bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental study of seismic response of buildings with supplemental fluid dampers
Authors: Constantinou M. C. , Symans M. D. 
Published: April 2007

AbstractThis paper presents the results of an experimental study of the seismic response of buildings with supplemental fluid damping devices. These devices operate on the principle of fluid flow through orifices specially shaped so as to produce damping forces proportional to the velocity, i.e. the devices operate as linear viscous dampers. The experimental results demonstrate that the addition of fluid dampers to the tested steel model structure resulted in reductions of interstory drifts, floor accelerations and story shear forces by factors of two to three in comparison with the response of the same structure without the dampers.
Nonlinear static finite element analysis of reinforced masonry walls in tall buildings
Authors: Ewing Robert D. 
Published: April 2007

AbstractA finite element computer program or code, FEM/I, has been developed for the nonlinear, static analysis of reinforced masonry building components subjected to in‐plane loading. The masonry is represented by a material with bimodular orthotropy, and includes tension stiffening, compression softening, and strain softening, as well as a degrading unloading rule. The masonry model incorporates a tension crack orientation adjustment approach, where the orientation of the final cracks can be different from the initial cracks. The model also includes a compressive strength reduction after tensile cracking normal to the principal compressive strains. Additionally, the model includes a compressive strength increase due to lateral compressive confinement. The reinforcement is represented by an orthotropic material with a bilinear stress‐strain relationship and includes unloading. The FEM/I code is operational on IBM compatible personal computers, such as the 286/386/486 systems. This capability makes the developed technology available to a large group of engineers and researchers, since a large main frame computer is not required to operate the program. The computer program is expected to be particularly useful to designers of tall reinforced masonry buildings that contain components with unusual configurations. These components can be analyzed to properly assess their structural performance.
Conditions that give rise to unusually large long period ground motions
Authors: Somerville Paul , Graves Robert 
Published: April 2007

AbstractSeveral ground motion conditions that are of little concern for conventional structures can be quite important for structures having natural periods longer than 1 s. Firstly, a large long‐period pulse of motion, due to the effect of rupture propagation (directivity), is observed in the direction normal to the fault at strong motion stations located close to the fault. The fault‐normal motions are about twice as large as the fault‐parallel motions for periods longer than about 1 s. The importance of this effect, especially in strike‐slip earthquakes, has probably been underestimated in existing ground motion attenuation relations because until very recently most of the near‐fault strong motion data from large earthquakes have come from thrust earthquakes, for which directivity effects are usually less pronounced. Near‐fault recordings of the 1971 San Fernando, 1979 Imperial Valley, 1989 Loma Prieta, and 1992 Landers, California, earthquakes show large directivity effects. We describe the systematic characteristics of the directivity effect derived from empirical analysis of recorded data and from synthetic seismogram modeling of these data. Secondly, the trapping and amplification of long period waves by sedimentary basins can generate amplitudes that are significantly larger than those calculated from simple ID models of site resonance. Using a ID model with a plane wave incident from below, it is not possible to trap energy in the near‐surface sediment layers. However, for 2D and 3D basin models, waves become trapped as they enter the thickening edge of a basin, and partially escape as they reach the thinning edge of the basin. We show evidence from both recorded data and synthetic seismogram modeling of the San Fernando and Loma Prieta earthquakes that the surface waves are confined to the basin and are not recorded at rock sites adjacent to the basin. This implies that the long period ground motion response at sites within these basins is not adequately represented by the conventional approach of vertically propagating an adjacent rock recording through a ID soil column.
On the lateral response of regular highrise frames
Authors: Grigorian Mark 
Published: April 2007

AbstractThis paper introduces a simple approach for the study of the structural phenomena associated with the lateral response of regular highrise frames. The concept is based upon the assumption that the structure is composed of imaginary modules that fit within the actual bays of the framework, and that all imaginary modules deform through similar shapes by formation of points of inflexion at similar locations. The imaginary modules of a story are combined to form an equivalent ‘basic module’ that possesses the same structural characteristics as the corresponding story level subframe. The concept is used to establish an analogy between the lateral response of highrise structures and discretized Timoshenko beam‐columns with similar boundary conditions. The properties of the basic module have been employed in conjunction with the techniques of finite difference calculus to derive the governing equation of motion of a regular discretized Timoshenko beam under uniform compression. The use of the concept is further utilized to obtain a number of closed form formulae for the initial design of multistory structures. These include expressions for the determination of the natural frequencies, theP‐delta effects, as well as the critical buckling loads of regular multistory frames. Numerical examples have been provided to demonstrate the applications and the simplicity of the proposed solutions.
System of programs for analysis of three‐dimensional shear wall structures
Authors: Wdowicki Jacek , Wdowicka Elżbieta 
Published: April 2007

