Influence of soil——structure interaction on seismic collapse resistance of super-tall buildings

Numerous field tests indicate that the soilestructure interaction （SSI） has a significant impact on thedynamic characteristics of super-tall buildings, which may lead to unexpected structural seismic responsesand/or failure. Taking the Shanghai Tower with a total height of 632 m as the research object, thesubstructure approach is used to simulate the SSI effect on the seismic responses of Shanghai Tower. Therefined finite element （FE） model of the superstructure of Shanghai Tower and the simplified analyticalmodel of the foundation and adjacent soil are established. Subsequently, the collapse process of ShanghaiTower taking into account the SSI is predicted, as well as its final collapse mechanism. The influences ofthe SSI on the collapse resistance capacity and failure sequences are discussed. The results indicate that,when considering the SSI, the fundamental period of Shanghai Tower has been extended significantly,and the collapse margin ratio has been improved, with a corresponding decrease of the seismic demand.In addition, the SSI has some impact on the failure sequences of Shanghai Tower subjected to extremeearthquakes, but a negligible impact on the final failure modes. 2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

Expression of c-kit receptor in peripheral blood mononuclear cells in patients with systemic lupus erythematosus

Objective： To determine the expression of c-kit receptor in peripheral blood mononuclear cells （PBMCs） in patients with systemic lupus erythematosus （SLE）, and analyze the relationship between the c-kit expression level of PBMCs and clinical parameters. Methods： Peripheral blood mononuclear cells in 47 patients with SLE and 21 healthy volunteers were collected. Expression of c-kit mRNA in PBMCs were determined with reverse transcription-polymerase chain reaction （RT-PCR）. The protein of c-kit receptor （CDllT） in PBMCs was measured by flow cytometry. Results： Expression of c-kit receptor protein and mRNA in patients with active or inactive SLE （ n = 47） were significantly higher than those in controls. The c-kit receptor of PBMCs in SLE patients were significantly higher than those in healthy controls （ n = 21 ）, the c-kit receptor of PBMCs in active patients （ n = 27） were significantly higher than those in inactive patients （ n = 20） and there was no significant difference was found between patients with inactive SLE and healthy controls（ P 〉 0.05）. The c-kit receptor of PBMCs in SLE have significant association with activity index. Conclusion： Production of c-kit receptor is aberrantly increased in PBMCs in patients with SLE. C-kit receptor might be more closely related to the clinical parameters in SLE patients, which might reflect the clinical status of SLE patients.

Digital twin approach for enhancing urban resilience:A cycle between virtual space and the real world

Construction of disaster-resilient cities has attracted considerable attention.However,traditional methods of studying urban disaster resilience through experimental approaches are often constrained by various limitations,such as testing sites,costs and ethical considerations.To address these constraints,this paper proposes incor-porating digital twin concepts into urban disaster resilience research.By establishing a connection between the physical realm of the city and its virtual counterpart,this approach utilizes digital simulations to overcome the limitations of experimental methods and enables dynamic deduction and control of the disaster process.This pa-per delves into three key aspects encompassing the acquisition of data from reality to the virtual space,disaster simulation within the virtual space,and translation of virtual insights into effective disaster prevention strate-gies in reality.It provides a comprehensive summary of relevant research endeavors from the authors’research group and showcases the effectiveness and potential of the proposed techniques.These findings serve as refer-ences for pre-disaster planning,real-time emergency assessments,post-disaster rescue operations,and accident investigations for buildings and cities.

Editorial:From performance-based engineering to cityscape resilience

The resilience of our cityscapes hinges not only on the performance of individual structures and infrastructure but also on the strength of social,economic,and public institutions.These elements are vital for planning and mitigation design before disasters,immediate disaster re-sponse and the long-term recovery of communities.The built environ-ment,which underpins the daily activities and overall well-being of communities,faces a myriad of natural hazards.

Development and Application of a High-Performance Triangular Shell Element and an Explicit Algorithm in OpenSees for Strongly Nonlinear Analysis

The open-source finite element software,OpenSees,is widely used in the earthquake engineering community.However,the shell elements and explicit algorithm in OpenSees still require further improvements.Therefore,in this work,a triangular shell element,NLDKGT,and an explicit algorithm are proposed and implemented in OpenSees.Specifically,based on the generalized conforming theory and the updated Lagrangian formulation,the proposed NLDKGT element is suitable for problems with complicated boundary conditions and strong nonlinearity.The accuracy and reliability of the NLDKGT element are validated through typical cases.Furthermore,by adopting the leapfrog integration method,an explicit algorithm in OpenSees and a modal damping model are developed.Finally,the stability and efficiency of the proposed shell element and explicit algorithm are validated through the nonlinear time-history analysis of a highrise building.

Classification of New Biomarkers of Dilated Cardiomyopathy Based on Pathogenesis—An Update

Dilated Cardiomyopathy (DCM) is a complex heart disease affecting the heart musculature and vasculature, involving one or several underlying pathophysiological mechanisms. Identifying potential biomarkers for dilated cardiomyopathy is a challenge owing to various aetiologies involved. Studying the biomarkers involved in DCM will ultimately give a better insight about which pathophysiological pathways are involved in the onset of the disease. Owing to its multifactorial aetiologies, response to treatment is usually poor. If we can find the exact underlying causes, a better treatment approach could be implemented. One way to obtain better insight of DCM is to study the biomarkers released. Through biomarkers, we can know which underlying mechanisms are involved. Biomarkers can provide us with clinical information such as diagnostic, prognostic, risk stratification as well as response to treatment. Underlying mechanisms such as inflammation, stress/strain, myocyte injury, matrix remodelling, oxidative stress, neurohormones involvement, among others, can contribute to the onset of DCM. Different mechanisms will yield different biomarkers. So it would be wise to classify those biomarkers involving in DCM based on their respective pathogenesis. Moreover, most importantly is to be able to make use of the information that biomarker pertains. However, specificity of those biomarkers poses a problem. One way of making these biomarkers clinically useful is to make use of a biomarker modelling score system.

