A method for constructing a large-scale experimental model of the thermophysical response of rock mass structures

Abstract

The present invention provides a method for constructing a large experimental model of the thermophysical response of a rock mass structure and an experimental method. By laying regular granite blocks of different specifications and sizes to simulate the underlying framework of the rock mass, a set of opposite sides of the simulated underlying framework of the rock mass are reserved with vacant spaces for constructing transverse fissures and longitudinal fissures of different lengths to simulate the true shape of the rock mass. The experimental method obtains the surface image of the experimental model by drone shooting and the thermal infrared information of the real mountain by drone shooting. By comparing the infrared information of the model fissures with the infrared information of the real mountain, the fissure conditions of the real mountain can be predicted. At the same time, by combining the temperature and humidity information of the model with the infrared information, the humidity and fissures inside the real mountain can be predicted, and the hazards of mountain peeling caused by large fissures and high humidity can be prevented in advance. At the same time, by combining the temperature and humidity of the model with the infrared information, the heat conduction characteristics of the rock mass structure can also be comprehensively monitored.

Description

Technical Field

[0001] The present invention relates to the field of rock mass structure exploration, and particularly to a method for building a large experimental model of the thermophysical response of rock mass structures. Background Art

[0002] The stability and integrity of rock mass structures are important research topics in fields such as geothermal energy development, CO2 geological sequestration, groundwater seepage, and slope stability. In these fields, the formation and development of rock mass fractures and the migration behavior of water vapor have important effects on the mechanical properties and stability of rock masses. To deeply understand the behavioral characteristics of rock mass fractures, experimental and numerical simulation studies are usually required. In the natural environment, the formation and development of rock mass fractures are affected by various factors, including the natural stress field, temperature changes, and humidity conditions. Although existing indoor experiments can precisely control experimental conditions, they often have difficulty fully simulating the complex conditions in the natural environment, and at the same time, their scales are relatively small, and there is no physical model that can simulate large-scale rock mass structures in the field. Summary of the Invention

[0003] To solve the above technical problems, the present invention proposes a method for building a large experimental model of the thermophysical response of rock mass structures,

[0004] S1: Lay a simulated rock mass bottom frame by paving regular granite blocks of different specifications and sizes. Leave empty spaces for building horizontal fractures of different lengths on a set of opposite sides of the simulated rock mass bottom frame. Stack several layers of fracture simulation modules of corresponding lengths at the empty spaces of the horizontal fractures of different lengths. Place filling layers between the stacked fracture simulation modules. The upper two layers of filling layers form 4 groups of thick horizontal fractures, and the lower two layers of filling layers form 4 groups of thin horizontal fractures; Fill sand, soil, sand-soil mixture, and one group of empty spaces respectively in the four groups of horizontal fractures in the upper two layers, and fill sand, soil, sand-soil mixture, and one group of empty spaces respectively in the four groups of horizontal fractures in the lower two layers;

[0005] S2: Continue to lay multiple layers of structures along the height direction of the simulated rock mass bottom frame by granite blocks. Leave gaps between the stacked granite blocks to form vertical fractures. The vertical fractures extend from the side of the simulated rock mass bottom frame to the inside; The vertical fractures are located on another set of opposite sides of the simulated rock mass bottom frame;

[0006] S3: Set up water vapor field monitoring units in the horizontal fractures, vertical fractures, and granite blocks.

[0007] Preferably, the simulated rock mass bottom frame includes a first opposite side and a second opposite side. The empty spaces for horizontal fractures are respectively located at the two first opposite sides, and the vertical fractures are respectively located at the two second opposite sides.

[0008] Preferably, the longitudinal fissures on one second opposite side have the same fissure width but different extension lengths, and the longitudinal fissures on the other second opposite side have the same extension lengths but different fissure widths.

[0009] Preferably, in S3, the water vapor field monitoring unit is also arranged in the granite. An opening is made on the granite block at the placement position, and the communication line of the water vapor field monitoring unit is led out from the hole and externally connected to the acquisition terminal.

[0010] Preferably, the hole is filled with epoxy resin material.

[0011] Preferably, the fissure simulation module is composed of arranged granite blocks.

[0012] Preferably, several groups of water vapor field monitoring units are arranged in each group of transverse fissures, longitudinal fissures, and the granite.

