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Piling: Preparing for the Quotes 1 -piling method


ToughButterCup

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'Forewarned is fore-armed' say some. Others 'do your due diligence'. Bottom line - do some background research. Here's mine. (With as many internet links links in as I can to help you with yours) If you can pick a hole I what I write, or see that I've missed something, I'd be so grateful if you could tell me.

Method

We already know that we have to pile. Does the SI report give a hint at which type of pile?

Have a look at this Phase 2 SI Report: Concrete Design page 12, point 7.4:   (SI = Soil Investigation)

Phase 2 S.I. Report - Bay Horse, Lancaster - G15002b.pdf

'... therefore the most practicable foundation type would be a bored pile solution [...] on this basis, concrete in contact with the ground may be designed to ACEC Class DS-1 AC1s of BRE Special Digest 1 - Concrete in Aggressive Ground...'

So now we know: they need to be concrete of a certain spec (Help!... no idea what the spec means)  and that the piles should be

'... sleeved in the upper portion to allow for ongoing settlement of the fill...' (Point 7.3 page 11).

 

What a difference a bit of research makes........ read on

 

There's no substitute for a good SE: one who engages with the customer's needs rather than merely doing the job (PM for details if you like). One line in their email to me suggesting we use a form of piling that is a good deal cheaper than traditional piling (Surefoot). And, in one sentence the SE had potentially saved his fee. They cost about half or less than traditional steel piles. Initial conversations with the company lead me to go and have a look at an installation. 

Here's what piles (if you can call them that) of that sortIMG_20160303_102453.jpg

look like.

 

So, after checking that there was no conflict of interest between the supplier and the SE,  we sent the detailed information to Surefoot. Disappointment. Our ground (see the SI report above) is too 'made-up' .

Hmm, back to square minus-a-few. 

 

Lesson learned? Keep looking. And that means hours on 'Tinternet. Hours of time apparently wasted. Hours of time which at the time that 'feel' wasted which could be spent doing a million other things . And then a post from  @Calvinmiddle  suggested I look at national piling contractors. And that lead me to Town and Country Vibro .

 

Instantly another set of unknowns and another research blizzard. Blizzard? Yes, that's how I feel.... I can see a few millimeters in front of my face, I can just about read my compass, I know where I'm going but there might be a crevasse one step in front.

 

What in heaven's name is a stone column? Can it really be as strong as a pile? Why the Heck does the SE specify a safety factor of 2.5(ish)

What is 'ground improvement'?

How much?

Why all the sales guff full of well-know management waffle? What does it actually mean? I really wish there was a Course in every Management Department in every British University which had a compulsory course called Cut_The_Shite_Out _Of_Sales_Speak.  It just gets in the way.

 

So, it's hours of YT videos.... bottom feed (my favourite) top feed (mehhhh) vibro (hmmmm) Gordon Bennett is it that quick?

A few phone calls later and I'm standing on a building site somewhere in deepest east Lancs with Dan. For reassurance you understand. And a chat with the  rig driver. Which lead to a quote. (Cheaper than Surefoot) Which lead to a site meeting at our place, which was well handled: there was a proper check list - whereas up to now a site meeting went something like this...

"Well mate y'll need 5 meter piles and we'll do the calcs for ya, 'kin SE's they're a waste of time and money"  A swift, polite Bye Bye.

Or (and this takes some believing)

"Your plot's the same as all the others round here: you'll need four meter piles , and I reckon the jobs going to cost you £20K" He had neither asked for nor seen any SI information - it was offered but he said "No need to bother son". It was the epithet 'son' which really got me. On arrival on site, he got out of the best kept top-line Mercedes I have seen for a long while.

I was almost rude in showing the contractor the door. Almost.

 

Piling design: TCV did that, and sent to our SE (Tanners) and that's where we are now.

 

Stone columns (ground improvement) is the method.

 

We need a piling mat: and that's another story.

 

 

 

 

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But now for us lesser mortals, you need to explain what "Stone columns (ground improvement)" actually is. (with a pretty diagram)
 

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Is piling ever combined with GSHP on domestic builds? Would seem a pity not to make use of a "hole(s)" if you could.....

Edited by Onoff
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Out of interest, can I ask how the Surefoot price compared to generic piling quotes? Looks to be a good system for some lightly loaded bases which I am dealing with.

 

Pilling mat is easy. Your SE should sort this out no problem, there is a design guide by the BRE. You are looking at a min 300mm of stone over the site however depending on the size of the rig. Is this included with the price?

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Never seen piling like that before but my god that looks cool. Must be some size of a rig with a lot of torque to do that kind of job.

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Here she is Declan. You a Led Zep fan too then?

zep.jpg

 

Blow me down it just had to be a German rig didn't it?

IMG_20160908_133422.jpg

 

and if I ask the driver very very nicely he might let me drive a pile or two. But then Declan, size isn't everything as many people have said to me. 

IMG_20160908_133236.jpg

 

I can just see @MrsRA wanting a go too now she's a part-time digger driver.

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Oh I would love a go on that!!! Must be close on 30t weight with all them attachments on the boom.

When it comes to diggers size is most def everything. 

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Blimey!, I didnt realsie there were so many different types of piling!  The site we looked at on the Graven Hill site would have needed pilings and they were quoting around 60k for the foundations.  Hope he lets you have a go - would be great fun.:D

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Neither did I.

The subject is very interesting indeed; piling has a long history too. And locally we don't have far to look for evidence.  On especially low tides at Lancaster, in the Lune river, you can see stumps of the piles used by the Romans when they stomped about up here.

Wonder if they were vibro(s)?

 

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On 11/15/2016 at 12:13, Daedalus said:

Out of interest, can I ask how the Surefoot price compared to generic piling quotes? Looks to be a good system for some lightly loaded bases which I am dealing with.

 

@Daedalus

£7,000 as opposed to way over double that

 

On 11/15/2016 at 12:13, Daedalus said:

Pilling mat is easy. Your SE should sort this out no problem, there is a design guide by the BRE. You are looking at a min 300mm of stone over the site however depending on the size of the rig. Is this included with the price?

 

No, it isn't in the price and when the next blog entry comes (soon - betcha can't wait!) be prepared to be shocked, stunned and not a little amazed.

 

Thanks to you I have downloaded the Design Guide. (Need a copy? I'll only charge double what it cost)

I deliberately went up to Darkest East Lancs to look at a piling mat, and realised I had been looking at them for years - all over the place.

 

Thanks again for the nudge.

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