A model test device suitable for simulating sudden surges in water-rich sandy dolomite

Abstract

The present invention discloses a model test device suitable for simulating sudden water intrusion in water-rich sandy dolomite. The device comprises a test box with an opening at the top, a yellow clay layer within the test box, and a surrounding rock layer and a gravel layer embedded in the clay layer. A pressure plate is provided at the opening of the test box, and a water tank is mounted on the pressure plate. A movable plate is provided in the water tank, and an inlet pipe extending into the gravel layer is provided on the water tank. The device also comprises a pressure assembly, which includes a first output shaft and a second output shaft. The first output shaft is configured to be inserted into the water tank and push the movable plate to move, and the second output shaft is configured to push the water tank to squeeze the pressure plate. By simulating the differences in the evolution of multiple fields such as surrounding rock stress and water inrush during water inrush, the mechanism of water and sand inrush and the early warning information when a disaster occurs are analyzed.

Description

Technical Field

[0001] The invention relates to the technical field of engineering construction, and in particular to a model test device suitable for simulating sudden surges in water-rich sandy dolomite. Background Art

[0002] With the vigorous development of my country's economic construction, the requirements for infrastructure construction, especially transportation facilities, are constantly increasing. In the construction of infrastructure such as roads and railways, tunnels have been widely used because they have the advantages of shortening line mileage and improving traffic operation conditions. In the past decade or so, the focus of major engineering construction in my country has shifted from areas with good topographic and geological conditions to the western mountainous areas and karst regions with extremely complex topographic and geological conditions. A large number of high-risk deep and long tunnel projects are being or will be built. Due to their great burial depth, long tunnel length, and complex geological conditions, deep and long tunnel projects will encounter a series of special geological disasters during the construction process, such as: weak fracture zones, developed joints and faults, high ground stress, rock bursts, water inrush, mud inrush, sand inrush, high gas, high ground temperature and other problems. Among them, water inrush in karst tunnels is the most common and the most harmful. At the same time, my country is the country with the most extensive distribution of karst in the world. Among the tunnels built and under construction in the west, tunnels located in karst areas account for a considerable proportion. In these tunnels, the surrounding rock is rich in water, which brings great water inrush risks to the construction and operation of the tunnels. In order to explore the mechanism of water and sand inrush in sandy dolomite areas under different water-rich conditions, it is urgent to carry out model tests on water and sand inrush in sandy dolomite, and analyze the mechanism of water and sand inrush and early warning information when the disaster occurs from the differences in the evolution laws of multiple field information such as surrounding rock stress and water inrush during the water inrush process. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology. The purpose is to provide a model test device suitable for simulating sudden water inrush in water-rich sandy dolomite. By simulating the differences in the evolution laws of multiple field information such as surrounding rock stress and water inrush volume during the water inrush process, the mechanism of sudden water and sand inrush and the early warning information when the disaster occurs are analyzed.

[0004] The present invention is achieved through the following technical solutions:

[0005] A model test device suitable for simulating sudden surge in water-rich sandy dolomite, comprising a test box with an opening at the top, a yellow clay layer provided inside the test box, and a surrounding rock layer and a gravel layer pre-buried in the yellow clay layer;

[0006] A pressure plate is provided at the opening of the test box, a water storage tank is provided on the pressure plate, a movable plate is provided in the water storage tank, and a water inlet pipe extending into the gravel layer is provided on the water storage tank;

[0007] It also includes a pressurizing component, which includes a first output shaft and a second output shaft. The first output shaft is used to be inserted into the water tank and push the movable plate to move, and the second output shaft is used to push the water tank to squeeze the pressurizing plate.

[0008] Furthermore, the surrounding rock layer is formed by mixing quartz stone, barite powder, vaseline heated in a water bath, and gypsum powder.

[0009] Furthermore, a support rod is provided on the top of the test box, a horizontal plate is provided on the support rod, and the pressure component is located on the horizontal plate.

[0010] Furthermore, the pressurizing assembly includes a cylinder body, a cylinder head, a piston and a cylinder bottom. The cylinder body passes through the cross plate, the cylinder bottom is fixed to the top of the cylinder body, the piston is located in the cylinder body, one end of the second output shaft is connected to the bottom of the piston, and the other end vertically passes through the cylinder head.

