Research On Reinforcement Mechanism Of Geosynthetics And Stability Analysis Of Reinforcement Slope

The deformation and stability of dyke body and dyke foundation are the main controlconditions for sea embankment built on soft soil foundation.Geosynthetics reinforcementmeasures is the most common method to reinforce the dyke due to its easy construction, obviousstrengthening effect and low cost advantages in many aspects.Based on the merit of the tensileperformance of geosynthetics and the merit of the compressive resistance of grit,some certaingeosynthetics can be paved in the body or foundation of dyke to make use of the combinativeeffect to restrict the lateral deformation of soft soil.This effect can also improve the integralstability of geotechnical structures by means of changing the stress and displacement fields insoil.This paper is relying on the Xingjin river&Waisha river estuarine regulation andcomprehensive development project of Shantou eastern part.Based on the existingresearch results,the study on the friction characteristics of interface between geosynthetics andsand has been discussed.Meanwhile this paper analyzes the stress-strain features and strengthcharacteristics of reinforced soil through direct shear test and pull-out test in laboratory.On thebase of reinforce mechanisms,the stability analysis model of reinforced slope was establishedand theoretic analysis and numerical calculation was made for a simplied slope model in actualproject.On the base of the extensive collection of data and the introduction of geosynthetic researchstatus,the main contents presented in this thesis are summarized as follows:1.From the actual engineering background， this paper analyzes in detail the frictionalreinforcement theory,the pseudo-cohesion with lateral restriction theory and shear zones theoryof reinforced soil.2. The friction characteristics of interface between different geosynthetics and sand havebeen discussed,and the stress-strain features and strength characteristics of reinforced soil areobtained through t direct shear test and pull-out test in laboratory.The influencing factors ofinterface characteristic including sand density and shear rate are analyzed by means of changingthe test conditions.3.According to the integral stability analysis methods of reinforced slope in current codes which was based on ultimate equilibrium theory,this paper proposes the integral stabilitycalculating models of reinforced slope based on frictional reinforcement theory,thepseudo-cohesion with lateral restriction theory and shear zones theory.Firstly,this paper analysesthe integral stability of a practical simplified slope through slice method of ultimate equilibriumanalysis method,then the integral stability contrast analysis of this slope model is made throughstrength reduction method of finite element method.Finally,the author’s suggestion for theapplicability of these calculating methods is given through the comparison of these calculatedresults.4.The deformation property of the embankment is analysed through using the same finiteelement analysis model,and the variation of the deformation for dyke on soft ground isobtained.Finally,the situs that need to be reinforced and the reasonable form of laying ongeosynthetics are proposed through these calculated results above.