Modelling Masonry Arch Bridges Containing Internal Spandrel Walls

Abstract

Masonry arch bridges continue to form a vital part of the transport networks of the UK and other countries around the world, where most masonry arch bridges have typically been in service for well over 100 years. To verify that they can safely carry modern traffic they need to be regularly assessed; however, assessment is not always straightforward, due to the wide range of geometrical configurations encountered and the many variables that influence structural behaviour. Specifically, whereas research in recent years has predominantly focused on the behaviour of arch bridges containing soil backfill, much less attention has been paid to bridges containing internal spandrel walls, which have different performance characteristics. In the present study the discontinuity layout optimization (DLO) numerical limit analysis technique is applied to bridges incorporating internal and/or external spandrel walls. DLO is an upper bound method capable of modelling both soil and masonry elements, enabling comparisons to be drawn between the behaviour of bridges containing soil fill and internal spandrels. After first validating numerical results against laboratory masonry arch bridge tests, the method is applied to a field bridge containing internal spandrel walls.