Research On Propagation Law Of Landslide Surge In Continuous Curved River

The harm caused by landslide surge can not be ignored,which has a significant impact on the safety of reservoirs,dams,wharfs and so on.Therefore,it is of great significance to study the propagation law of landslide surge in the river for the prevention and control of landslide surge disaster.In natural rivers,especially in mountainous rivers,most of them are curved and continuous.But in the existing landslide surge research,most scholars simplify the river channel as a straight river or rectangular open channel,but the actual situation shows that the propagation law of landslide surge on the straight river channel is not consistent with the propagation law of surge in the actual curved river channel.Therefore,it is one of the important directions to study the propagation law of landslide surge in continuous curved river.A large number of landslide data and literature are summarized in this paper,it analyzes the landslide and river characteristics of mountainous curved river represented by the river in the Three Gorges Reservoir area.On this basis,a generalized numerical model of landslide in continuous curved river is established,and the propagation law of hydraulic characteristics such as the propagation path of landslide surge,the maximum wave height at the midpoint of the river,the distribution of the maximum wave height of the river section,and the water level difference of the river section are analyzed by numerical simulation method.The research contents and results are as follows(1)Taking some landslides and river courses in the Three Gorges Reservoir Area as examples,the characteristics of river courses and landslides are analyzed and summarized.The research shows that the river channel where the landslide is located has the following characteristics:the river width is in the range of 500m?1050m,the turning radius is in the range of 1.2km?4km,and the turning angle is generally 30°?120°;In landslide characteristics,the average volume of landslide mass is about 6 million m~3,landslides are generally located on the right concave bank,and most of them are wading landslides..(2)On the basis of the previous chapter,a generalized numerical model of landslide surge in continuous bend is designed.The numerical model adopts VOF free surface tracking method and RNG k-model,GMO model.Compared with the literature data,the results show that the calculation method and means used in the model can better simulate the propagation of landslide surge in the river.(3)Based on the designed numerical model of continuous bend landslide surge,taking rock slope landslide as the basic type,taking landslide speed,river width and turning angle as the variable,and through orthogonal analysis of variables,the paper draws up the working conditions of continuous curved river with turning angles of 60°,90°,120°,to study the propagation law of landslide surge in continuous curved river.The results show that the width and turning angle of the continuous curved channel have an impact on the propagation of landslide surge.The larger the river width is,the faster the wave attenuation is;The smaller the turning angle is,the faster the propagation speed of landslide surge to the opposite bank is;Finally,based on the analysis of the IWHR empirical formula,the propagation coefficient of landslide surge in curved river is proposed,and the formula of landslide surge propagation along curved river is re fitted.