Based on the engineering analogy, theoretical analysis,economic and technological comparison,the optimization and adjustment of the cofferdam of JinpingⅠHydropower Station was carried out.Through the study, the axis of the upstream cofferdam moved up;the structures of upstream and downstream cofferdam were optimized and adjusted ;the scheme of abutment excavation was optimized;the working duration of high slope excavation on abutment was shorten;the security risk and soil erosion during the construction were reduced,and the cofferdam and foundation pit safety was ensured during the water holding period since 2007.After the optimization and adjustment of cofferdam,10% of the investment is saved, 15% of the construction period is limited.
