The secondstage foundation pit of the TGP will be bounded by the upstream and downstream transverse cofferdams and the longitudinal concrete cofferdam.
三峡工程二期上下游横向围堰与混凝土纵向围堰共同形成基坑，保证二期工程施工。
2
The research results show that the seepage stability can be guaranteed through the optimized design profile of the secondstagecofferdam.
研究成果表明，经过优化将要实施的二期围堰设计断面，渗透稳定是可以得到保证的。
3
The secondstage construction area on the main river bed is formed by the secondstage up & downstream transverse cofferdams and the longitudinal con crete cofferdam.