Vol15 No.10: 2247-2265
【Title】Long runout mechanism of the Shenzhen 2015 landslide: insights from a two-phase flow viewpoint
【Author】QIAO Cheng1,2,3,4; OU Guo-qiang1,2; PAN Hua-li1,2*; OUYANG Chao-jun1,2; JIA Yang1,2,3
【Addresses】1 Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China; 2 Key Laboratory of Mountain Surface Process and Hazards, Chinese Academy of Sciences, Chengdu 610041, China; 3 University of Chinese Academy of Sciences, Beijing 100049, China; 4 Anhui University of Science & Technology, Huainan 232001, China
【Corresponding author】PAN Hua-li
【Citation】Qiao C, Ou GQ, Pan HL, et al. (2018) Long runout mechanism of the Shenzhen 2015 landslide: insights from a two-phase flow viewpoint. Journal of Mountain Science 15(10). https://doi.org/s11629-017-4595-5
【Abstract】A catastrophic landslide occurred at Hongao dumpsite in Guangming New District of Shenzhen, South China, on December 20, 2015. An estimated total volume of 2.73×106 m3 of construction spoils was mobilized during this event. The landslide traveled a long distance on a low-relief terrain. The affected area was approximately 1100 m in length and 630 m in width. This landslide made 33 buildings destroyed, 73 people died and 4 people lost. Due to the special dumping history and other factors, soil in this landfill is of high initial water content. To identify the major factors that attribute to the long runout character, a two-phase flow model of Iverson and George was used to simulate the dynamics of this landslide. The influence of initial hydraulic permeability, initial dilatancy, and earth pressure coefficient was examined through numerical simulations. We found that pore pressure has the most significant effect on the dynamic characteristics of Shenzhen landslides. Average pore pressure ratio of the whole basal surface was used to evaluate the degree of liquefaction for the sliding material. The evolution and influence factors of this ratio were analyzed based on the computational results. An exponential function was proposed to fit the evolution curve of the average pore pressure ratio, which can be used as a reasonable and simplified evaluation of the pore pressure. This fitting function can be utilized to improve the single-phase flow model.
【Keywords】Dynamics; Landslide; Long runout; Pore pressure; Two-phase