Effect Of Temperature On Performance Of Clay Liner In Landfill

The compacted clay liner(CCL) and geosynthetic clay linger(GCL) laid on the bottom and sides of the landfill,which is used for isolating the garbage so as not to pollute the soil and groundwater around. Because the waste generates heat, landfill bottom temperature can be as high as 65℃,which may have negative effects on the permeability and mechanical properties of the clay liners and may threaten the safety of landfill. In this thesis, the landfill common clay liner material is used as the object to investigate the effects of temperature, leachate, confining pressure and other factors on the properties of the liner by laboratory experiment, theoretical analysis and other methodsto study the permeability and mechanical properties under different temperature. The research analyses chemical transport under thermal gradient based on calculation of thermal diffusion andlay the foundation of improving landfill Stability and effectiveness. The main content is as follows:(1) Temperature effect on compacted clay permeability. Simulated leachate and tap water are used as tap water, using modified GDS instrument, to study the permeability of compacted clay under differentradial pressure and temperature to get the relationship between the hydraulic conductivity, temperature and radial pressure, and contrast the result with conventional penetration test.(2) Temperature effect on GCL permeability. Using modified GDS instrument, to study the permeability of GCL under differentradial pressure and temperature to preliminarily discuss the change mechanism of hydraulic conductivity under differentradial pressure and temperature.(3) Temperature effect on compacted clay mechanical properties. Using direct shear test to study the relationship between compacted claymechanical properties and temperature under the action of tap water and simulated leachate(4) Chemical transport calculation considering effect of thermal diffusion. Consider the thermal diffusion transportcaused by thermal gradient on the basis of the traditionalconvection-dispersionequation, to get theanalytic solutions under semi-infinite porous media and analysis chemical transport under thermal diffusion.