FINITE ELEMENT ANALYSIS OF FLAT ARCHES

The nation's bridge builders are turning their attention to flat arch construction as a cost effective and aesthetically pleasing solution for small span crossings. This paper describes the application of the LUSAS finite element analysis suite to flat arches with a span to rise ratio of ten. Load-displacement curves and collapse loads are presented. A parametric study involving: load position, arch and fill material properties, and relieving arch position has been completed. The effects of adding small span relieving arches above the extrados of the main span are investigated with a view to providing further capacity enhancement. Load-displacement curves and collapse loads are given for these modified arches. Small scale timber models with dry voussoir joints provide valuable experimental results for comparative purposes: at this stage the LUSAS model performs well. Further development to include more detailed fill-arch interaction modelling and spandrel effects is required.

• INTRODUCTION

• COMPARISON WITH MECHANISM METHOD

• LUSAS FEA MODEL

• COMPARISON WITH EXPERIMENTAL MODEL TESTS

• CONCLUSIONS

• REFERENCES