海底隧道穿岛通风竖井地震作用下动力分析

通风竖井对隧道内的通风换气、车辆动力效应调整以及防灾救援起到至关重要的作用，是长大型隧道的重要组成部分。由于受到周围岩土的约束，海底隧道穿岛通风竖井结构的稳定性往往优于水中自立式竖井。但在地震动作用下，受周围岩土的约束及土体变形的影响，隧道通风竖井的地震响应将与普通井筒及井筒式基础存在明显差异。基于大型有限元分析软件ABAQUS建立海底隧道穿岛通风竖井结构的数值模型，考虑周围岩土及底部隧道对竖井的约束，利用时程分析法计算竖井在垂直于隧道轴向的水平地震作用下的动力响应，得出了竖井内力及位移沿深度的分布特点，通过考虑不同类型的岩土材料得到了竖井结构动力响应随场地剪切波速的变化规律。

Dynamic analysis on ventilation shaft of submarine tunnel through island under earthquake actions

As an important part of long tunnels,the ventilation shaft plays anessentialrole in the ventilation,vehicle dynamics adjustment,and disaster prevention.Due to the constraints of surrounding medium,the stability of the ventilation shaft structure of submarine tunnel through island is usually better than that of the self-supporting shaft in water.The seismic response of the ventilation shaft is significantly different from that of the ordinary shaft and shaft foundation due to the constraints of the surrounding medium and the influence of medium deformation.This study aims to analyze the dynamic response of the shaft under the horizontal earthquake actions perpendicular to the axial direction of the tunnel.A finite element model is established for the ventilation shaft of the submarine tunnel through an island using ABAQUS,and the time history analysis is presented.The constraints of the surrounding medium and the influence of the tunnel on the shaft is considered.The distribution of the internal force and displacement along depth of shaft is obtained,and the dynamic responses of the shaft with the shear wave velocity of the medium is obtained for different types of geotechnical materials.