[0013] Preferably, the water vapor field monitoring unit is located at the 1 / 8 position in the direction of the vertical fissure surface and the 1 / 4 position parallel to the fissure surface of each transverse fissure, and there are two symmetrically arranged sensors. Three sensors are also arranged at the central position and the two inner corner positions close to the interior of each transverse fissure. A total of five sensors are arranged for each transverse fissure.

[0014] Preferably, there are 6 water vapor field monitoring units. Two are located at the 1 / 8 position in the direction of the vertical fissure surface close to both sides of each longitudinal fissure, two are located at the 1 / 2 position in the direction of the vertical fissure surface on the center line of the longitudinal fissure, and two are located at the two inner corner positions close to the interior.

[0015] An experimental method for the thermophysical response of a rock mass structure

[0016] S1: Build the experimental model as described above outdoors. Through the water vapor field monitoring units in the transverse gaps and longitudinal gaps, the temperature and humidity information of each size fissure and the overall model are monitored in real time, and then exported for analysis and processing to obtain the spatio-temporal distribution and dynamic change characteristics of the temperature and humidity of the model.

[0017] S2: Obtain the surface image of the experimental model by using a drone. Through the high-resolution thermal infrared camera and image analysis software on the drone, the side thermal infrared information of the experimental model is taken on the four sides of the experimental model respectively. The route planning photography is carried out on the top of the model. The flight route is set in advance to make it fly automatically to collect the thermal infrared information on the top of the model. The image analysis software analyzes and processes the image acquisition information to obtain the thermal infrared information of the surface of the experimental model, especially the fissure part. Record the different humidities corresponding to different infrared information positions.

[0018] S3: Obtain the thermal infrared information of the real mountain body through the automatic flight route of the drone. By comparing the thermal infrared characteristics of the experimental model with those of the rock, quickly distinguish whether there are cracks in the slope body. At the same time, combine the temperature and humidity information obtained by the temperature and humidity sensors of the model and the thermal infrared image acquisition data, record the corresponding relationship between the temperature and humidity and the infrared image, monitor the heat conduction characteristics of the rock mass structure, and predict the humidity and cracks inside the real rock mass according to the temperature and humidity information and the infrared image acquisition data of the model.

[0019] The construction method and experimental method of the large experimental model for the thermophysical response of the rock mass structure proposed by the present invention have the following beneficial effects: Placing this large physical experimental model outdoors can fully simulate the complex conditions in the natural environment and obtain data closest to the field site. Use several natural regular granite blocks to stack and form to truly reproduce the shape and characteristics of the field rock slope. The rock mass crack simulation module fills some horizontal cracks with soil and sand materials to simulate cracks with different parameters in the field. According to the comparison of the infrared information detected by the model and the infrared information obtained by detecting the real mountain body, the internal crack conditions of the real mountain body can be predicted. Thus, these two rocks and the cracks in the middle can be prevented in advance to prevent disasters such as spalling and causing harm to people.

[0020] At the same time, combine the temperature and humidity data obtained by the temperature and humidity sensors set in the model. What thermal infrared characteristics do the cracks generally present when the humidity is too high? Generalize it to the field mountain body. After corresponding to this characteristic, these two rocks and the cracks in the middle can be prevented in advance to prevent disasters such as spalling. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for description in the embodiments.

[0022] Figure 1 It is the overall schematic diagram of the experimental model in the specific embodiment of the present invention;

[0023] Figure 2 It is the schematic diagram of the construction process of the first layer of the experimental model in the specific embodiment of the present invention;

[0024] Figure 3 It is the schematic diagram of the bottom layer framework of the rock mass in the specific embodiment of the present invention;

[0025] Figure 4 It is the schematic diagram of each crack simulation module in the specific embodiment of the present invention;

[0026] Figure 5 It is the top view schematic diagram of the layout points of the first and fourth layers of the water vapor field monitoring unit of the monitoring module in the specific embodiment of the present invention;

[0027] Figure 6Schematic top view of the layout points of the second and third layers of the water vapor field monitoring unit in the monitoring module in a specific embodiment of the present invention;

[0028] Figure 7 Schematic working principle diagram of the mid-infrared thermal imager in the thermal infrared monitoring unit of the monitoring module in a specific embodiment of the present invention;

