X-Wing
Civil/Environmental
- Sep 26, 2012
- 71
We were ask to inspect a bridge built in 1968 that will be replaced. It is a pony truss bridge, 37M bridge designed using HS20-44.
Upon inspection, we saw no or practically very few steel corrosion, no bent members, no visible rivet problems whatsoever. Bearing is still okay, abutments okay. No cracks on decks (as per inspection underneath the bridge) there is existing asphalt wearing course. One thing we noticed odd is that there is some "hump" just between the approach slab and the deck that may add force/impact on the bridge. Overloading also is a possible problem since the bridge is along a national road and many trucks are passing.
The twist is that back 2010, they constructed steel column supports with bearing pads at the middle floor beam of the bridge due to excessive deflections and vibrations back then (we aren't the one who evaluated the bridge back then). Now, we felt deck vibrations (which we think is normal for steel bridge), though we cannot assess the deflections and vibrations that much because of the presence of the middle support.
Serviceability problem? Or is there structural problem that may not be visible? Justifiable for replacement?
Thanks!
Very Truly Yours,
- andru18
Upon inspection, we saw no or practically very few steel corrosion, no bent members, no visible rivet problems whatsoever. Bearing is still okay, abutments okay. No cracks on decks (as per inspection underneath the bridge) there is existing asphalt wearing course. One thing we noticed odd is that there is some "hump" just between the approach slab and the deck that may add force/impact on the bridge. Overloading also is a possible problem since the bridge is along a national road and many trucks are passing.
The twist is that back 2010, they constructed steel column supports with bearing pads at the middle floor beam of the bridge due to excessive deflections and vibrations back then (we aren't the one who evaluated the bridge back then). Now, we felt deck vibrations (which we think is normal for steel bridge), though we cannot assess the deflections and vibrations that much because of the presence of the middle support.
Serviceability problem? Or is there structural problem that may not be visible? Justifiable for replacement?
Thanks!
Very Truly Yours,
- andru18
