Test method and system for rock mass stability analysis

Abstract

A test method and system for rock mass stability analysis. The test method includes: obtaining bare structural surface image information and internal structural surface radar information of rock mass; constructing a structural surface spatial information probability model of rock mass based on the bare structural surface image information and the internal structural surface radar information; manufacturing a rock mass physics large-scale model based on the structural surface spatial information probability model; obtaining on-site feedback information of rock mass at the disturbance of the mining site; determining a test pressure for the rock mass physics large-scale model based on the on-site feedback information; testing the rock mass physics large-scale model based on the test pressure, and simulating the stability change of rock mass by comprehensively considering the action influence of the disturbance of mining, high seepage pressure and discontinuous structural surface; obtaining the test feedback information of the rock mass physics large-scale model at the test pressure. The present application constructs a rock mass model that matches the actual situation of the surrounding rocks at the site, and responds realistically to the stability situation of the surrounding rocks at the site, thereby providing security for coal mining.

Description

[Technical field]

[0001] The present application relates to the technical field of rock mass stability analysis, and in particular to a testing method and system for rock mass stability analysis. [Background technology]

[0002] During the deep mining process of coal mines, rock masses are subject to mining disturbance, high seepage pressure and discontinuous structural surfaces, which makes them highly susceptible to widespread collapse of surrounding rocks and flooding and other disasters. This makes the stability control problem of deep rock masses increasingly prominent, posing a major threat to the safe mining of coal.

[0003] Only by taking into consideration the stability of the surrounding rocks caused by mining disturbance, high seepage pressure, deep rock masses and discontinuous structural surfaces, etc., can the stability of deep rock masses be fundamentally controlled. At the same time, the research object of the stability of the rocks around coal mines is often rock specimens, but the research of rock specimens is insufficient to reflect the stability situation of the surrounding rocks at the construction scale.

[0004] Based on this, some researchers have begun to use large-scale models to experimentally analyze the deformation and bursting rules of the surrounding rocks. However, the rock masses in large-scale model tests are often constructed as layered models, while ignoring the influence of the internal structure of the rock mass on the rock mass. As a result, the manufactured models are insufficient to reflect the structural distribution characteristics of the surrounding rocks at the site, which affects the accuracy of the test results. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE PRESENT APPLICATION An object of the present application is to solve at least one of the technical problems in the related art to some extent. [Means for solving the problem]

[0006] Therefore, the first objective of this application is to propose a test method for rock mass stability analysis, which can construct a rock mass model that is in line with the actual situation at the site, and can realistically respond to the overall stability situation in the disturbance of the surrounding rock mining site, thereby providing security for coal mining.

[0007] The second objective of this application is to propose a test system for rock mass stability analysis.

[0008] In order to achieve the above object, the present application provides a test method for rock mass stability analysis, the test method comprising: Acquiring bare (exposed) structural surface image information (bare structural surface image information) and internal structural surface radar information (internal structural surface radar information) of a rock mass; Constructing a three-dimensional model of the bare structural surface of the rock mass (a three-dimensional model of the bare structural surface) based on the bare structural surface image information; determining crack structure information based on the internal structure surface radar information; Constructing a structural surface spatial information probability model (probabilistic model of spatial information of structural surface) based on the bare structural surface three-dimensional model and the crack structural information; Determining model manufacturing information of a rock mass physical large-scale model (rock mass physical large-scale model) based on the structural surface spatial information probability model, wherein the model manufacturing information includes crack manufacturing information and rock mass manufacturing information, the crack manufacturing information includes crack position information and crack manufacturing material, and the rock mass manufacturing information includes rock mass position information and rock mass manufacturing material; Using polyvinyl alcohol as a crack manufacturing material, and constructing a rock mass skeleton using 3D printing technology based on crack position information; adopting a rock-like material as a rock mass manufacturing material, filling the rock mass skeleton with the rock-like material based on the rock mass position information, embedding microtubes in the rock-like material, embedding one end of the microtube in the rock-like material, connecting the other end of the microtube to a water source, and controlling the flow rate of the water source through the microtube by a preset constant pressure constant speed pump (constant pressure and constant speed pump) to manufacture a rock mass physics large-scale model; Obtaining on-site feedback information on disturbance of the rock mass at the mining site; determining a test pressure for the rock physics large scale model based on the in-situ feedback information, wherein the test pressure includes a test ambient pressure, a test axial pressure, and a test seepage pressure to test against the rock physics large scale model based on the test pressure; and obtaining test feedback information of the rock physics large scale model at the test pressure.

