长距离叠落段盾构隧道施工影响叠加效应分析

Analysis of the Influence of Shield Tunnels Construction on the Superimposed Effect in Long Distance Overlapping Section

受隧道侧上方苏州桥的桥桩位置限制,北京地铁16号线万寿寺站—苏州桥站区间盾构隧道左、右线呈叠落形式布置。因此采用有限元数值模拟方法,研究了区间隧道3个典型叠落段的盾构掘进叠加效应。计算结果表明:左、右线隧道完全叠落段施工对地层扰动的叠加效应最明显,且上下层隧道净距越小,叠加效应越显著;完全叠落段的上层隧道施工将会引起下层盾构隧道管片结构上浮。该数值模拟计算结果为制定土体注浆加固措施及下层隧道内的加固方案提供了依据。

Restricted by the piles position of Suzhou bridge above the tunnels,the left and right lines of shield tunneling between Wanshou Temple Station and Suzhou Bridge Station of Beijing Subway Line 16 were arranged in the form of overlapping.By using finite element numerical simulation method,the superimposed effect of three typical overlapping sections of tunnel construction are studied.The results show that the construction in completely overlapping sections influenced the superimposed effect on soil disturbance most obviously;The smaller the distance between upper and lower tunnels,the more significant the superposition effect;The construction of the upper tunnel in the overlapping section will cause the segment structure of lower shield tunnel to rise.The results of numerical simulation provide basis for making the reinforcement measures of soil grouting and the reinforcement scheme in t lower tunnel.