Effect of cycles of drying and saturation on sub-base soils of MSW landfill (case study: Tehran Kahrizak region)

Waste control and its adequate disposal are included as a substantial problem in humanlife in this world. So far vast studies have been carried out at in this regards, and several ofself healing methods have been common in practice. Since recovery of waste is not costeffective and is with the technologic limitations, with respect to the mentioned reasons, the waste Land fill is a general solution. However, practically it is impossible to give or achieve a general solution. An adequate Land fill is a place for waste Land fill which must be a location that don’t infect the environment in short term or long term. The most important problem is use of a method that doesnt let to waste emulsion to leak into the ground or to control it properly. In this research for decrease of leakage of emulsion waste, two basic specifications that are less cracking and more self healing for determination of the efficiency of soils application was analyzed. In this reason chemical, mechanical and permeability test based on ASTM standard was perform on the Kahrizak Landfill soil samples, and finally with respect to the obtained results from various cycles of drying and saturation, the permeability coefficient was calculated. Permeability coefficients in the end of 1st & 2nd cycles of drying and saturation divided by initial permeability coefficient and also the relative permeability was included as the criteria of soil efficiency for application in impermeable layers. And whatever the relative permeability of soil close to the 1, then this type of soil is ideal for using in this field also it was found that soils with less plasticity index have lesser cracks during drying.