New Approach to Analysis of Consolidation Data at Early Times

Abstract

AbstractIf U¯v>0.50, Asaoka’s method can be used to evaluate cv(s) and scf from settlement data, but the method leads to unsafe results when the data are measured when U¯v<0.50 (i.e., cv much too high and scf much too low). For field conditions where all data have (U¯v)<0.50, one cannot predict scf or estimate cv(s) solely on the basis of measurements of surface settlement. These conditions require analysis of both piezometer and settlement data together with knowledge of the initial excess pore pressure (u0). With proper instrumentation, Johnson’s incremental time (Δt) graphical method can be used to estimate cv and scf, but this technique tends to be cumbersome and imprecise. Two new techniques (EFM-1 and EFM-2) based on the Laplace Transform are proposed. The accuracy of cv and scf estimates using EFM-1 and EFM-2 are evaluated as functions of piezometer location, time, and uncertainty in u/u0.