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The design code for each country is revised and updated based on an expected zone’s seismic intensities,geotechnical site classifications,structural systems,construction materials and methods of construction in order to provide more realistic considerations of seismic demand,seismic response,and seismic capacity.Based on the aforementioned provisions,structures designed according to different seismic codes may yield different performances for the same level of hazard.This study aims to investigate and compare the induced responses related to the earthquake-resistant design of reinforced concrete(RC)buildings according to the Saudi building code(SBC-301),American code(ASCE-7),uniform building code(UBC-97),and European code(EC-8).In order to account for the provision regarding the hazard specification and its effect on the induced seismic responses,four regions in the Kingdom of Saudi Arabia with different seismic levels are selected.The code provisions related to the specification of site classification and its effect on the induced design base shear are investigated as well.Significant differences are observed in the induced responses with the variation in seismic design codes for the considered seismic hazards and site classifications. 相似文献
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Christoph Mahrenholtz Pao‐Chun Lin An‐Chien Wu Keh‐Chyuan Tsai Shyh‐Jiann Hwang Ruei‐Yan Lin Muhammad Y. Bhayusukma 《地震工程与结构动力学》2015,44(1):59-78
Damage to buildings observed in recent earthquakes suggests that many old reinforced concrete structures may be vulnerable to the effects of severe earthquakes. One suitable seismic retrofit solution is the installation of steel braces to increase the strength and ductility of a building. Steel bracings have some compelling advantages such as their comparatively low weight, their suitability for prefabrication, and the possibility of openings for utilities, access, and light. The braces are typically connected to steel frames that are fixed to the concrete structure using post‐installed concrete anchors along the perimeter. However, these framed steel braces are not without some disadvantages such as heavier steel usage and greater difficulties during the installation. Therefore, braces without steel frames appear to be an attractive alternative. In this study, braces were connected to gussets furnished with anchor brackets, which were fixed by means of a few post‐installed concrete anchors. The clear structural system and the increased utilization of the anchors allowed the anchorage to be designed precisely and economically. The use of buckling‐restrained braces (BRBs) provides additional benefits in comparison with conventional braces. BRBs improve the energy dissipation efficiency and allow the limitation of the brace force to be taken up by the highly stressed anchorage. Cyclic loading tests were conducted to investigate the seismic performance of BRBs connected with post‐installed anchors used to retrofit reinforced concrete frames. The tests showed that the proposed design method is feasible and increases strength as well as ductility to an adequate seismic performance level. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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In regions of low to moderate seismicity in North America, reinforced masonry structures are mostly partially grouted. The behavior of such structures under lateral seismic loads is complicated because of the interaction of the grouted and ungrouted masonry. As revealed in past experimental studies, the performance of partially grouted masonry (PGM) walls under in-plane cyclic lateral loading is inferior to that of fully grouted walls. However, the dynamic behavior of a PGM wall system under severe seismic loads is not well understood. In this study, a full-scale, one-story, PGM building designed for a moderate seismic zone according to current code provisions was tested on a shake table. It was shown that the structure was able to develop an adequate base shear capacity and withstand two earthquake motions that had an effective intensity of two times the maximum considered earthquake with only moderate cracking in mortar joints. However, the structure eventually failed in a brittle manner in a subsequent motion that had a slightly lower effective intensity. A detailed finite element model of the test structure has been developed and validated. The model has been used to understand the distribution of the lateral force resistance among the wall components and to evaluate the shear-strength equation given in the design code. The code equation has been found to be adequate for this structure. Furthermore, a parametric study conducted with the finite element model has shown that the introduction of a continuous bond beam right below a window opening is highly beneficial. 相似文献
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Hysteresis steel dampers are widely used in earthquake-resistant structures, where some of them are anisotropic and capable of sustaining earthquake-induced bidirectional deformation. In this paper, a simplified analytical model is proposed for simulating the hysteretic behavior of U-shaped steel dampers with horizontal bidirectional deformation. The proposed model is composed of a series of shear springs with different nonlinear characteristics in a radial configuration, and the Menegotto–Pinto hysteresis model is employed to represent the hysteretic characteristics of the springs. The mechanical and shape-related parameters of the hysteresis model are set according to the multi-directional deformation characteristics of steel dampers. With the aim of validating the effectiveness and applicability of the analytical model, a U-shaped steel damper was used as an example. The pseudo-static hysteretic characteristics of the steel damping element were analyzed and the elasto-plastic seismic response of a curved bridge featuring a steel hysteresis device was investigated. The results showed that the proposed model is sufficiently accurate to simulate the hysteretic behavior of U-shaped steel dampers, and thus provides a practical method to assess U-shaped steel dampers through seismic response analysis. 相似文献
