复杂结构-桩-土振动台模型试验数据分析

Data analysis of shaking table test studying complex structure-pile-soil interaction

本文从分析复杂结构-桩-土振动台模型试验数据入手,用加速度动力系数、最大位移、最大正应变、最大动土压力等指标对结构的地震响应全面分析,并对比桩、地下结构、地上结构的不同响应,研究发现:结构不同部分最大地震响应发生的频率不尽相同,且受地震动频谱特性及自身频率影响,天津波加载时结构的地震响应较大;地表以下,当震级较小时,土-结构对地震动起放大作用,随着震级的增加,对地震动放大作用减缓甚至减小;最大位移随结构高度增加逐渐增大,在桩与地下结构交界处和地表处,位移改变较大;地下结构柱、桩最大正应变呈中间大、两头小分布;最大动土压力随着深度增加呈两头大、中间小分布,且地表处最大;总的土压力受最大动土压力影响较大,随深度增加有先降低、后增大的趋势。

Based on the data analysis of the shaking table test studying complex structure-pile-soil interaction,this paper analyzes fully the earthquake responses of structures by using acceleration dynamic coefficient,maximum deformation,maximum normal strain and maximum dynamic soil pressure.It is found that the frequencies inducing the maximum earthquake responses in different parts of the structure are different.The responses are also influenced by the spectral characteristics of seismic ground motion and its vibration frequency.The earthquake responses are drastic when the Tianjin seismic ground motion is applied.The amplification of the seismic ground motiomn by soil-structure is big when the magnitude is small,while it reduces when the magnitude increases.The maximum deformation becomes bigger when the structure height increases,and it changes obviously at the interface between the pile and the underground structure and at the surface of soil.The maximum normal strain of the column of underground structure is big in the middle but is small at both ends.The maximum dynamic soil pressure is big at both ends but small in the middle,when the soil depth increases and the maximum dynamic soil pressure occurs at the soil surface.The total soil pressure is affected obviously by the maximum dynamic pressure.It decreases first and then increases when the depth increases.