Finite Element Modelling of Skew Slab with Edge Supports

Abstract

Newly designed bridges are often skew. This is due to space constraints in congested urban areas. Skew bridges allow a large variety of solutions in roadway alignments. This contributes to a small environmental impact for new road construction projects. It can also be needed due to geographical constraints such as mountainous terrains. However, the force flow in skew bridges is much more complicated than in right-angle bridges. Analytical calculations alone do not provide sufficient accuracy for structural design. Numerical analysis needs to be performed, in which a skew bridge can be modelled in several ways with different degrees of sophistication. The study reveals that the construction of simply supported skew slabs may be recommended only if the short diagonal of the slab is greater than its span otherwise it shows some uplifts at acute corners. The study deals with “Finite Element modelling of the RCC Skew slab with edge supports” with the help of ATENA. The ATENA is new FEM based software which helps in FEM modeling the RCC structure. The behavior of the simply supported skew slab under point load applied at the centre depends on the ratio of short diagonal to its span. Skew slabs with ratio of short diagonal to span less than unity show lifting of acute corners whereas slabs with ratio of short diagonal to span greater than unity do not. This is because the reactions act at the obtuse corner only when the ratio of short diagonal to its span less than unity and it is well within supports when ratio of short diagonal to span is greater than unity. In the present work FE modeling of the skew slab specimen with edge supports has been done and the results obtained are compared with experimental result of the skew slab without edge beam. By introducing edge supports in the skew slab the load carrying capacity has been almost increase by 2.5 times.