Tamás Forgács¹, Vasilis Sarhosis², and Sándor Ádány³
1)  PhD student, Budapest University of Technology and Economics
H-1111 Budapest, Műegyetem rakpart 3.
e-mail: forgacs.tamas@epito.bme.hu
2)  Assistant Professor, School of Civil Engineering and Geosciences, Newcastle University
Newcastle upon Tnye, UK
e-mail: vasilis.sarhosis@newcastle.ac.uk
3)  Associate Professor, Budapest University of Technology and Economics
H-1111 Budapest, Műegyetem rakpart 3.
e-mail: adany.sandor@epito.bme.hu

Keywords: skew arch, discrete element model, arch-backfill interaction.

Abstract This paper investigates the mechanical behaviour of skew arch bridges taking into account the arch ring-backfill interaction. Simulations were performed with the three dimensional computational software 3DEC, based on the Discrete Element Method of analysis. Within 3DEC, each brick of the masonry skew arch was represented as a distinct block. Mortar joints were modelled as zero thickness interfaces which can open and close depending on the magnitude and direction of the stresses applied to them. The variables investigated were the angle of skew and the critical location of the live load along the span of the arch. At each skew arch, a full width vertical line load was applied incrementally until collapse. Failure modes and ultimate load carrying capacity values obtained. From the results analysis, it was found that for a skew masonry arch constructed using the false skew method, as the angle of skew increase, sliding between voussoirs in the arch increases and failure load decreases. Also, as the angle of skew increases, the loading position with the smallest ultimate load bearing capacity is from 1/8 span towards to the direction of the abutments.