水平地震作用下不对称不规则结构抗扭设计方法研究

对水平地震作用下不对称不规则结构的抗扭设计进行了详细分析与研究。结果表明,设计这类结构时应主要考虑:由楼板(刚性隔板)的扭转角引起的竖向构件的扭转不超过许可值;边端框架或剪力墙的层间位移角应小于规范限值;控制不同烈度地震作用下的楼板平面内应力在许可范围内。从楼层扭转位移比的定义,楼层扭转角与楼层质心距端部框架或剪力墙距离之积,可以看出现行抗震规范仅采用扭转位移比来控制楼层的扭转是不够的。     

关于框架加少量剪力墙结构抗震设计的探讨

一、问题的提出新规范实施以来 ,在施工图审查工作中 ,经常遇到框架结构布置少量剪力墙的情况 ,原因是有些结构按纯框架进行抗震计算时其层间位移角不能满足 1/ 550的限值要求[1 ,2 ] ;也有些纯框架在抗震计算时 ,抗扭指标不满足要求 ,或是扭转位移比 (楼层竖向构件最大弹性水平位移与楼层两端弹性水平位移的比值和最大层间位移与层间平均位移值的比值 )超过了 1 5的限值[1 ,2 ] ,或是扭转周期比 (结构扭转为主的第一自振周期Tt 与平动为主的第一自振周期T1 之比 )超过了0 9的限值[2 ] ,而这种结构在刚度相对较弱的一侧加了少量剪力墙后也…     

荷载相关的结构刚度中心概念及算法

通过研究给定的立面分布荷载在建筑结构楼面上的作用点位置对结构反应的影响,提出了荷载相关的结构刚度中心概念,荷载相关刚心同时依赖于结构的刚度性质和荷载分布。为了全面衡量结构的变形和内力反应,选取结构的总应变能作为扭转反应的量化指标,通过结构总应变能的极小化导出了荷载相关刚心的计算式。算例表明：当沿立面分布的水平荷载的作用位置由“传统刚心”移动到与其对应的“荷载相关刚心”上时,结构的扭转变形将明显减小,故结构中各楼层质心与其荷载相关刚心之间的偏心距可作为衡量地震作用下结构抗扭布局合理性的有效指标,并可用于指导结构的抗震设计。     

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。     

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。     

大底盘双塔偏置超限高层抗震设计

介绍了高层板楼偏心布置的超大底盘双塔商业综合体复杂高层的结构设计,分析了结构抗震超限情况并给出了相应的应对措施。此类结构存在扭转效应明显和刚度突变的特点,应加大裙房外围框架和塔楼四周环形框架抗扭刚度,减少扭转效应。应分别验算单塔模型和多塔模型,与扭转有关的计算结果应采用多塔模型。塔楼底部和裙房收进位置上下层的竖向构件是可能的薄弱部位,设计时底部加强区取一层到裙房上两层,加强区竖向构件按中震弹性设计。裙房顶层存在刚度突变,受力和变形情况较为复杂,板厚和配筋应加强,防止楼板开裂。     

中高层异形柱框-剪结构的剪力墙抗侧移刚度优化分析

综合考虑剪力墙的剪切变形、异形框架柱的轴向变形和连梁刚度对异形柱框一剪结构的抗侧移刚度的影响，利用框-剪结构空间协同分析的连续-离散化方法，以楼层划分单元推导单元的内力、位移关系式，同时采用振型分解反应谱法计算水平地震作用，并考虑层间位移约束条件及刚重比、剪重比等构造要求，建立了中高层钢筋混凝土刚接异形柱框-剪结构的剪力墙抗侧移刚度优化数学模型。工程算例结果表明。本优化模型可行、有效，而且当剪力墙的抗侧移刚度沿结构高度发生变化时，仍可对其进行优化分析。     

考虑两侧边约束作用钢板剪力墙剪压弹性屈曲分析

目前钢板剪力墙抗剪设计中假定周边框架为钢板剪力墙提供简支约束,再通过乘以1.23的嵌固系数来考虑周边框架的约束作用,而不考虑周边框架刚度的影响。通过对剪力和单向压力组合作用下钢板剪力墙的弹性屈曲性能的有限元分析表明,两侧边构件扭转刚度与钢板剪力墙弯曲刚度的比值η可以准确地衡量两侧边构件（加劲肋）对钢板剪力墙的约束程度。...     

