The behaviour of brickwork arches subjected to cyclic loading
There are over 40,000 road bridges in the UK and most of them are over a hundred years old. These bridges were not designed to carry today's modern traffic and the everincreasing live loads especially with the introduction of 40 tonne lorries since January 1999. Moreover, in the case of multi-ring brickwork arches the penetration of rainwater and/or overloading with the passage of time breaks the adhesion between the rings leading to ring separation. The loss of continuum behaviour is accompanied by a significant drop in load carrying capacity. It is important that they continue to perform their functions. Sympathetic strengthening is preferred to demolition and replacement. A large amount of work has, in recent years, been devoted to the study of the behaviour of brickwork arch bridges subjected to monotonic loading. However, little is known about the behaviour under cyclic loading. The thesis reports the results of tests under cyclic loading applied at the quarter spans on six large-scale brickwork arch bridges of spans 3m and 5m. Some of them were constructed with damp sand between the brickwork rings, which simulate the defect of ring separation in real bridges. The tests were used to develop a better understanding about the behaviour and failure mechanisms of these arches subjected to cyclic loading. Additionally, the efficacy of surface strengthening to the structural performance of multi-ring brickwork arches was investigated. Both the ring separation and surface strengthening affects the behaviour of arches subjected to cyclic loading where the former reduces the carrying capacity and the latter increases the carrying capacity. The static failure loads of brickwork arches were predicted using four different methods: the mechanism method, Gilbert's 'RING' program, the elastic method and the FE method using ABAQUS software. It was found that the mechanism method and the 'RING' program were conservative in predicting the carrying capacity of the tested arches.