[0011] Furthermore, a first oil inlet hole is provided on the cylinder cover, and a second oil inlet hole is provided on the cylinder bottom.

[0012] Furthermore, a through hole having an inner diameter the same as that of the first output shaft is provided in the second output shaft, and the through hole passes through both ends of the second output shaft along the axial direction;

[0013] The first output shaft is located in the through hole;

[0014] The piston is also provided with a connecting hole communicated with the through hole.

[0015] Furthermore, the pressurizing assembly further comprises a movable cylinder whose outer diameter is consistent with the inner diameter of the cylinder body, the movable cylinder is located in the cylinder body, the outer diameter of the piston is consistent with the inner diameter of the movable cylinder, and the piston is located in the movable cylinder;

[0016] A groove is provided on the inner wall of the cylinder bottom facing the cylinder body, and a first telescopic member is provided in the groove. The movable end of the first telescopic member is provided with a connecting rod for connecting with the inner wall of the movable cylinder, and the first telescopic member is used to drive the movable cylinder to move axially along the second output shaft.

[0017] Furthermore, a limiting groove is provided on the inner wall of the movable cylinder, and an elastic member and a locking ball are provided in the limiting groove;

[0018] The circumferential side wall of the piston is further provided with a locking groove corresponding to the locking ball. When the locking groove on the piston is flush with the locking ball, the elastic member can push the locking ball into the locking groove to fix the piston in the movable cylinder;

[0019] The piston is further provided with a channel, one end of which is communicated with the locking groove, and the other end of which is communicated with the end surface of the piston away from the cylinder bottom.

[0020] Furthermore, a blocking block is provided at the end of the first telescopic member facing the piston, the outer diameter of the blocking block is consistent with the inner diameter of the connecting hole, and when the first telescopic member is stretched along the piston direction, the blocking block can be inserted into the connecting hole.

[0021] Furthermore, a movable rod is further provided in the first telescopic member, one end of the movable rod is fixedly connected to the movable end of the first telescopic member, and the other end thereof passes through the outside of the cylinder bottom;

[0022] A third oil inlet hole is provided inside the movable rod and is communicated with the interior of the first telescopic member;

[0023] The movable rod is further provided with a second telescopic member, which is sleeved on the end of the movable rod extending out of the bottom of the cylinder;

[0024] The first telescopic member and the second telescopic member are both bellows with a sealing structure.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0026] 1. The present invention utilizes the surrounding rock layer set in the simulation test box to simulate sandy dolomite, and simulates different seepage pressures by introducing different water pressures into the gravel layer. This allows the analysis of the mechanism of water and sand inrush and early warning information when disasters occur based on the differences in the evolution of multiple field information such as surrounding rock stress and water inrush volume during the water inrush process.

[0027] 2. The present invention utilizes a pressurizing component to not only adjust the initial ground stress of the simulation test, but also adjust the seepage pressure of the simulation test, thus meeting the needs of different simulation tests.

[0028] 3. The present invention utilizes the first telescopic member to adjust the position of the movable cylinder in the cylinder body, thereby adjusting the maximum displacement of the first output shaft and the second output shaft, further meeting the simulation requirements of different simulation tests, and utilizing the locking ball provided on the movable cylinder to limit the piston, ensuring that the second output shaft can maintain a stable initial ground stress, while facilitating the adjustment of the position of the first output shaft, thereby realizing the adjustment of the seepage pressure of the simulation test. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0030] Figure 1 This is the main view of the structure of the present invention;

[0031] Figure 2 It is a side view of the structure of the present invention;

[0032] Figure 3 This is a schematic diagram of the connection structure between the pressurizing component and the water storage tank of the present invention;

[0033] Figure 4 This is a schematic structural diagram of the pressurizing assembly and the water storage tank of the present invention in another state;

[0034] Figure 5 For the present invention Figure 3 The structural diagram of the enlarged part A in the middle;

[0035] Figure 6 For the present invention Figure 4 Schematic diagram of the structure after enlarging part B in the middle.

