机场刚性道面板底接触状态感知与评价

The contact condition deterioration is an important factor that result in slab cracking and faulting of airport rigid pavements. The findings of the previous NSF project show that the dynamic response of rigid pavement is very sensitive to the contact condition, and poor contact will significantly shorten the service life of airport rigid pavements. Nevertheless, the traditional measurement technologies can hardly get the real contact condition beneath slabs in terms of identifying the cavity distribution, uneven supporting and deterioration degree. In this research, the multi-scale tests and three-dimensional numerical simulations will be adopted to investigate the dynamic mechanical responses and vibration modes caused by different contact conditions. Combining the pressure sensing and vibration sensing methods, a distributed optical fiber sensing system will be developed to detect the contact condition. Moreover, a spatial analytic method will be proposed to extract real contact conditions from the measured strain and vibration data, on the basis of dimension translating and temperature calibration. The correlation model between optic fiber measurement and pavement response will be established based on simulation and laboratory testing. Meanwhile, the real time assessment and method for evaluating the contact condition beneath pavement will be proposed. From this research, the scientific problems of sensing, analyzing, and evaluation of the contact condition will be solved, and the airport rigid pavement design method and evaluation technology can be improved.

机场刚性道面板底接触状态弱化是引发断板、错台等病害的重要因素。申请人通过前一个国家自然科学基金项目，对刚性道面结构动力行为的研究发现，道面结构动力响应对板底接触状态十分敏感，不良接触将严重缩短道面使用寿命。然而，传统的测试技术难以实时、全面地获取和判别板底接触状态的分布范围、不均匀特征及弱化程度。本项目通过多尺度试验和三维数值仿真，揭示不同板底接触状态对刚性道面结构动力响应及振动模态的影响规律；综合压力感知和振动感知，研发刚性道面板底接触状态的分布式光纤感知技术；基于光纤应变、振动数据的变维解析和温度修正，开发刚性道面板底接触状态的空间解析技术；通过仿真模拟和试验实证，建立光纤感知信息与道面动力学响应的映射关系模型。在此基础上，提出基于实时感知的板底接触状态评价指标和方法。从而解决刚性道面板底接触状态感知、解析与评价等科学问题，为改进机场刚性道面结构设计方法和评价技术提供支撑。

机场刚性道面板底接触状态弱化是引发断板、错台等病害的重要因素。为实时、全面地感知和评价机场道面板底接触状态，本课题在接触状态影响机理、接触状态感知技术、接触状态评价方法等三方面开展研究。首先通过多尺度试验和精细化三维有限元仿真，揭示了板底接触状态对道面结构力学响应、振动模态的影响机理；随后面向道面结构的板底接触状态感知与评价，利用分布式光纤传感技术，分别构建了分布式板底接触压力感知系统和分布式道面板振动感知系统，并提出了压力感知元件的设计方法、振动传感光纤的布设方法，研发了包括数据预处理、压力特征提取、振动频谱解析的分布式光纤数据解析方法，可实现大范围板底接触压力分布状态感知和道面板局部振动特征提取。在此基础上，利用足尺试验平台设计了不同接触状态的试验工况，基于多种感知数据提出了可适应不同应用场景是板底接触状态评价方法和评价流程，并于上海市龙华机场、成都市天府国际机场开展了实测验证。研究成果可为改进机场刚性道面结构设计方法与评价技术提供支撑。