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1.
一类多层偏心结构的地震反应研究 总被引：6，自引：0，他引：6
本文用空间的两向抗侧力体系振动模型对五层结构分别分析了首层偏心,中间层偏心,顶层偏心和均匀偏心等不同偏心情况下的弹性地震反应规律,研究了静力偏心距,结构的基本平动周期,平扭频率比,非激励方向的平动频率等对结构的名义基底剪力和偏心层构件的最大剪力系数的影响。 相似文献
2.
多层钢结构基础隔震性能研究 总被引：1，自引：0，他引：1
本文用算例按基底剪力法,振型反应谱法和时程分析法分析了多层基础隔震钢结构和多层钢筋混凝土结构及其对应的非隔震结构的地震力和层间剪力。 相似文献
3.
为研究核心筒抗震性能水准及其指标限值,完成了3个核心筒拟静力试验,记录了损伤过程及对应的层间位移角。在现有核心筒研究成果及国内外规范的基础上,将核心筒的抗震性能水准划分为4个等级,并给出了相应的宏观描述。通过总结相关试验研究结果,发现《建筑抗震设计规范》(GB50011-2010)对层间位移角限制过于严格,考虑到结构带裂缝工作,层间位移角限制过严会增加建筑成本,并导致结构自重增加而不利于抗震,故建议适当放宽核心筒的层间位移角限值,分别给出框架-核心筒及筒中筒结构最大层间位移角建议值。 相似文献
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Cyclic testing has been carried out on two 1/4 scale of (G+2) soft storey RC frame building models to evaluate the nonlinear performance under cyclic loading. The first model has been designed only for gravity loading and the second model has been designed for gravity and earthquake loading. The different pushover parameters of the frames such as load-deformation curve, displacement and storey drift profile and the failure pattern have been evaluated. These parameters are used for up-gradation and comparison of the nonlinear analytical modeling of the soft storey RC frame building. The nonlinear analytical models have been updated at three stages i.e. linear range, nonlinear range and finally at failure stage. The % of error between the experimental and analytical results for different pushover parameters has also been evaluated. 相似文献
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In this paper, torsional response of nonductile structures with soft‐first‐storey subjected to bidirectional ground motions is studied using a simplified two‐storey model with two‐way eccentricities. The stiffness ratio of second storey to first storey is varied to create different levels of soft‐first‐storey effect, while the stiffness eccentricity is varied to create torsional effects. Different overstrength ratios are used in the simplified models to study the response of structure with different structural capacity. Hysteretic model with strength deterioration and stiffness degradation properties is used to capture the deterioration of element stiffness and strength. Ductility capacity of 2.0 is used as the models are for nonductile structures. In general, displacement amplification of irregular model with respect to regular model increases as stiffness ratio increases, while no consistent trend of changes in displacement amplification is found with increase in stiffness eccentricity. It is found that the displacement amplification due to only soft‐first‐storey effect can be conservatively taken as 1.5. Coupling of torsional and soft‐first‐storey effects is more significant in affecting the displacement amplification of elements at flexible side. The trend of changes in displacement amplification of elastic system is similar to that of inelastic system. The displacement amplification of elements at the flexible side is larger than that at the stiff side. The elements at the flexible side in the direction of shorter uncoupled lateral period have larger displacement response than those in the orthogonal direction. Ductility demand–capacity curves subsequently constructed can be used to approximately assess the seismic performance of existing structures and as guidelines for designing structures in Singapore to withstand the maximum credible earthquake considering the coupling of torsional and soft‐first‐storey effects. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Ario Ceccotti Carmen Sandhaas Minoru Okabe Motoi Yasumura Chikahiro Minowa Naohito Kawai 《地震工程与结构动力学》2013,42(13):2003-2021
Multi‐storey buildings made of cross‐laminated timber panels (X‐lam) are becoming a stronger and economically valid alternative in Europe compared with traditional masonry or concrete buildings. During the design process of these multi‐storey buildings, also their earthquake behaviour has to be addressed, especially in seismic‐prone areas such as Italy. However, limited knowledge on the seismic performance is available for this innovative massive timber product. On the basis of extensive testing series comprising monotonic and reversed cyclic tests on X‐lam panels, a pseudodynamic test on a one‐storey X‐lam specimen and 1D shaking table tests on a full‐scale three‐storey specimen, a full‐scale seven‐storey building was designed according to the European seismic standard Eurocode 8 and subjected to earthquake loading on a 3D shaking table. The building was designed with a preliminary action reduction factor of three that had been derived from the experimental results on the three‐storey building. The outcomes of this comprehensive research project called ‘SOFIE – Sistema Costruttivo Fiemme’ proved the suitability of multi‐storey X‐lam structures for earthquake‐prone regions. The buildings demonstrated self‐centring capabilities and high stiffness combined with sufficient ductility to avoid brittle failures. The tests provided useful information for the seismic design with force‐based methods as defined in Eurocode 8, that is, a preliminary experimentally based action reduction factor of three was confirmed. Valid, ductile joint assemblies were developed, and their importance for the energy dissipation in buildings with rigid X‐lam panels became evident. The seven‐storey building showed relatively high accelerations in the upper storeys, which could lead to secondary damage and which have to be addressed in future research. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
8.