[0029] Figure 8 Flow chart of the experimental method of the present invention;

[0030] Figure 9 Arrangement schematic diagram of the water vapor field monitoring unit of the longitudinal fissure of the present invention;

[0031] Figure 10 Distribution schematic diagram of the filling material on the first opposite side A of the present invention;

[0032] Figure 11 Distribution schematic diagram of the filling material on the first opposite side C of the present invention;

[0033] Wherein, 1, 2, granite blocks; 3, transverse fissure; 41, 42, 43, transverse fissure vacancies; 5, longitudinal fissure; 6, water vapor field monitoring unit; 7, filling layer; 71, sand; 72, soil; 73, sand and soil mixture; 74, vacant; 8, object; 9, radiation line; 10, lens; 11, grating; 12, detector; 13, infrared thermal image. Detailed implementation mode

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0035] Embodiment

[0036] The present invention proposes a method for building a large experimental model of the thermophysical response of a rock mass structure.

[0037] S1: Lay a simulated rock mass bottom frame through regular granite blocks of different specifications and sizes. There are about 11 specifications for the size of the granite blocks. According to the specific laying size, different granite specifications are selected. A set of opposite sides of the simulated rock mass bottom frame are reserved with transverse fissure vacancies of different lengths, and several layers of corresponding length fissure simulation modules are stacked at the transverse fissure vacancies of different lengths. In this embodiment, the thickness of the thin transverse fissure is 1 cm, and the thickness of the thick transverse fissure is 3 cm. It can also be designed with other thicknesses, not limited to the above two thicknesses.

[0038] In this embodiment, the structure in this embodiment is as Figure 3As shown, it is of course not limited to the size of this embodiment. Granite base blocks are arranged and formed into a square structure, and three groups of transverse fissure spaces are formed on the opposite sides of the square structure. This side is defined as the first opposite side A and the first opposite side C, while the two sides without transverse fissure spaces are defined as the second opposite side B and the second opposite side D. The lengths of the three groups of transverse fissure spaces are 50 cm, 100 cm, and 150 cm respectively, and they are formed by stacking through the fissure simulation module. Specifically, for the 50-cm-long fissure, a granite base block 2 is placed at the transverse fissure space 41 and continuously stacked in the height direction. Similarly, for the 100-cm transverse fissure 3, four second granite blocks are placed in a 2*2 manner on the transverse fissure space 42, and for the 150-cm transverse fissure 3, nine second granite blocks are placed in a 3*3 manner at the transverse fissure space 43. Similarly, they are all stacked up in sequence, and a filling layer 7 is arranged between adjacent two layers, forming 4 filling layers 7 from bottom to top, with 2 layers being filling layers 7 with a thickness of 1 cm and 2 layers being filling layers 7 with a thickness of 3 cm.

[0039] There are three groups of longitudinal fissures 5 on the second opposite side. The longitudinal fissures 5 refer to the direction vertically arranged on the ground, which is formed by leaving gaps in the vertical direction between adjacent stacked granite base blocks or granite base blocks 2. In this embodiment, the longitudinal fissures 5 are not filled, and the heights of the longitudinal fissures 5 are all the same at 80 cm, with four inward extension lengths: 75 cm, 125 cm, 150 cm, and 175 cm, and the width dimensions are respectively: 1 cm, 2 cm, and 3 cm. For the three layers of longitudinal fissures 5 as described above, the filling width of the second opposite side B is 2 cm, and the inward extension lengths from left to right are 75 cm, 125 cm, and 175 cm in sequence; the inward extension length of the second opposite side D is 150 cm, and the filling widths from left to right are 1 cm, 2 cm, and 3 cm in sequence. As Figure 10 , Figure 11 As shown, a filling layer is placed between the stacked fissure simulation modules. The thickness of the upper two filling layers is 3 cm. There are transverse fissures on each of the two first opposite sides A and the second opposite side C of each layer, and a total of 4 groups of thin transverse fissures are formed in two layers. The four groups of transverse fissures are respectively filled with sand 71, soil 72, sand-soil mixture 73, and vacancy 74. The lower two filling layers form 4 groups of thin transverse fissures, and the thickness of the four groups of transverse fissures in the lower two layers is 1 cm. They are respectively filled with sand 71, soil 72, sand-soil mixture 73, and a group of vacancy 74, which ensures parameter comparison of different fillers in different length parameters and thickness parameters of the fissures.

