Study On Interaction Mechanism And Parameters Between Horizontally Loaded Pile And Rock And Soil Around Pile In High And Steep Slope Area

In the process of pile foundation design,the proportional coefficient of horizontal resistance coefficient of foundation soil has always been a very important parameter.At present,the reference value of the value given by the relevant codes in China comes from the summary of the pile foundation based on the static load test on the horizontal site.There is little research on the value of the foundation in the high and steep slope area.Therefore,taking the pile foundation project of a super large bridge in Southwest China as the background,this paper has carried out a reduced scale indoor physical model test and numerical test to study the relevant influencing factors of horizontal loaded pile value in high and steep slope area and the interaction mechanism between pile and soil.The main research contents and main results are as follows:(1)According to the actual engineering background,carry out the proportion test of model materials,prepare model materials with different proportions,determine the uniaxial compressive strength of materials through uniaxial compression test,and determine its cohesion and friction angle through direct shear test,and select the appropriate proportion.The section bending stiffness of the model pile is calculated by the inverse flexibility algorithm.In order to facilitate the application of horizontal load,a self-designed and processed loading device is adopted to provide the necessary foundation for the subsequent indoor model test of horizontally loaded piles.(2)Through the indoor physical model test,the horizontal static load test is carried out on the pile foundation at five different positions on the slope,and the influence of the different positions of the pile foundation on the high and steep slope(slope toe position,slope position and slope edge position)on the proportional coefficient of the horizontal resistance coefficient and the horizontal ultimate bearing capacity of the foundation is studied.The distribution law of the horizontal resistance of the slope pile foundation is obtained,and the internal force of the pile body is analyzed.The results show that the bending moment of the pile increases first and then decreases with the increase of the buried depth of the pile;The value decreases with the increase of pile foundation position parameters;Under the same slope inclination,the horizontal bearing capacity of foundation pile in high and steep slope area is related to its location parameters,and the horizontal ultimate bearing capacity decreases as the location parameters of pile foundation increase.(3)The three-dimensional numerical model of high and steep slope is established,and the horizontal loaded pile foundation at different positions of high and steep slope is numerically simulated.The influence of load on horizontal loaded pile is analyzed from three aspects: pile top displacement,pile bending moment and soil pressure around pile;Draw the gradient relationship curve between horizontal force and pile top displacement,and then obtain the comprehensive value of pile foundation at different positions.Carry out regression analysis on the curve,and find the linear fitting function of pile position parameters and values.(4)The numerical simulation of horizontal loaded pile on slope is carried out by changing slope inclination,pile diameter and pile length,and the effects of the above three factors on the value and horizontal ultimate bearing capacity are analyzed.The simulation results show that with the increase of slope inclination,the horizontal ultimate bearing capacity shows a downward trend as a whole,and the critical load also shows a downward trend as a whole;With the increase of slope angle,the value decreases gradually;The value increases with the increase of pile diameter and pile length,which changes nonlinearly.The research in this paper shows that the different positions of pile foundation on the slope will affect the value and the horizontal ultimate bearing capacity of pile foundation,and the linear fitting function between the position parameters and the value of pile foundation is obtained,which can provide a reference basis for the value of the median value in the design process of pile foundation on high and steep slopes in Southwest China.