为了揭示单侧边载对既有工程桩的不利影响，结合张家港某高速公路枢纽高架桥基桩-立柱偏移事故的工程实例，分析了路基边载作用下软土地基桥梁桩柱的位移特征和受力机制；根据桥梁桩柱沿竖向受力模式的不同，将边载作用下桥梁桩柱划分为自由段、被动受荷段和主动作用段；在此基础上，考虑到地基塑性屈服和上部结构约束边界的影响，基于三参数地基模型，建立了桥梁基桩-立柱受力响应的微分控制方程，并通过矩阵传递法给出了半解析解答。通过对工程实例中2排桩柱水平位移和受力弯矩的验算，验证了计算方法的适用性，并通过算例分析了桩身离散单元长度、被动段深度对计算结果的影响规律，结果可为单侧边载作用下被动桩受力响应的计算分析提供参考。

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.