Three-dimensional Numerical Analysis Of Stress Of Heterogeneous Cement Pavement Under Traffic Moving Loads

The advantage of the cement concrete pavement with high strength, and good stability,good durability,thermostability,wear resisitance and less cost on maintenance,but premature deterioration accrues in applications, it is main obstacles for further application of cement concrete pavement. So, it is significant, that gets more into mechanism of premature deterioration factors, and proposes measures of construction and design. This paper choosed structure of cement concrete pavement as the study object,develop three dimensional numerical modeling of cement concrete pavement under traffic loads with FLAC3D. So this paper have analyzed factors of load stress of cement concrete pavement: vehicle speed, non-planarity, interlayer adhesion and heterogeneity of concrete pavement, and,analyzed influence of stress of cement concrete pavement with temperature variation.Research contens:1) Cement concrete pavement is regarded as strain-softening material. And then, I supposed cement concrete’s modulus following Gaussion distributions, and set contract surface between pavement and base course of concrete pavement. Establish model of three-dimensional cement pavement with Matlab and FLAC3D, and this model considers condition of interlayer bonding and mechanics characteristic of heterogeneous.2) In this paper, I analyzed interface conditions and mechanics’heterogeneous characteristic of cement concrete pavement’s material, which having effect on load stress of panel bottom with established numerical model.3) Established numerical model which consider vehile loads,and Analyze speed of vehile and pavement roughness, which having effect on load stress of panel.4) Established cement pavement three-dimensional numerical model, which consider temperature and stress. Then I analyzed maximum plus temperature gradient, thickness of slab, the length of slab, the modulus of cement concrete, the modulus of base on cement concrete pavement, which have an effect on structure’s temperature stress.The result of numerical analysis indicated that:1) The mechanical heterogeneity of the cement structure layer material can lead to the road panel stress concentration,and that increases load stress. And base on heterogeneous material of cement concrete, when vehicle speed, nonplanarity is increasing,the load stress of cement concrete pavement is unconspicuous increasing. 2) Becase of interlayer adhesion, the load stress of cement concrete pavement is decrease, what’s more, the loads tress of cement concrete pavement is decrease with the cohesion increase. Then, the loads stress of cement concrete pavement is unconspicuous increasing with vehicle speed, non-planarity increase.3) Under the temperature gradient, the temperature stress of cement pavement is conspicuous increasing with the length of slab, the modulus of concrete increase, and the temperature stress of cement concrete pavement is unconspicuous increasing with the modulus of base increase, but the temperature stress of cement pavement is decrease with the modulus of base increase; because of interlayer adhesion, temperature stress is inceasing.