Analysis of a damaged 12-storey frame-wall concrete building during the 2010 Haiti earthquake — Part II: Nonlinear numerical simulations

2013 ◽  
Vol 40 (8) ◽  
pp. 803-814 ◽  
Author(s):  
Benoit Boulanger ◽  
Patrick Paultre ◽  
Charles-Philippe Lamarche
Keyword(s):  
Structural Damage ◽  
Numerical Models ◽  
Dynamic Properties ◽  
Shear Walls ◽  
Element Model ◽  
Companion Paper ◽  
Ambient Vibration ◽  
Wall Structure ◽  
Haiti Earthquake ◽  
Concrete Building

After the 2010 Haiti earthquake, which destroyed a significant part of the seismically vulnerable city of Port-au-Prince, the country’s capital, a 12-storey reinforced concrete building that behaved well was investigated to understand its dynamic response. This paper completes the experimental work presented in a companion paper, in which the dynamic properties of the building were obtained from ambient vibration tests, and from which a finite-element model was updated. This paper’s main objectives are: (i) to understand the causes that led to the observed structural damage; and (ii) to estimate the likely seismic excitation at the site of the building. Several nonlinear analyses involving various ground motion intensities were conducted and the results were compared with the damage reported during the on-site survey. The numerical models reproduced the observed damages well and helped to explain them. The overall response of the mixed stiff frame–wall structure was clearly dominated by the high stiffness of the shear walls, showing that this type of structural system helps in keeping reasonable interstorey drift levels. Overall, the building’s structure seems to have responded linearly to all the ground motions investigated, but deformation demands imposed to the frame by the shear walls lead to local damages.

scholarly journals Comparison of different finite element model updates based on experimental onsite testing: the case study of San Giovanni in Macerata

2021 ◽  
Author(s):  
Carlo Baggio ◽  
Valerio Sabbatini ◽  
Silvia Santini ◽  
Claudio Sebastiani
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Numerical Models ◽  
Dynamic Properties ◽  
Structural Parameters ◽  
Element Model ◽  
Ambient Vibration ◽  
Geotechnical Investigations ◽  
Historic Structures

AbstractUnderstanding the behavior of historic structures that have undergone structural changes, restorations, and damage over time is still a significant challenge for structural engineers, particularly in those countries subject to high seismic risk, such as Italy. The study of built heritage for its prevention and conservation is an active research topic, due to the numerous uncertainties present in historic structures. Finite element modelling has become the most common and accessible method to study the behavior of complex masonry structures, however, the gap between numerical and experimental analysis may lead to erroneous results. Model updating techniques can reduce the discrepancy between the behavior of the numerical models and the testing results. The goal of this work is to illustrate a methodology to integrate the information derived from local, global, and geotechnical investigations into the finite element model of the masonry historical church of San Giovanni in Macerata, considering the Douglas–Reid model updating method. The PRiSMa laboratory of Roma Tre University carried out local investigations such as sonic tomography, video endoscopy and double flat jack tests, along with five ambient vibration tests that were processed through the operational modal analysis to extrapolate the dynamic properties of the building (modal frequency, modal shape vector and modal damping). The combined use of global, local and geotechnical information implemented in the methodology effectively reduced the uncertainties of the model and led the refinement and validation of the most relevant structural parameters.

scholarly journals Experimental modal identification and fem updating of a seven story isolated educational building

2019 ◽  
Vol 29 (2) ◽  
Author(s):  
Rony Reategui ◽  
Estefanía Bossus ◽  
Mauricio Gonzales ◽  
Diego Villagomez ◽  
Rafael Aguilar
Keyword(s):  
Degrees Of Freedom ◽  
Numerical Models ◽  
Dynamic Properties ◽  
Structural Response ◽  
Experimental Tests ◽  
Cost Effective ◽  
Element Model ◽  
Modal Identification ◽  
Ambient Vibration ◽  
National Regulation

The construction of isolated structures is increasing in recent decades in seismic countries. In Peru, the national regulation indicates that important buildings such as hospitals located in areas of high seismic risk must incorporate isolation systems to reduce structural and nonstructural loss. These systems protect the main structure from the effects of a seismic event by separating its base from the earth movement and by reducing the relative displacements and accelerations between adjacent stories. In the structural design process of buildings and seismic protection systems, having numerical models that properly represent the real behavior of the buildings is of high importance. In this context, experimental modal tests represents an attractive cost-effective non-destructive tool to obtain an accurate characterization of the experimental structural response. This paper presents the experimental tests carried out in a base-isolated educational building built in 2014 that has seven stories and three basements with a total built area of around 7500 m2. Data acquisition was accomplished with autonomous units (acquisition system and transducers incorporated in a single unit) whose versatility allowed measuring a significant number of degrees of freedom in a limited amount of time. The dynamic properties experimentally identified were used to calibrate the finite element model of the building. The results showed that the design model approximates correctly to the experimentally identified ambient vibration response when considering rigid supporting conditions as well as the interaction of partitioning elements such as walls and parapets.

scholarly journals Determination of Period of RC Buildings by the Ambient Vibration Method

