CN108149644B - A hydraulic automatic silt reduction system and construction method in front of a rolling dam - Google Patents

Abstract

The invention discloses an automatic hydraulic silt reducing system in front of a rolling dam and a construction method. The silt reducing system comprises a shore water diversion channel, a water collecting tank, a sand washing pipe and a fixed pier. The water collecting tank is positioned at the bottom of the water diversion channel, the tank top is provided with a water inlet hole and a vent hole, and the tank side is connected with the sand washing pipe. The sand washing pipe inlet section is an inverted U-shaped pipe, the slope section is provided with a flat pressing pipe, and the pipe body of the river section fixed by the fixed pier is provided with a sand washing nozzle. The water body continuously enters the water collecting tank by flowing automatically through the water inlet channel, when the water level in the water tank reaches the top of the U-shaped pipe, the siphon phenomenon is automatically induced, then the water body is continuously sprayed from the sand washing spray head at a high flow speed, local turbulence is formed in front of the dam to prevent sediment of mud and sand, and the mud and sand are driven to flow into a downstream river channel through the sand discharging hole of the dam body. The construction method comprises the following steps: 1. constructing a water channel, a water collecting tank and a fixed pier; 2. a prefabricated member; 3. and (5) field sectional installation. The invention automatically forms jet flow and turbulent flow to continuously drive sand by utilizing the siphon principle, and has the characteristics of good silt reduction effect, convenient operation and maintenance, ecological environment protection and the like.

Description

A hydraulic automatic silt reduction system and construction method in front of a rolling dam

technical field

The invention belongs to the technical field of hydraulic sand removal, in particular to a hydraulic automatic silt reduction system and construction method in front of a rolling water dam.

Background technique

Rolling dams have been widely used in the comprehensive management of small and medium watersheds in mountainous areas and have achieved good social benefits. However, during the operation of the rolling dam, the flow rate of the water flow is reduced due to the dam body’s retention, and the sediment in the water gradually deposits in front of the dam, which often leads to serious consequences such as extensive siltation in front of the dam, reduction in storage capacity, and weakening or even disappearance of the river’s ecological flow regulation function.

At present, there are two main methods for reducing and dredging silt in front of rolling dams in mountainous areas: first, changing the structural type of rolling dams. The main research and patented technologies involved in this method are as follows: (1) Set up a discharge and sand discharge gate for sand discharge (Huang Jialin, Fu Xuefeng. Design and application of rolling dams for water intake supporting projects of thermal power plants[J]. Jiangxi Coal Science and Technology , 2014, (1): 60-63); (2) In the middle of the rolling dam, a sand-washing bottom hole consisting of a gate well section and a box-shaped culvert section (Hou Bo. Talking about the frontal sediment discharge of the head of Kalanguer Application of side water diversion method [J]. Shaanxi Water Conservancy, 2014, (S1): 14-15); (3) In the rolling gate composed of wooden pole triangular brake frame, wooden pole parallel series gate and plastic sheet parallel series apron In the dam, the space between the gate frames is reserved for setting the sand discharge outlet (rolling water dam equipment. Application number: 200410033140.5; 2004.11.10). (4) Using the principle of curved water flow, build an arc-shaped rolling dam for sand washing (an arc-shaped rolling dam that can automatically flush sand and reduce silt and its operating method. Application number: 201710148388.3; 2017.03.14). Second, manual or mechanical dredging. Regularly dredge the mud and sand accumulated in front of the rolling dam by manpower or machinery (forklifts, excavators and high-pressure nozzles, etc.).

The above-mentioned silt reduction methods all have certain silt reduction effects, but there are also some deficiencies. The first type of method requires a large modification of the dam body, and the silt reduction effect on the silt and sand in the far area in front of the dam is not good. The second type of method needs to deal with a large amount of dredged mud and sand, which has many links, high cost and easy to cause soil erosion.

