Similar simulation test device considering solid-liquid coupling effect of bottom plate aquifer

Abstract

The utility model discloses an analog simulation test device considering the solid-liquid coupling effect of a floor aquifer, which comprises a model frame, the bottom and two sides of the model frame are all provided with constraint support structures, and the model frame comprises a rock stratum simulation layer, a rock stratum simulation layer and a rock stratum simulation layer, the aquifer simulation mechanism is located below the rock stratum simulation layer and comprises a water bag, rigid gaskets are arranged at the top and the bottom of the water bag respectively, and a plurality of sets of springs are arranged between the rigid gaskets at intervals; the conveying mechanism is connected with the water bag, injects water into the water bag and ensures that the water pressure in the water bag is stable; and the lateral water outlet pipe is positioned in the rock simulation layer and is connected with the water bag through a water guide hose. According to the utility model, the solid-liquid coupling effect of the aquifer is fully considered, and solid particles are innovatively added into the water bag for simulating the aquifer, so that the damage depth of the bottom plate under the condition of working face bottom plate under-pressure mining can be more accurately predicted, and a basis is provided for researching the feasibility of working face under-pressure mining.

Description

Technical Field

[0001] This utility model relates to a similarity simulation test device, and more particularly to a similarity simulation test device that considers the solid-liquid coupling effect of the bottom plate aquifer. Background Technology

[0002] In the field of mining engineering, similar material simulation tests are one of the main methods for studying mine pressure and observing the failure characteristics of the roof and floor of the working face. The main principle is as follows: according to the actual strata prototype in the study area, similar materials such as river sand and gypsum are used to simulate the lithology of different rock layers, and their size is reduced according to a certain similarity ratio. Then, the simulated rock layers are stacked to form a complete similar material simulation test model. In this model, underground engineering operations such as roadway excavation and coal seam mining can be simulated, and the disturbance and damage of underground engineering construction to the surrounding rock can be observed.

[0003] When using similar material simulation experiments to study coal mining technology in confined water, the accurate simulation of the aquifer is crucial to ensuring the experimental results. The differences in properties between the aquifer and other rock strata mainly stem from the solid-liquid coupling effect. The interaction between the fluid and solid fields produces the solid-liquid coupling effect, a problem widely present in underground engineering, such as water inrush accidents induced by coal seam mining, surface subsidence caused by groundwater extraction, and earthquakes induced by reservoir construction. However, current similar material simulation experiments do not adequately consider the solid-liquid coupling effect of the aquifer, and the accuracy of the experiments needs improvement. Furthermore, how to accurately simulate the water pressure changes in the aquifer caused by excavation remains a challenge to be overcome in similar material simulation experiments. Utility Model Content

[0004] To address the shortcomings of the aforementioned technologies, this invention provides a similar simulation test device that considers the solid-liquid coupling effect of the aquifer in the base plate.

[0005] To solve the above technical problems, the technical solution adopted by this utility model is: a similarity simulation test device considering the solid-liquid coupling effect of the bottom aquifer, including a model frame, the bottom and both sides of which are constraint support structures, and the model frame includes:

[0006] Rock strata simulation layer mounted on the model frame;

[0007] The aquifer simulation mechanism is located below the rock strata simulation layer. The aquifer simulation mechanism includes a water bag, with rigid pads at the top and bottom of the water bag, and several sets of springs spaced apart between the rigid pads.

[0008] A conveying mechanism connected to the water bag injects water into the water bag and ensures stable water pressure inside the water bag;

[0009] The lateral water outlet pipe is located within the simulated rock strata and is connected to the water bag via a flexible water guide tube.

[0010] Preferably, the delivery mechanism includes a pressure pump and a water tank. The water tank is connected to the water inlet of the water bag via the pressure pump, and the water outlet of the water bag is connected to a water delivery hose.

[0011] Preferably, the water-conducting hoses are spaced apart and extend upward along the simulated rock strata, and multiple lateral water outlet pipes with water outlet directions perpendicular to the water-conducting hoses are provided on the water-conducting hoses.

[0012] Preferably, the top of the model frame is equipped with multiple hydraulic jacks at intervals.

[0013] Preferably, the spring is welded to the rigid washer.

[0014] Preferably, the rigid gasket is connected to the water bag by bolts.

[0015] Preferably, the water bag contains water and solid particles.

[0016] Preferably, the simulated rock layer consists of sand or gravel.

[0017] This invention proposes a similarity simulation test device that considers the solid-liquid coupling effect of the aquifer. The model fully considers the solid-liquid coupling effect of the aquifer and innovatively incorporates solid particles (rock fragments, etc.) into the water bag simulating the aquifer. The combination of spring, water bag, and rigid gasket enhances the bearing capacity and elastic recovery ability of the simulated aquifer. Under mining influence, the up-and-down movement of the spring causes changes in the volume of the water bag, thereby simulating changes in groundwater pressure and making the model more realistic. Furthermore, the addition of a lateral outlet pipe to the water-conducting hose maintains the fluidity of the internal rock strata, better simulating the mechanical properties of each rock stratum under the solid-liquid coupling effect.

