地下结构反应位移法的两种简化分析途径及应用

Two simplified analysis processing and their application of underground structure seismic deformation method

通过反应位移法以及基于地层-结构模型施加加速度或强制位移的简化分析途径分别计算一个双跨箱形地下结构在地震荷载作用下的结构内力,并用时程分析法对计算结果进行校核。结果表明:各方法所得结果相近,均能较好体现地下结构动力响应特征;在我国,由于缺乏完整的速度反应谱、地层峰值位移等参数,且地层弹簧刚度的计算繁琐使得反应位移法未推广应用;反应位移法的两种简化分析途径采用地层-结构模型,省略地层弹簧刚度的取值,提高了计算效率;简化途径中,施加地层加速度时建议模型侧边距取3倍以上结构跨度,施加强制位移时侧边距取1倍结构跨度。

The seismic internal force of a double-span rectangular underground structure was calculated with dynamic time history method and seismic deformation method as well as two simplified analysis processing of seismic deformation method, which used ground-structure composite model with ground acceleration or enforced deformation applied. The calculation results show that： these results are close to each other and can reasonably reflect the dynamic response properties of underground structures; the seismic deformation method has not been popularized in China because of the inadequate study of ground motion parameters such as velocity response spectrum and peak deformation of ground as well as the tedious calculation of ground spring stiffness; the simplified analysis processing are more efficient because of the using of ground-structure composite model which omits the calculation of ground spring stiffness ; the proper width between structure and ground boundary is 1 time outer span of structure and more than 3 times span of structure in enforced deformation applied and ground acceleration applied cases respectively.