基于循环交通荷载下软黏土累积塑性变形、累积孔压经验公式与分层总和法结合的方法，通过计算不排水循环累积塑性变形引起的沉降和不排水循环累积孔压消散引起的固结沉降叠加，建立了一个软土路基长期沉降拟静力计算模型。对交通荷载应力路径下的软黏土空心圆柱扭剪试验数据分析，获得了不排水累积塑性应变模型和不排水累积孔压公式的参数。基于弹性理论解积分计算交通荷载下路基中的动应力，再结合分层总和法计算了路基沉降与循环周次的关系。通过工程实例分析，对比了计算沉降结果与实测结果并与以往理论分析结果，验证了所建立模型的合理性。

The accumulated plastic strain and the pore water pressure of the soft clay under traffic loading condition were given by empirical models. Based on the layer wise summation method, a pseudo-static method is proposed to calculate the long-term settlement of the soft subgrade. The settlement is obtained by the superposition of two deformations, the one is the deformation caused by the accumulative plastic strain of the soft soil induced by undrained cyclic loading; the other one is the deformation caused by the dissipation of the accumulative pore water pressure. According to the experimental data of the dynamic hollow cylinder tests, the parameters for the empirical model of the accumulative plastic strain and pore pressure are established. The stress distribution induced by the traffic loading in soft subgrade is obtained by the integration of the elastic analytical solution; and the calculation method of the total deformation is proposed by the layer-wise summation method. The proposed method has been used in real engineering projects; its rationality is verified by comparing the calculated settlement with the field measured result and the existing solution.