Prediction of fundamental period of regular frame buildings

2016 ◽  
Vol 49 (2) ◽  
pp. 175-189 ◽  
Author(s):  
Pavan K. Aninthaneni ◽  
Rajesh P. Dhakal
Keyword(s):  
Analytical Methods ◽  
Building Design ◽  
Building Codes ◽  
Eigenvalue Analysis ◽  
Fundamental Period ◽  
Structural Parameter ◽  
Empirical Equations ◽  
Regular Frame ◽  
Frame Buildings ◽  
Rayleigh Method

The most important structural parameter in the estimation of the seismic demand on a building is the natural period of the building’s fundamental/first mode of vibration. There are several existing empirical, analytical, and experimental methods which can be used to estimate the fundamental period of a building. The empirical equations prescribed in the building codes are simple, but they do not consider actual building properties, and are very approximate. On the other hand, analytical methods like Eigenvalue analysis and Rayleigh method are able to consider most of the structural parameters that are known to affect the period of a building. Nevertheless, the analytical methods require considerable effort and expertise; often requiring structural analysis software’s to estimate the fundamental period of a building. In this paper, a generic method is developed to estimate the fundamental period of regular frame buildings and a simple yet reliable equation is proposed. The equation is derived using the basic concept of MacLeod’s method for estimation of roof/top deflection of a frame building, which is modified to more accurately predict the lateral stiffness of moment resisting frames under triangular lateral force distribution typically used in seismic design and analysis of frame buildings. To verify the reliability and versatility of the developed equation, the fundamental periods predicted are compared with the periods obtained from Eigenvalue analysis for a large number of low to medium rise RC frame buildings. The fundamental period predicted using the proposed equation is also verified using the period obtained using the Rayleigh method and measured in experimental tests. Since the proposed equation was found to closely predict the fundamental period, the results are used to study the limitations of the empirical equations prescribed in building codes. The applicability of the proposed equation to predict the fundamental period of low to medium rise frame buildings with minor irregularity is also investigated, and it was found that the proposed equation can be used for slightly irregular frame buildings without inducing any additional error. The proposed equation is simple enough to be implemented into building design codes and can be readily used by practicing engineers in design of new buildings as well as assessment of existing buildings.

EVALUATION OF THE DYNAMIC CHARACTERISTICS FOR SEISMIC DESIGN OF MULTI-STORY BUILDINGS

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Aya Aboelhamd ◽  
Aman Mwafy ◽  
Suliman Gargoum
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Building Codes ◽  
Fundamental Period ◽  
Braced Frames ◽  
Data Set ◽  
Structural Dynamic ◽  
Moment Resisting Frames ◽  
Moment Resisting ◽  
Period Data

The fundamental period of vibration is a critical structural dynamic characteristic in seismic design. Several expressions for the calculation of the fundamental period have been recommended by different building codes and previous studies. However, further studies are still needed to evaluate the design expressions used for the calculation of the fundamental periods and assess the need for further refinement. In this study, comprehensive fundamental period data from two sources is collected and compared with different formulas from building codes and previous studies. The first data set is obtained from 147 instrumented buildings with various lateral force resisting systems (LFRSs). The second set of period data are collected from the dynamic response simulations of selected structures. Different LFRSs are considered, including steel moment resisting frames (SMRFs), reinforced concrete moment resisting frames (RCMRFs), reinforced concrete shear walls (RCSWs), concentrically braced frames (CBFs), eccentrically braced frames (EBFs), masonry structures and pre-cast structures. The correlations between the derived period expressions with those recommended by the design provisions show that the code approach is conservative enough for SMRFs, CBFs, masonry buildings and pre-cast structures. For RCMRFs, EBFs and RCSWs, the design code is slightly unconservative for low-rise buildings. The outcomes of the study help to arrive at more efficient and cost-effective seismic design of buildings with different characteristics.

Seismic storey drift estimation

1994 ◽  
Vol 21 (6) ◽  
pp. 1081-1083 ◽  
Author(s):  
T. J. Zhu
Keyword(s):  
Dynamic Analysis ◽  
Key Words ◽  
Estimation Procedure ◽  
Building Design ◽  
High Rise ◽  
Moment Resisting Frame ◽  
Drift Estimation ◽  
Frame Buildings ◽  
Moment Resisting ◽  
Code Procedure

The seismic storey drift estimation procedure in the 1990 edition of the National Building Code of Canada is evaluated for ductile moment-resisting frame buildings located in different seismic regions. The evaluation is based on a comparison of the storey drifts estimated from the code procedure with those obtained from the inelastic dynamic analysis of the buildings. The results indicate that the code procedure underestimates storey drift for low-rise ductile moment-resisting frame buildings. It provides good estimates of storey drift for medium- and high-rise ductile moment-resisting frame buildings. The code estimation tends to become conservative as the number of storeys increases. Key words: building, design, drift, seismic, storey.

scholarly journals Overview on the Nonlinear Static Procedures and Performance-Based Approach on Modern Unreinforced Masonry Buildings with Structural Irregularity

Buildings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 147
Author(s):  
Abide Aşıkoğlu ◽  
Graça Vasconcelos ◽  
Paulo B. Lourenço
Keyword(s):  
Earthquake Engineering ◽  
Building Design ◽  
Economic Feasibility ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Design Assessment ◽  
Regular Frame ◽  
Nonlinear Static ◽  
And Performance ◽  
Global Language

