Experimental Study On Influencing Factors To Deformation And Strength For Municipal Solid Waste

With the rapid social and economic development, how to handle the municipal solid waste effectively has already become the focus problem to which the society and people pay close attention nowadays. Land filling is one of the primary methods for municipal solid waste disposal. The key technology of landfill is to ensure the hazards of MSW to be long-time closed in landfill to avoid surrounding environment pollution. Therefore, to design a stable and security landfill, it is important to know the mechanical properties of MSW and propose the method of determination of the mechanical properties of MSW, establish the constitutive model of China MSW. It is convenient to provide an important basis for the design &construction of landfill.The mechanical properties of MSW are key basis for stability analysis of landfill. Previous researchers study the MSW by two main ways, one is laboratory test, and the other is field test. The laboratory test includes direct shear test, compression without lateral, different size Triaxial Compression Test etc. The field test includes cone penetration test, standard penetration test & vane shear test. All above those, the most common method is Triaxial Compression Test.MSW has complicated constituents ,high heterogeneity, and contains a lot of organic matters. The range of particle size is large; the void ratio is changed with the depth and the duration of the landfill. The degradation changes with time and it can effect the particle size and void ratio of MSW. Particle size,void ratio and degradation are the main affecting parameters of the MSW.The principal tasks are as follows.(1) CD shear tests were conducted using medium-scale triaxial apparatus on MSW samples of similar gradation while deferent particle size, in order to research the size effect of MSW in Triaxial Compression Test.(2) MSW samples are simulated the compositions of MSW from Hangzhou Tianziling landfill in deferent void ratio. CD shear tests were conducted using medium-scale triaxial apparatus on these MSW samples to study the influence of void ratio to MSW.(3) Because the degradation of MSW is to long, it is difficult to obtain massive deep degradation MSW samples. Simulated materials were sampled and tested according to the characteristics of real old MSW and the results of triaxial tests. Research showed that it is feasible using simulated materials to investigate the characteristics of old MSW, Based on the simulated materials, CD shear tests were conducted by deferent degradation MSW samples. Attempt to research the influence of the degradation to MSW.(4) The Test data processing method is the bilinear strain hardening model, to further verification applicability and rationality of the bilinear strain hardening model.(5) The experiment study results could be used in solid liquid gas coupled model, and it lays a theoretical foundation for the numerical method of landfill stress and deformation analysis.