半刚性基层沥青路面非连续结构强迫振动声效

Sound analysis of forced vibration feature of discontinuous structure in semi-rigid base asphalt pavement

为了无损、快速地识别半刚性基层沥青路面的结构非连续状态,实现病害预警和预养护,对冲击作用下路面板体强迫振动机理及其振动噪声特征进行了分析,并对单自由度路面系统的强迫振动微分方程进行求解.研究表明:因土基沉降、低温施工、压实不足等原因,沥青路面将产生结构内部及层间非连续病害;而非连续状态下的板体强迫振动噪声特征对冲击加载方式、板体尺寸、模量、非连续区域面积等因素最为敏感;通过有限元声场模拟确定路面非连续性有效识别冲击力为1.0 kN,可识别最大非连续面积为4 m×4 m,最显著强迫振动噪声能量集中在300～800 Hz频带内.

In order to identify the discontinuous state of semi-rigid base asphalt pavement structure nondestructively,rapidly,and realize the pavement disease prediction and preventive maintenance,the forced vibration mechanism and noise character in pavement structure under impact loading were analyzed,and forced vibration differential equation for single degree of freedom pavement system is solved.It is shown that the discontinuous disease in the asphalt pavement structure and interlayer comes from foundation settlement,low temperature construction,insufficient compaction and so on,and forced vibration noise character of the pavement are most sensitive to impact loading manner,pavement size,modulus,and the discontinuous area.Finally,by means of finite element simulation of sound field it is ascertained that the impact force of 1.0 kN is effective to identify the pavement structure discontinuity,and the maximal recognizable discontinuous area is 4 m×4 m,and the majority of forced vibration noise energy is concentrated in the band of 300-800 Hz.