the geosynthetics have been widely applied to reinforcing their soft grounds; but the calculation methods still have some shortcomings. The paper made a study from the aspect of limit analysis theory; the slip line method was adopted to improve the upper-bound theorem of limit analysis and deduced a new limit analysis method of ground. When the destructive width of embankment was regarded as a variable
this paper solved the ultimate height of the embankment based on the deduced formulas. The calculated results of the ultimate height agreed well with the measured ones
as the comparison and analysis of project cases showed. The results provide a new efficient way for the design of soft ground embankments.