可液化地基中隧道上浮的模型试验研究  

Model Experimental Study on Tunnel Uplift in Liquefiable Foundations

作　　者：李文广[1] LI Wenguang(China Railway 18th Bureau Group CO.,LTD.,Tianjin 300450,China)

机构地区：[1]中铁十八局集团第五工程有限公司,天津300450

出　　处：《防灾减灾工程学报》2024年第2期488-494,共7页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(51879090)资助。

摘　　要：地下隧道在修建过程中不可避免会穿越可液化地层,在地震作用下会发生砂土液化从而导致结构破坏。以安徽省亳州市汤王大道过河隧道工程为背景,采用室内振动台试验进行缩尺模型的设计与研究,分析地基土体与隧道结构的振动液化响应规律,研究过河隧道工程在地震液化时的上浮变形机理。结果表明:上层土体达到液化时会较下层延迟1.5 s左右,表明上部土体抗剪强度的衰减比下部土体更加明显;土体深度越大,超静孔压上升越快,且峰值越高;振动开始时由于下层土体先液化,会导致一定的向下位移,之后由于浮应力大于有效承载力导致隧道逐渐上浮并趋于稳定,当振动结束后位移的上浮量为8.9 mm。Construction of underground tunnels inevitably involves crossing liquefiable strata,which,under seismic activities,can lead to soil liquefaction and subsequent structural damage.Based on the Tangwang Avenue River-Crossing Tunnel project in Bozhou,Anhui Province,the study employed in-door shake table experiments to design and analyze a scale model.It analyzed the vibration-induced liq-uefaction response patterns of the ground soil and tunnel structure,while investigating the buoyancy-driven deformation mechanism of the river-crossing tunnel during seismic liquefaction.The results in-dicated that the upper soil layer reached liquefaction approximately 1.5 seconds later than the lower layer,showcasing a more pronounced reduction in shear strength in the upper soil.As the soil depth in-creased,the rise in excess pore pressure accelerated and its peak was higher.At the start of vibration,the initial liquefaction in the lower soil layer led to a certain downward displacement.Subsequently,as the buoyant force exceeded the effective bearing capacity,the tunnel gradually rose and stabilized.Af-ter the cessation of vibration,the tunnel uplift displacement was 8.9 mm.

关 键 词：地下隧道 砂土液化 振动台试验 上浮变形 

分 类 号：TU91[建筑科学—建筑理论]