Regulation measures and effect analysis for the Shenbeizui shoal in the Yangtze River

Shenbeizui is of famous pebble shoals in Yinbin to Chongqing channel of the Yangtze River.Shenbeizui waterway is widened in flood periods,and branched into two channels during dry seasons.The left channel is curved and narrow,and the right channel is straight and broad-shallow.The regulation of the left channel was carried out in 1990,but the left channel was silted up immediately after regulation.Based on physical model and ship model tests,weakened navigability mechanism and regulation measures are studied.The results show that it is difficult to achieve permanent improvement of navigation conditions in the left branch,and it is feasible to implement regulation for the right channel so as to achieve better navigation conditions and a stable channel.Such regulation measures as dredging the right channel,converging flow and scouring sands,and adjusting diversion ratio of flow were adopted in the recommended right-channel alternative.The navigation condition of right channel is better after regulation.