Javad Tabatabaee Yazdi - PhD, Geotech. Eng
N.W.A. Broug Ir. - Civil Eng, Bosboom, the Netherlands

In this paper stability of an embankment dam is considered where placed upon a two consecutive soft and firm clay layer with assessment of development of pore water pressure and consolidation settlement. Due to the result of calculation for primary and secondary settlement, it is understood that embankment may undergo a relatively large settlement in short period in top soft soil while long term consolidation encountered in firm soil may not have so harm structurally if the short and long term stability become satisfied. Verification by stability analysis in conjunction with staged construction is made. It is concluded that construction time should allow for at least 50% consolidation after each 2,5 m load increment. For this purpose, installation of vertical drainage found to be necessary.

Embankment, soft soil, soft clay, consolidation, staged construction