可液化地基中隧道上浮的模型试验研究?

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。

Model Experimental Study on Tunnel Uplift in Liquefiable Foundati

Construction of underground tunnels inevitably involves crossing liquefiable strata, which,under seismic activities, can lead to soil liquefaction and subsequent structural damage. Based on theTangwang Avenue River-Crossing Tunnel project in Bozhou, Anhui Province, the study employed indoorshake table experiments to design and analyze a scale model. It analyzed the vibration-induced liquefactionresponse patterns of the ground soil and tunnel structure, while investigating the buoyancydrivendeformation mechanism of the river-crossing tunnel during seismic liquefaction. The results indicatedthat the upper soil layer reached liquefaction approximately 1.5 seconds later than the lowerlayer, showcasing a more pronounced reduction in shear strength in the upper soil. As the soil depth increased,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, asthe buoyant force exceeded the effective bearing capacity, the tunnel gradually rose and stabilized. Afterthe cessation of vibration, the tunnel uplift displacement was 8.9 mm.