A comprehensive test platform for simulating diseases of shallow-buried tunnels

Abstract

The present invention discloses a comprehensive test platform for simulating shallow tunnel diseases, comprising: a test foundation pit, which is a dug cuboid foundation pit with an open upper part; a geotechnical similar material filled in the test foundation pit, and its upper surface is inclined; a tunnel similar model excavated in the middle of the geotechnical similar material and arranged along the length direction of the test foundation pit; a water pipe array at the bottom of the foundation pit, which includes multiple groups of water pipes laid side by side at the bottom of the test foundation pit, wherein its outlet end is used to introduce water into the test foundation pit and overflow into the geotechnical similar material; a water supply system connected to the inlet end of the water pipe array at the bottom of the foundation pit for supplying water to the water pipe array at the bottom of the foundation pit and adjusting the water level height on one side of the tunnel similar model in the test foundation pit; a drainage system for draining the water in the test foundation pit from the other side of the tunnel similar model. This comprehensive test platform realizes the consideration of the influence of rainfall infiltration, inclined groundwater level, eccentric load effect, and local surface load on the tunnel lining.

Description

Technical Field

[0001] The present invention belongs to the technical field of civil engineering, and particularly relates to a comprehensive test platform for simulating diseases of shallow tunnels. Background Technique

[0002] The geological conditions where tunnels are located are complex and variable. Ensuring the safe operation of in-service tunnels under complex geological conditions is an important requirement in national economic construction. And in accordance with the general principles of "adjusting measures to local conditions, comprehensive treatment, and environmental protection", diagnosing and treating diseases during the operation of tunnels in a timely manner is the key to ensuring the safe operation of tunnels. In order to better carry out research work on the occurrence mechanism of tunnel disasters, treatment measures, etc., it is necessary to build a comprehensive test platform for simulating tunnel diseases, and simulate various common tunnel diseases on the platform to carry out the research and development of treatment measures.

[0003] At present, the domestic underground engineering simulation test platforms mainly include: the traffic tunnel multi-functional engineering experimental system, the assembled disease tunnel test system, and the entity test tunnel system of the China Merchants Chongqing Communications Technology Research and Design Institute Co., Ltd.; the tunnel advanced geological prediction physical test system and the three-dimensional geomechanics model test platform of the Geotechnical and Structural Engineering Research Center of Shandong University.

[0004] However, the above existing simulation test platforms still have many deficiencies and cannot truly simulate tunnel diseases. Summary of the Invention

[0005] The purpose of the present invention is to provide a comprehensive test platform for simulating diseases of shallow tunnels, which realizes considering the influence of rainfall infiltration, inclined groundwater level, eccentric load effect, and local surface load on the tunnel lining.

[0006] The present invention adopts the following technical solutions: A comprehensive test platform for simulating diseases of shallow tunnels, including:

[0007] A test foundation pit, which is a cuboid foundation pit with an open upper part dug downwards;

[0008] A geotechnical similar material, filled in the test foundation pit, and its upper surface is inclined;

[0009] A tunnel similar model, excavated in the middle of the geotechnical similar material and arranged along the length direction of the test foundation pit;

[0010] An array of water pipes at the bottom of the foundation pit, including multiple groups of water pipes, laid side by side at the bottom of the test foundation pit. Among them, each group of water pipes has an inlet end and an outlet end, and its outlet end is used to introduce water into the test foundation pit and overflow into the geotechnical similar material;

[0011] A water supply system, connected to the inlet end of the array of water pipes at the bottom of the foundation pit, used to supply water to the array of water pipes at the bottom of the foundation pit, and adjust the water level height on one side of the tunnel similar model in the test foundation pit;

[0012] A drainage system drains the water in the test foundation pit from the other side of the tunnel similarity model and can discharge water at different water levels; the water supply system and the drainage system cooperate to supply and drain water to adjust the water level in the test foundation pit so that the tunnel similarity model is under the action of different water levels.

[0013] Furthermore, the water supply system includes: an intake well vertically excavated on one side of the test foundation pit and having the same depth as the test foundation pit; a water tank suspended in the intake well and capable of moving up and down vertically in the intake well, which is connected to the water inlet end of the water pipe array at the bottom of the foundation pit; the water tank is used to supply water to the water pipe array at the bottom of the foundation pit, and the vertical height of the water tank in the intake well controls the water level in the test foundation pit on the side of the intake well.