[0040] After stacking is completed, finally, as shown in Figure 1For the structure shown, a water vapor field monitoring unit 6 needs to be arranged in the horizontal gap and the vertical gap. The water vapor field monitoring unit 6 uses a high-precision temperature and humidity sensor, which consists of a collection terminal and a sensor probe, and is connected by a communication line in the middle. The sensors are arranged in four layers, which is the same as the number of layers of the horizontal fissure 3. The point positions of each layer are as shown in Figure 5 , Figure 6 . Among them, the first and fourth layers adopt the Figure 5 arrangement method, and the second and third layers adopt the Figure 6 arrangement method. The water vapor field monitoring unit is located at the 1 / 8 position in the direction of the vertical fissure surface, the 1 / 4 position parallel to the fissure surface, and the corner position of each horizontal fissure. There are two groups and they are symmetrically arranged. There are a total of five water and gas field detection units in each horizontal fissure. The arrangement on the vertical fissure is similar to that on the horizontal fissure. There are a total of 6 water vapor field monitoring units. Two are located at the 1 / 8 position in the direction of the vertical fissure surface near both sides of each vertical fissure, two are at the 1 / 2 position in the direction of the vertical fissure surface on the center line of the vertical fissure, and two are at the two corner positions near the inside. For details, see Figure 9 . It can monitor the temperature and humidity information of fissures of various sizes and the whole model in real time, and can export and analyze the data to obtain the spatio-temporal distribution and dynamic change characteristics of the temperature and humidity of the model.

[0041] For the setting of the water vapor field monitoring unit 6, 2-cm drill holes need to be drilled at the corresponding positions of each layer of a small number of the granite blocks, so as to facilitate the extension of the probe communication line of the temperature and humidity sensor to the designed point positions through the probe communication line of the temperature and humidity sensor. After the probe communication line of the temperature and humidity sensor successfully passes through the granite block with the drilled holes, the gaps left on the granite block are sealed with epoxy resin to prevent external water vapor from affecting the experimental data through the gaps.

[0042] In this embodiment, the thermal infrared monitoring unit is an unmanned aerial vehicle (UAV) close-range photogrammetry software system, which includes a high-resolution thermal infrared camera and an image analysis software installed on the UAV. The thermal infrared camera on the UAV collects images of the surface of the physical experiment model in a non-contact manner. The principle of the above collection method can refer to the high-steep slope multi-angle close-range photogrammetry method with the publication number of the applicant's prior application: CN117664086A. Its working principle is as shown in Figure 7As shown, the acquisition methods include flight path planning and fixed-point shooting. Among them, four points are set for fixed-point shooting, respectively on the four sides of the model, to capture the thermal infrared information of the sides of the model; flight path planning photography is carried out on the top of the model, and the flight path is set in advance to let it fly automatically to collect the thermal infrared information of the top of the model. The image analysis software analyzes and processes the image acquisition information to obtain the thermal infrared information of the surface of the experimental model, especially the fissure part. By comparing the thermal infrared characteristics of the fissures with those of real mountain rocks, it helps to quickly identify whether there are fissures in the slope in the field. The existence of rock mass fissures has an important impact on the mechanical properties and stability of the rock mass. When the fissure scale is large, the stability of the rock mass will also decrease, and geological disasters are likely to occur.

[0043] As Figure 8 shown, an experimental model as described above is built outdoors by the above method. Through the water vapor field monitoring unit 6 in the horizontal gap and vertical gap, the temperature and humidity information of each size fissure and the overall model is monitored in real time, and exported for analysis and processing to obtain the spatio-temporal distribution and dynamic change characteristics of the temperature and humidity of the model.

[0044] The surface image of the experimental model is obtained by drone shooting. Through the high-resolution thermal infrared camera and image analysis software on the drone, the thermal infrared information of the sides of the experimental model is captured on the four sides of the experimental model respectively; flight path planning photography is carried out on the top of the model, and the flight path is set in advance to let it fly automatically to collect the thermal infrared information of the top of the model; the image analysis software analyzes and processes the image acquisition information to obtain the thermal infrared information of the surface of the experimental model, especially the fissure part; and the temperature and humidity information at each fissure and in the granite is recorded, and the infrared information and temperature and humidity information corresponding to different fissure lengths, thicknesses, and different fillers are recorded.

