Analysis of the Impact of Discrete Support on the Phase Blocking Characteristics Throughout the Granular Landslide Process

Abstract This study addresses the issue of flow state changes caused by the interaction between granular flow and barriers during landslides. A landslide model experiment was conducted to simulate the interaction process between granular flow and the barrier system, considering the slope angle and lateral blockage rate. The research explores the variation of the front speed of the granular flow over time and the changes in flow state. Additionally, simulations are performed using PFC3D discrete element software to examine the trend of the average flow velocity throughout the landslide process and briefly analyze the phase change degree of the granular flow at the barrier position. The results indicate that the overall trend of the front speed of the granular flow is continuously increasing, with a notable change point at 0.2 seconds that distinguishes the effects of slope angle. The interaction between the granular flow and the barrier system leads to splitting and flow direction deviation, which collectively weakens their energy. Under a single variable, the average flow velocity of the granular flow is inversely proportional to the lateral blockage rate and directly proportional to the slope angle, with the barrier system having a significant impact on the average flow velocity. For the first row of barriers, the attenuation of the total average speed of the granular flow increases with higher slope angles and lateral blockage rates. For the second row of barriers, the attention of the total average speed of the granular flow also shows a proportional relationship with the lateral blockage rate. The research findings provide valuable references for the prevention and control of debris flow and landslide disasters, the interaction mechanisms between granular flow and barriers, and related engineering applications.