Shore-slab interaction in concrete buildings

Determining the load distribution during construction is one of the critical factors in assessing the structural safety during the construction of reinforced concrete structures. A simplified method was developed in 1963 for determining the construction loads imposed on slabs and formwork. Use of the simplified method assumes that the rigidity of the shores are infinite, and that the relative flexural stiffnesses of floors are all equal. However, it has been found that the results given by the simplified method generally underestimate the actual loads. The first part of this paper discusses a refined method capable of dealing with shore-slab interaction in framed structures without the assumptions just mentioned. Secondly, a comparative study of the predicted response for framed structures using the two methods is presented. Finally, the refined method is used to explore the influence of the sudden loss of selected shores.