人行吊橋背拉鋼索索力之動態應變式監測計

For the cable-supported bridge, like the suspension bridges and cable-stayed bridges, cables are the main component for the safety and comfortability of the structure. Hence, the cable force monitoring is an important issue to ensure the maintenance and management of the bridge. The vibration method is widely used for the cable force measurement since its advantage includes non-invasive and easy to operate. To reduce the cost of monitoring, this paper uses a resistance type strain gauge to measure the natural frequencies of the cable and back calculate the cable force. Experiments including the vibration of steel bar, the vibration of pre-stressed cable, field measurement at a suspension footbridge. Experimental results confirm that a resistance type strain gauge can effectively measure the natural frequency of the cable, which can be used to evaluate the existing cable force.