Dredging method for reservoir area beach land

Abstract

The invention discloses a reservoir area beach land desilting method which comprises the steps that (1) a buoyancy tank dam body is arranged at the narrow position of the upstream of an artificial channel; (2) a plurality of artificial channels are dug in the reservoir area beach land on one side or two sides of a riverway main channel in sequence; (3) the draft depth and the water retaining angle of the buoyancy tank dam body are adjusted; water flow in the main channel of the river channel is guided into the artificial channel closest to the main channel of the river channel, and under the combined action of base flow scouring and transverse scouring of the water flow, deposits between the artificial channel and the main channel of the river channel are flushed to the front dam sand discharging funnel of the reservoir area dam and are discharged to the downstream of the dam through the flood and sand discharging bottom hole. And (4) repeating the step (3) until the desilting work of the reservoir area beach land is completely completed. Compared with other mudflat siltation treatment measures, the method has the advantages that investment is saved, equipment can be sustainably utilized, and the mudflat desilting effect is obvious, the reservoir area beach storage capacity and the main groove storage capacity can be increased, the beach storage capacity can be kept for a long time, and therefore the purpose of increasing the effective storage capacity of the reservoir is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of reservoir dredging in water conservancy projects, and in particular to a reservoir beach dredging method. Background Art

[0002] At present, my country has built nearly 100,000 reservoirs, which have made great contributions to the balanced allocation of water resources, flood control in river basins, and agricultural irrigation in my country. However, after the reservoir is filled with water, the water flow velocity decreases, resulting in a decrease in its sediment carrying capacity, which causes a large amount of sediment to accumulate in the reservoir section in front of the dam. Most of my country's reservoirs were built from the 1950s to the 1980s. At that time, there was little consideration of the sediment accumulation problem in the reservoirs. Coupled with the extension of the operation time of the reservoirs, most reservoirs, especially those built on sandy rivers, have experienced serious sedimentation. Some reservoirs have changed their original operation mode due to siltation and completely lost the functions of the reservoir design. The commonly used sediment removal measures currently include hydraulic dredging and mechanical dredging. Among them, hydraulic dredging mainly includes flood retention and sediment discharge, emptying and sand flushing, base flow scouring and other measures; mechanical dredging measures mainly use mechanical equipment, such as dredgers, suction dredgers, suction dredgers, mud pumps and other mechanical equipment to clean up the sediment in the reservoir area under manual operation. The above two dredging methods both have the disadvantages of low dredging efficiency, large amount of discarded water, high cost, limited dredging range, and inability to deal with beach siltation. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a method for dredging beach in a reservoir area, which can specifically adopt the following technical solutions: The reservoir beach dredging method of the present invention comprises the following steps: The first step is to set up a pontoon dam at a narrow place upstream of the main channel of the river, wherein a filling and drainage mechanism is arranged in the pontoon dam; The second step is to sequentially excavate a number of artificial channels on the reservoir beach on one side or both sides of the main channel of the river. The artificial channels are arranged in the same direction as the main channel of the river and extend from the pontoon dam body to the reservoir dam; The third step is to adjust the draft depth and water retaining angle of the pontoon dam body to divert the water flow in the main channel of the river to an artificial channel closest to the main channel of the river. Under the combined effects of base flow scouring and lateral erosion, the silt in the artificial channel and between it and the main channel of the river are washed to the sand discharge funnel in front of the reservoir dam, discharged to the downstream of the dam through the flood discharge and sand discharge bottom holes, and discharged downstream with the water flow of the main channel behind the dam; Step 4: Repeat step 3 until the dredging of the reservoir beach is completed.

[0004] Preferably, the artificial trenches are excavated by an excavator, and each artificial trench has a width of 2.5-3.0 m and a depth of 1.0-1.5 m.

[0005] Preferably, the pontoon dam body is assembled from one or more pontoon units.

