Similar material simulation experiment rock stratum stress visual device and experiment method

Abstract

The invention relates to a similar material simulation experiment rock stratum stress visual device and an experiment method, and belongs to the technical field of similar material simulation experiments. The device comprises a water bag, a hose, an observation cylinder and an ultrasonic liquid level sensor, the water bag is connected with the observation cylinder through the hose, and the ultrasonic liquid level sensor is arranged at the top of the observation cylinder and used for collecting water level data in real time. The rock stratum stress is converted into water level change through a water pressure transmission mechanism, stress distribution visualization is achieved, the stress change of the rock stratum in the movement process can be visually seen, and the stress change condition under the set length can be observed.

Description

TECHNICAL FIELD

[0001] The present application relates to a similar material simulation experiment rock stratum stress visual device and experiment method, belongs to similar material simulation experiment technical field. BACKGROUND

[0002] In the field of rock mass engineering, it is crucial to deeply explore the mechanical phenomena and rock mass pressure distribution law of coal rock stratum to solve practical engineering problems. As a key research method, similar material simulation experiment simulates the real geological conditions on the model, studies the related mechanical phenomena, and then infers the situation in the prototype, providing theoretical basis and practical guidance for rock mass engineering production.

[0003] At present, the rock stratum stress detection technology on the market mainly relies on strain gauges. However, strain gauges are expensive and have many limitations. The installation and use of strain gauges involve complex operation procedures, and the existing technology can only display stress values with poor visualization, making it difficult for researchers to intuitively and comprehensively understand the distribution law and change trend of stress in the rock stratum. This makes it difficult to quickly and accurately judge the rock stratum stress state when facing complex geological conditions, which brings difficulties to engineering decision-making. Therefore, the present application is proposed. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a similar material simulation experiment rock stratum stress visual device and experiment method.

[0005] The technical scheme of the present application is as follows:

[0006] A similar material simulation experiment rock stratum stress visual device, comprising a water bag, a hose, an observation cylinder and an ultrasonic liquid level sensor, the water bag being connected to the observation cylinder through the hose, the top of the observation cylinder being provided with the ultrasonic liquid level sensor for real-time acquisition of water level data.

[0007] According to the present application, the water bag is provided with a water inlet hole on one side, and the water bag is used to deform and transmit pressure when subjected to pressure. The observation cylinder is a transparent cylinder for easy observation, and the surface is provided with a scale.

[0008] The experiment method of the similar material simulation experiment rock stratum stress visual device is as follows:

[0009] (1) Prepare similar materials for each layer of rock stratum and ore bed, then lay them layer by layer on the simulation experiment table according to the structure of the prototype stratum, install the stress visual device during the laying process, and obtain the initial reference pressure P0;

[0010] (2) Use the loading system of the simulation experiment table itself to conduct the experiment, record the water level difference Δh during the experiment, and obtain the pressure difference ΔP;

[0011] (3) after the experiment, take out each stress visual device, clean and prepare for next use, record data according to steps, and obtain the stress change of rock stratum in the experiment process.

[0012] According to the application, preferably, in step (1), the stress visual device installation process is as follows:

[0013] (11) assemble the stress visual device, first fill the water bag with water through the water inlet hole, then connect the water bag and the observation cylinder through the hose to form several stress visual devices, then inject water into the observation cylinder through the funnel to keep the water level of each stress visual device at the same scale, record the water level as h0, and connect each ultrasonic liquid level sensor to the computing system through the data line;

[0014] (12) before laying the target rock stratum or ore bed, first place the water bag, then lay the target ore bed or rock stratum, after laying all the ore beds and rock strata, inject water into each observation cylinder again to keep the water level of all the observation cylinders at the same scale, and record the water level as h1;

[0015] (13) calculate the initial reference pressure P0 of each target position by the following formula:

[0016] P0 = ρ·g·(h1-h0).

[0017] According to the application, preferably, in step (2), during the experiment, when the rock stratum extrudes the water bag, the pressure in the water bag increases, pushes the water to flow to the observation cylinder through the hose, causes the water level of the observation cylinder to rise, and Δh>0; on the contrary, if the stress of the rock stratum decreases, the water flows back to the water bag, and the water level decreases, and Δh<0, therefore, the quantitative relationship between the pressure difference and the water level height difference is as follows:

[0018] ΔP = ρ·g·Δh.