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Nonstructural components(NSCs)are parts,elements,and subsystems that are not part of the primary loadbearing system of building structures but are subject to seismic loading.Damage to NSCs may disrupt the functionality of buildings and result in significant economic losses,injuries,and casualties.In past decades,extensive studies have been conducted on the seismic performance and seismic design methods of NSCs.As the input for the seismic design of NSCs,floor response spectra(FRS)have attracted the attention of researchers worldwide.This paper presents a state-of-the-art review of FRS.Different methods for generating FRS are summarized and compared with those in current seismic design codes.A detailed review of the parameters influencing the FRS is presented.These parameters include the characteristics of ground motion excitation,supporting building and NSCs.The floor acceleration response and the FRS obtained from experimental studies and field observations during earthquakes are also discussed.Three RC frames are used in a case study to compare the peak floor acceleration(PFA)and FRS calculated from time history analyses(THA)with that generated using current seismic design codes and different methods in the literature.Major knowledge gaps are identified,including uncertainties associated with developing FRS,FRS generation methods for different types of buildings,the need for comprehensive studies on absolute acceleration,relative velocity,and relative displacement FRS,and the calibration of FRS by field observations during earthquakes. 相似文献
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In recent earthquakes in developing countries, severe damage was observed on reinforced concrete buildings. This study focuses on exterior beam-column joints with substandard beam rebar anchorage and seismic strengthening by installing wing walls. First, a series of experiments was conducted to investigate the seismic behavior of exterior joints with substandard beam rebar anchorage representing typical Bangladeshi buildings. Two 0.7-scaled exterior joint specimens were tested, and these specimens showed beam rebar anchorage failure and/or joint shear failure. Prior to strengthening of the joint, a series of pullout tests was conducted on postinstalled bonded anchors in low-strength concrete for strengthening design. Then, an experiment was performed to apply the strengthening method by wing walls to one of the exterior joint specimens to improve the integrity, and this method was intended to prevent the failure of beam rebar anchorage. The strengthening method is proposed to extend the development length of beam longitudinal bars by considering the embedment length along the wing walls. The test results verified the effectiveness and applicability of the proposed strengthening method to upgrade exterior RC beam-column joints with deficient beam rebar anchorage. 相似文献
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Reinforced concrete (RC) frame structures are one of the mostly common used structural systems, and their seismic performance is largely determined by the performance of columns and beams. This paper describes horizontal cyclic loading tests often column and three beam specimens, some of which were designed according to the current seismic design code and others were designed according to the early non-seismic Chinese design code, aiming at reporting the behavior of the damaged or collapsed RC frame strctures observed during the Wenchuan earthquake. The effects of axial load ratio,shear span ratio, and transverse and longitudinal reinforcement ratio on hysteresis behavior, ductility and damage progress were incorporated in the experimental study. Test results indicate that the non-seismically designed columns show premature shear failure, and yield larger maximum residual crack widths and more concrete spalling than the seismically designed columns. In addition, longitudinal steel reinforcement rebars were severely buckled. The axial load ratio and shear span ratio proved to be the most important factors affecting the ductility, crack opening width and closing ability, while the longitudinal reinforcement ratio had only a minor effect on column ductility, but exhibited more influence on beam ductility. Finally, the transverse reinforcement ratio did not influence the maximum residual crack width and closing ability of the seismically designed columns. 相似文献
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针对钢筋混凝土高层框支剪力墙结构抗震性能差的缺点,提出采用型钢混凝土（SRC）梁柱框支剪力墙,试验结果表明了其良好的抗震性能。提出了框支剪力墙结构地震反应简化分析模型,将结构简化为由墙单元和框支单元组成的弹簧体系,墙单元采用二元件模型。推导了框支单元刚度矩阵,基于理论公式和试验结果给出了框支单元恢复力模型。根据提出的简化模型,编制了结构地震反应时程分析程序。程序计算结果与ETABS分析结果及振动台试验结果吻合较好,为进一步对SRC框支剪力墙结构进行地震反应分析提供了理论基础。 相似文献
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The paper focuses on the seismic response of walls in dual (frame + wall) structures, with particular emphasis on shear behaviour.