[0006] Preferably, the pontoon unit comprises a shell, and ear plates for passing connecting bolts are arranged at both ends of the top of the shell, and the filling and drainage mechanism comprises a water tank arranged in the shell, and the water tank is provided with a filling pipe and a drainage pipe extending to the outside of the shell.

[0007] Aiming at the existing problems in the desilting of beach land in the reservoir area, the present invention proposes a method for comprehensively treating beach land siltation, especially treating high beach siltation, based on the basic principles of water-binding and sand-attacking, base flow scouring and water flow lateral erosion. By setting a light and easy-to-assemble floating box dam body at the narrow upstream of the main channel of the river channel, the water flow is sequentially introduced into the nearest artificial channel, thereby increasing the water flow velocity carrying the silt, and utilizing the combined effects of water flow base flow scouring and lateral erosion to discharge the silt through the flood discharge and sand discharge bottom holes of the original dam body to the downstream of the dam, thereby achieving the purpose of continuous silt discharge. Compared with other beach land siltation treatment measures, the present invention has the advantages of saving investment, sustainable use of equipment, and obvious beach land desilting effect. It can not only increase the beach storage capacity and main channel storage capacity of the reservoir area, but also maintain the beach storage capacity for a long time, thereby achieving the purpose of increasing the effective storage capacity of the reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram of the arrangement of the dredging mechanism in the present invention.

[0009] Figure 2 It is a schematic diagram of diverting water to an artificial channel in the present invention.

[0010] Figure 3 It is a schematic diagram of the dredging effect after water is diverted to the artificial channel in the present invention.

[0011] Figure 4 It is a structural schematic diagram of the buoyancy unit described in the present invention.

[0012] Figure 5 It is a schematic diagram of the natural cross-section of the river.

[0013] Figure 6 This is a schematic diagram of the river siltation section after the construction of the reservoir.

[0014] Figure 7 It is a schematic diagram of the construction position of the dredging works described in the present invention.

[0015] Figure 8 It is a schematic diagram of the cross section of the river after the desilting works described in the present invention are operated. DETAILED DESCRIPTION

[0016] The following is a detailed description of an embodiment of the present invention in conjunction with the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiment.

[0017] exist Figure 5 After a reservoir is built on the sandy river shown in the figure, it will form the following after a long period of operation. Figure 6 The siltation phenomenon shown in the figure affects the reservoir water storage and flood control. Therefore, considering dredging, the following Figure 7 The desilting works shown in the figure were continuously carried out to remove silt, and finally the following Figure 8 The dredging effect is shown.

[0018] The reservoir beach dredging method of the present invention comprises the following steps: The first step, such as Figure 1 As shown, a pontoon dam body 2 is arranged at a narrow upstream portion of the main channel 1 of the river channel, and the pontoon dam body 2 is assembled from one or more pontoon units.

[0019] like Figure 4 As shown, each pontoon unit includes a shell 21, and ear plates 22 for inserting connecting bolts are provided at both ends of the top of the shell 21, which can be easily assembled and improve the assembly speed. The pontoon unit also includes a filling and drainage mechanism, which includes a water tank arranged in the shell 21, and a water filling pipe and a drainage pipe extending to the outside of the shell 21 are provided on the water tank, and the draft of the pontoon dam body 2 can be adjusted by filling and discharging water.

[0020] The second step is, Figure 1 As shown, several artificial channels are excavated in sequence on the reservoir beach on one side or both sides of the main channel 1 of the river. In this embodiment, two artificial channels are included, namely a first artificial channel 31 closer to the main channel 1 of the river and a second artificial channel 32 farther from the main channel 1 of the river.

[0021] The first artificial channel 31 and the second artificial channel 32 are arranged on the same side of the main channel 1 of the river channel. Both are arranged in the same direction as the main channel 1 of the river channel and extend from the pontoon dam body 2 to the reservoir dam 4.

