Numerical analysis of pile foundation in huge coal silo

Composite foundation consisting of prestressed concrete pipe pile, slab, gravel cushion and soil is used in the ground treatment of coal storage silo with big diameter. It can spread most of load to the deep soil, reducing settlement and horizontal deformation of the soil. Consequently it reduces the impact on the piles of silo structure. In this paper finite element method is used to analyze the foundation. First the factors have been analyzed that have the effect on pile-soil load sharing ratio. Second the finite element model of filling pile and pipe pile foundation has been constituted and analyzed. The results indicate that pile-soil load sharing ratio increases with cap size, gravel cushion thickness and improvement of mechanical parameters of gravel cushion.