Research on Subgrade Differential Settlement Control Standard and Treatment Technology Based on Driving Comfort

At present, the geogrid is commonly used to treat the differential settlement of the subgrade at the joint of the filling and excavation effectively. In order to further improve the utilization rate of geogrid in the treatment of subgrade, the driving comfort index was proposed innovatively to control the subgrade differential settlement. Based on the human-vehicle-road coupling system model, the influence of subgrade differential settlement area, subsidence value, and vehicle speed on the maximum vertical acceleration of the human body was analyzed. The correlation between the vertical acceleration of the human body under different vehicle speeds and the differential settlement value was obtained through multiple regression calculations, and the subgrade differential settlement control standard based on driving comfort was proposed. By establishing the finite element model of the cut to fill subgrade, the characteristics of differential settlement at the top surface of the subgrade under different geogrid laying positions, densities, and lengths were calculated and analyzed. In addition, the differential settlement layout scheme of the geogrid disposal subgrade based on driving comfort was proposed, and the effectiveness of the scheme was verified by experiments. The results show that the position and length of the grid are the main factors affecting the treatment effect of the vertical and horizontal cut to fill subgrade. The proposed layout scheme can effectively control the differential settlement of the subgrade and raise the utilization rate of the geogrid. The research results can provide theoretical value and reference for the laying of geogrid in mountainous roads