[0045] The thermal infrared information of the real mountain body is obtained by the drone according to the automatic flight path. By comparing the thermal infrared characteristics of the experimental model with those of the rock, it can quickly identify whether there are fissures in the slope, and combined with the temperature and humidity information of the model, the temperature and humidity changes of the model under different environmental conditions can be predicted. What thermal infrared characteristics do the fissures generally present when the humidity is too high? Generalized to the field mountain body, corresponding to this characteristic, it indicates that the fissure in the mountain body contains a large amount of moisture, and the moisture plays a lubricating and promoting role in landslides and collapses. Therefore, these two rocks and the fissure in the middle can be prevented in advance to prevent disasters such as spalling and harm to people.

[0046] At the same time, by combining the temperature and humidity sensor and the thermal infrared image acquisition data, the heat conduction characteristics of the rock mass structure are monitored, providing an important basis for in-depth study of the thermophysical response of the rock mass structural plane under different parameters, and thus providing an important reference for deducing the internal structure of the rock mass. At the same time, it will also open up a new perspective for analyzing scientific issues such as weathering depth, freeze-thaw cycle, and geothermal conduction.

Claims

1. A method for constructing a large-scale experimental model of the thermophysical response of a rock mass structure, characterized in that: S1: Simulate the bottom layer framework of the rock mass by laying regular granite blocks of different specifications. Reserve lateral crack vacancies of different lengths on a set of opposite sides of the simulated rock mass bottom layer framework. Stack several layers of crack simulation modules of corresponding lengths at the lateral crack vacancies of different lengths. Place a filling layer between the stacked crack simulation modules. The upper two filling layers form four groups of thick lateral cracks, and the lower two filling layers form four groups of thin lateral cracks; the four groups of lateral cracks in the upper two layers are respectively filled with sand, soil, sand-soil mixture, and a set of empty spaces, and the four groups of lateral cracks in the lower two layers are respectively filled with sand, soil, sand-soil mixture, and a set of empty spaces; the simulated rock mass bottom layer framework includes a first opposite side and a second opposite side, and the lateral crack vacancies are respectively located at the two first opposite sides; S2: Continuously lay multiple layers of structures along the height direction of the simulated rock mass bottom layer framework with granite blocks. Leave gaps between the stacked granite blocks to form longitudinal cracks, and the longitudinal cracks extend from the side of the simulated rock mass bottom layer framework to the inside; the longitudinal cracks are respectively located at the two second opposite sides; the crack widths of the longitudinal cracks located at one second opposite side are the same, and the extension lengths are different, and the extension lengths of the longitudinal cracks located at the other second opposite side are the same, and the crack widths are different; S3: Set up a water vapor field monitoring unit in the lateral cracks, longitudinal cracks, and granite blocks; drill holes in the granite blocks at the placement positions, and lead out the communication lines of the water vapor field monitoring unit from the holes and externally connect them to a collection terminal; the holes are filled with epoxy resin material.

2. The method for constructing a large experimental model of the thermophysical response of a rock mass structure according to claim 1, characterized in that The crack simulation module is composed of arranged granite blocks.

3. The method for building a large experimental model of the thermophysical response of a rock mass structure according to claim 1, characterized in that, Several groups of water vapor field monitoring units are arranged in each group of lateral cracks, longitudinal cracks, and granite blocks.

4. The method for building a large experimental model of the thermophysical response of a rock mass structure according to claim 3, characterized in that, The water vapor field monitoring unit is located at the 1 / 8 position in the direction of the vertical crack surface, the 1 / 4 position parallel to the crack surface, and the corner position of each lateral crack. There are a total of five water vapor field detection units in each lateral crack and are symmetrically arranged.

5. The method for building a large experimental model of the thermophysical response of a rock mass structure according to claim 3, characterized in that, There are 6 water vapor field monitoring units, 2 are located at the 1 / 8 position in the direction of the vertical crack surface near both sides of each longitudinal crack, 2 are located at the 1 / 2 position in the direction of the vertical crack surface on the center line of the longitudinal crack, and 2 are located at the two corner positions near the inside.

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