This Content Originally Published by a land surveyor to Land Surveyors United Network
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
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.
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