Performance of filter drains under large embankment loads

Abstract

A testing apparatus was developed for the determination of the change in permeability of coarse porous media subjected to a decrease in porosity . literature survey was conducted to establish the design criteria for the flow and loading tests. The mthemaUcal model describing flow through course porous media was further developed on a theoretical basis by postulating the layered medium model. Ihis model is a means by which the variability of the particle sizes in the medium is taken into account. The design, construction and operation of the testing apparatus is des:rvx-d. The specimen tested was laded up uo 3,45 MPa; consequently ' the Fbrcheimer aquation in the form of K , Ci/R + Cg was found to yield repeatable values for tiic turbulent friction factor C2, thus providing a means of predicting the change in permeability if the change in porosity and effective particle diameter are known.