Quantitative evaluation and improvement of seismic resilience of a tall frame shear wall structure

Tall buildings are an important part of a city, and their earthquake-induced damage or collapse will lead to heavy losses, extended repair time, and casualties. Therefore, it is essential to quantify and improve the resilience of tall buildings. To this end, this paper develops a component damage-based metric to characterize tall buildings' functionality loss and then proposes a general quantitative evaluation process to evaluate tall buildings' resilience. Next, the evaluation process is applied to a 42-story reinforced concrete frame shear wall building to demonstrate its applicability. Finally, retrofit strategies on nonstructural components are discussed to enhance the building's resilience. It can be concluded that the proposed metric can be effectively used to evaluate tall buildings' functionality loss. The building being studied has great seismic resilience, with resilience values of 99.95%, 98.68%, and 88.69% at service level earthquake (SLE), design level earthquake (DBE), and maximum considered earthquake (MCE), respectively. The influence of nonstructural components on seismic resilience is greater than that of structural components at SLE and DBE levels. It is an effective alternative to enhance the seismic resilience of tall buildings under SLE and DBE by improving the performance of partition walls, ceilings, and equipment.     

GB/T 38591—2020《建筑抗震韧性评价标准》与国际相关标准对比研究

建筑抗震韧性是指建筑结构在设定水准地震作用后维持和迅速恢复使用功能的能力。建立系统化的抗震韧性评价方法是建设抗震韧性建筑乃至韧性城市的重要组成部分。国际上从2012年起提出和发展了建筑抗震韧性评价方法,形成了多本韧性评价标准或指南。中国GB/T 38591—2020《建筑抗震韧性评价标准》于2020年3月31日发布,将于2021年2月1日起实行。为了对比GB/T 38591—2020与国际相关标准所评定的建筑抗震韧性水平,介绍了建筑抗震韧性评价方法的发展和基本流程,说明并比较了各标准计算韧性指标的不同策略,包括建筑修复费用、建筑修复时间和人员伤亡。采用算例说明了修复策略、次序和工人数量对建筑修复时间的显著影响,并对比了不同标准划定韧性建筑等级的判别标准。分析发现,GB/T 38591—2020在计算建筑修复时间、人员伤亡和判定抗震韧性等级方面与国际相关标准差别显著,且其所包含的不确信性范围小于国际相关标准。GB/T 38591—2020所评定的一星建筑的韧性水平约等同于或略高于REDi的银级建筑或USRC的4星建筑。     

高层钢结构不同减震加固方案的抗震韧性评估

随着既有建筑减震加固需求的不断增加,如何从抗震韧性的新角度评估减震加固方案的合理性成为一个需要关注的问题。该文以一栋高层钢结构减震加固为例,从抗震韧性的角度对两种减震方案进行对比。首先基于数学算法,从PEER(Pacific Earthquake Engineering Research Center)地震动数据库中选取20条地震波,使所选地震动的加速度反应谱均值和目标谱吻合,并实现每条反应谱在结构基本周期点和目标谱完全吻合;通过3000次蒙特卡洛模拟,得到修复费用、修复时间和伤亡率的对数正态分布函数,并取84%分位值作为代表值,以比较两种加固方案的优劣;提出加固收益率的概念,并从加固收益的角度重新评估两种方案的经济效益,结果表明阻尼器较多的加固方案可能造成加固成本大于修复成本,使阻尼器数量较少的加固方案更加经济合理。该文的工作是抗震韧性在减震加固中方案评估中的应用,完善减震加固理论体系,为抗震韧性的在减震加固工程中的应用提供借鉴。     

