河漫滩地区地铁车站深基坑变形规律

Deformation Law of Deep Foundation Pit for Metro Station in Flood Plain Area

针对太原市汾河地区河漫滩地层,以双塔西街站深基坑为研究对象,利用有限差分软件FLAC 3D对开挖过程中基坑的变形规律进行了研究。结果表明:地表沉降整体呈凹槽型,最大沉降发生在距离基坑边缘0.5~0.6倍基坑深度处,影响范围为3倍基坑深度;河漫滩地区适于将插入比控制在0.9左右。根据正交试验,双塔西街站施工时支护参数宜采用插入比1.0,地下连续墙厚度1 000 mm,内支撑纵向间距6 m。

Based on the flood plain stratum in Fenhe area of Taiyuan,the deformation lawof foundation pit during excavation was studied by using the finite difference software FLAC 3D and taking the deep foundation pit of the Shuangta Xijie station as the research object. The results showthat the overall surface subsidence shows a groove shape,the maximum subsidence occurs at the position which is 0. 5 to 0. 6 times the depth of the foundation pit from the foundation pit edge,the influence area is 3 times the depth of foundation pit,and the insertion ratio should be about0. 9 in flood plain area. As the support parameters,the insertion ratio should be 1. 0,the thickness of diaphragm wall should be 1 000 mm and the longitudinal spacing ofinner support should be 6 m according to orthogonal test during the Shuangta Xijie station construction.