偏压隧道半顺穿空箱挡墙设计数值分析研究

Design and Numerical Analysis of the Bias Tunnel Crossing a Half-Parallel Line Reeving Hollow Box Retaining Wall

受地层和线形诸多因素的影响,重庆国际会展中心二期市政工程下穿隧道右线不得不半顺穿空箱挡墙,且属典型地形偏压隧道。为保证隧道和空箱挡墙的稳定,采取了左洞先行开挖、右洞后续开挖、左洞台阶法以及右洞单侧壁导坑跳槽法的复杂施工方案,其计算分析非常复杂。基于新奥法施工理念,针对依托工程进行有限元模拟,分析了隧道施工过程中的围岩、支护结构以及衬砌的受力与变形规律,进而对隧道结构的安全性和围岩稳定性做出评价。分析结果表明:重庆国际会展中心二期市政工程下穿隧道采用该施工方案是合理的,可为类似隧道工程施工与设计计算提供参考。

Because of the effect Factors such as stratigraphy and linear, Chongqing International Convention and Exhibition Center under the main line of the right tunnel would have to cross a half parallel line reeving hollow box retaining wall. And it is a typical bias tunnel terrain. In order to guarantee the stability of hollow box wall, the tunnels would take to dig holes leR and right follow-up excavation hole, holes le~ France and France as well as the right step, single-hole lead pit wall switch complex law implementation plan. Its calculation and analysis is very complicated. Based on the construction theory of NAM, the author simulated 3-D FEM elasto-plastic of the construction process. The safety of the tunnel structure and stability of surrounding rock were assessed by analyzing the deformation and force of the surrounding rock and tunnel structure after digging. The results showed the construction scheme was reasonable, which could provide reference for the calculation and design of similar tunnels.