剪力墙沿竖向截断对框架柱内力影响的探讨

根据截断剪力墙后框架-剪力墙结构的受力特点,建立含截断剪力墙的框-剪结构空间协同工作基本微分方程,给出框架楼层剪力与框架-剪力墙结构刚度特征值、剪力墙截断位置之间的关系式,并分析截断剪力墙后框架柱内力的变化情况。最后,针对某框-剪结构工程实例,利用SATWE软件,进一步分析剪力墙截断后对框架柱内力的影响。     

RC框架-剪力墙结构的框架地震层剪力分配

我国《建筑抗震设计规范》与《高层建筑混凝土结构技术规程》关于框架-剪力墙结构地震层剪力分配的规定是依据设计经验提出来的,并没有考虑框架与剪力墙各自抗侧刚度比值的影响,因而较为笼统,明显欠缺合理性。连续化分析方法中框架-剪力墙结构的刚度特征值是表征框架-剪力墙受力和变形的重要指标。本文采用静力弹塑性分析（Pushover）方法和动力弹塑性时程分析方法对刚度特征值为1.0～4.5的8栋框架-剪力墙结构进行了全过程研究,得到了多遇、基本和罕遇地震作用下不同刚度特征值的框剪结构楼层剪力分配,以及罕遇地震下剪力墙刚度退化对楼层剪力分配的影响,并给出了框架层剪力分配公式供设计参考。     

异形柱框-剪结构中剪力墙刚度变化对柱内力的影响

利用异形柱框架 剪力墙结构协同工作的基本微分方程 ,给出异形柱框架楼层剪力与框 剪结构刚度特征值的关系 ,分析在中高层异形柱框架 剪力墙结构设计中 ,改变剪力墙的弯曲刚度对异形柱框架楼层剪力的影响 ,并通过算例说明调整剪力墙数量和优化剪力墙抗侧刚度时异形柱内力 (剪力和轴力 )的变化情况。     

高层建筑框架-剪力墙结构设计

设计框架-剪力墙结构,应先根据底层结构剪力墙与框架柱面积之和与本楼层面积之比确定剪力墙数量,然后通过计算判断剪力墙布置的合理性。剪力墙的轴压比限值应与框架柱一样,通过考虑剪力墙延性、约束边缘构件配箍特征值及剪力墙高宽比等构造措施提高。连梁跨高比小,若两端连接的墙与柱刚度差异较大,易造成连梁两端变形很大而产生很大的内力,设计中可以通过连梁刚度折减和设置水平通缝解决。     

刚度特征值对框架-剪力墙结构抗震性能的影响研究

刚度特征值是影响框架-剪力墙结构受力状态和变形特征的主要参数,本文采用有限元软件SATWE对不同刚度特征值的8个框架-剪力墙结构模型进行了分析计算,研究了在地震作用下刚度特征值对框架-剪力墙结构抗震性能的影响,并给出了确定框架-剪力墙结构合理剪力墙数量的刚度特征值建议值。     

增设可恢复功能剪力墙加固框架的剪力分析

可恢复功能剪力墙可与框架形成框架-摇摆剪力墙结构或框架-自复位剪力墙结构,从而有效提升框架结构的抗震性能,避免薄弱层的出现.目前已有少量增设可恢复功能剪力墙加固既有框架结构的工程应用.为研究增设可恢复功能剪力墙加固框架的影响,首先提出了框架-可恢复功能剪力墙的分布参数模型,在此基础上使用模型对加固前后框架分担的剪力进行了对比分析.结果表明,均布外荷载作用下,在低楼层,加固后框架承受的水平剪力小于加固前框架;而在高楼层,加固后框架承受的水平剪力则大于加固前框架,该抗剪需求缺口受刚度特征值λ和Rf(反映墙体底部约束程度与剪力墙刚度相对关系的特征值)影响.     

简析剪力墙弯曲刚度变化对异形柱内力的影响

利用异形框架-剪力墙结构空间协调工作的基本微分方程给出异形柱框架楼层剪力与框架-剪力墙结构刚度特征值的关系式。通过简要介绍改变剪力墙弯曲刚度的几种方法,分析在中高层异形柱框架-剪力墙结构设计中,剪力墙弯曲刚度发生变化时异形柱框架楼层剪力变化情况。     

框架与剪力墙的刚度配置

对变刚度框架 剪力墙结构 ,提供了估定剪力墙最小刚度的方法 :1 )通过图表 ,估定底部若干楼层的剪力墙最小刚度 ;2 )采用一个结构参数作为比例常数 ,算出其余楼层的剪力墙刚度。方法简单、快速、有效。文末给出了算例 ,以供参考     

