bridge repair

[jnapier]

Hello,
I have read the posts on one member asking for help to replace the wood on his bridge. I need to repair my bridge and have other questions, I hope that someone can help me. OK here are some of my questions, but first my situation.
First let me explain what kinda bridge I have. It is a bridge that goes over a stream (40 feet long). It has earthen abutments on each end. Has two concrete pillars in the middle (12 feet high, 4 feet thick), and steel beams across the pillars with oak 4x6 decking. No railings.
I need to repair one of the concrete pillars, it is starting to wash away on the bottom from the action of the water when it floods. Right now it is only about 6 inches up from the base (the concrete is flaking away) and about 6 feet long. My thoughts were to drill into the concrete and put rebar into the drill holes, connect the rebar together to make a frame, I would also drill into the bedrock and place rebar into the rock, then construct a wood frame and pour concrete to make a base over the existing pillar. Has anyone done this before? Does anyone have any assistance they could help me with. I do not want to repair this poorly, but I cannot remove the bridge while I repair either.
[img]/forums/images/icons/frown.gif[/img]

[egon]

I'd strongly suggest an opinion or plan from a Civil Engineering licensed for your area who can do an on site investigation.

I realize this is really no answer but there are many unknowns involved.

Egon [img]/forums/images/icons/grin.gif[/img]

[jnapier]

Thanks Egon,
That sounds expensive. Do you know of a source to contact civil engineers in sw va. Please let me know if you do.

[egon]

I live a long ways from there.

Egon

[GaryM]

You might check with a local college and see if they know of anyone.

[egon]

Could you post more pictures of the area involved. This may give a little better understanding of your problem. What is the present used for?

Egon [img]/forums/images/icons/grin.gif[/img]

[LazyJ_Arabians]

I think the proper fix would be to get a new footing around and partially under the existing column with rebar extended into the additional column area to be created. I'd rethink drilling rebar into the existing support and approach the project more like putting a cast on a broken leg.

[jnapier]

Thanks everyone for the input so far. I know that repairing instead of replacing is not the best scenario. But I have limited resorces (money, equipment). I have a construction back ground, military, civilian. I use the bridge for access to my property as well as my neighbors use it to access one of thier large fields. The largest items that go over the bridge is my tractor (kubota 3850) the fuel truck (pickup with 55 gallon barrels), neighbors trucks and tractor, numerous cars. The pilings were built in 1936? the steel was added or replaced in 1970's? and the oak planking is new 3 years ago. The bridge is solid and the only issue is the one piling that is chipping away on the bottom by the water edge (due to water action when water is flooded). Look at the pictures for more clarity on the bridge, no picture on the damage though. I will take more pictures later. I am pretty sure that if I rebar drill into the pier and bedrock and form then pour high quality crete from the concrete company it will cure the problem. Just not sure. If any of you are engineers that might help with calculations of loads, cross loads, live loads etc. I think if I hire an engineer company (at least one in VA) it will cost me 15 thousand just to approve some plans. I could be wrong. But how did they do it in 1930's? Any help would be grateful.

JIM [img]/forums/images/icons/tongue.gif[/img]

[egon]

Finances are a problem for many of us; myself included.

From the picture posted any engineering firm type consultation and corrective action will be costly. The Firm must adhere to proper professional conduct.

I take it the piers sit on bedrock? If so your ideas sound good.

You may consider adding an exterior steel plate in the area where the erosion takes place.

You may also consider sandblasting/ chipping the surface of the piers to sound concrete and then covering with a layer of new concrete that is anchored by rebar drilled into the existing pier [ as per your thoughts ] and more rebar tied to the outside.

The areas on which the steel beams sit may also be taken in consideration for such treatment.

Wish I could help more but suspect you have a solution in hand that will work.

Egon [img]/forums/images/icons/grin.gif[/img]

[jnapier]

thanks again Egon,
I like your idea about the steel plate to slow the water action down. My only concern is the new concrete with rebar will not directly support the old pier. It should help with the movement back and forth, but maybe not down. I have been thinking about temping the bridge and removing the old pier and building a new one. Really tough though, that old bridge is heavy. In your opinon would new concrete on the outside with rebar going into or through the old pier help the old pier hold the steel up? I just don't want to start and then have to redue something.

JIM [img]/forums/images/icons/laugh.gif[/img]