Load-Bearing Capacity of Masonry Arch Bridges Strengthened with Fibre Reinforced Polymer Composites

Abstract

This paper presents a new mechanism analysis method to calculate the ultimate load-bearing capacity of masonry arch bridges strengthened by externally bonding fibre reinforced polymer (FRP) composites on the intrados. The M– N relationship of a strengthened arch ring cross section is analysed and fully considered in the mechanism analysis. The Complex Method of nonlinear programming is used to perform a constrained minimisation of the load function to obtain the minimum collapse load and its corresponding hinge positions. This has advantages because the arch ring does not need division into many discrete blocks as in traditional mechanism analysis and the solution process is fully automatic. Some initial results are presented, which show that significant strength increases can be achieved by bonding a small amount of FRP composites to the intrados of masonry arch bridges.