Development and selected applications of a low hydraulic head laboratory permeameter : MCINNES, DB, PUBLIC WKS DEPT. W. A. AUS 4F, 1T, 13R. 2ND AUS-N. Z. CONF. GEOMECH, BRISBANE, 1975, INST. ENGRS, AUS. NAT. CONF. PUBL. NO. 75/4, P228–232

Abstract

Liquid flow through soil developed under low hydraulic head conditions is discussed. Such conditions arise for example in studies of seepage from shallow ground evaporation tanks, and infiltration phenomena. A laboratory technique for the determination of soil permeability under these conditions and closely simulating those evident insitu is described. Features of the technique include means for accurately maintaining and measuring the vertically downwards flow from a shallow pool of water ponded on one of the flat ends of a cylindrical specimen. Special attention has been given to the problem of specimen boundary leakage often encountered in laboratory permeability testing of gravels. A bentonite gel jacket is used to surround the specimen and eliminate leakage. The use of the technique also allows for the direct testing, without re-compaction, of field tube samples and for a study of the effect of drying subsequent to compaction upon permeability. Certain applications of the use of the technique and associated results are discussed. These applications include a determination of: (a) The influence of compaction upon the water conductivity characteristics of road shoulder materials after long periods of wetting. (b) The influence of desiccation, following compaction and prior to wetting, upon the permeability of a clayey-sand. Comments are then made relating to the practical implications of these permeability measurements.