AbstractThe paper presents a system of programs for calculating stresses and displacements in three‐dimensional shear wall structures with uniform properties throughout the height. The analysis is carried out on the basis of the continuous connection method. The system allows for considering lateral and vertical loads, arbitrarily located in the plan and arbitrarily distributed along the height. The system is user‐oriented and inexpensive in operation. Two numerical examples are given in the paper.
Secondary web‐flange interaction in framed‐tube buildings
Authors: Singh Y. , Nagpal A. K. 
Published: April 2007

AbstractIn the conventional plane‐frame model of framed‐tube buildings, only the primary interaction between the web frame and the flange frame is considered, through vertical shear transfer at corner columns. In addition to this, a secondary interaction takes place due to horizontal shear transfer at each floor level, through the floor slab having high in‐plane rigidity. This interaction causes a discrepancy in member forces of a few bottom and top storeys. A simple modification is suggested in the form of an additional cantilever column connected to the conventional plane‐frame model by axial force transfer members at every floor level. The improved model yields member forces in all the storeys that are very close to those obtained using 3D analysis.
Supertall buildings with tuned mass damper
Authors: Youssef Nabih 
Published: April 2007

AbstractThis paper introduces the ‘mega structure’ concept for supertall buildings. This concept incorporates the latest technology for structural energy dissipation and control systems, which are capable of predicting, controlling and modifying building motion/response. The implementation of tuned mass dampers (TMD) on a 150‐story building in Los Angeles is presented. Following a brief introduction to the underlying mathematical theory of TMD, the dynamic response of the building structure is presented demonstrating the effectiveness of TMD in suppressing undesirable building motions. The influence of the TMD configuration on global system efficiency is also investigated via parametric studies.
Structural reliability characterization of precast concrete
Authors: Ekwueme Chukwuma G. , Hart Gary C. 
Published: April 2007

AbstractThe development of structural reliability‐based design criteria requires an uncertainty characterization of structures. This paper proposes a new method of structural reliability characterization for precast concrete frames. Beam—column‐joint subassemblies are designated as the substructures that form the basis of structural reliability characterization as opposed to the use of individual beams and columns.
Optimum structural design based on seismic reliability and response distribution
Authors: Asano Koichiro , Harada Hiroyuki 
Published: April 2007

AbstractAn analytical approach to the optimum structural design parameters is developed on the basis of seismic reliability and inter‐story response distribution. An earthquake‐like stationary random excitation being assumed, probabilistic earthquake response is estimated as the solution of a simple simultaneous algebraic equation. Based on this probabilistic earthquake response, the optimum parameters are determined by selecting seismic structural reliability and an inter‐story response distribution index as objective functions. The validity of this approach is demonstrated by examining the perspective and contour lines of the objective functions regarded as a function of design parameters for elastic structural systems with six degrees of freedom. The possible application of this approach is also presented to the determination of elasto‐plastic structural parameters with bi‐linear hysteretic characteristics. Other aspects of the approach's validity are also examined from the response distribution viewpoint for the elastic structural system with recorded strong earthquake motions. The influence of the higher modal response and the earthquake's predominant angular frequency on the optimum parameters are also discussed.
Two‐stage gravity load analysis of framed‐tube buildings
Authors: Singh Y. , Nagpal A. K. 
Published: April 2007

AbstractA two‐stage solution procedure has been presented for the gravity loading (live load) analysis of framed‐tube buildings. In the first stage, the solution is estimated by solving a simplified model and a number of substructures with much reduced numbers of degrees of freedom. In the second stage, the Gauss‐Seidel iterative procedure is used to obtain the accurate solution. The proposed two‐stage solution procedure requires a CPU time that is only a fraction of that needed in the standard solution procedure. The number of computer storage locations required is also small. Additionally, by using the proposed procedure, framed‐tubed buildings of practically any size can be analysed on microcomputers.
Seismic response of building structures with flexible inelastic diaphragm
Authors: Dolce M. , Lorusso V. D. , Masi A. 
Published: April 2007