混凝土小砌块约束砌体结构,由于加入芯柱、构造柱、圈梁,使结构整体性提高,因此具有较好的抗震性能和发展前景。通过整理94个混凝土小砌块约束砌体墙片试验数据,考虑权重,统计了混凝土小砌块约束砌体墙片延性系数,给出了延性系数与高度、延性系数比与高宽的关系,同时给出了层间开裂位移角、层间极限位移角公式,以及接近倒塌时混凝土小砌块约束砌体结构层间位移的计算公式,并与一个八层混凝土小砌块约束砌体结构的动力时程分析结果进行了对比,结果显示,最大误差在顶层,为17.7%,因此,所提层间位移计算公式是可以满足工程精度需要的,为混凝土小砌块约束砌体结构基于性态的抗震分析提供参考。 相似文献
9.
一种直接基于位移的结构抗震设计方法 总被引：1，自引：1，他引：0
利用我国现行抗震规范,直接根据结构的底层层间目标位移反向求取结构的底层层间屈服剪力;给出了该屈服剪力与结构基底剪力之比的数学表达式,初步分析了影响该比值的主要因素及其影响规律。在此基础上,提出了一种新的直接基于位移的结构抗震设计方法。最后,通过算例分析初步考察了该方法的可行性。 相似文献
10.
A new simplified model for analysis and design of multistorey buildings is developed. The model is based on a single super-element per building storey capable of representing the elastic and inelastic properties of the storey. This is done by matching the stiffness matrices and ultimate yield surface of the storey with that of the element; this surface relates storey shear and storey torque. For practical convenience, these surfaces are parametrized in terms of seven important physical parameters controlling the seismic response of asymmetric structures. Several numerical studies showed that the accuracy of the super-element model is satisfactory for most design purposes; the errors in peak responses are expected to be less than 20 per cent for most practical structures. Among the important advantages of this simplified model is that the time required in formulating, analysing and interpreting the structural model and its response is at least an order of magnitude smaller than for any conventional 3-D inelastic model. This enables the engineer to try different structural configurations and, thus, produce designs that have the desired seismic behaviour and are cost-effective. Furthermore, it has been shown through a multistorey building example that the super-element model is a powerful tool for conceptual design of a building. In spite of its simplicity, the model uses an accurate representation of the storey-shear and torque surfaces, which enables it to capture the fundamental features controlling the inelastic behaviour of the building. 相似文献
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《地震工程与结构动力学》2018,47(4):1014-1031
This paper investigates the seismic response of multi‐storey cross‐laminated timber (CLT) buildings and its relationship with salient ground‐motion and building characteristics. Attention is given to the effects of earthquake frequency content on the inelastic deformation demands of platform CLT walled structures. The response of a set of 60 CLT buildings of varying number of storeys and panel fragmentation levels representative of a wide range of structural configurations subjected to 1656 real earthquake records is examined. It is shown that, besides salient structural parameters like panel aspect ratio, design behaviour factor, and density of joints, the frequency content of the earthquake action as characterized by its mean period has a paramount importance on the level of nonlinear deformations attained by CLT structures. Moreover, the evolution of drifts as a function of building to ground‐motion periods ratio is different for low‐ and high‐rise buildings. Accordingly, nonlinear regression models are developed for estimating the global and interstorey drifts demands on multi‐storey CLT buildings. Finally, the significance of the results is highlighted with reference to European seismic design procedures and recent assessment proposals. 相似文献
12.