[0022] When excavating the artificial channel, the principle of simple construction and economic rationality is followed. The single scouring and silting capacity of the main river channel water flow is also considered. A mature excavator is selected for excavation. The width of the above-mentioned bucket is generally 2.98m. Therefore, in this embodiment, the width of the first artificial channel 31 and the second artificial channel 32 are both about 2.98m, and the depth is 1.0m to 1.5m, so as to facilitate the lateral erosion of the water flow.

[0023] The third step is to adjust the draft depth and water retaining angle of the pontoon dam body 2 to divert the water flow in the main channel 1 to the first artificial channel 31 closest to the main channel 1. Under the combined effects of base flow scouring and lateral erosion, the first artificial channel 31 and the sediment between it and the main channel 1 are washed to the sand discharge funnel in front of the reservoir dam 4, and discharged to the downstream of the dam through the flood discharge and sand discharge bottom hole 5, and discharged downstream with the water flow of the main channel behind the dam. At this time, the first artificial channel 31 is merged into the main channel 1.

[0024] The fourth step is to repeat step three, that is, by adjusting the draft depth and water retaining angle of the pontoon dam body 2, the water flow in the main channel 1 of the river channel is directed to the second artificial channel 32 closest to the main channel 1 of the river channel. Under the combined action of the base flow scouring and lateral erosion of the water flow, the silt in the second artificial channel 32 and between it and the main channel 1 of the river channel is washed to the sand discharge funnel in front of the reservoir dam 4, and discharged to the downstream of the dam through the flood discharge sand discharge bottom hole 5, and discharged to the downstream with the water flow of the main river channel behind the dam. At this point, all the dredging work of the reservoir beach is completed.

[0025] It should be pointed out that no matter how many artificial channels there are, the water flow in the main channel 1 of the river channel is only directed to one artificial channel in the same period of time, so as to ensure the scouring and silt removal ability of the water flow. When the artificial channel washes the silt into the main channel 1 of the river channel due to lateral erosion and hydraulic scouring, the position of the pontoon dam body is adjusted to guide the water flow to another artificial channel.

[0026] It should be noted that, in the description of the present invention, terms indicating orientation or positional relationships, such as "front", "rear", "left", "right", "vertical", "horizontal", "inside", "outside", etc., are based on the orientation or positional relationships shown in the drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

Claims

1. A method for dredging beach in a reservoir area, characterized in that: The steps include: The first step is to set up a pontoon dam at a narrow place upstream of the main channel of the river, wherein a filling and drainage mechanism is arranged in the pontoon dam; The second step is to sequentially excavate a number of artificial channels on the reservoir beach on one side or both sides of the main channel of the river. The artificial channels are arranged in the same direction as the main channel of the river and extend from the pontoon dam body to the reservoir dam; The third step is to adjust the draft depth and water retaining angle of the pontoon dam body to divert the water flow in the main channel of the river to an artificial channel closest to the main channel of the river. Under the combined effects of base flow scouring and lateral erosion, the silt in the artificial channel and between it and the main channel of the river are washed to the sand discharge funnel in front of the reservoir dam, discharged to the downstream of the dam through the flood discharge and sand discharge bottom holes, and discharged downstream with the water flow of the main channel behind the dam; Step 4: Repeat step 3 until the dredging of the reservoir beach is completed.

2. The reservoir beach dredging method according to claim 1, characterized in that: The artificial trenches are excavated by an excavator, and each artificial trench has a width of 2.5-3.0 m and a depth of 1.0-1.5 m.

3. The reservoir beach dredging method according to claim 1, characterized in that: The pontoon dam body is assembled from one or more pontoon units.

4. The reservoir beach dredging method according to claim 3 is characterized by: The pontoon unit comprises a shell, and ear plates for passing connecting bolts are arranged at both ends of the top of the shell. The filling and drainage mechanism comprises a water tank arranged in the shell, and a filling pipe and a drainage pipe extending to the outside of the shell are arranged on the water tank.

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