CN203587317U - Artificial liquefaction flushing testing apparatus - Google Patents

Abstract

In the artificial liquefaction sand flushing test device provided by the utility model, the valve connected to the upper water tank is opened during the test to make the water flow on the surface of the sediment in the rectangular tank. Increase the flow rate and observe the state of the sediment surface. If the sediment just appears to be washed away by the water flow, establish the relationship between the amount of water required for a certain period of time and the amount of sand washed away; when using artificial vertical liquefaction technology to reduce the starting stress and When the flow rate is started, that is, when the valve connected to the upper water tank is opened, the lower pressure seepage pipe is opened, and a certain pressure is given. When the sediment just appears to be washed away by the water flow, the required water volume and sand flushing volume are established within a certain period of time. Relationship. Comparative verification using artificial vertical liquefaction technology can achieve high-efficiency impact on sedimentation and reduce water consumption under the condition of small flow, and provide a scientific basis for solving sedimentation problems in water conservancy construction.

Description

Artificial liquefaction sand flushing test device

technical field

The utility model relates to a test device for water conservancy projects, and is especially suitable for the test of artificial liquefaction sand flushing.

Background technique

As some large reservoirs and important rivers have serious sediment deposition in a short period of time after construction, which affects the water storage capacity of the reservoir and the flow capacity of the river, how to efficiently discharge sediment has become an important research topic at present. In recent years, in the practice of sand control, people have mainly adopted the comprehensive control measures of "blocking, discharging, adjusting, releasing, and digging", and also adopted measures such as "water regulation and sand regulation" and density flow sand discharge. In terms of theoretical analysis and practical application A number of important research results have been obtained, but the sediment transport capacity of the water flow is still low. For the fully consolidated soil, especially the muddy soil, the drag force when the water flow alone is less than the lifting force to start the sediment. Difficult, and the effect of flushing sand is not obvious, and consumes more water. At present, some water conservancy projects adopt the technology of "sand attacking by beaming water, sand washing by jet stream, and sand removal in high canals", which concentrates the amount of water to flow down and scour the river channel to deposit sediment. 1 ton of sand needs about ^40m3 of water, which shows that "water and sediment regulation" has not significantly improved the sediment transport capacity of water flow. According to the principle, whether it can effectively solve the current situation of more sand and less water under normal working conditions, and achieve the purpose of high-efficiency and water-saving sand flushing is a problem worthy of research.

The utility model designs an artificial sand flushing liquefaction test device, uses the principle of artificial vertical liquefaction technology to reduce the starting stress and starting flow velocity of sediment, and researches that high-efficiency sand flushing can be realized even in the case of low flow rate and small flow rate, which greatly saves sand flushing Use water to provide a basis for efficient sand removal in water conservancy projects.

Contents of the invention

The purpose of the utility model is: through the test device provided, verify the assumption that the artificial vertical liquefaction technology improves the efficiency of sand flushing, and provide scientific basis for the efficient sand discharge of water conservancy projects.

The purpose of this utility model is achieved like this: artificial liquefaction sand washing test device, the device is made up of water tank 1, pressure seepage pipe 2, upper water tank 3, lower water tank 4, permeable partition 5, multistage grit chamber 6, water pump 7, Valve 8, flow valve 9, pressurization equipment 10, pressure water tank 11, pressure gauge 12, pressure regulation water injection valve 13 constitute; Pressure gauge 12, pressure regulation water injection valve 13 and Connect the pipeline of the pressurizing equipment 10; the upper water tank 3 is set on the upper left side in the water tank 1, and the lower water tank 4 is set on the right side, wherein a permeable partition 5 is set at the lower left side of the lower water tank 4; between the lower water tank 4 and the upper water tank 3 Between them, a transverse diaphragm is fixed in the middle of the water tank 1, and a pressure seepage pipe 2 is arranged on it, wherein a flow valve 9 is installed on the pipeline connecting the pressure seepage pipe 2 and the pressure water tank 11; Sedimentation tanks 6 are evenly distributed between the permeable partitions 5, and vertical partitions are arranged on the sedimentation tanks 6, wherein the vertical partitions are respectively fixed on the bottom surface of the water tank 1; valve 8.

