竖向地震作用下浅埋地下结构中柱的动力响应

Dynamic response of middle post of shallow buried underground structure under vertical seismic excitation

利用结构动力学方法对浅埋双跨地下结构中柱在竖向地震作用下的动力响应进行了研究。为了简化分析,首先将地下结构看作刚体,利用刚体与地基的相互作用分析得到刚体在竖向地震分量作用下的动力响应。随后,由于双跨地下结构为对称结构,取其一半进行分析,由于考虑到侧墙对于顶板的弹性约束作用,使用抗弯弹簧代替。根据边界条件,将之前的刚体动力响应作为输入,可以求得顶板的弯矩和剪力,进而求得中柱的受力情况。结果表明,竖向地震分量对中柱的作用是显著的,甚至会对地下结构中柱产生严重的破坏。研究为分析中柱的变形与破坏奠定了基础,可供地下结构的动力分析和设计参考。

This paper studies the dynamic response of shallow buried double-span underground structure mid - pillar under vertical seismic excitation using structural dynamics methods. In order to simplify the analysis, we take the structure as rigid body and the dynamic response of structure under vertical seismic excitation was obtained by analyzing the interaction between rigid body and foundation. Then half of the structure is taken into consideration because of the symmetry of the structure. Bending restraint of side wall was taken into consideration by bending spring. Bending moments and shear forces of roof slab was gotten by inputting the dynamic response of the rigid body obtained previously as boundary condition of roof slab, and the stress of middle post was obtained. The results show that the effect of vertical seismic excitation on the middle post is significant, even cause serious damage of the middle post. This research can serve as a basis for analysis of deformation and fracture of the middle post, and provide a reference for dynamic analysis and design of the underground structure.