单支点排桩结合双排桩在基坑支护中的应用

Application of Single Fulcrum Row Pile Combined Double-row Piles in Pit

单支点排桩支护在江苏苏州地区地下2层的基坑中已广泛应用,但其尚有一定的局限性,如需设置立柱、制作及养护耗工期、影响土方开挖等。在设置二层地下室形状近似正方形的基坑中,单支点排桩结合双排桩支护结构可在主楼不靠坑边的基坑中应用。该支护形式可实现主楼以最快速度先出地面的特殊目标,此外,其不仅工程造价节省且工期优势明显。对实测深层水平位移与理论计算比较的研究表明,对基坑边长较大的基坑,支护结构位移理论计算较实测结果偏小,需考虑基坑空间效应对支护结构变形的影响。

Single fulcrum row rile supporting system is widely used in underground two-story excavation at Suzhou area. However,there are certain limitations,such as needing upright column; time-consuming in production and conservation period,affecting earth excavation etc. In underground two-story excavation which approximate square shape,the supporting structure what combined double-row piles portal frame structure with single fulcrum row pile can be applied to that the main building does not does not step aside in excavation. The retaining form can achieve specific goal that the main building at the fastest velocity first-out ground,furthermore,the advantages of shorter construction duration and lower cost are obvious. By comparing the measured horizontal displacement with the theoretical calculations,the study shows that for the larger side of excavation,theoretical displacement is smaller than the experimental results,it is necesarry to consider the spatial effect of excavation impacting on supporting structure deformation.