Shaking table testing of groin vaults made by 3D printers

A novel experimental study of the dynamic and seismic response of a 2 m × 2 m in plan - 0.7 m in height groin vault model, involving 266 tests conducted on the shaking table of EQUALS laboratory, University of Bristol, UK, is reported. The experimental rig consists of blocks formed by a 3D-printed plastic skin to provide stiffness and strength, filled with mortar. Dry joints between the voussoirs are formed for ease of testing and vault reconstruction. No investigations of this kind and size have been attempted in the past. Two support boundary conditions involving four lateral confinement modes, leading to various vault configurations, were tested. White-noise, sinusoidal and earthquake motions were imposed in one horizontal direction, with progressively increasing amplitude and different frequencies, up to collapse. The model exhibited a strong non-linear behaviour, characterised by decreasing fundamental frequency and increasing damping with increasing table acceleration. Failure mechanisms and collapse accelerations were found to mainly depend on base restraint conditions.