Abstract: In order to determine the technical program and technical parameters for stabilizing collapsible loess of subgrade treatment in west of Liaoning, some experimental research of stabilizing subgrade, such as, dynamic compaction, impact-rolling and lime soil pile, has been carried out. Combining insitu test with laboratory experiment, the physical and mechanical properties in experimental areas are compared before and after treatment, and some conclusions are drawn out such as：(1) It is effective to treat 4 m to 6 m in depth under 800 kN·m to 1 600 kN·m in compaction energy without with not less than 8 tamper times；(2) Lime soil pile is suitable to improve subgrade with thick loess, which can dispel the loess collapisibility either in the range of pile length or in a certain extent from pile end；(3) The method of impact-rolling is useful to treat loess with the less thickness of the layer and topsoil with about 1m in depth, and impact rolling is optimal in 40 times. The result mentioned above provided a technical references for collapsible loess sudgrade treatment in this area.

Key words: collapsibe loess, subgrade treatment, dynamic compaction, impact-rolling, lime soil pile