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A method is presented for evaluating the effect of strain rate on pressuremeter tests. It can analyse the combined effects of higher strain rate and variation of strain rate across the soil mass on the undrained strength derived from pressuremeter tests. The results of a parametric study using this method indicate that the stress-strain curves derived from the pressuremeter curves differ from the true material stress-strain curves and that the undrained strength is overestimated. These differ- ences are quantified. L'article présente une méthode pour évaluer I'effet du taux de déformation sur les essais pressiométriques. En utilisant la mkthode il est possible d'analyser les effects combinés d'un taux de déformation plus élévé et d'une variation dans le taux de déformation à travers la masse du sol sur la résistance non-drainée obtenue à partir d'essais pressiométriques. Les résultats d'une étude paramétrique utilisant cette méthode indiquent que les courbes de contrainte/déformation obtenues à partir des courbes pressiométriques différent des véritables courbes de contrainte/déformation et quela résistance non-drainée est surestimée. Ces différences sont quantifiées.

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This is the last Interim Report on this research.Its content is well summarized by the title of the Report. The prediction techniques created in the research are much more rapid than time consuming physical measurements often now utilized.The effect of soil mineralogy on permeability was also investigated and some conclusions reached.The Final Report on this Study is also in preparation and will correlate and summarize the many findings of the several interim reports toward achievement of the objectives of the research.This report is submitted as partial fulfillment of these objectives. Natural soils and artificial mixtures of silt and kaolin were used. The natural soils were provided by researchers at the University of Illinois; they also provided the associated soil-moisture characteristic curves (as physically measured). Pore size distributions were obtained by mercury-intrusion procedures on f reeze-dried specimens .The soil-moisture characteristic curve can be used to predict soil equilibrium water content. This curve relates water content and soil suction.Instead of using the time consuming physical measurement procedures, this study created techniques to predict the curve from pore size distribution data in much less time.The effect of soil mineralogy on permeability is examined by comparing soil permeability to air and to water. Pore size distribution models can predict air permeability or water permeability but not both; this is the mineralogy effect.A correlation was effected between activity and the air to water permeability ratio; this factor is used to correct for the effect and, thus, account for it.Mineralogy (Low, 1961(Low, , 1979