| The Innerbelt Bridge (CUY-90-1524) carries Interstate Route 90 over the Cuyahoga River Valley in Cleveland, Ohio. The bridge was opened to traffic in 1959 and is a cantilevered steel deck truss with nine spans for a total length of 2,721 feet and a main span of 400 feet. Historically there have been several structural concerns with this particular bridge. Some of the concerns that have been noted are section loss due to corrosion, slope stability of the west bank, thermal strains due to inoperable expansion joints, and possible fatigue concerns due to out-of-plane vibrations in the web of a plate girder. The plate girder was added to widen the west end of the south side of the bridge.;The research presented here will discuss four investigations into the condition of the bridge. The first investigation consisted of instrumentation and live load testing of several members. The purpose of the investigations was to assess the condition of the members and to validate a finite element model of the bridge. An investigation into out-of-plane vibrations in the web of a plate girder was then conducted. This investigation's aim was to determine the cause of and severity of the vibrations. The third investigation consisted of monitoring the structure during repairs and modifications. Due to slope movement, the expansion joint located in Span 2 had "closed" and was inoperable. Several members were monitored during operations to "open" the expansion joint. The final investigation also involved structural monitoring. Several members were instrumented during the removal of the previously mentioned plate girder and the changes in the loads on the bridge were calculated. The results of this work were used to determine the condition and to aid in developing load ratings for the bridge. This work shows the importance of structural monitoring and investigation. |
