I am looking for some advice on setting control for a multi-span bridge. There is almost 2 miles between each abutment. There is random traverse control set throughout the job that was set by others. We have a gps calibration that was perfromed a few months ago, from a permanent base station that was set on the roof of a building on site. We are hitting most of the control on the job within .05' or so.from one end to the other. I am just a little unclear on how to proceed as far setting all the control for the construction of the more than 50 piers on the job. We are not tieing in to any existing bridges, it is on a new alignment, and the abutments are all new as well. The bridge is to be constructed in stages, so the only thing I really have to tie in to is the stage line, to make sure we are not encroaching on the existing bridge during the first phase.
I was thinking of setting three GPS pairs, a pair at each end of the site, and one in the middle. Running a traverse through all of them, adjusting accordingly if needed, and then laying out all of the pier offsets from the main traverse. I have never done a bridge this long, so I want to cover all bases before proceeding.
Any thoughts or advice would be greatly appreciated.
I was thinking of setting three GPS pairs, a pair at each end of the site, and one in the middle. Running a traverse through all of them, adjusting accordingly if needed, and then laying out all of the pier offsets from the main traverse. I have never done a bridge this long, so I want to cover all bases before proceeding.
Any thoughts or advice would be greatly appreciated.
Replies
Hi Matt,
These days I am also doing bridge setting out so i am very interesting about this subject.but fortunately there are small ones not like your bridge.
As for as controls I don't see any errors your suggested method because those points are from primary control network.Length of the bridge doesn't matter as long as we are using primary control points.
Chamara