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。     

工字梁腹板和钢板剪力墙剪切屈曲系数分析

目前工字梁腹板和钢板剪力墙抗剪设计中分别假定翼缘和周边框架为钢板提供简支约束,再通过乘以1.23的嵌固系数来考虑周边构件的约束作用,而不考虑翼缘或周边框架的刚度。本文对剪切荷载作用下工字梁腹板和钢板剪力墙的弹性屈曲进行了有限元分析,指出与周边构件扭转刚度和钢板弯曲刚度的比值有关的参数β可以准确地衡量周边构件对钢板的约束程度。在对1000多个模型计算结果分析的基础上,给出了工字梁腹板和钢板剪力墙剪切屈曲系数随参数β的变化规律。     

框架-核心筒结构中构件截面面积的合理分配

以40层超高层建筑为例,在保持材料用量基本不变的前提下,分别采用不均匀布置和均匀布置2种方案,采用通用有限元软件 MIDAS,对比分析了结构自振周期、扭转效应、抗侧刚度、结构侧移、层剪力、总框架承担的剪力、框架承担总剪力百分比、底层框架承担总倾覆弯矩百分比。结果表明,只要对杆件截面面积进行合理分配,既可加快框架-核心筒结构的施工速度,又可改善结构的受力性能。     

框支剪力墙结构体系的简化抗震分析

本文把框支剪力墙结构体系的首层部分,作为耦联的弯剪弹簧支座,假定楼板在平面内的刚度为无限大,在此基础上提出了框支剪力墙结构体系的静力计算方法。并按耦联弹簧支座上的弯剪杆,提出框支剪力墙自由振动和抗震分析的简化计算方法。     

冷弯薄壁型钢住宅结构整体扭转效应分析

为了研究冷弯薄壁型钢住宅结构平面质量中心、楼层形心与刚度中心偏差较大时,结构整体扭转效应的不利影响,将楼层平面内水平荷载(风、地震)作用下结构位移分解为平动和转动2种状态,得到相应状态下各组合墙体所承担的剪力,然后将其效应进行叠加,推导出了结构的线弹性层间扭转角及组合墙体剪力和侧移变形计算公式.对某冷弯薄壁型钢多层住宅结构在水平荷载作用下的层间扭转效应进行了简化计算,并运用ANSYS进行了数值模拟分析.结果表明:水平扭转效应对该类结构影响显著,简化计算公式和有限元程序数值模拟所得结果具有较好的一致性,简化计算公式可供实际工程中对该类结构整体扭转效应的计算分析时参考.     

安信宾馆结构抗扭及抗侧移设计

安信宾馆是上海安信商业广场中的一个大型集休闲、娱乐、餐饮和酒店于一体的复杂高层建筑。建筑物平面呈椭圆形,其两端抗扭刚度和抗侧移刚度相对薄弱,结构的抗扭转设计和两端抗侧移设计成为了本工程结构设计的重点和难点。在结构的两端设置剪力墙,并设置梁式转换层实行局部转换,改善结构的抗扭性能;把结构两端柱设计为型钢混凝土柱,改善结构局部抗侧移能力,使之满足结构设计的要求。     

Torsional analysis of multi‐storey building structures under horizontal load

New closed‐form formulae are presented for the torsional analysis of asymmetrical multi‐storey buildings braced by moment‐resisting (and/or braced) frames, (coupled) shear walls and cores. The analysis is based on an analogy between the bending and torsion of structural systems. A closed‐form solution is presented for the rotation of the building. The torsional behaviour is defined by three distinctive phenomena: warping torsion, Saint‐Venant torsion and the interaction between the two basic modes. Accordingly, the formula for the maximum rotation of the building consists of three parts: the warping rotation is characterized by the warping stiffness of the bracing system, St Venant rotation is associated with the St Venant stiffness of the building and the third part is responsible for the interaction. It is demonstrated that the interaction between the warping and St Venant modes is always beneficial, as it reduces the rotation of the structure. It is shown how the proposed formula for torsion can be used for the determination of the maximum deflection of multi‐storey asymmetrical building structures. The results of a comprehensive accuracy analysis demonstrate the validity of the method. A worked example is given to show the ease of use of the procedure. Copyright © 2010 John Wiley & Sons, Ltd.     

