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根据高层建筑的不同结构类型讨论了高层建筑震害预测方法,分析了东营市城区高层建筑在Ⅵ-Ⅹ度下抗御震害的能力。东营市城区高层建筑普遍具有抗御Ⅷ度地震作用的能力,在Ⅸ度地震作用下,各建筑仍具有一定的延性,不致被毁坏。框架结构高层建筑的抗震能力相对较弱,在Ⅷ度地震作用下即发生中等破坏,剪力墙和框架一剪力墙结构的高层建筑在本地区设防烈度(Ⅶ度)的地震作用下至多发生轻微破坏,呈现出良好的抗震能力。 相似文献
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《地震工程与工程振动》2020,(4)
震害表明结构反应修正系数的子项冗余度系数取为1,过高地估计了结构通过备用荷载路径进行内力重分布的抗竖向连续倒塌能力。本文拟分别采用静力Pushdown和动力竖向IDA方法对根据《建筑抗震设计规范》GB50011-2010(2016版)设计的RC框架进行分析,采用损伤强度比DSR作为冗余度系数,并根据倒塌临界值,判定结构在设计荷载作用下是否具有足够的抗倒塌能力。分析结果表明,按VII、VIII度设防设计的结构,冗余度系数均大于1,结构在设计荷载作用下不会发生连续倒塌,但是按VI度设防设计的低层结构冗余度系数小于1,在设计荷载作用下结构会发生连续倒塌。针对VI度设防设计的结构,采用实际的冗余度系数最小值0.69,对结构反应修正系数值进行修正,修正后的数值为2.02。实现在结构地震影响系数曲线中考虑抗连续倒塌能力的影响,修正后的地震影响系数为现行抗震规范中相应取值的1.45倍,提高了结构设计地震力,防止结构发生连续倒塌。 相似文献
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近地空中爆炸作用下钢框架结构冲击响应 总被引：2，自引：0，他引：2
采用多物质欧拉与拉格朗日耦合算法,对框架结构和混凝土地面采用Lagrange单元、空气和炸药采用多物质ALE单元,建立流固耦合有限元模型,对一个五层的钢框架结构在近地爆炸作用下冲击压力波的传播过程、结构冲击响应和变形以及破坏过程进行了数值模拟.数值模拟分析结果表明,拉格朗日-欧拉耦合算法较好地模拟了爆炸冲击波在介质中的传播和作用在结构上的爆炸荷载效应.在爆炸近区,空气爆炸冲击波的衰减速率快;爆炸产生强烈的冲击波首先使钢框架结构正面的柱和梁柱节点区产生很大的塑性变形,钢框架柱在发生爆炸的瞬间失去承载能力,最终导致建筑物整体倒塌.考虑结构变形和流体荷载间的相互影响可以较真实地模拟结构在爆炸荷载作用下的连续倒塌过程,为研究结构在爆炸荷载作用下的连续倒塌提供了有效手段. 相似文献
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《地震工程与工程振动》2021,41(3)
为研究不同底部层高的钢筋混凝土框架结构的易损性,应用SAP2000软件,采用动力增量分析法分别对设防烈度为7度和8度区6个不同底部层高的框架结构在地震作用下进行了非线性时程分析,得到了地震易损性曲线和结构在极限状态下的地震动强度指标,经回归拟合得到了不同设防烈度区的结构的失效概率公式和结构倒塌储备系数(CMR)。研究表明:结构在弹性阶段的耗能能力较差,在弹塑性阶段表现出较好的延性耗能能力。同一抗震设防烈度的RC框架结构倒塌储备系数CMR随着底部层高的提高而线性降低,底部层高较高框架结构的抗地震倒塌能力与底层层高负相关,基于IDA方法得到了不同底部层高RC框架结构的失效概率计算公式和抗倒塌储备系数线性拟合公式,可供工程设计参考。 相似文献
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选取我国现代农村地区较有代表性的砖混结构农居作为研究对象,计算了砖混结构农居在不同抗震设防标准下的造价,得出：相对于不设防的情况,抗震烈度为Ⅵ度时单方造价提高大约17%;从Ⅵ度设防提高到Ⅶ度单方造价增加大约9％;从Ⅶ度设防提高到Ⅷ度,单方造价增加大约11％。分析发现引起砖混结构农居造价变化的主要原因是材料费,对造价的影响率达65%左右,其中又以钢筋和混凝土增加的费用影响最大。因此将砖混结构农居从不设防提高到更高的设防标准单靠农民自身的能力是不行的,政府必须给予适当的财政支持。 相似文献
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本文按现行规范及技术规程设计了设防烈度为8度的一个规则的钢筋混凝土异形柱框架,并进行了单向水平地震作用下的空间三维非线性地震反应分析,考查了异形柱框架结构在设防和罕遇地震水准下的整体抗震性能,对结构能否达到抗震设防目标进行了初步评价。结果表明,8度区按规范设计的结构在设防烈度及罕遇烈度地震作用下基本能够达到预期的抗震设防目标。 相似文献
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根据汶川地震各烈度区内变电站破坏状况、停运状况以及恢复时间的统计,分析了不同烈度区变电站地震破坏和功能失效特点和模式,定义了变电站震害指数,得出了设防烈度为Ⅶ度的变电站地震破坏和功能失效的震害指数与烈度的Di-Ⅰ关系曲线,并结合我国电力设施抗震设计标准,外推了设防烈度Ⅵ、Ⅷ、Ⅸ度变电站的Di-Ⅰ曲线,由此建立了基于抗震设防烈度和震害统计的变电站震害快速评估方法(FI-EDS法).通过德阳地区49个110kV及以上变电站的震害实例,对评估方法进行检验,结果表明,用本文方法快速评估得出的变电站破坏等级,0级偏差比率为47％,±1级偏差比率为45％,±2级偏差比率为8％.本文评估方法具有可接受的精度,并且可操作性强. 相似文献
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借助非线性动力时程分析，对严格按照规范Ⅶ、Ⅷ、Ⅸ度设计的5个三跨6层钢筋混凝土框架结构开展易损性分析，建立了基于峰值加速度的易损性曲线。从易损性的角度对不同设防标准RC框架结构的抗震性能做了定量评价，并探讨了设防标准对RC框架结构易损性的影响。分析表明，对应于设防小震、中震及大震水平的峰值加速度，结构“小震不坏”、“中震可修”和“大震不倒”的失效概率均在18%以内，可认为结构满足三水准的性态控制目标。随着结构设防标准的提高，其易损性随之降低，相同峰值加速度对应的各个破坏状态的超越概率均有所降低。此外，将框架结构的设防烈度提高1度，其“大震不倒”的失效概率会明显减小。而将框架结构的设防烈度降低1度，其“大震不倒”的失效概率会显著增加，最高可达4倍。 相似文献
