沥青路面阻尼特征参数及路表动态弯沉盆分布特征研究

Study on Damping Characteristic Parameters and Distribution Characteristics of Surface Dynamic Deflection Basins of Asphalt Pavement

为解决沥青路面模量参数反演时有效动态理论弯沉盆数据获取问题,采用动力有限元数值分析方法,探讨了结构层材料阻尼参数的计算求解方法,建立了路基阻尼参数的预估分析模型,考察了测试荷载的动力效应以及层间非连续接触行为对路表动态弯沉盆的影响规律。研究结果表明:路基阻尼参数是影响路表动态弯沉分布的重要因素,并受路基模量的影响最为显著,而其他路面结构层参数对其影响可以忽略不计;FWD动静荷载作用下沥青路面路表弯沉盆的分布规律明显不同,相同的路面结构层间接触状态不同,路表弯沉盆的分布规律也存在着明显的差异;有效的结构层模量参数反演分析应充分考虑FWD测试设备的动力特性,以及路面层间实际接触条件。

To attain the data of effective dynamic deflection basin utilized to implement modulus back- calculation of asphalt pavement, by dynamic finite element analysis method, the solution method of damping coefficients of pavement structural layers is discussed, the estimation model of subgrade damping coefficients is established, and the influence of testing loading＇s dynamic effect and discontinuous contact behavior between structural layers on distribution features of surface dynamic deflection basin is investigated. The results demonstrate that （1） subgrade damping coefficient is a main factor affecting surface dynamic deflection distribution, which is mainly controlled by subgrade modulus, while the influence of other structural parameters on subgrade damping coefficient is negligible; （2） when the asphalt pavement is imposed by static and dynamic loadings, the distribution features of dynamic deflection basin has a pronounced difference, and different interface contact conditions result in different distribution patterns of dynamic deflection basin for the same asphalt pavement; （3） performing back calculation of modulus parameters of structural layers should consider the actual FWD loading characteristics and the interface contact behaviors.