摘要
我国西部山区地形复杂,存在诸多高陡边坡,因此落石灾害时有发生,已严重威胁公路交通安全及人民生命安全。棚洞结构在落石灾害防治中起到了重要作用,但落石冲击棚洞的动力响应过程十分复杂,尤其是落石与棚洞的瞬态接触过程,然而目前国内外学者对于落石冲击问题的研究仍不够完善。为深入研究落石冲击下棚洞结构的动力响应特征,通过建立相应的ANSYS/LS-DYNA有限元模型,分别对落石质量、落石形状、落石下落高度及落石冲击角度4种不同工况下的棚洞结构动力响应过程进行了模拟研究。对不同工况下的冲击力时程曲线、冲击深度时程曲线和Mises等效动应力时程曲线等模拟结果进行了分析。结果表明:冲击力、冲击深度、棚顶Mises等效动应力与落石质量、下落高度呈正相关;在法向方向上,冲击力、冲击深度与冲击角度呈正相关,在切向方向上,45°时冲击所产生的冲击力最大,冲击深度与冲击角度呈负相关;长方体落石和立方体落石所产生的冲击力和棚顶Mises等效动应力大于球体落石,而冲击深度小于球体落石。
The mountainous terrain in western China is complicated and there are many high and steep slopes.Therefore,rockfall disasters occur from time to time,which has seriously threatened the safety of highway traffic and the lives of people.The shed-tunnel structure plays an important role in the prevention and control of rockfall disasters,but the dynamic response process of rockfall impacting shed-tunnel structure is very complicated,especially the transient contact response between rockfall and shed-tunnel structure.However,the research on rockfall impact is inadequate at home and abroad.In order to study the dynamic response characteristics of shed-tunnel structure under rockfall impact,the dynamic response process of shed-tunnel structure under 4 working conditions,e.g.,rockfall mass,rockfall shape,falling height and the impact angle,are simulated with the established ANSYS/LS-DYNA FE model.The time-history curves of the impact force,penetration depth and Mises equivalent dynamic stress under different working conditions are analysed.The result shows that(1)the impact force,penetration depth and Mises equivalent dynamic stress of the shed-tunnel structure are positively correlated with rockfall mass and falling height;(2)the impact force and penetration depth in normal direction all increase with the impact angle,while the impact force is the largest at 45°and the penetration depth is negatively correlated with the impact angle in the tangential direction;(3)when the shape of the rock block is cuboid and cube respectively,the impact force and Mises equivalent dynamic stress of the shed-tunnel structure are larger than those of the sphere rockfall,but the penetration depth is less.
作者
柏雪松
李俊峰
祁小博
陈红旗
刘红岩
BAI Xue-song;LI Jun-feng;QI Xiao-bo;CHEN Hong-qi;LIU Hong-yan(China Water Northeastern Investigation,Design&Research Co.,Ltd.,Changchun Jilin 130021,China;China Institute for Geo-environmental Monitoring,Beijing 100081,China;School of Engineering&Technology,China University of Geosciences(Beijing),Beijing 100083,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2020年第8期73-80,共8页
Journal of Highway and Transportation Research and Development
基金
国家级地质灾害应急防治项目(2019)
国家重点研发计划项目(2019YFC1509701)
四川省自然资源科技计划项目(KJ-2018-23)。
关键词
隧道工程
动力响应
数值模拟
落石
冲击力
tunnel engineering
dynamic response
numerical simulation
rockfall
impact force
