헤테로코어 광섬유 센서를 이용한 쉬스관 일체형 센서 모듈의 기초 성능 확인 실험

Abstract

The PSC method can compensate for the weakness of concrete that is weak in tension, and not only can the cross-section of the member be reduced than reinforced concrete, but it can also be used in a wide range of fields such as long bridges, skyscrapers, parking lots, and containment structures. In the case of overseas advanced countries' promotion of bridge construction, the PSC method is accepted as the best method in safety, economic efficiency, usability, management, and aesthetics, and is used in various fields, including bridges. However, with many applications, the number of old PSC bridges is also increasing. Bridges with more than 20 years of public experience account for 24.2% of the total PSC girder bridges, and as the proportion of vulnerable old facilities increases in the future, it is urgent to prepare effective management measures. Therefore, in order to proactively manage PSC bridges, it is necessary to develop new technologies that can monitor prestress, a key element of PSC bridges, in real time during the bridge's life cycle. This study aims to confirm the basic performance of a sensor module for measuring prestress using an optical fiber sensor as a sensing device to evaluate prestress introduced into a PSC structure. Optical fiber sensors are small, light, and flexible, making it easy to install anywhere, and have the advantage of not affecting temperature or electromagnetic fields. The hetero-core optical fiber sensor can be measured by linking external deformation and curvature changes through a linear change in the amount of light leakage according to the change in curvature of the hetero-core part. Two experiments were conducted to confirm the performance of the sheath tube integrated sensor module using the PSC beam experiment. The first experiment confirmed the sensor's response characteristics to compression deformation of the structure by introducing tension to the PSC beam experiment in a post-tension manner, and the second experiment confirmed the sensor's response characteristics to tensile deformation. As a result of the experiment, it was confirmed that the sensor's power measurement value was clearly divided and measured for compressive and tensile deformation generated in the test body due to the introduction of tension and load loading. The results of this study show that it is possible to directly evaluate the prestress of PSC structures with sensor modules using the characteristics of hetero-core fiber sensors, and it is believed that it can be used as useful data for developing more practical sensor modules in the future.