Contents of the invention

Aiming at the existing technical problems in reducing the sedimentation in front of rolling water dams in mountainous areas, the invention uses the principle of siphon to automatically form jet flow and turbulent flow to continuously drive sand, and provides a hydraulic automatic sedimentation reduction system with good silt reduction effect, convenient operation and maintenance, and eco-environmental protection and construction methods.

In order to achieve the above object, the technical scheme adopted by the present invention is as follows.

The invention discloses a hydraulic automatic silt reduction system and a construction method in front of a rolling dam. The silt reduction system includes a bank diversion channel, a sump, a sand washing pipe and a fixed pier. The water collection tank is located at the bottom of the water diversion canal, the top of the tank is provided with water inlet holes and ventilation holes, and the side of the tank is connected with a sand washing pipe. The inlet section of the sand washing pipe is an inverted U-shaped pipe, the slope section is provided with a flat pressure pipe, and the pipe body of the river section fixed by a fixed pier is provided with a sand washing nozzle.

Further, in the diversion canal, the head of the canal adopts no dam diversion; the tail of the canal is provided with a discharge hole and is located on the bank downstream of the rolling dam; the width is 0.3-2m, and the depth is 0.3-2m.

Further, the sump and sand washing pipes are arranged from 2 to 3 m in front of the rolling dam, and are arranged upstream along the centerline of the river at intervals of 3 to 10 m until the end of the affected area in front of the rolling dam.

Further, the shape of the sump is square; the depth is 0.5~2m, the length×width is 0.5×0.5~2m×2m; the top plate is a stainless steel flap, and a water inlet hole with a diameter of 0.05~0.1m is set at the center, and The elevation is consistent with the bottom of the channel; the elevation of the floor is 1~3m higher than the normal water level of the river.

Further, the diameter of the sand washing pipe is 0.2-1m; the elevation of the water inlet is 0.1-0.2m higher than the elevation of the bottom plate of the sump.

Further, the elevation of the connection point between the flushing pressure pipe and the sand flushing pipe is located between the normal water level of the river and the elevation of the sump bottom.

Further, the sand washing nozzle is divided into a one-way nozzle and a two-way nozzle; the one-way nozzle is perpendicular to the sand washing pipe on the horizontal plane toward the downstream; Vertical on the horizontal plane; one-way nozzles and two-way nozzles are arranged at intervals on the sand washing pipe; the diameter of the nozzle is 0.02~0.1m; the shape of the nozzle is conical; the distance between adjacent nozzles is 0.5~1.5m.

Further, the fixed pier adopts a reinforced concrete structure, and the elevation of the top is consistent with the elevation of the river bed.

Further, the construction method is as follows: 1. Clean up the foundation, build a diversion channel and a sump on the side of the river bank; build a fixed pier in the river bed; 2. Prefabricate sand washing pipes (inlet section, slope section and river section pipelines), sand washing nozzles, sump roof and other components; 3. Transport the prefabricated components to the site for installation, and the parts are connected by threads or flanges.

Compared with the prior art, the beneficial effects of the present invention are as follows.

1. Good silt reduction effect. On the one hand, the water continuously flows into the sump through the diversion channel. When the water level in the tank reaches the top of the U-shaped pipe, the siphon phenomenon is automatically induced, and then it is continuously sprayed from the sand washing nozzle at a relatively large flow rate, forming a local turbulent flow in front of the dam to prevent sediment deposition. The mud and sand are driven to flow into the downstream channel through the sand discharge holes of the dam body. On the other hand, the sump and sand washing pipes are arranged starting from 2-3m in front of the rolling dam, and are arranged upstream along the centerline of the river at intervals of 3-10m until the end of the area in front of the rolling dam. Sediment deposition in the area in front of the dam.

2. Easy operation and maintenance. On the one hand, the system does not need special personnel to manage during operation, which is convenient for operation and management; on the other hand, the devices in the system are assembled with prefabricated components. If there is a failure, only the problematic parts can be replaced, which is convenient for maintenance.

