Shape imperfections of reinforced concrete shell roofs
B. Elferink, P. Eigenraam, P.C.J. Hoogenboom, J.G. Rots
The precise geometries of three reinforced concrete shell roofs have been measured with a laser scanner. The resulting point cloud has been modelled by NURBS surfaces. Two methods have been developed for determining the shape imperfections with lengths between 0.5 and 5.5 m. The largest observed imperfection amplitude is 80 mm with a length of 5 m. The imperfections are represented by a variance spectrum and a normal distribution. A formula for the characteristic imperfection amplitude and the partial safety factor are derived.
Key words: Shell structures, geometrical imperfections, laser scanner, normal distribution, characteristic imperfection, partial factors