OT - Angling feet for my water tower?

[JasonPAtkins]

Hey all, this isn't a machining question, but is one that I think someone in the community will have a great idea for. I'm in the early phases of a construction project which will eventually be a base for my work here in West Africa, including my new shop.

The noodle scratcher of the day seems like it should have a simple answer, but I'm not as experienced in construction of this type.

Being totally off grid, the water supply will come from a tank up on a tower, filled by a solar pump, and gravity fed into the base's buildings. We're making that tower out of steel. I have some nice salvaged 5" round tubes to use as the main legs (20' long), which already have flanges welded to the ends with 8 bolt holes. We'll be pouring reinforced feet, embedded with threaded rod, to bolt the feet to, and then build the tower above it. The reason to do it that way rather than the much easier method of fabbing it in the shop and then standing it up is that I don't have a crane available.

None of this would be especially complicated, except that I'd like the legs to be angled a bit toward the center of the tank so that the footprint on the ground is wider than the weight, for added stability. If we were going to pour the legs straight into the concrete, I think I can envision a way to get them lined up using scaffolding and a plumb line, but since the pour will be setting the allthread and rebar, and then the tube will be stood up and bolted on later, and the rest of the tower reinforcing welded on in place, I don't have a great idea for a good way to get the allthread at the correct(ish) angles - it's going to lean on two axes. There is some play between the allthread and the holes in the tube flange, so there will be some adjustability once the concrete is set and we start to tighten the nuts, but I think the allthread needs to be pretty close, as a couple of mm of slop between the holes and allthread diameter doesn't translate into the 50cm that I need the 6m long tube to come off of vertical.




(Not shown is all of the cross bracing that will be included)

So, here's my best idea so far, someone please do better! My current idea is to make up a piece of plate that duplicates the tube's flange, but just has a stiff piece of 1" tube welded perpendicular to the face, only 4' long. If the rebar assembly is set in the concrete with that guide bolted square to the allthread, then a plumb can be hung from the top of that tube, and if the distance from the plumb to the bottom of the pipe is 1/5 of the distance I want the full 20' tube's head to lean in, on those two axes, then I should be golden. The guide needs to be stiff enough that it's not deflecting a lot but light enough that it's not going to pull the rebar/allthread assembly out of position during the pour. Controlling for the plumb's correct position should be easy, because I can run mason cord offset by that 1/5 amount of the offset, and then the plumb should just hang over the intersection of the two cords. I'm sure someone with exposure to commercial construction has a much better way of doing this - I think I'm proposing an ancient Egypt level solution.

Hit me!

 

[thermite]

I think I'm proposing an ancient Egypt level solution.

Hit me!

Lot older than Egypt. Only thing new is "steel".

.. "ancient Egyptian" or... Asian, yet-today, or ANY Navy "Sea Bee", Marine logistics, Army's "sappers", "pioneers", seige engine masters, or US Army Corp of Engineers, hasty construction, Theater of Operations, the last few hundred years do this shit all the time.

We were able to salvage a scrapped 25,000 gallon tanker trailer, put it atop a timber platform of re-purposed telecoms/power poles for the 'cold water'.

Similar deal with a timber platform and a re-purposed low-profile aviation unit fuel bladder provided the "hot" water off direct solar.

And 2600 men had a nice shower twice a day, Long Binh, 277th S&S Bn.

Just use wood and expertly done ROPE to hold all your s**t where your "instruments" show that it needs to be until yer 'crete has 7 days or better cure.

Remove it as you complete the steel, Don't waste any steel as ain't to be a permanent part of the package.

You need to have handy a US Army Corps of Engineers water-proof Field Manual we called the "Junior Woodchuck Handbook".

Chock full of all the useful s**t off sticks, rocks, cordage, raw timbers, salvaged battlefield JUNK, for "Egyptian era" tricks as ain't been beat yet for scarce-resource and lack of TIME solutions. Proper column loads, span calculations for beams and such are in there as well.

