Retrofitting

I have been assigned as the Structural Inspector for this particular project a construction of a 100mts diameter, dome shape, Coliseum. The main roof frames are made up of Open Web A36 Steel Roof Trusses ( we use varying ASTM A36 Tee section for the top and bottom chords and 50mm x 50mm x 6.35mm thk double angle as web members) having so as the supporting Truss Columns and resting on an existing reinforced concrete structure. The existing concrete structure are composed of the supporting columns 400mm x 800mm in dimension with beams having a dimension of 300mm x 500mm perpindicular to the 800mm lenght supporting the walkway, a 300mm x 600mm inclined beam perpindicular to the 600mm width of the column supporting the bleachers. The anchor bolts that will act as the support to the main roof trusses are existing, compose of 12 - 25mmdia x 1.00m A325 plain round bars without any bend or hooked at the embedded part ( as i found lately ). Doubts have been cast and querries had been raised particularly on the existing anchor bolts, whether it can withstand the forces of nature that the whole structure is subjected to. In response to foregoing circumstances, the Owner, the Contractor and the Consultants had agreed to undertake retrofitting works on the existing anchor bolts (the dimension of the base plate installed was 50mm thk x 400mm x 800mm having the same size as the column). We have already a scheme which we are to implement, but even so we are still open to suggestion from anyone who would like to extend us a help and coming up with a more comprehensive one. Thank you in advance.......