临涣船闸下游引航道优化设计

Optimal design of downstream approach channel of Linhuan ship lock

临涣船闸位于临涣节制闸南侧,上距省界李口集约30.0 km,下距南坪闸31.5 km,下游引航道连接段位于转弯河段,弯道转角约75°。受此地形影响,河道主流贴右岸凸嘴进入下游主河槽,使引航道连接段与凹岸之间形成逆时针回流,对引航道水流有压迫作用,局部主流宽度显著束窄。通过物模试验可知,河道主流对引航道口门区内水流形成较为明显的剪切,导致口门区内形成较大范围的回流,长度近350 m。由于回流区较长,形成多个复杂的异向回流组合流态,水流条件十分复杂,因此需提出相应的工程措施加以改善。通过河槽疏浚、增加隔流潜堤,有效地解决了下游引航道水流流态不佳、横向流速超标较大、口门区回流强度较大、回流流速无法满足规范要求的问题。

Linhuan ship lock is located in the south of Linhuan control lock,about 30.0 km away from Likouji,the provincial boundary,and 31.5 km away from Nanping lock.The connecting section of the downstream approach channel is located in the turning river section,with a turning angle of about 75°.Affected by the terrain,the main stream of the river flows into the downstream main channel close to the convex nozzle on the right bank,resulting in counterclockwise reflux between the connecting section of the approach channel and the concave bank.This exerts a compressive effect on the approach channel flow,with significantly narrowed width of the local mainstream.The physical model test shows that the mainstream of the river forms an obvious shear to the flow in the entrance area of the approach channel,resulting in a large reflux range in the entrance area with a length of nearly 350 m.As a result,multiple complex reverse reflux combined flow patterns are formed,and the flow conditions are very complex.Therefore,corresponding engineering measures should be put forward for improvement.By dredging the channel and increasing the separation submerged dike,we solve the poor flow pattern in the downstream approach channel,large cross-flow velocity exceeding the standard,large reflux intensity in the entrance area,and inability to meet the specification requirements.