基于建筑抗震韧性评价标准的某教学楼抗震韧性评价分析

对传统抗震设防目标和"可恢复功能"的抗震设计理念进行了介绍,采用新编国家标准《建筑抗震韧性评价标准》中的评价方法,对一栋新建小学教学楼进行了抗震韧性评价分析,对其修复费用、修复时间和人员损失进行了评估,以确定其抗震韧性等级。结果表明,抗震韧性评价可以对建筑物抗震性能进行量化分析,提供更易理解且更有价值的性能指标;同时,抗震韧性评价可以更加直观地验证"三水准"抗震设防目标,并发现非结构构件往往是造成人员伤亡和抗震修复代价的主要因素。     

钢筋混凝土框架核心筒结构地震韧性评价

随着中国高层建筑的蓬勃发展,“大震不倒”的性能目标已经不能满足现代社会的需求,提高其地震韧性是当下高层建筑抗震的发展趋势。对比目前代表性的韧性计算方法,构建了一种基于构件损伤状态的结构使用功能量化方法,提出了结构地震韧性的评价流程,并应用于典型钢筋混凝土框架核心筒高层建筑结构的地震韧性评价。研究结果表明：所提出的基于构件损伤状态的使用功能量化方法能较好地反映结构在不同地震水准下的使用功能损失;钢筋混凝土框架核心筒结构算例具有较好的地震韧性,在多遇、设防和罕遇地震水准下的韧性分别为99.95%、98.68%和88.69%,在多遇和设防地震水准下,非结构构件对钢筋混凝土框架核心筒结构算例地震韧性的影响明显大于结构构件。     

Experimental study on a novel replaceable yielding‐based energy dissipater for rocking and seesaw buildings

The use of energy dissipaters for creation of earthquake‐resilient buildings has been paid more and more attention in recent years, and some newly developed structural fuses or dampers have been proposed to be employed in rocking and seesaw buildings. In this study, a new type of yielding‐based dampers, called curved‐yielding‐plates energy dissipater (CYPED), is introduced. CYPEDs are installed at the bottom of rocking or seesaw building's circumferential columns at the lowest story and have hysteretic behavior in their deformation occurring in vertical direction. The initial curvature of the yielding plates prevents them from buckling and gives the device a smooth force–deformation behavior. First, by performing a set of cyclic tests on three specimens of CYPED, their hysteretic force–displacement behavior was investigated. Then, to show the efficiency of this energy dissipating device in reducing the seismic response of buildings, they were employed numerically as multilinear plastic springs in the computer models of a sample seesaw steel building, and a series of nonlinear time history analysis (NLTHA) were performed on both seesaw building and its conventional counterpart. Results of NLTHA show that the proposed seesaw structural system equipped with appropriate CYPEDs not only gives the building a longer natural period, leading to lower seismic demand, but also leads to remarkable energy dissipation capacity in the building structure at base level and, therefore, keeping the seismic drifts in elastic range in all stories of the building. In this way, the building structure does not need any major repair work, even after a large earthquake, while the conventional building suffers from heavy damage and is not usable after the earthquake.     

Multi-objective optimization for community building group recovery scheduling and resilience evaluation under earthquake

The building group is the basis for the maintenance and operation of the city. The rapid recovery of community building group (CBG) can effectively reduce economic losses caused by earthquakes. There is service function interdependence among the buildings, and the impact of this interdependence on the postdisaster recovery of CBG is not clear. In order to improve the postdisaster recovery efficiency of CBG and explore the impact of service function dependence among buildings on postdisaster recovery, this paper integrates the recovery time (RT) and functionality loss (FL) of individual buildings and proposes two multi-objective optimization recovery models suitable for CBG: the postearthquake recovery optimization model of CBG and the postearthquake recovery optimization model of CBG considering the service function interdependence among buildings. In these models, building RT, building FL, CBG resilience, and building recovery resources are considered, and the nondominated sorting genetic algorithm-Ⅱ is used to solve the models to obtain the optimal restoration scheduling of CBG. At the same time, through a case, this paper analyzes the impact of the interdependence of service function among buildings and recovery resources on the recovery scheduling and resilience of CBG. This method can provide a basis for pre-earthquake disaster risk reduction planning and significantly improves the postdisaster recovery efficiency of CBG.     