A new method of stiffness‐damping simultaneous identification of building structures is proposed using limited earthquake records. It is shown that when horizontal accelerations are recorded at the floors just above and below a specific storey in a shear building model, the storey stiffness and the damping ratio can be identified uniquely. The viscous damping coefficient and the linear hysteretic damping ratio can also be identified simultaneously in a numerical model structure. The accuracy of the present identification method is investigated through the actual limited earthquake records in a base‐isolated building. It is further shown that an advanced identification technique for mechanical properties of a Maxwell‐type model can be developed by combining the present method with a perturbation technique. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
13.
The response of autoclaved aerated concrete confined masonry buildings to seismic ground motion has been studied. Three 1:4 scale models of residential buildings with the same distribution of walls in plan but different types of floors and number of stories have been tested on a uni-directional shaking table. Lightweight prefabricated slabs have been installed in the case of the three-storey model M1, whereas reinforced concrete slabs have been constructed in the case of three-storey model M2 and four-storey model M3. Model M1 was subjected to seismic excitation along the axis of symmetry, whereas models M2 and M3 were tested orthogonal to it. Typical storey mechanism, characterised by diagonal shear failure mode of walls in the ground floor in the direction of excitation has been observed in all cases. Taking into consideration the observed behaviour, a numerical model with concentrated masses and storey hysteretic rules has been used to simulate the observed behaviour. Storey resistance curves calculated by a push-over method and hysteretic rules, which take into account damage and energy based stiffness degradation hysteretic rules, have been used to model the non-linear behaviour of the structure. Good agreement between the experimentally observed and calculated non-linear behaviour has been obtained. 相似文献
14.
P.S. Skjærbæk B. Ta?kin P.H. Kirkegaard S.R.K. Nielsen 《Soil Dynamics and Earthquake Engineering》1997,16(6):373-384
A 2-bay, 6-storey model test reinforced concrete frame (scale l:5) subjected to sequential earthquakes of increasing magnitude is considered in this paper. The frame was designed with a weak storey, in which the columns are weakened by using thinner and weaker reinforcement bars. The aim of the work is to study the global response to a damaging strong motion earthquake event of such buildings. Special emphasis is put on examining to what extent damage in the weak storey can be identified from global response measurements during an earthquake where the structure survives, and what level of excitation is necessary in order to identify the weak storey. Furthermore, emphasis is put on examining how and where damage develops in the structure and especially how the weak storey accumulates damage. Besides the damage in each storey the structure is identified by a static load at the top storey while measuring the horizontal displacement of the stories and also visual inspection is performed. From the investigations it is found that the reason for failure in the weak storey is that the absolute value of the stiffness deteriorates to a critical value where large plastic deformations occur and the storey is not capable of transferring the shear forces from the storeys above so failure is unavoidable. 相似文献
15.
Determination of column size for displacement‐based design of reinforced concrete frame buildings 
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下载免费PDF全文 This article reports a method to determine the storey‐wise column size for displacement‐based design of reinforced concrete frame buildings with a wide range of storey drift and building plan. The method uses a computer program based algorithm. The basic relation used in the algorithm is formulated by considering the various possible deformation components involved in the overall frame deformation. As a necessity to represent the deformation component due to plastic rotation of beam members, a relation between the beam plastic rotation and the target‐drift is adopted. To control the dynamic amplification of interstorey drift, a target‐drift dependant design‐drift reduction factor is used. The dynamic amplification of column moment is accounted with the help of an approximate conversion of fundamental period of the building from the effective period of the equivalent SDOF system. To avoid the formation of plastic hinge in column members, a design‐drift dependant column–beam moment capacity ratio is used. The method successfully determines the storey‐wise column size for buildings of four plans of different varieties, heights up to 12 storeys and target‐drift up to 3%. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
16.
