【摘要】 基于弹性波动理论,将山岭隧道洞口段简化为单面边坡模型,考虑波在洞口边坡的反射效应,推导垂直入射SH波作用下隧道轴线上的位移场分布,并将隧道简化为三维薄壁壳结构,以得到在该位移场作用下隧道结构的动力响应。针对上述分析结果开展山岭隧道洞口段振动台模型试验,以验证理论模型的合理性,并综合分析得到如下结论:将隧道结构动力响应看作横截面与纵向响应的叠加,隧道结构横截面发生剪切变形,两侧拱肩与拱脚为抗震的薄弱环节,变形效应沿轴向缓慢增加,此响应为平行隧道结构横截面传播的SH波作用所致;隧道结构纵向发生水平剪切变形,变形效应沿隧道轴向逐渐减弱,洞口处产生较大刚性位移,在施工缝存在的情况下,隧道结构在洞口附近易沿施工缝产生错台现象,此响应为沿轴向传播的SH波所致。此规律表明,隧道结构的纵向抗震设计同样值得关注。更多还原

【Abstract】 The portal section of mountain tunnels was simplified into a slope with single free face based on the theory of elastic wave. The effect of wave reflection was considered to deduce the solution of free field ground motion on the axis of tunnel under incident SH wave. The 3D shell theory was employed to provide earthquakeinduced strains. Shaking table tests were conducted for the portal section of tunnel to validate the theoretical solution. The dynamic response of lining was regarded as the superposition of the ones in cross section and in axial direction. The shearing deformation occurs in the cross section of tunnel under action of SH wave propagating parallel to the cross section. The arch spandrel and arch springing can be seen as the weak parts in seismic design of lining structure. As the distance to the tunnel portal increases, the deformation effect increases slightly. The shearing deformation occurs in longitudinal direction under the action of SH wave propagating parallel to the axial direction of tunnel. The deformation effect is gradually weakened. The dislocation occurs easily at the position of construction joint of tunnel portal due to longitudinal SH wave. Therefore the seismic design in longitudinal direction of tunnel is also worthy of consideration.更多还原