The working principle of the utility model: the traditional idea is that the seepage deformation of the soil caused by the seepage force is a kind of harm to the project. Conventionally, various methods are always used to prevent or control it, and little consideration is given to how to use the seepage deformation of the soil to deal with the project However, this device breaks the traditional concept. By artificially buried pipes for pressurization, ultra-static pore water pressure is generated inside the sediment, so that the sediment particles are liquefied and suspended, resulting in a decrease in effective gravity, and finally The initial shear stress and initial flow velocity of sediment are reduced, and high-efficiency sand flushing can be realized even in the case of low flow velocity and small flow rate, and the sand transport capacity of water flow can be improved.

The utility model provides the best experimental platform for the test of the sand transport capacity, and obtains the relationship between the required flow velocity and flow rate and the amount of sediment flushed out when the sediment in the unopened lower pressure seepage pipe is taken away by the water flow; When the sediment in the lower pressure seepage pipe is taken away by the water flow, the relationship between the required flow velocity and flow rate and the amount of sediment washed out; when the upper flow velocity is constant, when the sediment is taken away, the pressure required by the lower pressure seepage pipe and the amount of deposited sediment The relationship between the thickness; when the pressure provided by the lower pressure seepage pipe is constant, the relationship between the sediment deposition thickness and the required flow rate; this quantitative index has important application value and demonstrates technological progress.

Description of drawings

The utility model is further described in conjunction with the accompanying drawings.

Accompanying drawing is the structural representation of this test device;

As shown in the figure: 1-water tank, 2-pressure seepage pipe, 3-upper water tank, 4-lower water tank, 5-permeable partition, 6-multi-stage grit chamber, 7-water pump, 8-valve, 9-flow Valve, 10-pressurization equipment, 11-pressure water tank, 12-pressure gauge, 13-pressure regulating water injection valve.

Detailed ways

The utility model is further described in conjunction with the embodiments.

Example

Device design: On the top of the pressure water tank of the test device, a pressure gauge, a pressure regulating water injection valve and a pipeline connected to the pressurized equipment are installed; The lower part of the left side is provided with a permeable partition; between the lower water tank and the upper water tank, a horizontal partition is fixed in the middle of the tank, and a pressure seepage pipe is arranged on it, and a flow valve is installed on the pipeline connecting the pressure seepage pipe and the pressure water tank; The sedimentation tank is evenly distributed between the water pump and the permeable partition at the lower part of the tank, and vertical partitions are set on the sedimentation tank, and the vertical partitions are respectively fixed on the bottom of the tank; the external pipeline connecting the water pump and the upper tank is installed valve.

The tank of the device is rectangular.

Stepped vertical partitions are evenly distributed in the sedimentation tank of the device.

Implementation points:

1) Upper water tank: Provide a stable water source for the upstream of the sediment in the tank; there are uniform round holes on the right side of the water tank to facilitate the flow of water evenly into the lower sediment;

2) Lower water tank: used to store the water and sediment washed out of the rectangular tank, and at the same time realize the deposition of sediment in the tank;

3) Permeable partition: reduce the sediment in the lower water tank from flowing into the lower water delivery tank, and realize the initial filtration of sediment;

4) Multi-stage desilting tank: It is composed of multi-stage baffles whose height gradually decreases, and realizes the blocking effect on the sediment step by step to achieve the effect of further filtering;

5) Water pump: After the water is purified through the cascade sedimentation tank, the water is pumped to the upper water tank to realize the recycling of water resources;

6) Valve: used to control the size of the water flow for sand flushing on the surface of the sediment;

7) Flow valve: used to control the water output in the pressure seepage pipe;

8) Pressurization equipment (high slope pressure pool or pressure water tank with air compressor): provide the pressure water head required for the test to the osmotic pressure buried pipe;

9) Pressure water tank: used to provide a stable pressure source for the pressure seepage pipe;

10) Pressure gauge: used to display the pressure head;

11) Pressure regulating valve and water injection valve: used to adjust the size of the pressure head and inject water into the pressure water tank.

