A centrifugal model test device and test method for seepage failure of earth-rock dam

Abstract

The invention discloses a centrifugal model test device for seepage damage of earth-rock dam and a test method thereof. The device comprises an earth-rock dam model, wherein an upstream water head control box is arranged at an upstream side wall, and a toe wall model and a downstream water head control weir are arranged in sequence at a downstream side; a pore pressure sensor is fixed at the bottom of the downstream water head control weir; the aforementioned device is fixed as a whole in the earth-rock dam model box, the earth-rock dam model box is fixed in a closed model box through a bottom supporting structure, and the top of the closed model box is closed by a top cover; a water pump is fixed on one side of the top cover, and an upper circulating water pipe and a lower circulating water pipe are connected to the water pump, which are respectively passed into the bottom end of the closed model box and the upstream water head control box; a shooting device is fixed below the top cover, and the shooting range of the shooting device covers the earth-rock dam model; the closed model box is placed in a centrifuge basket platform, and the device and method of the invention can be used for seepage damage test research of various earth-rock dams, dam core walls, levees, tailings ponds, etc.

Description

Technical Field

[0001] The invention relates to a centrifugal model test device for seepage failure of earth-rock dams and a test method thereof, which are particularly suitable for the seepage failure test research of various earth-rock dams, dam anti-seepage bodies, embankment soil bodies, tailings ponds and the like. Background Art

[0002] my country is the country with the most reservoir dams in the world, with a total of more than 98,000 reservoir dams, of which earth-rock dams account for about 91.4%. In the past 50 years, my country's dam construction technology has continued to improve, and a large number of high earth-rock dam projects with a height of more than 100 meters have been built. It is difficult to control the deformation and seepage of high earth-rock dams, and diseases and safety accidents are prone to occur frequently. Therefore, it is urgent to improve the understanding and prediction level of the seepage failure mechanism and process of high earth-rock dams, and provide a scientific basis for taking effective safety control measures.

[0003] The high water head required for seepage research can be better achieved by using the supergravity field provided by the centrifuge. However, there are currently no relevant equipment and test methods for developing centrifugal models of seepage failure of earth-rock dams at home and abroad. Summary of the invention

[0004] The purpose of the invention is to provide a centrifugal model test device for seepage failure of earth-rock dam and a test method thereof.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0006] A centrifugal model test device for seepage damage of earth-rock dams, comprising an earth-rock dam model, wherein an upstream water head control box is arranged at the upstream side wall of the earth-rock dam model, an overflow hole is opened on the left side of the upstream water head control box, and a water permeable plate is arranged on the right side; a toe wall model and a downstream water head control weir are arranged in sequence at the downstream of the earth-rock dam model, water permeable holes are opened on the upstream and downstream surfaces of the dam body of the toe wall model, an electromagnetic valve is installed in the dam body, pipelines are installed before and after the electromagnetic valve, and the pipelines are respectively connected to the upstream and downstream water permeable holes; a pore pressure sensor is fixed at the bottom of the downstream water head control weir close to one side of the toe wall model;

[0007] The earth-rock dam model, the upstream water head control box, the toe wall model, and the downstream water head control weir structure are integrally arranged in the earth-rock dam model box. The earth-rock dam model box is fixed in the closed model box through the bottom support structure, and the top of the closed model box is closed by a top cover.

[0008] A water pump is fixed on one side of the top cover, and an upper circulating water pipe and a lower circulating water pipe are connected to the water pump. The upper circulating water pipe leads to the bottom end of the closed model box; the lower circulating water pipe leads to the upstream water head control box;

[0009] A shooting device is fixed under the top cover, and the shooting range of the shooting device covers the earth-rock dam model;

[0010] The closed model box is placed in the centrifuge hanging basket platform.

[0011] As a preferred implementation, the downstream water head control weir is a triangular weir or a rectangular weir.

[0012] As a preferred implementation, the toe wall model is made of impermeable material.

[0013] As a preferred embodiment, the bottom plate of the closed model box is inclined, and the horizontal height of the bottom plate near the upstream side of the earth-rock dam model is lower than that of the downstream side of the earth-rock dam model, so that the water flowing out from the downstream head control weir can be gathered to the other side.

[0014] As a preferred implementation, a pore pressure sensor is buried in the earth-rock dam model.

[0015] As a preferred embodiment, the support structure is a water-permeable structure so that the water in the closed model box is connected.