3. Ecological and environmental protection. On the one hand, the system uses the principle of siphon to operate automatically, without providing additional power to consume energy and affect the environment; on the other hand, the system reduces the sedimentation in front of the rolling dam and ensures its function of regulating the ecological flow of the river. The ecological environment in the basin has played a positive role.

Description of drawings

Fig. 1 is the overall schematic diagram of the structure of the present invention.

Figure 2 is a sectional view of the present invention.

Fig. 3 is a schematic diagram of the sand flushing nozzle (one-way and two-way) of the present invention.

In the figure: 1—diversion channel; 2—water collection tank; 3—ventilation hole; 4—inlet hole; 5—sand washing pipe; 6—flat pressure pipe; 7—sand washing nozzle; 8—fixed pier; 9— rolling dam.

Detailed ways

The technical solutions of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Example.

The invention discloses a hydraulic automatic silt reduction system and a construction method in front of a rolling dam. The silt reduction system includes a bank diversion channel 1 , a sump 2 , a sand washing pipe 5 and a fixed pier 8 . The sump 2 is located at the bottom of the water diversion canal 1, and the vent hole 3 (to balance the pressure of the sump 2 and the outside atmosphere) and the water inlet 4 are arranged on the top of the sump, and the sand washing pipe 5 is connected to the side of the sump. The inlet section of the sand washing pipe 5 is an inverted U-shaped pipe, the flat pressure pipe 6 is arranged on the slope section, and the sand washing nozzle 7 is arranged on the pipe body of the river section fixed by the fixed pier 8 .

Further, in the diversion canal 1, the head of the canal adopts no dam diversion; the tail of the canal is provided with a discharge hole and is located downstream of the rolling dam; the width is 0.3-2m (preferably 0.5m), and the depth is 0.3-2m (preferably 0.5m). Ensure that the system draws water from the upstream river, and at the same time, the excess water is discharged back to the river through the discharge hole to avoid waste.

Further, the sump 2 and the sand washing pipe 5 are arranged from 2 to 3 m (preferably 2 m) in front of the rolling dam, and are arranged upstream along the centerline of the river at intervals of 3 to 10 m (preferably 6 m), until The end of the affected area in front of the rolling dam. Reduced the silt deposition in the area in front of the entire rolling dam.

Further, the shape of the sump 2 is square, which is convenient for construction; the depth is 0.5~2m (preferably 1m), the length×width is 0.5×0.5~2m×2m (preferably 1m×1m), to ensure a certain water storage capacity; the roof It is a stainless steel flap, and a water inlet hole with a diameter of 0.05~0.1m (preferably 0.01m) is set at the center, and the elevation is consistent with the elevation of the canal bottom, so that the water in the canal can enter the sump 2, and the flow rate can be controlled at the same time, so as to avoid no leakage in the downstream channels. Water; the elevation of the bottom plate is 1~3m (preferably 2m) higher than the normal water level of the river, so as to ensure that the water flow has a relatively large flow velocity and impact force when it is ejected from the sand washing nozzle 7.

Further, the diameter of the sand washing pipe 5 is 0.2~1m (preferably 0.5m); the elevation of the water inlet is 0.1~0.2m (preferably 0.15m) higher than the elevation of the bottom plate of the sump, so as to ensure that the water flow can enter the sand washing pipe 5 smoothly through the siphon.

Further, the elevation of the connection point between the flushing and flattening pipe 6 and the sand flushing pipe 5 is located between the normal water level of the river and the elevation of the bottom of the sump 2, so as to ensure that the air pressure on the slope section of the sand flushing pipe 5 is consistent with the outside world, thereby successfully inducing the siphon phenomenon .

