滚石冲击荷载下垫层材料的动力响应研究  

Research on Dynamic Response of Cushion under Rockfall Impact

作　　者：向波 何思明[2] 庄卫林[1] 王东坡[2] 

机构地区：[1]四川省交通运输厅公路规划勘察设计研究院,四川成都610041 [2]中国科学院水利部成都山地灾害与环境研究所,四川成都610041

出　　处：《公路交通科技》2015年第1期45-49,56,共6页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(41272346);国家科技支撑计划资助项目(2011BAK12B03)

摘　　要：棚洞垫层结构能有效地耗散滚石冲击能量,大幅度降低滚石冲击力,是滚石防护棚洞设计的关键参数。本文以Hertz接触理论为基础,考虑棚洞土垫层的弹塑性特性,运用动力有限元数值仿真技术,研究了滚石法向冲击荷载下耗能垫层结构,分析了滚石冲击速度、半径对垫层土体动力响应规律的影响,为棚洞垫层结构优化设计提供理论依据。计算结果表明:按照完全弹性理论计算过高地估计了滚石冲击力;滚石冲击能量主要转化为土垫层的塑性变形;土石垫层结构能有效地吸收滚石冲击能量,大大降低滚石对棚洞结构的冲击力。The cushion of rock shed can effectively dissipate impact energy and greatly reduce impact force of roekfall, which is the key parameter for optimal designing of rockfall protection. Considering the elastic- plastic property of the cushion materials, based on the Hertz contact theory and using the dynamic finite element numerical simulation technology, we studied the energy dissipation cushion structures under rockfall normal impact load, then we analyzed the effect of impact velocity and radius of rockfall on dynamical response of cushion, which provides a theoretical basis for structure optimization design of cushion of rock shed. The calculation result shows that （ 1 ） the value of impact force calculated by complete elastic theory is overestimated; （2） the impact energy is mainly converted to plastic deformation of soil cushion; （3） the cushion structure can effectively absorb the impact energy of rockfall and greatly reduce the rockfall impact load on the rock shed.

关 键 词：道路工程 动力响应 数值模拟 滚石 法向冲击 弹塑性 回弹 

分 类 号：TU435[建筑科学—岩土工程]