[0014] Furthermore, the drainage system includes: a drainage well vertically excavated on the other side of the test foundation pit and having a depth not less than that of the test foundation pit;

[0015] Drainage pipes, multiple in number, are all horizontally arranged between the test foundation pit and the drainage well. The multiple drainage pipes are arranged at intervals in the vertical direction, and both ends are connected to the test foundation pit and the drainage well. Among them, the end located in the drainage well is the water outlet. The water outlets of each drainage pipe are not opened simultaneously, and when the water outlet of a certain drainage pipe is opened, it is used to drain the water in the test foundation pit and make the water in the test foundation pit reach the height of the drainage pipe.

[0016] Furthermore, in the test foundation pit, the water levels on the sides of the drainage well and the intake well are not on the same horizontal plane.

[0017] Furthermore, at the bottom of the test foundation pit and below the similar material of the rock and soil mass, a permeable sand and gravel layer is laid, and the permeable sand and gravel layer is used for filtering the water in the test foundation pit.

[0018] Furthermore, a precipitation spray pipe array is arranged directly above the test foundation pit to simulate rainfall conditions such as rainfall, different rainfall times, and different rainfall patterns, and to precipitate water into the test foundation pit.

[0019] Furthermore, the precipitation spray pipe array includes multiple water pipes arranged in parallel, and a plurality of spray openings are spaced at intervals below each water pipe; each water pipe is connected to an external water source.

[0020] Furthermore, an open ground anchor reaction beam is arranged above the test foundation pit. The ground anchor reaction beam spans the upper opening of the test foundation pit and is connected to the similar material of the rock and soil mass through a vertically arranged jack. A loading plate is arranged at the bottom of the jack, and the jack shrinks itself to realize the load loading on the similar material of the soil body to simulate tunnel diseases caused by conditions such as the overlying soil layer of the tunnel, the surface external load outside the mountain body, and uneven settlement.

[0021] Furthermore, testing equipment is buried within the soil-like material and near the tunnel-like model.

[0022] Furthermore, a karst cave defect is buried within the soil-like material and near the tunnel-like model.

[0023] The beneficial effects of the present invention are as follows: 1. A rainfall simulation system is set up to simulate the damage of rainfall infiltration to the lining structure of shallow-buried tunnels. 2. Considering the harm of the change of the groundwater level to the lining, the adjustment ability to control the inclined water level line is realized. 3. Considering the eccentric load of the undulating terrain on the lining of shallow-buried tunnels. 4. Considering the influence of local surface loads on the lining of shallow-buried tunnels. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of a comprehensive test platform for simulating shallow-buried tunnel diseases;

[0025] Among them, 100 - test foundation pit; 200 - tap water; 201 - water tank; 202 - water inlet well with water tank hoist; 203 - permeable sand and gravel; 204 - water pipe array at the bottom of the foundation pit; 205 - water pipe array on the side of the foundation pit; 206 - open drain pipe; 207 - closed drain pipe; 208 - drainage well; 209 - drainage pump; 210 - water level line; 300 - precipitation spray pipe array; 400 - ground anchor reaction beam; 401 - jack; 402 - loading plate; 201 - tunnel-like model; 502 - soil-rock mass-like material; 504 - karst cave defect; 505 - testing equipment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The present invention will be described in detail below with reference to the drawings and specific embodiments.

[0027] A comprehensive test platform for simulating shallow-buried tunnel diseases of the present invention, as Figure 1 shown, includes: a test foundation pit 100, which is a dug rectangular foundation pit with an open upper part, and the bottom and periphery of the test foundation pit 100 are composed of cast-in-place reinforced concrete or steel-reinforced concrete. The soil-rock mass-like material 502 is filled in the test foundation pit 100, and its upper surface is inclined. Two or more types of soil-rock mass-like materials can be selected for the soil-rock mass-like material 502, specifically selected according to actual needs. For example, the soil-rock mass-like material simulating silt and the soil-rock mass-like material simulating clay. The soil-rock mass-like material simulating silt is located at the bottom within the test foundation pit 100, and the soil-rock mass-like material simulating clay is located above the soil-rock mass-like material simulating silt. The adjacent interface between the two is not flat, and can be set as undulating, that is, the upper part of the soil-rock mass-like material simulating silt at the lower part is not horizontally flat.

[0028] The tunnel-like model 201 is excavated in the middle of the soil-rock mass-like material 502 and is arranged along the length direction of the test foundation pit 100.

[0029] The similarity ratio of the above-mentioned tunnel similarity model 201 to the actual tunnel is about 1:3 to 5; the span of the tunnel similarity model 201 is about 2 to 4 m. Considering the principle of three times the tunnel diameter, the span of the foundation pit is greater than 5 to 7 times the span of the tunnel. The span of the test foundation pit 100 is about 15 m; the depth of the test foundation pit 100 is 3 to 5 times that of the tunnel similarity model.

