ANALYSIS AND DESIGN OF SUSPENSION BRIDGE WITH REVERSE CABLE

Abstract

Suspension bridges have been constructed from ancient times using ropes and wooden planks but now the ropes are of steel wires and decks are of steel and concrete. In India suspension bridges have been used mainly in the hilly regions as foot bridges and for light vehicular traffic. However in the developed word these have been used for multilanes of heavy traffic. Only recently some bridges have been constructed in India for medium traffic and one bridge is under construction for Class-B loading. With the increasing traffic in the hilly regions, there is need to consider Class-A loading with two lanes. As compared to developed countries labour in India is cheap whereas l~ material and equipment are expensive. Due to these consideration the design in India differs from design in the developed word. In the present work analysis and design of a two lane suspension bridge for class-A loading has been considered. The bridge is provided with reverse cables and wind-guy cables, which are normally not provided in major bridges in the developed world. The effect of different main cable sag has been investigated. Towers fixed at base as well as hinged at base are considered. Piles and well foundations are considered for the abutments. Analysis is carried out using the STAAD PRO and detailed results for relevant load combination is presented in graphical form. A reasonably detailed design has also been carried out and the main material quantities have been presented in table form.