Steel Pier with Box section on The Metropokitan Expressway 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 Pier with Box section on The Metropokitan Expressway は削除されています。
Steel Pier with Box section on The Metropokitan Expressway の差分を削除

*Steel Pier with Box section on The Metropokitan Expressway [#ffb8071e]

**1.Field of application [#e1ace4ba]

>Steel pier at The Third line on The Metropokitan Expressway, Japan.&br;

**2.Circumstances of Repair [#k59c44a2]

>Fatigue cracks were found in welded joints ,which were the corner of the steel bridge pier,in 1997.

**3.Types of structure [#ke4ee51e]

>Front views of the steel piers are shown in [[Fig.1>#fig1]].
&br;
CENTER:&aname(fig1);&attachref(./pier_shutoko_1.jpg,20%);&br;
&br;
CENTER:Fig.1 Front of the steel piers
&br;

**4.Details of loading [#q6635827]
>Fluctuating loads due to highway live load. 

**5.Description of damage [#l8a61325]
>One of these fatigue cracks location and detail are shown in [[Fig.2>#fig2]].
&br; 
&br;
CENTER:&aname(fig2);&attachref(./pier_shutoko_2.jpg,20%);&br;
&br;
CENTER:Fig.2 One of these fatigue cracks location and detail
&br;
&br;

>Causes of fatigue cracks were as follows:
-Lack of fusion in the double bevel groove type welded joint which connected the transverse beam flange to the colum flange.
-Large cyclic stress due to live load.

**6.Repair method applied [#k9ac90d6]
>As the temporally-repair,bolted splice plates([[Fig.3>#fig3]],[[Fig.4>#fig4]]) were installed on the box webs of the connections.This repairing decreased the measured stress by about 50%,so that these piers could be used safely temporally.But it was needed to remove all the fatigue cracks as the final repair.
&br;
CENTER:&aname(fi3);&attachref(./pier_shutoko_3.jpg,20%);&br;
&br;
CENTER:Fig.3 Bolted splice plates
&br;
&br;
CENTER:&aname(fi4);&attachref(./pier_shutoko_4.jpg,40%);&br;
&br;
CENTER:Fig.4 Construction photograph of bolted splice plates
&br;

**Reference [#jfcdb670]
>Hisashi MORIKAWA,Tetsuhiro SHIMOZATO,Chitoshi MIKI and Atsushi ICHIKAWA,STUDY ON FATIGUE CRACKING IN STEEL BRIDGE PIERS WITH BOX SECTION AND TEMPORALLY REPAIRING,'''Journal of JSCE''',No.703/I-59,pp177-183,2002.4(In Japanese)
&br;