Who designs cofferdams - EOR or Contractor?

[JennyNakamura]

Hi everyone,

When cofferdams or some other kind of stream flow diversion is required for bridge foundation retrofitting, are they designed by the engineer of record and shown on the contract drawings or are they designed by the Contractor (or his specialty engineer) like would be the case with scaffolding or falsework?

Thanks in advance...

 

[davidbeach]

Not a bridge engineer by any measure, but I've always been aghast at turning perfectly good, billable engineering work over to construction contractors.

 

[bridgebuster]

NYSDOT leaves it up to the contractor. The thought being that since it is a temporary structure a contractor may have materials on hand or is more confortable with a particular type of system.

 

[PEinc]

The contractor's engineer usually designs the cofferdam. That way, the cofferdam and bracing scheme will accommodate the contractor's construction methods.

http://www.PeirceEngineering.com

 

[cvg]

usually contractor designs. As the EOR, I usually give some minimum requirements or even a preliminary design to minimize the liability and to make sure each contractor is bidding a similar concept. contractor is then required to submit his final design for review by the EOR.

 

[gwynn]

I agree with PEinc. As someone who spends most of my time doing construction engineering, even if the EOR supplies a design for cofferdams or other temporary works, chances are the contractor will have someone else redesign it to suit their preferred construction methods/available equipment/available materials. So if you do design it, be prepared to spend time reviewing alternate concepts.

 

[PEinc]

When a contractor redesigns the cofferdam, in effect, the project owner is paying for two designs - one of which isn't needed.

http://www.PeirceEngineering.com