Engineering properties of kobo town soil, northernethiopia especially on expansive soil

Abstract

The Raya Kobo town is characterized by kola climate, low rain fall distribution and the area have high amount of ground water found at average depth of 60 meters and discharge 50 l/sec. average seasonal ground water level fluctuation at kobo town is 5 to 23 meters. In the town kobo expansive soil locally called (Walka). This soil damaged many structures such as building, roads, irrigation canals and other civil engineering structures built over the soil. This study is done with the intention of examining the index properties of expansive soils of kobo, swelling pressure and strength properties based on secondary data taken from (AWDSW). This secondary data can indicate problem of soils and provide helpful to estimate of the expected swelling of expansive soils(walka) of kobo town are generally black in color and have high swelling potential. From the secondary data shown free swell and swelling pressure of kobo town expansive soils indicate that the soil can cause significant damage to light structures unless proper design and construction measures are taken those expansive soils have very high shear strength in the dry season and low in the wet season. Therefore expansive soils of kobo town soil can cause severe damage to civil engineering structures built in the area; otherwise proper counter measures are taken.