新型阻尼耗能式泥石流格栅坝的工作机制及理论计算方法

Working mechanism and theoretical calculation method of novel damping energy dissipation debris flow grille dam

为解决泥石流冲击作用下传统格栅坝容易损坏问题,提出新型阻尼耗能式泥石流格栅坝,阐述了其结构组成及工作原理。利用力法、变形协调方程与温克尔弹性地基梁理论,建立了新结构耗能与复位阶段各构件的力学计算模型,给出了立柱埋深的计算方法。运用有限元软件分析新结构的力学特性,并将理论计算与模拟值进行了对比。结果表明:(1)新型阻尼耗能式泥石流格栅坝基于柔性消能理念,通过迎流面格栅与阻尼耗能撑杆协同变形来消耗泥石流冲击能量,与传统泥石流格栅坝相比,大大提高了抗冲击性能;(2)新型阻尼耗能式泥石流格栅坝受力分耗能与复位两阶段,耗能阶段变形协调使最边跨横梁在滑移支座端内力急剧突变,设计时应着重考虑;复位阶段顶层竖杆与横梁内力大于其他层,应重点验算;(3)理论计算与有限元模拟的各构件内力变化趋势基本吻合,验证了本文计算方法的可靠性,结果可为新型阻尼耗能式泥石流格栅坝的推广应用提供理论依据。

In order to solve the problem that the traditional grille dam is easy to be damaged by the impact of debris flow,a novel Damping Energy Dissipation Debris Flow Grille Dam(DEDDFGD)is proposed,and its structural composition and working principle are interpreted.Based on the force method,deformation compatibility equation and Winkler elastic foundation beam theory,the mechanical calculation model of each component in the energy dissipation and reset stage of the novel structure is established,and the calculation method of the buried depth of the column is given.The mechanical properties of the novel structure were analyzed by finite element software,and the theoretical and simulated values were compared.The results show that:(1)The novel DEDDFGD is proposed on the basis of flexible energy dissipation concept,which consumes the impact energy of debris flow through the upstream grille and the damping energy dissipation brace.Compared with the traditional debris flow grille dam,the impact resistance power is greatly improved.(2)The force of novel DEDDFGD is divided into two stages:energy dissipation and reset.The deformation coordination in the energy dissipation stage makes the internal force of the beam between the side column and the middle column change sharply at the end of the sliding bearing,which should be considered in the design.In the reset stage,the internal force of the top vertical bar and the cross beam is greater than that of other layers,which should be checked emphatically.(3)The theoretical calculation is basically consistent with the internal force change trend of each component of the simulation,which verifies the reliability of the calculation method in this paper.The results can provide a theoretical basis for the application of the novel DEDDFGD.