Evaluation of Differential Settlement of Subgrade for Highway-Widening Projects

Highway widening is an important way to improve the existing expressway capacity and promote development of transportation systems. The differential settlement between old new subgrade key factor evaluate whether it necessary carry out ground improvement for foundation, which will cause longitudinal pavement cracking even instability. Therefore, most critical task in highway expansion project controlling settlement, particularly post-construction settlement. In this study, a fluid-structure coupling analysis model was developed based on FLAC3D, modified Cam-clay (MCC) used describe difference foundation parameters. working conditions different heights groundwater levels were simulated analyze their influence during after construction. With increment value transverse slope (Δi) maximum (k) curves as evaluation indexes, size widened under evaluated, provides basis design engineering suggestions reinforcement measures should be taken. results show that increases with increase level height. Under requirement Δi ≤ 0.5%, not take condition local water 2 m height −9 −11 4 However, when rises further, or measures. Meanwhile, k taken all regardless research can provide theoretical reference treatment roadbed-widening engineering.