不同加载方式下的PEC柱(强轴)抗震性能试验研究

An Experimental Study on the Seismic Performance of PEC Columns(Strong Axis)Under Different Loading Patterns

基于现阶段关于PEC柱抗震性能方面研究的不足。以轴压比、钢材等级及加载方式为参数,设计制作了8个PEC柱1∶3缩尺模型并完成了低周往复加载试验。分析了试件的破坏形态、滞回耗能、承载能力、延性性能、强度退化、刚度退化等力学性能,研究结果表明:试件破坏形态为压弯破坏,滞回曲线基本呈对称的饱满梭形,具有良好的塑性变形及耗能能力。试件承载力随轴压比增加而增加,但同时也会造成延性性能变差。试件在等幅阶段多次循环及加大级差加载后的强度、刚度退化均相对稳定,承载力、耗能变化不大。单纯提高钢构件的强度并不能有效提高PEC柱的承载力,应注重钢材与混凝土的强度等级之间的匹配性,Q345钢不宜与强度等级低于C35的混凝土组合使用,为PEC柱构件在工程上的应用提供了参考。

Current research on the seismic performance of PEC(partially encased concrete)column is still limited.In this paper,using axial load ratio,steel grade and loading pattern as parameters,eight 1∶3 scale models of PEC column are designed and tested under low-cyclic reversed loading.Several indexes including failure modes,hysteretic behavior,bearing capacity,ductility performance,degradation of strength and stiffness are analyzed.Experimental results indicate that all column specimens fail in compression-bending.The hysteretic curve is basically symmetrical full spindle shaped,which indicates a good ductility performance and energy dissipation ability.With the axial load ratio increases,the strength capacity and energy dissipation capacity of the specimens increases while the ductility performance reduces.The strength and stiffness degradation of the specimens are relatively stable after repeated cyclic loading and increased differential loading at a constant amplitude stage,the bearing capacity and energy consumption have little change.Simply improving the strength of steel components cannot effectively improve the strength capacity of PEC column,and the match between the steel strength grade and concrete strength grade is more important.Q345 steel should not be combined with the concrete with a strength level lower than C35.This paper provides a reference for the engineering application of PEC column components.