So the following weekend will be preperation work and hopefully I can get a concrete pour during the following week - 2 weeks out. Then I have to wait at least 14, pref 28, days before I can start on the walls, but that gives me time to order them and the roofing stuff. Once all thats in place I can work on the inside through November and do some evenings so it'll go faster. I'll leave the external cladding and tidying as long as possible... maybe into next spring lol.
Well best laid plans etc....
The hole is still there, though its now doing a very poor impression of a swimming pool filled with porridge.
I was rushed with the digger and hadn't realised it was 100mm narrower than I needed and a little wasp waisted. Fortunately being relatively soft due to the water content I've managed to tidy up the edges and now its sides are parallel, vertical and the correct distance apart and I have dug the post holes for the 4 x 3 posts that will hold the retaining wall at the back. That'll be made of 4.2m long 225 x 50 (9 x 2) boards.
In the meantime I have finally completed the design of the steelwork needed in the concrete. Why do I need steelwork, isn't that a bit overkill I hear you ask? Well maybe if you dont care about cracks appearing in a couple of years time, but I want this to last 20years and still be stable and because its on a clay base and near a tree it has to cope with heave and shrinkage. The normal solution to that is to dig deep piling into the clay, about 4 - 5m deep or more and suspend the raft on top. Thats not an option for me, so the alternate is to build a concrete raft thats sufficiently strong to stand the lifting forces and also support itself if the clay shrinks from underneath a section of it.
The research into how to design such a raft has been interesting, there's surprisingly little info. A civil engineering graduate son of a friend said that it wasnt something they covered in his Uni course. But I have persevered and have now a design that meets the demands of BS8110 and I am confident it'll handle pretty much anything. It does come at a cost of £400-odd of extra steel but that was 1/2 the cost of the extra concrete needed in an alternate approach (not forgetting the need to dig the hole deeper as well).
It does make me wonder just how good a job the companies that estimated this work for me would have done. Yes they might have finished now, but the life-expectancy of the work would have been severely compromised. One wasnt using any steel at all ("not needed") and the other said "oh we'll throw some in if you want".
Here's a Sketchup of the steelwork... all 418kg of it!
Last edited by irving2008; 02-10-2012 at 09:19 PM.
OK, so having stared at my swimming pool/hole for a few days, I tried to work in it this weekend... after an hour of struggling in the porridge I gave up. I now have some inkling of how the soldiers in the trenches felt about the mud! So i need to empty the water from the hole so it can at least have an attempt at drying out. I need a pump that can handle dirty water, can pump close to the base (a lot can pump down to 4", well its not much deeper than that in places) and can shift around 2500litres in a reasonable time... suggestions? or can anyone lend me one for a couple of weeks?
Would it help digging a small sump hole in the middle from which to pump?
I'll see if we got a spare pump at work Irving, can't promise we have one spare but you never know. It'll be though but I have a transformer you could borrow also. If you had asked last week I could have dropped one round as I was working in Hendon this weekend.
Thanks Peter... Mocha has also offered, but its the logistics that always defeat these things... so the more offers the better - let me know if you have one...
Oh btw , heres the paddling pool of porridge... :(
hmmm... not sure where to send the water... the nearest drain/sewer is about 10m or so towards the camera... it cant go left or back as thats uphill... and right means flooding the back of the neighbours garden.... so drain/sewer it is... so I'll need some 10m or so of 1.5" or 2" flat hose or whatever the pump takes...
You don't need 2" for that little amount, some 1/2" hose on a little hippo pump would clear that in 30 mins and easily keep up with any incoming. A 2" pump would drain that lot in probably 2 minutes.
Small hippo would empty that easily and pump it 10mts to the drain. My small hippo can take a 40mm id hose. Empties my 2000 gallon fish pond in around 1 hour.
By Timo in forum Gantry/Router Machines & BuildingReplies: 6Last Post: 10-06-2014, 02:10 AM
By njh in forum Marketplace DiscussionReplies: 32Last Post: 11-10-2013, 06:35 PM
By Washout in forum Workshop & EquipmentReplies: 13Last Post: 26-12-2012, 09:22 PM
NEW MEMBER: CNC and other Machine Building BerlinBy Andikid in forum New Member IntroductionsReplies: 1Last Post: 07-10-2010, 10:30 PM