Although dual structures are widely used in earthquake-resistant medium-rise and high-rise buildings, the provisions of modern
seismic codes regarding design of walls for shear are not fully satisfactory, particularly in the (common) case that walls
of substantially different length form part of the same structure. Relevant provisions of the leading seismic codes are first
summarised and their limitations discussed. Then an extensive parametric study is presented, involving two multistorey dual
systems, one with identical walls, and one with walls with unequal length, designed to the provisions of Eurocode 8 for two
different ductility classes (H and M). The walls of the same structures are also designed to other methods such as those used
in New Zealand and Greece. The resulting different designs are then assessed by subjecting the structures to a suite of strong
ground motions, carrying out inelastic time history analysis, and comparing the results against design action effects. It
is found that although modern code procedures generally lead to satisfactory performance (differences among them do exist),
the design of walls seems to be less appropriate in the case of unequal length walls. For this case a modified procedure is
proposed, consisting of an additional factor to account for the relative contribution of walls of the same length to the total
base and an improved envelope of wall shears along the height; this improved method seems to work better than the other procedures
evaluated herein, but further calibration is clearly required. 相似文献
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Hybrid experimental performance of a full‐scale two‐story buckling‐restrained braced RC frame 
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下载免费PDF全文 An‐Chien Wu Keh‐Chyuan Tsai Hsun‐Horng Yang Jie‐Luen Huang Chao‐Hsien Li Kung‐Juin Wang Hsen‐Han Khoo 《地震工程与结构动力学》2017,46(8):1223-1244
This paper proposes a novel implementation of buckling‐restrained braces (BRB) in new reinforced concrete (RC) frame construction. Seismic design and analysis methods for using a proposed steel cast‐in anchor bracket (CAB) to transfer normal and shear forces between the BRB and RC members are investigated. A full‐scale two‐story RC frame with BRBs (BRB‐RCF) is tested using hybrid and cyclic loading test procedures. The BRBs were arranged in a zigzag configuration and designed to resist 70% of the story shear. The gusset design incorporates the BRB axial and RCF actions, while the beam and column members comply with ACI 318‐14 seismic design provisions. Test results confirm that the BRBs enhanced the RCF stiffness, strength, and ductility. The hysteresis energy dissipation ratios in the four hybrid tests range from 60% to 94% in the two stories, indicating that BRBs can effectively dissipate seismic input energy. When the inter‐story drift ratio for both stories reached 3.5% in the cyclic loading test, the overall lateral force versus deformation response was still very stable. No failure of the proposed steel CABs and RC discontinuity regions was observed. This study demonstrates that the proposed design and construction methods for the CABs are effective and practical for real applications. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Deterministic and probabilistic floor response spectra 总被引：1，自引：0，他引：1
The paper presents a comparative study for computing floor response spectra (FRS) for complex structures. For the purpose of validation and evaluation of the methods for practical application, a systematic comparison of two concepts, classical deterministic and probabilistic, was carried out as an example of a nuclear power plants structure. The deterministic method utilizes time history analyses compatible with the prescribed design response spectrum. The probabilistic method uses an analysis of random vibrations for defining the probabilistic FRS influenced by random seismic soil movement. The seismic input is a power spectral density function (PSDF) compatible with the design response spectrum. The probabilistic approach based on PSDF provides satisfying FRS with far less effort and time consumption needed for calculation. 相似文献
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The aim of the present paper is to present a rational procedure for the appropriate selection of the sectional forces needed for the calculation of the longitudinal reinforcement to R/C elements within the context of linear time history analysis. The proposed procedure is based on the maximum normal stresses, which occurs in each relevant cross section, and takes into consideration the critical angle of the seismic excitation, i.e., the angle that yields the maximum value of each response quantity of interest. Moreover, in an attempt to realistically interpret pertinent code provisions, three other code compatible methods of selecting the cross sectional forces are presented and compared to the here proposed method. For this purpose, three single-story buildings subjected to 47 bi-directional strong earthquake ground motions are analyzed. For each ground motion, the longitudinal reinforcement at all critical cross sections is calculated using the above four methods. Furthermore, the necessary reinforcement due to 3 and 7 representative earthquake records, required by the seismic code provisions, is determined. Comparison of results clearly shows that methods compatible with current seismic code provisions can significantly underestimate the necessary reinforcement with regards to the proposed method. 相似文献
