Cable Force Analysis with the Constraint by Guide-Pipe −Vibration Measurement by Wireless Sensing Technology

Cable Force Analysis with the Constraint by Guide-Pipe −Vibration Measurement by Wireless Sensing Technology

Around the deck and the pylon of a cable-stayed bridge, there are two-to-three-meter-long guide-pipes protecting the cable tendons. With rubber damper inside, the guide-pipes reduce the vibration induced by wind, stem the flow of rain into anchors, and therefore increase the service life of the anchor system. From the viewpoint of cables, the guide-pipe constrain the free length of cables and affect the natural frequencies of the cables so that the engineers tend to overestimate or underestimate the true cable force by any theories or models without guide-pipe effect. To analyze the cable force more precisely, this paper utilize FEM method by considering both the mode shape and the frequency spectrum of a cable measured by wireless sensing technology. Through the inverse calculation process, the effective constraint imposed by guide-pipes and the precise cable force are quantitatively analyzed.