| Coupling beams are important elements in coupled walls. They are ligaments for passing force between single shear walls, and their linear stiffness is one of the key factors of affecting lateral stiffness of coupled walls and the internal forces in coupled walls , furthermore they are the first position for earthquake energy dissipation in seismic coupled walls. On the one hand, coupling beams with small aspect ratio are sometimes used due to architectural requirement; on the other hand, because shear walls in frame-shear walls and frame-tube structures bear most horizontal forces, coupling beams with small aspect ratio need be chosen to guarantee lateral stiffness required. However, for small span-to-depth ratio coupling beams are counter flexural deep beams restrained at their two ends and points of contraflexure at the center of the span, the rules of their carrying forces and deformation are not like common deep beams. If these kinds of coupling beams in seismic coupled walls are designed with seismic design methods of the normal frame beams, test investigation shows that they can't avoid to occur shear failure very early, so that their ductility demand can't be satisfied to the structure. So far domestic and foreign researches have not yet found out an effective reinforcement arrangement scheme for convenient construction and guaranteeing the occurrence of shear failure after coupling beams attaining displacement ductility required. Seismic design method of coupling beams with small aspect ratio was one of important problems catching notice at the newly revising structure design codes just completed, and it was discussed seriously at the harmonizing meeting of China Code for Seismic Design of Structures, China Code for Design of Concrete Structure and The Code for Design of Reinforced Concrete High-rise Structure. However, because of the insufficiency of experimental research, unanimous opinions were not obtained. At this background, though coupling beams with the small ratio of the span to depth have no sufficient test results, in order to satisfy the needs of engineering design, The Code for Design of Reinforced Concrete High-rise Structure (JGJ3-2002 ) still adopt the design method of decreasing the maximum shear force and increasing the quantity of stirrups. But in China Code for Design of Concrete Structures (GB 50010-2002) the content of seismic design methods for these kinds of coupling beams continue to be blank.Aiming at this important problem to be urgently settled in engineering design, the research group in which the author of this thesis is have carried out a series of testinvestigations on coupling beams with small aspect ratio. Firstly, the Master Zhang Binbin's tests further verified that the design methods brought forward by The Code for Design of Reinforced Concrete High-rise Structure (JGJ3-2002) can not satisfy basic seismic requirement. At the same time, our research group find that some acceptable improved reinforcement arrangement scheme in domestic and foreign researches can not attain satisfying ductility performance.At the basis of the summary of reinforcement arrangement scheme already put forward, our research group brings forward a reinforcement arrangement scheme having good applicability in engineering, namely the reinforcement arrangement scheme of adding the diagonal bars and rhombic inclined bars on the basis of traditional reinforcement. The long period cyclic tests of four specimens near to sufficient dimension made by the Master Cao Yunfeng prove that the reinforcement arrangement scheme can obtain favorable displacement ductility and plastic energy dissipation capacity for the coupling beams with the small aspect ratio of 1.0.To go deep into the research further, this thesis concentrates on the two aspects following:(1)The author of this thesis carries out the long period cyclic test of five specimens near to sufficient dimension to further verify: 1) the probability that the upper limit of shear-resistant ability increases to Vu = 0.2fcbh0 or higher;...
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