Physical model tests on landslide dam caused by rock-ice avalanches
LIU Darui1，FAN Gang1，LIN Ziyu1，LI Congjiang1，YANG Xingguo1，2，ZHOU Jiawen1，2
(1. College of Water Resource and Hydropower，Sichuan University，Chengdu，Sichuan 610065，China；2. State Key Laboratory of Hydraulics and Mountain River Engineering，Sichuan University，Chengdu，Sichuan 610065，China)
Abstract：The landslide dams formed by rock-ice avalanches are a common geological hazard in the southeastern Tibetan region of China. This study investigates the effects of ice content and spatial location of ice-rock materials on the formation morphology，dam failure process，and stability of debris dams through large-scale flume experiments. The results indicate that ice debris enhance the mobility of debris material，leading to increased blockage in the riverbed. Ice debris are influenced by particle segregation，primarily accumulating on the upper part of the landslide dams and on the opposite bank of landslide. Under the impact of water flow，ice debris within the landslide dams melt rapidly，thereby increasing the porosity of the dam body and weakening the resistance to erosion，resulting in the formation of deeper and wider breach outlets and accelerating the dam failure process. Additionally，a dimensionless stability evaluation method( ) for landslide dams containing ice is proposed. Evaluation results demonstrate a linear decrease in the stability of the landslide dam with increasing ice content.
