缓冲器对钢筋混凝土桥墩撞击性能影响的试验研究

采用落锤冲击实验装置,进行钢筋混凝土桥墩模型在侧向撞击荷载下的动力性能试验,研究在桥墩模型表面设置缓冲器对试件撞击动力响应的影响.比较了不同缓冲器的缓冲效果,分析了影响桥墩模型冲击裂缝扩展和破坏模式的主要因素,研究了冲击能量和试件峰值动力响应及撞击体平均冲击力的关系.试验证明,所设置的缓冲器可以较大程度地减少构件的冲击动力响应,对撞击区受压钢筋峰值压应变可降低74.60%,受压混凝土峰值压应变可降低54.69%,受拉钢筋峰值拉应变可降低63.02%,跨中峰值位移可降低57.73%,抗开裂冲击能增加180%,撞击体的平均冲击力可降低78.59%.研究结果表明,经合理设计的缓冲器具有高效的缓冲作用,可用以提高桥墩的抗撞能力.

Experimental Research on Effect of Buffer on Impact Performance of Reinforced Concrete Pier

The dynamic performance test of reinforced concrete bridge pier model under lateral impact loading was conducted by falling-weight impact equipment to study the action of buffer installed on pier surface on the impact dynamic response of specimen. The buffer effects of different buffers were compared. The main factors that influence the crack propagation and failure pattern of pier under impact load were analyzed. The relation of impact energy with peak dynamic response of specimen and mean impact force was researched. The experimental result proves that the buffers installed can reduce the impact dynamic response of specimen greatly: the peak strain of compressive reinforcement can be decreased by 74.60%, the peak strain of compressive concrete can be decreased by 54.69%, the peak strain of tensile reinforcement can be decreased by 63.02%, the peak deflection at mid-span can be decreased by 57.73%, the anti-crack impact energy can be increased by 180%, the mean impact force of impact body can be decreased by 78.59%. The research result demonstrates that the buffer action of the reasonably designed buffer is effective enough to increase the anti-crash capacity of pier.