A SIMPLIFIED METHOD OF ESTIMATING CONSTRUCTION PORE PRESSURES IN EARTH DAMS

Abstract

A simplified method of evaluating pore pressure behaviors of earth dams during construction was proposed in the present paper. The basic scheme of the method is similar to that presented by Eisenstein et al. (1976), but some simplifications were introduced in the part of consolidation analysis. The main advantages of the method are to estimate generated pore pressures from the results of conventional oedometer tests and to evaluate pore pressure dissipation by using the relationship between the degree of consolidation U and the time factor T in one-dimensional consolidation. Concerning the latter, it is recommended here that U-T relationships be composed from pore pressure measurements in the field, because it is not necessarily sufficient to represent such field consolidation conditions as anisotropic permeability and the difference in drainage systems through laboratory tests. In the comparisons between computed and observed results for three representative earth dams, it was noticed that the present analytical approach on the whole showed good correspondence with pore pressure behaviors in actual dams, offering sufficient accuracy for practical purposes.