超高性能混凝土(UHPC)包覆钢管混凝土叠合柱抗侧向冲击试验研究

Experimental Research on the Behavior of UHPC-Encased CFST Composite Columns Subjected to Lateral Impact Loading

使用超高重型落锤冲击试验系统对四根固定轴压比条件下的UHPC包覆钢管混凝土叠合柱构件进行侧向冲击试验。对冲击全过程的试件冲击力和位移响应进行了研究,对比分析了试件在不同冲击速度和不同钢管直径下冲击过程中与冲击后的损伤和失效特点。试验结果表明:UHPC包覆钢管混凝土叠合柱构件在中低速冲击下表现出弯曲破坏,仅出现少量竖向裂缝,在更高的冲击速度下UHPC未剥落,表明UHPC包覆钢管混凝土叠合柱构件优异的抗冲击性能。冲击速度的提升显著提高了构件的冲击力和位移响应,冲击耗能也随之增大。增大钢管直径能够有效提高构件的刚度,小幅度降低动态位移响应,但对冲击力响应影响不大。

A ultra-high super-heavy drop hammer impact test system was employed to conduct lateral impact tests on four UHPC-Encased CFST composite columns(UECC)with fixed axial load ratio.The impact force and displacement responses of the specimens throughout the impact process were studied,and the damage and failure characteristics of the specimens during and after impact under different impact velocities and steel tube diameters were comparatively analyzed.The experimental results showed that the UECC specimens exhibited bending failure at medium to low impact velocities,with only few vertical cracks appearing.At higher impact velocities,the outer UHPC were not spalling,indicating excellent impact resistance of the UECC.Notably,an increase in impact velocity significantly improved the impact force and displacement response of the specimens,accompanied by a proportional rise in impact energy.Furthermore,enlarging the steel tube diameter proved effective in enhancing component stiffness,marginally reducing dynamic displacement response,while exerting minimal influence on impact force responses.