[0009] In order to achieve the above object, the present application provides a test system for rock mass stability analysis, the test system comprising: A probabilistic model construction module (probabilistic model construction module) that acquires bare structural surface image information and internal structural surface radar information of a rock mass, and constructs a structural surface spatial information probabilistic model of the rock mass based on the bare structural surface image information and the internal structural surface radar information; a physical model manufacturing module (physical model manufacturing module) for determining model construction information of a rock physics large-scale model based on the structural surface spatial information probability model, and manufacturing the rock physics large-scale model based on the model construction information; a test pressure application module (test pressure application module) for obtaining on-site feedback information of disturbance of the rock mass at a mining site, determining a test pressure for the rock physics large-scale model based on the on-site feedback information, and testing the rock physics large-scale model based on the test pressure; and a model deformation monitoring module for obtaining test feedback information of the rock physics large scale model at the test pressure.

[0010] The rock mass stability analysis test method and system provided in the present application obtains the bare structural surface image information and the internal structural surface radar information of the rock mass, constructs a structural surface spatial information probability model that is adapted to the rock mass structure at the site, and manufactures a rock mass physics large-scale model based on the structural surface spatial information probability model. Based on the on-site feedback information of the rock mass obtained by disturbance at the mining site, the test pressure applied to the rock mass physics large-scale model is determined, which is more adapted to the actual situation, and the rock mass physics large-scale model can respond more realistically to the feedback information such as the stress-strain data of the rock mass. The configuration of the present application can construct a rock mass model that is adapted to the actual situation at the site, and can respond realistically to the stability situation of the rocks around the site, thereby providing security for coal mining. [Brief description of the drawings]

[0011] [Figure 1] 1 is a flow chart of a test method for rock mass stability analysis. [Diagram 2] 1 is a flowchart of steps S201 to S202 in a testing method for analyzing stability of a rock mass. [Diagram 3] 1 is a flowchart of steps S301 to S302 in a testing method for analyzing stability of a rock mass. [Figure 4] FIG. 1 is a structural schematic diagram of a test stand in a test method for rock mass stability analysis. [Diagram 5] FIG. 1 is a modular schematic diagram of a testing system for rock mass stability analysis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a test method and system for analyzing stability of rock masses according to an embodiment of the present application will be described with reference to the drawings.

[0013] Figure 1 is a flow chart of the test method for rock mass stability analysis.

[0014] As shown in Figure 1, the method includes: S101, acquiring bare structural surface image information and internal structural surface radar information of the rock mass; S102, constructing a probability model of spatial information of the structural surface of the rock mass based on the bare structural surface image information and the internal structural surface radar information; S103: determining model construction information of a rock physics large-scale model based on the structural surface spatial information probability model, and manufacturing a rock physics large-scale model based on the model manufacturing information; S104 obtaining on-site feedback information on disturbance of the rock mass at the mining site; S105 determining a test pressure for the rock physics large-scale model based on the field feedback information, and testing the rock physics large-scale model based on the test pressure; and S106 obtaining test feedback information of the rock physics large scale model at the test pressure.

[0015] In steps S101 to S102, bare structural surface image information and internal structural surface radar information of the rock mass are acquired, and a structural surface spatial information probability model of the rock mass is constructed based on the bare structural surface image information and the internal structural surface radar information.

