ARCH FILL INTERACTION IN MASONRY BRIDGES - AN EXPERIMENTAL STUDY

This paper presents some results of an experimental study of masonry arch performance. The study aimed to: (1) show that soil pressure varied with live load, but with a significant contribution from spandrel walls; and (2) remove the spandrel wall action by building arch rings in which the fill was contained in a lubricated box, so that the structure modelled in the analysis was essentially two- dimensional. A model bridge, similar to what might be built on site, was constructed in the laboratory, and assembled on the test floor. The bridge was semi-circular, with 4m span and horizontal skewback shelves, and its finished arch was 6m wide. Soil-structure interaction was recorded by 48 soil pressure cells. The following types of tests were performed: (1) applying a series of patch loads to the bare fill; (2) applying a series of patch loads to the fill with a 50mm layer of blacktop surfacing; and (3) applying a line load across the full width of the bridge to the surfacing. The results from the patch loads were much more interesting. The final line load test was destructive, and its pressure changes are charted. The results from the arch ring tests were incomplete at the time of writing. For the covering abstract see IRRD 869077.