基于有限基础刚度的框架-剪力墙结构抗震设计

从框架-剪力墙结构协同工作基本微分方程入手,推导基于有限基础刚度的框架-剪力墙结构侧移刚度以及水平荷载作用下的侧移和内力计算方法。重点研究剪力墙下和框架柱下基础刚度对框架-剪力墙结构侧移刚度、最大层间相对水平位移及内力分布的影响规律,揭示现行规范对框架-剪力墙结构框架剪力调整的必要性。提出框架-剪力墙结构合适基础刚度的理念和确定方法,有利于进一步完善高层建筑抗震设计。分析结果和震害情况表明,剪力墙下基础刚度退化,框架-剪力墙结构在水平荷载作用下内力重分布显著,框架内力沿竖向分布有所增大,特别是底层框架柱剪力、弯矩急剧增大,应引起足够重视。     

考虑轴压比影响RC框架-剪力墙结构侧移刚度退化及楼层剪力重分配性能仿真分析

采用三维虚拟层合单元非线性有限元分析方法,经对一个两跨四层RC框架分析算例验证后,分别对三种轴压比RC框架和剪力墙抗侧性能进行模拟分析,分析结果表明,轴压比越大侧移刚度退化速率越快;构建三个不同刚度特征值的四层框架-剪力墙结构空间模型并进行抗侧性能仿真分析,发现进入非线性阶段后,框架分担水平剪力比例随水平荷载增大而提高,且结构刚度特征值越大提幅越多,极限荷载时分担比例提至其初始值2倍以上。分析结果还表明,现行规范关于框架-剪力墙结构框架分担楼层剪力的调整规定取值偏低。     

底部框剪配筋砌块砌体房屋弹塑性地震反应的数值模拟

在总结底部框剪砖房和配筋砌块砌体的抗震性能研究成果的基础上,对底部框剪上部配筋砌块砌体结构的抗震特性进行了初步研究。采用层间剪切模型和三折线骨架曲线恢复力模型,分别按6、7、8度区的多遇烈度、基本烈度和罕遇烈度,输入ElCentro地震波,模拟此类房屋的线性和非线性地震反应。通过分析加速度和位移地震反应,恢复力和层间位移角的变化,考察了该结构的抗震性能和抗震能力。结果表明:底部两层框剪上部六层配筋砌块砌体结构(高25.5m)可用于8度地震区,这种结构的底部框剪层是薄弱部位;应提高框剪层的水平地震剪力设计值,增强延性设计,提高抗倒塌能力。     

底部两层框架-抗震墙砖房抗震能力的分析方法与设计控制

提出了底部两层框架 -抗震墙砖房框剪层和砖混层的极限受剪承载力、侧移刚度、极限剪力系数计算公式 ,并基于设置不同数量抗震墙的底部两层框架 -抗震墙砖房的实例计算和弹塑性时程分析 ,给出了结构砖混过渡层与相邻框剪层的极限剪力系数比和侧移刚度比的合理取值及薄弱楼层位置判别和破坏状态评定的方法和原则。     

谈底部框架--抗震墙砖房的抗震概念设计

基于底部框架—抗震墙砖房的结构特点 ,结合GB 5 0 0 11 2 0 0 1建筑抗震设计规范 ,提出了底部框架层、过渡层、上部砌体结构等结构体系的抗震设计要点 ,从而提高了房屋的整体抗震性能     

底层框架-抗震墙砖房的抗震性能

探讨了决定底层框架-抗震墙砖房抗震性能的几个问题,主要有:底层的钢筋砼框架-抗震墙体系应合理设置,底层钢筋砼墙宜为带边框开竖缝的低矮墙,过渡楼层的抗剪和抗弯能力应给予增强和底层与上部砖房的抗震能力宜相匹配等.     

Coupled‐two‐beam discrete model for dynamic analysis of tall buildings with tuned mass dampers including soil–structure interaction

An equivalent coupled‐two‐beam discrete model is developed for time‐domain dynamic analysis of high‐rise buildings with flexible base and carrying any number of tuned mass dampers (TMDs). The equivalent model consists of a flexural cantilever beam and a shear cantilever beam connected in parallel by a finite number of axially rigid members that allows the consideration of intermediate modes of lateral deformation. The equivalent model is applied to a shear wall–frame building located in the Valley of Mexico, where the effects of soil–structure interaction (SSI) are important. The effects of SSI and TMDs on the dynamic properties of the shear wall–frame building are shown considering four types of soil (hard rock, dense soil, stiff soil, and soft soil) and two passive damping systems: a single TMD on its top (1‐TMD) and five uniformly distributed TMDs (5‐TMD). The results showed a great effectiveness of the TMDs to reduce the lateral seismic response and along‐wind response of the shear wall–frame building for all types of soils. Generally speaking, the dynamic response increases as the flexibility of the foundation increases.     

