effects of landfill leachate on mechanical behaviour of adjacent soil: a case study of saravan landfill, rasht, iran

Urban waste in most cities of iran is dumped without proper standards of landfill construction. improper implementation of waste barriers leaks off leachate into the surrounding areas, causing soil contamination and other serious environmental problems. the main goal of this study is to determine the possible effects of leachate on the geotechnical properties of contaminated soils around the dump site and estimating a safe zone for a landfill site. in this regard, uniaxial compression, direct shear, consolidation and permeability tests were carried out on several samples to assess the possible effects. sem tests were also conducted to precisely assess the geotechnical parameters and clarify the possible changes in soil characteristics. results showed that by increasing leachate concentration, maximum uniaxial and shear stresses decrease, and the volumetric strain increases. this behavior continues by getting closer to the contamination source. a decreasing trend in the cohesion and coefficient of permeability and a relatively low decreasing trend in the internal friction angle $$(varphi )$$ were also observed as the contamination concentration increased. according to the results, a 600 m distance from the contamination source is proposed as a safe zone, in which the soil holds its initial properties. this study provides additional insight into the effects of leachate on the spoil texture of soil.