Vehicle Barrier Wall Strengthening

[_csways]

We have been tasked with providing a strengthening design for a vehicle barrier wall that was previously cut to increase site lines. Both flexural and shear reinforcement were cut. Right now we are thinking about using either epoxied and bolted steel plates on each side or a channel to cap the cut area of the wall to provide the flexural and shear strengthening.

Can anyone recommend a reference for bonded and/or bolted steel plate strengthening?

 

[phamENG]

What exactly are you trying to strengthen? Max bending will be at the base of the wall and the capacity won't be affected by the cut top, and max shear will be at and below the point of impact - also below the cut top. I can see serious corrosion problems with the exposed steel that will be the end of that wall prematurely, but I'm not sure that the wall is especially weaker because of the cut top.

 

[_csways]

It is unclear if the (considerable) reinforcement that has been cut is just carry-over detailing or not. Thus, the desire to provide the same level of reinforcement. A section through the wall at this location is below.

 

[phamENG]

Hmmm...almost looks like they were trying detail the wall to help the beam in flexure. Doesn't feel quite right - but then I don't consider myself a concrete expert.

So apart from adding some continuity to sort of spread the load along the wall, I don't see that your 6 top bars doing anything especially meaningful for your impact resistance.

 

[EZBuilding]

The big issues here is how the cut reinforcement affect the shear and flexural capacity of your beam about it's longitudinal axis. I expect any impacts to it's capacity to function as a crash wall is secondary to those concerns.

Unless you share some demands and capacities, we will not be able to adequately assist you.

 

[SlideRuleEra]

We have been tasked with providing a strengthening design for a vehicle barrier wall that was previously cut...
Right now we are thinking about using either epoxied and bolted steel plates on each side or a channel to cap the cut area of the wall...

As a former bridge contractor we widened, repaired and rebuilt a number of structures. Steel plates and shapes are fine for temporary repairs, but it's preferable to have seamless permanent restoration. Reasons include safety, reduced maintenance, and appearance.

A permanent rebuild of this wall that appears to be straight-forward and practical is to use hydrodemolition to remove an appropriate upper part of the wall.
Stubs of existing #5 and #9 rebar can remain in place while hydrodemolition removes existing concrete from around them.
Replacement concrete, including necessary rebar spliced to the existing stubs, can be placed in the desired sloped shape.
Take steps to get a structural bond between existing concrete (lower part of the wall) and replacement concrete.
Also, I would install good-sized rebar dowels, using chemical anchors, along the centerline the wall to help tie new concrete to existing.

Here is my mark-up of the photo:

http://www.SlideRuleEra.net