[0030] The water pipe array 204 at the bottom of the foundation pit includes multiple groups of water pipes, which are laid side by side at the bottom of the test foundation pit 100. Each group of water pipes has an inlet end and an outlet end. The outlet end is used to introduce water into the test foundation pit 100 and overflow into the geotechnical material similarity material 502; each group of water pipes can be a serpentine pipe.

[0031] It includes: a water supply system, which is connected to the inlet end of the water pipe array 204 at the bottom of the foundation pit, used to supply water to the water pipe array 204 at the bottom of the foundation pit, and adjust the water level height on one side of the tunnel similarity model 201 in the test foundation pit 100; a drainage system, which drains the water in the test foundation pit 100 from the other side of the tunnel similarity model 201, and can discharge water under different water level lines.

[0032] The water supply system and the drainage system cooperate to supply water and drain water, which is used to adjust the water level in the test foundation pit 100 so that the tunnel similarity model 201 is under the action of different water levels.

[0033] The above-mentioned water supply system includes: a water inlet well 202, which is vertically excavated on one side of the test foundation pit 100, and its depth is the same as that of the test foundation pit 100; a water tank 201, which is suspended in the water inlet well 202 and can move up and down vertically in the water inlet well 202. It is connected to the inlet end of the water pipe array 204 at the bottom of the foundation pit; a hoist is provided at the mouth of the water inlet well 202 for lifting the water tank 201; the water tank 201 is used to supply water to the water pipe array 204 at the bottom of the foundation pit, and the vertical height of the water tank 201 in the water inlet well 202 controls the water level height in the test foundation pit 100 and on the side of the water inlet well 202. The water tank 201 is connected to the water source 200 through a pipeline. During actual construction, multiple water inlet wells 202 can be excavated at intervals, and a water tank 201 is arranged in each water inlet well 202, and the water tank 201 is connected to the corresponding water pipe.

[0034] The above drainage system includes: a drainage well 208, vertically excavated on the other side of the test foundation pit 100, and its depth is not less than the depth of the test foundation pit 100; a drainage pump 209 is arranged in the drainage well 208. A plurality of drain pipes 206, all horizontally arranged, are arranged between the test foundation pit 100 and the drainage well 208. The plurality of drain pipes 206 are arranged at intervals in the vertical direction, and both ends communicate with the test foundation pit 100 and the drainage well 208. Among them, the end located in the drainage well 208 is the water outlet. The water outlets of each drain pipe 206 are not opened simultaneously. When the water outlet of a certain drain pipe 206 is opened, it is used to drain the water in the test foundation pit 100 and make the water in the test foundation pit 100 at the height of the drain pipe 206. In the test foundation pit 100, the water levels on the sides of the drainage well 208 and the water inlet well 202 are not on the same horizontal plane, and an inclined water level line 210 is formed in the geotechnical similar material 502.

[0035] At the bottom of the test foundation pit 100 and below the geotechnical similar material 502, a permeable sand and gravel layer 203 is laid, and the permeable sand and gravel layer 203 is used to filter the water in the test foundation pit 100.

[0036] A precipitation spray pipe array 300 is arranged directly above the test foundation pit 100, which is used to simulate rainfall conditions such as rainfall, different rainfall times, and different rainfall patterns, and to precipitate water into the test foundation pit 100. The precipitation spray pipe array 300 includes a plurality of water pipes arranged in parallel, and a plurality of spray nozzles are spaced apart at the lower part of each water pipe; each water pipe is connected to an external water source.

[0037] An open ground anchor reaction beam 400 is arranged above the test foundation pit 100. The ground anchor reaction beam 400 spans the open upper part of the test foundation pit 100. It is connected to the geotechnical similar material through a vertically arranged jack 401. A loading plate 402 is arranged at the bottom of the jack 401. The jack 401 shrinks itself to realize the load loading on the soil similar material 503, so as to simulate tunnel diseases caused by conditions such as the upper soil layer of the tunnel, the surface external load outside the mountain body, and uneven settlement.

[0038] In the soil similar material 503 and near the tunnel similar model 201, testing devices 505 such as pressure cells and seepage meters are buried to measure the pressure or seepage water volume at the tunnel similar model 201. In the soil similar material 503 and near the tunnel similar model 201, a karst cave defect is buried.

