ANALYSIS OF LIGHT WEIGHT CABLE STAYED PEDESTRIAN BRIDGE

Abstract

In general, a suspension bridge is more effective at carrying dead load than a cable-stayed bridge is at carrying live load. A cable stayed bridge's most cost-effective span length is between 100 and 350 metre, while some designers have increased this range to 800 meter. There are a few issues with the use of conventional materials in the design of cable stayed bridge like due to constantly increasing aggressiveness of the environment durability of reinforced concrete slabs is less than the durability of the main girders or other basic elements of bridges, self-weight of deck made up of concrete increases with the increase in span of bridge, corrosion of reinforcement and cables, sagging of steel cables under their self-weight and several problems during their maintenance works. As design objectives for lightweight materials, the cables should have maximum stiffness and light weight, ease in corrosion protection, fatigue resistance, high and stable Young’s modulus, compact cross-section, high tensile strength, easy handling and installation, and low in initial and maintenance cost. FRP has the ability to span wider because it is a highly strong and lightweight material., concrete deck slab which are prefabricated and made of lightweight concrete (LWC) and reinforced with Glass Fibre Reinforced Polymer (GFRP) bars are used as substitute to RCC slabs, pylons can be manufactured from filament wound glass fibre reinforced plastics (GFRP). In this dissertation work a Cable stayed bridge is analyzed for static and dynamic load due to pedestrian moving on that, this bridge is modeled with the help of MIDAS CIVIL software in this model deck is made up of web core section with GFRP as material. These configurations dramatically reduce the weight of deck and also reduce the periodic maintenance cost of deck. In the present study, initially, the problem of cable stayed pedestrian bridge is analyzed with help of MIDAS CIVIL for the given loading and the results like mode shape of bridge is compared with the work done by previous researchers. In all cases the results obtained by the present FE model compared very well with the EUROCODE limits for pedestrian loading condition. A parametric study has been carried out in which a model of cable stayed bridge is made with GFRP and Aramid fiber as material and perform analysis of same for static and pedestrian loading. Different models were created with change in material properties of different element of bridge and analyze these model for same loading keeping in view the design requirements for their feasibility. The effect of change in cable spacing is also analyze for different criterion's like displacement, acceleration and bending moment in deck.