单洪峰作用过程河道岸坡冲刷量估算方法

Estimation Method of Slope Erosion in Single Flood Peak Process

山区洪水爆发后通常会造成河流大量塌岸和岸坡失稳,单次洪峰形成过程对冲刷起重要作用。为了估算单次洪水作用过程中的冲刷量,利用山区洪水过程概化模型推导了洪峰形成过程冲刷量方程,采用粒子群算法对洪水过程概化模型参数进行拟合,取得较好的一致性,并研究了洪峰流量为600m^3/s、单洪峰作用12h过程冲刷量主要影响因素。结果发现,三角形与梯形河道断面随土体抗剪强度变化,边坡坡脚冲刷量在0.55~0.70m^3之间,随河道比降变化,边坡坡脚冲刷量在0.5~1.5m^3之间,相同条件下梯形河道断面坡脚的冲刷量低于三角形河道,河道比降参数对冲刷量的影响大于土体的抗剪强度。

A large number of bank collapses and bank slope instability will occur after the outbreak of floods,and scouring in a single flood peak process plays an important role.In order to estimate the scouring amount in the process of single flood,the scouring quantity equation of flood peak process was deduced by using the flood process hydration model.The parameters of flood process hydration model were fitted by particle swarm optimization algorithm,and good consistency was achieved.The main influencing factors of scouring amount in 12 hours process of single flood peak 600 m^3/s flow were studied.The results show that there were different types of scouring amount;With the change of soil shear strength,the scour of slope foot is between 0.55-0.70 m^3;With the change of river gradient,the scour of slope foot is between 0.5-1.5 m^3.Under the same conditions,the scour of slope foot of trapezoidal channel section is lower than that of triangular channel,and the influence of river gradient parameters on scour is greater than that of soil shear strength.