Study On Stability Analysis Of Reinforced Soil Retaining Walls

Reinforced soil retaining walls,which are quite capable of resistance to deformation and earthquake motion,have been used widely in our country.But,in the real engineering application,this technique is based on some experients,theoretical research is behindhand of engineering practice.FLAC program,which is based on explicit Lanrangian difference method mainly using discrete model method,dynamic relaxation method and explicit difference method in solving progress.So,the program can solve geotechnical problems quickly and accurately using realitive lesser calculative resource,especially the FOS solving module,it is applicable for stability analysis of geotechnical structures.In this paper,FLAC/2D4.0 program is used to do a series of stability analysis of reinforced soil retaining walls by the shear strength discount method.The failure pattern and failure mechanism of reinforced soil retaining walls were studied in order to give some help for engineering design and construction.Firstly..rational grid density was checked when using FLAC program to do stability analysis of geotechnical structures,and effects of reinforcements'layout and face plate on reinforced slopes' stability was analized also;Secondly,the stability analysis of reinforced soil retaining walls was done,it verifying main kinds of failure pattern by numerical method and finding the failure mechanisms of these kinds of failure pattern,then the unitized mathematic representation for potential sliding surfaces was maked,the potential sliding surfaces by analysis was fitted;Thirdly,it doing sensibility analysis of constants in the stability analysis of reinforced soil retaining walls and study of rationl design,effects of kinds of elements to the stability of reinforced soil retaining walls and rule of them were analized;Finally,for the design and construction of reinforced soil slopes and reinforced soil retaining walls,it giving some concept suggestions.The main research conclusions are remarked as follows:(1) For reinforced soil slopes,when reinforcements are short and sparse,the effects of reinforcements is feeble,as the renforcements getting long and dense,the fos of reinforced soil slopes getting large.But,when reinforcements getting the definite length and density,as the renforcements getting long and dense,the increment of fos is getting small;(2) Two main kinds of patterns were verified by numerical method,they are overturning failure and rotational sliding failure.The rotational sliding failure is caused mainly for the yielding of reinforcements.But,the overturning failure is caused mainly for large deformation between soil and reinforcements,which making the extraction of reinforcements fromsoil,these making walls unstable.The layout of reinforcements and material property of soil and reinforcements are the main influencing factors;(3) The multiplex line of log-spiral line with straight line can simulate potential sliding surfaces effectively .The factor of safety of wall is corresponding to the failure patterns of walls,it is small when the wall making overturning failure,but large when the wall making rotational sliding failure.The value of factor of safety is coherent with the layout of reinforcements and material property of soil and reinforcements too;(4) The material property of soil and reinforcements,contact relationship of soil and reinforcements can* affecting the stability of reinforced soil retaining walls on different level.The face plate is important to stability of reinforced soil slopes and retaining walls,the rational layout of reinforcements can increasing economic benefit and ensuring projective quality.