以天津站交通枢纽工程为背景,开展考虑相互作用效应的大型土-桩-复杂结构振动台模型试验研究。文中主要对试验的相关问题进行阐述,通过对试验部分结果进行分析,初步得出土-桩-复杂结构体系的振动响应规律,检验了结构的抗震性能。试验结果表明:随着震级增加,土-桩-结构之间的相互作用影响加大,土和结构及桩的塑性发展加剧,体系的自振频率明显降低,阻尼增大,结构特别是地上结构的加速度放大系数减小较多,结构的最大应变、最大位移及最大动土压力均有所增长;加载结束,土和结构及桩均出现局部破坏现象,但地上结构最大层间位移角基本满足规范限值,说明结构坏而不倒,符合结构抗震设防的原则。
A shaking table test studying large-scale soil-pile-complex structure interaction is accomplished for the transport hub of Tianjin Station.The initial vibration response of soil-pile-complex structure is obtained,and the structure seismic performance analyzed using test data.The study indicates that with seismic magnitude increasing,the effect of soil-pile-structure interaction becomes more significant and the plasticity in soli-pile-structure develops rapidly.The natural frequency of the system decreases obviously while the damping increases and the acceleration amplification factor,especially for the ground structure,reduces significantly.At the same time,the maximum strain,maximum displacement and soil maximum dynamic pressure of the structure all become larger.At the end of the test,partial damage appears in soil-pile-complex structure and the maximum inter-story drift angles for the ground structure generally meet code requirement.There is no structure collapse but local damage,consistent with the principle of seismic structure design.