地铁隧道盾构下穿既有隧道的数值模拟

Numerical Simulation on Metro Shield Tunneling Crossing below the Existing Tunnel

随着城市轨道交通的快速发展,新建隧道施工临近既有已运营隧道的情况越来越多。以某工程中新建盾构隧道下穿既有已运营隧道为背景,运用大型有限元软件ABAQUS对盾构下穿施工过程进行了模拟,分析了既有隧道的应力和位移以及不同地层损失、不同覆土厚度和隧道间距对既有隧道的影响。结果表明:新建隧道盾构下穿施工使既有隧道的应力分布发生变化,并使既有隧道产生向着新建隧道的位移,最大位移发生在新建隧道下穿位置;地层损失、覆土厚度、隧道间距对既有隧道沉降的影响较大,在设计、施工过程中应引起足够的重视。

With the rapid development of rail transit, more and more new tunnels are built nearby the existing tunnel that has been operating. Shield tunneling construction process is simulated for the new metro tunnel below existing tunnel of certain project by large finite element software ABAQUS to analyze the stress and displacement of existing tunnel, and the impact of different strata loss, different overburden thickness and tunnel spacing on the existing tunnel. The results show that when the new tunnel is constructed, the stress distribution of the existing tunnel changes, and the existing tunnel displaces toward the new tunnel, maximum displacement appear in the intercrossing position of the new tunnel, and strata loss, overburden thickness and tunnel spacing have great influence on the settlement of the existing tunnel, to which enough attention should be paid.