自然泥石流与矿渣泥石流复合效应与防治对策

石棉县后沟是一条典型的自然泥石流和矿渣泥石流并存的泥石流沟。本文以石棉后沟为例，结合早期自然泥石流、矿产开采以来矿渣泥石流、以及2013年7 4复合型泥石流，总结了自然泥石流和矿渣泥石流的复合效应，包括泥石流物源补给的多元效应、泥石流发展演化的逆转效应、泥石流起动发生的复杂效应、泥石流动力沿程的放大效应、泥石流致灾破坏的链式效应。对照泥石流对已建防治工程的破坏，提出了自然泥石流和矿渣泥石流复合型泥石流沟防治对策，建议充分利用起动位置和物源集中补给位置的差异，加强对中上游及支沟自然泥石流起动和运动的拦挡防治，最大限度减小自然泥石流对下游矿渣防护工程的基底侵蚀和冲击破坏，从而保障综合防治工程的有效性。

STUDY ON COMBINED EFFECT OF NATURAL DEBRIS FLOW AND MINE DEBRIS FLOW AND PREVENTION COUNTERMEASURES

The Hou gully in Shimian County is a typical debris-flow gully where either natural debris flow or mine debris flow can occur. This paper is based on the investigation and analysis on the deposition characteristics of former natural debris flows in history, mine debris flows since exploitation of mineral resource in recent years and the combined debris flow occurred on July 4, 2013. The combined effect of natural debris flow and mine debris flow is summarized in the following five aspects:(1)the multi effect of the solid materials supplying for debris flow,(2)the reversal effects of debris flow development and evolution,(3)the complex effect in debris flow initiation and occurrence process,(4)the amplification effect in debris flow downstream transporting process and (5)the chain effect during debris flow damaging process. In addition, prevention countermeasures are put forward for the Hou gully debris flow at the end of this paper. It is suggested that the control works built at the middle stream for the blocking of natural debris flow can play the key role to ensure the effective and comprehensive prevention and engineering control works for preventing the mining slags at the lower stream from failure and initiation.