Research On The Surge Height And Climbing Characteristics By Landslide In Three Gorges Reservoir Area

Landslide surge is a secondary disaster caused by the huge impact of landslide failure on the river flow.Currently,the academic research on landslide surge mainly includes the height of the initial wave,the surge attenuation law and the climbing characteristics of surge wave.To date,scholars have proposed some simplified empirical formulas to forecast the height of the initial wave and the maximum climbing height of surge wave.However,due to the incomplete parameters assessment and lack of targeted research for different river sections,the application scope of the prediction model is limited.Based on the results of the existing research,this thesis proposes an optimized prediction model through multi-factor analysis.The main research contents are as follows:(1)Based on the theories of computational fluid dynamics(CFD),the existing literature data are used for validation of using Flow-3D to analyze the landslide surge.At th same time,the grid optimize scheme of the computational region is explored by wave computational partition.combined with the Navier-Stokes equation and Tru-Volume of Fluid method,the scale model of the indoor experiment level is scaled up according to the gravity similarity criterion,and the scale effect of numerical model is investigated.(2)The formation process of landslide surges is analyzed in detail including the three stages: the landslide revival,the landslide sliding and the landslide water entry.Based on Newton's law of motion,this thesis analyzes the dynamic response between the sliding mass and the water body,and obtains the calculation model of the motion speed,including submerged landslide,partially submerged landslide and subaerial landslide.Combined with the experimental data,the validity of the velocity calculation model is verified.(3)By simplifying the landslide model in the Three Gorges reservoir area,the effect of sliding body and channel factors on the surge characteristics of trapezoidal and V-shaped channels are analyzed.Based on the numerical simulation results and the basic structure of the existing prediction model,dimensionless analysis and linear regression analysis are used to optimize the prediction model of the initial wave height and the maximum climbing height.In addition,actual landslide surge disasters were used to verify the validity of the prediction models.By comparing the results obtained by existing method and the prediction models proposed here,the accuracy of the optimized prediction model is verified.(4)Based on the landslide surge disaster prediction model of V-shaped channel,the initial wave height and the maximum climbing height after the potential landslide of Three Gorges reservoir area failed are calculated.Furthermore,combined with the digital terrain model,the grid optimization scheme and motion speed calculation model of aerial landslide,Flow-3D software is applied to examine the consequence of surge disaster.Finally,by comparing and analyzing the results of prediction model and numerical simulation,the disastrous consequence of the landslide sliding into the water is obtained.