Specific operation steps:

1) Set up a rectangular water tank with a diaphragm inside, lay pressure seepage pipes on the diaphragm, and then lay sediment on the pressure seepage pipes, the first laying thickness is 5cm, so that it can be deposited in water, according to the needs of experimental research , gradually adding the thickness of the sediment.

2) Then open the valve on the upper water tank to control the flow of water to consolidate the sand drainage, observe the pore water change of the sand, and observe the settlement deformation of the sand surface at the same time, select six points for observation, and measure it every 1 hour. When the three consecutive deformations are not greater than 2mm, it is preliminarily determined that the excess pore water stress inside the soil is zero, the surface settlement tends to be stable, and the sediment has basically consolidated.

3) Open the water injection valve to inject water into the pressure water tank and then close it, then turn on the switch of the air compressor to add pressure, and make the pressure of the pressure water tank reach a stable value through the regulating valve, which is 0.5KPa. At this time, the pressure gauge can Display the pressure head, open the flow valve, control the water output in the pressure seepage pipe, make the bottom of the sediment form a pressure water source, thereby generating ultra-static pore water pressure; if the pressure provided is large enough, the sediment particles will be liquefied and suspended. At this time, the phenomenon of "boiling sand" appears above the buried pipe;

4) Add water to the water tank upwards so that the water level in the water tank is 10cm, and at the same time make the water flow form a stable flow state in the rectangular tank; start the water pump and control the size of the water flow by adjusting the flow valve so that the liquefied sediment particles are just flowed by the water flow Wash away, after a period of stabilization, measure the flow velocity of the sediment particles when they start, and calculate the relationship between the amount of sand washed and water consumption within 2 hours;

5) Close the pressure seepage pipe at the lower part, and do not provide the lower pressure water source for the sediment. Under the original flow rate, the sediment cannot be washed away; gradually increase the flow rate of the upper water tank, and when the sediment particles just move with the water flow, Stop increasing the flow, and after a period of stabilization, measure the flow velocity of the sediment particles when they start, and at the same time calculate the relationship between the amount of sand washing and water consumption within 2 hours; compare them, and analyze that after the action of the pressure seepage pipe, the impact will be certain Water-saving effect of sediment content.

Material of the device:

The materials of the rectangular water tank, the water tank and the dividing plate made by the utility model are all organic glass plates, which are cut and bonded according to specific dimensions.

Claims (3)

1. The artificial liquefaction sand flushing test device is characterized in that the device consists of a water tank (1), a pressure seepage pipe (2), an upper water tank (3), a lower water tank (4), a permeable partition (5), and a multi-stage sedimentation Pool (6), water pump (7), valve (8), flow valve (9), pressurization equipment (10), pressure water tank (11), pressure gauge (12), pressure regulating water injection valve (13); On the top of the pressure water tank (11) of the test device, a pressure gauge (12), a pressure regulating water injection valve (13) and a pipeline connected to the pressurizing equipment (10) are installed; For the water tank (3), the lower water tank (4) is set on the right side, wherein a water-permeable partition (5) is set on the left lower part of the lower water tank (4); between the lower water tank (4) and the upper water tank (3), in the water tank (1 ) is fixed with a diaphragm in the middle, and a pressure seepage pipe (2) is arranged on it, and a flow valve (9) is installed on the pipeline connecting the pressure seepage pipe (2) and the pressure water tank (11); The sedimentation tank (6) is evenly distributed between the set water pump (7) and the permeable partition (5), and vertical partitions are set on the sedimentation tank (6), wherein the vertical partitions are respectively fixed on the sides of the water tank (1) Bottom surface; valve (8) is installed on the external pipeline connecting water pump (7) and upper water tank (3). 2. The device according to claim 1, characterized in that the water tank (1) of the device is rectangular. 3. The device according to claim 1, characterized in that: the settling tank (6) of the device is evenly distributed with stepped vertical partitions.

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