Performance-based seismic design of nonstructural building components:The next frontier of earthquake engineering

With the development and implementation of performance-based earthquake engineering,harmonization of performance levels between structural and nonstructural components becomes vital. Even if the structural components of a building achieve a continuous or immediate occupancy performance level after a seismic event,failure of architectural,mechanical or electrical components can lower the performance level of the entire building system. This reduction in performance caused by the vulnerability of nonstructural components has been observed during recent earthquakes worldwide. Moreover,nonstructural damage has limited the functionality of critical facilities,such as hospitals,following major seismic events. The investment in nonstructural components and building contents is far greater than that of structural components and framing. Therefore,it is not surprising that in many past earthquakes,losses from damage to nonstructural components have exceeded losses from structural damage. Furthermore,the failure of nonstructural components can become a safety hazard or can hamper the safe movement of occupants evacuating buildings,or of rescue workers entering buildings. In comparison to structural components and systems,there is relatively limited information on the seismic design of nonstructural components. Basic research work in this area has been sparse,and the available codes and guidelines are usually,for the most part,based on past experiences,engineering judgment and intuition,rather than on objective experimental and analytical results. Often,design engineers are forced to start almost from square one after each earthquake event: to observe what went wrong and to try to prevent repetitions. This is a consequence of the empirical nature of current seismic regulations and guidelines for nonstructural components. This review paper summarizes current knowledge on the seismic design and analysis of nonstructural building components,identifying major knowledge gaps that will need to be filled by future research. Furthermore,considering recent trends in earthquake engineering,the paper explores how performance-based seismic design might be conceived for nonstructural components,drawing on recent developments made in the field of seismic design and hinting at the specific considerations required for nonstructural components.

Airblast evolution initiated by Wangjiayan landslides in the M_(s)8.0 Wenchuan earthquake and its destructive capacity analysis

Airblasts,as one common phenomenon accompanied by rapid movements of landslides or rock/snow avalanches,commonly result in catastrophic damages and are attracting more and more scientific attention.To quantitatively analyze the intensity of airblast initiated by landslides,the Wangjiayan landslide,occurred in the Wenchuan earthquake,is selected here with the landslide propagation and airblast evolution being studied using FLUENT by introducing the Voellmy rheological law.The results reveal that:(1)For the Wangjiayan landslide,its whole travelling duration is only 12 s with its maximum velocity reaching 36 m/s at t=10 s;(2)corresponding to the landslide propagation,the maximum velocity,28 m/s,of the airblast initiated by the landslide also appears at t=10 s with its maximum pressure reaching594.8 Pa,which is equivalent to violent storm;(3)under the attack of airblast,the load suffered by buildings in the airblast zone increases to 1300 Pa at t=9.4 s and sharply decreased to-7000 Pa as the rapid decrease of the velocity of the sliding mass at t=10 s,which is seriously unfavorable for buildings and might be the key reason for the destructive collapse of buildings in the airblast zone of the Wangjiayan landslide.

Analysis of debris flow control effect and hazard assessment in Xinqiao Gully,Wenchuan M_(s)8.0 earthquake area based on numerical simulation

Xinqiao Gully is located in the area of the 2008 Wenchuan M_(s)8.0 earthquake in Sichuan province,China.Based on the investigation of the 2023"6-26"Xinqiao Gully debris flow event,this study assessed the effectiveness of the debris flow control project and evaluated the debris flow hazards.Through field investigation and numerical simulation methods,the indicators of flow intensity reduction rate and storage capacity fullness were proposed to quantify the effectiveness of the engineering measures in the debris flow event.The simulation results show that the debris flow control project reduced the flow intensity by41.05%to 64.61%.The storage capacity of the dam decreases gradually from upstream to the mouth of the gully,thus effectively intercepting and controlling the debris flow.By evaluating the debris flow of different recurrence intervals,further measures are recommended for managing debris flow events.

Earthquake engineering research needs in light of lessons learned from the 2011 Tohoku earthquake

Earthquake engineering research and development have received much attention since the first half of the twentieth century. This valuable research presented a huge step forward in understanding earthquake hazard mitigation,which resulted in appreciable reduction of the effects of past earthquakes. Nevertheless,the 2011 Tohoku earthquake and the subsequent tsunami resulted in major damage. This paper presents the timeline of earthquake mitigation and recovery,as seen by the authors. Possible research directions where the authors think that many open questions still remain are identified. These are primarily based on the important lessons learned from the 2011 Tohoku earthquake.

A statistical approach to determine 2D optimal equivalent linear parameters with application to earthquake engineering

The equivalent linearization method approximates the maximum displacement response of nonlinear structures through the corresponding equivalent linear system. By using the particle swarm optimization technique, a new statistical approach is developed to determine the key parameters of such an equivalent linear system over a 2D space of period and damping ratio. The new optimization criterion realizes the consideration of the structural safety margin in the equivalent linearization method when applied to the performance-based seismic design/evaluation of engineering structures. As an application, equations for equivalent system parameters of both bilinear hysteretic and stiffness degrading single-degree-of- freedom systems are deduced with the assumption of a constant ductility ratio. Error analyses are also performed to validate the proposed approach.

