Traffic-load-induced Cumulative Settlement of Soft Clay Subgrade of Low Road Embankment

Based on the undrained cumulative deformation model and the cumulative pore pressure model of the soft clay presented by Huang and employing the static and dynamic finite difference method,the cumulative settlement of Shanghai soft clay subgrade was computed and analyzed.Results show that the cumulative settlement consists of the undrained cumulative deformation and the deformation due to the dissipation of cumulative pore pressure,however,the former is principal.The cumulative settlement increases sharply with time in initial open stages of traffic and then gradually tends to stable state.When the road embankment is less than 1.5 m height,the cumulative settlement increases rapidly with the decrease of the road embankment height.The more vehicle load is,the more sharply cumulative settlement increases.When the overload ratio is 0.2,the increase ratio of the cumulative settlement is 44%.So overload limiting is critical to control the cumulative settlement.The presented formulas of the cumulative settlement prediction can well reflect the effects of road embankment height and vehicle loads.