【摘要】 通过动力方程的推导,提出在地下结构抗震分析中,位移时程输入可能是更好的选择.在此基础上,考虑多种因素,建立了三维地下综合管廊有限元模型,分析了其在地震作用下的响应特性.研究发现,在轴向地震动输入情况下,结构出现整体弯曲变形.另外边界以及接触面条件对结构应变影响较大.在结构考虑为弹性的情况下,自由边界较无限单元情况下的结构应变幅值明显偏小,相对误差最大可达123.3%,当不考虑土体与结构之间的相对滑移时,结构的应变增大幅度可以达1/3之多.最后对行波效应的影响进行了探讨.更多还原

【Abstract】 The displacement time history input is recommanded for the seismic analysis of underground structures based on the deduction of the dynamic equation.A three-dimensional finite element model of the utility tunnel with a consideration of many effects is established for the seismic analysis.The results reveal that the utility tunnel exhibits global bending deformation pattern under shear wave excitation.On the other hand,the effects of the boundary and the contact condition are significant to the structural strain.On the assumption that the structure is elastic,the strain amplitude of the free boundary condition is rather lower compared to the infinite element boundary condition,and the maximum relative error can reach 123.3%.When the slippage between the soil and structure is not considered,the structural strain amplitude can increase about 1/3.Finally,the paper presents a study of the influence of wave passage effect.更多还原