FINITE DEFORMATION ELASTO-PLASTIC FE ANALYSIS ON THE PEAT GROUND UNDER VACUUM SURCHARGE PRELOADING

Abstract

Comparing with clay, as the compressibility of peat is extremely high and consolidation coefficient c_v is strongly dependent on consolidation stress, it is difficult in many cases to apply Terzaghi consolidation theory which is based on the assumption of constant c_v and without taking into account of the change of initial thickness of consolidation layer. In this paper, the possibility of accurate prediction of the horizontal deformation as well as the vertical settlement of a deep peaty soft ground loaded by test embankment with vacuum preconsolidation is investigated by using soil-water coupled elasto-plastic finite element (FE) analysis which takes into account of consolidation stress dependency of c_v and effects of geometrical changes of deforming soil body. A series of simulation analysis was also performed by changing the combination of the magnitude of negative pressure and filling rate to investigate the possibility of establishing the optimum design procedure for this particular ground improving method.