[0018] This invention improves upon traditional similar material models, and the aquifer simulated by this model is more realistic. Therefore, it can more accurately predict the depth of floor failure under pressurized mining conditions, providing a basis for studying the feasibility of pressurized mining. Attached Figure Description

[0019] Figure 1 This is a simplified model diagram of the present invention.

[0020] Figure 2 This is a schematic diagram of the combination of a water bag and a spring.

[0021] In the diagram: 1. Simulated rock stratum; 2. Aquifer; 3. Spring; 4. Water bag; 5. Inlet; 6. Water tank; 7. Outlet; 8. Water guide hose; 9. Side outlet pipe; 10. Hydraulic jack; 11. Pressure pump; 12. Rigid gasket; 13. Bolt; 14. Nut. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0023] like Figure 1 The diagram illustrates a similarity simulation test apparatus considering the solid-liquid coupling effect of an aquifer at the bottom of a base plate. The apparatus includes a model frame, with constraint support structures on the bottom and sides, and multiple hydraulic jacks 10 spaced apart on the top. The model frame includes:

[0024] Rock strata simulation layer 1 is installed on the model frame; rock strata simulation layer 1 is composed of sand or gravel.

[0025] The aquifer simulation mechanism 2, located below the simulated rock strata, includes a water bag 4 containing water and solid particles. Rigid gaskets 12 are positioned at the top and bottom of the water bag 4, and several sets of springs 3 are spaced apart between the rigid gaskets 12. Figure 2 As shown, spring 3 is welded to rigid washer 12. Rigid washer 12 is connected to water bag by bolt 13.

[0026] A conveying mechanism connected to the water bag 4 injects water into the water bag and ensures stable water pressure inside the water bag;

[0027] The delivery mechanism includes a pressure pump 11 and a water tank 6. The water tank 6 is connected to the water inlet 5 of the water bag through the pressure pump 11, and the water outlet 7 of the water bag is connected to the water guiding hose 8.

[0028] A lateral water outlet pipe 9 is located within the simulated rock strata layer 1. The lateral water outlet pipe 9 is connected to the water bag via a water guide hose 8. The water guide hose 8 is spaced out and extends upward along the simulated rock strata layer. Multiple lateral water outlet pipes 9 with water outlet directions perpendicular to the water guide hose 8 are installed on the water guide hose 8.

[0029] The model was tested on a two-dimensional similar material simulation test bench. The model's dimensions are: length × width × height = 3.0m × 0.4m × 2.0m. Vertical stress compensation was achieved by applying pressure using multiple (7) hydraulic jacks at the upper boundary of the model. The bottom and sides of the model are constrained support structures. See the model diagram below. Figure 1The model uses plaster, river sand, etc. to simulate rock strata, simulating layer 1. In the similar material simulation experiment, water bag 4 and the solid-liquid mixture in the water bag are used to simulate the bottom aquifer 2. The aquifer 2 is supported by spring 3 and rigid gasket 12. Spring 3 and rigid gasket 12 are connected by welding. Rigid gasket 12 can make the aquifer more uniformly stressed. Water bag 4 and rigid gasket 12 are connected by bolt 13 and nut 14.

[0030] The presence of springs gives the simulated aquifer a certain bearing capacity and reaction force; the water bag is mainly used to store the fluid inside, which consists of water and solid particles (rock fragments, etc.). The water flow interacts with the solid particles. On the one hand, the presence of water softens the solid particles, and on the other hand, the presence of solid particles changes the distribution of water flow, thus simulating the solid-liquid coupling effect of the bottom aquifer well.

[0031] The water bag 4 is equipped with an inlet 5 and an outlet 7. The pressure pump 11 is connected to the water tank 6 and the inlet 5 of the water bag. When water is injected into the water bag 4, the pressure pump 11 is turned on to continuously inject water from the water tank 6 into the water bag 4 until it is full. By controlling the output pressure of the pressure pump 11, the water pressure in the water bag 4 can be kept stable. The outlet 7 is connected to the water guide hose 8. The length of the water guide hose 8 can be changed according to the specific needs of the test. When laying the rock layer, the overlying rock layer of the aquifer should be used to squeeze the water guide hose to close its internal channel. The water guide hose is connected to a lateral outlet pipe 9, which can transfer the fluid in the water guide hose to each rock layer.

