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The overturning resistance of structures base-isolated using laminated rubber bearings (LRBs) is crucial to the stability of the structure due to the poor tensile performance of LRBs. Pounding occurs between the structure and moat wall, which can result in a reduction of the overturning resistance of the structure. This study aims to investigate the overturning resistance of a structure base-isolated by LRBs considering pounding against the moat wall based on numerical simulations. The influence of the gap size, pounding stiffness, and the horizontal stiffness of the isolation storey on the overturning resistance of the isolated structure was evaluated through parameter studies. The results indicate that poundings between the structure and moat wall result in short but large pounding forces. Pounding forces would amplify acceleration, inter-storey drifts of the isolated structure, and significantly increase the risk of overturning of the isolated structure. Increasing the gap ratio can improve the seismic performance of the structure. Larger pounding stiffness leads to greater pounding forces generated by the structure, and the risk of overturning of the structure increases. The coefficient of overturning resistance initially decreases, and then increases, as the stiffness of the isolation storey increases.

Earthquakes have always been a menace to the lives and properties of human beings since the beginning of modern times. Several methods have been proposed since to mitigate the various types of seismic hazards, base isolation being one of them. The base-isolated structures being very effective for general far-fault earthquakes, are, however susceptible to high responses under near-fault ground motions; thus, several inerter-based supplementary damping devices have been proposed in this study to be applied alongside a highly nonlinear and effective unbonded fiber-reinforced elastomeric isolators (UFEI) system. The dampers are optimally designed and comparatively investigated with the isolation system for mitigation of a wide range of ground motions to the benchmark structure. Furthermore, two parametric studies were also carried out, which investigated the effect of the inertance-mass ratio and floor connectivity of the grounded damper on various responses of the isolator-damper-structure system. The parametric results are further used to suggest the best configuration and inertance-mass ratios for various dampers for effective seismic mitigation of the aforementioned base-isolated structure. The results show an effective reduction in seismic responses with the use of optimal inerter-based dampers in UFEI-isolated structures.

The attenuation of the maximum shear wave for strong ground displacements in large earthquakes (5.4 < M_w < 7.2) in California was studied from a seismological viewpoint. Smooth regression curves of attenuation were statistically fitted to measurements made personally on each seismogram. The curves were computed for two different geological classifications of the recording location (rock or soil), and two different fault mechanisms of the seismic source (strike-slip or reverse-fault). The sample consisted of eight strike-slip and four reverse-fault mechanism earthquakes with 237 soil and 92 rock peak ground displacement measurements.

The peak ground-motion displacements were measured from the S body-wave portion of the seismograms (frequencies between 0.2 and 1 Hz) after discrimination of the seismic wave types. The peak displacement from any surface wave train was not considered in this analysis. An attenuation distance H_slip was used as the distance from the recording station to the location on the fault plane of largest slip. Two sub-samples were formed consisting of the transverse (SH) and vertical (SV) measurements.

The set of ground-displacement attenuation curves predict greater amplitudes at sites classified as soil sites compared to rock sites, and for SH versus SV motion for both types of seismic source mechanisms.