Material Characterization of the Pavement Structure Using FWDT, a Non-Destructive Testing Technique

当反复的车辆荷载和环境影响导致路面结构的多重劣化时，路面结构达到使用极限。因此，获取有关路面结构状态的详细信息是对出现严重损伤的路段进行修复规划的重要因素。无损检测(NDT)方法已被广泛用于结构健康监测和交通运输中的低成本评估。落锤式弯沉仪(FWD)是表征路面结构力学性能最常用的无损检测技术之一。FWD测试测量了已知质量从特定高度坠落时所造成的表面偏转。路面结构中水分的存在会显著影响路面的使用性能。路面养护的另一个重要问题是寒冷地区的季节性因素。基于采集到的地表位移数据，利用反演算法可以确定构成多层柔性路面系统的各层的力学性质。目前该方法的实际应用水平仅限于最大实测挠度的准静态反演。然而，这种方法没有利用应力波时程中包含的附加信息，如阻尼、含水率和多孔结构的影响。采用综合的动态分析而不是准静态分析，也将提高确定各层力学性能的准确性。这项研究的目标是通过基于最小二乘的反演技术开发一种路面结构材料表征的算法。FPrimeC Solutions专门设计和开发创新的无损检测设备和结构健康监测系统，用于测试材料和结构。FPrimeC感兴趣的是开发一种创新的算法，使用FWD来评估路面结构的材料特性，以获得更准确和更可靠的信息。

Pavement structures reach performance limits when there are multiple deteriorations caused by repeatedvehicle loading and environmental effects. Therefore acquiring detailed information about the state of thepavement structures is an important element in rehabilitation planning of sections showing significant damage.Non-Destructive-Testing (NDT) Methods have been broadly used for structural health monitoring and low-costassessment in transportation. Falling Weight Deflectometer (FWD) is one of the most popular NDT techniquesin characterisation of the mechanical properties of the pavement structure. The FWD test measures the surfacedeflections caused by dropping a known mass from a specific height. The presence of moisture in the pavementstructure can significantly affect the performance of the pavement. Another important issue to the pavementmaintenance is the seasonal factor in cold regions. The mechanical properties of the layers constituting themultilayered flexible pavement system can be determined by using a back-calculation algorithm based onacquired surface displacement data. The current practical state-of-the-art of this method is limited to thequasi-static inversion of the maximum measured deflections. However, this approach does not take advantageof the additional information contained in the stress wave time histories such as damping, moisture content,and the effect of porous structure. The accuracy of determining the mechanical properties of the layers wouldalso improve by using a comprehensive dynamic analysis rather than a quasi-static analysis. The objective ofthe proposed research is to develop an algorithm for the material characterization of the pavement structurethrough a least square-based inversion technique.FPrimeC Solutions specializes in the design and development of innovative Non-Destructive Testingequipment and Structural Health Monitoring Systems for testing materials and structures. FPrimeC is interestedin developing an innovative algorithm to achieve more accurate and more reliable information using FWD toevaluate the material properties of the pavement structure.