Bridge Rehabilitation

[newbuck]

Hi,

I am working on a project which deals with the rehabilitation of a RC bridge that was built in 1936. I work for a City and I am in the process of sending out a "Request for Proposal" to Structural Engineers to perform a Structural Analysis of the Bridge to determine the areas of Concerns. My Question is

What should be the output of the Structural Analysis? What should I ask the Structural Engineer to find out? What should be the output of the Study? What are the areas that I want to look at before I can work towards the rehabilitation Process. Can you understand what I am trying to say?

Any help will be greatly appreciated.

 

[ghghghgh]

Here are a few thoughts, I'm sure others will add their input:
You'll want a thorough analysis of the existing structure's capacity in relation to the loading it carries. They should be able to determine this through an inspection of the condition of the concrete.
Detailed description of areas in need of repair or reinforcement and an estimate of the costs, but not necessarily how it should be done. The contractor will most likely have experience with this (or make sure you let it to one that does).
Things to consider before rehab: Other alternatives i.e replace, abandon, lower load rating etc.

Other thougths anyone..

Good luck

 

[newbuck]

Thanks ghghghgh,

I do have on file a bridge inspection report that was done in october last year by Caltrans. However my thinking was that the inspection is only visual. Through the structural analysis I want the study to tell me what is going on within the structure.

In the bridge inspection report there is mention of spalling of concrete, exposed reinforcement, ravelling in the longitudinal joint between the original portion of the bridge built in 1936 and the portion of the bridge that was erected when the bridge was widened in 1963.

I was wanting the engineer to see the perfomance of the structure under various loads, creep,shrinkage and temperature effects, and find out the troubled areas in the structure.

Thanks for your reply. I appreciate it.

 

[bridgebuster]

What type of structure is it? A rigid frame? Regardless, you should obtain some cores. This would allow the engineer to analyze it with the actual compressive strength. Cores will also let you evaluate the concrete quality and items such as freeze-thaw durability (assuming you're in an area that has cold winters), air content, chloride content, etc.

As far as the analysis, require a load rating in accordance with AASHTO. When you say "troubled areas" that can mean two things: The weakest link in the structure or elements that exhibit physical distress, i.e., spalling, cracking, etc. An important factor to remember when evaluating analyzing/rating an existing structure is that you need a thorough inspection.t The analysis/rating needs to account for section loss.

BTW, if it's a rigid frame it might be cheaper in the long run to just replace it.