大直径盾构隧道穿越复杂环境工程影响分析

Engineering Impact Analysis of Large Diameter Shield Tunnels Passing through Complex Environments

以南京市南京南隧道施工为背景,对隧道施工过程中的重大风险源—隧道上跨南京地铁S1线和宁宣高速公路机场高速路基段的施工过程开展了三维数值模拟。南京南隧道盾构直径为9m,南京南隧道与既有建构筑物交叉段要求对既有建构筑物变形控制在10mm以内,对穿越段隧道施工提出了较高的要求。数值计算结果表明:(1)南京南隧道上跨南京地铁S1线及下穿宁宣高速公路机场高速路基段主要引起的是竖向沉降,地层损失率是控制沉降的关键因素。(2)在采取一定措施后,既有建构筑物的变形均可满足相关规范的变形控制要求。

Taking the construction of Nanjing South Tunnel in Nanjing as the background,a major risk source during the tunnel construction process-the construction process of the tunnel crossing Nanjing Metro S1 Line and the Ningxuan Expressway Airport Expressway subgrade section-was simulated numerically in 3D.The diameter of the shield tunnel in Nanjing South Tunnel reaches 9m.The intersection section between Nanjing South Tunnel and existing buildings requires that the deformation of the existing buildings be controlled within 10mm,and higher requirements are put forward for the construction of the crossing section tunnel.The numerical calculation results show that:(1)The main cause of vertical settlement in the Nanjing South Tunnel crossing the S1 line of the Nanjing Metro and the high-speed roadbed section of the Ningxuan Expressway airport is the loss rate of the bottom layer,which is a key factor in controlling settlement.(2)After taking certain measures,the deformation of existing buildings can meet the deformation control requirements of relevant regulations.