[0032] Before coal seam excavation, stress and displacement sensors are deployed in the study area according to the needs of the experiment to record the changes in the surrounding rock in real time. In addition, high-speed cameras are used to take pictures of the surrounding rock at different stages of coal seam excavation and to detect the depth of floor damage.

[0033] The simulation process of this experimental model is as follows: Solid particles such as rock fragments are loaded into a water bag. Water is injected into the water bag through a pressure pump and a water tank until the water bag is inflated, allowing the solid particles and water inside the water bag to mix thoroughly, forming a solid-liquid mixture to simulate the aquifer under the solid-liquid coupling effect. Then, rock strata are laid. During this process, spring 3 and rigid gasket 12 are used to support the water bag 4 and the aquifer simulated by the solid-liquid mixture inside. The water pressure in the water bag is stably supplied by the water tank 6 and the pressure pump 11. The outlet 7 of the water bag is connected to a water-conducting hose 8. After the coal seam is excavated, under the influence of mining, the solid-liquid mixture in the water bag flows along the water-conducting hose, and the lateral outlet pipe 9 transmits it to each rock stratum, thus simulating the solid-liquid coupling effect of each rock stratum and realizing fluid visualization. During the coal seam excavation process, the damage to the coal seam floor and the water level changes in the water-conducting hose can be observed in real time.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The solid-liquid coupling effect of the aquifer is fully considered. The water bag contains not only liquid water but also solid particles (rock fragments, etc.). The flow pattern of pure liquid water is not the same as that of fluids in a solid-liquid mixed mode. On the one hand, the presence of water softens solid particles; on the other hand, the presence of solid particles changes the distribution of water flow. In the actual downhole environment, the water in the aquifer inevitably carries away fine solid particles from the surrounding rock strata when it flows. Therefore, this design is more realistic.

[0036] 2. The side outlet pipe of the water-conducting hose allows the fluid in the water bag to flow dynamically in each rock layer, which better simulates the effect of solid-liquid coupling on each rock layer and realizes the visualization of the fluid.

[0037] 3. The combined design of water bag, spring and rigid gasket gives the aquifer a certain bearing capacity and elastic recovery ability. At the same time, when the coal seam is excavated, the mine pressure causes the spring to move up and down, which drives the water bag volume change and the aquifer water pressure change, which is more in line with the water pressure change mode of the underground aquifer.

[0038] The above embodiments are not intended to limit the present utility model, nor is the present utility model limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the technical solution of the present utility model are also within the protection scope of the present utility model.

Claims

1. A similarity simulation test device considering the solid-liquid coupling effect of the aquifer at the bottom, comprising a model frame, wherein the bottom and both sides of the model frame are constraint support structures, characterized in that: The model frame includes: Rock strata simulation layer (1) installed on the model frame; The aquifer simulation mechanism (2) located below the rock stratum simulation layer includes a water bag (4), and rigid pads (12) are respectively provided at the top and bottom of the water bag (4), and several sets of springs (3) are provided between the rigid pads (12). A conveying mechanism connected to the water bag (4) injects water into the water bag and ensures stable water pressure inside the water bag; A lateral water outlet pipe (9) is located within the simulated rock layer (1), and the lateral water outlet pipe (9) is connected to the water bag via a water guide hose (8).

2. The similarity simulation test device considering the solid-liquid coupling effect of the aquifer at the bottom plate according to claim 1, characterized in that: The conveying mechanism includes a pressure pump (11) and a water tank (6). The water tank (6) is connected to the water inlet (5) of the water bag through the pressure pump (11), and the water outlet (7) of the water bag is connected to the water guide hose (8).

3. The similarity simulation test device considering the solid-liquid coupling effect of the aquifer at the bottom plate according to claim 1, characterized in that: The water-conducting hoses (8) are spaced apart and extend upward along the simulated rock strata. Multiple lateral water outlet pipes (9) with the water outlet direction perpendicular to the water-conducting hoses are provided on the water-conducting hoses (8).

4. The similarity simulation test device considering the solid-liquid coupling effect of the aquifer at the bottom plate according to claim 1, characterized in that: The top of the model frame is equipped with multiple hydraulic jacks (10) spaced apart.

5. The similarity simulation test device considering the solid-liquid coupling effect of the aquifer at the bottom plate according to claim 1, characterized in that: The spring (3) is welded to the rigid washer (12).

6. The similarity simulation test device considering the solid-liquid coupling effect of the aquifer at the bottom plate according to claim 5, characterized in that: The rigid gasket (12) is connected to the water bag by bolts (13).

7. The similarity simulation test device considering the solid-liquid coupling effect of the aquifer at the bottom plate according to claim 1, characterized in that: The water bag (4) contains water and solid particles.

8. The similarity simulation test device considering the solid-liquid coupling effect of the aquifer at the bottom plate according to claim 1, characterized in that: The simulated rock layer (1) is composed of sand or gravel.

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