The Numerical Simulation Of Landslide Generated Waves And Analysis Of Wave Characteristics

The landslide generated waves refer to the waves caused by the sudden sliding of rock and soil on the slope and the interaction with the water body.It is a secondary hazard with greater harm and will pose a major threat to the safety of people's lives and property.Over the years,various scholars have conducted a lot of researches on the problem of landslide generated waves,but due to the complexity of its influencing factors and action mechanism,there are still many problems that need to be solved urgently.In order to carry out the numerical simulation of the landslide generated waves' process and study the characteristics of the landslide generated waves,this paper combines the relevant physical model tests and engineering examples to model and numerically simulate the whole process of landslide generated waves,and quantitatively study the water waves' characteristics.The main contents include:(1)The mathematical simulation tool FLOW-3D is used to establish the mathematical model of the rigid landslide generated waves,and the calculation result is compared with the physical model test to verify the validity of the model.(2)The numerical simulation of the waves induced by the deformable landslide is carried out,the characteristics of the maximum wave height and runup of the waves are displayed and analyzed,and the difference between the waves caused by the rigid body and the deformable landslide body is discussed.(3)Using the methods of range analysis based on orthogonal test design and scale analysis,the influence degree of waves' many influencing factors is quantified and compared,and several main influencing factors of landslide generated waves are determined.(4)Quantitative analysis of the near-field and far-field water waves' characteristics is performed,the energy ratio between the first wave and the total energy of the waves in near field is determined,the far field waves meet the linear water waves' standard,and the waves' frequency and dispersion characteristics are studied;The characteristic parameters are used to define the judgment conditions of the waves' type,and the quantitative range of the near field and the far field is given;the energy conversion rate of the landslide to the water body is calculated.The research results show that:(1)The numerical simulation carried out in this paper can accurately capture the movement characteristics of the landslide body and the characteristics of the induced waves,and the simulation results are consistent with the physical model test results.(2)The difference in the degree of the landslide's deformation caused by the difference in the porosity of the landslide has a small effect on the characteristics of the caused waves,rigid body has slightly increased wave height and runup caused by slipping into water compared with deformable landslide.(3)The three main factors affecting the landslide generated waves'characteristics are the dimensionless landslide volume Vw*,the dimensionless landslide underwater motion time ts*,and the Fr sin ? that characterizes the initial water entry velocity of the landslide and the bank slope angle.(4)The energy ratio between the first wave and the total energy of the waves in near field can reach nearly 80%;the far field waves meets the linear wave standard and propagates at an approximate long wave velocity(?);the type of the landslide generated waves can be determined by the underwater motion time of the landslide t0;The starting point of the far field is approximately located in 3.25 times of the water depth;the energy conversion rate of the landslide to the water is approximately 3.0%.