Belle Fourche River Br. のバックアップ(No.1)

• バックアップ一覧
• 差分 を表示
• 現在との差分 を表示
• ソース を表示
• Belle Fourche River Br. へ行く。
  • 1 (2013-09-30 (月) 14:54:49)

I-95 †

1.Field of application †

I-95 over Rappahannock River , Virginia.

2.Circumstances of repair †

Fatigue crack were found in the girder web in 1981 after approximately 20 years of service.

3.Types of structure †

The structure is composite construction with multiple longitudinal plate girders. The interior girder and interior of the fascia girder webs are strengthened with transverse stiffeners and lateral bracing.

The exterior of the fascia girder webs are strengthened with two continuous longitudinal stiffeners.

The longitudinal stiffeners are butt splice connected with vee groove welds and then fillet welded to the girder web(Fig1).The plate girders are thought to be fabricated from ASTM A373.

File not found: "i95_ht83.gif" at page "Belle Fourche River Br."[ź��]

Fig.1 Schematic of the exterior web face of fascia girders.

4.Details of loading †

Fluctuating loads due to vehicles live load.

5.Description of damage †

The crack occurred in the butt connection groove weld of a continuous tension-side longitudinal stiffener, continued through the web between the stiffener and bottom flanges, and penetrated the bottom flange.

Cause of fatigue crack was as follows:

• Separational discontinuities in the butt connection groove weld of the continuous tension longitudinal stiffener.

6.Repair method applied †

The fatigue cracked girder web and bottom tension flange were bolt spliced (Fig2).

File not found: "i95_ht84.gif" at page "Belle Fourche River Br."[ź��]

Fig.2 Bolt splice repair of fatigue cracked girder web and bottom flange.

The possibility existed for fatigue crack growth in the butt connection groove welds of other tension longitudinal stiffeners. Therefore, from the exterior of the fascia girder web, small hole was drilled through the girder web at the top of the fillet weld toe centered over the tension groove weld.

A 51mm diameter holes were trepanned from the interior of the fascia girder web centered on the longitudinal stiffener groove weld (Fig.3).The holes extended through the web into the longitudinal stiffener a maximum 3mm past the stiffener fillet weld toe.

File not found: "i95_ht85.gif" at page "Belle Fourche River Br."[ź��]

Fig.3 Retrofit of tension longitudinal stiffeners.

PukiWiki 1.5.0 Copyright © 2001-2006 PukiWiki Developers Team. License is GPL.
Based on "PukiWiki" 1.3 by yu-ji. Powered by PHP 5.6.38-1+ubuntu18.04.1+deb.sury.org+2. HTML convert time: 0.019 sec.