【作者】 陈盈；

【导师】 石志飞；

【作者基本信息】 北京交通大学 ， 结构工程， 2009， 博士

【摘要】 框架-剪力墙结构和框架-简体结构是高层建筑结构体系中使用较多的结构形式。这种结构体系中经常会出现钢筋混凝土框架梁一端支撑于框架柱上,而另一端则与其平面外的剪力墙(或核心筒)相交,也就是剪力墙成为框架梁的另一个支座的情况。较之平面内梁-墙连接节点,这种平面外梁-墙连接节点的受力更加复杂,且尚未形成成熟的设计理论,国内外对这种节点均缺乏系统的研究。对多数设计人员而言,在目前的工程实践中一般不验算剪力墙平面外的刚度和承载力,将这种节点视为完全铰接进行设计。但在实际工程中,铰接节点构造复杂,难于实现;并且这种设计方法低估了结构体系的整体刚度,还会因忽略梁端弯矩而造成梁端及梁端墙体过早开裂。相关《规程》建议可以采取在墙中设置暗柱的措施减小梁端部弯矩对墙的不利影响,但并没有给出具体的设计方法。本文对框架梁.薄墙平面外连接节点进行了研究,并针对在剪力墙中设置暗柱的增强措施进行深入分析。主要内容包括:1.将框架梁-薄墙平面外连接节点在梁自由端受横向力作用的问题转化为剪力墙在节点处受平面外弯矩作用的受弯问题,利用弹性薄板理论,求得了包括墙体应力和内力、节点转动刚度、墙体应变能等的解析解。2.在“等效框架模型”的基础上提出剪力墙平面外“等效受弯宽度”的概念,利用转动刚度等效和应变能等效两种等效原则,给出了等效受弯宽度的确定方法。并就模型的几何参数、剪力墙配筋率、不同的墙体边界约束条件以及节点域刚化效应等进行了参数讨论,给出了等效受弯宽度的简化计算公式。3.针对4个暗柱宽度取值不同的梁-薄墙平面外连接节点的试件进行梁端循环荷载作用下的模型试验,分析了这种强梁弱墙型节点的受力机制、破坏形式、滞回特性、延性和耗能能力;并结合弹塑性数值分析结果,明确了梁墙刚度比(即暗柱宽度变化)对这种节点抗震性能的影响;给出了确定合理暗柱宽度的方法,定义此暗柱宽度为剪力墙的“有效受弯宽度”。4.针对剪力墙两种不同的破坏形式(弯曲破坏和剪切破坏),分别给出了其平面外极限承载力的计算公式,并与试验数据进行了对比。5.给出梁-薄墙平面外连接节点的设计建议(暗柱的设置)和相应的构造措施。更多还原

【Abstract】 Frame-shear wall structures and frame-corewall structures are the most commonly used in tall building structures.In such structural forms,many joints are formed by a frame-beam connected to shear-wall in its out-of-plane direction. Compared with the coplanar beam-wall joint,stress distribution in this kinds of non-planar joints is more complicated.However,very few studies on non-planar joints have been conducted.The method for detailed design of non- planar joints is still not established up to now.Owing to the assumption that the non-planar beam-wall joints act like hinges,the non-planar coupling beams are often designed as simply supported beams and the possible out-of-plane bending of the walls is ignored during reinforcement detailing. Actually,it is very difficult to construct an ideal hinge between a concrete shear wall and a beam.While treating the non-planar joints as hinges would tend to underestimate the lateral stiffness and strength of the structural system,neglect of possible bending of the beams and walls near the joints in reinforcement detailing may lead to serious cracking of the concrete near the joints.In Technical Specification for Concrete Structures of Tall Building(JGJ 3-2002),a shear wall with concealed column is simply suggested as taking a reinforcing measure,but how to design this kind of joints is not mentioned at all.In the present work,the mechanical characteristics and seismic behavior of the RC non-planar beam-thin wall joints with concealed column have been carried out.The main contents are listed as follows:1.Based on the classical plate theory,the non-planar bending problem of the shear-wall subjected to non-planar bending moment at the joint is studied.The analytical solutions for stresses,internal forces,the rotational stiffness of the joint and strain energy of the wall are obtained.2.Based on equivalent frame model,equivalent bending width is introduced,which can be determined by the use of the equivalent principles for rotational stiffness or for strain energy.A detailed parameter study of the equivalent bending width is carried out to highlight the primary parameters and the impacting characteristic.3.Low reversed cyclic loading tests on four specimens of RC non-planar beam-thin wall with concealed column joints are conducted to investigate failure modes,ductility, hysteretic behavior,energy dissipation capacity and so on.Combing with elasto-plastic finite element analysis,influences of the concealed column breadth on seismic behavior are nailed down.And then the most reasonable concealed column breadth is obtained, which is defined as effective bending width.4.The calculation formulae for the out-of-plane flexural bearing capacity of the shear wall are proposed for two kinds of different failure modes.The results are compared with that from tests.5.The design method of concealed column of non-planar joints is provided. Moreover,methods on constructional and reinforcement details are suggested.更多还原