《地震工程与工程振动(英文版)》2016,(2)
Open Ground Storey(OGS) framed buildings where the ground storey is kept open without infill walls, mainly to facilitate parking, is increasing commonly in urban areas. However, vulnerability of this type of buildings has been exposed in past earthquakes. OGS buildings are conventionally designed by a bare frame analysis that ignores the stiffness of the infill walls present in the upper storeys, but doing so underestimates the inter-storey drift(ISD) and thereby the force demand in the ground storey columns. Therefore, a multiplication factor(MF) is introduced in various international codes to estimate the design forces(bending moments and shear forces) in the ground storey columns. This study focuses on the seismic performance of typical OGS buildings designed by means of MFs. The probabilistic seismic demand models, fragility curves, reliability and cost indices for various frame models including bare frames and fully infilled frames are developed. It is found that the MF scheme suggested by the Israel code is better than other international codes in terms of reliability and cost. 相似文献
17.
This paper examines the distribution of seismic drift demands in multi-storey steel moment frames designed to the provisions of Eurocode 8, with due account of the frequency content of ground motion. After providing an overview of current design rules, selected results from a detailed parametric investigation into inelastic drift demands are presented and discussed. The study includes extensive incremental dynamic analyses covering a wide range of structural characteristics and a large suite of ground motion records. The mean period is adopted in this work as a measure of the frequency content of ground motion. Prediction models for maximum global and inter-storey drift demands are presented and shown to be primarily affected by the fundamental-to-mean period ratio and the behaviour factor. Particular attention is given in this paper to the influence of the relative storey stiffness ratio on the distribution of drift demands over the height of the structure. In order to achieve a comparatively uniform drift distribution, a target relative storey stiffness ratio, incorporating the structural and ground motion characteristics, is proposed for design purposes. Finally, the implications of the findings on typical design procedures are highlighted, and possible improvements in codified guidance are discussed. 相似文献
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The dynamic, bi-linear response behaviour of a series of eight storey shear buildings subjected to simulated earthquake excitation is studied. The specific objective of the investigation is to determine under what conditions a yielding first storey can adequately protect the upper storeys from significant yielding. Two classes of buildings are considered: stiff (0.5 sec period) and flexible (2.0 sec period), and the basic parameters considered in the yielding first storey are the yield force level and the bi-linear stiffness. The results demonstrate that a very low yield force level and an essentially perfectly plastic yielding mechanism are required in the first storey to provide effective protection to the superstructure. Moreover, the required displacement capacity of such an effective first storey mechanism is found to be very large. 相似文献
20.
Zoran T. Rakicevic Aleksandra Bogdanovic Dimitar Jurukovski Peter Nawrotzki 《Bulletin of Earthquake Engineering》2012,10(3):1049-1073
A shaking table testing of a 16.6 t five storey steel frame structure with and tuned mass damper (TMD) named as Tuned Mass Control System (TMCS) installed at the top has been carried out in the Dynamic Testing Laboratory at the Institute of Earthquake Engineering and Engineering Seismology (IZIIS) in Skopje, Republic of Macedonia. For estimation of the effectiveness of Tuned Mass Control System (TMCS) large number of shaking table experiments have been performed. Simulating different earthquake time histories on the model structure with and without TMCS it has been demonstrated that this system is capable to reduce the responses in order from 10% to more than 50% depending on the frequency content of the seismic input and the corresponding sensitivity of the structure. Given a high quality analytical model of a structure and a dynamic absorber, a series of variant analyses have been performed within the study to investigate the effect of the individual parameters and evaluate the efficiency of the dynamic absorber. The analyses have been performed to define the effect of the location of the absorber, also, upon the dynamic behaviour of the structure in the case the absorber is installed at the different level (storey) of the structure. Comparative analysis of the structure with TMCS having optimally tuned its mechanical properties versus structure that has TMCS having the same mechanical properties as tested specimen showed that the TMCS additionally improves the structural behaviour, depending on frequency content of earthquake excitation. 相似文献