Comparison of engineering failures and seismic responses of 500 kV transformer-bushing systems in the 2022 Luding earthquake

Cemented and mechanically clamped types of end fittings(fitting-C and fitting-M)are commonly used in transformer bushings.During the Luding Ms 6.8 earthquake that occurred in China on September 5,2022,all transformer bushings with the two types of end fittings in a 500 kV substation were damaged.Post-earthquake field investigations were conducted,and the failures of the two types of bushings were compared.Two elementary simulation models of the transformer-bushing systems were developed to simulate the engineering failures,and further compute their seismic responses for comparison.The results indicate that the hitch lugs of the connection flange are structurally harmful to seismic resistance.Fitting-M can decrease the bending stiffness of the bushing due to the flexible sealing rubber gasket.Since it provides a more flexible connection that dissipates energy,the peak accelerations and relative displacements at the top of the bushing are significantly lower than those of the bushing with fitting-C.Compared with fitting-C,fitting-M transfers the high-stress areas from the connection flange to the root of the porcelain,so the latter becomes the most vulnerable component.Fitting-M increases the failure risk of the low-strength porcelain,indicating the unsuitability of applying it in high-intensity fortification regions.

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.

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.

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.

Development of a building information model-guided post-earthquake building inspection framework using 3D synthetic environments

Computer vision-based inspection methods show promise for automating post-earthquake building inspections.These methods survey a building with unmanned aerial vehicles and automatically detect damage in the collected images.Nevertheless,assessing the damage′s impact on structural safety requires localizing damage to specific building components with known design and function.This paper proposes a BIM-based automated inspection framework to provide context for visual surveys.A deep learning-based semantic segmentation algorithm is trained to automatically identify damage in images.The BIM automatically associates any identified damage with specific building components.Then,components are classified into damage states consistent with component fragility models for integration with a structural analysis.To demonstrate the framework,methods are developed to photorealistically simulate severe structural damage in a synthetic computer graphics environment.A graphics model of a real building in Urbana,Illinois,is generated to test the framework;the model is integrated with a structural analysis to apply earthquake damage in a physically realistic manner.A simulated UAV survey is flown of the graphics model and the framework is applied.The method achieves high accuracy in assigning damage states to visible structural components.This assignment enables integration with a performance-based earthquake assessment to classify building safety.

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 form of an abstract or as part of a published lecture, review, or thesis); that it is not under

EARTHQUAKE ENGINEERING AND ENGINEERING VIBRATION

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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

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

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. 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.

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.

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.To accomplish this purpose,the journal aims to