明挖车站盾构井环框梁的受力分析及优化设计

摘要

Based on the study of an open-cut station on Changsha Metro Line 3 , this paper addresses the stress status and optimal design of the ring-beam in shield shaft. Load combinations are calculated on the bases of the limit of load bearing, and the internal structure stress of the ring-beam is analyzed with 3D model and plan model respectively. The comparison of the results from 3D and 2D model and the practical engineering show that calculation and analysis can be optimized by means of stiffness of side wall, modifying amplitude of moment and reducing peak value of bending moment. It is concluded that the side wall can be used as flange to calculate the ring-beam stiffness incremental coefficient.%以长沙市地铁3号线某明挖车站为研究对象,探讨盾构井环框梁在施工阶段的受力状态及优化设计方法.按承载能力极限状态进行荷载组合计算,分别应用三维立体模型和平面模型计算盾构井环框梁结构内力.对比分析三维立体模型和平面模型计算结果,结合工程经验总结认为可以通过考虑侧墙刚度、弯矩调幅、弯矩削峰的方法优化平面数值计算,并介绍考虑侧墙作为翼缘对盾构井环梁刚度增大系数的计算方法.