Prediction of Swelling Pressure from Index Properties of Expansive Soils found in Burayu Town

Abstract

Expansive soils are recognized as problematic soils that impose several challenges for civil engineers. Such soils undergo significant volume change in case water penetrates into them, and they shrink as they lose moisture. Lightly-loaded engineering structures such as pavements, single story buildings, railways and walkways may experience severe damages when they are founded on such soils. A considerable surface area of Burayu town covered by expansive soils, which have a tendency to undergo volume change due to change in water content variation. Reconnaissance study of the area carried by visiting the entire part and the surrounding part of the town. For this study thirty-(30) samples collected from 10(ten) test pits for different laboratory tests and each samples are determined according to American Society of Testing Materials (ASTM) and their result and discussions was stated. This Research study is aimed to predict the swelling pressure from index properties of expansive soils found in Burayu town including classification of soil using AASHTO (American Association of State Highway and transportation officials) and Unified soil classification systems (USCS) to know the expansiveness of the soils the study area. The study also carried out on examining the nature and mechanism of swell-shrink behavior of expansive soils. The statistical analysis conducted using Computer program Software (SPSS 20) and Microsoft-Excel to develop Empirical between soil index properties and swelling pressure of expansive soil of the study area. The outcome of this study is Modelling of swelling pressure from index properties of expansive soils in the study area. Based on both single and multiple linear regression analysis relatively good correlation is obtained by combining Swelling pressure (Sp) with soil index properties. From the analysis the equations developed are SP = 4.134*PI - 2.406*NMC - 95.564*γd - 247.366*Ac + 381.831 with coefficient of determination (R2) of 0.869 for multiple linear regression and Sp = 387.51 - 158.1*γd with coefficient of determination R2 of 0.829 for single linear regression. The Results on the validity of the newly developed correlation with control test results shows that, the correlation of swelling pressure value with soil index properties is valid only for preliminary design purposes and estimation of swelling pressure of the soils the study area.