Test method and system for rock mass stability analysis

Abstract

To provide a test method and system for rock mass stability analysis.SOLUTION: The test method includes: acquiring bare structure surface video information and internal structure surface radar information of a rock mass; building a structure surface space information probability model of the rock mass on the basis of the bare structure surface video information and the internal structure surface radar information; manufacturing a rock mass physical large scale model on the basis of the structure surface space information probability model; determining a test pressure for the rock mass physical large scale model on the basis of site feedback information of the rock mass, and testing the rock mass physical large scale model on the basis of the test pressure to simulate a stability change of a rock body; and acquiring test feedback information of the rock mass physical large scale model at the test pressure. The present application builds a rock mass model that matches the actual situation of the site of surrounding rocks, and makes the situation of stability of the rocks around the site react realistically, thereby providing security to coal mining.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present application relates to the technical field of rock mass stability analysis, and more particularly 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 disturbances, high seepage pressure, and discontinuous structural surfaces, which makes them highly susceptible to disasters such as widespread collapse of surrounding rocks and flooding. This makes the stability control of deep rock masses increasingly problematic, posing a major threat to the safe mining of coal.

[0003] Only by taking into consideration the stability of the surrounding rocks due to factors such as mining disturbance, high seepage pressure, deep rock masses, and discontinuous structural surfaces 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 experimentally analyze the deformation and fracture rules of surrounding rocks using large-scale models. 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] The purpose 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 conforms to 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, which includes: Acquiring bare (exposed) structural surface image information (bare structural surface image information) and internal structural surface radar information (internal structural surface radar information) of the 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 probabilistic 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 (a physical large-scale model of a rock mass) based on the structural surface spatial information probabilistic 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; Polyvinyl alcohol material is used as a crack manufacturing material, and a rock mass skeleton is constructed 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 microtubes in the rock-like material, connecting the other end of the microtubes to a water source, and controlling the flow rate of the water source through the microtubes by a preset constant pressure and constant speed pump (constant pressure and constant speed pump), thereby manufacturing a large-scale rock mass physics model; Obtaining on-site feedback information on disturbances of the rock mass at the mining site; determining test pressures for the rock physics large-scale model based on the in-situ feedback information, wherein the test pressures include a test ambient pressure, a test axial pressure, and a test seepage pressure, so as to test on the rock physics large-scale model based on the test pressures; 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 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 physics model manufacturing module (physics model manufacturing module) that determines model construction information for a rock physics large-scale model based on the structural surface spatial information probabilistic model, and manufactures the rock physics large-scale model based on the model construction information; a test pressure application module (test pressure application module) that acquires on-site feedback information on disturbance of the rock mass at a mining site, determines a test pressure for the rock physics large-scale model based on the on-site feedback information, and tests the rock physics large-scale model based on the test pressure; and a model deformation monitoring module (model deformation monitoring module) that obtains test feedback information of the rock physics large-scale model at the test pressure.

[0010] The rock mass stability analysis testing method and system provided herein acquires bare structural surface image information and internal structural surface radar information of the rock mass to construct a structural surface spatial information probabilistic model tailored to the rock mass structure at the site, and then constructs a rock physics large-scale model based on the structural surface spatial information probabilistic model. Based on on-site feedback information of the rock mass acquired through disturbances at the mining site, the test pressure to be applied to the rock physics large-scale model is determined, which better suits the actual situation, allowing the rock physics large-scale model to more realistically respond to feedback information such as rock mass stress-strain data. The configuration of the present application can construct a rock mass model tailored to the actual situation at the site, which can realistically respond to the stability conditions of the surrounding rocks at the site, thereby providing security for coal mining. [Brief explanation of the drawings]

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

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

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

[0014] As shown in Figure 1, the method involves: S101: acquiring bare structural surface image information and internal structural surface radar information of the rock mass; S102: constructing a spatial information probability model 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 and 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 density of each group of rock mass structural surfaces. All acquired rock mass structural surfaces are grouped, including Class 3 - small-scale secondary faults, Class 4 - discontinuously distributed structural surfaces with a certain degree of connectivity, and Class 5 - microcracks with poor connectivity. The groups are grouped based on occurrence clusters, and the trace length, average occurrence, pitch, and fracture distance of each group of rock mass structural surfaces are calculated, and a 3D structural model of the bare structural surfaces is constructed using a 3D image processing analysis system.