[0036] Markings and corresponding parts names in the accompanying drawings:

[0037] 1. Test chamber; 2. Water tank; 3. Support rod; 4. Cylinder bottom; 5. Pressurizing assembly; 6. Horizontal plate; 7. Water inlet pipe; 8. Gravel layer; 9. Surrounding rock layer; 10. Yellow clay layer; 11. Pressurizing plate; 12. Movable plate; 13. First output shaft; 14. First oil inlet hole; 15. Movable cylinder; 16. Cylinder body; 17. First telescopic member; 18. Movable rod; 19. Second telescopic member; 20. Second oil inlet hole; 21. Second output shaft; 22. Cylinder head; 23. Piston; 24. Connecting rod; 25. Third oil inlet hole; 26. Sealing block; 27. Channel; 28. Locking ball; 29. ​​Elastic member. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0039] Example

[0040] like Figures 1 to 6 As shown, the present invention includes a test box 1 with an opening on the top, a yellow clay layer 10 is provided inside the test box 1, and a surrounding rock layer 9 and a gravel layer 8 are pre-buried in the yellow clay layer 10; a pressure plate 11 is provided at the opening of the test box 1, a water tank 2 is provided on the pressure plate 11, a movable plate 12 is provided in the water tank 2, and a water inlet pipe 7 extending into the gravel layer 8 is provided on the water tank 2; and a pressure component 5 is also included, and the pressure component 5 includes a first output shaft 13 and a second output shaft 21, the first output shaft 13 is used to be inserted into the water tank 2 and push the movable plate 12 to move, and the second output shaft 21 is used to push the water tank 2 to squeeze the pressure plate 11.

[0041] In view of the existing technology, when constructing tunnels in sandy dolomite areas, in order to explore the mechanism of water and sand inrush in sandy dolomite areas under different water-rich conditions, this embodiment designs a model test of water and sand inrush in sandy dolomite, and analyzes the mechanism of water and sand inrush and the early warning information when a disaster occurs from the differences in the evolution laws of multiple field information such as surrounding rock stress and water gushing volume during the water inrush process. Among them, the surrounding rock layer 9 pre-buried in the yellow clay layer 10 is used to simulate the sandy dolomite, and the water storage tank is set to let water flow into the gravel layer 9, which can simulate the water-rich water storage structure near the sandy dolomite. At the same time, pressure sensors are pre-buried in the yellow clay layer 10 and the surrounding rock layer 9. In order to simulate the actual deep-buried ground stress, this simulation test device is provided with a pressurizing component 5. The set pressurizing component 5 can apply additional ground stress, that is, the set pressurizing component 5 drives the second transmission The output shaft 21 moves vertically to apply vertical pressure to the pressure plate 11. After the ground stress is loaded and the deformation of the yellow clay layer 10 is stabilized, the edges of the test box 1 and the yellow clay layer 10 are sealed with waterproof colloid. After the above steps are completed, the movable plate 12 in the water tank 2 is driven to move by the first output shaft 13, and the water stored in the water tank 2 is transported to the gravel layer 9 by the provided water inlet pipe 7, so as to replenish the water-rich water storage mechanism formed by the gravel layer 9. At the same time, the displacement of the first output shaft 13, that is, the displacement of the movable plate 12 in the water tank 2, can be used to adjust the water pressure in the gravel layer 9, thereby simulating different water-rich conditions in the tunnel. Finally, after the initial ground stress and seepage pressure of the simulated test device are balanced and stable, tunnel excavation is carried out. The test in this embodiment adopts the step valve excavation method of supporting while excavating.

[0042] The surrounding rock layer 9 is formed by mixing quartz stone, barite powder, vaseline heated in a water bath, and gypsum powder.

[0043] In this embodiment, in order to ensure that the surrounding rock layer 9 can simulate the sandified dolomite, a mixture of quartz stone, barite powder, vaseline heated in a water bath, and gypsum powder is fully stirred to achieve the purpose of simulating the sandified dolomite.

[0044] A support rod 3 is provided on the top of the test box 1 , a horizontal plate 6 is provided on the support rod 3 , and the pressurizing assembly 5 is located on the horizontal plate 6 .

