Studies on evaluation of parameters of material model for sand and sand silt mixtures

Abstract

Advanced computer technology and availability of advanced constitutive models, has enhanced the knowledge in geotechnical engineering field manifold. To account for a wide range of geotechnical applications and to idealize the complex behavior and response of soil structure systems, a number of constitutive, deformation and boundary models have been developed. The geotechnical engineer must use the appropriate model to predict the performance of soil structure system. The choice of a certain model depends on the specific application for which the model is believed to provide a best possible prediction. Usage of proper soil parameter is the key ingredient in computing soil responses by assuming a suitable model. The selected model should represent the soil response in a reasonable way. Soil parameters are usually identified by laboratory investigations performed on the samples or from in-situ tests. Practicing engineers should also make use of constitutive model which provides a reasonable fit to data from a range of laboratory tests. Natural deposits of sands have different gradation characteristics and with the advent of modern technology, construction on alluvium and loose deposits has become possible. Sand is one of the important geomaterials encountered in Engineering problems, composition and gradation characteristics of which depends on its geological process of formation. Needless to say, one may find different sands and/or most of the times along with fines, varying over very small intervals of even a few millimeters. The conventional methods of analysis, involving sandy soils, fail to address the presence of fines. The presence of small amount fines alters the behavior of sand which needs to be considered for safe design of structures. The main aim of this research work is to highlight the importance of influence of gradation characteristics and presence of non-plastic fines in the constitutive behavior of loose sands. newline