A study of skewed continuous multilane concrete slab bridges -

Abstract

According to the USA Federal Highway Administration’s (FHWA) National Bridge Inventory data, a considerable number of these bridges are being recommended are being recommended for weight limiting posting, rehabilitation, or decommissioning and replacement. Reinforced concrete slab bridges may offer economic alternatives for short-span bridges in the USA and particularly in developing countries where cast-in-place concrete is common practice. The main advantage of cast-in-place concrete slab bridges is the ability to field adjustment of the roadway profile during construction. In the proposed research, the effect of skewness on continuous reinforced concrete slab bridges is investigated. The study will consider bridge decks with various angles of skewness and the live load distribution from truck loading on the solid slab will be determined. Two-equal-span continuous multi-lane bridges will be analyzed for a variety of span lengths and slab widths and depths and results reported along with the one-span bridges researched earlier. Loading will consist of AASHTO design trucks, positioned, laterally and longitudinally, to produce maximum moments in the slab. The analysis will be performed using the finite element method and a proper mesh model will be selected to account for the skewness of the bridge slab. Results will be compared with straight reference bridges and assessed with design procedures currently in use (AASHTO), and design recommendations for the main longitudinal reinforcement and for the distribution transverse reinforcement will be proposed. This research will assist bridge engineers in performing realistic design of skewed, one-span and two-equal-span, simply supported, multi-lane, reinforced concrete slab highway bridges as well as evaluate the load-carrying capacity of existing superstructure.