Geopysical and Geotechnical Investigation of Cham Failed Dam Project, Ne Nigeria
Author Affiliations
- 1Department of Geology Federal University of Technology, Yola, NIGERIA
Res. J. Recent Sci., Volume 1, Issue (2), Pages 1-18, February,2 (2012)
Abstract
The geophysical and geotechnical techniques were applied in order to determine the immediate and remote causes of a failed dam project in Cham area NE Nigeria. Details of site investigation for the Cham dam are presented. Geologically, the dam-site rests on the geologically disturbed Yolde Formation. The course of the Cham River is structurally controlled by the underlying strike-slip and dip-slip faults. Ground geological investigation revealed the presence of joints, faults and associated slicken-sides and shear zones as well as desiccation cracks within the rock formations. Geophysical investigations confirms that these joints and fault zone extends more than 35 meters below the river beds. It also revealed the presence of shally clay, lateritic dark clay, fissile shale and friable siltstone to depths of more than 35 meters below the river bed. Laboratory studies of the engineering properties of the rocks disclosed a mean optimum moisture content of 14.6% at a mean maximum dry density of 1.80 mg/m, mean plasticity index value of 34.5% and a mean CBR value of 3% suggesting a highly weathered, plastic, friable and structurally weak rocks. These studies helped in explaining both the immediate and remote causes of the failed dam project.
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