Journal of the Korea institute for structural maintenance and inspection (한국구조물진단유지관리공학회 논문집)
- Volume 7 Issue 2
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- Pages.247-261
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- 2003
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- 2234-6937(pISSN)
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- 2287-6979(eISSN)
Behaviour of Truss Bridges by Using the Post-tensioning
후긴장을 이용한 트러스의 성능 향상 평가
- Jeung, Bae-Keun ;
- Han, Kyung-Bong ;
- Eom, Jun-Sik (Michigan University Department of Civil Engineering) ;
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Park, Sun-Kyu
- Received : 2002.11.18
- Published : 2003.04.30
Abstract
The technique of posttensioning has been used successfully to improve the performance of existing concrete structures. However, very few applications of this technique can be found in steel structures. Posttensioning by means of high strength cable or bar can be used to effectively increase the working load capacity of Truss Bridges. The benefits of posttensioning trusses can be achieved in strengthening of existing structures as well as in the design of new structures. In this paper, the elastic behavior of posttensioned trusses with straight and draped tendon profiles is examined. For the analysis of posttensioned trusses in the elastic range of behavior, two methods are presented, namely, the flexibility method and the mixed-method, i.e., a combination of the stiffness and flexibility methods. Using the presented methods, the effects of design variables such as the tendon profile, truss type, prestress force, and tendon eccentricity on the working load and deflection of trusses are studied. The results show that the allowable load of truss increases proportionally with increase in prestress force and eccentricity. Posttesioning enlarges the elastic range, increases redundancy, and reduces deflection and member stresses. Thus, the remaining life of a truss bridge can be increased relatively inexpensively.
Keywords
- posttensioning;
- posttensioned plane trusses;
- prestressing force increments;
- flexibility method;
- mixed-method;
- design