AbstractThe inelastic response of one‐storey buildings subjected to lateral loads is analysed, making allowance for the real in‐plane rigidity and strength of the floors. The structural model consists of a floor diaphragm supported by seven vertical resisting elements with degrading stiffness properties. The elastic design analysis is carried out by modelling the floor diaphragm as a rigid or, alternatively, as a flexible beam. The actual nonlinear response of 240 structures is studied via numerical simulations. Different stiffness and strength distributions in the lateral resisting systems and in the diaphragm are considered. The results of the investigation emphasize the need for an adequate design of the floor diaphragm as a structural element. Also, the results show that the deformability of the diaphragms plays an important role only if the lateral‐force resisting system has a markedly non‐uniform stiffness distribution; even in such cases, however, adopting the rigid diaphragm hypothesis leads to a more conservative design.
Symmetry breaking: The effect of randomizing mass and stiffness on building response to winds and earthquakes
Authors: Meecham William C. , Mal Ajit K. 
Published: April 2007

AbstractSymmetry‐breaking can have profound consequences for the response of periodic structures. Examples of such structures include tall buildings and their response to winds and earthquakes; repeated trusses in bridge structures and, similarly, repeated trusses for space vehicles; there are many others. These results are discussed for various dampings, various building heights and various excitations with a view to finding building response. Variation of up to ± 20% in the parameters shows displacements (RMS or maximum) of up to two to three times those for the deterministic structure (no variation in parameters). Buildings of 3 to 50 floors are considered. The greatest effects are seen near lower frequency resonances for all structures. The biggest effects are seen for the tallest structures: in such cases amplification of up to a factor of four occur.
A survey of glazing system behavior in multi‐story buildings during hurricane andrew
Authors: Behr Richard A. , Minor Joseph E. 
Published: April 2007

AbstractA focused survey of glazing system behavior in multi‐story buildings in the direct aftermath of Hurricane Andrew was conducted. Seventeen buildings and four building complexes were examined between 26 August and 30 August, 1992. The buildings surveyed spanned a 32 km (19 mile) distance from Miami on the north to Cutler Ridge on the south. With few exceptions, glazing systems performed poorly and damage to building contents was extensive. The following specific observations were made: (1) impacts from windborne debris were a dominant cause of glass failure; (2) wall system anchorages sometimes failed; (3) prevention of ‘blow‐through’ after internal pressurization significantly mitigated storm damage to building interiors; and (4) outer‐lite‐only failures occurred on some insulating glass units. Results of the survey underscore the vital importance of maintaining the integrity of a building envelope during a severe windstorm. Windborne debris must be considered in the design of architectural glazing systems, as must proper anchorages of glazing systems to building framing members.
A computer‐based design support system for steel frame structures
Authors: Fuyama Hiroyuki , Krawinkler Helmut , Law Kincho H. 
Published: April 2007

AbstractThis paper describes the development and utilization of a computer‐based support system for the conceptual design of moment resisting steel frame structures. This design support system, ‘Building Engineering and Reasoning Tool’ (BERT), incorporates a behavior‐based methodology for designing structural members that satisfy strength and interstory drift requirements due to gravity and lateral (earthquake) loads. Given the loading conditions and building configuration, BERT has the capability of selecting efficient member sizes through reasoning about the behavior of the structure. Different configurations can be evaluated by means of a cost estimating scheme that incorporates steel material, fabrication, and erection costs. This paper focuses on a discussion of the design methodology implemented in BERT. Illustrative examples are presented to demonstrate the range of applications of this design support system.
Rescue mission of Ryounkaku Tower in Great Kanto Earthquake; travelling back in time to 1923 to apply the latest aseismic technologies
Authors: Kobori Takuji , Nakahara Mitsuharu 
Published: April 2007

AbstractIn 1890, a twelve‐story octagonal sight‐seeing tower was constructed as a high rise building in Tokyo Asakusa Park. In 1923, however, the top of the tower from the eighth floor up collapsed due to the Great Kanto Earthquake. In order to raise public interest in disaster prevention, we performed as a virtual experiment a conceptual attempt to save the tower without fundamentally changing its architectural characteristics by applying the most advanced structural control techniques. In the simulation, the top of the tower from the eighth floor experienced, almost exactly as described in historical record, a shear fracture during the initial period of principal shock. The modified Ryounkaku Tower would have ensured a comfortable margin of safety even against earthquakes more severe than the Great Kanto Earthquake in 1923.
Mode coupling in the torsional—flexural buckling of regular multistorey buildings
Authors: Zalka K. A. 
Published: April 2007

AbstractAn analogy is established between the mode coupling of columns under concentrated end forces and those subjected to uniformly distributed axial forces. It is demonstrated that the cubic equation derived for the mode coupling of columns under end forces can be used directly for the more practical case of cantilevers under uniformly distributed axial load. Simple closed‐form formulae and design tables are given for the torsional—flexural buckling of cantilevers. These formulae can be used directly for the spatial stability analysis of core supported regular multistorey buildings. A numerical example is provided to show the step‐by‐step procedure to be followed in practical structural design for stability. The results of a series of tests on small‐scale multistorey building models are presented. The loadbearing system of the models consists of columns, shear walls and support cores. The results indicate that the contribution of the columns to the lateral and warping stiffness of the support system may be of considerable magnitude. The more sensitive the structure is to torsion, the greater the effect of the columns.
Utilization of high‐strength concrete in tall buildings
Authors: Hu Qingchang , Zhu Zingquan 
Published: April 2007