[0016] A 3GSM 3D rock mass non-contact photography measurement system and a 3D laser scanning system are used to perform high-speed and precise photography measurements of typical mine rock mass structural surfaces, and to supplement artificial measurement technology to obtain measurement results (i.e., image information of the bare structural surface of the rock mass).

[0017] The bare structural surface image information includes the occurrence and actual distribution of each group of rock mass structural surfaces, specifically, the calculated trace length, dip angle, pitch and joint line density stripe of each group of rock mass structural surfaces. All the acquired rock mass structural surfaces are grouped, including Class 3 - small-scale secondary faults, Class 4 - discontinuous distribution structural surfaces with a certain degree of connectivity, and Class 5 - microcracks with poor connectivity. The grouping is performed based on the occurrence cluster, and the trace length, average occurrence, pitch and fracture distance of each group of rock mass structural surfaces are calculated, and a 3D structure model of the bare structural surface is constructed using a 3D image processing analysis system.

[0018] Based on the measurement of the exposed structural planes of rock masses, use ground penetrating radar to non-destructively explore the internal structural space of rock masses, obtain the radar information of the internal structural planes, obtain the internal structure of rock masses based on the inversion of the radar information of the internal structural planes, and at the same time use a digital drill boroscope to drill and correct the inverted internal structure of rock masses to determine the crack structure information. Combine the 3D structural model of the exposed structural planes with the crack structure information, and further perform statistical analysis to construct a probability model of the spatial information of the structural planes.

[0019] Construct a probability model of the spatial information of the structural planes of rock masses with a certain crack roughness using the following formula.

Number

[0020] However, z(x,y) represents the height of the crack rough surface. x and y are the displacement coordinates of the crack. L is the length of the crack. a is the amplitude of the height of the crack fractal surface. D represents the fractal dimension of the 3D crack (2 < D < 3). η is the frequency density parameter of the crack, and this value is greater than 1. The M value represents the number of overlapping rough peaks on the rock mass surface. n represents the frequency index. φm,n represents the random phase of the crack.

[0021] In step S103, determine the model construction information of the large-scale physical model of rock masses based on the probability model of the spatial information of the structural planes, and manufacture the large-scale physical model of rock masses based on the model construction information. After constructing the probability model of the spatial information of the structural planes of rock masses, the large-scale physical model of rock masses can be manufactured based on the probability model of the spatial information of the structural planes.

[0022] First, determine the model manufacturing information of the large-scale physical model of rock masses based on the probability model of the spatial information of the structural planes. The model manufacturing information includes crack manufacturing information and rock mass manufacturing information. The crack manufacturing information includes crack position information and crack manufacturing materials. The rock mass manufacturing information includes rock mass position information and rock mass manufacturing materials.

[0023] As shown in Figure 2, the manufacturing steps of the large-scale physical model of rock masses are S201 uses polyvinyl alcohol as a crack manufacturing material and constructs a rock mass skeleton using 3D printing technology based on crack position information; S202, employing rock-like material as rock mass manufacturing material, and filling the rock mass skeleton with the rock-like material based on the rock mass position information to manufacture a rock mass physical large-scale model.

[0024] Based on the constructed structural surface spatial information probability model of the rock mass, the positions of all cracks in the structural surface spatial information probability model are determined, and the crack structure of the structural surface spatial information probability model of the rock mass is printed using a 3D printer, and the crack structure is used as the rock mass skeleton. The printing material of the 3D printer is a polyvinyl alcohol material, i.e., a PVA material, which is soluble in ethanol.

[0025] Then, the printed rock mass skeleton is placed in a large-scale model testing system, and after the rock mass position information is determined, the rock mass skeleton can be laid and filled with rock-like materials, and after the laying is completed, a rock mass physics large-scale model can be obtained. The rock-like materials include gypsum, cement mortar, PLA materials, etc., and these materials can be used alone or mixed in a certain ratio to meet the construction requirements of the rock mass physics large-scale model.

