泥石流巨石冲击下的钢构格栅坝动力响应分析

泥石流中的巨石冲击是造成拦挡结构破坏的最直接因素,因此设置钢构格栅坝拦截大石块,对减小泥石流冲击破坏有十分重要的作用。本文就钢构格栅坝结构模型,利用国际通用计算动力荷载的非线性有限元软件ANSYS/LSDYNA进行数值模拟。用钢球模拟巨石,分别在格栅坝中间榀顶层梁柱节点和中间榀顶层柱中部施加冲击荷载,分析在冲击荷载作用下结构的动力响应。结果表明：作用在结构上的冲击力大小与被冲击构件刚度大小密切相关,被冲击构件刚度越大,结构受到的冲击力越大,反之,冲击力越小;钢构格栅坝在冲击作用下,冲击作用部位、结构支座部位及梁柱节点部位响应较大,设计时应予以加强;且钢构格栅坝不同位置遭受冲击作用时结构响应完全不同,与冲击力作用在梁柱节点时相比较,冲击力作用在构件中部时结构整体响应明显较小。该结果为泥石流拦挡工程中钢构格栅坝的设计提供了参考。

Dynamic response analysis of steel grille dam under the impact of big stones in debris flow

The impact of big stones in debris flow is the most direct factor that cause dam structure damage, so setting steel grille dam to block big stones has very important effect to reduce the debris flow impact damage. In this paper, the author use the international general computing power load of nonlinear finite element software ANSYS/ LS-DYNA to simulate structural model of steel grille dam. Steel balls was used to simulate the stone, impact load is respectively settled in the top-level beam-column joints on the middle of the grille dam and in the intermediate cross of the column on the middle of the grille dam, analysis the dynamic response of structure under the shock load. Results show that the impact force on structure has a close relationship with the rigidity of the dam itself, the greater the rigidity of the dam is, the bigger the impact load is, on the contrary, the smaller the rigidity of the dam is, the smaller the impact load is; under the action of impact force, the response is bigger on the location of impact parts, support of the structure and beam-column node, dam structure should be strengthened when designed; and impact force performed at different location of the steel grille dam cause structural response of the dam completely different, compared with the impact effect at the location of beam-column joints, impact effect on middle of the component can produce significantly smaller overall response. The research results provide reference information for the design of steel grille dam in debris flow block engineering.