Research Of The Force On The Pile Caused By Landslide Surge

The surge generated by landslide is a secondary disaster,will be seriously affected the safety of sailing,restricted navigation,destroyed downstream residents housing,farmland,roads,etc,and destroy the hydraulic structures,leading to instability.The pile is widely used in aquatic building such as bridge and dock.The impact force on the pile brought by landslide surge is crucial to the stability and safety of the whole aquatic building.On the basis of physical model experiment and numerical simulation calculation,this paper considers the characteristics of the force on the pile under the action of landslide surge.The main conclusions are as follows:(1)Based on the physical test data,study on the variation of dynamic pressure along the time of pile,the characteristics of time variation,influencing factors and rules are analyzed.Under the same condition of the first wave,the similarities and differences of the dynamic pressure of the pile under the action of the surge,the regular and the solitary waves are analyzed.The stepwise regression analysis method is used to select the influencing factors,the formula for calculating the extreme value of dynamic water pressure of pile is obtained.The power function is the highest degree of fitting formula of extreme value,and the value of dynamic hydraulic pressure of the pile is clear and definite.(2)The numerical simulation software Flow3D was used to simulate the landslide surge,and on the basis of physical model test,the total force of the pile structure is analyzed by adding sliding velocity v and jumbo size slider.Analyze the free surface variation of numerical flume at different time visually,x-y and x-z plane flow field characteristics,hydrostatic wave pressure and total force of pile,and analyze the variation law of the total force on the pile along the time and its influence factors.(3)The variation characteristics of dynamic water pressure and total force of the pile are similar,the forward extreme value appears in the moment when the surge spreads to the pile,then a reverse extreme value is generated,later both values fluctuate and decay in a small range.When the size of the slider and the sliding speed is certain.will produce the volume surge,this part of the surge carries most of the energy,the extreme value of the dynamic water pressure and the total force are also produced by this energy.