[0019] According to the application, preferably, in step (2), during the experiment, the experimenter can intuitively and accurately observe the pressure change in the rock stratum or ore bed by watching the rise and fall of the water level in the observation cylinder and combining the scale on the surface of the observation cylinder, and if the rock stratum breaks, the water level in the observation cylinder rapidly decreases, and the breaking time and position of the rock stratum can be quickly found.

[0020] According to the application, preferably, in step (3), the absolute value calculation formula of the stress of each target position is as follows:

[0021] P absolute = P0+ΔP

[0022] The stress change of each target position in the experiment process is calculated by the above formula, and a conclusion about the pressure change in the rock stratum or ore bed is obtained, which provides data support and reference basis for subsequent research.

[0023] The application has the following beneficial effects:

[0024] 1. This invention utilizes the water pressure transmission mechanism to convert rock stress into water level changes, thereby enabling visualization of stress distribution. It allows for a direct observation of the stress changes experienced by the rock strata during movement and also provides insights into stress changes over a given length.

[0025] 2. The present invention has a simple structure, the materials can be reused, and it is easy to install and maintain. The automated acquisition of sensor data improves efficiency. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the present invention;

[0027] Figure 2 This is a schematic diagram illustrating the usage state of the present invention.

[0028] The components include: 1. Water bladder; 2. Flexible hose; 3. Observation tube; 4. Funnel; 5. Ultrasonic liquid level sensor; 6. Simulated rock strata; 7. Simulated mineral strata; 8. Simulated experimental platform; 9. Data cable; 10. Calculation system. Detailed Implementation

[0029] The present invention will be further described below with reference to the embodiments and accompanying drawings, but is not limited thereto.

[0030] Example 1:

[0031] like Figure 1 As shown, this embodiment provides a similar material simulation experiment rock layer stress visualization device, including a water bladder 1, a hose 2, an observation cylinder 3 and an ultrasonic liquid level sensor 5. The water bladder 1 is connected to the observation cylinder 3 through the hose 2. The ultrasonic liquid level sensor 5 is installed on the top of the observation cylinder 3 for real-time acquisition of water level data.

[0032] The water bladder 1 has a water inlet on one side. The water bladder is used to transfer pressure when it deforms under pressure. The observation tube is a transparent tube for easy observation and has scales on its surface.

[0033] The experimental method and steps of the above-mentioned similar material simulation rock layer stress visualization device are as follows:

[0034] (1) Prepare similar materials for each rock layer and mineral layer. Based on the geometric, mechanical and time scales of the real engineering background, carefully measure the original rock properties of each simulated rock layer and mineral layer. The measurement includes density, strength and other properties. Based on these original rock property data, determine the appropriate similar materials. Then, on the simulation test bench 8, lay them in layers according to the prototype stratum structure. During the laying process, install a stress visualization device and obtain the initial reference pressure P0. Specifically;

[0035] (11) Assembled stress visual device, first fill the water bag 1 with water through the water inlet hole, then connect the water bag 1 and the observation cylinder 3 through the hose 2, the hose and the water bag and the observation cylinder are designed to be detachable, which is convenient for combination and installation, and a plurality of stress visual devices are formed, then water is injected into the observation cylinder 3 through the funnel 4, so that the water level of the observation cylinder 3 of each stress visual device is kept at the same scale, the water level is recorded as h0, and each ultrasonic liquid level sensor 5 is connected to the computing system 10 through the data line 9;

[0036] (12) Before laying the target rock or ore layer, first place the water bag 1, then lay the target ore or rock layer, and after laying all the ore and rock layers, water is injected into each observation cylinder 3 again, so that the water level of all the observation cylinders 3 is kept at the same scale, and the water level at this time is recorded as h1;

[0037] (13) The initial reference pressure P0 of each target position is calculated by the following formula:

[0038] P0 = p.g.(h1-h0).

[0039] Wherein, p = 1000 kg / m 3 , g = 9.8 m / s 2 .

