A case history of the construction of a reinforced high embankment on an extra soft ground

This paper describes a case history of the construction of a geotextile-reinforced high embankment on peat. The estimated safety height of the embankment was 1.8 m against to 6 m in design height. Settlement as large as about 1.7 m was also predicted from the results of the laboratory consolidation tests. The use of ground improvement techniques, however, was not accepted in this construction work because of the existence of a well of cold mineral spring quite nearby the site. Under these conditions, to increase the factor of safety of the design embankment to 1.15 immediately after the construction, the use of five layers of a strong geotextile and a stage construction sequence were adopted. The embankment filling was successfully completed without making any serious errors. From the result of this field case history, it was demonstrated that the construction of a high embankment on peat was possible by reinforcing the embankment bottom rigidly, even if ground improvement techniques were not conducted.