Analysis Of Influence Factors And Stress Features Of Bridge Piles In Cross Slopes

With the development of highway transportation,the expressway extends to the mountain area,in order to protect the mountain environment and meet the requirements of the alignment of the highway,the bridge structure is often used in the highway.However,in the face of a large number of bridge piles in the cross slope section of the mountain,there is no standard for design and calculation.Therefore,in this paper,according to the analysis of the bearing mechanism,the internal force and displacement calculation of the bridge pile foundation of the cross section of the slope,the following research work was carried out:(1)Based on the load characteristics of the bridge pile foundation in the cross slope,the bearing mechanism of pile foundation under vertical,horizontal,inclined and combined loads is analyzed.Then,the formula for calculating the lateral thrust of the pile side slope is deduced,and the calculation method and distribution law of the resistance of rock and soil on the side of pile are analyzed.(2)Through the stress analysis of the bridge pile in the cross slope section,the differential equation of the deflection of the free section,the loaded section and the embedded section of the pile is obtained and solved by the power series method.On this basis,the influence factors of different parameters on the mechanical properties were analyzed,analysis shows: when the sliding surface is shallow,the steep slope effect is remarkable,and the upper part of the pile has a large internal force and displacement;the distribution of the internal force and displacement of the pile is affected by the different distribution of the thrust,but the overall development is the same,and in the design,the results of triangle distribution are too dangerous;the reasonable design of the pile diameter can improve the internal force and displacement of the pile;the thrust of the slope and the lateral load of the pile top are positively correlated with the internal force and displacement of the pile,but the reduction coefficient of the ground resistance is negative correlated with the internal force and displacement.(3)Based on the characteristics of the double pile structure,the differential equations of flexural behavior for each characteristic section of the front and rear piles are established,andthen puts forward the calculation method of stress analysis of double pile structure in the cross slope.On this basis,the influence factors of different parameters on the mechanical properties were analyzed,analysis shows: the pile spacing is positively correlated with the horizontal displacement of the pile top and the maximum moment of the pile;the lateral thrust force of the pile side slope is positively correlated with the horizontal displacement of the pile top and the maximum bending moment of the pile;the coefficient of subgrade resistance is negatively correlated with the horizontal displacement of pile top and the maximum bending moment of the pile;the free section of the front pile is too large,will lead to “P-? effect”significantly.(4)Through the comparison between the theory and the finite element calculation results of a practical project,the reliability of the method for calculating the stress of the bridge pile foundation in cross slope is verified,and the results also show that the design is reasonable.