Study on New Technology of Treatment of Capillary Water in Subgrade with Soft Permeable Pipe Filled with Sand

The technique took into account the high underground water level silty soil with stronger capillarity, subgrade soil easy water softened in Yellow River flood plain areas. It seriously affected the stability of subgrade. If lay a layer of gravel cushion in the ground, and then buried soft permeable pipes in the lower part of embankment, the permeable pipes filled with sand, the top of pipes sealed with geotextile, it would form the vertical drainage channel for the capillary water. So capillary water would along the vertical drainage channels formed by sand core soft permeable pipe and horizontal drainage channels formed by gravel cushion flowed out of the subgrade. The reliability of the method is verified by seep/w module in GEO-studio. This technique could effectively improve the strength and stability of subgrade, reduce the adverse effects of capillary water on the roadbed.