New tools for modelling soil-filled masonry arch bridges

This study is concerned with the development of new numerical and physical tools suitable for modelling soil-filled masonry arch bridges. Firstly, a novel modelling approach is presented which makes use of the Box2D rigid body physics engine, widely used in the computer games industry. A description of the simulation method implemented in Box2D is provided and it is shown that this tool is capable of accurately simulating disc and block interaction dynamics, and can successfully capture the critical state response of granular media. Four Box2D based computer programs, constituting a ‘virtual laboratory’, are presented and are shown to be capable of accurately simulating load tests to failure on both bare and soil-filled masonry arches. It is also demonstrated that the macro-scale properties of a virtual soil material, modelled as an assembly of randomly shaped polygons, are independent of the simulated scenario. Practical issues associated with the use of Box2D as a modelling tool are considered and advantages compared with the traditional distinct element method are discussed. Secondly, an innovative experimental facility developed by the author and suitable for testing medium-scale sand-filled masonry arch bridges is described. The test facility features a novel sand conveyance and pouring system which provides very good control over backfill properties and significantly speeds up the deposition process. Initial test results from the test facility are described and recommendations for future work are made.