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.

The Expanding Earth, Climate Engineering and Earthquake Processes

This article examines the issue of future directions of climate engineering in the light of the consequences of the Earth’s expansion process. One of the directions of climate engineering should be the study of seismic problems, because the state of the geosphere affects not only the atmosphere, but also the processes taking place in the bowels of the planet. If we accept the hypothesis of an expanding Earth [1], then rapid changes in meteorological conditions on the planet will become clear, and the secrets of earthquake processes will come out of the shadow of existing misconceptions among most geophysicists of the world and scientists will understand the mechanisms of energy formation of seismic processes. But, there are multiple arguments of world geophysicists testifying against the hypothesis of an expanding Earth, and in their opinion, scientists supporting this hypothesis allegedly did not provide mechanisms for the expansion of the planet [2]. In turn, the development of the theory of plate tectonics and the alleged discovery of the processes of formation of subduction zones led to the recognition of the hypothesis of plate tectonics by the world scientific community as the main theory of geophysics and sent science straight into a dead end of false conclusions, from which modern geophysics has not found a way out. And it was enough just to listen to A. Einstein and a march into the jungle of unfounded fantasies could be very easily avoided. Everything is extremely simple, but this makes it obvious and incomprehensible to most geophysicists that energy is matter, and matter is energy. For example, only the total amount of solar energy that our planet absorbs, including the atmosphere, land surface, and mirrors of the seas and oceans, is ~3,850,000 EJ per year [3]. And this is without taking into account the energy supply from space in the form of highly energetic particles. This scientific fact, which cannot be denied, must inevitably lead to the formation of matter and, consequently, to the expansion of the planet, because any high school student knows the physical concept of the equivalence of mass and energy arising from the theory of relativity A. Einstein [4], according to which the energy of a body at rest is equivalent to its mass multiplied by the square of the speed of light in a vacuum: E = mc2. That is, whether we like it or not, but the energy of the Sun and Space, as it has been transformed for billions of years into matter familiar to us: rocks, gases, minerals, fluids, will be transformed, in accordance with the laws of science. Otherwise, all the proponents of the expanding Earth hypothesis will have to declare that Mr. Einstein’s formula E = mc2 does not correspond to reality, and recognize the great scientist as a falsifier. Therefore, no matter what far-fetched arguments in the form of mythical subduction zones geophysicists give, no matter what “exotic laws of local significance” they invent, no matter how cynically they mock the fundamental laws of science—all energy entering the planet is necessarily processed and will be processed into matter with an increase in the volume of the planet. Without any exceptions! Only one biochemical process of photosynthesis continuously occurring in algae in one year brings ~3.6 × 1011 tons of oxygen into the Earth’s atmosphere [5], which significantly exceeds the amount of hydrogen and helium “immigrating” into space. Even if we take a geological epoch of one hundred million years, the evidence of an increase in the volume of the Earth only due to oxygen (3.6 × 1011 × 107 tons) becomes quite convincing. the surface area of the Earth is constantly increasing, then the processes of expansion of the planet increase exponentially, which inevitably leads to an increase in seismic activity and volcanic activity, and the increase in the volume of the planet itself serves as a lever for changing the meteorological conditions of the planet’s existence and one of the sources of seismic energy formation. In this article, we will consider seismic processes in the light of the expanding Earth hypothesis.

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.

ChatGPT in transforming communication in seismic engineering: Case studies, implications, key challenges and future directions

Seismic engineering,a critical field with significant societal implications,often presents communication challenges due to the complexity of its concepts.This paper explores the role of Artificial Intelligence(AI),specifically OpenAI’s ChatGPT,in bridging these communication gaps.The study delves into how AI can simplify intricate seismic engineering terminologies and concepts,fostering enhanced understanding among students,professionals,and policymakers.It also presents several intuitive case studies to demonstrate the practical application of ChatGPT in seismic engineering.Further,the study contemplates the potential implications of AI,highlighting its potential to transform decision-making processes,augment education,and increase public engagement.While acknowledging the promising future of AI in seismic engineering,the study also considers the inherent challenges and limitations,including data privacy and potential oversimplification of content.It advocates for the collaborative efforts of AI researchers and seismic experts in overcoming these obstacles and enhancing the utility of AI in the field.This exploration provides an insightful perspective on the future of seismic engineering,which could be closely intertwined with the evolution of AI.

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.

Application of dynamic analysis of strength reduction in the slope engineering under earthquake

At present,the methods of analyzing the stability of slope under earthquake are not accurate and reasonable because of some limitations. Based on the real dynamic tensile-shear failure mechanism of slope,the paper proposes dynamic analysis of strength reduction FEM (finite element method) and takes the reduction of shear strength parameters and tensile strength parameters into consideration. And it comprehensively takes the transfixion of the failure surface,the non-convergence of calculation and mutation of displacement as the criterion of dynamic instability and failure of the slope. The strength reduction factor under limit state is regarded as the dynamic safety factor of the slope under earthquake effect and its advantages are introduced. Finally,the method is applied in the seismic design of anchors supporting and anti-slide pile supporting of the slope. Calculation examples show that the application of dynamic analysis of strength reduction is feasible in the seismic design of slope engineering,which can consider dynamic interaction of supporting structure and rock-soil mass. Owing to its preciseness and great advantages,it is a new method in the seismic design of slope supporting.

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 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 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.