地铁车辆段咽喉区上盖建筑振动影响

The influence of environmental vibration from the trains in the throat area of metro depot

城区地铁车辆段进行上盖物业开发可节约、集约利用地铁用地。地铁车辆段特别是其咽喉区振动是上盖物业开发的环境制约因素。为研究地铁车辆段咽喉区对上盖建筑的振动影响,建立轨道-地基土-上盖建筑有限元模型,利用已建成上盖平台但未建上盖建筑的某地铁车辆段实测结果,验证仿真模型合理性,在此基础上,定量研究了上盖平台厚度和高度、不同结构类型上盖建筑及其层数等因素对建筑室内环境振动(铅垂向Z振级VL_(Zmax))的影响。结果表明,地铁车辆段咽喉区对高层建筑的振动影响整体大于多层建筑;由于振动波在屋顶自由端发生反射并与入射波叠加,不同楼层楼板中央VL_(Zmax)随楼层升高略有增加;框架结构建筑室内VL_(Zmax)大于剪力墙结构;增加上盖平台厚度可减小建筑室内VL_(Zmax);上盖建筑室内VL_(Zmax)随上盖平台离地高度增加而增加(即随建筑楼层绝对离地高度增加而增大)。研究结果可为地铁车辆段上盖物业开发振动污染防治提供理论和工程技术依据。

Over-track building construction in subway depots has the advantage of comprehensive utilization of land resources.The vibration caused by trains in depots,especially in throat areas,is an environmental constraint in the development of over-track buildings.To study the influence of environmental vibration from the trains in throat area,a 3D track-soil-building finite element model was established.Based on the measurement results of a metro depot over which only a vacant over-track platform was built,the rationality of the simulation model is verified.The influences of story number and structure of buildings and the influences of thickness and height of over-track platform above ground on the vibration(the maximum vertical Z-weighted VL_(Zmax))in over-track buildings were quantitatively studied.Results showed that the vibration in high-rise buildings was higher than that in multi-story buildings.The VL_(Zmax)at the center of different floor increased with the rise of building floor,which was mainly induced by the superposition of incident wave and vibration wave reflected at the free end of roof.The VL_(Zmax)of floor in frame building is higher than that in shear wall building.It decreased when the thickness of the over-track platform increased,but increased when the absolute height of floor increased.The above results can provide theoretical and engineering references for vibration pollution prevention in the development of over-track construction.