Numerical estimation of landslide runout flow–structure interactions: A case study of Zhengjiamo landslide

In rural areas, landslides can bury houses and result in major disasters in affected areas, which can greatly hinder local economic development and construction. When landslides occur, sliding debris can result in large impact forces, causing varying degrees of damage to building structures. Given the great harm caused by landslides, this paper studies the prediction of dynamic response characteristics of building structures under the impact of the Zhengjiamo landslide. The engineering geological background of the Zhengjiamo landslide is analyzed in detail via field investigations. Then, a numerical method is presented to simulate the runout process of the sliding debris, and the runout process and final deposition area are studied. A node-to-surface contact algorithm is adopted to transfer the displacements and contact forces between the sliding debris and the building. The building structure is simulated via the finite element method (FEM). The sliding debris is simulated via the smoothed particle hydrodynamics (SPH) method. An element erosion algorithm is adopted to simulate the destruction process. The SPH-FEM fluid–structure coupling method is implemented to simulate the landslide dynamic disaster process (the impact behavior for the building). The destruction process is considered in the interactions between the sliding debris and the building on the three-dimensional terrain. The landslide motion during each stage is analyzed, including the sliding, energy dissipation, impact, and damage to the building structure. The maximum runout of the landslide is about 280 m. The maximum stress of the impact on the building is 2 × 10 6 Pa. The impact speed of the sliding body is generally 16.5–24.07 m/s. On the basis of this, the disaster background, disaster status, and prediction of the landslide disaster effect are studied to provide new insights into landslide disaster prevention and reduction.