Determination Criterion for Voids of Beckman Beam Static Deflection Based on Finite Element Simulation

On the basis of deeply analyzing determination methods for voids in current specifications of cement pavement, three-dimensional models were set up using the ANSYS finite element method for voids beneath slab corner and slab edge to calculate deflection values under different void depth, void area, and load transfer capacity. Relying on Yantai-Weihai expressway, detection data for deflection using Benkelman Beam were statistically analyzed. Referencing the results of computer simulation and analysis of static deflection test data, the determination method is proposed that using slab edge - slab center deflection difference and slab corner - slab center deflection difference to determine the voids, and the criteria are given. The criteria are verified by actual test data and contrasted with the methods of specifications. Results show that: the simulation values using ANSYS finite element accord with engineering actual values; the accuracy of void determination by lab edge - slab center deflection difference is 88.5%, the accuracy of void determination by slab corner - slab center deflection difference is 92.3%. Compared with the method of specification, the recommend values are better. Research can better guide the cement concrete pavement maintenance and rehabilitation.