The Research Of MSW Landfill Slope Stability Based On The Biodegradation

Garbage is municipal solid waste produced in human daily life and production.With the development of urban and rural integration and the progress of social and economic,more and more people move to cities making the gradual increase of urban population so that the city garbage and life waste production in increasing.Therefore the disposal of garbage is important measure of the city’s stable development and personal health.In our country,the garbage processing method is main landfill.Landfills become most economic and efficient urban garbage treatment method in our country because landfills have some advantages such as,reliable technology,economic,convenient and wide.The most important for landfill is stability of the slope,if the slope is instability,which causes a serious of loss of our society economy and personal security.So,the slope stability study of the landfill is very important in order to protect people’s life safety and reduce the economic loss.And it has great important mean for protecting environment.The background and progress of slope stability analysis is elaborated both domestic and foreign,and the type and mechanization of slope failure is discussed.Moreover,related yield criterion and slope stability analysis method commonly used at home and abroad are introduced,which mainly include the limit equilibrium analysis method and numerical analysis method.Due to the biological degradation,the strength parameters of landfill in different depth are not the same.More time more long garbage dumped,which’s degree of degradation is depth and strength parameter is larger,so it was studied.With the rapid development of modern science and technology,numerical simulation method based on computer also rapidly developed.MSW samples are determined from indoor and outdoor experiment,which confirmed the basic physical and mechanical parameters of landfill that is used for numerical simulation analysis.And slope stability is analyzed from slope stability analysis method and finite element software FLAC3 D when the landfill is used and finished.The main research conclusions are as follows:(1)The slope stability of landfill is studied from FLAC3 D numerical simulation.The same time,fully considering the factor that landfill waste organics degrades because of biodegradation so that garbage’s soil parameters are different in different depth.Then,slope stability is simulated in the case of landfill layered.(2)The stress and displacement of slope simulated are analyzed,which is found that the maximum vertical displacement is more concentrated in the top position of slope.And the maximum displacement is-4.93m;while the horizontal direction displacement are more concentrated in the slope near the foot of slope,and the maximum displacement value is-8.66 m that the negative value indicates the direction is contrary to the initial set.However,the magnitude of stress not only horizontal but also vertical direction increases with the increase of depth.(3)Landfill slope stability of stratification is detailed studied to get the plastic region and the sliding surface.At last,the safety factor is 1.64 after closure of landfill,which conforms to relevant regulations.And the safety factor in process of operation is reduced with the increase of landfill’s elevation.