Rajat Avasthi and Durgesh.C. Rai
Rajat Avasthi, Doctoral Student, Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India, ravasthi@iitk.ac.in
Durgesh.C. Rai, Professor, Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India, dcrai@iitk.ac.in
ABSTRACT
Arch structures were the main form of construction before the advent of reinforced concrete. Arch structure resists load in compression if the thrust line lies inside the kern. The majority of old arch structures were constructed using stones and masonry material. In India, arch construction was widely used in bridges built in the pre-independence era. Capacity assessment of these old arch structures is needed due to deterioration over the years and increased load demands. Over the years, a number of methods have been developed to analyze masonry arch structures under different type of loads. Initially, elastic methods were developed using the thrust line concept, but later, the limit analysis methods have gained acceptance. Lower bound and upper bound approach was developed to calculate the collapse load for masonry arch structures. Majority of these studies were focused on the longitudinal behaviour of arches, i.e., treating the arch as a two-dimensional structure. Less attention has been paid to the three-dimensional behaviour of such masonry arch systems. Theories related to the dynamic load behaviour of masonry arch structures were also developed treating the whole system as SDOF system. Various experimental studies confirmed the dynamic behaviour of masonry arch system. The present study is focused on the state of the art of analysis of masonry arch structures and 3-D finite element modelling of these structures. 3-D micro-model of segmental circular masonry arch was developed in ABAQUS in which masonry bricks and mortar were kept as separate entities. Various components of the masonry arch system like the arch barrel, spandrel walls, piers, backfill soil were modelled and assembled using suitable interactions. Load carrying capacity of masonry arch was determined with the change in various factors like the thickness of ring, boundary conditions of spandrel walls, etc. The failure mode of the finite element model of masonry arch structures was found to be similar to previous experimental studies.
KEYWORDS: masonry arch, thrust line, lower and upper bound approach, mechanism method, micro-modelling, four hinge mechanism
