Numerical modelling of flow-like landslides and the related phenomena adopting the improved Smoothed Particle Hydrodynamics (SPH) models

Flow-like landslides are a common and serious geologic hazard worldwide that can lead to substantial environmental degradation. They can severely damage infrastructure, including roads, bridges, buildings, and utility lines. Additionally, they may alter the natural landscape, cause deforestation, and contribute to soil erosion. Understanding the dynamic characteristics of this type of landslide is crucial for devising effective mitigation strategies and promoting resilience in vulnerable areas.Numerical modeling plays a crucial role in understanding, predicting, and managing flow-like landslides. It provides valuable insights into the complex dynamics of catastrophic landslide events, allowing researchers, engineers, and policymakers to assess risks, and design mitigation measures. In this PhD thesis, three challenging topics (slope failure, landslide-structure interaction (LSI) and entrainment) are thoroughly analyzed by means of numerical modelling. To investigate the first topic, I first implemented the elastic-plastic constitutive model in the DualSPHysics framework to simulate the mechanical behavior of strain history-dependent materials such as cohesive soils. Furthermore, the failure and deformation processes of a cohesive soil slope without strain softening and that of a sensitive clay slope with strain softening, are studied to validate the proposed SPH model. The multiple failure process of the Caijiapo landslide (China) was analyzed by the developed SPH model. A novel SPH model was proposed to address the second and third topics. Due to the importance of friction in the dynamic simulation of flow-like landslides, an HBP rheology model coupled with the friction dissipation was embedded into the DualSPHysics code. Regarding LSI issues, column collapse and sand flume benchmarks were carried out to verify the performance and capability of the developed SPH model. Then, the propagation of a real debris-flow event occurring in northern Italy and its interaction with check dams installed along the flow path were analyzed.