一种新型城市地震灾害模拟方法:城市抗震弹塑性分析方法

城市地震灾害模拟可服务震前防灾规划和震后快速救援,对降低城市震害风险具有重要价值.本研究提出了一种新型城市地震灾害模拟方法--城市抗震弹塑性分析方法,给出了海量建筑建模、高性能计算、"场地-城市效应"、高真实感可视化与次生灾害预测等系列关键科学问题的解决方法,并应用于震后灾损近实时评估(九寨沟)、震前防震减灾规划(唐山)、城市中心区高层建筑群多尺度震害模拟(北京CBD)、城市建筑震害及次生灾害全过程模拟(旧金山湾区)等,可为城市防震减灾提供重要决策参考.

A preliminary analysis and discussion of the condominium building collapse in surfside,Florida,US,June 24,2021

On June 24,2021,a 40-year-old reinforced concrete flat plate structure building in Miami suffered a sudden partial collapse.This study analyzed the overall performance and key components of the collapsed building based on the building design codes(ACI-318 and GB 50010).Punching shear and post-punching performances of typical slabcolumn joints are also studied through the refined finite element analysis.The collapse process was simulated and visualized using a physics engine.By way of these analyses,weak design points of the collapsed building are highlighted.The differences between the reinforcement detailing of the collapsed building and the requirements of the current Chinese code are discussed,together with a comparison of the punching shear and post-punching performances.The simulated collapse procedure and debris distribution are compared with the actual collapse scenes.

Regional seismic-damage prediction of buildings under mainshock-aftershock sequence

Strong aftershocks generally occur following a significant earthquake.Aftershocks further damage buildings weakened by mainshocks.Thus,the accurate and efficient prediction of aftershock-induced damage to buildings on a regional scale is crucial for decision making for post-earthquake rescue and emergency response.A framework to predict regional seismic damage of buildings under a mainshock-aftershock(MS-AS)sequence is proposed in this study based on city-scale nonlinear time-history analysis(THA).Specifically,an MS-AS sequence-generation method is proposed to generate a potential MS-AS sequence that can account for the amplification,spectrum,duration,magnitude,and site condition of a target area.Moreover,city-scale nonlinear THA is adopted to predict building seismic damage subjected to MS-AS sequences.The accuracy and reliability of city-scale nonlinear THA for an MS-AS sequence are validated by as-recorded seismic responses of buildings and simulation results in published literature.The town of Longtoushan,which was damaged during the Ludian earthquake,is used as a case study to illustrate the detailed procedure and advantages of the proposed framework.The primary conclusions are as follows.(1)Regional seismic damage of buildings under an MS-AS sequence can be predicted reasonably and accurately by city-scale nonlinear THA.(2)An MS-AS sequence can be generated reasonably by the proposed MS-AS sequencegeneration method.(3)Regional seismic damage of buildings under different MS-AS scenarios can be provided efficiently by the proposed framework,which in turn can provide a useful reference for earthquake emergency response and scientific decision making for earthquake disaster relief.

On the satisfiability of authorization requirements in business process

Satisfiability problem of authorization require- ments in business process asks whether there exists an as- signment of users to tasks that satisfies all the requirements, and methods were proposed to solve this problem. However, the proposed methods are inefficient in the sense that a step of the methods is searching all the possible assignments, which is time-consuming. This work proposes a method to solve the satisfiability problem of authorization requirements with- out browsing the assignments space. Our method uses im- proved separation of duty algebra （ISoDA） to describe a sat- isfiability problem of qualification requirements and quan- tification requirements （Separation of Duty and Binding of Duty requirements）. Thereafter, ISoDA expressions are re- duced into multi-mutual-exclusive expressions. The satisfia- bilities of multi-mutual-exclusive expressions are determined by an efficient algorithm proposed in this study. The experiment shows that our method is faster than the state-of-the-art methods.

Quantification of disaster resilience in civil engineering:A review

Resistance to unexpected disasters and rapid post-disaster recovery(i.e.,disaster resilience)of cities are extremely necessary owing to the concentrated risk of urbanization.Resilience quantification can adequately reflect the capacity of a city to withstand disasters.Many existing studies have focused on and proposed several frameworks on the quantitative measures of disaster resilience,and the corresponding research objects include different types of disasters(e.g.,earthquake,hurricane,flood,and fire),various domains(e.g.,engineering,social,and economic),and multiple levels(e.g.,city,community,and building).Among these research objects,studies on seismic resilience in civil engineering are relatively comprehensive.Specifically,studies on resilience in civil engineering have paid significant attention to the dynamics of engineering facilities and the engineering-related social and economic functions,including city-scale engineering,social,and economic functionalities,and essential functionalities of building,transportation,lifeline,and nonphysical subsystems of a city.Consequently,based on the review of resilience studies carried out in recent years,the framework and specifications for the quantification of disaster resilience of civil engineering systems subjected to earthquakes and other unexpected disasters are elaborated.Methods of disaster resilience assessment of cities and the corresponding subsystems are discussed.Furthermore,several case studies are reviewed,and resilience limit-state analyses of communities and buildings are performed.