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Many seismic studies treat a vehicle-bridge coupled system as a bridge-TMD (tuned-mass damper) system, and, unsurprisingly, have found that the vehicle usually reduces the seismic response of the bridge. The current study challenges this notion by looking deeper into how a vehicle in motion influences the seismic performance of the bridge that it traverses. Specifically, the analysis explores the underlying physical mechanisms of vehicle-bridge interaction (VBI) and TMD, identifies the dominant terms in each system, and highlights both their similarities and differences. In this context, the study compares via pertinent numerical simulations the effect of a moving vehicle versus a stationary vehicle on the bridge, under a set of natural earthquake records along solely the vertical direction. The study also shows how the vehicle's speed and timing (i.e., time difference between a vehicle's entry to the bridge and the earthquake's occurrence) influence the seismic response of the bridge. [ABSTRACT FROM AUTHOR]

Structural reliability methods are employed in this paper for nationwide probabilistic seismic hazard analysis of Iran and in-depth seismic hazard and hazard sensitivity analysis of Downtown Tehran. The companion paper proposes two analysis approaches based on reliability methods and presents the technical framework for such analyses. The first approach was based on Monte Carlo sampling reliability analysis, which is employed here to conduct hazard analysis at a grid comprising 3695 sites throughout Iran. The results are used to produce nationwide hazard maps for the peak ground acceleration, spectral acceleration, and cumulative absolute velocity. The other analysis approach employs the first- and second-order reliability methods and importance sampling and is applied to the seismic hazard analysis of Downtown Tehran. This analysis identifies the seismic sources that are most influential on the seismicity of Tehran. In addition, reliability sensitivity and importance measures are employed to identify the most influential sources of uncertainty on the seismic hazard at Downtown Tehran. For instance, they identify the geometry of, and the rupture location on, adjacent faults, the shear wave velocity, and the intra-event residuals of ground motion prediction models as the most important sources of uncertainty. [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental work in order to evaluate the performance of a novel proposed retrofitting technique on a typical dome-roof adobe building by shaking table tests. For this purpose, two specimens, scaled 2:3, were subjected to a total of nine shaking table tests. The unretrofitted specimen, constructed by common practice, is designed to evaluate seismic performance and vulnerability of dome-roof adobe houses. The retrofitted specimen, exactly duplicating the first specimen, is retrofitted based on the results obtained from unretrofitted specimen tests, and the improvement in seismic behavior of the structure is investigated. Zarand earthquake (2005) Chatrood Station is selected as the input ground motion that was applied consecutively at 25, 100, 125, 150 and 175% of the design-level excitation. At 125% excitation level, the roof of the unretofitted specimen collapsed due to the walls' out-of-plane action and imbalanced forces. The retrofitting elements consist of eight horizontal steel rods drilled into the walls, passed through the specimen and bolted on the opposite wall surfaces. To improve walls in-plane seismic performance, welded steel mesh without using mortar, covered less than half area of walls on the external face of the walls, is used. In addition to strain gauges for recording steel rod responses, several instrumentations including acceleration and displacement transducers are implemented to capture response time histories of different parts of the specimens. The corresponding full-scaled retrofitted prototype tolerated peak acceleration of 0.62 g almost without any serious damage. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The seismic responses of steel water tanks are unconventional given their complex dynamic behavior and the sources of nonlinearity. Therefore, providing a reliable, finite-element model is instrumental in better understanding their dynamic behavior and improving the design conditions. This paper aims to evaluate the seismic performance of steel water tanks using shaking table tests and provide a finite-element reference model for simulating real-size, semi-anchored water tanks by conducting a series of large-scale tests in the Shaking Table Lab of the Sharif University of Technology (SUT). Since scaling the tank requires a difficult process involving changing the liquid density, this paper novelty lies in using the smallest real-size tank subjected to seismic motions. For this purpose, a full-scale tank is assembled in SUT's Shaking Table Lab per the Australian design code with some modifications. To evaluate the effect of water level on seismic performance, the test is conducted in four stages, each with a different ratio of water height to tank diameter. The stages are 0%, 30%, 50%, and 70%. To properly assess the effect of earthquake intensity on its seismic performance, the tank, undergoes three separate earthquake records in each stage, which are moderate, strong, and very strong levels of intensity. To further assess the performance of these tanks numerically and expand the results of the test, a finite-element model of the tank, water, and their interaction were also developed using Abaqus and then verified with the experimental data. Finally, the verified model is employed for evaluating the seismic performance of real-size steel tanks. [Display omitted] • Shaking table tests on full-scale semi-anchored steel water tank. • Create reference model to predict full-scale semi-anchored steel water tank responses. • Evaluating effects of filling ratio on seismic performance of tank with shaking table tests. • Evaluating the variation of acceleration profile and strains in steel water tanks. [ABSTRACT FROM AUTHOR]