[0018] Based on the measurement of the bare structural plane of the rock mass, use ground penetrating radar to nondestructively explore the internal structural space of the rock mass, obtain the radar information of the internal structural plane, obtain the internal structure of the rock mass based on the inversion of the radar information of the internal structural plane, and at the same time use a digital drill boroscope to drill and correct the inverted internal structure of the rock mass to determine the crack structure information. Combine the bare structural plane three-dimensional structure model and the crack structure information, and further perform statistical analysis to construct a probability model of the structural plane spatial information.

[0019] Use the following formula to construct a probability model of the structural plane spatial information of a rock mass with a certain crack roughness.

Equation

[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 three-dimensional 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 superimposed 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 rock mass physical large-scale model based on the probability model of the structural plane spatial information, and manufacture the rock mass physical large-scale model based on the model construction information. After constructing the probability model of the structural plane spatial information of the rock mass, the rock mass physical large-scale model can be manufactured based on the probability model of the structural plane spatial information.

[0022] First, determine the model manufacturing information of the rock mass physical large-scale model based on the probability model of the structural plane spatial information. 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 rock mass physical large-scale model 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. and S202: adopting rock-like material as rock mass manufacturing material, filling the rock mass skeleton with the rock-like material based on the rock mass position information, and manufacturing a rock mass physical large-scale model.

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

[0025] The printed rock skeleton is then placed in a large-scale model testing system, and after determining the rock position, rock-like materials are used to fill the rock skeleton. Once the filling is complete, a large-scale rock physics model can be obtained. Rock-like materials include gypsum, cement mortar, PLA materials, etc. These materials can be used alone or mixed in a certain ratio to meet the requirements of the large-scale rock physics model.

[0026] In a real rock mass environment, 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 fit the actual field investigation conditions at the site, a large-scale rock physics model was fabricated as shown in Figure 3, and then the following steps S301 to S302 were included: In step 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, we can see that the material used to create the cracks is polyvinyl alcohol (i.e., PVA material), which is soluble in ethanol. Therefore, if the crack type of a crack is determined to be hollow, ethanol can be dropped onto the PVA material of the crack and the PVA material can be decomposed by the ethanol to form a hollow crack. If the crack type of a crack is determined to be solid, the printed crack is not processed, and the PVA material can be used as a filler material such as sand to fill the crack.

[0029] In step S104, on-site feedback information on rock disturbance at the mining site is obtained. After the large-scale rock physics model is constructed, it can be tested. In the testing process, pressure corresponding to the actual pressure applied at the site needs to be applied to the large-scale rock physics model, so that accurate testing results can be obtained for the large-scale rock physics model.

[0030] Therefore, a small-scale electrical discharge seismic source system and seismic tomography were used to determine the seismic wave propagation velocity and velocity inversion diagram at each location on the actual rock mass structural surface corresponding to the large-scale rock mass physics model within the exploration area. Based on the correspondence between the seismic wave velocity anomaly coefficient and rock mass stress, high-stress areas of the rock mass were initially identified in the velocity inversion diagram. Focusing on high-stress areas, drilled stress meters were buried at intervals of 20 meters. After the stress meters were installed, they were connected to an online stress monitoring system to monitor the stress experienced by the rock mass during mining disturbance. The evolutionary patterns of rock mass stress and groundwater dynamics during mining disturbance were comprehensively analyzed, providing on-site feedback information on the rock mass and mining disturbance.

[0031] In step S105, test pressures for the rock physics large-scale model are determined based on the field feedback information, and a test is performed on the rock physics large-scale model based on the test pressures. The test pressures include test ambient pressure, test axial pressure, and test seepage pressure. In rock mechanics, ambient pressure refers to the pressure or stress intensity around a rock mass, typically measured and evaluated in underground mining or tunneling construction. Axial pressure refers to the pressure acting along an axis on a structure or rock mass, which may be due to gravity, external loads, or other factors. Seepage pressure refers to the pressure resulting from the passage of liquid or gas through soil or other porous media, which may result from the flow of liquid or gas and affect the soil or structure. After determining field feedback information for 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 test feedback information.

