Abstract: The CementFly AshGravel (CFG) Column method is an effective soil improvement method and it has new developments. The new procedures, such as, allspiralflightauger drilling and pumping the filling material inside the borehole, have the characteristics of low construction noise, fast column installation, and cost effective. Under the adverse and complicated geological conditions, these new techniques have made special contributions in a safe and successful CFG column installation. This paper presents a case history of the application of CFG columns in improving the liquefiable soils for Huxian East Station in the Xi'an Chengdu passenger rail project. The excessive filling ratio of the CFG column under the adverse geological conditions is analyzed and factors affecting the filling ratio are presented. The mitigation measures that control the filling ratio are implemented in the column installations. The results indicate that the project is a success.

Key words: Adverse Geologic Conditions, CFG Columns, Column Filling Ratio, Analysis, Mitigation Measures