This paper presents the test results between the Elasto-magnetic (EM) sensor and the vibration method that are able to monitor the forces in the cables of cable-supported bridges. EM sensor is a practical application of Faraday’s law, and the vibration method is the most popular technique based on the natural frequency of the cables and the string theory. EM sensor has advantages that there is no limitation of geometric conditions such support, length of cable, and sag effect, because the sensor relies on the material property itself. An inclined parallel wired strand (PWS) cable of 44 meter long and 80 mm diameter installed from reaction wall to floor is used as a specimen which is the same with one of original cables applied to a cable-stayed bridge in Korea. The EM sensor is fabricated at the arbitrary position over the polyethylene (PE) cover, and an accelerometer is located at a quarter positions. The accuracy is confirmed through the load cell readings. Above 5% of allowable stress, it is less than ±1.1%.

Related Publications