ABSTRACT
Several different approaches to the estimation of residual strength have been proposed. The earliest geotechnical approach was based on laboratory experiments. Later, geotechnical approaches based on insitu testing coupled with the backcalculation of apparent shear strengths from actual flow failures have been developed. However, very high uncertainties are associated with the residual strengths estimated using each of these approaches. The residual strength of particulate materials is important in other fields outside of mainstream geotechnical engineering. Evaluation of debris flow behavior has led to fundamental research on the flow behavior of particulates. The rheology of concentrated suspensions of particles in liquids is also important in industrial processes such as the hydraulic transport of materials such as coal, powders, minerals, and animal feeds. Experimental and analytical research in those fields have produced results that could be of use in evaluating residual strength of liquefied soil. A review of past experimental approaches to the measurement of residual strength, including approaches developed outside the field of geotechnical engineering, is presented. The strengths and weaknesses of each experimental approach are discussed. The desirable characteristics of an experimental apparatus that would combine the strengths, and minimize the weaknesses, of existing devices are described. Finally, fabrication of such an apparatus is described.
