THE INFLUENCE OF PARENT ROCK FACTOR AND MECHANICAL STABILIZATION ON THE GEOTECHNICAL PROPERTIES OF SOME RESIDUAL LATERITIC SOILS FROM PARTS OF IBADAN, SOUTHWESTERN NIGERIA OGUNNAIKE, OLUGBENGA KEHINDE MATRIC NUMBER- 116740 UNIVERSITY OF IBADAN B. Sc Thesis, final year project research work, April 2007
Residual soils such as laterites and saprolites forms good shallow founding strata of high strength and low compressibility. Hence they have been considered as excellent materials for the building of roads and embankments (Gidigasu, 1988) as well as for supporting the foundations of buildings, bridges and other structures via piles or raft foundations (Martins and Martins, 1989).
However, the engineering behaviours of these residual soils are not easily predictable due to the fact that the weathering products that results under certain tropical conditions may contain minerals with unusual properties . Also, the in-situ weathering of the parent rock often implies the presence of a relict structure which may persist as a form of weak bonding even in the most extremely weathered products (Fookes, 1993).
Therefore, a deliberate consideration of the inherent parent rock characteristics in residual soils has become a necessity prior to an adequate understanding of the engineering properties and behaviour of special and vital engineering tropical soils.
Examination of the influences of some parent rock factors on the index and strength properties of the studied soils
Examination of the influence of different levels of compaction on the shear strength characteristics of the studied soils
Examination of the variations in the index and shear strength characteristics of the studied soils with the depths of sampling in the soil profile
METHODOLOGY OF RESEARCH
Geological field mapping
to delineate the different geologic zones/units that characterize the geology of the study area
to select site for the collection of soil samples
Petrographic analysis of rock samples by thin-sectioning and photomicrography
to be able to ascertain the nature of the parent rocks
to examine the mineralogy of the parent rocks
to examine the micro-structures of the parent rocks
Sampling of residual soil samples from three different locations underlain by different parent rocks