Consolidation Coefficient in Horizontal Direction (Ch) Determined from Field Settlement Data By Using Terzaghi, Asaoka, and Finite Element Methods

Abstract

In order to predict the consolidation period in the field, consolidation coefficient in vertical direction (C_v) parameter is needed. When vertical drains installed in the compressible layer in order to shortened the consolidation period, it needs consolidation coefficient in horizontal direction (C_h). This C_h parameter has to be determined from the field settlement that usually obtained from the trial embankment.  However, it is very expensive to carry out the trial embankment; therefore, it is usually assumed to be 2 till 5xC_v. In this paper, the assumption of the C_h value will be proven by using field settlement data taken from the trial embankment at the reclamation area for container yard at Kuala Tanjung, Medan, By choosing the C_h value, the compression vs time curves were predicted by adopting the Terzaghi, Asaoka, and Finite Element methods. Afterwards, these predicted settlement curves were plotted with the field settlement curves; from this plotting, it could be figured out the predicted curves which has C_h value the same with the field C_h value. The results show that from three methods adopted in this study, only the Terzaghi and the Asaoka methods give satisfactory results in settlement prediction. Consequently, only the Terzaghi and Asaoka methods are adopted to determine the C_h value. The C_h value obtained is about the same, that is 3C_v until 5C_v. When that C_h value used back to predict the settlement, the Asaoka method gives better result than the Terzaghi method.