尾矿库渗流溃坝模型实验研究

渗流破坏是尾矿库溃坝的重要诱导因素之一,但目前针对渗流破坏对尾矿库溃坝影响的研究还比较少,因此本文以云南某尾矿库为工程背景,采用自制的尾矿库溃坝实验装置,开展尾矿库室内堆(溃)坝模型实验研究,分析在渗流破坏情况下尾矿库溃坝过程、溃口发展、下泄泥砂沉积规律。结果表明：空隙中的可动颗粒被渗出水流带走,造成初始渗流通道建立并扩大,坝肩中部出现“砂流溢出”和“沼泽化”现象；随着坝体集中渗流通道的扩展,出渗点位置上部饱和坝体在自重作用下发生沉降和垮塌,并向上游呈牵引式发展,随后库内水流漫过坝顶垮塌部分的最低点,导致溃口的形成,坝体破坏模式由逆向牵引破坏向溢流侵蚀破坏转变；溃口的发展主要是由溃坝水流对坝体的掏蚀、冲刷所造成,在溃坝的不同时刻溃口发展是不同的,初中期以下切为主,后期为横向展宽以主；由于水流的分选作用,下泄泥砂在坝体下游的沉积随演进距离的增加,表现出由粗到细的规律,且不同位置出现了粒径的分级现象。以上研究成果能为矿山的防灾减灾提供理论基础。

Experimental Study on Dam Break Model of Seepage in TailingsReservoir

The seepage failure is one of the important induction factors for dam-break in the tailings reservoir. However, there are still few studies on the effect of seepage failure on the dam-breaking of the tailings reservoir. Therefore, Based on the engineering background of a tailings repository in Yunnan, a self-designed tailing reservoir dam-breaking experimental device was used to carry out experimental research, and to analyze the dam-breaking process of the tailings reservoir, the development of the dam burst, and the sediment deposition under the seepage failure. The results show that: Movable particles in the voids are taken away by the permeated water flow, causing the initial percolation channels to build up and expand, forming a concentrated flow channel, and the overflow and swamping occurred at the dam overflow point. With the expansion of the concentrated seepage passage of the dam body, the saturated dam at the upper part of the outfall point will settle and collapse under the action of its own weight, and the upstream dam body will develop into a traction type, and then the water flow in the reservoir will reach the lowest point of the collapsed part of the dam roof, and lead to the formation of a breach, the dam failure mode of dam collapse from reverse traction damage to overflow erosion damage.The development of the breach is mainly caused by the erosion of the dam-breaking water flow. At different times of the dam-break, the development of the breach is different. On the early and middle stages, the development of the breach are mainly below the cut, and the later it is the horizontal broadening.Due to the sorting effect of water flow, the deposition of silt in the lower reaches of the dam body increases with the evolution distance, showing a coarse-to-fine sedimentary rule, and a grading phenomenon of particle size appears at different positions.