Laboratory Tests and Numerical Analysis on the Grouting Reinforcement Effect for Soft-Soil Subgrade Settlement of High-Speed Railway

Grouting reinforcement is one of the most commonly used methods of subgrade treatment in soft-soil areas. In order to evaluate the grouting reinforcement effect of high-speed railway subgrade, a series of laboratory tests - such as direct shear test, compression test, and permeability test - was carried out on the Shanghai mucky clay injected with cement slurry. Based on analysis of the test results, the rational range of slurry content and water-cement ratio remain the possibility to be drawn. For the sake of further understanding the variation law of displacement, stress, and plastic zone, a series of numerical simulations was carried out on the soft soil subgrade reinforced with grouted slurry under the dynamic loading of a high-speed train. According to the results on the numerical simulation, obtaining the rational grouting scheme and grouting pressure is achievable. The research results can provide a reference for similar projects.