The structural behaviour of thin shell masonry arch bridges

Abstract

Historical Arch Bridges in the Jiangsu Province of China were designed on uneven soil conditions, and hence they were optimised in such a way so as to allow settlement of the arch to occur without collapsing. This was possible because of the different approach taken by the Chinese bridge builders. This study deals with the understanding of the structural behaviour of the "Thin Shell Masonry Arch Bridges". These have a very small thickness-to-span ratio, when compared to their Western counterparts. This bridge type defies the minimum depth through which the Thrust line must pass. This work sums up all the literary sources available on Chinese Arch Bridges, their method of construction and the different types of structural elements utilised. This work refers to the "Theory of Mechanism Failure" by Jacques Heyman, which is adopted when understanding Masonry Structures. It also aims at understanding this peculiar arch type by referring to the Chinese literature, written by Theoretician Luo Ying. A testing rig was built, based on a simplification of the structural method of action, from a three dimensional approach to a two dimensional approach. A number of tests were then carried out, in order to understand whether the role of a "Diaphragm Wall" affects the thrust line of the arch. Three Different Arch Vaults, each with differing arch joints were constructed, using the same loading pattern, in order to understand the effect that the joint has on the structure. The behaviour of the arch under differential settlement of one abutment was also investigated. The outcome of this study will be used to understand how the thrust line is passing through such a thin shell.