SPH-based simulation of flow process of a landslide at Hongao landfill in China

Landfills are the most popular means of disposing of construction solid waste owing to the low-cost, large treatment volume and strong adaptability. However, landfill collapses and landslides are common, posing a risk to lives and property. A catastrophic landslide, not triggered by heavy rainfall or earthquakes, occurred on December 20, 2015, at Hongao landfill in Guangming New district of Shenzhen, China. The collapsed waste soil flowed 1100 m down a slope with an elevation difference of 100 m. This catastrophic landslide is typical of long-runout disasters with high mobility, which result in great loss to life and property. In this paper, we focused on reproducing the flow processes and simulating the arriving area of the landslide at Hongao landfill using a full three-dimensional (3D) smoothed particle hydrodynamics (SPH) method. A series of undrained ring shear tests were conducted to determine the viscosity coefficient for the numerical simulation. The calculated geometry of the landslide using the full 3D SPH method agreed well with the field data. Hence, the combination of ring shear tests and SPH method can be widely used to predict the dynamic behavior of potential landslides in landfills, to reduce or prevent similar disasters.