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Geotechnical membrane is often used in dam engineering to prevent the seepage. But the research of the influence of impervious membrane on the seepage of a dam is not enough. Combining the indoor model experiment and numerical analysis methods, the influence of the impermeable membrane’s blanket length on the seepage of a dam had been carried out in present paper. By analyzing the results from these two methods, it was found that the seepage quantity of the dam linearly changed with the increase of the blanket length. Besides, bases on the numerical analysis method, the influence of different horizontal impervious blanket length on the seepage of a dam had been investigated, and the calculation formula for different thickness of the foundation had been fitted. Finally, the optimum length of horizontal blanket for different dam foundation was analyzed.

In this study, the permeability of fresh municipal solid waste (MSW) was investigated to understand the relationship between the permeation rate and hydraulic gradients, and the relationship between the permeability coefficient and the initial density. A large-scale permeability test apparatus was used and 15 fresh MSW samples were examined. Three mixture proportions were adopted and five initial densities of 0.7, 0.8, 0.9, 1.0, and 1.1 g/cm3 were selected for each mixture proportion. It was found that the seepage did not occur until the hydraulic gradient reached a critical value and the critical hydraulic gradient increased with the initial density. The permeation rate increased with the hydraulic gradient. A linear relationship was found between permeation rate and hydraulic gradient. It was also found that the permeability coefficient decreased gradually with the initial density of fresh MSW and they followed a linear relationship with the fitted coefficients greater than 0.99. In addition, the prediction model of the permeability coefficient was proposed. Furthermore, the permeability coefficient of fresh MSW was found to have some interrelationship with the sample’s mixture proportions and the organic content. Under the same condition, the permeability coefficient decreased with the organic content. The range of the permeability coefficient obtained for different mixture proportions along with other findings from this study could provide a reference guide for the analysis of the permeability of a landfill.

The direct shear test and the compression test of municipal solid waste are carried out by using a large-scale test equipment to study the shear strength properties of municipal solid waste. The municipal solid waste materials are divided into three parts, and an appropriate proportion is selected for these three parts. The relationships between shear stress, shear strain, compression strain, shear strength and time are studied. Research results show that the shear stress does not vary linearly with the shear strain, and the curve of the shear stress versus shear strain is a strain hardening curve, even the shear strain exceed 20%. The curve of the vertical strain versus logarithmic time can be fitted into a fold line, and the relationship between the initial void ratio and logarithmic time can also be fitted into a fold line. Besides, the curve of the shear stress and the logarithmic shear strain can be fitted into a linear line, and the slope of the line is at the same value 0.97. On the basis of the experiments, a new model has been presented, which is simple and of less parameters.

By using a new developed large scale compression testing instrument, the compressibility for municipal solid waste with higher content of organic matter have been studied. The municipal solid waste is divided into three parts: the material that is easy to be biodegraded, reinforced material that is difficult to be biodegraded and incompressible solid material. The proportions of these three parts are 80%, 5%, and 15%, respectively. Laboratory test has been performed by applying this instrument for these test samples under different pressure. The testing results show that the compression strain is increased by the pressure applying on the testing sample, and the strain is about 85% under the pressure 800kPa, and it is a very high strain for the proportions of municipal solid waste, and the strain is gradual coming to stable with the time expand under the same pressure. The relationship between initial void ratio and the logarithm pressure is linear, and the compression index is 1.63. The relationship between initial void ratio and the pressure is a typical curve as curve of the traditional soil, and the compression coefficient is 3.87.

Based on the investigation of eight waste transfer stations in Hangzhou, China, the component of municipal solid waste has been studied. The municipal solid waste is divided into three part, those are incompressible solid material, reinforced material that is difficult to be biodegraded and the material that is easy to be biodegraded. The proportions of these three parts are 35%, 15% and 50%, respectively. Laboratory test has been performed by using a new developed compression test instrument. The testing results show that the total compression is composed of three parts, those are stress compression, consolidation compression and creep compression. Besides, the consolidation compression could be divided into two parts, one is due to the discharging of water from the void of the municipal solid waste and the other is due to the discharging of water and air which are generated from the degradation of organic substance in municipal solid waste. The stress compression and the consolidation compression are about 80% to 85% of the total compression and the creep compression is about 15% to 20% of the total compression. The compression coefficient is 5.47, and the compression index is 1.27.