A Preliminary Study of the Failure Modes and Process of Landslide Dams Due to Upstream Flow

Xinghua Zhu,Jianbing Peng,Cheng Jiang,Weilong Guo

doi:10.3390/w11061115

Abstract

In the process of mineral development, large-scale flash floods (or debris flows) can be induced by the failure of landslide dams formed by the disorganized stacking of mine waste. In this study, the modes and processes of mine waste dam failures were explored using 13 experimental tests based on the field investigation of landslide dams in the Xiaoqinling gold mining area in China. Our 13 mine waste dam experiments exhibited three failure modes: (i) Piping, overtopping, and erosion; (ii) overtopping and soil collapse; and (iii) overtopping and erosion. In addition, the failure processes of the landslide dams included impoundment, seepage, overtopping, and soil erosion. Different experimental conditions would inevitably lead to different failure processes and modes, with the failure modes being primarily determined by the seepage characteristics. Overtopping was the triggering condition for dam failure. The landslide dam failure process was determined based on the particle size of the mine waste and the shape of the dam. These findings will provide a scientific reference for the prevention and mitigation of natural hazards in mining areas.

Highlights

The formation and failure of landslide dams include a series of complex processes that occur at the interface between hill slopes and alluvial plain or valley-floor systems
The debris flows in the Xiaoqinling gold mining area in Tongguan County, Shaanxi Province (Figure 1) are examples of large-scale debris flows that occurred in gullies due to the failure of mine waste landslide dams [9,10,11]
Time is a primary mechanism of landslide dam failure which occurrs after the overfilling of the dammed

Summary

Introduction

The formation and failure of landslide dams include a series of complex processes that occur at the interface between hill slopes and alluvial plain or valley-floor systems. The debris flows in the Xiaoqinling gold mining area in Tongguan County, Shaanxi Province (Figure 1) are examples of large-scale debris flows that occurred in gullies due to the failure of mine waste landslide dams [9,10,11]. The unreasonable stacking of mine waste severely blocked the gullies and formed numerous landslide dams with beaded distribution [10]. When these landslide dams failed, large-scale floods (or debris flows) occurred, such as the catastrophic disaster on 11 July 1994, which occurred when heavy rains in the upper reaches of the basin resulted in a large amount of mine waste being delivered by the flood and forming a debris flow with a peak flow rate of 260 m3 /s

Results

Discussion

Conclusion