this is not a question that anyone can answer without more details
Not to be blunt but... should someone without the skills to answer this question for themselves be involved in building a high-rise?
Lots of variables there but you will need to ensure your equipment is accurate. If you don't know how to check this yourself then take it to a technician. Your prism pole bubble should also be checked. I would suggest a short pole when possible.....less error. The building will have "grid lines" on the construction drawings. You will need to set up an offset for these gridlines on all sides of the building. Take much care in setting these points because they are the basis by which the first floor will be laid. The contractor will probably want you to lay on the anchor bolts for the steel beams or they may just ask for the center point of each column. These could normally be done radially if the building wasn't going to be very tall......If the building is tall and the contractor just wants the center points then definitely set up on each grid line offset and back sight the opposite side for your straight line. The contractor can make a templet for the bolts and square things up with string line. No matter what you do be careful with your staked out foresights......close range is best for angular accuracy. Like I said earlier....a short calibrated pole is best when possible too. Your project will depend on a accurate base grid from the beginning.
Thank you very much Mr. Fred Franklin. These are best fit to my queries. Very much appreciated. Very much useful for me. I just want to ask additional info, If we are going to establish an offset, is there an standard offset distance to be follow, let say 1 meter offset leftside in all of the grid-lines/ or we just make any offset we want depends on the site situation? TY.
which is most accurate method by manual chaining or total station method(coordinates)?
based on my observation, correct me if I'm wrong. 1 meter offset in all the grid-lines is enough. But be sure to established it accurately and in one side only to make it uniform and is not confusing. If you want it at left-side, then make your offset all left-side of the grid-lines...
Based on my experience, it depends to much on what kind of equipment you are using and the expertise you have. If a theodolite you have to set it in almost each grid to establish the position of the structural elements (OLD METHOD). If a Total Station (Manual or Robotic), you just need 2 points given by the surveyors, the distance of this points to the grid lines and ready to go. Additional docs such as the AutoCAD dwg's are very useful, and good staking software.
Hope it helps.
Thank you very much Mr. Ivan for your good ideas. I may ask again. Anybody have an ideas on how to RUN a CONTROL POINTS up to the NEXT LEVEL of STRUCTURE and so on..And what will be the PROCEDURE and the EQUIPMENT that we need to use? Hope youcan help Guyz...
as ivan said total station would be good to start your work, but make sure as building goes up, the tolerance for error increases. for that you have to transfer benchmarks to the upper level by digital laser device.
Hi Mr. Nizar,
Thanks for your ideas...
May I know what particular Digital Laser Device that we are going to use to transfer benchmarks to the upper level and what will be the procedure? Thanks a lot. Hope that you can help and and I appreciate it.
Offset 1m also good both theodolite and total station procedure but for easy and convenient procedure by coordinates gridline x and y N and E using TS.check first the traverse make it sure the benchmark first minimize the number of BM.
Be sure to guard your off set control well. Bring up in safety meeting their importance and get every one on board. On your off set column lines, lets call the left you speak of as west. You will also need to set up a series of perpendicular off set lines, lets call them south. If you don't have access to a digital laser measuring device to transfer BM's to the next levels, use a steel tape, we call a chain, and measure straight up and down. You can check your columns for plumb before pouring by setting up your calibrated transit, and look at the edge of your forms from bottom to top, from what we are calling south, then pick up and move to the left side we are calling west, and do the same thing. And quite a few more things you need to know!