UBC Theses and Dissertations
Numerical study of landslide-generated waves Yang, Gang
This thesis describes a time-domain boundary element method to numerically simulate linear waves generated by a horizontal-moving landslide of an arbitrary profile. The approach to setting up the numerical models is based on a Green's function method and a time-stepping procedure. The numerical models include a boundary condition at the landslide surface that accounts for wave generation, a radiation condition in the far field that accounts for open water, and free surface boundary conditions in a time-stepping procedure that account for wave propagation. By solving the first-order boundary value problem in the time domain, waves generation and propagation are simulated numerically. Although the present numerical method can be applied to a variety of landslide configurations, only vertical wall with horizontal movement is considered in the present study. The corresponding numerical models in two dimensions and three dimensions are developed. The numerical models are initially used to simulate the waves generated by a piston-type wavemaker with a periodic wave paddle movement, and the results are validated against a number of analytical solutions as well as available experimental results. Specific two-dimensional landslide problems are also simulated on a horizontalmoving wall movement and comparisons of numerical results with analytical solutions have demonstrated good agreement. A number of numerical simulations on landslide-generated waves have been performed and a selection of numerical results is presented and analyzed. The results exhibit various features of interest that are discussed. Engineering curves have been developed based on the numerical results to estimate order-of-magnitude wave height caused by landslides. A case study has been carried out to demonstrate the application of numerical models. The numerical method can be applied to account for a landslide of an arbitrary shape and movement, and a water body surrounded by surfaces of various geometries. The approach and numerical models can also be extended to account for nonlinear wave effects. Overall, the numerical method and the numerical models are found to be able to provide a reasonably flexible and reliable means of studying and predicting landslidegenerated waves.
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