Dynamic Characteristics Analysis Of The Abutment-pile-soilInteraction Under The Vehicle Loads

As a kind of important basic form because of its high strength, great bearing capacity and fine durability, pile foundations have been widely used in abutment base. It mainly supported dynamic action of vehicle load whose the characteristics were low intensity, long action time and the unfixed vibration frequency. These dynamic actions are overlooked easily, but it can produce more effect than the vehicle static. It is prone to distortion at the abutment which can affect the smooth of the vehicle running and buried hidden on traffic accident. Dynamic characteristics analysis of the abutment-pile-soil interaction under the vehicle loads is extremely complex, there are still many problems has not been completely resolved at present. So it is a significant engineering practical value to study on the regular of abutment-pile-soil dynamic response under vehicle loads next to the Abutment.In view of the above problems, the author discusses the dynamic characteristics of the soil, on the basis of previous research results, through the dynamic triaxial test obtained the important parameter of soil dynamic interaction; Based on the soil Drukle-Plager model, Introducing the contact virtual thickness factor to the abutment-pile-soil dynamic interaction; By the finite element software MIDAS/GTS, analysis the pile-soil stress and deformation under different conditions, To study the effects of different factors on the interaction between pile and soil;Simplifying the vehicle dynamic load,Established the abutment pile soil finite element model, improved the boundary condition, Put forward the elastic damping boundary conditions, which suitable for dynamic analysis; Considering the vibration characteristics of the structure to build the finite element model, under the vehicle dynamic load Research the deformation and the stress of the abutment-pile-soil, Revealed the variation of the maximum displacement and the stress; Comparative analysis the effects of different factors on the abutment-pile-soil interaction, and the following conclusions are obtained:(1) Constructing the abutment-pile-soil finite element model considering the elastic damping boundary conditions and the structure of its vibration characteristics, it can better expression the deformation process of abutment-pile-soil under the vehicle loads.(2)In the analusis of the pile-soil interaction,the normal stiffness reasonable mangnitude of the contact surface is 106kPa and the visual thickness factor can successfully simplify the contact setting.(3) Driving speed, axle load and position are the three main factors influencing the interaction of abutment-pile-soil, by taking them into consideration, the most dangerous driving position is got, simultaneously, the interrelations of maximum deformation and stress with them are also analysed.(4) Pile diameter, pile length and pile space are also the main factors influencing the interaction of abutment-pile-soil, by calculation under different working conditions, the laws between them are obtained.