Municipal Waste Accumulations as Geotechmcal Materials -The Case of Dona Juana Sanitary Landfill, Bogota-Colombia

摘要

In municipal waste materials, as in soils, strength and stiffness originate in the solid phase and depend on the effective stress developed within. However, as time passes, mechanical properties decrease due to the reduction of the solid phase, the organic part (which is predominant in municipal wastes) being trasformed into liquid and gas. Therefore the geomechanical properties of municipal wastes and their evolution in time, depend mainly on their initial composition, which in turn dictate the biochemical rate of transformation of organic constituents into leachate and biogas, which generate pore pressures that further reduce effective stresses. Human wastes constitutes an ever growing by-product of Man and their accumulation in sanitary landfills, initially viewed only as an environmental issue has become an interesting and developing geotechnical field, mainly due to some catastrophic failures as the one that unexpectedly ocurred in Dona Juana landfill in September 1997.