Study On The Limit Value Of Plan Dimension For Frame-corewall Structures

Reinforced concrete frame– core wall structures is the most widely used form of a structure in the high-rise building, reinforced concrete core wall as a pivotal role that provided the main resistance to lateral force. On the one hand, the core wall with larger lateral stiffness, when the earthquakes and wind loads as the main service load, lateral displacement of the structure can be good control and avoid to be a structural column plastic hinge or a weak layer. On the other hand, particularly in parts of the upper floors, core wall and frame interaction worked, can play a significant role in energy consumption. Although such a structure with multiple advantages, the study of reinforced concrete core wall particularly of the situation is complicated by the failure mechanism, component strength, stiffness and ductility of the match, seismic performance, and other aspects of the study is far from being thorough. China's current "Technical specification for concrete structures of tall building" JGJ3-2002 (here in after referred to as "Technical specification for tall building"), for different types of structure applicable provisions of the greatest height, the width-depth ratio and a series of requirements, because of historical reasons for some of these provision is based on the experience of the development. The "Technical specification for tall building " 9.2.1 provides that: " core wall should not be less than the width of the structure height degree of 1 / 12." The distinction based on the intensity of the seismic, "Technical specification for tall building " of this general approach is clearly not distinguish too rough. Therefore, this paper based on differences in the intensity of the seismic, models with different width-depth ratio elastic and dynamic response of nonlinear analysis, and finally given the recommended value.In the context of the above analysis, the main researches work finished in this thesis is as followings:①With the changes in intensity Region 6 to 8, in strict accordance with current code 19 Models be designed. Based on theoretical of elastic analysis, the deformation and inner force of numbers of models analyses conducted with the software of ETABS. According to study of the paper, the response state of the component of structures to be analysis and intensity of different aspect ratio values of different width-depth ratio in-depth analysis.②Some of acceleration-histories(5+1,4+1) at rare but probable major earthquakes level were imposed separately to the several structures and the nonlinear dynamic response analyses conducted. Besides, parts of the state of deformation, the inner force composition, plastic deformation and energy consumption were identified. At the same time, according to the above conclusions on the structure of demand for the evaluation of ductility, and were given recommendations of value based on elasticity analysis.From the evaluations of discussions of the results presented in this paper, the main specific conclusions are given below:①Through the different model analysis showed that low-intensity zones (6 degrees) wind load greater than the level of earthquake, and it to be the major role in control. In Intensity Region 7, wind load level equal to earthquake. The earthquake level of 8 degrees increase to several times than 6 degrees, the level of response to the earthquake caused substantial wind load beyond, and to be a major role.②In Intensity Region 6, the examples keep elastic under earthquake, only some components of concrete element cracking in tension, and reinforcement elements not yield. Above phenomenon reflects the two main issues: on the one hand that the level of Intensity Region 6 of earthquakes is small, even in the rare case of earthquake standards is not sufficient to make the frame to hinge; On the other hand, indicate that the frame-core wall structure Greater rigidity, despite the reduced size of core-wall remained a better lateral rigidity. At the same time, in Intensity Region 6 and various examples in the rare event of earthquakes under the standard level of response to basically the same, because the structure did not enter the yield showed no significant difference.④Based on the multi-input nonlinear dynamic analysis of results showed that the core-wall size of the commitment to reduce, then the deformation, inner forces take on by frame have increased, the coupling beam deformation slowed. From the distribution of the hinge, borne by the overall frame of deformation increased, there were somewhat different in the distribution of plastic hinge on the wall with some other study. Plastic deformation of the frame are concentrated in the beam end, and the development of plastic are not deep in demand around 1.2, while the frame has a good ductility and the ability of energy reserves, according to the paper, this study guide frame to produce plastic deformation, both followed the Code frame as a second line of defense measures, and to some extent released the burden of shear walls, take full advantage of the two parts of the structure and ensure that the overall performance⑤Based on elastic and dynamic response of nonlinear analysis, based on a comprehensive study of deformation, distribution of inner forces , the element plastic deformation, and other indicators of the development characteristics of the situation. From the results of the study, the typical model of this kind of frame-core wall that could use the value of width-depth ratio in this paper. At the same time, if the actual project structure with additional strengthening, this value can be further relaxed.