Further, the sand washing nozzle 7 is divided into a one-way nozzle and a two-way nozzle; the one-way nozzle is perpendicular to the sand washing pipe 5 on the horizontal plane toward the downstream; The line is perpendicular to the sand washing pipe 5 on the horizontal plane; the one-way nozzle and the two-way nozzle are arranged at intervals on the sand washing pipe 5; the diameter of the nozzle is 0.02~0.1m (preferably 0.05m); the shape of the nozzle is conical; The spacing is 0.5~1.5m (preferably 1m). The one-way nozzles face downstream to form the impact mainstream area, while the two-way nozzles arranged at intervals strengthen the impact from both sides.

Further, the fixed pier 8 adopts a reinforced concrete structure, and the elevation of the top is consistent with the elevation of the river bed. Ensure that the structure does not hinder the riverbed.

Further, the construction method is as follows: 1. Clean up the foundation, build a diversion channel 1 and a sump 2 on one side of the river bank; build a fixed pier 8 in the river bed; 2. Prefabricate the sand washing pipe 5 (inlet section , Slope section and river section pipeline), sand washing nozzle 7, water collection tank 2 roof and other components; 3. The factory prefabricated components are transported to the site for installation, and the parts are connected by threads or flanges.

Claims (6)

1. The hydraulic automatic silt reducing system in front of the rolling dam is characterized by comprising a shore water channel, a water collecting tank, a sand washing pipe and a fixed pier; the water collecting tank is positioned at the bottom of the water diversion channel, a water inlet hole and a vent hole are formed in the top of the water collecting tank, and the side of the water collecting tank is connected with the sand washing pipe; the sand washing pipe inlet section is an inverted U-shaped pipe, the slope section is provided with a flat pressing pipe, and the pipe body of the river section fixed by the fixed pier is provided with a sand washing nozzle.

2. The hydraulic automatic silt reducing system before a rolling dam according to claim 1, wherein the water collecting tank and the sand washing pipe are arranged from 2m to 3m in front of the rolling dam and are sequentially arranged at intervals of 3m to 10m up to the tail end of the area in front of the rolling dam along the center line of a river channel.

3. A front hydraulic automatic silt reducing system according to claim 1, wherein said water collecting tank is square in shape; the depth is 0.5-2 m, and the length multiplied by the width is 0.5 multiplied by 0.5-2 m multiplied by 2m; the top plate is a stainless steel turning plate, a water inlet hole with the diameter of 0.05-0.1 m is arranged at the center position, and the elevation is consistent with the bottom of the canal; the elevation of the bottom plate is 1-3 m higher than the normal water level of the river channel.

4. The automatic hydraulic silt reducing system before a rolling dam according to claim 1, wherein the diameter of the sand washing pipe is 0.2-1 m; the elevation of the water inlet is 0.1-0.2 m higher than the elevation of the water collecting tank bottom plate.

5. The hydraulic automatic silt reducing system before a rolling dam according to claim 1, wherein the sand washing spray head is divided into a one-way spray head and a two-way spray head; the unidirectional spray head faces downstream and is vertical to the sand washing pipe on the horizontal plane; the included angle of the bidirectional spray nozzle is 15-45 degrees, the bidirectional spray nozzle faces downstream, and the central line is vertical to the sand washing pipe on the horizontal plane; the unidirectional spray heads and the bidirectional spray heads are arranged on the sand washing pipe at intervals; the diameter of the spray pipe is 0.02-0.1 m; the nozzle is conical in shape; the distance between adjacent spray heads is 0.5-1.5 m.

6. A method of constructing a hydraulic automatic silt reducing system in front of a rolling dam according to any one of claims 1 to 5, characterized in that the method of construction is as follows: 1. cleaning a foundation, and constructing a water inlet channel and a water collecting tank on one side of a river bank; building a fixed pier in a river bed; 2. prefabricating the following components according to design requirements in a factory: sand washing pipe, sand washing nozzle and water collecting tank top plate; 3. the factory prefabricated components are transported to the site for installation, wherein the components are threaded or flanged.

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