A Simplified Calculation Graphic Expression For Spandrel Filled Masonry Arch Bridges

For spandrel filled masonry arch bridges, combined effect between the ring and spandrel construction is significant. However, in existing bridge design codes, only the arch ring's load-carrying capacity is taken into account and the combined effect is totally ignored. Thus how to calculate their actual load-carrying capacity has become a problem needed urgently solution. Since a reasonable calculation graphic expression is the basis and is the key point as well. Thus, some research on the reasonable calculation graphic expression for spandrel filled masonry arch bridges was carried out, the main works are as follows:A simplified calculation graphic expression based on 2-D model with solid element was put forward. Since longitudinal behavior is primary . A plane model employing a 2-D solid element of Ansys was established, taking into account the nonlinearity of the arch-fill and contact between the ring and arch-fill. The good agreement between the model results and experimental data proved that plane model employing solid element is able to simulate the longitudinal behavior of spandrel filled masonry arch bridges.A simplified calculation graphic expression based on 2-D model based on beam element was put forward. Since much time and skill is still needed to build a 2-D solid model and the computational cost is high, 2-D model with solid element is not suitable for engineering application. Based on the analysis and comparison of common calculation graphic expressions, parameter analysis was carried out on following factors: shear deformation of the ring, rigidity of the abutment, equivalent calculation of spandrel construction, effect of bridge deck pavement, effect of dead load. Then a simplified calculation graphic expression based on beam element for spandrel filled masonry arch bridges was put forward. Factors effecting the mechanical behavior of spandrel filled masonry arch bridges are comprehensively counted in this simplified calculation graphic expression and the combined effect is reasonable considered as well. The results of the model employing this calculation graphic expression agree well with the experimental data, which proves that this simplified calculation graphic expression is capable to simulate the longitudinal behavior of spandrel filled masonry arch bridges.Safety checking computations was carried out for a new designed bridge and an existing bridge respectively, which show how this new calculation graphic expression is applied in engineering project.