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.
