土-承台动力相互作用对砂土场地桩基桥梁地震反应的影响

Influence of Soil-Base Slab Dynamic Interaction on Seismic Response of Pile Foundation Bridges in Sandy Soil Site

在桩基桥梁的地震反应分析中,桩-土动力相互作用是个重要的问题,而对于采用低桩承台基础的桥梁,承台埋在土面以下,还存在土与承台之间的动力相互作用。目前,地震反应分析中一般不考虑土-承台动力相互作用的影响,相关研究也很少。为此,利用OpenSees有限元分析程序,基于p-y曲线建立了土-结构一体化桩基单墩模型,选择40条实际岩石场地地震记录作为输入,开展了考虑土-承台动力相互作用的桩基桥梁地震反应分析。结果表明,考虑土-承台动力相互作用后,结构的基本周期会减小,墩底曲率会明显增大,桩顶曲率会大幅减小,但墩顶位移的减小可以忽略。

Soil-pile dynamic interaction is an important issue in the seismic response analysis of pile foundation bridges.For a bridge with the low-pile base slab foundation,the base slab is buried below the earth surface,and there is also dynamic interaction between soil and base slab.At present,the influence of soil-base slab dynamic interaction is generally not considered in seismic response analysis,and is rarely studied in the literature.Therefore,based on the p-y curve method,a soil-structure integrated pile foundation single-pier model is established by using OpenSees finite element analytical procedure.40 actual rock site seismograms are selected as input to carry out the seismic response analysis of pile-supported bridge considering the soil-base slab dynamic interaction.The results show that the basic period of structure will decrease after considering the soil-base slab dynamic interaction,and the curvature of pier-bottom section will obviously increase and the curvature of pile-head section will greatly decrease,but decrease of displacement at the pier top can be neglected.