|
Fatigue Behaviour of the Upper End of Vertical Stiffener Connected with Sway Bracing |
|---|---|
| รหัสดีโอไอ | |
| Title | Fatigue Behaviour of the Upper End of Vertical Stiffener Connected with Sway Bracing |
| Creator | Chihiro Sakamoto, Masahiro Sakano |
| Contributor | - |
| Publisher | ISEC PRESS |
| Publication Year | 2560 |
| Keyword | vertical stiffener, fatigue test, thread rolling screw, jack up |
| Abstract | Lots of fatigue crackings were reported at the upper end of vertical stiffeners connected to intermediate bracings in steel highway girder bridges. Several countermeasures were proposed against those crackings, such as steel plate reinforcement between the upper flange and the vertical stiffener using high tension bolts after breaking RC slab, or re-welding. However, the work of breaking RC slab requires traffic lane closing, and re-welding may cause re-cracking. Then, some steel plate reinforcement methods using a jack-up jigs were proposed, in which traffic lane closing should not be required. But it has not been verified how effective in stress reduction and fatigue life extension.In this study, we investigate fatigue behaviour of the upper end of vertical stiffener connected with intermediate bracing, through fatigue tests using a full-scale specimen with three main girders under alternative loading using two actuators. As a result, alternative loading can reproduce the alternative stress at the upper ends of vertical stiffener in the middle girder under vehicles run on the true traffic lane and passing lane. In fatigue tests, root and toe cracks occurred after 0.1 to 1.6 million cycle loading, and it is confirmed that root cracks tend to be developed when the root width is large.Further studies are required on retrofitting methods against fatigue cracking at the upper end of vertical stiffener connected with intermediate bracing. |
| ISBN | 978-0-9960437-4-8 |
