Numerical Simulation Of Mechanical Deformation Of Rock Socketed Piles Under Horizontal Loading In Red Clay Area

Laterally loaded piles embedded in rock are widely used in red clay area, but there is little research. With the development and improvement of computer technology, constitutive theory of soil and the improvement of computer performance, numerical simulation is being widely used in the research of pile group.In this paper, finite element method is used in the pile foundation and interactive characteristics of pile-soil-cap would be studied. The main work and achievements are as follows.(1) Numerical simulation is a new method, which differs from the traditional way. Based on ANSYS, three dimensional analysis of laterally loaded piles embedded in rock,which is verified by sensitivity analysis of the test results, is reliable and it provides a relatively new idea for the research of pile foundation.(2) A linear positive correlation is clearly demonstrated between horizontal resistance coefficient of soil and its elastic modulus with the regression analysis of testing data in the simple factor numerical test.(3) There is a critical pile diameter during the variation coefficient of soil with pile diameter,among which the parameter m is negatively related to the pile diameter and out of which there are fluctuations in the relationship of between parameter m and pile diameter.(4) Peak moment of rigid pile is negatively correlated with soil thickness, while flexible pile is positive. For pile group, the bending moment of rigid pile is negatively related to the soil thickness while shear force positively and internal force of flexible pile is hardly affected by soil thickness.(5) For a single pile, the internal force and displacement is mainly, significantly influenced by the diameter of pile and thickness of soil layer. For pile group, the deformation is mainly influenced by the thickness of soil layer while pile spacing, depth embedded in rock, pile diameter are secondary factors and all the factors are significant.(6) There's a critical pile spacing and the peak moment and shear force in the bottom of pile positively correlate with pile spacing within the critical value. While the peak moment and shear force in the bottom of pile are not affected by pile spacing above the critical value.(7) For a single pile, peak moment negatively correlated with pile diameter; shear forcepositively correlate with pile diameter in the soil and shear force negatively correlate with pile diameter in the bedrock. For pile group, there is a critical value in pile diameter, within which the location of peak moment goes down with the increase of pile diameter and above which the absolute value of bending moment and shear force positively correlate with pile diameter.(8) For laterally loaded pile group embedded in undulating bedrock, the plastic zone of soil mainly are distributed around pile foundation; the plastic deformation of soil before the first row of piles is the biggest; there is no any plastic change of soil around the center pile. Concrete of the back row piles is prone to crack at the interface of soil and rock and crack of the pile body is most serious. The normal stress distribution of the top section in pile group is contrary to a single pile foundation--tension is on the front while compression is on the back. The maximum bending moment is shared by the front row piles. The share of lateral load for the angular pile is the largest, followed by the middle pile on the edge, the center pile smallest. Concrete crack on the interface between soil and rock is successively transmitted forward with the degree increase of undulating bedrock. The absolute value of the peak of bending moment and shear force is negatively correlated with the degree increase of undulating bedrock.