Ikitsuki Bridge †

↑

1.Field of application †

Ikituki Br. in Nagasaki, Japan.

↑

2.Circumstances of Repair †

Fatigue crack was found at the panel point of the diagonal member in Dec.2009 after 19 years of service.

↑

3.Types of structure †

The outline of the bridge structure is as follows.

Photograph of Ikitsuki Br. is shown in Fig.1.

File not found: "ikitsuki_1.jpg" at page "Shinkansen Br.(connections between stringers and floorbeams in steel railway trusses)"[ź]

Fig.1 Ikitusuki Br.
↑

4.Details of loading †

Fluctuating loads due to wind load.

↑

5.Description of damage †

The fatigue crack was found by the visual inspection.The crack location and detail are shown in Fig.2,Fig.3.

File not found: "ikitsuki_2.jpg" at page "Shinkansen Br.(connections between stringers and floorbeams in steel railway trusses)"[ź]

Fig.2 Crack location.

File not found: "ikitsuki_3.jpg" at page "Shinkansen Br.(connections between stringers and floorbeams in steel railway trusses)"[ź]

Fig.3 Crack detail.

Cause of fatigue cracks was as follows:

↑

6.Repair method applied †

Firstly,stop-holes(φ=20mm)were drilled at the crack tips(Fig.4).

File not found: "ikitsuki_4.jpg" at page "Shinkansen Br.(connections between stringers and floorbeams in steel railway trusses)"[ź]

Fig.4 Stop hole.

Secondaty,bolted splice plates was installed on the web plat of the diagonal member(Fig.5).

File not found: "ikitsuki_5.jpg" at page "Shinkansen Br.(connections between stringers and floorbeams in steel railway trusses)"[ź]

Fig.5 Bolted splice plates.

Finaly,steel bars were tightened to moderate stresses(Fig.6).

File not found: "ikitsuki_6.jpg" at page "Shinkansen Br.(connections between stringers and floorbeams in steel railway trusses)"[ź]

Fig.6 Moderate stresses by tightened steel bar.

The original diagonal member was replaced with new one in May 2010. (Fig.7).

File not found: "ikitsuki_7.jpg" at page "Shinkansen Br.(connections between stringers and floorbeams in steel railway trusses)"[ź]

Fig.7 Completion view.

↑

Reference †

Kaneko Tetsuya,A study on the Retrofits of Ikitsuki Bridge,Kyushu Gihou,vol.48,2011.01(In Japanese)

トップ   新規 一覧 単語検索 最終更新   ヘルプ   最終更新のRSS