transfer of control points on multi storey construction 1

[070909]

looking for advice on best or most accurate accurate way of transferring existing control points onto upper levels of buildings as construction proceeds .

 

[Drumchaser]

070909

We used a theodolite (set-up away from bldg)to transfer points to slab edge, then popped lines on floor and sprayed with clear spray paint to preserve as others pulled off for use.

 

[070909]

would you do this using a free station set up or is there another way?

 

[Drumchaser]

Free station....sorry, not sure what you mean.

I am assuming you have control points (ground level) that have been utilized to lay out the first floor.

I would use these known points to establish other relative points that can be transferred to the first slab, and used to layout walls, plumbing etc.

As the bldg. goes up, use the optical (90 deg.) site to transfer points up to edge of slab for establishment.

I have set up on slab (known pt.,above ground level)backsighted down to ground point and flopped to transfer line to other places on the slab.

Hope this helps.

 

[eea]

Drumchaser is correct and how we've typically done it. You could also run a level loop up the stair well, 3-wire for increased accuracy.