Study On Settlement Deformation Of Rheological Clay Foundation Under High Filled Subgrade

The terrain of Guizhou province is undulating,so road construction often requires high filling.The red clay which is formed by the weathering of exposed carbonate rocks is the main composition of the soil layer,and rheologic characteristics of clay is more significant.Combining with the characteristics of road construction in Guizhou,using ABAQUS software to build a model research on the settlement deformation of clay ground with rheologic characteristics under high filled embankment,in order to providing a scientific basis for the decision making of road design and construction.With the help of the data extraction,plotting,fitting abilities of Origin9 and1 st Opt software and the powerful modeling and analysis abilities of ABAQUS software,the main research work and results are as follows:1.Calculation principle and procedure of the stratified summation method are summarized,and the common models of curve fitting method are introduced.Through the analysis of calculation example,the paper studies the settlement prediction principle of curve fitting method.On the basis of the previous studies,the advantages and disadvantages of the three methods are analyzed,it is considered that finite element method is most suitable for the study of this topic.2.Linear elastic model and plastic model involved in building the cross section model of high filled road are introduced.By studying on a large number of creep tests,classify the types and stages of soil creep and analyze its mechanism.Next this paper introduces the rheological model theory and deduces the constitutive equations of the basic rheological models.Based on the theory of fractional calculus,a visco-elasticplastic creep model suitable for describing the creep law of clay is proposed,it provides a tool for studying the field of soil settlement’s creep analysis.3.Briefly describing the three stage mechanism of ground settlement and the causes of creep analysis,then the creep parameters of clay are calculated by fitting the creep test data.4.A cross section model of high filled road is established in the ABQAUS software by using the creep parameters of clay and physical-mechanical parameters ofmaterial,and the settlement characteristics of clay foundation are analyzed.Then the paper establishes a comparative model that considers the creep factors in accordance with the basic model,the calculation results show that: The influence of creep factor on the post construction settlement at the end of 10 years of the foundation and subgrade top center is 26.6% and 27.9% respectively.The impact is more significant and creep factor should be considered in the settlement calculation.5.Three groups of eighteen subgrade layered filling schemes are designed,and correspond to building numerical model for high filled road under 18 conditions.Results show that: The subgrade layered filling scheme has a significant impact on the post construction settlement of ground,reducing the filling speed or increasing the consolidation time of the construction gap can reduce the post construction settlement of ground.The reduction rate of ground settlement shows an increasing deceleration trend as the filling speed decreases and the clearance consolidation time increases./cbeay-x(10)(28)can be used to accurately fit the curve between post construction settlement,subgrade filling rate and clearance consolidation time.The value of post construction settlement under different subgrade filling schemes can be estimated as a.6.Based on the research results of the finite element model,seven suggestions are given for the construction of high filled road in Guizhou province.