[0026] In a real rock mass environment, the crack types can be divided into solid cracks and hollow cracks. Generally, solid cracks are filled with materials such as sand, while hollow cracks are not filled with materials such as sand.

[0027] In order to better meet the actual field investigation conditions at the site, a rock physics large-scale model was fabricated, as shown in Figure 3, which includes the following S301-S302: In S301, the crack type of the crack is determined based on the structural surface spatial information probability model, and the crack type includes solid crack and hollow crack; In S302, the polyvinyl alcohol material in the crack whose crack type is a hollow crack is decomposed (dissolved) to construct a physical model of the hollow crack.

[0028] From the above, it can be seen that the material for making the crack is polyvinyl alcohol (i.e., PVA material), and the PVA material is soluble in ethanol. Therefore, when it is determined that the crack type of the crack is a hollow crack, ethanol can be dropped onto the PVA material of the crack, and the PVA material can be decomposed by ethanol to form a hollow crack. When it is determined that the crack type of the crack is a solid crack, the printed crack is not processed, and at this time the PVA material can fill the crack as a filling material such as sand.

[0029] In step S104, the on-site feedback information of the disturbance of the rock mass at the mining site is obtained. After the rock physics large-scale model is constructed, it can be tested on the rock physics large-scale model. In the testing process, it is necessary to apply pressure to the rock physics large-scale model according to the pressure actually applied at the site, so as to obtain an accurate testing effect of the rock physics large-scale model.

[0030] Therefore, the small electric discharge source system is used to determine the velocity and velocity inversion diagram of seismic wave propagation at each position of the actual rock mass structural surface corresponding to the rock mass physical large-scale model in the exploration area by using the seismic wave tomography method, and the high stress area of ​​the rock mass is determined in the velocity inversion diagram based on the corresponding relationship between the wave speed anomaly coefficient of the seismic wave and the rock mass stress. Focusing on the high stress area, the drill stress meter is buried at intervals of 20m. After the stress meter placement is completed, the stress online monitoring system is accessed (connected) to monitor the stress that the rock mass in the field is subjected to during the disturbance of the rock mass mining, and the rock mass stress evolution rule and groundwater dynamic evolution rule during the disturbance of the mining are comprehensively analyzed, and the disturbance of the rock mass and the disturbance of the mining site are used as the on-site feedback information.

[0031] In step S105, a test pressure for the rock physics large-scale model is determined based on the field feedback information, and the rock physics large-scale model is tested based on the test pressure. The test pressure includes a test ambient pressure, a test axial pressure, and a test seepage pressure. In rock mechanics, the ambient pressure refers to the pressure or stress intensity around the rock mass, which is usually measured and evaluated in underground mining or tunneling. The axial pressure refers to the pressure acting on the structure or rock mass along an axis, which may be due to gravity, external loads, or other factors. The seepage pressure refers to the pressure caused by the passage of liquid or gas through soil or other porous media, which may be due to the flow of liquid or gas and may affect the soil or structure. After determining the field feedback information of the disturbance of the rock mass at the mining site, an external test pressure is applied to the large-scale model based on the field feedback information to obtain the test feedback information.

[0032] As shown in FIG. 4, FIG. 4 is a structural schematic diagram of the test stand, in FIG. 4, the test stand includes a test stand frame 3 and a base 9 for fixing a rock physics large-scale model. The rock physics large-scale model includes a crack structure 1 made of polyvinyl alcohol material and a rock-like structure 2 made of rock-like material, and an electric control stress loader 7 is provided around the rock-like structure 2, and a surrounding test ambient pressure can be applied to the rock physics large-scale model through the electric control stress loader 7, so as to simulate the ambient pressure that rock masses at different depths are subjected to. At the same time, an upper test axial pressure can be applied to the rock physics large-scale model through the upper electric control stress loader 7 to simulate the mining disturbance of rock masses in the field.

