Dynamic Characteristics of Multi-Story Reinforced Concrete Buildings

2016 ◽  
Vol 249 ◽  
pp. 235-240 ◽  
Author(s):  
Jónas Thór Snaebjornsson ◽  
Eythor Rafn Thorhallsson
Keyword(s):  
Reinforced Concrete ◽  
Natural Frequencies ◽  
Structural Parameters ◽  
Structural Response ◽  
Design Guidelines ◽  
Reinforced Concrete Buildings ◽  
Structural Behaviour ◽  
Measurement Systems ◽  
Concrete Buildings ◽  
International Data

Having a realistic estimate of structural parameters, such as natural frequency and damping is important for design purposes. In this study, available wind and earthquake induced acceleration data from four multi-story reinforced concrete buildings are utilized to examine structural behaviour and system parameters. The buildings measurement systems are described and the recorded structural response data presented. The data stems from two different sources of excitation, i.e. wind and earthquake, and are recorded for various excitation levels and environmental conditions. System identification analyses of the buildings are carried out applying previously verified parametric methods to the recorded data. The natural frequencies and critical damping ratios established from the recordings are compared to values estimated using design guidelines and international data compilations for reinforced concrete structures of similar type. Considerable variability is discovered between the different estimation formulas and the observed natural frequencies of the buildings are found to lie at the upper limit of the prediction formula.

Response of earthquake-resistant reinforced-concrete buildings to blast loadingThis article is one of a selection of papers published in the Special Issue on Blast Engineering.

2009 ◽  
Vol 36 (8) ◽  
pp. 1378-1390 ◽  
Author(s):  
Murat Saatcioglu ◽  
Togay Ozbakkaloglu ◽  
Nove Naumoski ◽  
Alan Lloyd
Keyword(s):  
Reinforced Concrete ◽  
Blast Resistance ◽  
Structural Parameters ◽  
Progressive Collapse ◽  
Structural Response ◽  
Charge Weight ◽  
Blast Loads ◽  
Reinforced Concrete Buildings ◽  
Collapse Potential ◽  
Concrete Buildings

Recent bomb attacks on buildings have raised awareness about the vulnerability of structures to blast effects. The resiliency of structures against blast-induced impulsive loads is affected by structural characteristics that are also important for seismic resistance. Deformability and continuity of structural elements, strength, stiffness, and stability of the structural framing system and resistance to progressive collapse are factors that play important roles on the survivability of buildings under both blast and seismic loads. The significance of these structural parameters on blast resistance of reinforced concrete buildings is assessed through structural analysis. Both local element performance and global structural response are considered while also assessing the progressive collapse potential. The buildings under investigation include 10-storey moment resisting frames with or without shear walls. The blast loads selected consist of different charge-weight and standoff distance combinations. The results are presented in terms of ductility and drift demands. They indicate improved performance of seismic-resistant buildings when subjected to blast loads, in terms of local column performance, overall structural response, and progressive collapse potential.

scholarly journals A New Method to Evaluate the Post-Earthquake Performance and Safety of Reinforced Concrete Structural Frame Systems

2020 ◽  
Vol 5 (2) ◽  
pp. 16
Author(s):  
Foteini Konstandakopoulou ◽  
George Hatzigeorgiou ◽  
Konstantinos Evangelinos ◽  
Thomas Tsalis ◽  
Ioannis Nikolaou
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Structural Parameters ◽  
Permanent Deformation ◽  
Nonlinear Behavior ◽  
Building Structures ◽  
Reinforced Concrete Buildings ◽  
Concrete Buildings ◽  
Residual Displacements ◽  
Seismic Displacements

This study examines the relation between maximum seismic displacements and residual displacements for reinforced concrete building structures. In order to achieve a reliable relationship between these critical structural parameters for the seismic performance of concrete buildings, an extensive parametric study is conducted by examining the nonlinear behavior of numerous planar framed structures. In this work, dynamic inelastic analyses are executed to investigate the seismic behavior of two sets of frames. The first group consists of four planar frames which have been designed for seismic and vertical loads according to modern structural codes while the second group also consists of four frames, which have been designed for vertical loads only, in order to examine older structures that have been designed using codes with inadequate seismic provisions. These two sets of buildings are subjected to various earthquakes with different amplitudes in order to develop a large structural response databank. On the basis of this wide-ranging parametric investigation, after an appropriate statistical analysis, simple empirical expressions are proposed for a straightforward and efficient evaluation of maximum seismic displacements of reinforced concrete buildings structures from their permanent deformation. Permanent displacements can be measured in-situ after strong ground motions as a post-earthquake assessment. It can be concluded that the measure of permanent deformation can be efficiently used to estimate the post-seismic performance level of reinforced concrete buildings.

scholarly journals Impact of Revised Code NBC105 on Assessment and Design of Low Rise Reinforced Concrete Buildings in Nepal

