To study the detrimental impact of one-side surcharge load on existing piles

the force and displacement characteristics of bridge piles and piers subjected to embankment load on soft ground is discussed through an accident of bridge piles-and-piers deviation on an express highway

Zhangjiagang. According to different boundary conditions of the vertical pile-pier of existing bridge

the pile-pier applied by a side embankment load is divided into free segment

passive segment and active segment. By considering the yield of soil and the constrained boundary influence of upper structure

differential equations of bridge pile-pier are derived using tri-parameter model. A semi-analytical solution of the behaviors and deformation of bridge pile-pier is obtained using matrix transfer method. By checking calculation of the lateral deformation and bending moment of bridge pile-pier in the accident example

the applicability of the proposed solution is verified. The factors which affect the calculation results

such as the length of pile discrete element and the depth of pile passive segment

are also analyzed in the actual calculation example. The proposed method can give reference for the calculation of the response of passive piles adjacent to one side load.