A Formulation for Estimating the Compression of Fibrous Peat Using Three Parameters

Abstract

High variability in the results of laboratory tests with peat poses difficulties in the application of the classic consolidation theory to the prediction of settlement in the field. This article presents a formulation involving a three-parameter function that can define a wide range of strain history in peat. This formulation can estimate the maximum possible strain under a specific stress and the entire strain history as a function of time. The parameters necessary for the formulation can be derived from a simple short-term compression test. The formulation is based on the results of strain-history measurement in laboratory one-dimensional, triaxial, and isotropic triaxial consolidation tests of fibrous peat specimens and field measurement of embankment settlement. The formulation is extended to estimate the strain under multiple stress increments based on the measured strain history corresponding to the first stress increment. Based on this formulation, settlement time charts can be developed for an individual peat site, and the strain history and maximum possible strain under different loads can be directly estimated based on the measured initial strain history.