液化场地区间隧道地震响应分析

Seismic Response Analysis of Running Tunnels in Liquefiable Site

为研究液化场地区间隧道的动力响应,利用FLAC^(3D)软件分析一致激励、局部液化和行波激励对隧道结构动力响应的影响。计算结果表明:地基土液化改变了隧道衬砌的受力状态,衬砌的破坏位置由非液化场地的拱肩和拱脚处转成了液化场地的仰拱和拱腰位置;与液化场地相比,隧道穿越局部可液化土层时,破坏位置扩展到衬砌整个断面;与一致激励相比,行波激励使衬砌的主应力增大、主应力分布改变并承受扭转作用。

To study the dynamic response of running tunnels in liquefiable site,the dynamic responses of tunnel structures under uniform excitation,local liquefaction,and traveling wave excitation were analyzed by the FLAC^(3D) software.The calculation results showed that the liquefaction of foundation soil affects the stress state of tunnel lining,and the failure position of lining changes from the arch shoulder and arch foot in non-liquefied site to the invert arch and arch waist in liquefied site.Compared with the liquefaction site,when the tunnel passes through local liquefiable soil,the failure position extends to the whole section of lining.Compared with the uniform excitation,under traveling wave excitation,the principal stress of lining increases,the distribution of principal stress changes,and the torsion effect bears.