变位分配原理在地铁密贴穿越工程中的应用

Deformation distribution principle used in close-attached undercrossing engineering of subway station

北京新建地铁10号线车站密贴下穿既有1号线车站为北京市目前最大规模的密贴穿越工程,为保障既有线正常运行,要求下穿站施工引起的既有站满足沉降量小于3mm。结合平顶直墙CRD+多重预顶撑施工工艺,依据变位分配原理及数值计算结果,分析既有车站结构的变形特点及沉降规律,并以此制定了既有车站结构的分步变位控制标准;采用自动化与人工监测相结合的方式,将控制标准根据施工步序分解使用,分阶段控制工程自身及既有公主坟站的变形;对比分析计算值与实测值,实测值略大于计算值,但两者的沉降分布曲线大体一致,且各测点最终累计沉降值均满足3mm沉降控制指标。分析结果表明,变位分配控制原理在地铁密贴穿越工程,尤其是沉降控制标准严格的穿越工程中具有较高实用性,可为以后类似工程提供技术支持。

The Beijing 10 -line new Gongzhufen station passing beneath the existing subway line 1 station is cur rently the largest close - attached down tranversing project. In order to maintain normal operation of the existing line ,the settlement of existing station included showld be less than 3mm in the new station construction process. Combining the fiat top straight wall CRD with multiple pre back shore construction method, the structural deform- ation and the settlement regularity of the existing station were analyzed based on the deformation distribution principle and numerical results, and the distribution displacement control standards for each step were formulated. The control standards were decomposely utilized according to construction procedure on the basis of the combination of automated and artificial monitoring method so as to control this project step by step and the structural deformation of Gongzhufen station. With the comparison of the calculated and measured results, the measured result is a little greater than the calculated one, while both of the settlement distribution curves are almost unanimous, and the final settlement values of measuring points can meet settlement control index of 3 mm. The results show that deformation distribution principle has great availability on close -attached undercrossing engineering of subway station, especially in those with stringent settlement control standerds, and it can provide technicial assistance to similar project.