A Study on Effect of Sample Disturbance in Estimating Settlement of Foundations

Geotechnical properties of soil estimated from laboratory tests are generally affected by sample disturbance. It is difficult to deal with sample disturbance during the laboratory testing of soft soil. Estimation of preconsolidation stress from laboratory tests is highly affected by sample disturbance. The concept of preconsolidation stress is useful in analyzing and predicting settlement behavior of soft soils. Hence, accurate determination of preconsolidation stress is important for settlement analysis. Estimation of preconsolidation stress depends on graphical methods. Many graphical approaches are available in the literature for estimation of preconsolidation stress from the laboratory consolidation tests. In this study, the consolidation test data is taken from (Egypt, California, Vietnam and India) different locations around the world. The effect of sample disturbance on the compression curve for estimation of preconsolidation stress and settlement of soft soils is presented. The approaches used for determining the preconsolidation stress from the consolidation tests are based on graphical interpretation procedures of void ratio (e) versus effective stress \(\left( {\sigma^{\prime}} \right)\) data. The methods used in this study are semi-logarithmic (Casagrand, 1936 and (Schmertmann in The undisturbed consolidation behavior of clay. Transactions of the American Society of Civil Engineers, pp 1201–1233)). The true in situ settlements from the true in situ compression curves are estimated and compared with the settlements obtained from the laboratory curves. .