Applications of some ground improvement techniques in various sands

This thesis presents an extensive experimental investigation on the use of some ground improvement applications in various sands. In recent years, investigations in biotreatment, fly ash, and waste tire use have enabled significant advances in understanding the effect of microorganisms and waste materials in the development of soil behaviour. Increase in the amount of waste materials (i.e., fly ash and waste tires) results in an environmental problem in Turkey, as well as in many regions of the world. Fly ash and waste tire applications in Turkey are not widely employed, although it is effectively used in some countries, and thereby decreases the possible effect on the environment. Some applications, in which waste tires and fly ash are used, are lightweight fill material in embankments, insulation layer, and drainage applications. The compressive strength and bearing capacity of biotreated specimens were compared to those of the untreated specimens. Behaviour of a sand with fly ash- lime mixtures were systematically characterized in proctor, permeability, oedometer, and CBR testing apparatuses. A series of laboratory investigation of a sand and processed waste tires (i.e., tire crumb, tire buffing) mixtures at various contents was performed oedometer, permeability and direct shear tests. Additionally, Scanning Electron Microscope (SEM) pictures were taken to examine the microstructure of the specimens. From the experimental results, it was observed that the mechanical properties of the soils tested have been affected by biotreatment, fly ash, and waste tire inclusion.