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Earthquake-induced building collapse and progressive collapse due to accidental local failure of vertical components are the two most common failure modes of reinforced concrete (RC) frame structures. Conventional design methods usually focus on the design requirements of a specific hazard but neglect the interactions between different designs. For example, the progressive collapse design of an RC frame often yields increased reinforcement and flexural strength of the beams. As a result, the seismic design principle of “strong-column-weak-beam” may be violated, which may lead to unfavorable failure modes and weaken the seismic performance. To avoid these adverse effects of the progressive collapse design on the seismic resistance of RC frames, a novel structural detailing is proposed in this study. The proposed detailing technique intends to concurrently improve the seismic and progressive collapse performances of an RC frame by changing the layout of the newly added longitudinal reinforcement against progressive collapse without introducing any additional reinforcement. A six-story RC frame is used as the prototype building for this investigation. Both cyclic and progressive collapse tests are conducted to validate the performance of the proposed structural detailing. Based on the experimental results, detailed finite element (FE) models of the RC frame with different reinforcement layouts are established. The seismic and progressive collapse resistances of different models are compared based on the incremental dynamic analysis (IDA) and nonlinear dynamic alternate path (AP) methods, respectively. The results indicate that the proposed structural detailing can effectively resolve the conflict between the seismic and progressive collapse designs. 相似文献
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我国7度设防等跨RC框架抗地震倒塌能力研究 总被引：1，自引：0，他引：1
我国建筑结构抗震设计主要采用基于小震下的构件承载力计算保证结构的抗震承载能力,配合抗震构造措施保证结构的变形能力,缺乏大震抗倒塌定量计算.而实际地震震害表明,即使是同类结构,其结构体系参数对其抗地震倒塌能力也有很大影响.为此,本文依据《建筑抗震设计规范》GB50011 - 2001,按照7度抗震设防设计了24个不同跨度... 相似文献
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Design objectives and collapse prevention for building structures in mega-earthquake 总被引：2，自引：2，他引：0
A "mega-earthquake" is one with an intensity larger than the most severe earthquake intensity category currently considered in design codes. For a "mega-earthquake," the design objective of a given structure is to "preserve living spaces for people in the buildings." In this paper,factors that may influence the collapse resistance of RC frames in a mega-earthquake are analyzed based on seismic damage observed in the 2008 Wenchuan earthquake. Methodologies to improve structural collapse resistance focus on three aspects:global strength margin,global redundancy and global integration of the structural system. Fundamental principles and design concepts for collapse prevention under a mega-earthquake are proposed,and issues that need further research are identified. 相似文献
