Liquid Depth Study And Stability Analysis Of Municipal Solid Waste Landfill

With the improvement in the urbanization level, the generation of municipal solid waste (MSW) increases rapidly in China.Due to lack of knowledge of the strength of MSW, landfill failure took place worldwide, leading to casualty and property losses and enormous environmental disaster. Leachate level is essential for the stability of landfill slope, with the landfill leachate water level increased, pore water pressure also become greater which causes the shear strength of landfill reduce and lead to slope failure. Therefore, both from economic necessity or environmental protection the research of landfill leachate level and stability is necessary.The paper firstly based on research work of domestic and international, propose three forms of the existence leachate water level:preched leachate, main leachate mound,bottom leachate mound. For the preched leachate, this paper based on the study of saturated unsaturated seepage theory, investigate the formation and growth of preched leachate, and the results shows that a certain amount of preched leachate will be formed when rainfall intensity is heavy and waste saturated hydraulic conductivity is small. Initial moisture content mainly affects occur time, and has little effect of final state. For bottom leachate mound and main leachate mound, based on the extended Dupuit assumption, a computational solution is presented to calculate the transient liquid head. Comparing with the results calculated by Ke Han (2005), the present method is shown to be more rational and accurate. By means of parameter analysis, it is found that when the permeability coefficient and slope decrease, the distance the drainage increase the stable time will be longer and the leachate water level will increase.Based on Engineering problems and limit equilibrium stability analysis this paper provide a computer software for predicting slope stability.The overall structure and main features of the computer software were presented.Then introduced the software application and engineering examples, the results show that the software has good ease of use for terrain modeling, operation with complex conditions.Based on study of leachate level, study the influence of leachate lever on landfill slope stability.The higher the water level and overflow, the smaller safety factor, and more prone to shallow slide.Analysis the effect of preched leachate on the safety factor, and compare the same water lever of preched leachate and main leachate mound.Combine with Mechanical properties of waste, propose the mechanical parameters of waste with age,study the slope stability safety of whole process of waste landfill.