大型公共建筑非结构构件抗震性能及#br# 韧性提升研究综述

大型公共建筑既是保障震后救灾及城市系统功能恢复的基础设施系统,又是地震灾害的重要承灾体。地震一旦发生,大型公共建筑中非结构构件会造成严重的地震灾害,影响建筑的使用功能、造成巨大的经济损失,甚至给人员疏散和安置带来潜在威胁。文章从理论分析、数值模拟及试验研究等3个方面系统总结非结构构件抗震性能分析方法的研究进展。以吊顶、幕墙及电梯为例阐述非结构构件的地震响应及破坏特征。探讨大型公共建筑中非结构构件抗震性能研究的新思路：结合材料科学、控制科学及交叉学科的发展,不断创新非结构构件的抗震性能分析方法;结合大数据和人工智能技术形成非结构构件震害评价方法和智能识别技术,为非结构构件的抗震韧性评估提供依据;发展非结构构件地震韧性提升技术,为大型公共建筑的安全运行提供技术保障。     

学校建筑的砌体结构抗震设计建议

结合汶川地震震害调查情况及西北地区建筑物现状,对抗震规范中的砌体结构抗震设计缺陷提出了修改建议;对建筑物的层数、整体性能及抗震概念设计提出了的设计建议,对提高学校建筑抗震设计具有一定的借鉴作用。     

GB/T 38591-2020《建筑抗震韧性评价标准》解读

近年来,美国和日本等国家相继提出了城市抗震韧性的概念并进行了相关研究,对建筑结构的抗震性能要求由"安全性"提升到了"韧性"的层面.我国市场监督管理总局和标准化管理委员会于2020年3月31日联合发布了GB/T 38591-2020《建筑抗震韧性评价标准》,该标准将于2021年2月1日实施.为了帮助使用者更深入地理解标准...     

城市抗震韧性评估研究进展

现阶段，我国大城市与城市群内人员和社会财富高度密集，基础设施林立，城市地震安全问题严重威胁着我国新型城镇化战略的实施，灾害脆弱性已经成为现阶段城镇化进程中制约城市可持续发展的核心问题，实现工程设施、城市乃至整个社会的抗震韧性已经成为国际地震工程界的共识。抗震韧性城市的研究涉及地震学、土木工程、人工智能、遥感技术、社会学、经济学、管理学等多个学科，是一项极具挑战性的课题。文中阐明了城市抗震韧性的定义，系统总结了城市抗震韧性评估的国内外研究现状，并提出了建设抗震韧性城市所涉及到的科学技术问题及韧性能力提升策略。     

Approximate method of estimating seismic performance of high‐rise buildings with oil‐dampers

When subjected to long‐period ground motions, many existing high‐rise buildings constructed on plains with soft, deep sediment layers experience severe lateral deflection, caused by the resonance between the long‐period natural frequency of the building and the long‐period ground motions, even if they are far from the epicenter. This was the case for a number of buildings in Tokyo, Nagoya, and Osaka affected by the ground motions produced by the 2011 off the Pacific coast of Tohoku earthquake in Japan. Oil‐dampers are commonly used to improve the seismic performance of existing high‐rise buildings subjected to long‐period ground motion. This paper proposes a simple but accurate analytical method of predicting the seismic performance of high‐rise buildings retrofitted with oil‐dampers installed inside and/or outside of the frames. The method extends the authors' previous one‐dimensional theory to a more general method that is applicable to buildings with internal and external oil‐dampers installed in an arbitrary story. The accuracy of the proposed method is demonstrated through numerical calculations using a model of a high‐rise building with and without internal and external oil‐dampers. The proposed method is effective in the preliminary stages of improving the seismic performance of high‐rise buildings.     

