中文摘要：

通过在棚洞支座处设置金属耗能器代替传统砂石垫层,吸收滚石冲击能量,可最大程度减小滚石冲击力。常用的金属耗能器存在初始屈服荷载远高于平均压垮荷载的缺陷。为此,提出一种新型带初始损伤的金属耗能器,通过降低其初始屈服荷载,达到优化棚洞工程的目的。基于LS-DYNA研究轴向冲击荷载下不同初始损伤模式金属耗能器的动力响应,比较了其破坏模式、冲击力-位移关系与耗能效果。结果表明：合理的初始损伤设置可有效降低金属耗能器初始屈服荷载达40%;而平均压垮荷载、吸收的总能量基本保持不变,研究成果可为金属耗能器在棚洞工程中的应用提供依据。

英文摘要：

New-typed structurally dissipating rock-shed can maximum decrease rock-fall impact force and reduce engineering investment by installing metal shock absorbers. Traditional energy absorber has a peak yield load which is much larger than average post buckling load,thus the rock-shed RC slab is requested a larger shock resistance and higher investment. A new metal energy absorber with initial damage is proposed to reduce the maximum load while maintaining the effect of energy absorption. The dynamic response of metal absorbers with different initial damage modes under axial impact is studied by LS-DYNA,failure modes,force-displacement response and energy dissipation are compared. Results show that,reasonable initial damage can effectively reduce peak yield load up to40%,while average collapse load,total energy absorption remain basically unchanged,thus the metal energy absorber is optimized.