIC speckles on the abrupt-inclined internal layer rock model to obtain a corresponding abrupt-inclined internal layer rock slope physical model comprises: during the process of building the abrupt-inclined internal layer rock model, a tool is used to excavate a space for placing a sensor at a corresponding position of each slope body block, and the sensor is placed in the corresponding space, and each sensor is connected with a signal acquisition instrument; after setting the DIC speckles on the surface of the abrupt-inclined internal layer rock model, the building of the abrupt-inclined internal layer rock slope physical model is completed, and each slope body block is sequentially labeled from bottom to top, denoted as i, wherein i=1, 2, …, n.

3. The method for stability evaluation of steeply dipping inner stratified rock mass slope under seismic action according to claim 2, characterized in that, the sensors include three-way piezoelectric acceleration sensors, three-way capacitive acceleration sensors and laser displacement sensors, the three-way piezoelectric acceleration sensors are arranged at the beginning of building the slope foot, and the three-way piezoelectric sensors are directly connected with the signal acquisition instrument, while the three-way capacitive acceleration sensors and the laser displacement sensors are first connected with a signal amplifier and then connected to the signal acquisition instrument.

4. The method for stability evaluation of steeply dipping inner stratified rock mass slope under seismic action according to claim 1, characterized in that, the horizontal seismic load A is embodied by a seismic acceleration.

5. The method for stability evaluation of steeply dipping inner stratified rock mass slope under seismic action according to claim 4, characterized in that The process for obtaining horizontal seismic inertial forces at different elevation locations of a target geologic region at risk of instability is: obtaining the elevation of each slope block, and recording the elevation of the slope block labeled i as hi ; then the elevation influence dynamic distribution coefficient of each slope body block is obtained ; Based on the obtained elevation influence dynamic distribution coefficient, an elevation-slope gradient influence dynamic distribution coefficient is obtained, denoted as wherein: ； wherein, is the slope gradient corresponding to the position of the slope block; Further, the horizontal seismic inertial force at each position is obtained, denoted as wherein: ； wherein, is the base ground acceleration at the corresponding location, is the effect reduction factor for the seismic action.

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