The Sombrio Bridge is a 122m long two-lane composite steel bridge with two spans of 40 and 82 meters. The superstructure is composed of four steel plate girders with a composite concrete deck. The erection scheme for the steel girders involves an innovative incremental launch using a counter-weight system and without the use of launch nose or a temporary tower in the longer span.
McElhanney’s bridge design and erection engineering group (formerly Infinity Engineering) is responsible for the detailed construction engineering of the steel superstructure designed to be erected through launching. McElhanney conducted a detailed 3D step-by-step staging analysis using LARSA 4D to support the complex erection of the Sombrio Bridge.