M. R MAHERI - Department of Civil Engineering, Shiraz University, Iran
A. IMANIPUR - Department of Civil Engineering, Shiraz University, Iran

The jack arch slab has been used extensively in construction of ordinary and high-rise buildings in rural and urban areas in Iran. Due to the speed and ease in construction they are still widely used. The ordinary jack arch slab is considered by the engineering community to be a 'non-engineered' construction. This is because there are no sets of established procedures for its design and construction. In a number of previous studies, the author has addressed the problems associated with the traditional jack-arch slabs and has proposed some practical methods to enhance their static and seismic strength. The most effective method proposed is the conversion of the traditional one-way slab into a two-way system using transverse secondary steel beams to join the main load carrying-beams together. In this article, the results of experimental and theoretical studies carried out on a typical full-size model are presented. The results prove the favourable seismic response of the two-way slab and its advantages regarding cost, ease and speed of construction, compared to other engineered slabs.