摘要
以某超长大型步行天桥的抗震分析为例,在上部结构分析中引入了地基基础刚度。采用弹性时程和弹塑性时程等方法分析比较了固定约束、线性弹簧约束、非线性弹簧约束等不同模型在地震下的响应。计算表明引入基础刚度后,上部结构的动力特性发生变化,柱分担的地震剪力比例上升,墙的比例下降。在大震弹塑性时程分析中,基础的非线性变形起到了耗能作用,削弱了上部结构的地震响应。
Foundation stiffness was introduced to the seismic design of a large pedestrian bridge in this paper.Three hypotheses,the fixed constrain,the linear spring constrain,and the nonlinear spring constrain,were adopted to study seismic performances of the bridge using both linear and non-linear time-history analyses. The results show that by introducing foundation stiffness, the dynamic characteristics of the bridge change significantly. The bridge columns carry larger proportion of earthquake shear forces,while those carried by seismic walls endure decrease. In nonlinear time-history analyses under rare earthquakes,nonlinear foundation springs exhibit strong hysteretic behaviors and reduce the seismic responses of the upper-structure.
出处
《结构工程师》
北大核心
2015年第5期77-83,共7页
Structural Engineers
关键词
超长结构
基础刚度
非线性时程分析
步行天桥
抗震设计
overlong structure
foundation stiffness
nonlinear time history analysis
pedestrian bridge
seismic analysis
