地铁车站洞桩法双向开挖群洞力学效应研究  

Group-tunnel Mechanical Effect of PBA Method in Metro Stations Bidirectional Excavation

作　　者：王招兵 叱干向明 张洋 任建喜[2] 张亮[2] 张琨[2] 王蔓 WANG Zhaobing;CHIGAN Xiangming;ZHANG Yang;REN Jianxi;ZHANG Liang;ZHANG Kun;WANG Man(China Construction Third Engineering Bureau Ltd.,430070,Wuhan,China;School of Architecture and Civil Engineering,Xi’an University of Science and Technology,710054,Xi’an,China)

机构地区：[1]中建三局集团有限公司,武汉430070 [2]西安科技大学建筑与土木工程学院,西安710054

出　　处：《城市轨道交通研究》2025年第3期51-57,共7页Urban Mass Transit

基　　金：国家自然科学基金项目(11872299,12072259);陕西省自然科学基础研究计划联合基金项目(2019JLP-01)。

摘　　要：[目的]洞桩法多导洞施工所引发的群洞效应及马头门在破洞施工过程中的力学特性,对暗挖车站的施工安全构成了严重威胁。因此,有必要开展地铁车站洞桩法双向开挖过程中群洞力学效应的研究。[方法]采用FLAC3D软件,构建了洞桩法导洞施工的三维数值计算模型。通过该模型,分析了不同双向导洞施工顺序下,地面的变形规律及马头门的力学特性,并据此得出了最优的双向导洞施工顺序。[结果及结论]洞桩法双向导洞施工的群洞效应显著,且影响程度依次为:双向四导洞开挖>双向双导洞开挖>双向单导洞开挖。马头门在破洞后,其最大拉应力出现在拱底部位,而最大剪应力则发生在侧墙和拱脚。这两者的应力水平均呈现以下趋势:双向单导洞开挖<双向双导洞开挖<双向四导洞开挖。此外,马头门的最大剪应力随着开挖进尺的增加,呈现出跳跃式增大的趋势,并在施工后期逐渐趋于稳定。从改善马头门受力状态、确保破洞安全的角度来看,双向单导洞的施工顺序更为有利。[Objective]The group-tunnel effects induced by multi-pilot tunnel construction by PBA(pile-beam-arch)method and the mechanical characteristics of ingates during breakthrough excavation pose significant threats to the construction safety of underground metro stations.Thus,it is essential to investigate the group-tunnel mechanical effects in metro station bidirectional excavation process using PBA method.[Method]FLAC3D software is employed to establish a three-dimensional numerical calculation model for PBA pilot tunnel construction.Through this model,the deformation patterns of ground and the mechanical characteristics of ingates under different bidirectional pilot tunnel construction sequences are analyzed,leading to the identification of optimal bidirectional pilot tunnel construction sequence.[Result&Conclusion]The group-tunnel effects of bidirectional PBA pilot tunnel construction are significant,with the influence degree as follows:two-way four-pilot tunnel excavation>two-way double-pilot tunnel excavation>two-way single-pilot tunnel excavation.For ingates,the maximum tensile stress after breakthrough occurs at the arch bottom,while the maximum shear stress is observed at the sidewalls and arch foot.The stress levels of both go with the following trend:two-way single-pilot tunnel excavation<two-way double-pilot tunnel excavation<two-way four-pilot tunnel excavation.Additionally,the maximum shear stress of the ingate exhibits a leap-like increase with excavation progress and gradually stabilizes in the later stages of construction.From the perspective of improving the stress state of the ingates and ensuring safe breakthrough,the two-way single-pilot tunnel construction sequence is more advantageous.

关 键 词：地铁车站 洞桩法 群洞效应 数值模拟 

分 类 号：U231.4[交通运输工程—道路与铁道工程] U455.4[建筑科学—桥梁与隧道工程]