From the editors

Dear Members of the Editorial Board, Contributors and Friends of the journal,This issue of Earthquake Engineering and Engineering Vibration(Vol. 23, No. 2) includes five papers in a special section entitled “Wave-Based Nondestructive Testing and Evaluation Methods in Civil Engineering”. The special section aims to present recent developments and applications of wave-based nondestructive testing and evaluation research. We thank the guest editors, Prof. Nenad Gucunski of Rutgers University, USA, Prof. Lin Shibin of Jianghan University, China and Prof. Chen Hongbing, University of Science and Technology Beijing, China, for their hard work and dedication.

Near-fault ground motions with prominent acceleration pulses:pulse characteristics and ductility demand

Major earthquakes of last 15 years （e.g., Northridge 1994, Kobe 1995 and Chi-Chi 1999） have shown that many near-fault ground motions possess prominent acceleration pulses. Some of the prominent ground acceleration pulses are related to large ground velocity pulses, others are caused by mechanisms that are totally different from those causing the velocity pulses or fling steps. Various efforts to model acceleration pulses have been reported in the literature. In this paper, research results from a recent study of acceleration pulse prominent ground motions and an analysis of structural damage induced by acceleration pulses are summarized. The main results of the study include： （1） temporal characteristics of acceleration pulses; （2） ductility demand spectrum of simple acceleration pulses with respect to equivalent classes of dynamic systems and pulse characteristic parameters; and （3） estimation of fundamental period change under the excitation of strong acceleration pulses. By using the acceleration pulse induced linear acceleration spectrum and the ductility demand spectrum, a simple procedure has been developed to estimate the ductility demand and the fundamental period change of a reinforced concrete （RC） structure under the impact of a strong acceleration pulse.

Three dimensional temporal characteristics of ground motions and building responses in Wenchuan earthquake

In this paper, analytical results from 3D temporal characteristics of the responses of an RC frame building subjected to both a large aflershock and the main shock of Wenchuan M8.0 earthquake are presented. The ground motion records from the main shock were obtained from three nearby stations. The acceleration records were analyzed in terms of instantaneous tangential acceleration αv normal acceleration αN, Euclidean norm of acceleration vector lal, velocity vector ｜v｜, displacement vector ｜d｜, temporal curvature κ,κt, and temporal torsion γ and γt.Results of the kinematic relationship between the above factors and some additional in depth information obtained from extensive analyses are provided and discussed.