In this paper the use of the Hilbert-Huang Transform (HHT), for the decomposition and characterization of seismic ground response, is discussed. The HHT, integrated by the Empirical Mode Decomposition (EMD) and the Hilbert Transformation (HT), enables engineers to analyze non-stationary oscillation systems and to obtain more detailed intensity descriptions on time-varying frequency diagrams. Th...

Recorded ground motions in near fault region have completely distinct nature from others that recorded in far field of the fault. Near source outcomes cause much of the seismic energy to appear in a single large and long period pulse at the beginning of the velocity record. Assaluyeh complex is located near the reverse Assaluyeh fault that is a segment of Mountain Front Fault. This complex cont...

This paper presents the formulation of a time-dependent seismic fragility format for bridges, as well as new insights into the potential effects of aging and deterioration on seismic vulnerability traditionally neglected in fragility modeling, including joint impacts of multiple component deterioration not investigated to date. The study evaluates the impact of lifetime exposure to chlorides fr...

in this paper, the consequences of well-known characteristics of near-fault ground motions, forward directivity and fling step, on the seismic response control is investigated. an integrated fuzzy rule-based control strategy for building structures incorporated with semi active friction damping system with amplifying braces (fdsab) is developed. the membership functions and fuzzy rules of fuzzy...

Simplified procedures are commonly employed to estimate seismic displacements of earth and waste fills. The landmark work of Makdisi and Seed (1978) has been widely adopted in practice. Although this work is widely used, it has a number of significant limitations such as decoupling the sliding block analysis from the seismic response analysis, use of a limited number of recorded earthquake moti...

The finite element model of suspension bridge was established according to the actual engineering in Southwest area China. In order simulate random ground motion accurately and efficiently, orthogonal function modeling method based on Priestley evolution spectrum theory is adopted. dimensionality reduction simulation realized, simulated samples are input into carry out time history analysis. Fi...

Irregularities in bridge pier stiffness concentrate the ductility demand on short piers; while not operating on the longer and more flexible ones. The existence of non-uniform, ductility demand distribution in bridges significantly influences seismic response. As such, this paper proposes a new approach for balancing the ductility demand in irregular bridges by utilizing shape memory alloys (SM...

This paper presents a practical methodology for optimization of concentrically braced steel frames subjected to forward directivity near-fault ground motions, based on the concept of uniform deformation theory. This is performed by gradually shifting inefficient material from strong parts of the structure to the weak areas until a state of uniform deformation is achieved. In this regard, to ove...

[1] Predicting accurate ground motion is critical for earthquake hazard analysis, particularly in situations where sedimentary basins trap and amplify seismic waves. We exploit the information carried by the ambient seismic field to extract surface-wave Green’s functions between seismic stations and to predict long-period ground motion from earthquakes. To do so, we modify the surface impulse r...