During the 2011 Tohoku Earthquake, gymnasium buildings sustained unexpected structural damage, preventing their use as evacuation shelters. This study examines one such severely damaged structure with fewer connections between steel roof and reinforced concrete columns. Results of eigenvalue, pushover, seismic response analyses elucidate observed damage. The out-of-plane deformation is prominen...

tuned liquid dampers (tld) are among passive control devices that have been used to suppress the vibration of structures in recent years. these structures must be adequately presentable as an equivalent single degree of freedom system with long fundamental period. the tld, located at the top floors of the structure, can dissipate the external input energy into the system through the sloshing ef...

Pile foundation bridges are structures extending in the middle of sea, so they subject to currents, waves, and earthquake forces. This article presents a hybrid simulation that was used with input excitations different current velocities, wave properties, amplitudes assess non-linear dynamic behavior pile bridge piers. Based on interface between MATLAB ABAQUS software, general formulations flui...

We present a comprehensive study of the Earth’s gravest spheroidal modes excited by the Maule, Chile, earthquake of 27 February 2010, using uninterrupted time series extending over a minimum of 19 and a maximum of 93 days. For each of 101 station–mode combinations, we use the formalism of Stein and Geller (1977) to compute the relative excitation of the 2l 1 singlets in the relevant geometry an...

Wave travel times of vertically propagating waves are measured in the Van Nuys 7-storey hotel, located in the Los Angeles metropolitan area, from impulse response functions computed by deconvolution of the recorded earthquake response. East-West response data from 11 earthquakes over a period of 24 years are analysed. Changes in wave travel times are used to infer about local (between sensors) ...

Within the past decade, seismic isolation systems have gained rapid popularity in the earthquake resistant design of bridge structures. This popularity has come in response to the inadequacy of earlier seismic design and retrofit methodologies. The mechanical shortcomings and subsequent failure mechanisms associated with the early elastic seismic design philosophy are first presented, followed ...

A novel energy-dissipation system for frame-core tube structure equipped with damped outriggers is studied experimentally. A steel frame-core tube structure model is designed and manufactured, in which viscous dampers are inserted vertically between the outrigger and fame columns to make full use of motion discrepancy of these two components. Shaking table tests of the building with damped or f...

A new optimization concept is introduced which involves the optimization of non-linear planar shear buildings by using gradients based on equivalent linear structures, instead of the traditional practice of calculating the gradients from the non-linear objective function. The optimization problem is formulated as an equivalent linear system of equations in which a target fundamental eigenfreque...