新型地锚扶壁式泥石流格栅坝基础冲刷计算方法研究

泥石流格栅坝工程安全稳定的关键是基础,相比外露结构的计算,基础遭冲刷掏空的问题更值得引起重视。在提出新型地锚扶壁式泥石流格栅坝的基础上,将格栅坝基础冲刷分为初期和中后期两个阶段,初期冲刷主要以坡面冲刷为主,中后期冲刷主要考虑冲坑的变化发展。基于能量法,推导了格栅坝基础冲刷深度的计算公式,通过算例分析了不同流深下的冲刷深度,并与其它公式的计算结果做了对比。结果表明:推导公式计算的冲刷深度比其它公式计算的结果都大,初期冲刷的影响在设计中应当予以重视。

Calculation of foundation scour for new debris flow grille dam with ground anchor and counterfort

The foundation play a significant role in the reliability of debris flow grille dam. Compared with the exposed structures, foundation scour under debris flows is more important. On the basis of a new proposed debris flow grille dam with ground anchor and counterfort, the foundation scour is considered as two stages, that is, the initial and the mid-late. In the initial stage, surface scour is primary, and in the mid-late stage the changing and progressing of scour pit is important. The formula for calculating the scour depth of foundation of grille dam is deduced based on the energy method. The scour depth is analyzed under different flow depths based on an example. The results obtained from the above formula are compared with those obtained from the other formula. The results indicate that the scour depth by the deduced formula is larger than that by the others, and the initial scour should be considered carefully in the future design.