Measuring the exact cable tension force is important to cable supported bridge under construction and on service. This study was planned to propose EM(electro-magnetic) sensor-based method for measuring the tension force of MS(multi-strand) cable in cable-stayed and extradosed bridge. The tension force in each strand is the same due to MS cable construction using Iso-tensioning system. Therefore, In this prosed method, EM sensor was installed directly at a strand and the measurement model was established for estimating the tension force of strand via EM sensor by experiments. The measurement model was derived from the relation of tension force and magnetic permeability. Also, the magnetic permeability is shown to be different according to the magnetization characteristic of 1860MPa and 2200MPa high-strength strand. The difference is increased as tension force increases. Additional experiment was conducted to verify the measurement model. As a result, the distribution of strand tension calculated upon the EM sensor is similar to those of tension measured by load cell. This proposed approach can be an effective tool for monitoring and measuring the cable force of MS cable.

1. 서 론
 2. EM 센서
 3. 보정실험
  3.1 고강도 강연선
  3.2 실험구성/방법
  3.3 실험결과
 4. 결 론
 REFERENCES

• 박원태(공주대학교 건설환경공학부 교수) | Park Weon-Tae
• 천경식(포스코건설 R&D센터 책임연구원) | Chun Kyoung-Sik Corresponding author
• 송수용(포스코건설 인프라사업본부 과장) | Song Su-Yong