逆作土方通道式施工工艺对基坑变形的影响

采用软土蠕变（SSC）模型模拟不同工况下基坑开挖的全过程，对比分析了不同施工工艺对基坑围护变形以及其周边环境的影响.结果表明：逆作土方通道式施工工艺与传统施工工艺的基坑围护变形特征相似，且通道式施工工艺可有效控制围护结构的变形，减小坑外土体的最大沉降量、坑底隆起量和坑外土体侧向变形，对周边环境起到了较好的保护作用；当考虑上覆列车荷载时，逆作土方通道式施工工艺所产生的铁路路基变形在铁路正常运营范围以内.

Effect of Channel-Type Transport Technology of Earthwork on the Deformation of Top-Down Deep Foundation Pit

The soft soil creep(SSC) model was adopted to simulate the whole process of a deep foundation pit with different construction conditions.Comparisons of the effect of different construction technologies on the deformation of foundation pit and the surroundings were made.The results show that the deformation features of the foundation pit under both construction technologies are similar.The top-down channel-type construction technology is more effective on controlling the deformation of the enclosure structures,and has less impact on the surrounding by decreasing the ground settlement,the lateral displacement of soil outside the pit and the upheaval mount of soil at the pit bottom.While considering the train load,with top-down channel-type construction technology,the deformation of the railway subgrade is safe.