Assessment of inelastic response of buildings using force‐ and displacement‐based approaches

In recognition of the increasing importance of accurate seismic vulnerability assessment, this paper deals with procedures and the application of inelastic acceleration and displacement spectra in the seismic assessment of buildings. An identification procedure is outlined, whereby an equivalent single degree of freedom (SDOF) system is devised to represent the building. The SDOF system characteristics (stiffness, strength, post‐peak force response and ductility) are readily evaluated from observation of the seismic response of buildings and simple mechanics. The characteristics are then tuned using measurements from instrumented buildings. Based on the earthquake scenario and structural response characteristics, appropriate inelastic acceleration and displacement spectra are selected and used to ‘predict’ the response. Comparison between the measured and predicted responses for the five buildings studied in the paper confirm the feasibility of the procedure and the realism of the results. Copyright © 2000 John Wiley & Sons, Ltd.     

GB/T 38591—2020《建筑抗震韧性评价标准》解读

近年来，美国和日本等国家相继提出了城市抗震韧性的概念并进行了相关研究，对建筑结构的抗震性能要求由“安全性”提升到了“韧性”的层面。我国市场监督管理总局和标准化管理委员会于2020年3月31日联合发布了GB/T 38591—2020《建筑抗震韧性评价标准》，该标准将于2021年2月1日实施。为了帮助使用者更深入地理解标准，对抗震韧性的研究现状和我国的建筑抗震性能化设计方法进行综述，对该标准的编制背景、过程，以及各章节内容进行简要介绍，对标准的关键条文进行深入解读，详细说明了建筑抗震韧性评级流程、抗震韧性评价指标以及指标的计算方法。标准中建立了本土化的构件易损性数据库，对于建筑震后修复时间提出了明确的修复路径和计算方法，使得评级的标准更清晰统一。     

Structural design of high‐rise buildings using steel‐framed modules: A case study in Hong Kong

Steel‐framed modular buildings afford certain advantages, such as rapid and high‐quality construction. However, although steel‐framed modules have been adopted in several countries, most of them are limited to low‐to‐medium‐rise structures; modular high‐rise buildings are rare. This study proposes a feasible structural design solution for high‐rise buildings using a steel‐framed modular system. A 31‐story student hostel building in Hong Kong is redesigned as a steel‐framed modular building and used as a case study. The finite element models of the building are formulated, and the structural behaviors under wind and earthquake load scenarios are compared. Moreover, the structural design process used for the 31‐story building is applied to design a hypothetical 40‐story modular building to further examine the proposed design solution. The numerical analysis results indicate that the roof lateral displacements and interstory drift ratios of the redesigned modular building are within the allowable limits of design codes; moreover, the modular connections behave elastically under the most adverse loading scenarios. Accordingly, the proposed solution can be used to design steel‐framed modular buildings of up to 40 stories, while complying with relevant wind and seismic codes.     

基于耗能差指数和SIR模型的#br# 结构易损性及可恢复能力评估

传统结构地震易损性中结构地震响应指标对损伤反映不充分,且无法为结构震后可恢复性评估提供准确的初始损伤指标。针对上述不足和结构地震可恢复能力评估的需求,提出运用基于弹塑性耗能差的损伤指数进行结构地震易损性评价的方法。建立可推演出指定地震动强度和超越概率下的损伤指数的计算方法。利用SIR模型能够描述系统损伤和恢复动态演变过程的特点,提出基于该模型的单体建筑结构和区域建筑群的性能水平恢复函数模型及结构的恢复能力计算方法,从而表征建筑结构群体在地震激励下的“直接损伤 间接损伤 恢复”全过程。以单体结构和区域结构为算例进行易损性分析和震后可恢复性评估,结果表明：基于弹塑性耗能差的损伤指数具有真实可靠和机理明确的特点,在离散性和相关性方面均优于传统指标。SIR可恢复性能评估模型较常用恢复函数模型更为精准,简单高效且适合推广到区域建筑集群体当中,是对现有区域恢复性能评估框架的有益补充。     