[0045] In this embodiment, in order to fix the pressure assembly 5 on the upper side of the use box 1, a support rod 3 and a horizontal plate 6 are provided.

[0046] The pressurizing assembly 5 includes a cylinder body 16, a cylinder head 22, a piston 23 and a cylinder bottom 4. The cylinder body 16 passes through the cross plate 6. The cylinder bottom 4 is fixed to the top of the cylinder body 16. The piston 23 is located in the cylinder body 16. One end of the second output shaft 21 is connected to the bottom of the piston 23, and the other end vertically passes through the cylinder head 22.

[0047] In this embodiment, in order to enable the pressure component 5 to normally drive the movement of the second output shaft 21, a cylinder body 16, a cylinder head 22, a piston 23 and a cylinder bottom 4 are provided. The cylinder body 16, the cylinder head 22, the piston 23 and the cylinder bottom 4 are used to form a hydraulic cylinder structure. When the hydraulic oil medium is introduced into the cylinder body 16, the hydraulic oil can drive the piston 23 to move in the cylinder body 16, thereby driving the movement of the second output shaft 21 connected to the piston 23. During the movement, the second output shaft 21 can press down the water tank 2. Under the action of the water tank 2, the pressure plate 11 can be driven to press down the yellow clay layer 10 in the simulation box 1, thereby achieving the purpose of squeezing the yellow clay layer 10, and then adjusting the initial ground stress of the simulation test device.

[0048] The cylinder cover 22 is further provided with a first oil inlet hole 14 , and the cylinder bottom 4 is provided with a second oil inlet hole 20 .

[0049] In this embodiment, in order to ensure that the piston 23 can reciprocate in the cylinder body 22, a first oil inlet hole 14 and a second oil inlet hole 20 are provided. The first oil inlet hole 14 and the second oil inlet hole 20 are both connected to an external oil pump. The oil pump is controlled to introduce medium oil into the first oil inlet hole 14 or the second oil inlet hole 20, thereby controlling the movement direction of the piston 23 and realizing the extension and retraction of the second output shaft 21 in the vertical direction.

[0050] A through hole with the same inner diameter as the first output shaft 13 is provided in the second output shaft 21 , and the through hole runs axially through both ends of the second output shaft 21 ; the first output shaft 13 is located in the through hole; and a connecting hole communicating with the through hole is further provided on the piston 23 .

[0051] In order to adjust the position of the first output shaft 13 in this embodiment, a through hole for placing the first output shaft 13 is provided inside the second output shaft 21, and the through hole is connected to the connecting hole on the piston 23. Therefore, when the external oil pump delivers hydraulic oil medium to the cylinder body 22 through the second oil inlet hole 20 on the cylinder bottom 4, the hydraulic oil entering the cylinder body 22 enters the through hole of the second output shaft 21 through the provided connecting hole. The pressure of the hydraulic oil entering the cylinder body 22 gradually increases at any time, and finally, under the action of the hydraulic oil, the first output shaft 13 can be pushed out from the through hole of the second output shaft 21. Since a guide hole is provided on the top of the water storage tank 2, the guide hole The inner diameter of the guide hole is smaller than the outer diameter of the second output shaft 21 and is not smaller than the outer diameter of the first output shaft 13. This ensures that the first output shaft 13 can be inserted into the water tank 2 using the guide hole, while the second output shaft 21 cannot be inserted into the water tank 2. Therefore, the first output shaft 13 entering the water tank 2 pushes the movable plate 12 in the water tank 2. Since the cross-sectional size of the movable plate 12 is consistent with the cross-sectional size of the water tank 2, the first output shaft 13 can squeeze the water stored in the water tank 2 in the process of pushing the movable plate 12 to move, and squeeze the water in the water tank 2 into the water inlet pipe 7, thereby achieving the purpose of adjusting the simulated test osmotic pressure.