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Seismic performance and probabilistic collapse resistance assessment of steel moment resisting frames with fluid viscous dampers 总被引：1，自引：0，他引：1 
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下载免费PDF全文 Choung‐Yeol Seo Theodore L. Karavasilis James M. Ricles Richard Sause 《地震工程与结构动力学》2014,43(14):2135-2154
This paper evaluates the seismic resistance of steel moment resisting frames (MRFs) with supplemental fluid viscous dampers against collapse. A simplified design procedure is used to design four different steel MRFs with fluid viscous dampers where the strength of the steel MRF and supplemental damping are varied. The combined systems are designed to achieve performance that is similar to or higher than that of conventional steel MRFs designed according to current seismic design codes. Based on the results of nonlinear time history analyses and incremental dynamic analyses, statistics of structural and non‐structural response as well as probabilities of collapse of the steel MRFs with dampers are determined and compared with those of conventional steel MRFs. The analytical frame models used in this study are reliably capable to simulate global frame collapse by considering full geometric nonlinearities as well as the cyclic strength and stiffness deterioration in the plastic hinge regions of structural steel members. The results show that, with the aid of supplemental damping, the performance of a steel MRF with reduced design base shear can be improved and become similar to that of a conventional steel MRF with full design base shear. Incremental dynamic analyses show that supplemental damping reduces the probability of collapse of a steel MRF with a given strength. However, the paper highlights that a design base shear equal to 75% of the minimum design base shear along with supplemental damping to control story drift at 2% (i.e., design drift of a conventional steel MRF) would not guarantee a higher collapse resistance than that of a conventional MRF. At 75% design base shear, a tighter design drift (e.g., 1.5% as shown in this study) is needed to guarantee a higher collapse resistance than that of a conventional MRF. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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本文主要研究如何通过合理设计来提高高层钢结构的整体抗震能力。首先,给出了高层钢结构的非线性计算模型;其次,建立了高层钢结构在强地震动作用下的倒塌失效模式的极限状态判别准则;然后,通过模态pushover分析,研究了高层钢结构在水平地震作用下的损伤规律;最后,重点研究了高层钢结构的整体抗震能力的提高方法,提出了均匀损伤的设计方法,该方法通过消除结构的薄弱层,来达到提高高层钢结构的整体抗震能力的目的。通过对两栋20层的高层钢框架结构进行极限时程分析和极限pushover分析,验证了文中提出的均匀损伤的设计方法的可行性。本文的工作可为高层钢结构的抗地震倒塌设计提供参考依据。 相似文献
