基于堰流理论的泥石流堵河模型研究

Study of river-blocking due to debris flow based on weir flow theory

大规模泥石流进入主河道时,常发生堵河现象。通过分析已有的研究成果,可将泥石流堵河类型简化为3种情况,完全堵河模型、局部堵河模型和潜坝式堵河模型;从溃坝波流理论对溃坝与堰流模型相似度的分析,进而提出了用于研究泥石流堵河规律的"拟似恒定堰流模型",并建立了局部堵河和泥石流潜坝式堵河的数学方程,数值计算可得到泥石流坝前水深及坝口流速的变化规律;为验证模型的合理性,进行了室内模型实验,测定了泥石流在交汇区的堆积形态和堆积量、泥石流交汇口上游水深动态变化。实验结果表明,计算结果与实测水深曲线整体吻合度较好,理论模型对泥石流交汇初期的冲击波流考虑得还不够,但从泥石流堆积形态和堆积总量来看,假设模型是合理的。

When debris flow, which contains large quantities of stone, sand and clay particles, enters into the ma- instream, the fiver is frequently blocked. According to the results of existing research, fiver-blocking types due to debris flow can be briefly summarized into three cases, completely blocking model, partial blocking model, and submerged dam model. Based on theory of dam break wave flow, analysis results indicated that the overflow of dam breaking and weir flow are similar on the whole. A pseudo steady weir flow model to study river-blocking was pro- posed in tern, and the mathematical equations for describing the partial blocking and mudslides submerged dam were established, and by numerical calculation it can be available the change of water depth in front of the dam and overflow velocity with time. Through laboratory experiments, the morphology and volume of accumulation body of debris flow, and water depth of the main channel, were examined, the results show that calculating result is in good agreement with measured water depth curve, and the assumed model is reasonable.