近断层竖向速度脉冲地震作用对RC柱抗剪性能的影响

以单个RC柱为分析对象,采用台湾集集地震中3组断层距18条速度脉冲型地震动记录,通过非线性动力时程分析,研究断层距、竖向与水平加速度谱值比、柱初始轴压比、竖向和水平振动周期以及剪跨比对RC柱抗剪性能的影响规律。结果表明:近断层竖向速度脉冲地震作用对RC柱的抗剪性能有很大影响;抗剪性能系数随反应谱比值增大而减小,中等初始轴压比与断层距、以及剪跨比与近断层距(0～10km)对柱抗剪性能有交互作用。最后,对结果进行非线性回归分析,建立了考虑近断层竖向速度脉冲地震效应及其影响因素交互作用的抗剪性能系数表达式。

Shear resistant performance of RC columns subjected to vertical near-fault velocity pulse-like earthquake actions

Single RC columns are used to investigate the influence of fault distance, vertical and horizontal acceleration spectral ratio, initial axial load ratio, fundamental period and shear span ratio on shear resistant behavior of RC columns. Eighteen-velocity pulse-like earthquake records divided into three-fault distance from Chi-Chi earthquake are used as excitations to execute nonlinear dynamic time history analysis. The results demonstrate that axial velocity pulse-like earthquake action has evident effects on the shear resistant performance of RC columns. Shear-resistant behavior factor decreases with the increase of spectral ratio, and medium initial axial load ratio and fault distance, shear span ratio and near fault distance (0~10 km) have coupling influence on the shear-resistant behavior of RC columns. Finally, nonlinear regression analysis of analytical data in the present study is carried out and empirical approach considering different effect of these factors is proposed.