CN107460846A - A kind of soft dam system of becoming silted up certainly for being used to prevent and treat Canal in Loess Area groove channel erosion - Google Patents

Abstract

Aiming at the problem of loess slope channel erosion, the present invention proposes a self-silting soft dam system for preventing and controlling channel erosion in loess areas, which is different from the traditional design concept. The self-silting soft dam system is composed of a permeable sedimentation system and a siphon drainage system. The channel permeable sedimentation system realizes the separation of water and sand, and discharges the separated water flow to the downstream safe area through siphon action, and the sediment will form a wide and gentle self-silting soft dam under the action of repeated sedimentation in the channel of the water-sand diversion section. The invention realizes the separation of water and sand by combining the permeable sedimentation system and the siphon drainage technology, and the sediment is not only kept but also fully utilized. The cascaded self-silting soft dam changes the terrain conditions of the channel, reduces the erosion and scour of the channel, and at the same time avoids water and soil loss. The self-silting process is free of power generation, saving a lot of manpower and material resources.

Description

A self-silting soft dam system for preventing channel erosion in loess areas

technical field

The invention belongs to the field of water conservancy engineering, in particular to a structure or system for preventing and controlling channel erosion in loess areas.

Background technique

In my country's Shanxi, Shaanxi, Gansu, Ningxia, Qinghai, Inner Mongolia, Henan and other provinces, loess is widely distributed, with low vegetation coverage, loose soil and strong water sensitivity. Affected by the monsoon climate, the precipitation in the loess area is concentrated, and most of them are torrential rains. Under the action of runoff, gully erosion is prone to occur, water and soil loss occurs, resulting in fragmented terrain and ravines in the region, deterioration of production conditions and ecological environment, and severe ecological security situation, which has become a constraint Major strategic issues of social and economic sustainable development in the loess area. Gully erosion is formed under the combined action of water flow and its own gravity. Gully erosion can be divided into different stages such as rill erosion, shallow trench erosion, and channel erosion according to the shape and evolution process. Loess ditches and tributary ditches often have the characteristics of large terrain slope, narrow ditch width direction, and limited water catchment area. Traditional check dams have low efficiency in retaining sand and silting soil in middle and upper ditches and tributary ditches, and poor economic benefits. It is of great practical significance to study light-weight dispersed silt retention technology, change the concentrated accumulation of intercepted sediment in front of the dam to distributed accumulation in ditches, and realize the economic interception of sediment in the watershed and the efficient utilization of water resources.

Contents of the invention

Aiming at the problem of channel erosion in the loess area, the present invention proposes a self-silting soft dam system different from the traditional design concept, which uses the channel permeable sedimentation system to realize the separation of water and sand, and discharges the separated water flow to the downstream safe area through siphon action, and the sediment Then, the self-silting dam will be formed under the action of repeated erosion and deposition in the channel in the water-sand diversion section, so as to change the slope rate of the channel and slow down channel erosion and soil loss.

The technical solution of the invention is: a self-silting soft dam system for preventing and controlling channel erosion in loess areas, including a permeable sedimentation system and a siphon drainage system. The permeable sedimentation system includes plastic blind ditch and geotextile. The trench is excavated at the bottom of the ditch, and multiple plastic blind ditch are placed in the trench. The cross section of the plastic blind ditch is rectangular, and the plastic blind ditch is wrapped with geotextile. The sandy water in the channel flows through the permeable sedimentation system, and the water and sand are separated, and the sediment is repeatedly washed and silted on the bottom slope of the channel to form a self-silting soft dam; the siphon drainage system includes a diversion tank, a cover plate, a drainage siphon, and a plastic blind ditch. The water outlet is connected to the diversion tank, the top of the diversion tank is provided with a cover plate, and the side wall of the diversion tank is provided with an opening, the height of the opening is more than 30cm lower than the top of the diversion tank, and the diameter of the opening is the same as that of the drainage siphon , the water inlet of the drainage siphon extends into the diversion tank, and the outlet of the drainage siphon passes through the opening on the side wall of the diversion tank and is placed in a downstream safe area.

Further, the depth of the diversion pool is 2m-4m, and the length and width of the diversion pool are 0.8m-1m.

Further, there are one or more drainage siphons in the siphon drainage system, with a diameter of 200-500 mm.

When heavy rainfall occurs, the runoff scours the slope and enters the ditch, where it gathers into a sandy water flow. When the sandy water flows through the permeable sedimentation system of the self-silting soft dam system, the water flows into the plastic blind ditch through the geotextile. The water flows through the plastic blind ditch and enters the diversion tank. When the water level in the diversion tank is higher than the opening on the side wall of the diversion tank, the drainage process occurs, and the siphon effect starts. The drainage siphon drains the water in the diversion tank to the downstream safe area. As a result, the sediment in the diversion tank will be sucked out by the drainage siphon, and the sediment in the diversion tank will not be deposited. After the water and sand in the ditch are separated, the sediment deposits on the bottom slope of the ditch. Rainfall and runoff occur repeatedly, and the sediment is repeatedly eroded and deposited in the ditch in the water-sediment diversion section to form a wide and gentle self-silting dam. As the height of the self-silting dam increases, the permeability of the permeable sedimentation system gradually decreases, and the sediment-laden water flow will pass through the previously formed self-silting dam more, making the width of the self-silting dam gradually increase. Since the formation of the silting dam, the terrain conditions of the channel have been changed, the slope rate of the channel has been slowed down, the velocity of water flow has been reduced, the erosion and erosion of the channel have been reduced, and soil erosion has been avoided.