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Mehmet Inel ◽  
Hayri Baytan Ozmen ◽  
Bayram Tanik Cayci
Keyword(s):  
Natural Vibration ◽  
Dynamic Properties ◽  
Shear Walls ◽  
Vibration Signal ◽  
Analytical Models ◽  
Ambient Vibration ◽  
Seismic Behaviour ◽  
Infill Wall ◽  
Infill Walls ◽  
Vibration Period

Determining the dynamic properties of structures is important for understanding their seismic behaviour. Ambient vibration signal measurement is one of the approaches used to determine the period of structures. Advantages of this method include the possibility of taking real-time records and presenting nondestructive and rapid solutions. In this study, natural vibration periods are calculated by taking ambient vibration signal records from 40 buildings. The height of the building, infill wall effect, presence of seismic retrofit, and presence of damage are taken into consideration, and their effects on natural vibration periods are investigated. Moreover, the results are compared with the analytical methods to reveal the differences. A significant correlation between the period and height of the building is observed. It is seen that the natural vibration periods of the buildings decrease by 7% to 30% (15% on average) due to infill wall contribution. However, the efficiency of infill walls decreases as the building height increases. Another significant result is that adding shear walls substantially decreases the vibration period values by 23% to 33% with respect to the shear wall ratio. When the analytical estimates and measured building period results are compared, it is seen that analytical models have closer period estimates before infill walls are implemented. The limited data in scope of the study suggest that significant differences may present in the analytical and measured periods of the buildings due to infill wall contributions.

The Influence of Structural Damage on the Vibration Characteristics of Shear-Wall Buildings

2012 ◽  
Vol 193-194 ◽  
pp. 1216-1220 ◽  
Author(s):  
Kai Huang ◽  
Li Hua Zou ◽  
Jian Mei Chen
Keyword(s):  
Plastic Zone ◽  
Structural Damage ◽  
Pushover Analysis ◽  
Shear Walls ◽  
Shear Wall ◽  
Internal Force ◽  
Vibration Characteristics ◽  
Wall Structure ◽  
Wall Structures ◽  
The Continuum

To understand the higher modal effect on the accuracy of pushover analysis for shear wall structure, the influence of damage on the vibration characteristics of shear-wall structures is investigated. Employing the continuum technique, the shift of modal shapes and periods for the first three modes is obtained when the plastic zone exists in the bottom of the shear wall. It can be conclude that plastic zone may enhance the higher modal effect when the internal force responses of shear walls are considered. The higher modal contribution can not be neglected when computing the nonlinear earthquake responses of shear wall structures.

Dynamic characteristics of Canada's Parliament Hill towers from ambient vibrations and recorded earthquake data

2021 ◽  
Vol 48 (1) ◽  
pp. 16-25
Author(s):  
Michal Kolaj ◽  
John Adams
Keyword(s):  
Structural Damage ◽  
Nonlinear Response ◽  
Dynamic Properties ◽  
Ground Motions ◽  
Ambient Vibration ◽  
The South ◽  
Vibration Data ◽  
South West ◽  
Baseline Values ◽  
Strong Ground

The dynamic properties of Parliament Hill’s buildings (Ottawa, Canada) are of particular interest due to their important heritage value and because of the seismic retrofit project currently underway. To measure the dynamic properties directly, ambient vibration data were collected within the Peace Tower of Centre Block and the South-West Tower of East Block and processed together with weak to strong ground motions from six earthquakes. Both datasets found the fundamental mode to be 1.0–1.15 Hz for the Peace Tower and 2 Hz for the South-West Tower. The 2010 magnitude 5 Val-des-Bois earthquake induced peak accelerations of 49% g and 18% g in the top floors of the Peace and South-West towers, respectively, triggering a nonlinear response, causing the frequencies of the dominant modes to be reduced by 10%–15%. The reduction in frequency was temporary and the frequencies returned to baseline values, suggesting that there was no permanent structural damage.

scholarly journals Identification, Model Updating, and Response Prediction of an Instrumented 15-Story Steel-Frame Building

2006 ◽  
Vol 22 (3) ◽  
pp. 781-802 ◽  
Author(s):  
Derek Skolnik ◽  
Ying Lei ◽  
Eunjong Yu ◽  
John W. Wallace
Keyword(s):  
Structural Damage ◽  
Model Updating ◽  
Three Dimensional ◽  
Response Prediction ◽  
Element Model ◽  
Ambient Vibration ◽  
Mode Shapes ◽  
Northridge Earthquake ◽  
Vibration Data ◽  
Modal Properties

Identification of the modal properties of the UCLA Factor Building, a 15-story steel moment-resisting frame, is performed using low-amplitude earthquake and ambient vibration data. The numerical algorithm for subspace state-space system identification is employed to identify the structural frequencies, damping ratios, and mode shapes corresponding to the first nine modes. The frequencies and mode shapes identified based on the data recorded during the 2004 Parkfield earthquake ( Mw=6.0) are used to update a three-dimensional finite element model of the building to improve correlation between analytical and identified modal properties and responses. A linear dynamic analysis of the updated model excited by the 1994 Northridge earthquake is performed to assess the likelihood of structural damage.

