Implications of the Engineering Geological Properties of Soils in the Implementation of the Greater Jos Master Plan, North Central Nigeria

Abstract

A study of the engineering properties of the subsurface soil in the Greater Jos Master Plan development area has been carried out to address the paucity of engineering data in the area. The study became necessary because the rapid urbanization has led to limited construction land with more ground prone to instability due to reworking by mining and related activities. The study area is located within Latitudes 09º 48' 20'' to 09º 53'20''N and Longitudes 08º 53' 54'' to 08º 57 '00'' E and extending over 54km2 on Naraguta Sheet 168NE. Surface geological mapping was carried out to confirm the existing geology. Geotechnical properties of soils were determined by analysis of soil samples for 38 locations. While 94 static water level measurements provided additional information on groundwater conditions. The area is underlain by the Jos-Bukuru Complex rocks predominantly biotite granites differentiated on the basis of mode of formation, mineralogy and texture. Soils derived from weathering of the rocks revealed gradual decomposition from gravel, sand, and silt-sized particles to lateritic clays. The soils are considered to have low to medium plasticity/compressibility, expansiveness, and swelling potential across all rock types. The static water table depicts fluctuation in the water table varying between 2.9 and 3.9m. These findings are expected to serve as guide in the choice of design and construction and as a baseline subsurface soil compendium for planning and urban development in the Greater Jos Master plan and for further studies.

Emphasizing the significance of site investigation for infrastructural development of the Greater-Jos Master Plan

“…Also, The Greater-Jos Master Plan admits the requirements for stable foundations for roads, buildings, dams, bridges, masts and other civil structures; and hence suggests soil investigations/soil material testing and reports for design purposes to ascertain the engineering behaviour of the soils. Furthermore, literature review on the engineering properties on the Jos-Plateau reveals that soil investigation from an engineering point of view has been greatly overlooked; although these soils are being used as major source of construction material and for foundation of structures (Wazoh & Mallo, 2021). Except for Government owned projects, study of the behaviour of these soils has been neglected by the general public.…”