IDENTIFICATION OF COLLAPSIBILITY POTENTIAL OF SOILS ALONG SHASHEMENE – AJE ROAD CORRIDOR: AMBURE SITE

Abstract

Large areas of the earth’s surface are covered by soils that are susceptible to large reduction in bulk volume when they are near to saturation (Knodel, 1992). These soils are termed as collapsing soils and are common in many parts of Ethiopia. This study is concerned with the identification of the collapsibility potential of soil found along Shashemene – Aje road corridor, in particular at Ambure site, Western Arsi zone, Ethiopia. The study was carried out as relatively little is known about the collapse phenomenon in the silty/ fine sands. The aim of the study was achieved through the experimental work which included engineering tests like: one dimensional oedometer testing and direct shear strength testing; and classification tests like: moisture content, bulk dry density, compaction, particle size analysis, and specific gravity tests. To provide a better understanding of the collapse behavior of the soil, classification tests were performed to make indicator analyses and evaluation of collapsibility potential using various empirical correlations. Based on the obtained results, soils from the area of study have a collapse potential values ranges from 3.81% to 5.89% and found moderate to highly collapsible types of soils in nature. From the findings of this study, as the Ethiopian Roads Authority site investigation manual does not consider the significant effects of these types of soils, the author suggests a direction in providing the design and construction specifications of problematic soils of collapsible types.