[0052] The pressurizing assembly 5 also includes a movable cylinder 15 whose outer diameter is consistent with the inner diameter of the cylinder body 16, and the movable cylinder 15 is located in the cylinder body 16. The outer diameter of the piston 23 is consistent with the inner diameter of the movable cylinder 15, and the piston 23 is located in the movable cylinder 15; the cylinder bottom 4 is provided with a groove on the inner wall facing the cylinder body 16, and a first telescopic member 17 is provided in the groove. The movable end of the first telescopic member 17 is provided with a connecting rod 24 for connecting to the inner wall of the movable cylinder 15, and the first telescopic member 17 is used to drive the movable cylinder 15 to move axially along the second output shaft 21.

[0053] In order to increase the stroke of the second output shaft 21 in this embodiment, a movable cylinder 15 and a first telescopic member 17 arranged on the cylinder bottom 4 are provided in the cylinder body 16. When it is necessary to adjust the position of the movable cylinder 15 in the cylinder body 16, the first telescopic member 17 is stretched in the cylinder body 16 toward the piston 23. During the stretching process, the first telescopic member 17 can drive the movable cylinder 15 to move in the cylinder body 16 by using the provided connecting rod 24, and adjust the length of the movable cylinder 15 extending in the cylinder body 16, thereby realizing the adjustment of the maximum displacement of the second output shaft 21 in the vertical direction, meeting the needs of different simulation tests.

[0054] A limiting groove is provided on the inner wall of the movable cylinder 15, and an elastic member 29 and a locking ball 28 are provided in the limiting groove; a locking groove corresponding to the locking ball 28 is also provided on the circumferential side wall of the piston 23. When the locking groove on the piston 23 is flush with the locking ball 28, the elastic member 29 can push the locking ball 28 into the locking groove, thereby fixing the piston 23 in the movable cylinder 15; a channel 27 is also provided on the piston 23, one end of which is connected to the locking groove, and the other end is connected to the end face of the piston 23 away from the cylinder bottom 4.

[0055] The movable cylinder 15 provided in this embodiment is used to be fixed with the piston 23, that is, when the driving piston 23 moves in the movable cylinder 15, and then drives the second output shaft 21 to press the water storage tank 2, the initial ground stress in the simulated test box 1 is adjusted by using the provided pressure plate 11, and after the initial ground stress stabilizes, the provided first telescopic member 17 is retracted to pull the movable cylinder 15 back, and when the locking ball 28 on the piston cylinder 15 moves to the same height as the locking groove on the piston 23, the provided elastic member 29 is used to quickly push the locking ball 28 into the locking groove of the piston 23, and the provided locking ball 28 is used to fix the piston 23 in the movable cylinder 15, so When the oil pump continues to deliver the medium oil into the cylinder 16 through the second oil inlet hole 20, the medium oil entering the cylinder 16 can no longer drive the movement of the piston 23, ensuring that the initial ground stress of the simulation test box 1 maintains a certain stability; at the same time, the hydraulic oil entering the cylinder 16 enters the through hole of the second output shaft 21 through the connecting hole on the piston 23, driving the movement of the first output shaft 13 in the through hole, forcing the first output shaft 13 to be inserted into the water tank 2, and pushing the movable plate 12 in the water tank 2 to squeeze the water in the water tank 2, and pressing the water tank 2 into the gravel layer 8 under the action of the water inlet pipe 7, thereby achieving the purpose of regulating the seepage pressure in the simulation test box 1.

[0056] On the one hand, the movable cylinder 15 provided in this embodiment can adjust the maximum displacement of the first output shaft 13 and the second output shaft 21 in the vertical direction, thereby meeting the simulation test requirements under the conditions. On the other hand, the provided piston cylinder 15 can be used to stably fix the piston 23 in the movable cylinder 15, thereby realizing the transformation of the pressure component 5 from driving the second output shaft 21 to driving the first output shaft 13, which is convenient for operation.

[0057] At the same time, after the simulation test is completed, the pressure medium oil is delivered to the movable cylinder 15 through the first oil inlet hole 14 set on the cylinder head 22. Since the piston 23 is fixed in the movable cylinder 15 under the action of the locking ball 28 at this time, the medium oil entering the movable cylinder 15 can only enter the channel 27. The medium oil entering the channel 27 is finally delivered to the locking groove of the piston 23, and pushes the locking ball 28 in the locking groove to retract into the limit groove of the movable cylinder 15, finally realizing the unlocking of the locking ball 28 and removing the restriction of the locking ball 28 on the piston 23. At this time, the medium oil entering the movable cylinder 15 through the first oil inlet hole 14 can smoothly push the movement of the piston 23, driving the second output shaft 21 to retract back.