2021 ◽  
Vol 16 (1) ◽  
pp. 1-5
Author(s):  
Jagat K. Shrestha ◽  
Nirajan Paudel ◽  
Bishal Koirala ◽  
Binod R. Giri ◽  
Adarsha Lamichhane
Keyword(s):  
Reinforced Concrete ◽  
Residential Buildings ◽  
Structural Response ◽  
Building Codes ◽  
Seismic Load ◽  
Base Shear ◽  
Reinforced Concrete Buildings ◽  
Concrete Buildings ◽  
The Government ◽  
The Impact

Gorkha Earthquake in 2015 has impacted considerably in the design and construction of buildings in Nepal. Strength and Safety of life and constructions have become the prime concerns of the government and the public. Regulation is required to achieve the strength and safety in the constructions. Hence, a need for revision of building codes has been felt and Nepal Building Code, NBC105 has been revised. This paper presents the impact of the revised code on seismic load estimation for low rise reinforced concrete buildings. For the assessment of the impact linear and non- linear static and linear dynamic analysis of reinforced concrete residential buildings of two storey and four Storey has been taken subjected to Indian Standard Codes IS 1893: 2002, IS 1893:2016, Nepal Building Codes NBC 105: 1994 and NBC 105: 2020. The buildings were modeled and analyzed in SAP2000. The response of the buildings such as time period, base shear, drifts, and storey forces from the application of the four codes was compared. The comparison of the results shows that the structural response of the building under the revised NBC105:2020 is 60% to 65% higher compared to the previous code NBC105:1994.

scholarly journals EVALUATION OF VIBRATION-BASED GLOBAL STRUCTURAL HEALTH MONITORING METHOD FOR MEDIUM-RISE BUILDINGS

2021 ◽  
Vol 1 ◽  
pp. 55-61
Author(s):  
Liga Gaile ◽  
Ivars Radins
Keyword(s):  
Reinforced Concrete ◽  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Natural Frequencies ◽  
Construction And Demolition Waste ◽  
Structural Safety ◽  
Reinforced Concrete Buildings ◽  
Monitoring Method ◽  
Concrete Buildings ◽  
Structural Health

The automated monitoring of a building’s structural health during its exploitation is a way to extend its design life without compromising structural safety.  In turn, it helps increase the rate of building renovation works compared to demolition works, which reduces future construction and demolition waste levels.This research explores the vibration-based global monitoring method application to structurally stiff medium-rise reinforced concrete buildings by analysing predicted building vibration amplitudes and spectrum under regular city traffic excitation. These predictions are based on the results obtained from finite element calculations of building models with variated structural stiffness and inertial mass of the building.Regular traffic-generated ground frequency spectrum differs from the first natural frequencies of medium-rise reinforced concrete buildings, and the vibration energy is low. Nevertheless, it is found that the structural identification of such building dynamic parameters is still possible, particularly natural frequencies. It was found that the ratio between fundamental frequency for the fixed base model of the building and elastic spring foundation model is the decisive parameter for selecting the building part to be monitored. Structural health monitoring vibration-based methods are also a promising technology for medium-rise mass house buildings when tailored according to some damage sensitive feature.  

scholarly journals Irregularity of the Distribution of Masonry Infill Panels and Its Effect on the Seismic Collapse of Reinforced Concrete Buildings

2021 ◽  
Vol 11 (18) ◽  
pp. 8691
Author(s):  
Juan Carlos Vielma ◽  
Roberto Aguiar ◽  
Carlos Frau ◽  
Abel Zambrano
Keyword(s):  
Reinforced Concrete ◽  
Structural Response ◽  
Practical Reasons ◽  
Reinforced Concrete Buildings ◽  
Masonry Infill ◽  
Concrete Buildings ◽  
Infill Panels ◽  
Open Plan ◽  
Collapsed Buildings ◽  
The City

On 16 April 2016, an earthquake of Mw 7.8 shook the coast of Ecuador, causing the destruction of buildings and a significant number of casualties. Following a visit by the authors to the city of Portoviejo during the debris removal and recovery stage, it was noted that several reinforced concrete buildings located on corners had collapsed in the central part of the city. These buildings were characterized by the presence of masonry at the edges of the buildings but not between the two mostly open-plan facades on the corner for practical reasons. This article reviews the effect of masonry infill panels on the seismic response of reinforced concrete structures. For this, a model that contains the geometric and mechanical characteristics typical of collapsed buildings was generated and subjected to nonlinear analysis, with both static and dynamic increments. The results show the clear influence of the masonry infill panels on the structural response through the torsional behavior that is reflected in the evolution of the floor rotations. Finally, dynamic incremental analysis is used to obtain the collapse fragility curve of the building, and a new damage measure based on floor rotations is proposed.

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