Development and Application of a New Auxiliary Diversion Structure for Mountain Ship Lock: A Case Study of Wuqiangxi Lock in China

Abstract

Ship locks on mountain rivers usually experience difficulties owing to harsh flow conditions such as strong oblique flow and backflow, which significantly affect navigation safety and efficiency. To improve navigation conditions, a structural measure involving pile-foundation permeable dislocation-type diversion vanes, a new type of diversion structure, is proposed by analyzing the features and working mechanisms of the existing diversion structures. Based on a typical mountain ship lock—the Wuqiangxi Lock—model tests including various schemes were conducted to investigate the effects of the new diversion structure. The new diversion structure obtained better results than other existing diversion structures, particularly in terms of reducing the transverse flow velocity extremums. By controlling the diversion volume, stabilizing the deflection angle, and dissipating the flow energy, the new diversion structure could effectively weaken the oblique flow intensity at the entrance area. In addition, comparisons of its cost efficiency with that of a hybrid measure combining riverbed dredging and diversion piers was carried out. Moreover, its performance of practical application in the reconstruction project of the Wuqiangxi Lock was demonstrated. Based on the investigation presented herein, the new diversion structure is a promising approach for improving flow conditions at the entrance area of the lock approach.