[0058] A blocking block 26 is provided at the end of the first telescopic member 17 facing the piston 23 . The outer diameter of the blocking block 26 is consistent with the inner diameter of the connecting hole. When the first telescopic member 17 is stretched along the direction of the piston 23 , the blocking block 26 can be inserted into the connecting hole.

[0059] In this embodiment, in order to prevent the pressure medium oil from entering the connecting hole of the piston 23 when the pressure medium oil is transported into the cylinder body 16 by using the second oil inlet hole 20, thereby driving the first output shaft 13, a blocking block 26 is provided on the first telescopic member 17. The blocking block 26 is used to block the connecting hole on the piston 23, thereby preventing the hydraulic oil entering the cylinder body 16 from driving the first output shaft 13 to move.

[0060] A movable rod 18 is also provided inside the first telescopic member 17, one end of which is fixedly connected to the movable end of the first telescopic member 17, and the other end extends to the outside of the cylinder bottom 4; a third oil inlet hole 25 is provided inside the movable rod 18 and is connected to the inside of the first telescopic member 17; a second telescopic member 19 is also provided on the movable rod 18, and the second telescopic member 19 is sleeved on the end of the movable rod 18 extending outside the cylinder bottom 4; the first telescopic member 17 and the second telescopic member 19 are both bellows with a sealed structure.

[0061] Since the movable cylinder 15 is fixed in the cylinder body 16 by the first telescopic member 17, but the first telescopic member 17 is a bellows structure, which has a certain telescopic characteristic. Therefore, when the pressure medium is continuously transported into the cylinder body 16, the first telescopic member 17 is easily stretched, thereby failing to ensure that the movable cylinder 16 is stably fixed in the cylinder body 16. For this reason, a movable rod 18 and a second telescopic member 19 are provided in this embodiment. The third oil inlet hole 25 in the movable rod 18 and the second telescopic member 19 are respectively connected to an external oil pump through pipelines. When it is necessary to adjust the position of the movable cylinder 15 in the cylinder body 16, the oil pump is used to transport medium oil into the third oil inlet hole 25 of the movable rod 18. After the medium oil enters the first telescopic member 17, it forces the first telescopic member 17 to stretch and expand toward the piston 23, and pushes the movable cylinder 15 to move in the cylinder body 16. The first telescopic member 17 is stretched During the extension process, the movable rod 18 can be driven to move together. When the movable cylinder 15 moves to the appropriate position, the medium oil is introduced into the cylinder body 16 through the second oil inlet hole 20. The medium oil entering the cylinder body 16 drives the piston 23 to move, ensuring that the locking groove on the piston 23 and the locking ball 28 are at the same height, thereby stably fixing the piston 23 on the movable cylinder 15; then the medium oil is introduced into the second telescopic member 19, forcing the lower end of the second telescopic member 19 to move downward along the outer wall of the movable rod 18, and finally making the lower end of the second telescopic member 19 contact with the top of the cylinder bottom 4. At this time, since the second telescopic member 19 can no longer be stretched along its axial direction, the first telescopic member 17 can no longer continue to pull the movable rod 18 to move, and finally achieves the purpose of fixing the first telescopic member 17 in the cylinder body 16, that is, stably fixing the movable cylinder 15 in the cylinder body 16.

