Deep Foundation Specifications

[FndMech]

Hi, I'm a deep foundation drilling subcontractor. Methods and equipment for drilling deep foundations vary from contractor to contractor. When reviewing specifications for upcoming projects I find that whoever is writing the specifications really doesn't understand foundation drilling whatsoever. It makes it hard to provide a competitive bid when the specifications call for egregious and non-applicable methods, over designing of the materials. I would like to hear from anyone with a opinion on this matter. Thanks

 

[jayrod12]

The problem with that is furthered complicated in that when a specification is made that is either egregious and/or non-applicable no one discusses this with the designer. And even if they do tell the designer that the spec is out to lunch they don't come with any recommendations ready that would supply the finished product as spec'd.

Play nice with your designers and they'll play nice with you. Don't tell them the design is all wrong and they're stupid. Tell them that perhaps they aren't designing the most efficient or economical system and suggest alternatives with supporting evidence. If you can't prove to a designer that your alternative method is capable of providing the finished product as desired then why should they be willing to change methods.

Alternatively if you don't tell them something is wrong and all the companies just increase their bids to provide exactly what is spec'd then nothing will ever change either.

I don't even know if I just wrote a coherent point or not. It was more a word vomit than anything.

 

[jgailla]

I've seen it on several projects and in those cases it looked like the laziness or incompetence of the structural engineers involved.
A couple of times I gave up calling for clarification because the engineer clearly had no idea there was something wrong with their specs even when it was explained to them.
I've worked in design and there are a lot of engineers who don't pay attention to the specs. It's easy to do it because most contractors don't pay attention to the specs either.
The smarter contractors I've worked with put in carefully worded pre-bid questions and are able to shave some money off of their bid or (unfortunately for me) use the answer later in the project for a change order.

 

[cvg]

a good foundation designer is a combination geologist / geotech / structural engineer - hard to find

 

[JedClampett]

Well jgailla, here's a view from a lazy structural engineers side:
When we request Geotechnical Reports, we also ask the Geotechnical Engineer to provide a specification for their recommendations. Some do and some don't. But I guarantee you that when they do, I cut and paste it, word for stinking word, in our specifications. Sometimes the language is a bit permissive for specifications, so I have to change "should" to "shall.”
But many times, they don't provide anything. I either have to pull the information, phone call by phone call, from them or they just are not responsive. I had one recommend Vibro-Compaction to me for a project and when I asked for a specification, he said that would cost another $2000. Or telling me that 12 inch piles will carry 50 tons. How deep? What refusal? What size hammer?
I am much more worried about the foundation than anyone else on the project. My seal is on the drawings, not the Geotechnical Engineer's. If I make mistakes, it's due to a lack of direction, not laziness.

 

[miningman]

Well my sympathies on this one are with the OP. And its a problem that is not restricted to drilling foundations. As a contractor I've had to deal with specs that were obviously cut and pasted from O+G documents ( copper never-sieze shall NOT be used) which is a sensible spec on a O+G job but totally irrelevant to a dirty water pumping job, especially when the pump spec for the same job, specifically called for the use of copper never sieze.

And then there has been rock removal projects that deliberately spec either drill and blast or ripping. Why would the engineer spec this?? Identify the quantity to be removed and allow the contractor to decide what techniques to use and incorporate whatever penalties you want into the bid for overbreak... which is likely to some extent with either method.

Mind you Ive seen some sensible tunnelling projects where the engineer just specs the required finished dimensions, but demands a write up with the bid describing the equipment proposed, plus the proposed blasting techniques. Provided the engineer is experienced, this provides valuable info as to whether the bidders really are experienced or are a bunch of cowboys, whose services should be avoided at all costs. I wonder if this isn't at least partially the case in foundation drilling , because after all, none of us can see into the rock to know exactly what the conditions are.