Precast Drawing Liability 1

[lutein]

We are a pure structural consulting firm.
Recently, we have these problems in precast shop drawings:

As usual, structural engineers do NOT check precast shop drawings, architects are supposed to review the dwgs. In this case, if the connections of precast to the structures and the precast load & location are not reviewed, it will come back and haunt us. But, if we review the drawings, and put some notes on the dwgs., the contractors and architects will assume we have reviewed them thouroughly for everything and we will be liable for this - BUT our contract do not normally include these responsiblity and we are not getting paid for this.

Questions:
From your experience, I would like to know if there is any NOTES we should put on the dwgs. so that we can limit our liability, or is there any notes that we should show in our specification? Please advise of how your firms have been handeling the precast shop dwgs? or how do you limit your liability but in the same time you have checked the precast?

p/s:In design phase, the desgined precast loads are assumed, we do not know the REAL load and location until we receive the shop dwgs. But at that time, the structures are up already.

 

[JedClampett]

We run into this kind of issue on occasion. I don't think there are any magic words which will make you "bulletproof" against any liability. If there's a legal problem, everyone will be on the hook, whether or not they reviewed the submittal or not.
I would require that all precast designs be stamped and sealed by the precast supplier's engineer. Then do as much review as your budget allows. The logical conclusion is that you don't have to review work already sealed by another engineer.
And keep your insurance premiums paid.

 

[ronster]

The architect usually checks the submittals and stamps them. I usually request a set from the architect to make sure that the connections are coordinated with the structure, that the stucture can support the loads from the connection, that the panels are designed for the proper wind and earthquake if rrequired)loads, and that they are sealed by a licensed professional engineer. I do not stamp these drawings as I do not design the panels. I will write a letter to my client stating what I did and if there are any problems or concerns.

 

[dlew]

lutein,

In Florida, the structural engineer must to show on the drawings the configuration, supports, anchors and connections of precast and prestressed concrete components.

The engineer may delegate the responsibility for the design of these components, in which case the engineer of the precasting plant shall submit signed and sealed calculations and drawings.

In any case, the structural engineer must reviewed the shop drawings as an indication that his intent has been understood.

I understand that other states may have other requirements.

Regards

AEF

 

[lutein]

Thanks for the professional input. Do your companies specs. the precast panel? If so, what are the important phrase must be there?

 

[jheidt2543]

Just my two cents:

If something goes wrong and there is a fight, in court or otherwise, everyone is drawn into the fray. So, why not make sure you have the opportunity to reveiw the shop drawings BEFORE fabrication! It is cheap insurance to spend the time reviewing the shop drawings and in my book it is the design engineer's responsibilty anyway. Just because the precaster hires a PE to do his component design it doesn't relieve the engineer of record from his overall responsibilty for the building's structural system. Another thing, letting the architect review the shop drawings for you is just BEGGING for trouble.

If everybody does their job, we all stay out of trouble (most of the time).

 

[dougantholz]

While not a "magic bullet" we have the following text on our stamp:

_ Conforms to the design concept
_ Conforms to the design concept, with revisions as shown
_ non-conforming; revise and resubmit

This submittal has been reviewed for general conformance with the design concept only and does not relieve the fabricator/vendor of responsibility for conformance with design drawings and specifications all of which have priority over this submittal.

We also have similar verbage in our general note on EVERY project (no matter how small) that states something that coordinates with the above.

In your instance, and base on my experience here in the midwest US, that contractors will complain when shop drawing review misses some items that must be later corrected; but that shop drawing review is only a cursory review and not a total project coordination. If they want total project QC, then we will write proposals for the extra money in order to spend the time, post design, to do QC.

 

[JedClampett]

My problem with trying to review these type submittals is that the suppliers like to use "black box" type, unformatted, hard to decipher calculations to develop their designs. When you try to recreate their work independently, there is usually some materials used that are unclear or proprietory and can't be found. Note that the joist suppliers are positively the worst at this. And I don't think it's unintentional.
So I put my trust in another registered professional, who is hopefully as competent as I am (not that that's any trick) and use his or her design. I do try to review what is presented clearly(end reactions, connection details, etc.) and leave it at that.

 

[BantrelStructural]

In theory as the engineer of record the structural consultant is on the hook for everything structural. With the usual fee structure and insane schedules it is almost a virtual impossibility to actually achieve full control of everything, requiring that we rely on other structural engineers to do their job properly. In the industrial field we often never get to see the field, with any inspection provided either by the client's own QA forces or another group with the EPCM contractor that we are either part of or partnered with.


Things that help in achieving the best outcome:

1. Good, and clear drawings and notes, including requiring that the sub-system is engineered and stamped appropriately, and in the correct jurisdiction (i.e. the jusidiction of final construction). Specifying hold points and preliminary mock-ups of unusual or tricky items can help here too.

2. Select reliable suppliers of sub-systems (not always in the control of the structural consultant), but there are better and worse players out there. Developing a dialog with their engineer, and perhaps even having early meetings with them to make sure that all are on the same wavelength certainly helps, rather than the usual post-submittal "surprise finds".

3. Do a reality check of their design. I had experience in the past with a joist supplier who was clearly way off base, where I ended up rejecting close to 90% of their joists for both design and fabrication deficiencies. They (and the contractor) tried to push this past me by erecting the rejected joists. As a result they were doing weld repairs and top chord reinforcing from scaffolding instead of on the ground. The joists in question were a "home brew" with double angle chords with single angle webs. Since it was virtually impossible to weld the roof deck to both top chord angles at each weld location, the unwelded (compression) chord angle would have had a kl/r greater than 200, so I insisted on welding spacers at all the mid panel points (all done from scaffolding!).

4. Keep the design as simple as possible. Many problems occur when the sub-system contractor cannot actually deliver what you want, and so the elements will not interact with your structure in the way that you assumed. If you are going to attempt something unusual (repeating item 2 here a little), try to convince the client to select the sub-system contractor early, and one that has on-staff engineers (not the guy who uses a moonlighting junior from one of your competitors), so that you can develop the design concept in concert with them, and work out the wrinkles early in the design cycle.

Hopefully you don't have too many instances like where an old colleague of mine remarked on returning from a site visit many years ago: "Any resemblance between what I designed and what they built is purely by coincidence".