A THESIS SUBMITTED TO THE FACULTY OF CIVIL ENGINEERING, INSTITUTE OF TECHNOLOGY, SCHOOL OF GRADUATE STUDIES, ARBA MINCH UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN GEOTECHNICAL ENGINEERING

Abstract

Investigation and correlation of engineering properties of soil plays a vital role for examining the suitability of the soils for proposed project work. This paper presents the field and laboratory test results of soils that were performed to investigation and correlation of the engineering properties of soils found in Selamber town. Prediction of compression index & recompression index from the laboratory test was time consuming and laborious. The compression index of clay was determined using oedometer test. In this research, oedometer test was conducted on remoulded clay collected from various places in Selamber town. Laboratory tests namely liquid limit test, plastic limit test, oedometer test have been conducted to arrive the correlations. In this study, an attempt was made to correlate compression index (Cc) with liquid limit and plasticity index using MS EXCEL s trend line concept. The compression index was predicted also with the help of regression analysis. In order to classify soil, field and laboratory tests were accompanied on selected 8 pits or soil samples which are taken from the town section randomly. The test results showed that the field dry density ranges from 1.79g/cc to 1.95g/cc, LL ranges from 56.35% to 93.5%, PL ranges from 31.59% to 47.22%, PI ranges from 18.25% to 52.50%, OMC ranges from 24.24 to 34.15%, MDD ranges from 1.28g/cc to 1.66g/cc, UC ranges from 102.48 to 166.76 Kpa and Cc ranges from 0.01 to 0.07. According to USCS and AASHTO the soil around the study area are grouped under MH & A-7 5. Cc & Cr tests were performed on eight soil samples in the laboratory, collected from various locations in Selamber town. Investigation of the experimental data indicated that there exist a good correlation among the actual value and predicted value of Cc & Cr. Best important equations are proposed, applicable with sufficient accuracy for preliminary identification of material for the local area. The models for Cr & Cc is the function of (LL), (NMC), (Bd), (PL), (p200), i.e. Cr & Cc =fn(LL, PL, PI, NMC, P200, Bd, OMC, MDD) i.e. Cr & Cc =fn(LL, PL, w, Bd) with recommended equations for 3m  