叠落盾构隧道受力分析及管片配筋

摘要

在现代城市轨道交通建设中,上下叠落地铁盾构隧道越来越多,这类叠落盾构隧道相互影响,塌落拱多次叠加,传统解析法计算隧道围岩压力存在困难,目前缺乏相应的叠落隧道围岩应力计算方法.为了研究叠落盾构隧道受力分析及管片配筋,以北京地铁6号线南锣鼓巷站—东四站叠落盾构隧道为工程实例,根据弹塑性理论模拟隧道开挖过程计算塌落拱多次叠加,结合强度折减法计算叠落隧道塑性区,然后根据塑性区计算塌落拱高度和围岩压力;根据厚壁圆筒理论,计算盾构施工和列车运营对下方隧道附加应力;根据以上分析,计算叠落隧道的下方盾构隧道管片内力并配筋.%In the construction of modern urban rail transit,more and more overlapping subway shield tunnels are used.The overlapping shield tunnels are interacted with each other.The collapse arch of overlapping tunnels is multiple superposed during digging.The traditional analytical method is difficult to calculate the pressure of tunnel surrounding rock.At present,there is no effective way to calculate the stress of overlapping tunnel surrounding rock.In order to study the stress and the segments reinforcement of overlapping shield tunnels,this paper takes the overlapping shield tunnels in Nanluoguxiang station to Dongsi station of Beijing Metro Line 6 as an example.The arch collapse multiple superposed is calculated by simulation of tunnels excavation process using the elastic-plastic theory.The plastic zone area of the tunnels is calculated using the strength reduction method.Then the collapse arch height and surrounding rock pressure are calculated from the plastic zone area.According to the theory of thick wall cylinder,the additional stress of the lower tunnel by shell in construction and by train in running is calculated.From above analysis,the internal force of overlapping shield tunnels is calculated and the segments reinforcement of lower shield tunnel segment is designed.