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Christopher Trautner Tara Hutchinson Philipp Grosser Roberto Piccinin John Silva 《地震工程与结构动力学》2019,48(2):173-187
Previous research has demonstrated that uplifting-column or rocking building systems may exhibit improved seismic performance, including reductions in total base shear and decreased residual drift, when compared with systems rigidly connected to the foundation. These beneficial effects may be due to lengthened periods, activation of rocking modes, and energy dissipation of base fuse elements. In the current work, several configurations of a miniature steel building with different combinations of base connection and traditional superstructure fuse strength and stiffness were subjected to identical earthquake motions to evaluate differences in demands and performance. The uplifting base connections incorporate highly ductile concrete anchors with long stretch lengths, allowing robust connection performance and easy replacement of damaged connection elements following the seismic event, an advantage over previously tested systems. Testing and dynamic numerical analysis indicates that ductile anchor uplifting systems may reduce total base shear by over 20%, as well as reducing residual structural drift by more than 80%. 相似文献
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This paper presents an experimental investigation on the seismic behavior of H‐beam to circular tubular column connections stiffened by an outer ring diaphragm. An innovative three‐dimensional (3D) connection subassembly testing system was first described. Specimens representative of two‐dimensional (2D) interior columns, 3D interior and exterior columns in a steel building frame were then tested to failure under unidirectional or bidirectional cyclic loads. Various specimen parameters are used to evaluate their effects on connection behavior. Test results indicate significantly different failure modes for 2D and 3D weak panel connections, with panel shear buckling and local distortion of outer diaphragm occurring only for 3D connections. The weak beam connections unexceptionally exhibited final fracture at the junction between diaphragm and beam flange. In contrast with weak beam connections, weak panel connections demonstrated better seismic performance and ductility. As a result, a seismic design philosophy considering panel zone yielding before beam flexural yielding is proposed. Based on experiment observations, small diaphragm width and simplified fillet welding are found to be feasible especially for weak beam connections, improving architectural appearance and facilitating construction. Strength evaluations also suggest that current AIJ design provisions may be appropriate when applied to panel zones in 3D connections. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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The current Indian Standard (IS) code for seismic design of structures (IS 1893:2002) specifies the use of time history analysis
for structures with height greater than 40m. However, for structures less than 40m it recommends the concept of equivalent
static analysis. This study attempts to investigate the adequacy of the current design code when it comes to the actual evaluation
of structures shorter than 40 m subjected to seismic loading using dynamic analysis as opposed to the code specified static
analysis. Incremental dynamic analysis, which subjects a structure to a progressively increasing series of intensity measures,
has been adopted here for the purpose. Three 2D moment resisting steel structures under the 1991 Uttarkashi and the 2001 Bhuj
earthquakes (both of which predate the current IS1893) have been studied—a single storeyed portal frame, a 2 storey 3 bay
frame and a 3 storey 2 bay frame. While it can be argued that two records are never enough for any generalization, and that
only a full probabilistic analysis can determine if the limiting collapse prevention probability has been exceeded for these
structures, the IS code in both cases does significantly under predict the seismic demands on the structures. At the same
time, and perhaps why the codal provisions usually work, the structural capacities are in most cases underestimated as well.
