基于地层损失的复合地层盾构隧道施工沉降研究

盾构隧道施工诱发地面沉降的影响因素较多,但主要因素可归结为地层损失引起的地层变形。基于现有地层损失的理论,对引起地层损失的注浆过程进行模拟,依此研究复合地层盾构隧道施工对地层沉降的影响。研究结果表明:隧道贯通时,土体最大沉降和隆起区域分别位于隧道拱顶和拱底;浆液的硬化会对地表和拱顶的沉降速率产生影响,当浆液弹性模量达到最终硬化的75%时,地表和拱顶的沉降速率达到最大值并开始逐步减小;地表和拱顶沉降随浆液的逐步硬化而趋于稳定,且拱顶沉降趋于稳定的速率更快。

Shield Tunnel Settlement in Complex Strata Based on Strata Loss Theory

Among all the influential factors that cause ground settlement in shield tunneling,the strata loss is considered as the main one. Based on the existing strata loss theory,the grouting process that causes strata loss is numerically simulat-ed,to study the ground settlement in composite strata influ-enced by shield tunneling construction. The result of numerical simulation indicates that the regions with largest settlement value and uplift value are located at the top and the bottom of the tunnel respectively,and the settlement rate of ground and vault is influenced by the grout hardening. When the elastic modulus of grout reaches 75% of the ultimate hardening grout,the settlement rate of ground and vault will reach the maximum and then decrease gradually. The settlement of ground and vault tends to be stable with the grout hardening, and the settlement rate of vault is tending to a faster steady state.