盾构隧道横断面地震响应分析

Transverse Seismic Response Analysis of Shield Tunnel

随着盾构法在隧道施工中越来越广泛的应用,盾构隧道横断面抗震性能的研究日益受到业界关注。以武汉长江隧道为例,对土体采用D-P本构模型,盾构隧道结构采用梁-弹簧模型,建立盾构隧道横断面二维模型进行动力有限元计算,该模型顶部采用自由边界,侧面采用自由场边界,底部采用静态边界。选用0.1g的天津波和场地人工波作为激励,研究了盾构隧道结构的加速度、变形和内力响应。结果表明:盾构隧道的拱顶与拱底的加速度响应大于隧道左侧、右侧;隧道拱底的绝对位移响应最大;地震作用对隧道衬砌结构的内力增量较为明显。目前的隧道结构设计可以满足结构抗震性能要求。

Along with the wider application of shield in tunnel construction,the seismic behavior of shield tunnel draws increasing attention from researchers.In this paper,The D-P constitutive model was employed to simulate the model soil,and beam-spring was used to simulate the shield tunnel.A two-dimensional finite element model,which considered the property of infinite half space and could effectively simulate the dynamic soil-structure interaction,is established.The response of acceleration,deformation and internal force is studied under the 0.1g Tianjin wave and the site artificial wave.The calculated results show that the acceleration response at bottom and top is greater than that at left and right of the tunnel.Absolute displacement response at tunnel bottom is the maximum.The inner force increases sharply when the seismic loads were exerted. The computational result indicates that the seismic performance of the shield tunnel can satisfy the request of earthquake resistance.