Performance-based design plays a significant role in the structural and earthquake engineering community to ensure both safety and economic feasibility. Its application to masonry building design/assessment is limited and requires straightforward rules considering the characteristics of masonry behavior. Nonlinear static procedures mainly cover regular frame system structures, and their application to both regular and irregular masonry buildings require further investigation. The present paper addresses two major issues: (i) the definition of irregularity in masonry buildings, and (ii) the applicability of classical nonlinear static procedures to irregular masonry buildings. It is observed that the irregularity definition is not comprehensive and has different descriptions among the seismic codes as well as among researchers, particularly in the case of masonry buildings. The lack of global language may result in the misuse of the procedures, while adjustments may be essential due to irregularity effects. Therefore, irregularity indices given by different codes and research studies are discussed. Furthermore, an overview of nonlinear static procedures implemented within the framework of the performance-based approach and improvements proposed for its application in masonry buildings is presented.

scholarly journals On the fundamental period of infilled RC frame buildings

2015 ◽  
Vol 54 (6) ◽  
pp. 1175-1200 ◽  
Author(s):  
Panagiotis G. Asteris ◽  
Constantinos C. Repapis ◽  
Liborio Cavaleri ◽  
Vasilis Sarhosis ◽  
Adamantia Athanasopoulou
Keyword(s):  
Fundamental Period ◽  
Rc Frame ◽  
Frame Buildings ◽  
Rc Frame Buildings

Vulnerability of buildings to wildfire

2021 ◽  
Author(s):  
Celine Garlichs ◽  
Michalis Diakakis ◽  
Spyridon Mavroulis ◽  
Sven Fuchs ◽  
Maria Papathoma-Köhle
Keyword(s):  
Construction Material ◽  
Building Design ◽  
Vulnerability Index ◽  
Building Codes ◽  
European Regions ◽  
Physical Vulnerability ◽  
Research Gaps ◽  
Wide Range ◽  
Building Characteristics ◽  
Vulnerability Of Buildings

<p>Recent events worldwide have clearly shown that wildfires pose a serious threat to people and buildings located in the WUI (Wildland-Urban-Interface). In Europe, due to climate change, wildfires are expected to continue affecting areas not only in the Mediterranean but also in other European regions (e.g. alpine and Scandinavian context).  A wide range of tools is available for the assessment of physical vulnerability of buildings to different hazard types including floods, landslides and earthquakes. Yet, to date, vulnerability of buildings to wildfire still remains under-researched. Research gaps in this respect are pointed out in this study and a well-established approach for vulnerability assessment of buildings already used for tsunamis and dynamic flooding is adapted in order to be used for wildfires. The method is based on the development of a vulnerability index using building characteristics (indicators) that contribute to wildfire vulnerability, including construction material, surroundings, building design and surrounding vegetation. The index may be used as a basis for strategies for vulnerability reduction (reinforcement of buildings, building codes), evacuation planning, insurance purposes and resilient reconstruction of affected areas. Preliminary results of an application in Mati (Attica, Greece) based on the data of a wildfire occurred in July 2018 resulting in the death of more than 100 people are presented</p>

Toward a better understanding of the dynamic characteristics of single-storey braced steel frame buildings in Canada

2009 ◽  
Vol 36 (6) ◽  
pp. 969-979 ◽  
Author(s):  
Charles-Philippe Lamarche ◽  
Jean Proulx ◽  
Patrick Paultre ◽  
Martin Turek ◽  
Carlos E. Ventura ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Field Tests ◽  
Steel Frame ◽  
Geometric Parameters ◽  
Fundamental Period ◽  
Mode Shapes ◽  
Fundamental Vibration ◽  
Vibration Period ◽  
Frame Buildings ◽  
Steel Frame Buildings

Single-storey braced steel frame buildings (SSBSFs) are currently the most widely used commercial structures, which include strip malls, power centres, warehouses, small and medium-sized industrial plants. The lateral seismic or wind forces acting on such low-rise structures are usually transferred from a metal roof-deck diaphragm to a system of vertical bracing members. Because these flexible roof diaphragms have a considerable effect on the dynamic response of SSBSFs during an earthquake, they also play an important role in the evaluation of the fundamental vibration period, a key parameter in determining the magnitude of the design seismic forces. It is therefore of utmost importance to reliably predict the fundamental period of SSBSFs. This paper presents the results of a four-year field measurement research project on the dynamic behaviour of SSBSFs. The goal of the project was to create a reliable database for the dynamic characteristics of SSBSFs (periods, mode shapes, and damping) and to find a relationship between them and the geometric parameters (height and plan dimensions). The field tests are described, along with the selected buildings and experimental setup. The measured fundamental periods are then compared to the National building code of Canada (NBCC) empirical equations. A statistical analysis of the data, based on different regression models, yielded new proposed building geometric parameters to be used in simple equations for the prediction of the fundamental period of SSBSFs.

scholarly journals United States building code approach to variations in regional seismicity

2000 ◽  
Vol 33 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Charles A. Kircher
Keyword(s):  
United States ◽  
Seismic Design ◽  
Model Building ◽  
Building Design ◽  
The United States ◽  
Building Codes ◽  
Building Code ◽  
Design Criteria ◽  
Narrow Strip ◽  
Moderate Seismicity

The United States contains regions of greatly varying seismicity ranging from a relatively narrow strip of very high seismicity along coastal California in the West to broad areas of low or moderate seismicity typical of the Central and Eastern United States. The United States currently has three major regional model building codes. While all three codes have traditionally used the concept of seismic zones to identify and distinguish between regions of different seismicity, they have not had a consistent basis for their seismic criteria. Beginning in the year 2000, the three model building codes will merge and become the new International Building Code (IBC) applicable to the whole United States. New seismic design criteria have been developed for the 2000 IBC that now define ground shaking for building design by spectral acceleration contours. This paper describes the background and basis for the new seismic design criteria of the 2000 IBC, and how these criteria address the large variation in seismic hazard across the United States.

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