Chapter 1 Construction of the cofferdam lock status of development and research papers outlined the background and significance Research and abroad the domestic part of the foreign part of the The main work of this paper details are as follows PAH degradation genes Location of the research papers the purpose, significance and research contentChapter 2 Overview Xiangjiang River in Changsha lock Overview hydro-meteorological conditions, hydrological characteristics Temperature Precipitation Summary of engineering geological conditionsChapter 3 of the diversion and closure lock cofferdamDiversion of construction materials Special features of the cofferdam material shortages second-phase cofferdam construction period with a shortage of shipping materials for high diversion measures cofferdam closure design and construction. a closure means closure design calculation model diversion capacity calculation Longkou calculated discharge capacity design closure dike Longkou closure care at the end dumped material wrapped into account the pre-closure and closure head construction Longkou closure closure construction construction strength analysis key control SummaryChapter 4 cofferdam stability cofferdam rock slope stability checking the positive side the positive side concrete cofferdam longitudinal cofferdam slope stability checking back surface silty clay cofferdam downstream slope stability checking (vertical) dorsal surface of the water the sand cofferdam cofferdam slope material cofferdam stability checking the stability analysis of the top cover pre-filled diagonal panel outlet downstream longitudinal cofferdam stability analysis of calculated positive side slope cover the positive side of concrete longitudinal cofferdam sub-panel weir calculation of the positive side of silty clay slope stability checking checking seepage SummaryChapter 5, the main cofferdam construction Construction Construction of concrete film bag film bag ready to film bag laying of concrete panel construction of protective concrete filling concrete transportation construction program, warehousing concrete pouring protection of concrete products concrete curing construction Renault Renault pad pad pad assembly installed and filled Renault Summary