Earthquake engineering in China

The development of earthquake engineering in China is described into three stages.The initial stage in 1950's- 1960's was marked with the initiation of this branch of science from its creation in the first national 12-year plan of science and technology by specifying earthquake engineering as a branch item and IEM was one participant.The first earthquake zonation map and the first seismic design code were soon completed and used in engineering design.Site effect on structural design and site selection were seriously studied.The second stage marked with the occurrence of quite a few strong earthquakes in China, from which many lessons were learned and corresponding considerations were specified in our design codes and followed in construction practice.The third stage is a stage of disaster management,which is marked by a series of government documentations,leading by a national law of the People's Republic of China on the protecting against and mitigating earthquake disasters adopted at the meeting of the Standing Committee of the National People's Congress of the People's Republic of China in 1997,and then followed by some provincial and municipal laws to force the actions outlined in the national law.It may be expected that our society will be much more safer to resist the attack of future strong earthquakes with less losses.Lastly, possible future developments are also discussed.

Earthquake Engineering and Engineering Vibration AIMS AND SCOPE

This journal is established by the Institute of Engineering Mechanics (IEM), China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation, preparedness, and recovery.

Earthquake Engineering and Engineering Vibration

Journal web site:http://www.springerlink.comAIMS AND SCOPE This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and

EARTHQUAKE ENGINEERING AND ENGINEERING VIBRATION

Copyright Submission of a manuscript implies:that the work described has not been published before(except in the form of an abstract or as part of a published lecture,review,or thesis);that it is not under consideration for publication elsewhere;that its publication has been approved by all co-authors,if any,as well as-tacitly or explicitly-by the responsible authorities at the institution where the work was carried out.The author warrants that his/her

EARTHQUAKE ENGINEERING AND ENGINEERING VIBRATION

Copyright Submission of a manuscript implies： that the work described has not been published before （except in the fon＇n of an abstract or as part of a published lecture, review, or thesis）; that it is not under consideration for publication ersewhere： that its publication has been approved by all co-authors, if any, as well as - tacitly or explicitly - by the responsible authorities at the institution where the work was carried out.

EARTHQUAKE ENGINEERING AND ENGINEERING VIBRATION

Copyright Submission of a manuscript implies: that the work described has not been published before (except in the form of an abstract or as part of a published lecture, review, or thesis); that it is not under

EARTHQUAKE ENGINEERING AND ENGINEERING VIBRATION

Submission of a manuscript implies： that the work described has not been published before （except in the form of an abstract or as part of a published lecture, review, or thesis）; that it is not under consideration for publication elsewhere; that its publication has been approved by all co-authors, if any, as well as - tacitly or explicitly - by the responsible authorities at the institution where the work was carried out.

EARTHQUAKE ENGINEERING AND ENGINEERING VIBRATION

Copyright Submission of a manuscript implies: that the work described has not been published before (except in the form of an abstract

Earthquake Engineering and Engineering Vibration

Copyright Submission of a manuscript implies:that the work described has not been published before(except in the form of an abstract or as part of a published lecture,review,or thesis);that it is not under consideration for publication elsewhere;that its publication has been approved by all co-authors,if any,as well as-tacitly or explicitly-by the responsible authorities at the institution where the work was carried out.The author warrants that his/her

Earthquake Engineering and Engineering Vibration

Journal web site:http://www.springerlink.comAIMS AND SCOPE This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.

EARTHQUAKE ENGINEERING AND ENGINEERING VIBRATION

Copyright Submission of a manuscript implies： that the work described has not been published before （except in the form of an abstract or as part of a published lecture, review, or thesis）; that it is not under consideration for publication elsewhere; that its publication has been approved by all co-authors, if any, as well as - tacitly or explicitly - by the responsible authorities at the institution where the work was carried out. The author warrants that his/her contribution is original and that he/she has full power to make this grant. The author signs for and accepts responsibility for releasing this material on behalf of any and all co-authors. Transfer of copyright to Institute of Engineering Mechanics, China Earthquake Administration and Springer becomes effective if and when the article is accepted for publication. After submission of the Copyright Transfer Statement signed by the corresponding author, changes of authorship or in the order of the authors listed will not be accepted by Institute of Engineering Mechanics, China Earthquake Administration and Springer. The copyright covers the exclusive right （for U.S. government employees： to the extent transferable） to reproduce and distribute the article, including reprints, translations, photographic reproductions, microform, electronic form （offline, online） or other reproductions of similar nature.

EARTHQUAKE ENGINEERING AND ENGINEERING VIBRATION. AIMS AND SCOPE

This journal, published biannually, is established by the Institute of Engineering Mechanics (IEM), China Earthquake Administration, in cooperation with the Multidisciplinary Center for Earthquake Engineering Research (MCEER), University at Buffalo, State University of New York, to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation, preparedness, and recovery.