Study On The Interaction Between Steep Slope And Bridge Pile Foundation Under Earthquake

With the vigorous development of domestic basic transportation construction,the application of bridge infrastructure is increasing.When constructing highways in mountainous areas with complex terrain,the form of high pier bridges along steep slopes is often used.The application of pile-pillar bridge pile foundations in mountain bridge construction widely.The pile foundation on the steep slope is affected by the upper load and the sliding thrust of the slope.The force form is more complicated than the flat pile foundation.When the earthquake occurs,the interaction between the steep slope and the bridge pile foundation is complicated,and it is more likely to cause the pile foundation to be damaged due to the instability of the steep slope.Therefore,it is necessary to analyze the dynamic response of the interaction between the steep slope and the pile foundation.The main contents and achievements of this paper are as follows:(1)Based on viscoelastic artificial boundary,a reasonable two-dimensional pile foundation model of steep slope bridge is established by finite element software ABAQUS,and the calculation formula of seismic wave input in equivalent load mode under viscoelastic artificial boundary condition is studied.Finally,the viscoelastic boundary and seismic load are added in a simpler way through the developed external program,which is verified by an example.The accuracy of theory and procedure is discussed.(2)By establishing the steep slope model under different parameters,the dynamic response of steep slopes in the presence or absence of bridge piles is analyzed.The influence of amplitude,incident angle and steep slope angle on the dynamic response of steep slopes is analyzed when there is no bridge pile foundation.The dynamic response law of steep slopes under various influencing factors is obtained.The dynamic response and stability of steep slopes are analyzed.It is concluded that the dynamic response of steep slopes is reduced when there are bridge pile foundations.,the diameter of the pile foundation and the change of the pile position will affect the stability coefficient of the steep slope.(3)By establishing pile foundation models of steep slope bridges with different parameters,the effects of wave form,amplitude,incident angle,slope angle,soil properties,bridge superstructure and pile diameter on the dynamic response of pile foundation under earthquake are analyzed,and the variation laws of pile displacement,pile lateral earth pressure and pile bending moment under different parameters are obtained: pile lateral earth pressure and pile bending moment with burial The depth increases first and thendecreases;the soil pressure and bending moment of pile side under P wave are obviously smaller than those under SV wave;with the increase of seismic wave amplitude,incident angle,slope angle and the quality of bridge superstructure,the soil pressure and bending moment of pile side increase;the analysis of different soil properties shows that the soil pressure and bending moment of pile side under soft soil are larger than those under SV wave.In hard soil,with the increase of pile diameter,the displacement of pile body and the earth pressure on pile side decrease,and the bending moment of pile body increases slightly.