This report investigates the issue of selecting and scaling ground motions as input excitations for response history analyses of buildings in performance-based earthquake engineering. Many ground motion selection and modification (GMSM) procedures have been developed to select ground motions for a wide variety of objectives. This report focuses on the selection and scaling of single, horizontal...

earthquake ground-motions show significant variability in both spectral and temporal characteristics. procedures to generalize and predict strong ground motions may be generally divided into three main disciplines: numerical techniques based on a kinematic source description, empirical attenuation models, and semi-empirical stochastic models. numerous studies have shown that, in the near-fault ...

The use of precast post-tensioned segmental (PPS) piers is growing in the bridge industry, particularly Accelerated Bridge Construction (ABC). To increase their high-seismicity regions, this study focuses on seismic performance PPS under pulse-like near-field earthquakes. Two ensembles 40 ground motions and 44 far-field along with three various heights are used a series incremental dynamic anal...

Near-fault ground motions are different from ordinary ground motions in that they often contain strong coherent dynamic long period pulses and permanent ground displacements. The dynamic motions are dominated by a large long period pulse of motion that occurs on the horizontal component perpendicular to the strike of the fault, caused by rupture directivity effects. Near fault recordings from r...

This study focuses on developing fragility-based seismic vulnerability assessment techniques for seismically retrofitted multi-column bridge bent. Fragility curves are developed using Probabilistic Seismic Demand Model (PSDM) to assess the relative performance of different retrofit methods under near fault ground motions. Two different retrofit techniques namely CFRP jacketing and ECC jacketing...

Since charge-transfer-to-solvent ~CTTS! reactions represent the simplest class of solvent-driven electron transfer reactions, there has been considerable interest in understanding the solvent motions responsible for electron ejection. The major question that we explore in this paper is what role the symmetry of the electronic states plays in determining the solvent motions that account for CTTS...

This paper compares base shear computed from floor accelerations (inertial base shear) and column shears (structural base shear) for several single-degree-of-freedom (SDF) systems and two mid-rise, multi-story buildings due to a suite of 30 earthquake ground motions. The presented results show that the inertial base shear is close to structural base shear in short-period (<1 sec) SDF systems bu...

To rank the pulse-like ground motions based on damage potential to different structures, internal relationship between of and engineering demand parameters (EDPs) is analyzed in this paper. First, a total 240 from NGA-West2 database 16 intensity measures (IMs) are selected. Moreover, four reinforced concrete frame structures with significantly natural vibration periods established for dynamic a...

Dynamic Ratcheting (DR) is a nonlinear dynamic phenomenon occurring in hysteretic damping systems. It means the structural plastic deformation increases asymmetrically in successive cycles under an earthquake excitation. Although it is generally recognized that DR is closely related to the frequency contents of an earthquake excitation applied to thestructure, no targeted analysis has bee...