向家坝二期截流设计及施工

向家坝水电站二期截流流量大、河床覆盖层深厚、龙口流速较大、抛投强度高,截流施工难度大。根据工程特点采取上游单戗双向进占的截流方式,以右岸进占为主,左岸为辅,龙口平抛护底。通过水力学计算成果,预留龙口宽80m,龙口分3个区进占,采取合理的堤头进占方式,保证抛投强度,确保了二期截流一举成功。

Closure Design and Construction of 2-stage of Xiangjiaba Project

There is considerable construction difficulty for the closure of 2-stage of Xiangjiaba Project due to high flow rate,thick sediment on river bed,high flow rate at closure gap and high dumping rate.After analyzing the the project characteristics,we suggest a single dike-bidirectional advancement strategy： advancing mainly from the right bank and supplementally from the left bank and horizontally dumping for bed protection.Through hydraulic computation,we suggest to reserve an 80 m closure gap,advance from three zones in a reasonable way to enhance dumping intensity.The presented methods has proven effective in the construction.