Relatively Large Number of Piers Designed for Shenyang Air-Cushioned Shield Sluices

Comparison of sluice (dam) types For mountainous rivers, the flood discharge is large and the flood control water level line is high. In order to avoid the elevation of water level line caused by backwater in the upstream of sluice (dam), the traditional fixed overflow dams such as masonry and concrete are obviously not suitable for construction in urban scenic rivers. For the traditional sluice. Because of the large flow and wide river channel, it is necessary to set a very large span of the gate, and it is difficult for the basic gate to meet such conditions. No matter whether it is a vertical, horizontal, flat or arc gate, the width of the single hole of most gate types is limited. There are a large number of piers of Shenyang Air Shield, and the water blocking effect of the piers will immediately cause backwater on the dam and push up the water surface line, which will cause greater pressure on flood control on both sides and meet the high position. At the same time, auxiliary equipment such as working bridge, maintenance corridor and hoist need to be set, which increases the investment of the project. Therefore, this kind of movable dam type should adopt open long-span gate or movable dam type that can be opened flexibly. According to the hydrological and sediment characteristics of rivers in hilly areas, the pneumatic shield gate system is compared with five dam types: hydraulic automatic flap gate, hydraulic flap gate, hydraulic steel dam (bottom shaft driven flip gate), rubber dam and hydraulic lifting dam.

 

 Comparison between Shenyang air shield gate and hydraulic automatic flap gate (1) The air shield gate is not connected with the middle pier, and the water flow pattern is good. There is a supporting pier behind the hydraulic automatic flap gate, and sometimes there is a protective pier in front of the flap gate for protecting the supporting parts, which is easy to jam and block water, and the water flow pattern is poor. (2) The air shield gate does not need river regulation, which will not cause river siltation and will not be blocked by floating objects and silt. The hydraulic automatic flap gate is easily affected by silt or floating objects, so it can't be opened and closed normally: (3) The pneumatic shield gate has good sealing performance and is not easy to leak; (4) The pneumatic shield gate itself does not block water, but completely falls and discharges water, and a thick water blocking surface is formed in the middle of the hydraulic automatic flap gate, which affects the flood discharge section and is impacted by the flood; (5) The ups and downs of Shenyang Air Shield Gate can be controlled, and the downstream danger will not be caused by unpredictable lodging. The working principle of hydraulic automatic flap gate is to use the balance between water pressure and self-weight, so that the gate body can be opened automatically, which is not controlled by people. In addition, it is difficult to control the appropriate opening time. When the gate is opened for flood discharge, it will often cause sudden flood peak to the downstream, causing some damage.