AbstractSince 1988, the utilization of high strength concrete has increased owing to the development of tall buildings in many cities of China. High strength concrete is usually used for columns; the advantages are saving floor area and providing better seismic behavior. Composite columns are also adopted under heavily loaded conditions. In this paper, the design of two representative tall buildings in Beijing are briefly introduced.
Deficiencies of design‐spectrum compatible accelerograms
Authors: Naeim Farzad , Lew Marshall 
Published: April 2007

AbstractFrequency‐domain scaled, design spectrum compatible acceleration time histories (DSCTH) are widely used in the analysis and design of special structures, particularly seismic‐isolated buildings. At the first glance, it seems that DSCTH records furnish earthquake resistant designers with a consistency and compatibility bridge between the two very different worlds of elastic and inelastic response. Closer examination reveals, however, that there are significant potential problems associated with indiscriminate use of DSCTH records in seismic design.
Estimation of wind loads for a super‐tall building (SSH)
Authors: Shimada Kenji , Hibi Kazuki 
Published: April 2007

AbstractA procedure is presented for estimating the wind load acting on the Shimizu Super Highrise, which is based on results obtained from wind tunnel experiments. The force balance test and the two‐degree‐of‐freedom aeroelastic model test were performed. A considerable reduction in the dynamic wind force and moderate variations in the response for various wind directions could be obtained as a result of suppression of vortex shedding attributed to the effect produced by the alternate arrangement of different cross sections along the height of the building.
Estimating seismic drifts of multistory reinforced concrete frames
Authors: Uang Chia‐Ming , Maarouf Ahmed 
Published: April 2007

AbstractIn order to estimate maximum roof and story drifts occurring in major earthquakes, seismic design provisions usually specify a deflection amplification factor (DAF) to amplify elastic design drifts. A comparison of several seismic design provisions indicated that the deflection amplification factor in both the UBC and NEHRP Recommended Provisions, being equal to 3Rw/8 and Cd, respectively, is very low and could lead to unconservative drift estimations. Since a reliable estimate of actual seismic drifts is essential for developing a performance‐based seismic design provision to control both structural and non‐structural damage, an analytical study of the seismic response of three instrumented reinforced concrete building frames located in California was first conducted. In addition to analytical studies, reported test results from shaking table testing of reduced‐scale multistory reinforced concrete frames were used to evaluate the deflection amplification factor. It is confirmed from both the analytical and experimental evidence that drifts developed in major earthquakes are much higher than those predicted by the UBC or NEHRP approach. It is recommended that the deflection amplification factor be increased to at least the seismic force reduction factor (Rw in UBC and R in NEHRP) for estimating maximum drifts.
The use of single diagonal bracing in improvement of the lateral response of tall buildings
Authors: Vafai A. , Estekanchi H. , Mofid M. 
Published: April 2007

AbstractThe improvement of the lateral response of tall buildings is a subject of great concern both in high wind areas and seismic regions. The lateral deflection of a tall building subjected to lateral loads can be decomposed into shear and bending components. Properly oriented single diagonal bracings are introduced in order to bring advantageous interactions between these two modes of deflection resulting in a reduction of the overall lateral deflection of the frame. The deflection of a panel with a single diagonal, when subjected to vertical downward load, has a lateral component caused by the axial force developed in the single brace, which, due to asymmetry, results in the lateral deflection. In order to restrict the panel from lateral deflection a compensating lateral force is required. By locating the single diagonal bracings in an improved manner, the vertical tension and compression on the opposite sides of the frame caused by the bending effect automatically generate the above mentioned lateral compensating force which opposes the inter story drift. A simple truss model is introduced to study the relationship between the vertical loading and the lateral load required to retain the vertical alignment of a panel with a single diagonal. This relation is then studied in detail and the optimal values of the height‐to‐width and brace‐to‐column stiffness ratios, needed to produce the maximum equilibrating lateral force are computed. Further, the single diagonal bracings are applied to typical building frames. Results from elastic analyses are compared with that of the conventional X‐braced frame. Pilot analysis shows a reduction of about 2% in the lateral deflection of a typical 24 story braced frame building with rigid connections and five bays using the proposed bracing scheme.