人行吊橋背拉鋼索索力之動態應變式監測計

CABLE FORCE MONITORING OF PEDESTRIAN SUSPENSION BRIDGE BY RESISTANCE TYPE STRAIN GAUGE

王仲宇(Chung-Yue Wang) ； 邱繼正(Ji-Zheng Chiu) ； 陳志賢(Chih-Shian Chen) ； 王顥霖(Hao-Lin Wang)

《中國土木水利工程學刊》 32卷7期 (2020/11) Pp. 585-595

https://doi.org/10.6652/JoCICHE.202011_32(7).0002

摘要

對吊橋等具鋼纜構件橋梁而言，纜索為其重要的受力部分。因此，索力之監測為此類橋梁安全性確保的重要手段。而在監測索力的諸方法中，振動法由於具有非侵入性、操作簡便且能得到足夠精確之結果等優點，而被廣泛運用。為了減少監測儀器成本，本研究嘗試以電阻式應變計作為量測自然振動頻率之工具，進行包含鋼棒振動實驗、預力鋼絞線振動實驗，及人行吊橋的現地量測等可行性驗證實驗。實驗結果證實，電阻式應變計可正確量測出纜索的自然振動頻率，進而評估纜索之現有索力。

關鍵字

吊橋 ； 索力監測 ； 振動法 ； 自然振動頻率 ； 電阻式應變計

並列摘要

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.

並列關鍵字

cable force monitoring ； suspension bridge ； vibration method ； natural frequency ； resistance strain gauge