Abstract: The soft soil underneath the stockyard of a steel mill is improved by the sand and gravel columns with staged surcharging method. The settlements underneath strips A and B are analyzed by both improved Takagi Shunsuke method and onedimensional Terzaghi consolidation theory. The predicted final settlement values are compared with the monitoring values.

Key words: Sand-gravel columns, Staged loading, Terzaghi Onedimensional consolidation theory of Terzaghi, settlement magnitude, Degree of consolidation