Trench Footing on Geopiers

[BubbaJ]

I'd like to start out by saying I am not one who is often at a lack for words, however, after receiving a recent email from an "unhappy" client, I will attribute my silence to some variation of shock.

Said "unhappy" client (U.C.) was commenting on a recent set of preliminary drawings which we presented to U.C. at a recent meeting and discussed many of the issues mention ed in the email. Apparently, I did a very poor job of "educating my client."

The building consists of precast double tees for roof and second floor, 32 foot tall insulated load bearing precast wall panels which I have proposed to sit on a 30" wide, 42" deep concrete trench foundation with longitudinal reinforcing in the bottom. The foundation is supported by 30" dia Geopiers at 6 feet O.C. due to low quality soils. The hold-down reinforcing cages at the Geopiers to resist the uplift from the high design winds are yet to be designed. The trench was proposed due to site constraints, proximity to property lines, existing structures, and multiple utilities.

Many of U.C.'s comments were concerning the lack of precast details which will be completed by the pre-selected precaster. So that can be easily addressed.

The knife in the back (or in the heart) were the comments regarding the proposed foundation. "I have spoken to several contractors that have been in the business for years because this goes against everything we have ever experienced and they also find the footings not acceptable at all." There is concern that the footings will "roll-over" in the ground. There is "tremendous weight" on "small" footings. And the list goes on. He wants the foundation to be a formed wall and wider footing (no he is not an engineer.) He is also demanding that an evaluation of my proposed foundation system be reviewed by another PE.

I have used this type of system on other projects with great success.

I am looking for opinions on an appropriate response to the email from U.C. This is a delicate situation as the Architect on the project is my business partner. How shall I handle this to at least keep their relationship intact and remain professional? I can think of a lot of response that will do neither.

I feel I am fighting a losing battle here. Please help!

 

[JedClampett]

First off, I'd like to say that in my exposure to contractors, they never have seen anything that looks like my current design/foundation/roof system/door details/urinal piping etc., etc., etc..
If you don't have a Geotechnical Engineer on board, I'd definitely hire one. They can review your existing design, suggest an alternative and generally cover your backside. This could be your review by another P.E. If they concur with your design, I think you've done a pretty good job.
IMHO, 30 inch Geopiers at 6'-0" sound pretty substantial, but I don't know your loads, soil conditions or other inputs.

 

[DonPhillips]

I would not continue the conversation in e-mail. I would call UC and schedule a face to face with the client - after I bring on someone to support the design - to specifically go over the specific concerns with the contractor. Sounds like someone has the client's ear and keeping the client's confidence is very important. If the client and contractor want to discuss the design calculations, perhaps that is what is needed to ensure their confidence.


Don Phillips

http://worthingtonengineering.com

 

[jike]

If your design will be subject to review, make sure that you can prove by calculation that all of their concerns are unfounded. Then if you can prove that your design is more economical than the proposed formed wall and footing, you generally should absolved......but.....

There, however, is still a risk that their pride and ego, may be such that they are unwilling to accept any calculation or reasonable explanation of your design even by an independent PE. In this case, it might be wisest to back off and change your design.

Take the high road. Keep it professional.

 

[BubbaJ]

I am going to contact the Geotech Engineer for the project and Geopier rep tomorrow, assuming we all still have electricity then. Hopefully they will have some input also.

While the loads are high in comparison to say, stick built construction, they are not outrageous by any means. However, the weight of the panels themselves has been huge topic of conversation. U.C. seems to be obsessed with how it will be possible to set such heavy panels. (?) As I have told U.C. on many occassions, larger buildings than his have been constructed.

I have tried the "if you want it bigger/more rebar/etc. you can have it" approach, it did not work. I told him that at the last meeting. He even asked how I figured out how much rebar was needed (like I just pulled it out of the air.) Now in the email he said we shouldn't just put more rebar in just because he wants it, but in the next sentence he tells me the footing needs to be wider. (Huh?)

Ok, so say I get people to back me up, which shouldn't be a problem, then what? Will he see it as us ganging up on him? Do I just move forward like this didn't happen? If he sticks with a conventional formed foundation wall, how do I accept that without it being an admission of wrong doing?

I believe all this doubt stems from a issues on a previous project we worked on for U.C. There were a few problems during construction which the contractor blamed on me, even when one of his guys flattened some anchor bolts with a loader and also that I delayed construction because I wouldn't let them backfill at 14 foot tall basement wall without the floor framing in place. Because I was very young at the time, he believed the contractor and my employer at the time believed the client was always right and let him walk all over me. I think he still harbors feelings that I cannot possibly know what I am doing, even though he proclaims that he doesn't hold grudes, HA!

I have to take the high road, my engineering business depends on it. U.C. is a prominent player in his community, he could do a lot of damage, although I fear he has already done so.

 

[JEmH]

I realize that PE's aren't generally proponents of the supernatural, but I find that the mere act of printing off a few resumes the night before magically makes a client meeting go swimmingly.

But seriously, I would make sure that the Geotech in on board with the design, and get another structural guy to at least gut check the design. The thing I would be 100% diligent on is making sure that your Architect partner knows what is going on with the client so that the company is showing a united front. The thing I hate the most is having someone who is supposed to be on my team inadvertantly (or purposefully) throw me under the bus.