Light Live load Bridges over the River Nile in Sudan

Abstract

Bridge structures are vital for majority of Sudanese due to the fact that they live besides rivers, valleys and inside islands. Bridge construction is faced by the fact that it is extremely expensive. Cost of such structures is affected by live load which accordingly dictates the required dead Loads from both superstructure and substructure. In this analytical study a light live bridge load is derived making use of AASHTO principles. This practical live load is derived from data collected from sedan cars, bicycles, motorcycles, motorcycles rickshaws, auto rickshaws and pedestrian. The derivation yielded a design light live load composed of design lane load and design vehicle; to be applied simultaneously to this type of light bridges. The live loads are to be controlled at the bridge entrance. The derived loads are applied to different superstructures' systems, namely steel truss and composite steel plate girder. A single pier over two piles substructure system is chosen for such light loads. A case study bridge is designed over the River Nile. The results obtained showed tremendous savings in material and cost. Relative to normal highway bridges over the Nile, the steel truss bridge option reduces the cost by almost 60%.