scholarly journals Identification of Historical Veziragasi Aqueduct Using the Operational Modal Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
E. Ercan ◽  
A. Nuhoglu
Keyword(s):  
Modal Analysis ◽  
Natural Frequencies ◽  
Model Updating ◽  
Dynamic Properties ◽  
Dynamic Test ◽  
Element Model ◽  
Operational Modal Analysis ◽  
Modal Identification ◽  
Ambient Vibration ◽  
Mode Shapes

This paper describes the results of a model updating study conducted on a historical aqueduct, called Veziragasi, in Turkey. The output-only modal identification results obtained from ambient vibration measurements of the structure were used to update a finite element model of the structure. For the purposes of developing a solid model of the structure, the dimensions of the structure, defects, and material degradations in the structure were determined in detail by making a measurement survey. For evaluation of the material properties of the structure, nondestructive and destructive testing methods were applied. The modal analysis of the structure was calculated by FEM. Then, a nondestructive dynamic test as well as operational modal analysis was carried out and dynamic properties were extracted. The natural frequencies and corresponding mode shapes were determined from both theoretical and experimental modal analyses and compared with each other. A good harmony was attained between mode shapes, but there were some differences between natural frequencies. The sources of the differences were introduced and the FEM model was updated by changing material parameters and boundary conditions. Finally, the real analytical model of the aqueduct was put forward and the results were discussed.

scholarly journals The Health Monitoring Method of Concrete Dams Based on Ambient Vibration Testing and Kernel Principle Analysis

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Lin Cheng ◽  
Jie Yang ◽  
Dongjian Zheng ◽  
Bo Li ◽  
Jie Ren
Keyword(s):  
Health Monitoring ◽  
Structural Damage ◽  
Dynamic Properties ◽  
Ambient Vibration ◽  
Modal Parameters ◽  
Observation System ◽  
Concrete Dams ◽  
Vibration Testing ◽  
Monitoring Method ◽  
Ambient Vibration Testing

The ambient vibration testing (AVT) measurement of concrete dams on full-scale can show the practical dynamic properties of structure in the operation state. For most current researches, the AVT data is generally analyzed to identify the structural vibration characteristics, that is, modal parameters. The identified modal parameters, which can provide the global damage information or the damage location information of structure, can be used as the basis of structure health monitoring. Therefore, in this paper, the health monitoring method of concrete dams based on the AVT is studied. The kernel principle analysis (KPCA) based method is adopted to eliminate the effect of environmental variables and monitor the health of dam under varying environments. By taking full advantage of the AVT data obtained from vibration observation system of dam, the identification capabilities and the warning capabilities of structural damage can be improved. With the simulated AVT data of the numerical model of a concrete gravity dam and the measured AVT data of a practical engineering, the performance of the dam health monitoring method proposed in this paper is verified.

scholarly journals Experimental and Numerical Investigation on Dynamic Properties and Human-Induced Vibrations of an Asymmetric Steel-Plated Stress-Ribbon Footbridge

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Yi Zhang ◽  
Wei He ◽  
Jiewen Zhang ◽  
Hua Dong
Keyword(s):  
Dynamic Properties ◽  
Element Model ◽  
Ambient Vibration ◽  
Subspace Identification ◽  
Stochastic Subspace Identification ◽  
Deck Panels ◽  
Single Person ◽  
Ambient Vibration Testing ◽  
Measurement Results ◽  
Comprehensive Study

This paper presents a comprehensive study on dynamic properties and human-induced vibrations of a slender asymmetric steel-plated stress-ribbon footbridge via both experimental and analytical methods. Bridge modal test was conducted using both ambient vibration testing and impact methods. Modal properties of the bridge were identified based on stochastic subspace identification and peak-pick techniques. Results show that the bridge is characterized by closely spaced modes with low natural frequencies and small damping ratios (<0.002). A sophisticated finite element model that incorporates pretension of the stress ribbon and contribution of deck panels is developed and proven to be capable of reflecting the main dynamic characteristics of the bridge. Human-induced vibrations were measured considering synchronization cases, including single-person and small group walking as well as random walking cases. A theoretical model that takes into account human-structure interaction was developed, treating the single walking person as an SDOF system with biomechanical excited force. The validity of the model was further verified by measurement results.

Dynamic Characteristics Analysis of Large Space Shear Wall

2012 ◽  
Vol 166-169 ◽  
pp. 400-404
Author(s):  
Li Jian Zhou ◽  
Jin Zhou He ◽  
Jing Huang
Keyword(s):  
Dynamic Properties ◽  
Shear Walls ◽  
Shear Wall ◽  
Wall Structure ◽  
Large Space ◽  
Element Analysis ◽  
Characteristics Analysis ◽  
Analysis Models ◽  
Dynamic Characteristics Analysis ◽  
Different Thickness

This paper select the appropriate calculation and analysis models and examples, using finite element analysis software ANSYS to compare and analyze the dynamic properties of three large space shear walls of different thickness. The result indicated: the effects of the large space shear wall structure to torsion with the increase of wall thickness.

Sign in / Sign up

Export Citation Format

Share Document