These suggest that a thorough study is in order and that there is scope for rationalization in the IS codal provisions. 相似文献
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Nonlinear dynamic response of r.c. framed structures subjected to near-fault ground motions 总被引：2，自引：1，他引：1
The nonlinear dynamic response of reinforced concrete (r.c.) framed buildings subjected to near-fault ground motions is studied
to check the effectiveness of current code provisions with reference to study cases. Three-, six- and twelve-storey r.c. plane
frames, representative of symmetric framed buildings, are designed according to the European seismic code (EC8), assuming
medium and high ductility classes and stratigraphic profiles A (rock) and D (soft soil) in a high-risk seismic region. The
nonlinear seismic analysis is performed using a step-by-step procedure; a bilinear model idealizes the behaviour of the r.c.
frame members. Artificially generated motions (matching EC8 response spectra for subsoil classes A and D) and horizontal motions
(recorded on rock- and soft soil-site at near-fault areas) are considered. The results indicate that near-fault ground motions
may require a special consideration in the code, in particular when designing r.c. framed structures placed on a soft soil-site;
particular attention should be paid to the design of the frame members of the lower storeys. 相似文献
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国家体育场柱脚锚固性能试验研究 总被引：2，自引：0，他引：2
大跨结构柱脚锚固性能是抗震设计的关键之一。国家体育场柱脚为钢柱脚,该钢柱脚锚固于钢筋混凝土承台中,其受力复杂,以往国内外类似的试验很少。笔者共进行了4个钢筋混凝土承台-钢柱脚试件锚固性能的试验研究,本文介绍其中2个几何尺寸较大的钢筋混凝土承台-钢柱脚试件锚固性能的试验研究概况,1个试件为混凝土承台中配置抗拔钢筋的试件,1个为混凝土承台中未配置抗拔钢筋的试件。通过单向重复加载下的钢柱脚锚固性能试验,对试件的锚固承载力、延性、合理配筋型式等进行了研究。试验结果表明,混凝土承台中配置抗拔钢筋的试件与未配置抗拔钢筋的试件相比其锚固承载力和延性显著提高。在试验基础上,建立了柱脚锚固承载力计算的桁架模型,计算结果与实测结果符合较好。 相似文献
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Empirical‐based out‐of‐plane URM infill wall model accounting for the interaction with in‐plane demand 下载免费PDF全文
下载免费PDF全文 《地震工程与结构动力学》2018,47(3):802-827
The role of masonry infills in the seismic behavior of reinforced concrete buildings has been widely studied in terms of their strength and stiffness contribution in the in‐plane (IP) direction, while fewer studies have been carried out on their response and modeling in the out‐of‐plane (OOP) direction. In this paper, the state of the art in code and literature provisions regarding infills' OOP capacity and seismic demand is presented, together with a review of the experimental tests that have been carried out to investigate infills' OOP behavior and the effects of IP‐OOP interaction. This review aims to collect an experimental database that is used to evaluate the effectiveness of literature and code provisions and to propose a semiempirical approach both for predicting infills' OOP strength, stiffness, and displacement capacity and for modeling the effects of IP displacement demand on OOP behavior and vice versa. Then, the state of the art on modeling of infills' OOP behavior and IP‐OOP interaction is presented together with a new macro model based on the proposed formulations and conceived to represent the IP and OOP behavior by taking into account the mutual interaction effects. Finally, the proposed model is used for an example application on two case‐study buildings, showing the effects of taking into account or neglecting the IP‐OOP interaction phenomena. 相似文献
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进行了3个1/3缩尺的中高剪力墙的抗震性能试验研究,包括1个混凝土中高剪力墙、1个内藏钢框架组合中高剪力墙和1个内藏钢桁架组合中高剪力墙。在试验研究基础上,对比分析了各剪力墙的刚度及其衰减过程、承载力、延性、滞回特性及破坏特征。试验表明:内藏钢框架混凝土组合中高剪力墙的抗震性能比普通混凝土中高剪力墙明显提高;内藏钢桁架混凝土组合中高剪力墙的抗震性能比普通混凝土中高剪力墙显著提高。 相似文献