坝后泥石流回淤坡度的模型实验研究

Model experiment on gradient of intercepted sediments of debris flow behind dam

泥石流回淤坡度是拦挡坝设计一项很重要的参数,直接影响拦截库容和工程效益。为探讨坝高以及沟床纵比降与回淤坡度的关系,选取相似比λ1为500进行模型实验。结果表明:沟床纵比降与回淤坡度呈正相关关系,不同坝高条件下,回淤坡度与沟床纵比降线性增长速率不同;坝高与回淤坡度呈二次函数关系,沟床纵比降一定,坝后回淤坡度随坝高的增大先增大后减小。

Gradient of intercepted sediments is an important parameter for design of landslide dam, which affects the intercep- ted capacity and project benefits. In order to discuss dam height, as well as the relationship between longitudinal gradient ratio of gully bed and the gradient of intercepted sediments, we conducted a model experiment by adopting a similarity ratio λL of 500. The results show that the relationship between the gradient ratio of gully bed and the gradient of intercepted sediments is positive correlatively and the derivative of linear growth of the above two parameters is quite different under various dam heights ; the dam height and gradient of intercepted sediments are in quadratic function relation, namely the gradient of intercepted sediments in- creases first and then decrease with the rising dam height if the gradient ratio of gully bed is constant.