砂层隧道列车振动响应与地基累积变形研究

采用动力有限元数值计算方法,对列车荷载作用下狮子洋隧道典型砂层段的动力响应进行计算分析。进一步借鉴路基累积变形计算方法,对列车长期荷载作用下隧道基底砂层累积变形计算方法进行探讨。狮子洋隧道基底砂层段孔隙水压力消散较快,基底土层实际动应力比小于其临界动应力比,隧道基底砂层不会由于列车长期运营而产生局部液化破坏;在列车荷载作用下,隧道衬砌结构中应力、位移均变化不大,隧道结构在列车运营荷载作用下处于安全状态;在列车长期运营荷载作用下,隧道基底砂层累积塑性变形小于25mm,隧道基底地基土累积塑性变形不会对列车长期运营造成破坏性影响。

Study on Train Vibration Response and Cumulative Deformation of Sand Layers of the Tunnel

By use of the dynamic finite element numerical method,the dynamic responses of typical sand layers of the Shiziyang Tunnel under train loading are analyzed.The calculating method of the cumulative deformation of sand layers of the Tunnel under long-term train loading is studied with reference to the calculating method of the cumulative deformation of the subgrade.The pore water pressure in sand layers of the Shiziyang Tunnel dissipate fast,the actual dynamic stress ratio of the sand layers is less than its critical dynamic stress ratio,and partial liquefaction failures due to long-term train loading will not occur in the sand layers.Under the action of train loading,the stresses and displacements in the Tunnel lining are subjected to very small changes and the Tunnel structure remains in a safe state.The cumulative deformation of the sand layers of the Tunnel is less than 25 mm,which will not cause failures in long-term operation of the Tunnel.