Calculation of leachate drainage volume of landfills based on seepage-compression coupling action

At present the hydrological analysis method or empirical formula is usually used in leachate drainage volume analysis. The leachate drainage volume is underestimated since the leachate generation induced by the compression of MSW is not taken into account in these methods. Also, the leachate generation after field sealing cannot be obtained or it may be underestimated. By means of FEM, the compression of MSW and the seepage of leachate in landfill are simulated, and a numerical analysis method is proposed to calculate the leachate drainage volume for each filling stage with time. The variation of saturated hydraulic conductivity of MSW with compression is taken into consideration in the analysis procedure. The influences of the initial moisture content, compressibility and precipitation on the leachate drainage volume are studied and verified by use of the field measured data. The results show that the initial moisture content of waste, compressibility and precipitation are the main factors to determine the leachate drainage volume. The leachate drainage volume of MSW whose initial compression index is 1.31 is increased by 26.0% than that of MSW whose compression index is 0 in the landfill period. The leachate generation is smaller and has an easy curve when the zoning landfilling is taken.