Chamberlain Br.
をテンプレートにして作成
[
トップ
] [
新規
|
一覧
|
単語検索
|
最終更新
|
ヘルプ
]
開始行:
*Chamberlain Br. [#a7d5a4c7]
**1.Field of application [#iad952e1]
>Chamberlain Bridge over the Missouri River near Chamberlain, South Dakota.
**2.Circumstances of repair [#o0131d7d]
>Fatigue cracks were found in the intermittent fillet weld of the vertical stiffener at the diaphragm locations in Sep. 1973 after 21 years of service. Further fatigue cracks were found in the girder web gaps of the girder-diaphragm connections near the girder compression flanges of the positive moment regions in 1973 after 21 years of service.
**3.Types of structure [#l999b01c]
>Span length of this bridge is 610.8m. Five spans truss bridge is connected to continuous plate girders approach. West approach is three spans continuous composite plate girder ([[Fig.1>#fig1]]) and east is two spans continuous plate girder. The plate girders were spaced at 2.75m and supported the reinforced concrete deck of 150mm thickness. The cross section of this plate girder bridge and view of internal diaphragms are shown in [[figure 2>#fig2]]. Transverse cross bracings as internal diaphragms were composed of angles, 126 by 126 by 8mm, and weld connected to the vertical connection stiffeners, 126 by 8mm. All the vertical stiffeners were only connected to the girder webs by the intermittent fillet welding.
&br;
CENTER:&aname(fig1);&attachref(Chambe1.gif);&br;
&br;
CENTER:Fig.1 Plan and elevation views of the approach spans.
&br;
&br;
CENTER:&aname(fig2);&attachref(Chambe2.gif);&br;
&br;
CENTER:Fig.2 Typical cross section.
&br;
**4.Details of loading [#w5867d56]
>Fluctuating loads due to vehicles live load.
**5.Description of damage [#vfe15f0c]
>Fatigue cracks were found in the girder web gaps of the girder-diaphragm connections near the girder compression flanges of the positive moment regions ([[Fig.3>#fig3]]).
>The 1976 inspection indicated that fatigue cracks were classified in three types as follows.
>1. Fatigue cracking along the girder web-flange weld.
>2. Fatigue cracking which occurred in the girder web at the top end of the intermittent fillet weld. The cracks propagated parallel to the girders ([[Fig.4>#fig4]]).
>3. Fatigue cracking which occurred in the intermittent fillet weld which attached the vertical connection stiffeners to the main girder webs. This type of the cracks showed the growth through the weld throat and the propagation along the weld toe of the girder web side ([[Fig.4>#fig4]]).
>Causes of fatigue cracks were as follows:
-Out-of-plane displacement of the girder web gaps of the girder-diaphragm connection which resulted from the relative vertical displacement between the girders.
-Discontinuity at the intermittent fillet weld roots of the vertical stiffener ([[Fig.5>#fig5]])
&br;
CENTER:&aname(fig3);&attachref(Chambe3.gif);&br;
&br;
CENTER:Fig.3 Crack occurred in the girder web gap.
&br;
&br;
CENTER:&aname(fig4);&attachref(Chambe4.gif);&br;
&br;
CENTER:Fig.4 Typical cracking pattern.
&br;
&br;
CENTER:&aname(fig5);&attachref(Chambe5.gif);&br;
&br;
CENTER:Fig.5 General view of the intermittent fillet weld.
&br;
**6.Repair method applied [#x4d34a6a]
>Retrofit holes were drilled at the crack tips in order to prevent the crack propagation. The top and bottom ends of the diaphragm connection stiffeners were connected to the girder top and bottom flanges by fillet welding of 75mm length and 8mm leg length.
&br;
終了行:
*Chamberlain Br. [#a7d5a4c7]
**1.Field of application [#iad952e1]
>Chamberlain Bridge over the Missouri River near Chamberlain, South Dakota.
**2.Circumstances of repair [#o0131d7d]
>Fatigue cracks were found in the intermittent fillet weld of the vertical stiffener at the diaphragm locations in Sep. 1973 after 21 years of service. Further fatigue cracks were found in the girder web gaps of the girder-diaphragm connections near the girder compression flanges of the positive moment regions in 1973 after 21 years of service.
**3.Types of structure [#l999b01c]
>Span length of this bridge is 610.8m. Five spans truss bridge is connected to continuous plate girders approach. West approach is three spans continuous composite plate girder ([[Fig.1>#fig1]]) and east is two spans continuous plate girder. The plate girders were spaced at 2.75m and supported the reinforced concrete deck of 150mm thickness. The cross section of this plate girder bridge and view of internal diaphragms are shown in [[figure 2>#fig2]]. Transverse cross bracings as internal diaphragms were composed of angles, 126 by 126 by 8mm, and weld connected to the vertical connection stiffeners, 126 by 8mm. All the vertical stiffeners were only connected to the girder webs by the intermittent fillet welding.
&br;
CENTER:&aname(fig1);&attachref(Chambe1.gif);&br;
&br;
CENTER:Fig.1 Plan and elevation views of the approach spans.
&br;
&br;
CENTER:&aname(fig2);&attachref(Chambe2.gif);&br;
&br;
CENTER:Fig.2 Typical cross section.
&br;
**4.Details of loading [#w5867d56]
>Fluctuating loads due to vehicles live load.
**5.Description of damage [#vfe15f0c]
>Fatigue cracks were found in the girder web gaps of the girder-diaphragm connections near the girder compression flanges of the positive moment regions ([[Fig.3>#fig3]]).
>The 1976 inspection indicated that fatigue cracks were classified in three types as follows.
>1. Fatigue cracking along the girder web-flange weld.
>2. Fatigue cracking which occurred in the girder web at the top end of the intermittent fillet weld. The cracks propagated parallel to the girders ([[Fig.4>#fig4]]).
>3. Fatigue cracking which occurred in the intermittent fillet weld which attached the vertical connection stiffeners to the main girder webs. This type of the cracks showed the growth through the weld throat and the propagation along the weld toe of the girder web side ([[Fig.4>#fig4]]).
>Causes of fatigue cracks were as follows:
-Out-of-plane displacement of the girder web gaps of the girder-diaphragm connection which resulted from the relative vertical displacement between the girders.
-Discontinuity at the intermittent fillet weld roots of the vertical stiffener ([[Fig.5>#fig5]])
&br;
CENTER:&aname(fig3);&attachref(Chambe3.gif);&br;
&br;
CENTER:Fig.3 Crack occurred in the girder web gap.
&br;
&br;
CENTER:&aname(fig4);&attachref(Chambe4.gif);&br;
&br;
CENTER:Fig.4 Typical cracking pattern.
&br;
&br;
CENTER:&aname(fig5);&attachref(Chambe5.gif);&br;
&br;
CENTER:Fig.5 General view of the intermittent fillet weld.
&br;
**6.Repair method applied [#x4d34a6a]
>Retrofit holes were drilled at the crack tips in order to prevent the crack propagation. The top and bottom ends of the diaphragm connection stiffeners were connected to the girder top and bottom flanges by fillet welding of 75mm length and 8mm leg length.
&br;
ページ名:
![[PukiWiki]](image/pukiwiki.png "[PukiWiki]")
