Study on interaction of soil and pile in passive state has been increasingly carried out for several years. The majority of piles are designed to support "active" loadings

however

in some cases the piles have to withstand "passive" loading

such as loads induced by lateral movement of soils surrounding the piles under ground surcharge or building construction. In this paper

reaction behaviors of passive pile and surrounding soils under surcharge applied at the ground surface are investigated respectively. Based on the compatibility condition of deformation of pile and surrounding soils

the formulae of lateral earth pressure on pile is presented. And then the partial differential equation governing deflection of pile is established and is numerically solved by combining non-linear p-y relationship curve of pile and finite difference procedure. Through an example analysis

the reasonableness and applicability of the proposed method are verified. It is shown that this simplified method will be useful in evaluating the interaction behavior of pile and soils in passive state. Comparative computations are made for different combinations of various related parameters to examine the effects of these factors on the performance of passive pile under surcharge.