Prediction of Traffic Loading–Induced Settlement of Low-Embankment Road on Soft Subsoil: Fid-Bau Portal

Prediction of Traffic Loading–Induced Settlement of Low-Embankment Road on Soft Subsoil

Wei, Xing

AbstractPrediction of subsoil deformation under traffic loading requires honoring the dynamic nature of moving wheel loads and representing the stress path caused by such loads. A practical method in the framework of the layerwise summation procedure is proposed here for predicting the settlement of road overlaid on soft subsoil caused by traffic loading. The proposed method consists of a simplified approach for calculating the wheel load–induced stress and an empirical model for describing the accumulation of residual strain. Two amplification coefficients are introduced to account for the effect of moving speed on deviator stress and horizontal shear stress, respectively. The analytical solutions of the two amplification coefficients, which can be evaluated numerically, are deduced, and numerical results are presented in charts. Hence, the wheel load–induced stress in subsoil at different moving speeds can be calculated by multiplying the stress from a commonly used pseudostatic method with the values of the two amplification coefficients read from the charts. In addition, an empirical model is proposed for calculating the accumulation of residual strain in the subsoil under repeated heart-shaped stress cycles induced by traffic loading. The model is calibrated by simulating cyclic torsional shear tests of different clays. Providing the induced accumulated strain of the subsoil, the settlement of a road that results from traffic loading can be predicted by following the layerwise summation procedure. The performance of the proposed method is demonstrated by simulating the traffic loading–induced settlement of Saga Airport Road as an example.