富水细砂地层盾构斜向超近距下穿双洞双线暗挖站施工技术

为研究富水细砂地层某盾构区间斜向超近距下穿施工对既有地铁站变形的影响,文章以临近既有地铁站暗挖段的新建地铁盾构区间工程为背景,对地铁盾构区间工程施工进行设计,并用MIDAS计算分析程序对富水细砂地层盾构斜向超近距下穿既有地铁站施工过程进行数值计算分析。总结了盾构斜向超近距下穿施工过程中既有地铁站位移变化特征;研究了既有地铁站明暗挖交界处变形缝差异沉降规律;分析了既有地铁站轨道沉降变化趋势;整理施工监测数据结果并与模拟计算趋势比对,变化规律基本一致,侧面印证了仿真计算的准确性。

In order to study the influence of inclined ultra-close shield underpass construction on the deformation of existing metro station in water-rich fine sand stratum, the newly-built metro shield section near the underground excavation section of an existing metro station is taken as an example, and MIDAS program is used to calculate and analyze the shield construction process underpassing the existing metro station in inclined ultra-close distance in water-rich fine sand stratum. The characteristics of the displacement variation of the existing metro station in the process of the shield construction are summarized, the differential settlement law of the deformation joint at the junction of the open and underground excavation of the existing metro station is studied, and the variation trend of the track settlement of the existing metro station is analyzed. The variation rules obtained from the monitoring data of the construction are basically consistent with those of simulation calculation, which proves the accuracy of simulation calculation.