River dredging is a basic and key river management work, but for rural areas, due to lack of construction funds and proper management, the river is often silted up, affecting the smoothness of the river, which reduces the ability to fight flood. Therefore, how to effectively clean up the silt in the rural river is worthy of in-depth discussion.
Commonly Used River Dredging Technology:
1. Drainage Dredging Technology
Drainage dredging technology mainly includes two types: direct excavation and water flushing. Among them, direct excavation technology is also known as dry excavation construction technology, that is, first drain the water in the river, and remove the silt accumulated in the river with the help of digging equipment, and then transport it out with the help of muck truck or temporarily accumulate it at the site. This kind of dredging technology has low requirements for construction technology and equipment, but dredging is not thorough enough, easy to harm the buildings on both sides of the river. The water flushing technology is to wash the silt accumulated at the bottom of the river with the help of water conservancy flushing machinery and equipment, stir it into mud, and then guide it into preset low-lying areas by mud pumps and pipelines for piling. This type of silting equipment is simple and easy to transport mud, thus enjoys low cost. However, it can only be applied to non-flood season and will be affected by weather factors.
According to the different dredging equipment, the underwater dredging technology can be divided into grab type, pump suction type and suction type. Among them, the grab type dredging technology mainly uses the grab dredger to dig out the bottom of the river silt, which enjoys very strong maneuverability and flexibility, and is simple with low cast at the same time. It will neither affect the buildings on both sides of the river, so is mainly suitable for thick mud with more obstacles. But its desilting efficiency is relatively low. The pump suction underwater dredging technology is to use the mud pump and flushing gun to stir the silt into slurry before discharging it. Equipment required for this type of dredging technology is comparatively simple, and feasible to be carried out in any section of the channel, but it will pump out the slurry of the river at the same time which increases the difficulty of subsequent slurry treatment. The cutter-suction type dredging technology is to use the suction dredger for river dredging construction. It is mainly suitable for the places with thick mud, and it covers the work of silt excavation and transportation, and won’t have mud leakage problems in the process. Especially with the help of the echo detector and GPS application it improves the dredging efficiency. However, the cost is high, flexibility is insufficient, Therefore, it is not suitable for river dredging in rural areas.
3. Environmental Protection Dredging Technology
The environmental protection dredging technology will not lead to problem of the original soil, at the same time will not disturb the river or pollute the water, nor will it affect the life of surrounding residents. This technology is able to improve the water quality of the river after dredging construction-specifically it applies special spiral dredging device or closed rotary bucket wheel dredging equipment to dredge the river silt, and makes the use of compressed air and hydrostatic pressure to remove the silt of the river bottom. The equipment does not disturb the bottom of the river and will not pollute the surrounding waters. Environmental protection dredging technology can avoid missing excavation, over-excavation or damage to the river.