Precast girders geometrical elevation measurements

For bridge precast girders there are some elevation measurements that are an specific geometrical issue to achieve the final roadway profile while accommodating the girder camber and geometric effects of the roadway surface including super elevations, vertical curves, and horizontal curves. The main concepts involved are:

• Haunch: the distance between the top of a girder and the bottom of the roadway slab, it varies in depth along the length of the girder
• Minimum clearance: the minimum distance from the top of the girder to the bottom of the slab, also known as the fillet effect
• Camber: the vertical upward deflection from prestressing, creep, and shrinkage, to counteract the permanent loads

In more detail, for a tridimensional model, the profile effect, with the sum of the vertical curve effect and the horizontal curve effect as well as the consideration of the interaction of superelevation transitions with the girder orientation should be taken into account.