A COMPUTATIONAL TECHNIQUE FOR ASSESSING THE COMPRESSION PATHS OF RESIDUAL SOILS

Of the civil engineering construction materials, soil is distinctive being a geologic material, most often engineered, as it exists, unlike other processed or manufactured materials like concrete or steel. Therefore, it becomes essential to characterize the soil appropriately based on factual data available at discrete locations. The discrete locations are the places where samples are extracted and in-situ tests are performed, these locations are chosen based on possible variations in soil conditions in the proposed area of construction of a civil engineering structure. Soil conditions between such discrete locations can be deduced by scientific principles. An attempt has been made in the present investigation to propose a computational technique based on phenomenological observation made on experimental findings on ten different soils extracted from different depths form a residual soil deposit in Tirupati region. The soil samples show inherent variation in basic characteristics in terms of grain size and plasticity characteristics. The soils are predominantly Clayey with silt, sand in significant proportions. These soils are typical of kind encountered in practice. The compression paths of natural soils are determined and the these paths are shown vis-àvis the compression paths of remolded soils compressed from their equivalent liquid limit states , free from stress , time and environmental effects in order to ascertain the relative positioning so as to understand the states of compression paths of natural soils . The analysis of test results indicate that the compression paths vary from the compression paths of natural soils and the paths follow a consistent mathematical pattern when normalized with respective initial void ratios with stress. These observations form basis to propose a simple computational technique to predict the compressibility behaviour of natural residual soils. The mathematical form observed is applied to the data published in literature to bring out the applicability of the phenomenological model.