Your "local guys" will grok 'em right away, too! It's all basic and natural common-sense stuff.

It aint even "classified". Gummint printing Office sells it to the general public.

Might see if France sells THEIR one. USACE was founded by FRENCH Military Engineers, more than one. Your lads read French better than English, you have another training course? Safety, if nothing else.

 

[deltap]

A typical pipe fitter solution. Set allthread plumb in concrete. Bolt on flanged pipe. Heat band around pipe with large oxy-acetelene rosebud torch near the flange.Bend to desired position.

 

[DDoug]

double nuts flange where you want it, grout underneath when done.

 

[thermite]

A typical pipe fitter solution. Set allthread plumb in concrete. Bolt on flanged pipe. Heat band around pipe with large oxy-acetelene rosebud torch near the flange.Bend to desired position.

"A typical Machinashits's solution". Set it all plumb. Machine plates with large tab and HOLE. Machine matching clevis for the ends of the tubes. Bolt at whatever angle yah GET. So long as three or more legs? It ain't movin'.

Page Two:

Hairy-ears approach? Stringline will angle them close enough. Then yah grout any tilted flanges to match the 'crete.

Shit flexes. Load takes-up OK. Reinforcing is going to be welded on AS BUILT.. So it isn't really all that critical.

Preventing RUST, long-term, is what will be critical.

Ditto nasty biologicals taking up residence in the still water.

It's Africa. Tenacious and opportunistic life forms are everywhere.

 

[Rob F.]

To expand on what digger doug said earlier. Make your templates with a matching hole pattern as your pipes, use smaller holes(anchor bolt size) in the template to keep your anchor bolts centered in the holes of the real baseplate. Then you use a nut on both sides of the template to rigidly hold the anchor bolts to the template. Template should probably be at min 3/16" thick since anchor bolts wont hang plumb. Guessing the anchor bolts should be 3/4" or bigger and 18" long minimum. When you pur the concrete DO NOT pour to the bottom of the template, leave about 1 1/2 clearance under it to be able to access the nut on the bottom, this is to allow you to adjust the column for plumb later. After it is all installed and "plumbed" the 1 1/2 space under the flange is filled with non shrinking, high strength grout.

You have a pipe flange so I am guessing it is open in the center of the pipe? If so that should be solid, make you bolt templates a little thicker (3/8?) and leave enough anchor bolt above the template to add the pipe flange to it, with at least 1" thread above and 1" thread below the nuts.
Then you can remove the template and weld it to the pipe flange to fill the hole and give even distribution of the force.
This is how I set large structural columns for buildings and such.

I would figure the angle that the legs will be tilted in and cut a wood wedge at the proper angle so you can set a level form board around the pour, set a board across where the template will go, set your wedge on it with the template on top of that, screw or nail it all down to keep it from moving on pour day.

 

[DDoug]

everywhere[/B].

Neighbors using it as a bath tub.....

 

[Bill D]

Neighbors using it as a bath tub.....

Like this?
Bill D

 

[Tony Quiring]

This is done all the time with cell towers.

2 sets of base plates are made.

One is attached to the tower leg, plate is flat to ground so you do math there, or wait to weld until footings done.

Second set is used to set bolts.

Easy is to weld them into a frame to position them correct reletive to each other then place in position with anchors and pour footings.

Now tower legsbolt to footings and they are leveled by adjusting the nuts, one on bottom of plate and one on top.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[DDoug]

This is done all the time with cell towers.

Good thinking...the microwave radiation should make the tank "continuously sterilizing"
Plus...the monthly rent from the cell provider should help too..
.
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[Limy Sami]

Back in the day om such jobs (including building big tank stands for quickly filling crop sprayers) I found it best to draw out the various elevations (or sections there of) in full size - usually on the ground.

That way you get all your angles and true lengths etc etc etc set out in full size and easily taken off to be put on to the material,...………...plus you can lay all the parts out and make sure they fit the drawing.

