Kapogianni Elena, Sakellariou Michael
Laboratory of Structural Mechanics, National Technical University of Athens, 157 80 Athens, Greece.
Sensors (Basel). 2025 Feb 27;25(5):1450. doi: 10.3390/s25051450.
The current study investigates the feasibility and performance of Fiber Bragg Grating (FBG) optical sensors in geotechnical engineering applications, aiming to demonstrate their broader applicability across different scales, from controlled laboratory experiments to real-world field implementations. More specifically, the research evaluates the sensors' ability to monitor key parameters-strain, temperature, and acceleration-under diverse loading conditions, including static, dynamic, seismic, and centrifuge loads. Within this framework, laboratory experiments were conducted using the one-degree-of-freedom shaking table at the National Technical University of Athens to assess sensor performance during seismic loading. These tests provided insights into the behavior of geotechnical physical models under earthquake conditions and the reliability of FBG sensors in capturing dynamic responses. Additional testing was performed using the drum centrifuge at ETH Zurich, where physical models experienced gravitational accelerations up to 100 g, including impact loads. The sensors successfully captured the loading conditions, reflecting the anticipated model behavior. In the field, optical fibers were installed on the Perimeter Wall (Circuit Wall) of the Acropolis of Athens to monitor strain, temperature, and acceleration in real-time. Despite the challenges posed by the archaeological site's constraints, the system gathered data over two years, offering insights into the structural behavior of this historic monument under environmental and loading variations. The Acropolis application serves as a key field example, illustrating the use of these sensors in a complex and historically significant site. Finally, the study details the test setups, sensor types, and data acquisition techniques, while addressing technical challenges and solutions. The results demonstrate the effectiveness of FBG sensors in geotechnical applications and highlight their potential for future projects, emphasizing their value as tools for monitoring structural integrity and advancing geotechnical engineering.
本研究调查了光纤布拉格光栅（FBG）光学传感器在岩土工程应用中的可行性和性能，旨在证明其在从受控实验室实验到实际现场实施的不同尺度上具有更广泛的适用性。更具体地说，该研究评估了传感器在包括静态、动态、地震和离心机载荷等不同加载条件下监测关键参数——应变、温度和加速度的能力。在此框架内，在雅典国立技术大学使用单自由度振动台进行了实验室实验，以评估地震加载期间传感器的性能。这些测试深入了解了岩土物理模型在地震条件下的行为以及FBG传感器在捕捉动态响应方面的可靠性。使用苏黎世联邦理工学院的鼓式离心机进行了额外测试，物理模型在那里经历了高达100g的重力加速度，包括冲击载荷。传感器成功捕捉到了加载条件，反映了预期的模型行为。在现场，光纤被安装在雅典卫城的周边墙（环墙）上，以实时监测应变、温度和加速度。尽管考古遗址的限制带来了挑战，但该系统在两年多的时间里收集了数据，提供了关于这座历史古迹在环境和荷载变化下结构行为的见解。雅典卫城的应用是一个关键的现场实例，说明了这些传感器在复杂且具有历史意义的地点的使用情况。最后，该研究详细介绍了测试设置、传感器类型和数据采集技术，同时解决了技术挑战和解决方案。结果证明了FBG传感器在岩土工程应用中的有效性，并突出了它们在未来项目中的潜力，强调了它们作为监测结构完整性和推进岩土工程工具的价值。
