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# Setting out inclined columns

Hey guys I need some advice. I am doing setting out on a construction site and much of the stuff is just offsetting from grid lines. But now I need to setout an inclined column. Measurements provided on the drawing are for the top of column setting out at 8m at 6degrees inclination. The guys do not have an 8m box but a 6.4m box and will have to make 2 concrete pours, at 6.4m and then push it up to 8m at which the measurements on drawing should be obtained automatically. How do I calculate the dimensions at 6.4m.

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At least for me, you'll have to clarify the problem a little better.  A dwg would be best, but I'm not positive what you mean by "setting out 8m at 6 deg inclination"and even less sure what a 6.4m box looks like inrelation to a column pour or how 2 pours would make a difference (is that then a 12.8m box? squared? cubed?).

If an 8m (horizontal) offset is due to a 6 deg (off vertical) incline, then xsin6=8, so x (hypotenuse, or length of column along it's inclined face) = 76.534m and the vertical height of the column would be 76.534cos6 = 76.115m.

IDTH  (I Doubt This Helps)

The column is 8m, the box is a shutter for the concrete to pour the colmn, but they dont have a single box to pour the entire column in a single go. They have a box only 6.4m long, which will be the first pour of the column. Once this has set, the box will be moved up by 1.6m and the remaining column poured to complete an 8m column.

Hope this helps

Ah.

The best is to make a ratio of 8 to 6.4, which is 80%. So what ever the dimensions are for the 8m column, multiply but .8 to get the dimensions for a 6.4m box.

Give them grid reference offsets and a "smart level" with the digital display and tell them to check the forms & to have the forms as-built and checked before the pour. Time & money well spent BEFORE there is a PROBLEM
If you mean that you have the xy coordinates for the top of a column at 8m elevation, but this is at an angle of 96 or 84 degrees from the ground, then use some trig to calculate set out coordinates at 6.4m.

Or draw it in cad, flip it up on the correct grid line ucs and extend lines down at 6deg. Redraw one side of the column top at the 6.4m height position. Flip it back to top view then complete the column top or copy paste the original. As per Dave, i think a more detailed explanation would help though.

I must admit I tend to experiment with using AutoCAD in 3d rotate mode in order to get the various lines input properly. For starters the form-work will need an accurately slanted base using steel wedges to incline the form-work correctly. An Inclinometer mounted on a long straight box section of say aluminium might help here. Coupled with this you can do total station checks on key reference points on the formwork as an independent check (suggest using target stick-ons for this. Get a good measure up of the formwork done too to ensure you know what has been constructed.

From the CAD drawing you will easily be able to relate in 3d the various reference lines to the measurement points at any one time. Remember keep it simple and imagine you are trying to build the thing not simply be a surveyor measuring things. All the best

Hey guys, thanks a lot for the ideas. I used the ratios method to come up with the dimensions at 6.4m height and it came out well. 10mm on the y axis and 13 on the x axis when I was making for bolts on the top. It's within tolerance.

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