[0032] As shown in Figure 4, Figure 4 is a structural schematic diagram of the test stand. In Figure 4, the test stand includes a test stand frame 3 and a base 9 for fixing a large-scale rock physics model. The large-scale rock physics model includes a crack structure 1 made of polyvinyl alcohol material and a rock-like structure 2 made of rock-like material. An electrically controllable stress loader 7 is installed around the rock-like structure 2. The electrically controllable stress loader 7 can apply a surrounding test pressure to the large-scale rock physics model, simulating the ambient pressure experienced by rock masses at different depths. At the same time, an upper test axial pressure can be applied to the large-scale rock physics model through the upper electrically controllable stress loader 7 to simulate the mining disturbance of the rock mass in the field.

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

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

[0035] This will finally complete the study of the stability of deep rock masses under the influence of rock mass mining, seepage flow and structural surface through this test stand.

[0036] In step S106, test feedback information of the large-scale rock mass physics 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 represent the model deformation information of the rock mass when subjected to test pressure, which is convenient for decision-making.

[0037] Specifically, by attaching strain gauges 8 to the crack areas in the rock physics large-scale model and accessing the stress online monitoring system, 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, the VIC-3D strain measurement system records the model deformation information of the entire rock physics large-scale model in real time. The VIC-3D is a non-contact full-field dynamic strain measurement system, and this system can display the model deformation information of the rock physics large-scale model 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 around the site, a structural surface spatial information probability model of the rocks around the site is constructed, and a large-scale rock physics model is constructed. (2) A 3D printer was used to print the crack structure 1 of the rock mass structural surface spatial information probabilistic model. The printing material was PVA, and by utilizing the property of PVA material being soluble in ethanol, the crack structure 1 was divided into hollow cracks and solid cracks. At the same time, the constructed physical large-scale model took into account the roughness of the cracks, which more closely matched the actual conditions on site. (3) A large-scale physical test bench was constructed to measure the mining stress, seepage pressure, and other information on the surrounding rocks at the site in response to various factors such as mining disturbance, high seepage pressure, and discontinuous structural surfaces. Based on this measurement 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 shows a modular schematic diagram of the rock mass stability analysis testing system.

[0041] As shown in Figure 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 physics model construction module 12 that determines model construction information for a rock physics large-scale model based on the structural surface spatial information probabilistic model, and manufactures the rock physics large-scale model based on the model construction information; a test pressure application module 13 that acquires on-site feedback information on disturbance of the rock mass at the mining site, determines a test pressure for the rock physics large-scale model based on the on-site feedback information, and tests the rock 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 test method embodiment for rock mass stability analysis above also applies to the test system for rock mass stability analysis of the corresponding embodiment, and will not be further described here. [Explanation of symbols]

[0043] 1. Crack structure 2. Rock-like structures 3 frames 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 probabilistic 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 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 microtubes in the rock-like material, connecting the other end of the microtubes to a water source, and controlling the flow rate of the water source through the microtubes by a preset constant pressure and constant speed pump to manufacture a large-scale rock mass physics model; Obtaining on-site feedback information on disturbances of the rock mass at the mining site; determining test pressures for the rock physics large-scale model based on the in-situ feedback information, wherein the test pressures include a test ambient pressure, a test axial pressure, and a test seepage pressure, so as to test on the rock physics large-scale model based on the test pressures; obtaining test feedback information of the rock physics large scale model at the test pressure; 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 external to the rock physics large-scale model; applying a test osmotic pressure to the rock physics large-scale model based on the constant pressure, constant rate pump and the microtubules; 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 testing system for rock mass stability analysis using the testing method for rock mass stability analysis according to any one of claims 1 to 3, wherein the testing system for rock mass stability analysis comprises: a probabilistic model construction module 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 physics model manufacturing module that determines model construction information for a rock physics large-scale model based on the structural surface spatial information probabilistic model, and manufactures the rock physics large-scale model based on the model construction information; a test pressure application module that acquires on-site feedback information of disturbances of the rock mass at a mining site, determines a test pressure for the rock physics large-scale model based on the on-site feedback information, and tests the rock physics large-scale model based on the test pressure; a model deformation monitoring module that obtains test feedback information of the rock physics large-scale model at the test pressure; A testing system for rock mass stability analysis, comprising:

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