高低异形刃脚钢围堰在望东长江公路大桥主墩施工中的应用

望东长江公路大桥是主跨为638m的双塔组合梁斜拉桥，南塔主墩处河床为裸露大倾斜中风化灰岩，若按常规方法施工，则无覆盖层条件下钻孔平台搭设困难，故基础采用高低异形刃脚钢围堰施工。该围堰四周韧角可以依据河床岩面形状进行调整，适用于不同地质条件下无覆盖层的河床岩面。钢围堰施工所采用的整体翻转施工工艺，不仅可以满足渡洪要求，而且还可有效缩短工期，可供类似环境条件下钢围堰的设计、施工借鉴。

Application of High-low Special-shaped Blade Angle Steel Cofferdam in Construction of Main Piers of Wangdong Yangtze River Highway Bridge

Wangdong Yangtze River Highway Bridge is a twin-tower composite beam cable-stayed bridge with 638m main span, its main tower adopts diamond bridge tower structure and the river bed at main pier of south tower is covered by naked large tilt intermediary weathering limestone. If conventional methods are adopted in construction, erection of drilling platform under the condition of no covering layer is difficult, therefore, the foundation is constructed by means of high-low special-shaped blade angle steel cofferdam. The surrounding toughening angles of the cofferdam can be adjusted in accordance with the shapes of rockface and are applicable to rockfaces of river bed without covering layer under different geological conditions. The overall overturn technology is adopted in construction of steel cofferdam, not only satisfying the requirement of flood crossing, but can shorten period of construction effectively, and providing a reference for design and construction of steel cofferdams under similar environmental conditions.