[0033] When a rock-like structure 2 is manufactured by filling a rock-like material into a rock-like skeleton based on rock-like construction position information, microtubules are embedded in the rock-like material, one end of the microtubules is embedded in the rock-like structure 2, the other end of the microtubules is connected to a water source 6, and the flow rate of the water source 6 through the microtubules is controlled by a preset constant pressure constant speed pump 10.

[0034] The microtube is divided into a water inlet tube 4 and a water outlet tube 5. In the rock physics large-scale model, a water source 6 is passed through the water inlet tube 4, and pressure is applied to the rock physics large-scale model through one end of the water inlet tube 4 to simulate the test osmotic pressure to which the rock physics large-scale model can be subjected, and the water outlet tube 5 is used to discharge water. At the same time, the water flow rate in the microtube can be controlled by the constant pressure and constant speed pump 10, thereby realizing the adjustment of the test osmotic pressure.

[0035] This will finally complete the study of the stability of deep rock masses under the action of rock mining, seepage flow and structural conditions through this test bench.

[0036] In step S106, the test feedback information of the rock mass physical large-scale model under test pressure is obtained, the test feedback information includes stress-strain information and model deformation information, the stress-strain information can provide stress-strain data of the rock mass under different load-bearing conditions, and the model deformation information can intuitively embody the model deformation information of the rock mass when subjected to test pressure, which is convenient for decision-making.

[0037] Specifically, by installing strain gauges 8 in the crack areas in the rock physics large-scale model and accessing the stress online monitoring system, the stress and strain information of the rock physics large-scale model can be obtained through the data collected by the strain gauges 8. At the same time, through the VIC-3D strain measurement system, the model deformation information of the entire rock physics large-scale model is recorded in real time, and the VIC-3D is a non-contact full-field dynamic strain measurement system, through which the model deformation information of the rock physics large-scale model can be displayed in three dimensions, which is relatively intuitive.

[0038] The beneficial effects of the present invention are as follows: (1) Based on the actual crack distribution situation of the rocks surrounding the site, a structural surface spatial information probability model of the rocks surrounding the site is constructed, and a rock physics large-scale model is constructed. (2) A 3D printer is used to print the crack structure 1 of the rock mass structural surface spatial information probability model, and the printing material is PVA. Taking advantage of the property that PVA material dissolves in ethanol, the crack structure 1 is divided into hollow cracks and solid cracks. At the same time, the constructed physical large-scale model takes into account the roughness of the cracks and is more in line with the actual conditions on site. (3) A large-scale physical test bench was constructed to measure the mining stress, seepage pressure and other information of the surrounding rocks at the site in terms of various factors such as mining disturbance, high seepage pressure and discontinuous structural surfaces. Based on the measured data, ambient pressure, axial pressure and seepage pressure were applied to the large-scale model, and simulation tests were conducted on the various stability conditions of the large-scale rock physics model. The test results obtained are more scientific and reliable.

[0039] To realize the above embodiment, the present application also proposes a testing system for rock mass stability analysis.

[0040] Figure 5 is a modular schematic diagram of the rock mass stability analysis testing system.

[0041] As shown in FIG. 5, the system includes: a probabilistic model construction module 11 that acquires bare structural surface image information and internal structural surface radar information of the rock mass, and constructs a structural surface spatial information probabilistic model of the rock mass based on the bare structural surface image information and the internal structural surface radar information; a physical model production module 12 that determines model construction information of a rock mass physics large-scale model based on the structural surface spatial information probabilistic model, and manufactures the rock mass physics large-scale model based on the model construction information; a test pressure application module 13 that acquires on-site feedback information of disturbance of the rock mass at the mining site, determines a test pressure for the rock mass physics large-scale model based on the on-site feedback information, and tests the rock mass physics large-scale model based on the test pressure; and a model deformation monitoring module 14 that acquires test feedback information of the rock mass physics large-scale model at the test pressure.

