Dynamic Response Analysis of Void Under Slab to Cement Concrete Pavement

To analyze the dynamic response of void under slab to the cement concrete pavement, base on fluid-structure interaction theory, and the finite element model of nine cement concrete pavements which considered the interaction of plate and plate was set up, the influence to the pavement structure of vehicle parameters (uniform quality, function area and movement speed), pavement plate parameters (thickness of pavement plate, distributed rebar of longitudinal seam and cross seam, etc) and foundation void under slab (different void areas, different position and the different water contents of void position) were analyzed under the driving load. The change rules of the dynamic deflection, maximal flexural-tensile stress and water pressure of nine cement concrete pavements which were set rebar at the seams were delved. Results show that no matter whether there is the void, the deflection, flexural-tensile stress and water pressure of cement concrete pavement top surface of the slab corner void area are obviously greater than that of the longitudinal joint void area. The deflection and flexural-tensile stress increase with the increasement of void area. The different water contents of void area have little effect on the deflection and flexural stress of the slab. With the void area increasing, the water pressure of void area bottom of the base course shows the linear growth trend. The water pressure which is in the corner void area of the slab is significantly greater than that of the longitudinal joint void area.