This paper presents the results of static and dynamic tests on unreinforced brick masonry wall panels subject to out-of-plane loading. Fourteen wall panels were tested. The test program included static, free-vibration, and dynamic tests using harmonic support, impulse support, and earthquake support motion. The experimental results indicate that displacement, rather than inertia force amplitude, determines whether an unreinforced masonry wall will collapse during inertial (seismic) loading. An empirical force–displacement relationship is proposed that can be used for a substitute structure in a displacement-based method of analysis.

In a previous study published in this journal, the authors developed a comprehensive methodology for modelling the shear wave velocity profile in crustal rock, for purposes of seismic hazard assessment. The derived shear wave velocity profile was used to estimate the amplification and attenuation mechanisms in the transmission of seismic waves. The ability to conduct seismic hazard assessments in regions of low and moderate seismicity is greatly enhanced by this new modelling approach, given that developing a local attenuation model based on curve-fitting strong motion data is generally not feasible under such conditions. This paper reports a follow-up study conducted to evaluate the significance of near-surface attenuation in bedrock (as distinct from attenuation in unconsolidated soft soil sediments). The κ parameter is used to characterize the extent of this attenuation mechanism. Empirical correlations of κ with two forms of near-surface shear wave velocity parameter in crustal rock have been developed, employing information obtained from global sources in conjunction with that from local studies. The resulting development of two simple equations to predict median values of κ as functions of readily available shear wave velocity parameters represents the key outcome of this study. Applications of the proposed empirical approaches to determine κ have been provided, taking Hong Kong and Melbourne as case studies to illustrate different aspects of the proposed methodology. Consistency between the results obtained by the two recommended approaches has thereby been demonstrated.postprin

A stochastically based seismological model is described in this paper and used to generate synthetic accelerograms that are considered representative of intraplate earthquake events recorded on rock. The model, whilst well publicised in the seismological literature, is discussed and reviewed in this paper from an engineering perspective. The key factors influencing the frequency properties of the Fourier spectrum of the earthquake ground motion are presented and the differences observed between regions such as between eastern and western USA axe discussed. A procedure to generate representative artificial accelerograms from the Fourier spectrum is described. Average response spectra derived from these synthetic accelerograms are then compared with a selection of response spectra derived from recorded accelerograms to test and substantiate the model. The application of the seismological modelling approach to regions outside North America and the implications of the Displacement Based prinicples on the future development of seismological modelling have been addressed and discussed in the paper.