Dynamic shear force amplification in regular frame–wall systems

A parametric study is conducted to investigate the dynamic shear amplification factor (DAF) in low‐to‐mid‐rise frame–wall systems in which the reinforcement curtailment along the height matches the required code strength. The level of frame–wall interaction is varied by changing the wall index, defined as the ratio of the total wall area to the floor plan area, in a generic frame–wall system, and its correlation with the DAF is investigated. Wall index values ranging in the 0.2% to 2% interval are selected. Walls with lengths of 3m , 5 m and 8 m are used in the design of model buildings of 4, 8 and 12 stories. Shear–flexure beam continuum formulation is used in design and modeling. The global behavior is analyzed using nonlinear response history procedure using spectrum compatible ground motions. It is found that the primary source of amplification is the level of inelastic demand on the system. Walls designed for code‐specified force reduction factor R = 6 experienced an average base shear force amplification in the order of 1.64 with standard deviation of 0.19 with respect to design shear force. Amplification diminishes with decreasing R. An expression for the dynamic amplification factor as a function of the number of stories and force reduction factor R is proposed. Copyright © 2015 John Wiley & Sons, Ltd.     

底部框剪砌体房屋抗震性能的试验研究

对底部两层框架—砖抗震墙、上部三层砖房 ,底层框架—砖抗震墙、上部四层砖房及底部两层框架—混凝土抗震墙、上部五层砖房 (三榀 ) 1 6比例模型进行了模拟地震振动台试验 ;分析了结构在水平地震作用下的力学性能 ,包括受力特点、变形特征、破坏形态等 ,以及结构在不同受力阶段的动力特性变化规律、地震反应分布规律 ,结构的抗震能力、薄弱层和薄弱部位 ;提出了结构弹塑性动力分析的力学模型和方法 ,尤其框剪层和砖砌体层的恢复力特性计算模型及其特征点的计算公式 ;最后对三种房屋的模型和原型结构进行了弹塑性地震反应分析 ,并在与试验结果对比的基础上 ,提出了抗震设计建议 ,为底部框剪上部砌体房屋的抗震设计与动力分析提供了依据与方法。     

Seismic design of flexible-stiff mixed frame with energy concentration

Structural frames described as having energy concentration are those in which inelastic energy absorption is limited to specified stories, with the other parts of the frame remaining elastic. It has already been shown that the seismic response of a frame with energy concentration in its first story can be easily predicted, provided the energy-absorbing stories consist of both flexible and stiff elements. The present paper derives a general method for predicting seismic response of a flexible-stiff mixed frame with energy concentration in arbitrary stories. This method applies generally to the flexible-stiff mixed frame with energy concentration, both in cases where the energy-absorbing element is a viscous damper, and in those where it is a hysteretic damper.     

Story strength demands of irregular frame buildings under strong earthquakes

Irregular frame buildings with discontinuous columns in one or several stories have been vulnerable to collapses during strong earthquakes. This paper presents the investigation of the seismic response demands at irregular stories of such buildings in terms of story strength factor demand. In this study, a story strength factor was defined to represent the relative reserve strength against the formation of a story failure mechanism of the structure. In addition, a huge number of rigorous nonlinear inelastic dynamic time‐history analyses of various analytical models of 7‐story, 8‐story and 15‐story frame structures with discontinuous columns in one and two irregular stories were conducted under 29 strong earthquake records with various characteristics. The results show that the seismic response demands at irregular stories of the structures were well evaluated in terms of the story strength factor demand to avoid development of a story failure mechanism of the structures when subject to strong earthquakes. Copyright © 2011 John Wiley & Sons, Ltd.     

山地掉层框架-摇摆墙结构抗震性能研究

竖向刚度不均匀是山地掉层框架结构的突出特点,其在地震作用下的动力反应特性与普通框架结构存在较大的差异,山地掉层框架结构在地震中易在上接地层出现层屈服破坏机制。为改善该类结构的抗震性能,在山地掉层框架结构外部附加底部铰接、具有一定转动能力的摇摆墙,形成山地掉层框架-摇摆墙结构体系。对3个总层数为七层的掉不同层不同跨的山地掉层框架摇摆墙结构进行动力弹塑性分析结果表明,附加摇摆墙的山地掉层框架结构的基本周期较原结构的相差不大。摇摆墙设置在不同位置的山地掉层框架摇摆墙结构动力反应特性不同。摇摆墙的加入能够均匀结构各层层间变形,有效改善山地掉层框架结构的抗震性能,可避免原薄弱层上接地层的破坏集中现象,实现了整体耗能机制。