Planning and design of construction diversion for Xiangjiaba Hydropower Station

In light of the special natural conditions and project layout characteristics of Xiangjiaba Hydropower Station,a stage diversion scheme with the left bank being closed at the first stage and the right bank closed at the second stage has been selected through comparison of several schemes under the consideration of the aspects such as construction layout,late-stage flood control,navigation during the construction,and the construction period before the commissioning of the first hydropower generating unit.The construction scheme is briefly introduced herein,and furthermore,the diversion structures,the composite scheme consisting of open caisson group adopted to treat the overburden of the foundation for the Stage 2 longitudinal concrete cofferdam and the diversion method of bottom outlet combined with the dam gap used for the Stage 2 diversion are described as well.