Beam Jacking
Beam Jacking
(OP)
I have a project involving some bearing replacements on an overpass over a very busy highway. Another engineer in our office suggested using a carrier beam like in the attached PDF. It would certainly help alleviate any problems with constructing falsework next to busy traffic by closing down a lane. We would be removing part of the deck as part of the rehabilitation anyway.
Does anyone have any experience using a system like this? Any lessons learned or something like that.
Thanks
Does anyone have any experience using a system like this? Any lessons learned or something like that.
Thanks





RE: Beam Jacking
I have heard of using hydraulic jacks just in front of each bearing pad location underneath hooked to a manifold so when the pump is turned on and pressure is applied all the jacks move at the same rate and pick up the entire side at once. One of my previous mentors used this method to replace bearings on a bridge 20 years ago.
This hydraulic jacking method is similar to the way they lift houses or structures to move them on a trailer from one location to the other.
RE: Beam Jacking
How close are you to traffic? Can you jack against the end diaphragms - you may have to reinforce them - or can you put a column in front? Your idea works but you may need a robust section to prevent buckling.
RE: Beam Jacking
It works nice since the footprint is a few feet plus barrier if needed. Can't really think of any pointers per se other than size the beam appropriately (or if the contractor has something in their yard) and brace it.
I have also made a saddle around the pier cap and jacked from there. Easiest to do with equal spans.
Also, EFFO makes a little support that bolts through and has a lot of capacity. It works well.
RE: Beam Jacking
I don't think I can fit a jack in front of the bearing, the gap between the bottom of the beam and the pier cap or seat is maybe 3.5". Do they make pancake jacks that slim?
I am worried about jacking against the diaphragms. They are concrete and "attached" to Type III and II beams. They are attached to the deck, but I would worry about damaging them or the deck.
BridgeEI when you say kicker angle, do you mean some kind of brace to prevent twisting or lateral buckling? How do you attach the end of the angle to the deck? I like you idea about a saddle, but I'm not sure it would work with a 60' Type III on one side and a 40' Type II on the other. Do you mean EFCO or EFFO?
RE: Beam Jacking
With those spans it would be hard to do a saddle. I haven't come across any low profile cylinders in the 3-4 inch range.
RE: Beam Jacking
Attached are a couple details from our office.
Enerpac makes some very low profile jacks. Can you get one thin enough to slide under the bottom beam flange and sit directly on the beam seat?
RE: Beam Jacking
This is pretty amazing. A 30 ton jack with a collapsed height of 2.31". There is about 3.5" between the seat and the bottom of the beam so that would work. Thanks!
http://www.enerpac.com/en-us/industrial-tools-impe...