The advantages of the present invention are explained in conjunction with the contents of the present invention as follows:

1. The combination of permeable sedimentation system and siphon drainage technology is used to realize the separation of water and sand. The water is transported to the downstream safe area, and the sediment is deposited on the bottom slope of the channel to form a self-silting soft dam. The sediment is not only maintained but also fully absorbed. use.

2. Use cascaded self-silting dams to change the terrain conditions of the channel, slow down the slope rate of the channel, reduce the flow rate of the water, reduce the erosion and erosion of the channel, and avoid soil erosion at the same time. The self-silting process occurs without power, saving a lot of manpower and material resources.

3. Siphon drainage has the function of dredging, which can remove the sediment entering the diversion tank, so as to avoid silting and cause the diversion tank to lose the water collection effect, which can ensure the effective work of the system.

Description of drawings

Fig. 1 is the overall structural representation of the present invention;

Fig. 2 is the sectional view of A-A section among Fig. 1 of the present invention;

In the figure: sandy water flow 1, channel 2, plastic blind ditch 31, geotextile 32, trench 33, self-silting soft dam 4, diversion pool 51, cover plate 52, drainage siphon 53.

detailed description

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

As shown in FIG. 1 , a self-silting soft dam system for preventing channel erosion in loess areas includes a permeable sedimentation system and a siphon drainage system. The permeable sedimentation system includes a plastic blind ditch 31 and a geotextile 32 . As shown in Figure 2, a trench 33 is excavated at the bottom of the trench 2, a plastic blind ditch 31 is placed in the trench 33, the plastic blind trench 31 is wrapped with a geotextile 32, and the sandy water flow in the trench 2 After passing through the permeable sedimentation system, the water and sand are separated, and the sediment is repeatedly washed and silted on the bottom slope of the channel 2 to form a self-silting dam 4; The water outlet is communicated with the diversion tank 51, and the four walls and the bottom surface of the diversion tank 51 are lined with concrete, and the thickness is 30cm. The depth of the diversion tank 51 is 3m, and the length and width of the diversion tank 51 are 1m. Plate 52, the side wall of diversion pool 51 is provided with perforation, and the height of perforation is lower than the top 30cm of diversion tank 51, and the diameter of perforation is identical with the pipe diameter of drainage siphon 53, and the pipe of drainage siphon 53 in siphon drainage system The diameter is 300mm, and the water inlet of the drainage siphon 53 extends into the diversion tank 51, and the water outlet of the drainage siphon 53 passes through the opening of the side wall of the diversion tank 51 and is placed in a downstream safe area. The self-silting soft dam system used to prevent channel erosion in the loess area of the present invention can be installed in multiple sections of the channel at different elevations, and is distributed in a cascading manner. The number of steps depends on the length of the channel, slope rate, rainfall, etc. factor is determined.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, etc. within the scope of the present invention shall be included in the protection scope of the present invention within.

Claims (3)

1. A self-silting soft dam system for preventing and controlling ditch erosion in loess areas, comprising a permeable deposition system and a siphon drainage system; the permeable deposition system includes plastic blind ditch and geotextile, and excavates trenches at the bottom of the ditch, Place multiple plastic blind ditches in the trench. The cross-section of the plastic blind ditches is rectangular. The plastic blind ditches are wrapped with geotextiles. The sandy water in the ditches flows through the permeable sedimentation system and the water and sand are separated. The bottom slope is repeatedly eroded and silted to form a self-silting dam; the siphon drainage system includes a diversion tank, a cover plate, and a drainage siphon. The outlet of the plastic blind ditch is connected to the diversion tank. There are holes, the height of the holes is 30cm lower than the top of the diversion tank, the diameter of the holes is the same as the diameter of the drainage siphon, the water inlet of the drainage siphon extends into the diversion tank, and the outlet of the drainage siphon passes through the diversion tank The opening of the side wall is placed in the downstream safe area. 2. A kind of self-silting soft dam system for preventing and controlling channel erosion in loess area according to claim 1, characterized in that, the depth of the diversion pool is 2m～4m, and the length and width of the diversion pool are 0.8 m ~ 1m. 3. A kind of self-silting soft dam system for preventing and controlling channel erosion in loess area according to claim 1, characterized in that, the drainage siphon in the described siphon drainage system is one or more, and the pipe diameter is 200～500mm.