Analysis On Influence Factors That High Cap Bridge Pile Foundations Under Horizontal Load Conditions In Deep Soft Soil Area

High cap group pile foundations has the characteristics of widely applicable conditions and strong ability of resistance, and it is widely used in bridge engineering in deep soft areas. But if designers lack of knowledge to the horizontal stress influence factors of bridge group pile foundation, that may be lead to too conservative designs and too high engineering cost. This paper will use three dimensional finite element software to study the influence factor of horizontal tress characteristic of high cap group pile foundation in deep soft area, take group pile foundations of one bridge in Hu-tong high speed railway as research object. And discussed the modeling method of numerical analysis of pile foundation. This paper point the applicability of the Cambridge clay model through the comparison of a variety of the constitutive models of soil. Considered the pile-soil interface mechanical properties of horizontal loaded piles to get the appropriate pile-soil interface processing method. Ensured the choosing principle of three dimensional finite element model’s Geometric boundary condition of pile foundations, which is that the size in horizontal direction should not be less than 40 times the diameter of the pile and the size in the vertical direction should not be less than 1.3times the length of the pile. This paper used the ABAQUS finite element software (which used Cambridge clay constitutive model to simulate soft soil) studied the influence patterns that the factors (such as the length, diameter, rigidity, constraint conditions, spacing of the pile and the parameters of the soil) made on high cap group pile foundation’s properties under horizontal loads, and the results showed that if the pile is only under horizontal load, the critical length of the pile is about 30times of the diameter, the best distance of the piles is about 4times of the diameter, and the rebound parameter K made a control rule to the deformation of the piles in the Cambridge clay model. At last, this paper used Taiante bridge as the object, analysis the horizontal load properties of the bridge. The result of the research could provide reference to engineering design of high cap group pile foundation that under horizontal load contions.