岩石河床在冲击水流脉动压力作用下的解体破坏机理  

Mechanism of disintegration of rocky riverbed under the action of fluctuating pressure due to impinging jet

作　　者：李爱华[1] 刘沛清[1] 

机构地区：[1]北京航空航天大学教育部流体力学重点实验室,北京100083

出　　处：《水利学报》2007年第11期1324-1328,共5页Journal of Hydraulic Engineering

基　　金：国家自然基金重点资助项目(50539060);国家自然基金面上资助项目(10772015)

摘　　要：考虑高坝下游岩石河床的裂隙结构特性,分析河床岩体解体破坏以及冲坑形成的物理机理。根据经验公式和理论推导给出动态河床上脉动压强的分布规律,基于河床逐层破坏假定,应用蒙特卡洛方法模拟生成基岩仿真一维裂隙网络,沿各网络裂隙线元建立一维瞬变流模型,对高坝下游冲击射流作用下非恒定脉动压力波在复杂裂隙网络内的传播过程进行数值模拟。应用孤立块体逐层自动追踪方法,分析裂隙岩体的解体破坏机理、孤立岩块的瞬时动力力学特性以及岩石河床的逐层破坏过程,提出岩块稳定性判据以及冲坑极限深度的评估方法。The mechanism of disintegration of rocky riverbed due to impinging jet downstream of high dam is analyzed. The riverbed is assumed to be eroded from layer to layer and the distribution of fluctuating pressure acting on the riverbed due to jet impact obeys the law given by the empirical formula. By applying the Monte - Carlo method the crack network in rock can be generated and the propagation of the transient flow in crack network under the action of jet impact is simulated. On this basis, by using the automatic tracing method the disintegration process of the cracked layered rock can be simulated based on the analysis of dynamic forces acting on the discrete blocks. Furthermore, the method for judging the stability of rock block and formula for predicting the ultimate scouring depth are proposed.

关 键 词：冲击射流 脉动压力 裂隙网络 瞬变流模型 

分 类 号：TV653[水利工程—水利水电工程]