【摘要】 针对地铁建设中典型的马蹄形断面隧道建立比例尺为1∶20的分析模型,并采用数值分析方法研究马蹄形隧道处于单一土层及工程所处区域典型的成层土体中时的动力响应。分析结果表明,在单一土层中由于土体的约束作用,结构产生的位移以整体沉降为主,在成层土体中除产生一定的整体变形外还伴随一定的扭转变形。在两种地层情况下马蹄形地铁隧道在地震动力作用下的动力加速度响应、竖向位移均在拱顶处产生最大值,其中在单一土层中的加速度响应最大值为结构中部加速度的2.29倍。结构在顶部和侧板处所产生的动应力响应值也较大。研究表明,地震动力荷载作用下顶板、侧板均为受力较大部位,在设计和施工中应予以充分重视。更多还原

【Abstract】 A model is set up by the similarity theory as 1/20 of the horseshoe shape metro tunnel.The dynamical response of the model that the tunnel locates in the single soil layer and typical soil layers and affects the earthquake activities is analyzed by the numerical software.The results show that when the tunnel is excavated in the single soil layer,the vertical displacement is similar as settlement.When the tunnel is located at the typical soil layers,there are torsions as well as the settlement.No matter which kind of site the tunnel is,the maximum values of the acceleration,vertical displacement both are got at the top of the tunnel.In the signal layer soil the maximum acceleration is 2.29 times of that at the middle side slab of the tunnel.The principle and shear stresses at the top and side slab of the tunnel are bigger than which those at other points.These show that the top and the side slab are the place which affect the strong force when there are earthquake activities.Some measurement should be taken in these points in the tunnel design.更多还原