小净距盾构隧道开挖面稳定性研究  

Study on Stability of Small Clearance Shield Tunnel Excavation Face

作　　者：高琪 GAO Qi(The 4th engineering Co.,Ltd.,China Railway 12th Bureau Group Co.,Ltd.,710016,Xi’an,China)

机构地区：[1]中铁十二局集团有限公司第四工程有限公司,西安710016

出　　处：《城市轨道交通研究》2025年第1期103-107,共5页Urban Mass Transit

摘　　要：[目的]确定双线小净距盾构隧道施工过程中维持掌子面稳定所需极限支护压力。[方法]综合利用数值模拟、理论解析和工程验证的方法对双线小净距盾构隧道开挖面稳定性开展研究。采用数值模拟对双线小净距盾构隧道掌子面失稳模式和极限支护压力进行分析,基于数值模拟结果提出了双线盾构隧道开挖面失稳解析模型,并利用极限平衡理论推导出了维持掌子面稳定所需的极限支护压力。[结果及结论]小净距盾构隧道在施工过程中会形成联合土拱,联合土拱作用下,维持双线小净距隧道开挖面稳定所需的极限支护压力会显著增加。理论解析表明,当净距小于0.5D(D为隧道直径)时,极限支护压力随着净距增大而增大;当净距超过0.5D时,极限支护压力随着净距的增大而减小;当净距超过2.0D时,联合土拱无法形成,此时破坏模式与单洞隧道破坏模式相同,净距对极限支护压力不再产生影响。[Objective]Determine the limit support pressure required to maintain tunnel face stability during the construction of double-line small clearance shield tunnel.[Method]The excavation stability of double-line small clearance shield tunnel is studied by using a combination of numerical simulation,theoretical analysis and engineering verification.Numerical simulation is used to analyze the instability mode and limiting support pressure of double-line small clearance shield tunnel face.Based on the numerical simulation results,an analytical model for the instability of a double-line shield tunnel excavation face is proposed,and the limit support pressure required to maintain the tunnel face stability is derived by using the limit equilibrium theory.[Result&Conclusion]During the construction process of the small-clearance shield tunnel,a combined soil arch will be formed.Under the action of the combined soil arch,the limit support pressure required to maintain the stability of the double-line small-clearance tunnel excavation surface will increase significantly.Theoretical analysis shows that when the clearance is less than 0.5 D(D is the tunnel diameter),the limit support pressure increases with the increase of the clearance;when the clearance exceeds 0.5 D,the limit support pressure decreases with the increase of the clearance;when the clearance exceeds 2.0 D,the combined soil arch cannot be formed,and the failure mode in this case is the same as that of the single-hole tunnel,and the clearance no longer affects the limit support pressure.

关 键 词：地铁 双线隧道 小净距 开挖面稳定性 极限支护压力 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]