[0042] The description of the rock mass stability analysis test method embodiment above also applies to the rock mass stability analysis test system of the corresponding embodiment, and will not be described further here. [Explanation of symbols]

[0043] 1. Crack structure 2. Rock-like Structure 3 Frame 4 Water inlet pipe 5 Water outflow pipe 6 Water source 7 Electrically Controllable Stress Loader 8 Strain Gauges 9 Base 10 Constant pressure constant speed pump 11 Probabilistic Model Building Module 12 Physical Model Manufacturing Module 13 Test pressure application module 14 Model Deformation Monitoring Module

Claims

1. Acquiring bare structural surface image information and internal structural surface radar information of the rock mass; Constructing a three-dimensional model of the bare structural surface of the rock mass based on the bare structural surface image information; determining crack structure information based on the internal structure surface radar information; Constructing a structural surface spatial information probability model based on the bare structural surface three-dimensional model and the crack structural information; Determining model manufacturing information of a rock mass physical large-scale model based on the structural surface spatial information probability model, wherein the model manufacturing information includes crack manufacturing information and rock mass manufacturing information, the crack manufacturing information includes crack position information and crack manufacturing material, and the rock mass manufacturing information includes rock mass position information and rock mass manufacturing material; Using polyvinyl alcohol material as a crack manufacturing material, and constructing a rock mass skeleton using 3D printing technology based on the crack position information; adopting a rock-like material as a rock mass manufacturing material, filling the rock mass skeleton with the rock-like material based on the rock mass position information, embedding microtubes in the rock-like material, embedding one end of the microtube in the rock-like material, connecting the other end of the microtube to a water source, and controlling the flow rate of the water source through the microtube by a preset constant pressure constant speed pump to manufacture a rock mass physics large-scale model; Obtaining on-site feedback information on disturbance of the rock mass at the mining site; determining a test pressure for the rock physics large scale model based on the in-situ feedback information, wherein the test pressure includes a test ambient pressure, a test axial pressure, and a test seepage pressure to test against the rock physics large scale model based on the test pressure; obtaining test feedback information of the rock physics large scale model at the test pressure; and A test method for rock mass stability analysis, comprising:

2. The step of testing the rock physics large scale model based on the test pressure comprises: applying a test ambient pressure and a test axial pressure to the rock physics large-scale model based on an electrically controllable stress loader provided outside the rock physics large-scale model; applying a test osmotic pressure to the rock physics large-scale model based on the constant pressure, constant speed pump and the microtube; 2. The test method for rock mass stability analysis according to claim 1, comprising:

3. The test feedback information includes stress-strain information and model deformation information, and obtaining test feedback information of the rock physics large scale model at the test pressure includes: acquiring stress-strain information of the rock physics large-scale model at the test pressure based on strain gauges preset in the rock physics large-scale model; acquiring model deformation information of the rock physics large-scale model at the test pressure based on a preset strain measurement system; 2. The test method for rock mass stability analysis according to claim 1, comprising:

4. A rock mass stability analysis testing system using the rock mass stability analysis testing method according to any one of claims 1 to 3, comprising: A probabilistic model construction module that acquires bare structural surface image information and internal structural surface radar information of a rock mass, and constructs a structural surface spatial information probabilistic model of the rock mass based on the bare structural surface image information and the internal structural surface radar information; a physics model manufacturing module for determining model construction information of a rock physics large-scale model based on the structural surface spatial information probability model, and manufacturing the rock physics large-scale model based on the model construction information; a test pressure application module for obtaining on-site feedback information of a disturbance of the rock mass at a mining site, determining a test pressure for the rock physics large-scale model based on the on-site feedback information, and testing the rock physics large-scale model based on the test pressure; a model deformation monitoring module for obtaining test feedback information of the rock physics large scale model at the test pressure; A test system for rock mass stability analysis comprising:

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