building a pit

[hturner12]

Has anyone made a pit? I have a 12x24 depth 3-6 feet inground pool that is no longer usable. My first thought was to fill in up to 6" and do a concrete slab to put the bird on. After thinking about it I think I can add the pit as well. I am looking for any information or feedback

[Lin]

I know that some have built pits with concrete.  I was wondering whether one could find something like a 6 x 15 or so dumpster and bury it to ground level to make an instant, removable pit.

[JohnEd]

I was in shop in San Diego that had an odd pit.  It was big as a pool and it had two steel girders embedded in it lengthwise.  There was 4 feet on either side of the "tracks".  The floor of the pit was about 5 feet deep and the tech used a short ladder to reach up in the vehicle from underneath.  This may benefit you as your pool has a drain installed that could be used as a "bilge" under a false metal grate floor.  Would collect all fluids and you could pump every few years.  Not subject to rain infiltration....right?  Should be electricity in the pool for lights that would come in handy for pit lights and small elect tools.  I don't think the pool shell would support much load beyond bare feet in water so girders like the ones I saw would be in order or dig thru the bottom of the pool to install foundation for vert supports.  This idea grows on me.

HTH,

John

[hturner12]

This may benefit you as your pool has a drain installed that could be used as a "bilge" under a false metal grate floor.

John
I think the previous owners of the house only bought closeout manufacturer seconds and any thing else that could be bought cheap. They did not think  to put a bottom drain in since there is a vinyl liner I am sure that I could convert the skimmer into drain . I agree the pool wall would not support the bus. I was thinking about block for the walls. Yes there is electricity (110v) at the pool. Either with or without the pit I will have the electric company set another meter dedicated to the bus and workshop .

[hturner12]

In doing more research I found   this site  http://tinyurl.com/clrkm4 it was written by a concrete contractor in CA.

[bottomacher]

The pit in the article is clearly not intended for a 35,000+ pound vehicle. Do yourself a favor and ask a local building inspector. Your @$# will depend on this structure...

[bottomacher]

Sorry- misprint. 25,000+ pound vehicle

[jackhartjr]

Well now, think about it...on another thread they talk about the weight added as part of the conversion.  35,000 or more is not out of the realm.
Jack
And do think about this...if it falls...
Please make sure that when the bus is over it it will stand up to the weight.
Every year or so we lose someone to their bus falling on them.

[hturner12]

Well now, think about it...on another thread they talk about the weight added as part of the conversion.  35,000 or more is not out of the realm.
Jack
And do think about this...if it falls...
Please make sure that when the bus is over it it will stand up to the weight.

Jack I have o plans of my wife getting the 300K.  The only way I will under it right no is to have the bags dumped. I have had a couple of suggestions about a container such a septic tank that could be a drop in the hole. I though about a shipping container but the width be about as wide as the bus. I like to get information as I can before taking on a project. A munch of mines is defiantly better than one. Plus some else on may be   considering the same type of project.
Every year or so we lose someone to their bus falling on them.

[hturner12]

Please make sure that when the bus is over it it will stand up to the weight.
Every year or so we lose someone to their bus falling on them.

Jack
That is the biggest concern I have no I do not plan on being the someone lost. While in the Air Force I worked heavy aircraft (B52, KC10A(DC10). Once you shortcut safety your name is on the some body lost list.

[bottomacher]

Some basic calculations are in order. If you have a 30000 lb. bus and four rear wheels, each tire having about 1.5 sq. ft. footprint, that means that the load on the footer of the pit will be about 5000 pounds per sq. ft under each wheel. The load is spread out by the wall IF the wall is solid, and that decreases the  concentrated load on the footer, but you still have a total of 30000 pounds to support. That's where your local inspector comes in- he will know the bearing capacity of your soil and frost line requirements. I personally pour 8" of concrete for the floor, with #5 rebar in both directions at 18", and extend it at least 4" beyond the perimeter of the walls. I add a gravity drain, not for water but for GASOLINE fumes that collect in the pit, since they are heavier than air. Diesel fumes are not as much of a problem, but I do it anyway. I then build a 12" block wall and pour it full of concrete up to the level of the bottom of the floor slab, and pour the floor over it, with rebar through the wall and bent into the floor (and the footer), covered all around by at least 2" of concrete in the slab. These are basic building practices, and will keep your insurance agent happy. Doing more than this is not necessary; doing less is a crap shoot. I'm sure some folks on this board will tell you that you can get away with less, and maybe that they have done it. But my way will get you a building inspection anywhere in the USA, last time I checked, and help you sleep better.

[jackhartjr]

And then there was the 80 foot pit at the truckstop in Lafayette, LA that over a period of years started to move inward from the pressure of the I assume unstable soil around it.  They welded 12 inch beams at roughly 10 foot spacing to the sides, it still kept moving in.  Finally they filled it in!
Jack

[circusboy90210]

Some basic calculations are in order. If you have a 30000 lb. bus and four rear wheels, each tire having about 1.5 sq. ft. footprint, that means that the load on the footer of the pit will be about 5000 pounds per sq. ft under each wheel. The load is spread out by the wall IF the wall is solid, and that decreases the  concentrated load on the footer, but you still have a total of 30000 pounds to support. That's where your local inspector comes in- he will know the bearing capacity of your soil and frost line requirements. I personally pour 8" of concrete for the floor, with #5 rebar in both directions at 18", and extend it at least 4" beyond the perimeter of the walls. I add a gravity drain, not for water but for GASOLINE fumes that collect in the pit, since they are heavier than air. Diesel fumes are not as much of a problem, but I do it anyway. I then build a 12" block wall and pour it full of concrete up to the level of the bottom of the floor slab, and pour the floor over it, with rebar through the wall and bent into the floor (and the footer), covered all around by at least 2" of concrete in the slab. These are basic building practices, and will keep your insurance agent happy. Doing more than this is not necessary; doing less is a crap shoot. I'm sure some folks on this board will tell you that you can get away with less, and maybe that they have done it. But my way will get you a building inspection anywhere in the USA, last time I checked, and help you sleep better.

don't worry you'lll get plenty of sleep if you build properly

[johns4104s]

HT,
I recently built a pit on a 55 ft x 14ft slab the pit measures 25 ft longx 40" wide x 4 ft deep. I have not used it much but I feel 4 ft is deep enough for me. The 25 ft allows me to pull the bus to work on the front then deep going to expose and work on the rear.I stabbed 2" conduit, one for water pump, one for electricity and one for air.
John

[luvrbus]

Concrete walls fail because of poor design the footing is the cause most of the time.Concrete walls will hold in any soil condition if designed right.I have poured 4 ft high walls that used a 6 ft wide spread footing.The loading docks at most of your Wal-Marts use this and these guys are cheap but the loading docks never fail.As for the blocks no way would I use that method for a pit.If I poured a pit 20 ft long it would be a least 8 inch walls with a spread footing and double mat of #6 or 7 re bar     good luck