地铁上盖建筑的隔振方法对比研究

A Comparative Study on Vibration Isolation Methods of Metro Superstructure

采用有限元软件MIDAS GTS NX建立了隧道-土体-上部结构的三维有限元模型,并与实测振动数据对比,验证了计算模型的正确性。基于建立的有限元模型,探究隔振层、垫砂层和碟形弹簧支座对地铁上盖结构隔振的影响。文中以广州地铁三号线上盖的华南理工大学博学楼工程为例,分别设3种隔振方法进行对比:(1)地下室顶板位置设置高1.8 m隔振层,并在隔振层里分别填充刚性材料和柔性材料;(2)地下室底板下设置垫砂层,并以垫砂层的厚度为变量;(3)通过计算,设计合适尺寸的碟形弹簧支座,分别布置在柱底和板内。采用时程分析的直接积分法Newmark-β法进行计算,发现碟形弹簧的隔振效果最优,平均隔振率为11.23%,为地铁上盖工程提供了隔振措施的设计建议。

A three-dimensional finite element model of tunnel-soil-superstructure was established by finite element software MIDAS GTS NX.The model was verified by comparing the model results with the measured vibration data.Based on the finite element model,the effects of vibration isolation layer,cushion sand layer and disc spring support on the vibration isolation of the metro superstructure were explored.The study took Guangzhou Metro Line 3 superstructure Boxue Building of South China University of Technology as the example,three kinds of vibration isolation methods were compared:(1)set up a 1.8 m isolation layer on the basement roof and fill the rigid or flexible material in the vibration isolation layer,respectively;(2)set up a cushion sand layer at the basement floor and take the thickness of the cushion sand layer as variables;(3)design suitable disc springs through calculation,and optimize its layout,which are arranged in the bottom of the column and the slab,respectively.The direct integration method Newmark-βmethod of time history analysis was used for calculation.It finds that the disc spring has the best vibration isolation effect,and the average vibration isolation rate is 11.23%,which provides design suggestions for the vibration isolation measures of the metro superstructure.