Computer-Aided Pre- and Post-Earthquake Assessment of Buildings Involving Database Compilation, GIS Visualization, and Mobile Data Transmission

Abstract:   The aim of this article is to present a computer-aided comprehensive strategy for the rapid visual inspection of buildings and the optimal prioritization of strengthening and remedial actions that are necessary prior to, and after, a major earthquake event, respectively. Based on the visual screening procedures used in the United States and past experience in seismic assessment of buildings in Greece and Turkey (the two countries with the highest seismic risk in Europe), a building inventory is first compiled; then a vulnerability ranking procedure that is specifically tailored to the prevailing construction practice in Southeast Europe is implemented into a multi-functional, georeferenced computer tool, that accommodates the management, evaluation, processing and archiving of the data stock gathered during the pre- and post-earthquake assessment process, and the visualization of its spatial distribution. The methodology proposed and the computer system developed is then applied to the city of Düzce, Turkey, a city strongly damaged during the devastating 1999 earthquake.     

山地小城市地震次生火灾风险等级评估

选取昆明市东川区为研究对象,以结构性危险概率、 功能性危险概率评估地震次生火灾的危险性,引入重大危险源修 正系数后,建立单体建筑震后次生火灾起火概率模型,通过Arc- GIS 平台进行图像、数据分析,评估东川城区建筑地震次生火灾 风险等级。研究表明以框架、砖混结构建筑为主的新城区、中心城 区,建筑密度低、抗震等级高,次生火灾风险低,而以砖砌、土木结 构建筑为主的老城区、边缘行政村,建筑密度大、抗震等级低,次生 火灾风险普遍较高。     

Shaking table model test and numerical analysis of a long‐span cantilevered structure

This paper presents an earthquake‐resistance study program of a long‐span cantilevered story building. The program consists of a shaking table test study and nonlinear seismic analysis using finite element modeling technique. A 1/30 scale model of the prototype structure was designed and manufactured and then tested via the shaking table facility. Dynamic responses of the prototype structure under different earthquake excitation loadings were simulated. Dynamic properties, acceleration, and deformation responses of the scale down model under different intensity levels of earthquake were studied. The dynamic behavior, cracking pattern, and the likely governing failure mechanism of the structure were analyzed and discussed as well. The seismic responses of the prototype building were deduced and analyzed in terms of the similitude law. Furthermore, elaborate finite element models were established, and nonlinear numerical analysis of the prototype structure was conducted. The errors in the seismic response of the structure caused by structural simplification of scale down modeling are found small, and the dynamic behavior of the structure was not altered in the earthquake excitations. This test study provides a benchmark to calibrate the finite element model and a tentative guide in seismic design of such long‐span cantilevered story buildings.     

Seismic response of self‐centering precast concrete frames with hysteretic dampers

With the rapid development of cities and the invasion of major natural disasters such as earthquakes, the resilience city as a new design concept has been paid more and more attention. As an important branch of self‐centering seismic resisting system, self‐centering concrete frame system has been studied by many scholars. These studies prove that self‐centering concrete frame structure has excellent self‐centering ability but poor energy dissipation capacity. Adhering to the working principle of self‐centering structure and considering the development concepts of building industrialization and modularization, this paper proposed a kind of self‐centering precast concrete frame with hysteretic damper (SCPCHD). In order to verify its energy dissipation capacity and seismic performance, elaborate finite element models were established and elastoplastic dynamic time history analyses were carried out. The results showed that the SCPCHD frame has a similar interstory displacement response to the reinforced concrete (RC) frame and the energy dissipation performance of its joint is obviously superior to the RC frame under rare earthquake because the SCPCHD frame has low damage characteristics and excellent damping device. In summary, this paper proves the feasibility and superiority of the SCPCHD frame, providing reliable support for further research.