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阻尼器连接填充墙采用黏滞阻尼器与主体框架结构连接,是一种新型填充墙与框架的柔性连接方式,能满足柔性框架结构的大变形需求。为使得阻尼器连接填充墙达到最优的力学性能,结构布置和构件力学参数的选择十分重要,采用有限元软件ABAQUS分别建立了柔性钢框架结构和阻尼器连接填充墙-框架结构的有限元模型,考察不同阻尼系数阻尼器连接填充墙的抗风、抗震和抗倒塌力学行为。数值模拟结果表明,经过对阻尼器阻尼系数优化取值后,阻尼器连接填充墙在风荷载作用下不会开裂且最大应力值仅为嵌砌刚性连接填充墙的1/3,主体结构加速度地震响应可降低48%左右,并能保证墙体在罕遇地震作用下不倒塌。最后给出阻尼器连接填充墙设计流程。 相似文献
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Seismic hybrid simulation of a nonductile RC building with severe damage to multiple columns 下载免费PDF全文
下载免费PDF全文 Reinforced concrete frame structures built prior to the mid‐1970s are susceptible to brittle column failure under seismic action, potentially leading to progressive collapse of the structure. The behavior of columns susceptible to brittle shear‐axial failure has been studied previously but rarely has the interaction between damaged columns and the surrounding three‐dimensional structure been investigated experimentally and at full scale. In this study, as the second in a series of hybrid simulations, two full‐scale reinforced concrete columns of a representative pre‐1970s structure were tested at the Multi‐axial Full‐scale Substructure Testing and Simulation (MUST‐SIM) laboratory. Through the use of hybrid simulation, the interaction of the columns with the surrounding structure is studied under a severe seismic motion including vertical excitation. The computational model representing the remainder of the representative 10‐story structure is created in the computer program OpenSees. During the hybrid simulation, both physical specimens experience significant loss of shear and axial strength, and the effects of these failures on the surrounding system are described. The three‐dimensional computational model in OpenSees allowed for analytical flexural‐axial failure of a third column in the structure to occur. The effects of these multiple failures on the response of a full structural system under seismic action are quantified, and the progressive collapse resistance mechanisms are discussed. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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近年来，随着经济、技术的进步以及抗震意识的加强，建筑结构加固也飞速发展。在地震多发的农村地区，为了提高建筑结构的抗震性能，但同时又缺乏一定的经济基础和理论知识支撑，导致很多简单粗糙的支撑建筑结构的措施出现，这些支撑方案大多缺乏科学的设计与评估。本文针对这一现象，以某典型的非正规设计的3层2跨框架结构为例，分析评价支撑边框和支撑中框对该框架结构地震作用下抗倒塌性能的影响。通过增量动力分析（IDA）计算方法，结合结构易损性方程评估结构的抗倒塌能力，计算结果表明支撑中框和支撑边框能够将非正规结构在罕遇地震作用下的倒塌概率从17.5%降至2.4%和6%。在此基础上，进一步分析了2种支撑位置对结构在3个典型地震强度作用下对结构响应的影响。结果表明，支撑框架结构中框对结构抗倒塌能力的提升和抗震性能的保证效果比支撑边框更好，在条件允许的情况下，应优先考虑支撑中框。 相似文献
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为了提取天然地震和爆破或塌方记录波形在震源深度、震源尺度、震源破裂机制、地震波传播途径、地震波衰减等方面的差异特征信息,本对山东数字化台网记录的天然地震和爆破或塌方波形进行了小波多分辨率的能量线性度特征分析,提出了用小波变换能量线性度方法识别天然地震与爆破或塌方事件．结果表明：在精细结构小波分解信号“能量”线性度方面,天然地震主要集中在-2．0～1．0之间,爆破或塌方主要集中在2．0～3．4之间;在精细结构小波分解信号“能量”最大值对应的小波分解尺度方面,爆破或塌方主要集中在4～5,频段集中在0．7～3．1Hz之间,而天然地震主要集中在1～2,频段集中在6．25～25Hz之间． 相似文献