The FEM Analysis On Asphalt Pavement Working Condition Of Reinforced Concrect Bridge

The bridge deck pavement system, which is bearing the vehicle load and surrounding environment, is the structural layer and protecting layer of the bridge. Proper design of the bridge deck pavement will provide enough capability for bearing the load, improve the durability of deck and prolong the service period of bridge.In this thesis, the working condition under environment of two layer asphalt bridge deck pavement is analyzed by the FEM software ANSYS. The stress and strain distribution under force, the temperature distribution under varied air temperature and radiations are calculated. On these bases, the affects of the pavement temperature changes are analyzed.From the FEM result in constant temperature, the maximum shear stress and the maximum tensile stress result in destroy of bridge deck majorly. Under various air temperature, the pavement temperature amplitude is larger the air temperature. In one hand, the temperature change of pavement affects the Young's Modulus, in another the gradient of temperature change at the same time. From analytic, the pavement working condition changes obviously. The shear stress, tensile stress and pressure stress under variable temperature are bigger than the corresponding value of the constant temperature because of the temperature sensetivity of asphalt material. In 24 hour, the magnitude of displacement and strain change is notable. The maximum values are found at high temperature. The magnituded of stresss is not so notable as displacement and stresses. The affect of tensile stress is more significant than compressive stress. Therefore, the variety of pavment should be considered in the calculation of pavement working condition to properly simulate the acutural status. As a result, the temperature affect will be considered in the design of the pavement and the result of the constant temperature should be corrected according to temperature.By contrast of the FEM simulation result and test measurement value, the strain value of FEM simulation of elastic material could inflect the strain change of dymanic loading stage. The model with Time Hardening Creep Equation model simulates the strain in the stactic loading stage. The plastic stage is simulated by Drucker_Prager criterion and the strain in that stage is significantly bigger than the elastic one.