[0062] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A model test device suitable for simulating sudden surge in water-rich sandy dolomite, characterized in that: It comprises a test box (1) with an opening at the top, wherein a yellow clay layer (10) is provided inside the test box (1), and a surrounding rock layer (9) and a crushed stone layer (8) are pre-buried in the yellow clay layer (10); A pressure plate (11) is provided at the opening of the test box (1), a water tank (2) is provided on the pressure plate (11), a movable plate (12) is provided in the water tank (2), and a water inlet pipe (7) extending into the gravel layer (8) is provided on the water tank (2); The device further comprises a pressurizing assembly (5), wherein the pressurizing assembly (5) comprises a first output shaft (13) and a second output shaft (21), wherein the first output shaft (13) is used to be inserted into the water storage tank (2) and push the movable plate (12) to move, and the second output shaft (21) is used to push the water storage tank (2) to squeeze the pressurizing plate (11); The top of the test box (1) is provided with a support rod (3), the support rod (3) is provided with a horizontal plate (6), and the pressurizing assembly (5) is located on the horizontal plate (6); The pressurizing assembly (5) comprises a cylinder body (16), a cylinder head (22), a piston (23) and a cylinder bottom (4), wherein the cylinder body (16) passes through the transverse plate (6), the cylinder bottom (4) is fixed to the top of the cylinder body (16), the piston (23) is located in the cylinder body (16), and one end of the second output shaft (21) is connected to the bottom of the piston (23), and the other end vertically passes through the cylinder head (22); A through hole having an inner diameter identical to that of the first output shaft (13) is provided in the second output shaft (21), the through hole axially extending through both ends of the second output shaft (21); The first output shaft (13) is located in the through hole; The piston (23) is also provided with a connecting hole communicating with the through hole; The pressurizing assembly (5) further comprises a movable cylinder (15) having an outer diameter consistent with an inner diameter of the cylinder (16), the movable cylinder (15) being located in the cylinder (16), the outer diameter of the piston (23) being consistent with the inner diameter of the movable cylinder (15), and the piston (23) being located in the movable cylinder (15); A groove is provided on the inner wall of the cylinder bottom (4) facing the cylinder body (16), and a first telescopic member (17) is provided in the groove. A connecting rod (24) for connecting to the inner wall of the movable cylinder (15) is provided at the movable end of the first telescopic member (17). The first telescopic member (17) is used to drive the movable cylinder (15) to move axially along the second output shaft (21).

2. A model test device suitable for simulating sudden surge in water-rich sandy dolomite according to claim 1, characterized in that: The surrounding rock layer (9) is formed by mixing quartz stone, barite powder, vaseline heated in a water bath, and gypsum powder.

3. A model test device suitable for simulating sudden surge in water-rich sandy dolomite according to claim 1, characterized in that: A first oil inlet hole (14) is also provided on the cylinder cover (22), and a second oil inlet hole (20) is provided on the cylinder bottom (4).

4. A model test device suitable for simulating sudden surge in water-rich sandy dolomite according to claim 1, characterized in that: A limiting groove is provided on the inner wall of the movable cylinder (15), and an elastic member (29) and a locking ball (28) are provided in the limiting groove; The circumferential side wall of the piston (23) is further provided with a locking groove corresponding to the locking ball (28). When the locking groove on the piston (23) is flush with the locking ball (28), the elastic member (29) can push the locking ball (28) into the locking groove, thereby fixing the piston (23) in the movable cylinder (15); The piston (23) is further provided with a channel (27), one end of the channel (27) being in communication with the locking groove, and the other end being in communication with the end surface of the piston (23) in a direction away from the cylinder bottom (4).

5. A model test device suitable for simulating sudden surge in water-rich sandy dolomite according to claim 1, characterized in that: A blocking block (26) is provided at the end of the first telescopic member (17) facing the piston (23), the outer diameter of the blocking block (26) being consistent with the inner diameter of the connecting hole, and when the first telescopic member (17) is stretched in the direction of the piston (23), the blocking block (26) can be inserted into the connecting hole.

6. A model test device suitable for simulating sudden surge in water-rich sandy dolomite according to claim 1, characterized in that: A movable rod (18) is further provided in the first telescopic member (17), one end of the movable rod (18) is fixedly connected to the movable end of the first telescopic member (17), and the other end thereof passes through the outside of the cylinder bottom (4); A third oil inlet hole (25) is provided inside the movable rod (18) and is communicated with the inside of the first telescopic member (17); The movable rod (18) is further provided with a second telescopic member (19), and the second telescopic member (19) is sleeved on the end of the movable rod (18) extending out of the cylinder bottom (4); The first telescopic member (17) and the second telescopic member (19) are both bellows with a sealing structure.

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