复杂地质大型承台深基坑钢板桩围堰施工技术

Construction Technology of Steel Sheet Pile Cofferdam for Deep Foundation Pit with Large Pile Cap Under Complex Geological Condition

大型承台深基坑支护结构形式与基坑的平面尺寸、基坑的深度以及承台所在的地质条件有较大的关系。论文主要研究钢板桩围堰在细卵石土与粉砂岩互层地质条件高速大河道中的应用。采用旋挖桩引孔的方式插打拉森钢板桩,承台混凝土分两次浇筑,分层拆除围堰内支撑,以避免钢板桩围堰内支撑与承台之间的干扰,以上方案确保了大型承台基坑围护结构的安全。

The choice for supporting structure of deep foundation pit has great relationship with its plane dimension,the depth as well as its geological condition.This paper mainly studies the application of steel sheet pile cofferdam in a large-high-velocity river which has the interbedded geological condition of fine cobbly soil and siltstone.In order to avoid the interference between internal support of the steel sheet pile cofferdam and the pile cap,the Larsen steel sheet pile is inserted by means of rotary digging,then pour concrete for pile cap in two times,the internal support of cofferdam is removed in layers.The scheme mentioned above ensures the safety of enclosure structure of deep foundation pit.