[0016] Another object of the present invention is to provide a method for conducting a centrifugal model test of seepage failure of an earth-rock dam using the above device, comprising the following steps:

[0017] (1) Start the centrifuge and accelerate it to the designed acceleration; turn on the power of the water pump and solenoid valve to continuously fill the upstream head control box with water to form seepage in the earth-rock dam model and the toe wall model until the data of each pore pressure sensor becomes stable;

[0018] (2) The electromagnetic valve is closed to simulate the failure of the toe wall drainage system, and the seepage damage characteristics of the dam slope are studied when the seepage line in the earth-rock dam model is forced to be raised; the position of the seepage line after the elevation is analyzed through the data of the pore pressure sensor, and the seepage damage of the dam slope is recorded by the camera (13).

[0019] (3) After the test, turn off the water pump and stop the centrifuge;

[0020] (4) Take out the centrifugal model test device for seepage failure of earth-rock dam and dismantle the earth-rock dam model.

[0021] Another object of the present invention is to provide an assembly method of the above device, comprising the following steps:

[0022] (1) Prepare a model toe wall, open water-permeable holes on the upstream and downstream surfaces of the model toe wall dam body, install a solenoid valve in the dam body, install pipelines before and after the solenoid valve, and connect the pipelines to the upstream and downstream water-permeable holes respectively;

[0023] (2) Fix the supporting structure on the bottom plate of the closed model box, and then fix the earth-rock dam model box on the supporting structure;

[0024] (3) Fix the downstream water head control weir equipped with the pore pressure sensor on the right edge of the earth-rock dam model box; fix the model toe wall near the downstream water head control weir;

[0025] (4) Fix the upstream water head control box to the left side wall of the earth-rock dam model box;

[0026] (5) Fill the earth-rock dam model between the upstream head control box and the model toe wall, and bury the pore pressure sensor in the earth-rock dam model according to research needs;

[0027] (6) Add circulating water into the closed model box, and the water level should not be higher than the bottom surface of the earth-rock dam model box;

[0028] (7) Fix the upper circulating water pipe, water pump, and lower circulating water pipe on the left side of the top cover, and install the camera on the right side of the top cover; then fix the top cover on the closed model box;

[0029] (8) Hoist the entire earth-rock dam seepage failure centrifugal model test device to the centrifuge basket platform; connect the pore pressure sensor to the centrifuge data acquisition system; connect the solenoid valve and water pump power lines to the centrifuge power slip ring; and connect the signal of the camera device to the control room.

[0030] As a preferred embodiment, the earth-rock dam model (5) is prepared by collecting earth and rock materials at the site to be tested, transporting them back to the laboratory for air drying and sieving, adding water according to the actual moisture content, mixing them evenly, and then filling them.

[0031] As a preferred implementation, step (5) further includes: embedding pore pressure sensors in the earth-rock dam model according to research needs.

[0032] By adopting the test device and the test method provided by the present invention, it is possible to carry out seepage damage test research on various earth-rock dams, dam anti-seepage bodies, embankment soil bodies, tailings ponds, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of a centrifugal model test device for seepage failure of earth-rock dams. DETAILED DESCRIPTION

[0034] Example 1

[0035] like Figure 1 The centrifugal model test device for seepage failure of earth-rock dam shown in the figure comprises an earth-rock dam model 5, an upstream water head control box 2 is arranged at the upstream side wall of the earth-rock dam model 5, an overflow hole is opened on the left side of the upstream water head control box 2, and a permeable plate is arranged on the right side; a toe wall model 4 and a downstream water head control weir 3 are arranged in sequence at the downstream of the earth-rock dam model 5; a pore pressure sensor 6 is fixed at the bottom of the downstream water head control weir 3 near the toe wall model 4;

[0036] The earth-rock dam model 5, the upstream water head control box 2, the toe wall model 4, and the downstream water head control weir 3 are integrally arranged in the earth-rock dam model box 1. The earth-rock dam model box 1 is fixed in the closed model box 7 through the bottom support structure 8, and the top of the closed model box 7 is closed by the top cover 12; the support structure 8 is a permeable structure;

[0037] A water pump 10 is fixed on one side of the top cover 12, and an upper circulating water pipe 9 and a lower circulating water pipe 11 are connected to the water pump 10. The upper circulating water pipe 9 leads to the bottom end of the closed model box 7; the lower circulating water pipe 11 leads to the upstream water head control box 2; a shooting device 13 is fixed below the top cover 12, and the shooting range of the shooting device covers the earth-rock dam model 5.

