3-D overlay model of broken concrete pavement

When reconstruct old portland-cement-concrete pavement, the old pavement needs to be broken, the regular layer's continuous model doesn't match with the broken pavement, so a (3-D) overlay structure model was developed with finite element method. In the model, the overlay and subgrade's deflection is continuous, the broken pavement deflection is not so, the deflection between upper and low layers might not be continuous. The analyzing results show that there is an empty space among the overlay, broken pavement and subgrade; the broken pavement's deflection is dual linear distribution, the low deflection basin still contains the upper deflection basin; there is a deflection difference in the two sides of the broken pavement's seam, there are moment and shear differences in the overlay. To the disconnection rigid or half-rigid subgrade pavement structure, the model is a feasible calculation method.