福州世茂外滩花园深基坑支护及降水技术

Retaining and dewatering technology of deep excavation for Fuzhou Shimaowaitan Garden

福州世茂外滩花园#3楼深基坑位于闽江北岸深厚的砂性土层中,最大开挖深度达12.5 m,结合止水帷幕的设置,支护结构采用水泥搅拌桩与打入式土层锚杆组合支护结构。场地水位高且与闽江有直接水力联系,砂层渗透系数大,设计最大坑内水位降深为11 m,通过设置水泥搅拌桩悬挂止水帷幕,采用深井降水系统成功地降低了坑内水位。同时采用动态设计、信息化施工技术,成功地解决了较大范围厚乱块石岩土层的支护与止水等技术难点。本文详细介绍了设计思路和技术特点,以供类似工程借鉴。

The deep excavation of No. 3 building in Fuzhou Shimaowaitan Garden was located in the deep sand soil of north Minjiang River, with the maximum excavated depth being 12.5 m. The combined form of cement mixing pile wall and driven-into soil anchor was adopted as the retaining structures. Because of the high water level and large permeability in sand, the cement mixing pile was also used as the anti-seepage pensile curtain, and deep-well system was set up at the same time to depress the water line. To manage the complicated retaining and dewatering technology in unordered rock and soil layers, the dynamic design and informational construction was applied during the construction. The design ideas and technology management can be helpful to other similar projects.