Comparative Analysis of the Soil Geotechnical Characteristics of the Failed and Unfailed Sections of the Onitsha-Enugu Expressway, Southeastern Nigeria.

Abstract

This work compared the soil geotechnical characteristics of the failed sections of the road and that of the un-failed sections of the road to establish whether they are significantly different or related. To achieve this, soil samples from both failed and un-failed sections of the road were analyzed. The data so generated, were tested using Correlation Coefficient for relationship and Students T-test for difference. It was found that there exist insignificant relationship between the failed and the un-failed sections of the road, there is significant difference between the two variables and there is wide discrepancies between the geotechnical characteristics of the failed sections and the standard of soil geotechnical characteristics set by the Federal Ministry of Works for highway sub-grades.  It was therefore concluded that the road failure was due to poor geotechnical characteristics of the soil. The work recommended that the variation in the geotechnical characteristics of the soils along the roadway should be accommodated during reconstruction. Sequel to this, knowledge of soil geotechnical characteristics and underlying geology of an area becomes indispensable before any construction, reconstruction or rehabilitation project commences.