[0040] (2) Use the loading system of the simulation experiment table itself to conduct experiments, and record the water level difference Ah during the experiment, and obtain the pressure difference AP from it;

[0041] During the experiment, when the rock layer extrudes the water bag 1, the pressure in the water bag 1 increases, pushing the water to flow to the observation cylinder 3 through the hose 2, causing the water level of the observation cylinder to rise, Ah> 0; on the contrary, if the rock stress decreases, the water flows back to the water bag, and the water level decreases, Ah< 0, so the quantitative relationship between the pressure difference and the water level difference is:

[0042] AP = p.g.Ah.

[0043] At the same time, the experimenters observe the rising and falling of the water level in the observation cylinder 3, combined with the scale on the surface of the observation cylinder 3, to intuitively and accurately observe the internal pressure change of the rock or ore layer. If the rock layer breaks, the water level in the observation cylinder 3 drops rapidly, and the fracture time and position of the rock layer are quickly found.

[0044] (3) After the experiment, take out each stress visual device, clean it and prepare for next use, record the data according to the steps, and get the stress change of the rock layer during the experiment;

[0045] The absolute value calculation formula of the stress of each target position is:

[0046] P absolute = P0 + AP

[0047] The stress variation of each target position in the experiment process is calculated by using the above formula, and the conclusion about the internal pressure variation of rock or ore layer is obtained, which provides data support and reference basis for subsequent research.

Claims

1. A stress visualization device for rock formations in similar material modeling experiments, characterized in that, Including water bag, hose, observation cylinder and ultrasonic liquid level sensor, the water bag is connected with the observation cylinder through the hose, the observation cylinder is provided with the ultrasonic liquid level sensor at the top, and is used for collecting water level data in real time.

2. The similar material analog experimental rock stress visualizer of claim 1, wherein, The water bag is provided with a water inlet hole on one side, and the water bag is used for deforming to transmit pressure, and the observation cylinder is a transparent cylinder and is provided with scales on the surface.

3. The experimental method of visualizing stress in rock strata in a similar material analog experiment of claim 2, wherein, The steps are as follows: (1) Prepare similar materials for each layer of rock and ore bed, then lay them layer by layer on the simulation experiment table according to the structure of the prototype stratum, install the stress visual device during the laying process, and obtain the initial reference pressure P0; (2) Use the loading system of the simulation experiment table itself to conduct the experiment, record the water level difference Δh during the experiment, and obtain the pressure difference ΔP; (3) After the experiment, take out each stress visual device, clean it for next use, and obtain the stress change of the rock layer during the experiment according to the recorded data.

4. The experimental method of visualizing stress in rock strata in a similar material simulation experiment according to claim 3, wherein, In step (1), the stress visual device installation process is as follows: (11) Assemble the stress visual device, first fill the water bag with water through the water inlet hole, then connect the water bag and the observation cylinder through the hose to form a plurality of stress visual devices, then inject water into the observation cylinder through the funnel to keep the water level of each stress visual device at the same scale, record the water level as h0, and connect each ultrasonic liquid level sensor to the computing system through the data line; (12) Before laying the target rock or ore bed, place the water bag first, then lay the target ore or rock bed, and then inject water into each observation cylinder again to keep the water level of all observation cylinders at the same scale, and record the water level as h1; (13) Calculate the initial reference pressure P0 of each target position by the following formula: P0=ρ·g·(h1-h0).

5. The experimental method of visualizing stress in rock strata in a similar material analog experiment of claim 4, wherein, In step (2), during the experiment, when the rock layer extrudes the water bag, the pressure in the water bag increases, pushing the water to flow to the observation cylinder through the hose, causing the water level of the observation cylinder to rise, Δh>0; on the contrary, if the stress of the rock layer decreases, the water flows back to the water bag, and the water level decreases, Δh<0, so the quantitative relationship between the pressure difference and the water level difference is: ΔP=ρ·g·Δh.

6. The experimental method of visualizing stress in rock strata in a similar material simulation experiment according to claim 5, wherein, In step (2), during the experiment, the experimenter observes the change of the water level in the observation cylinder, combines the scales on the surface of the observation cylinder, and directly and accurately observes the internal pressure change of the rock or ore bed, if the rock layer breaks, the water level in the observation cylinder decreases rapidly, and the fracture time and position of the rock layer are quickly found.

7. The experimental method of visualizing stress in rock strata in a similar material simulation experiment according to claim 6, wherein, In step (3), the absolute stress calculation formula of each target position is: P absolute = P0+ ΔP The stress change of each target position during the experiment is calculated by the above formula.

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