Strengthening and Widening of Crossbeamless Slab-Ribbed Bridge Spans with an Overlay Slab

Prefabricated crossbeamless slab-ribbed span structures are common in construction practice. They were designed in the Standard Design Issue 56D (supplement). This design has a number of advantages and disadvantages. Due to the advantages, such span structures have been successfully used in Ukrainian construction for many years. However, at present, most of them do not provide sufficient bridge deck dimensions and load capacity, so they need to be strengthened and rehabilitated in accordance with modern requirements. The method of reconstruction of such bridges using an overlay slab with cantilevers allows for both widening and reliable strengthening of the span structure. A monolithic overlay slab with cantilevers is installed on top of the existing girders. For reliable joint work, the slab and girders are connected by flexible anchors. A special feature of this reconstruction method is also a change in the static scheme of the span structure. The girder sectional static scheme becomes a beam- or frame non-sectional scheme with rigid bearing nodes. The article describes the design solutions and technical condition of existing crossbeamless bridge spans built in accordance with the standard design of issue 56D, as well as effective solutions for their reconstruction and the results of in-situ tests of such bridges before and after reconstruction.