Researching a series of problems about using steel-ash cushion to consolidate the soft clay ground,such as properties of materials,construct process,quality control and examination.

Ore cushion is simulated by filling in the pipe with gravels.

Combined with the practice of slag base construction, the characteristics of base material and the relationship with disease have been discussed.

Research on the methods to evaluate critical height of embankment on soft ground considered effect of reinforced cushion;

The design theory and method of geogrid reinforced cushion;

The testing results shows composite foundation can meet the required bearing capacity,and form "reinforced cushion" to diffuse additional stress among the "effective pile length",so the settlement becomes little;reasonable pile-soil stress ratio distribution brings the bearing capac.