Distribution Characteristics of Surface Dynamic Deflection Basin of CTB Asphalt Pavement with Cracking

In order to screen the effective data of FWD deflection basin in the back calculation of modulus parameters of asphalt pavement,the distribution features of dynamic deflection basins of semi-rigid base asphalt pavement with the different forms of crack damages is discussed by 3D dynamic finite element numerical analysis method.The selecting evaluation indicators and criterion of the effective data of FWD deflection basin are presented and verified by in-situ case study.The results demonstrate that(1) the crack gap value,0.2 mm,is the critical value to determine whether there is contact between crack surface of semi-rigid base asphalt pavement;(2) there is a significant difference of distribution patterns of dynamic deflection basin between intact pavement structure and cracked pavement structure;(3) the direct road surface deflection indicator and surface modulus indicator are reasonable and applicable for filtering the effective data of deflection basins.The research can provide practical support for modulus parameters back calculation of semi-rigid base asphalt pavements based on FWD testing technology.