Beschreibung:
Soil-bentonite cut-off walls are widely used in landfill projects. In recent years, attapulgite has been suggested as a substitute for bentonite in cut-off wall applications by scholars due to its distinct advantages over bentonite. However, the biochemical degradation of waste in landfills generates a large amount of heat, and the temperature can reach 60 °C. There is a lack of corresponding studies on the effect of temperature on the permeability of soil-attapulgite cut-off walls in municipal solid waste landfill. To this end, this paper carries out experimental research on sand-attapulgite consolidation tests, infiltration tests and liquid limit tests at different temperatures. The results show that the hydraulic conductivity of sand-attapulgite samples gradually increases with increasing temperature, and the response of the hydraulic conductivity of sand-attapulgite samples to temperature was further analysed for different doses of attapulgite and consolidation pressures. It was found that the response of the hydraulic conductivity kf to temperature T of the sand-attapulgite samples increased with increasing attapulgite dosage, while the response of the hydraulic conductivity kf to temperature T of the sand-attapulgite samples decreased with increasing consolidation pressure. Finally, according to the calculation method proposed by Zhang et al. (2019), the consolidation theoretical hydraulic conductivity of soil was calculated. The Kozeny‒Carman equation was further modified using the void ratio and liquid limit to obtain a prediction equation for the hydraulic conductivity of sand-attapulgite at different temperatures. This study can provide an important theoretical basis and data support for the development of new high-performance long-life vertical cut-off walls in a municipal solid waste landfill