Finite element modeling and parametric analysis of timber–steel hybrid structures

This paper presents finite element modeling and a parametric analysis of prototype timber–steel hybrid structures, which are composed of steel moment‐resisting frames and infill wood‐frame shear walls. A user‐defined element was developed to model the behavior of the infill wood shear walls based on the concept of pseudo‐nail model. The element was implemented as a subroutine in a finite element software package abaqus . The model was verified by reversed cyclic test results and further used in a parametric analysis to investigate the lateral performance of timber–steel hybrid shear walls with various structural configurations. The results showed that the infill wall was quite effective within small drift ratios, and the elastic lateral stiffness of the hybrid shear wall increased when a stronger infill wall was used. In order to ensure the structural efficiency of the hybrid shear wall system, it is beneficial to use relatively strong timber–steel bolted connections to make sure the shear force can be transferred effectively between the steel frame and the infill wall. Copyright © 2013 John Wiley & Sons, Ltd.     

加劲与不加劲钢板剪力墙的试验研究和理论分析

带或不带加劲肋的钢板剪力墙系统主要用于抵抗水平荷载,尤其是地震作用。现有文献对不带加劲肋的钢板剪力墙进行了大量的理论分析和试验研究,并提出了多种适用于超薄钢板剪力墙的分析方法,但对带加劲肋的钢板剪力墙研究较少。对2个带和不带加劲肋的单肢钢板剪力墙和其中的1榀外框架进行试验。结果表明,加劲肋提高了钢板剪力墙的性能,使钢板的能量耗散能力增加26%、剪切刚度增加51.1%,而对钢板的剪切强度影响甚微。此外,利用试验结果验证剪力墙-框架相互作用理论(PFI)的可行性。试验结果表明,该理论能够用于预测带或不带加劲钢板剪力墙剪切时的荷载-位移曲线。     

Experimental and theoretical studies of steel shear walls with and without stiffeners

Steel plate shear walls are lateral load resisting systems, especially against earthquake excitation. They are constructed with or without stiffeners. In contrary to stiffened steel plate shear walls, there are many theoretical and experimental studies on these systems without stiffeners and different analytical methods have been presented for them which are mostly applicable to very thin steel plates shear walls. In this research, two one story similar steel plate shear walls with and without stiffeners and one of their surrounding frames were tested and the behavior of them was studied. The results showed that, installation of stiffeners improved the behavior of the steel plate shear walls. It caused 26% increase in energy dissipation capacity and 51.1% increase in the shear stiffness of steel plate while its effect on the steel plate shear strength was minor. In addition, the Plate-Frame interaction theory (PFI) was verified by using the experimental results and the test results showed that, this theory has good capability for predicting the shear load – displacement curve behavior of steel shear walls with or without stiffeners.     

方钢管混凝土框架-十字加劲薄钢板剪力墙抗震性能试验研究

对3个单跨两层1∶3比例的方钢管混凝土框架-薄钢板剪力墙试件进行了低周反复荷载试验,研究了十字加劲薄钢板剪力墙的抗震性能,并与方钢管混凝土框架-非加劲薄钢板剪力墙比较。对比了框架梁柱内隔板式节点与穿芯高强螺栓-端板节点对结构性能的影响。得到了方钢管混凝土框架-薄钢板剪力墙的破坏形态、荷载-位移滞回曲线、骨架曲线、特征荷载和位移及抗震性能指标等,分析了结构的破坏特征、延性、耗能能力、承载能力及刚度退化等力学性能。结果表明,方钢管混凝土框架-薄钢板剪力墙具有良好的抗震性能;十字加劲肋限制了薄钢板剪力墙的面外变形,提高了其承载力与耗能能力,但对整体刚度影响较小;穿芯高强螺栓-端板节点提高了结构的承载力与刚度。     

Simplified analysis of asymmetric high‐rise structures with cores

A simplified elastic hand‐method of analysis for asymmetric multi‐bent structures with cores subjected to horizontal loading is presented. The structures may consist of combinations of framed structures such as coupled walls, rigid frames and braced frames with planar and non‐planar shear walls. Results for structures that are uniform with height compare closely with results from stiffness matrix analyses. The method is developed from coupled‐wall deflection theory which is expressed in non‐dimensional structural parameters. It accounts for bending deformations in all individual members, axial deformations in the vertical members as well as torsion and warping in nonplanar walls. A closed solution of coupled differential equations for deflection and rotation gives the deflected shape along the height of the building from which all internal forces can be obtained. The proposed method of analysis offers a relatively simple and rapid means of comparing the deformations and internal forces of different stability systems for a proposed tall building in the preliminary stages of the design. The derivation of equations for analysis shown in this paper are for unisymmetric stability systems only, but the method is also applicable to general asymmetric structures with cores. Copyright © 2002 John Wiley & Sons, Ltd.