Steel bridge with hangers and pinned connections の変更点

追加された行はこの色です。
削除された行はこの色です。
Steel bridge with hangers and pinned connections へ行く。
Steel bridge with hangers and pinned connections の差分を削除
*Steel bridge with hangers and pinned connections : Replacement [#ed3f250c]

**1.Outline [#e8dc503c]

>Fatigue cracking and failure cases were reported in the steel bridges which contained pin-and-hanger assemblies, U.S.A. 

>Table 1 illustrate parts of various localized failures of hanger and pinned connections.

CENTER:Table 1 The outline of the localized failure cases in U.S.A.
&br;

CENTER:
|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Bridge|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Structure|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Failure time|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Years of service|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Failure location|
|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Point Pleasant br.|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Suspension br.|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Des. 15.1967|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:39|BGCOLOR(#FFFFFF):COLOR(#000000):LEFT:Head of a upper suspension eyebar|
|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Route 157 br.|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Suspended plate girder br.|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Oct. 23.1978|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:33|BGCOLOR(#FFFFFF):COLOR(#000000):LEFT:Hanger shanks at the thickness transition radius|
|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Route I-95,Maryland|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:deck truss br.|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:1985|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:20|BGCOLOR(#FFFFFF):COLOR(#000000):LEFT:Rivet holes of the hangers located 2 ft below a pin|
|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Route I-95,Conneticut|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Suspended plate girder br.|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Jun. 28.1983|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:25|BGCOLOR(#FFFFFF):COLOR(#000000):LEFT:Bearing surfaces of the pin-and-hanger assemblies|
|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:Ninth Street br.|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:self-anchored Suspension br.|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:cracking prior to 1985|BGCOLOR(#FFFFFF):COLOR(#000000):CENTER:59|BGCOLOR(#FFFFFF):COLOR(#000000):LEFT:Anchorage eyebars at a corrosion notch|
&br;

**2.Structure and Damage [#b4940ee1]

>The collapse accident of the Point Pleasant bridge in West Virginia have been well known. The Point Pleasant Bridge is an eyebar chain suspension bridge ([[Fig.1>#fig1]],[[2>#fig2]],[[3:cross section>#fig3]]). Fracture occurred through the head of a suspension eyebar ([[Fig.4:typical eyebar joint>#fig4]],[[5:fracture eyebar>#fig5]]). Therefore, the collapse of this bridge resulted from brittle fracture of the eyebar due to stress corrosion.  

>On the other hand, Illinois Route 157 is composed of multiple spans with multiple longitudinal girders ([[Fig.6>#fig6]]). Two of the spans are supported by pin-and-hanger assemblies on one end of the girders ([[Fig.7>#fig7]]). 

>Fracture occurred through several hanger shanks at the thickness transition radius ([[Fig.8>#fig8]]). 

>These structures indicated that the anchorage eyebar and the pin and hanger assemblies were generally subjected to bending from joint fixity. 

&br;
CENTER:&aname(fig1);&attachref(Hanger8.jpg);&br;
&br;

&br;
CENTER:&aname(fig2);&attachref(Hanger9.jpg);&br;
CENTER:Fig.2 Point Pleasant Bridge (“Collapse”1968). 
&br;

&br;
CENTER:&aname(fig3);&attachref(Hanger10.gif);&br;
&br;

&br;
CENTER:&aname(fig4);&attachref(Hanger11.gif);&br;
&br;

&br;
CENTER:&aname(fig5);&attachref(Hanger12.gif);&br;
&br;

&br;
CENTER:&aname(fig6);&attachref(Hanger13.gif);&br;
CENTER:Fig.6 Illinois Route 157.
&br;

&br;
CENTER:&aname(fig7);&attachref(Hanger14.jpg);&br;
CENTER:Fig.7 Typical hanger joint.
&br;

&br;
CENTER:&aname(fig8);&attachref(Hanger15.jpg);&br;
CENTER:Fig.8 Cracked hanger.
&br;

**3.Repair method applied [#k2968ec0]

>In case of localized failures of hanger and pinned connections, repair is generally recommended by replacing of damaged members. In Route 157 bridge, I-95 in Connecticut (for remaining connections) and Ninth street bridge, repair was performed by replacement. 

>In case of the cause such as pin fixity, repair was generally performed by lubricating or cleaning up the pins.
&br;
&br;