[0038] The closed model box 7 is placed in the centrifuge basket platform for centrifuge model testing.

[0039] The downstream water head control weir 3 described in this embodiment may be a triangular weir or a rectangular weir.

[0040] The toe wall model 4 is made of impermeable material, and water holes are opened on the upstream and downstream surfaces of the dam body of the toe wall model 4. A solenoid valve is installed in the dam body, and pipelines are installed before and after the solenoid valve, and the pipelines are respectively connected to the upstream and downstream water holes.

[0041] The bottom plate of the closed model box 7 is inclined, and the horizontal height of the bottom plate close to the upstream side of the earth-rock dam model 5 is lower than that of the downstream side of the earth-rock dam model 5 .

[0042] A pore pressure sensor can be buried in the earth-rock dam model 5 according to experimental needs.

[0043] Example 2

[0044] This embodiment specifically describes the assembly method of the device described in Embodiment 1, including the following steps:

[0045] (1) Collect soil and rock materials from the test site, transport them back to the laboratory for air drying and sieving, add water according to the actual moisture content, mix them evenly, and then fill them.

[0046] (2) Prepare a model toe wall 4, open water-permeable holes on the upstream and downstream surfaces of the dam body of the model toe wall 4, install a solenoid valve in the dam body, install pipelines before and after the solenoid valve, and connect the pipelines to the upstream and downstream water-permeable holes respectively;

[0047] (3) Fix the supporting structure 8 on the bottom plate of the closed model box 7, and then fix the earth-rock dam model box 1 on the supporting structure 8;

[0048] (4) Fix the downstream water head control weir 3 equipped with the pore pressure sensor to the right edge of the earth-rock dam model box 1; fix the model toe wall 4 near the downstream water head control weir 3;

[0049] (5) Fix the upstream water head control box 2 to the left side wall of the earth-rock dam model box;

[0050] (6) Building an earth-rock dam model 5 between the upstream water head control box 2 and the model toe wall 4; and burying a pore pressure sensor in the earth-rock dam model (5) according to research needs;

[0051] (7) Add circulating water into the closed model box 1, and the water level is not higher than the bottom surface of the earth-rock dam model box 5;

[0052] (8) Fix the upper circulating water pipe 9, the water pump 10, and the lower circulating water pipe 11 to the left side of the top cover 12, and install the camera 13 to the right side of the top cover 12; then fix the top cover 12 to the closed model box 1;

[0053] (9) Hoist the entire earth-rock dam seepage failure centrifugal model test device to the centrifuge basket platform; connect the pore pressure sensor to the centrifuge data acquisition system; connect the solenoid valve and water pump 10 power lines to the centrifuge power slip ring; and connect the signal of the shooting device to the control room.

[0054] Example 3

[0055] This embodiment specifically describes a method for conducting a centrifugal model test of seepage failure of an earth-rock dam using the device described in Embodiment 1, comprising the following steps:

[0056] (1) Start the centrifuge and accelerate it to the designed acceleration; turn on the water pump 10 and the solenoid valve power supply, and continuously fill the upstream water head control box 2 with water to form seepage in the earth-rock dam model 5 and the toe wall model 4 until the data of each pore pressure sensor reaches stability;

[0057] (2) The electromagnetic valve is closed to simulate the failure of the toe wall drainage system (the water pipe is closed and water cannot penetrate through the permeable holes), and the seepage damage characteristics of the dam slope are studied when the seepage line in the earth-rock dam model 5 is forced to be raised; the position of the seepage line after the elevation is analyzed through the data of the pore pressure sensor, and the seepage damage of the dam slope is recorded through the camera 13.

[0058] (3) After the test, turn off the water pump and stop the centrifuge;

[0059] (4) Take out the centrifugal model test device for seepage failure of earth-rock dam and dismantle the earth-rock dam model 5.

