Masonry structures are especially vulnerable to earthquakes. Previous studies have focused mostly on their mechanical characteristics, while masonry structures vary greatly in terms of structural and material properties. This thesis aims to present the post-crack dynamic behaviour of masonry structures on mechanism. Systematic studies, including pseudo-static experiments, shaking-table experiments and mathematical modelling, were carried out. In the pseudo-static experiments, scaled masonry walls with different geometric forms, bond types and corner connections were tested. The static-phase in-plane and out-of-plane damage mechanisms of masonry walls were classified. Their load factors and the influence of structural configurations were discussed. Experimental load factors are compared with theoretical ones derived from a limit-analysis procedure. The shaking-table experiments successfully captured the dynamic-phase response mechanisms. Three 3D dry masonry models were tested according to sinusoidal excitation based on either constant amplitudes or constant peak accelerations. Conclusions on the dynamic behaviour of the masonry structure were presented. The experimental basis for the theoretical model was presented. The influence of structural configuration and excitation figure were clarified. The critical factors were clarified as being the excitation frequency and L/H ratio of the façade. The consistent damage behaviour variations arising from these two factors were analyzed. A nonlinear dynamic mathematical model for the rocking of the masonry façade was developed, using a two-rigid-body model. The loads and frictional force on the top were included, with a horizontal excitation being applied. Assumptions of rigid ground, inelastic impact and point contact were applied. Six possible patterns were defined. The rocking, the impact and the possible transitions were formulated. Models in the shaking-table experiments were simulated to evaluate this model. Parametric studies were performed and future works were recommended.
|Date of Award||11 Jan 2017|
|Sponsors||Engineering and Physical Sciences Research Council|
|Supervisor||Dina D'Ayala (Supervisor)|