As for erecting your tower, I'd probably hang a plumb line from the dead centre of the top platform then and measure from that.

 

[Bill D]

Back in the day om such jobs (including building big tank stands for quickly filling crop sprayers) I found it best to draw out the various elevations (or sections there of) in full size - usually on the ground.

That way you get all your angles and true lengths etc etc etc set out in full size and easily taken off to be put on to the material,...………...plus you can lay all the parts out and make sure they fit the drawing.

As for erecting your tower, I'd probably hang a plumb line from the dead centre of the top platform then and measure from that.

I remember decades ago reading about a Greek or Roman temple in Africa that they did this on the marble floor. Laid out arcs for column swell, golden rule roof etc. Greek empire collapsed before final construction which would have polished floor and removed all the doddles. City was abandoned so no one stopped by to steal building materials.
Bill D

 

[Garwood]

I poured the footings for my shop/crane about a year before I set the first post. I did just like Rob F said. Had .180 thick versions of my post flanges cut and set them 1.5" above the concrete. I used B7 allthread and double nutted the pieces 18" down in the footing to a skeletonized 3/8" thick flange welded to all the rebar.

The 1" flanges on my posts had 1" holes and I used 3/4" allthread. It all slipped together perfectly. The only bitch was getting to the bottom nuts with only 1.5" of room. I poured the post flanges into the finished floor and troweled mud under the flanges until it came out the other side and hit it quick with the vibrator.

If my studs had to be at an angle I think I would take my 3/16 thick alignment flanges and weld a light angle iron framework between them to set those flanges at the exact angle and relative position I wanted. Then level the framework, tie your rebar, pour, remove framework by cutting it away or you'd have to slot the holes to get it apart.

 

[mike44]

I helped a relative erect a tower for a windmill. The frame was PT 8x8 x 30'-0 high. I set 12"x12"x1/2" base plates with J anchors on the corners at each tower leg . Footings were 30" x 48" Sonotube . Base plates were suspended at the correct height and the concrete was poured.
U shaped 3/8" thick steel was thru bolted to the wood posts. The first section was lifted in place ,then welded to the base plates. The second and last section then lifted and lag bolted up with 3/8" x 7" x 8'-0 on all 4 sides.

 

[Bill D]

It would be easier to only slope the legs in one direction each. Make like a pup tent. About half the geometry that way. I assume the pre-welded flanges are at 90 degrees to the main pipe?.

Might make a good support to hold up some solar panels or a shade awning.
Bill D

 

[metalmagpie]

My suggestion is to don't reinvent the wheel. Go find a water tower and copy it.

 

[Flail]

Remember if all the bases are angled inwards, the bolts will be as well. As a result, the tower will not be able to drop down onto the holes in the plates unless the plate holes are slotted.

Having done something similar, I calculated the angle of the base plates, sawed the pipe ends with the horizontal band saw and welded the plates on. After the frame is assembled and laying on its ground, cut some plywood squares with holes to match the base plate holes. Temporarily bolt the plywood to the base plates, then connect the plywood squares with 2x4s remembering to tie opposite corners together so this structure is rigid. Take this newly made plywood “mold” of the tower base off, put your j-bolts into the plywood holes and set the mold in place with the j-bolts projecting down into the foundation holes. Level it up, place the concrete and voila! The j-bolts are set in concrete are all perfectly placed in relation to the holes in the frame which will drop straight down onto the bolts. Have a nut below and above the plate for final adjustment and when happy, apply non-shrink grout under the base plates.

 

[John Garner]

JasonPAtkins --

It might be far easier to think of the leg angles as simple angles in the planes defined by the diagonally-opposed leg pairs, rather than compound angles in adjacent-leg planes.

And, quite frankly, I think it might be worth the time and effort to cut and re-weld the leg flanges so that, when installed, the four lower flanges are in the same level plane and the upper flanges are in another level plane nearly twenty feet higher.

John