Claims

1. A centrifugal model test device for seepage failure of earth-rock dams, characterized in that: The invention comprises an earth-rock dam model (5), wherein an upstream water head control box (2) is provided at the upstream side wall of the earth-rock dam model (5), an overflow hole is provided on the left side of the upstream water head control box (2), and a water permeable plate is provided on the right side; a toe wall model (4) and a downstream water head control weir (3) are provided in sequence at the downstream side of the earth-rock dam model (5), water permeable holes are provided on the upstream and downstream surfaces of the dam body of the toe wall model (4), an electromagnetic valve is installed in the dam body, pipelines are installed before and after the electromagnetic valve, and the pipelines are respectively connected to the upstream and downstream water permeable holes; a pore pressure sensor (6) is fixed at the bottom of the downstream water head control weir (3) close to the toe wall model (4); The earth-rock dam model (5), the upstream water head control box (2), the toe wall model (4), and the downstream water head control weir (3) are integrally arranged in an earth-rock dam model box (1); the earth-rock dam model box (1) is fixed in a closed model box (7) via a bottom support structure (8); and the top of the closed model box (7) is closed via a top cover (12); A water pump (10) is fixed on one side of the top cover (12); an upper circulating water pipe (9) and a lower circulating water pipe (11) are connected to the water pump (10); the upper circulating water pipe (9) leads to the bottom end of the closed model box (7); and the lower circulating water pipe (11) leads to the upstream water head control box (2); A photographing device (13) is fixed below the top cover (12), and the photographing range of the photographing device covers the earth-rock dam model (5); The closed model box (7) is placed in the centrifuge hanging basket platform.

2. The device according to claim 1, characterized in that The downstream water head control weir (3) is a triangular weir or a rectangular weir.

3. The device according to claim 1, characterized in that The toe wall model (4) is made of impermeable material.

4. The device according to claim 1, characterized in that The bottom plate of the closed model box (7) is inclined, and the horizontal height of the bottom plate close to the upstream side of the earth-rock dam model (5) is lower than that of the downstream side of the earth-rock dam model (5).

5. The device according to claim 1, characterized in that A pore pressure sensor is embedded in the earth-rock dam model (5).

6. The device according to claim 1, characterized in that The supporting structure (8) is a water-permeable structure.

7. A method for conducting a centrifugal model test of seepage failure of earth-rock dams using the device according to any one of claims 1 to 6, characterized in that: The steps include: (1) Start the centrifuge and accelerate it to the designed acceleration; turn on the water pump (10) and the solenoid valve power supply, and continuously fill the upstream water head control box (2) with water to form seepage in the earth-rock dam model (5) and the toe wall model (4) until the data of each pore pressure sensor becomes stable; (2) Close the solenoid valve to simulate the failure of the toe wall drainage system and study the seepage damage characteristics of the dam slope when the internal seepage line of the earth-rock dam model (5) is forced to be raised; analyze the position of the raised seepage line through the data of the pore pressure sensor, and record the seepage damage of the dam slope through the camera (13); (3) After the test, turn off the water pump and stop the centrifuge; (4) Take out the centrifugal model test device for seepage failure of earth-rock dam and dismantle the earth-rock dam model (5).

8. The method for assembling the device according to any one of claims 1 to 6, characterized in that: The steps include: (1) preparing a model toe wall (4), wherein water permeable holes are provided on the upstream and downstream surfaces of the dam body of the model toe wall (4), a solenoid valve is installed in the dam body, and pipelines are installed before and after the solenoid valve, and the pipelines are respectively connected to the upstream and downstream water permeable holes; (2) fixing the supporting structure (8) on the bottom plate of the closed model box (7), and then fixing the earth-rock dam model box (1) on the supporting structure (8); (3) Fixing a downstream water head control weir (3) equipped with a pore pressure sensor on the right edge of the earth-rock dam model box (1); fixing the model toe wall (4) near the downstream water head control weir (3); (4) Fixing the upstream water head control box (2) to the left side wall of the earth-rock dam model box; (5) constructing an earth-rock dam model (5) between the upstream water head control box (2) and the model toe wall (4); (6) Adding circulating water into the closed model box (1) with the water level being no higher than the bottom surface of the earth-rock dam model box (5); (7) Fixing the upper circulating water pipe (9), the water pump (10), and the lower circulating water pipe (11) to the left side of the top cover (12), and installing the photographing device (13) to the right side of the top cover (12); and then fixing the top cover (12) to the closed model box (1); (8) The entire earth-rock dam seepage failure centrifugal model test device is hoisted onto the centrifuge basket platform; the pore pressure sensor is connected to the centrifuge data acquisition system; the power lines of the solenoid valve and water pump (10) are connected to the centrifuge power slip ring; and the signal of the camera device is connected to the control room.

9. The assembly method according to claim 8, characterized in that: The earth-rock dam model (5) is prepared by collecting earth and rock materials at the site to be tested, transporting them back to the laboratory for air drying and sieving, adding water according to the actual moisture content, mixing them evenly, and then filling them.

10. The assembly method according to claim 8, characterized in that: The step (5) further comprises: burying pore pressure sensors in the earth-rock dam model (5) according to research needs.

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