The law of landslide surge propagation and the affects of flow field surrounding a pipeline

Large landslide instability will throw rock and soil into the water, causing massive surge waves, damaging the underwater pipeline structure, and endangering the lives and property of coastal residents. This study uses the RNGκ-ε turbulence model and the VOF method to numerically simulate the landslide surge based on the physical experiment model. This paper simulated the characteristics of the surge generated by the sliding block entering the water, analyzed the time history changes of the free surface, the factors influencing the surge height, and the flow field characteristics around the pipeline. According to the simulation results, the maximum surge height has a nonlinear increasing law with entry velocity, entry angle, and slider volume and a nonlinear decreasing law with water depth. At the back of the pipeline, the first collision between the forward-advancing surge and the reflected reflux surge will create a collision zone. Until the water surface is stagnant and gone, the collision zone will travel forward due to the rise in reflux water velocity and backwards due to the secondary wave produced by the surge. The simulation results corroborate the findings of physical experiments, which can provide technical assistance in protecting underwater pipelines, ensuring people's livelihoods, and maintaining urban public safety. •The evolution of free liquid surface with time and the interaction of the four factors are confirmed by physical experiments.•The impact surge law on the flow field surrounding the pipeline was analyzed.•It can offer technical assistance for safeguarding undersea pipes, assuring people's livelihoods, and preserving public safety.