GEOTECHNICAL PROPERTIES OF SOIL BENEATH SOLID WASTE DUMPSITE

CASE STUDY OF PLATEAU STATE, NIGERIA

Abstract

Indiscriminate dumping of high volume of municipal solid waste within buildup area close to the people in Jos as result of improvement in the living standard, care free altitude, were the geology aid percolation of leachate affect the geotechnical properties of soil in the area. Soil gets contaminated and the properties of soil like specific gravity, maximum dry density, atterberg Limits permeability and shear strength changes extensively. Geotechnical procedures were experimentally adopted. Results shows that the percentage of particle size distribution at 94.77 (GeroNyango) and 91.23 (Sabon GariAtu Akan village) are more prone to liquid percolation due to the nature of soil, while 66.0 (Kwang-Ray field) and 66.0 (Tina Junction) indicate less liquid percolation. Results from this study demonstrates that  highest concentrations of Atterberg limits (liquid limit, plastic limit and plasticity index) 79,28 &51 while the lowest concentration of Atterberg limits is in 58,26 &32, amount of fines increased, the resultant specific surfaces and activity of the material also increased. The result of water content, specific gravity, compaction and strength parameters show that ST3, ST5 and control site (ST7) exhibiting higher values than ST1, ST2 and ST4, indicating that ST3, ST5, ST6 and ST7 sites are not good to use for open dumping because of high rate of liquid percolation.  The moisture content of disposal sites varied from 20.20(ST1) to 40.20(ST3) with control site soil 32.10 on the surface while moisture content of disposal sites at subsurface range from 15.30(ST1) to 37.60(ST6) with normal soil of 30.76(ST7). Optimum disposal surface ranges from 17.30(ST4) to 19.35(ST3), less than the normal soil 1.60(ST7) while the optimum subsurface range from 17.72(ST6) to 20.50(ST3) with normal soil 1.97 (ST7).Soil beneath municipal  solid waste can be contaminated with constituents of leachate especially at ST3 and ST6 because all measured parameters have potential for leachate percolation.