护底软体排破坏机理及应对措施

Failure mechanism of soft mattress in channel regulation project and counter measures

软体排边缘床面易受不利水流冲刷下切,当冲刷下切强度超过排体变形能力时,软体排排边会出现变形破坏。分析了护底软体排变形破坏的主要影响因素:水流条件、河床组成、软体排自身结构、余排宽度及施工工艺等。探讨了护底软体排破坏的力学机理。提出在排边一定范围内抛投一定密度的扭双工字型透水框架,能削减排边近底层的流速及紊动强度进而减弱或抑制排边冲刷,从而维持软体排结构安全及坝体稳定的应对措施。

The bed in the edge of soft mattress is easy to be scoured by unfavorable flow. When the scouring depth exceeds the deformation capacity of soft mattress, the edge of it sometimes appears deformation failure. The paper analyzes the influential factors of the deformation failure of soft mattress, which includes the flow conditions, bed composition, as well as the structure and width of soft mattress. The failure mechanism of soft mattress is also studied and corresponding counter measures are proposed. It indicates that a permeable frame of certain density can reduce the turbulent intensity near the bottom boundary flow and the bed scouring in the edge of soft mattress, which can maintain the safety of soft mattress and spur dike.