Claims

1. A comprehensive test platform for simulating shallow-buried tunnel diseases, characterized in that, Comprising: A test foundation pit (100), which is a cuboid foundation pit with an open upper part dug downwards; A geotechnical similar material (502), filled in the test foundation pit (100), and its upper surface is inclined; A tunnel similar model (501), excavated in the middle of the geotechnical similar material (502) and arranged along the length direction of the test foundation pit (100); A water pipe array (204) at the bottom of the foundation pit, including multiple groups of water pipes, laid side by side at the bottom of the test foundation pit (100). Among them, each group of water pipes has an inlet end and an outlet end, and its outlet end is used to introduce water into the test foundation pit (100) and overflow into the geotechnical similar material (502); A water supply system, connected to the inlet end of the water pipe array (204) at the bottom of the foundation pit, used to supply water to the water pipe array (204) at the bottom of the foundation pit, and adjust the water level height on one side of the tunnel similar model (501) in the test foundation pit (100); A drainage system, draining the water in the test foundation pit (100) from the other side of the tunnel similar model (501), and can drain at different water levels; The water supply system and the drainage system cooperate to supply water and drain water, used to adjust the water level in the test foundation pit (100) so that the tunnel similar model (501) is under different water level effects; An open ground anchor reaction beam (400) is arranged on the upper part of the test foundation pit (100). The ground anchor reaction beam (400) straddles the open upper part of the test foundation pit (100), and is connected to the geotechnical similar material (502) through a vertically arranged jack (401). A loading plate (402) is arranged at the bottom of the jack (401). The jack (401) shrinks itself to realize the load loading on the geotechnical similar material (502) to simulate tunnel diseases caused by conditions such as the upper soil layer of the tunnel, the surface external load outside the mountain body, and uneven settlement; The drainage system includes: a drainage well (208), vertically excavated on the other side of the test foundation pit (100), and its depth is not less than the depth of the test foundation pit (100); Drainage pipes (206), which are multiple, all horizontally arranged between the test foundation pit (100) and the drainage well (208). The multiple drainage pipes (206) are arranged at intervals in the vertical direction, and both ends are connected to the test foundation pit (100) and the drainage well (208). Among them, the end located in the drainage well (208) is the water outlet. The water outlets of each drainage pipe (206) are not opened simultaneously, and when the water outlet of a certain drainage pipe (206) is opened, it is used to drain the water in the test foundation pit (100) and make the water in the test foundation pit (100) at the height of the drainage pipe (206); 2. The comprehensive test platform for simulating shallow-buried tunnel diseases according to claim 1, characterized in that, The water supply system includes: An inlet well (202), vertically excavated on one side of the test foundation pit (100), and its depth is the same as the depth of the test foundation pit (100); The water tank (201) is suspended in the water inlet well (202) and can move up and down vertically in the water inlet well (202). It is connected to the water inlet end of the water pipe array (204) at the bottom of the foundation pit. The water tank (201) is used to supply water to the water pipe array (204) at the bottom of the foundation pit, and the vertical height of the water tank (201) in the water inlet well (202) controls the water level height in the test foundation pit (100) and on the side of the water inlet well (202).

3. The comprehensive test platform for simulating shallow-buried tunnel diseases according to claim 2, characterized in that In the test foundation pit (100), the water levels on the side of the drainage well (208) and the water inlet well (202) are not on the same horizontal plane.

4. The integrated test platform for simulating diseases of shallow tunnels according to claim 3, characterized in that At the bottom of the test foundation pit (100) and below the similar material (502) of the rock and soil mass, a permeable sand and gravel layer (203) is laid. The permeable sand and gravel layer (203) is used to filter the water in the test foundation pit (100).

5. The comprehensive test platform for simulating shallow-buried tunnel diseases according to claim 4, characterized in that A precipitation spray pipe array (300) is arranged directly above the test foundation pit (100) and is used to simulate rainfall conditions with different rainfall times and different rainfall patterns, and to precipitate water into the test foundation pit (100).

6. The comprehensive test platform for simulating shallow-buried tunnel diseases according to claim 5, characterized in that, The precipitation spray pipe array (300) includes multiple pipes arranged in parallel. A plurality of spray openings are spaced at intervals at the lower part of each pipe. Each pipe is connected to an external water source.

7. The comprehensive test platform for simulating shallow-buried tunnel diseases according to claim 6, characterized in that, In the similar material (502) of the rock and soil mass and near the similar model (501) of the tunnel, a testing device (505) is buried.

8. The comprehensive test platform for simulating shallow-buried tunnel diseases according to claim 7, wherein, In the similar material (502) of the rock and soil mass and near the similar model (501) of the tunnel, a karst defect is buried.

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