摘要
[目的]白云岩地层中溶洞隐伏多,易造成塌方和涌水。为确保施工安全,须基于溶洞分布情况研究白云岩地层地铁盾构施工的动态力学变化特征,分析对盾构施工过程中影响。[方法]以贵阳地铁3号线皂角井站—太慈桥站区间为工程依托,通过PFC^(3D)6.0离散元软件与FLAC^(3D)6.0有限差分软件耦合,建立盾构隧道三维离散-连续精细化数值模型,进而研究不同溶洞分布对盾构隧道施工的影响。首先,盾构机土仓内的渣土采用滚阻接触本构,并通过数值验证确定其对应的细观参数;其次,分析盾构施工过程中地层的变形规律,获得了盾构机的刀盘扭矩、推力及土仓压力的力学分布特征;最后,进一步研究了不同溶洞水平间距和空间分布下盾构隧道施工的动态力学变化特征。[结果及结论]刀盘的切削方向对地面的沉降有一定影响,盾构施工对开挖面前方5 m范围内的土体有显著影响。最大地面沉降出现在靠近溶洞的一侧。当溶洞位于开挖面下方时,盾构机在自重作用下有栽头的风险。
[Objective]Dolomite strata contain numerous concealed karst caves,which easily lead to collapse and water inrush.To ensure construction safety,it is necessary to study the dynamic mechanics variation characteristics of metro shield construction in dolomite strata based on karst cave distribution,and analyze their influence during shield construction.[Method]Using the interval between Zaojiaojing Station and Taiciqiao Station on Guiyang Metro Line 3 as the engineering case,a three-dimensional discrete-continuous refined numerical model of a shield tunnel is established by coupling the PFC^(3D)6.0 discrete element software with the FLAC^(3D)6.0 finite difference software,aiming to investigate the influence of different karst cave distributions on shield tunnel construction.First,the muck in the shield machine soil chamber is modeled using a rolling-resistance contact constitutive relation,and its corresponding mesoscopic parameters are determined through numerical verification.Second,the deformation patterns of the stratum during shield construction are analyzed,and the mechanical distribution characteristics of the cutterhead torque,thrust,and chamber pressure are obtained.Finally,the dynamic mechanical variation characteristics of shield tunnel construction under different horizontal spacings and spatial distributions of karst caves are further examined.[Result&Conclusion]Due to the influence of the cutterhead cutting direction on land subsidence,shield construction has a significant effect on the soil within 5 meters ahead of the excavation face.The maximum land subsidence occurs on the side closer to the karst cave.When the karst cave is located beneath the excavationface,the shield machine is at risk of nose-diving under its self-weight.
作者
齐明山
王祥
刘琛尧
晏启祥
QI Mingshan;WANG Xiang;LIU Chenyao;YAN Qixiang(Shanghai Urban Construction Design and Research Institute(Group)Co.,Ltd.,200125,Shanghai,China;GuiyangPublic Transport Investment and Operation Group Co.,Ltd.,550081,Guiyang,China;Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,610031,Chengdu,China;China Construc-tion Silk Road Transportation Construction Investment Co.,Ltd.,611100,Chengdu,China)
出处
《城市轨道交通研究》
北大核心
2026年第1期61-66,共6页
Urban Mass Transit
基金
国家自然科学基金项目(52278416)。
关键词
地铁
盾构隧道
白云岩地层
离散-连续耦合模型
掘进参数
溶洞分布
metro
shield tunnel
dolomite strata
discrete-continuous coupling model
excavation parameters
cave dis-tribution
