沟床冲刷深度是泥石流灾害防治工程设计最重要的参数之一,但到目前为止,关于黏性泥石流沟床冲刷的研究较少,沟床冲刷深度还没有权威可信的计算方法,是泥石流防治工程设计急需解决的技术问题。详细分析了黏性泥石流及可能冲刷沟床运动过程中受力情况,推导出黏性泥石流沟床最大冲刷深度计算公式。公式表明黏性泥石流沟床冲刷深度随泥石流泥深、泥石流重度和沟床纵比降及沟床堆积土体黏性的增大而增大,随沟床堆积土体内摩擦角的增大而减小。与现有计算方法相比,公式基于严格理论推导,计算结果更为精确,可用于计算已发生泥石流地区的不同频率的泥石流的冲刷深度,并举例说明了计算公式的实用价值,其结果为泥石流防治工程设计提供技术支撑。

Gully bed erosion depth is one of the most important parameters for design of debris flow control works. So far, there are few researches on gully bed erosion depth and there are no good methods for calculating the gully bed erosion depth. How to calculate the gully bed erosion depth is also a technical problem which urgently needs to be solved for debris flow preventing engineering design. The driving forces of viscous debris flow and potential resistance which may take part in the motion are analyzed. And then the calculation formula of the maximum erosion depth is obtained. The formula shows that the erosion depth of gully bed increases with the increasing of depth and density of debris flow, longitudinal slope of gully bed and viscosity of gully bed materials, while decreases with the increasing of internal frictional angle of gully bed materials. Comparing with the existing calculation methods, the formula is based on a strict theoretical derivation, the calculation result is more accurate and can be used to calculate the erosion depth in the occurrence of debris flow area for different frequencies, and provides a technical support for the design of viscous debris flow control works. The practical value of the calculation formula is illustrated.