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.

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.

Structural System Identification of Elevated Steel Water Tank Using Ambient Vibration Test and Calibration of Numerical Model

2020 ◽  
Vol 20 (10) ◽  
pp. 2071010
Author(s):  
Mohammad Alembagheri ◽  
Maria Rashidi ◽  
Mohammad Seyedkazemi
Keyword(s):  
System Identification ◽  
Numerical Model ◽  
Dynamic Properties ◽  
Ambient Vibration ◽  
Water Tank ◽  
Ambient Vibration Test ◽  
Vibration Data ◽  
Steel Material ◽  
Ambient Vibration Testing ◽  
Structural System Identification

This research aims to investigate the feasibility of using ambient vibration testing for system identification of an elevated water tank. To identify the natural dynamic properties, the experimental study is carried out on an elevated steel water tank located in Tehran. The tank is instrumented with a sensitive velocimeter sensor (microtremor), and the ambient velocity of the tank is recorded for 30[Formula: see text]min in three orthogonal axes. Employing the peak-picking method in the frequency domain, the fundamental frequency of the tank is determined as about 1.9[Formula: see text]Hz. Then, the numerical model of the tank is generated and calibrated based on the obtained data. In the primary modeling, the values of natural frequencies of the tank are in good agreement with the results of the ambient vibration data. This finding is judged to be reasonable considering no clear sign of corrosion in the steel material.

On the Seismic Response of the Faculty of Architecture and Engineering Building at Tohoku University

2016 ◽  
Vol 32 (1) ◽  
pp. 523-545 ◽  
Author(s):  
Ying Wang ◽  
Enrique Villalobos ◽  
Santiago Pujol ◽  
Hamood Al-Washali ◽  
Kazuki Suzuki ◽  
...  
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Structural Damage ◽  
Ground Motions ◽  
Strong Ground Motions ◽  
First Motion ◽  
Strong Ground

The Faculty of Architecture and Engineering Building at Tohoku University survived two strong ground motions. This is not surprising because the structure was stiff and strong. What is surprising is that the first ground motion did not cause severe structural damage but the second one caused so much structural damage that the building had to be evacuated and demolished. The damage occurred despite two key facts: (1) the intensities of the mentioned ground motions are understood to have been similar and (2) the building was strengthened after the first motion (and before the second) following stringent standards.

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 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.

Structural damage diagnosis under varying environmental conditions with very limited measurements

2020 ◽  
Vol 31 (5) ◽  
pp. 665-686
Author(s):  
J Prawin ◽  
K Lakshmi ◽  
A Rama Mohan Rao
Keyword(s):  
Environmental Conditions ◽  
Structural Damage ◽  
Strain Energy ◽  
Tamil Nadu ◽  
Ambient Vibration ◽  
Subspace Analysis ◽  
Vibration Data ◽  
Second Stage ◽  
Excitation Frequencies ◽  
The Relationship

In this article, we present a damage diagnostic scheme with very limited measurements. The influence of environmental and operational variabilities has been considered in the present investigations apart from measurement noise. We employ null subspace analysis in the first stage to confirm the presence of damage using ambient vibration data through online monitoring. Once the presence of damage is established, in the second stage, through offline monitoring, we use the zero strain energy node concept to localize damage through inference from the set of excitation frequencies at which the structure with localized damage behaves like a healthy structure. The proposed technique requires the numerical model of the healthy structure to establish the relationship between zero strain energy nodes and excitation frequencies. In order to evaluate the proposed technique, numerical simulation studies are carried out initially on a simple beam-like structure and later considering a more practical example of the bridge existing across the Amaravathi River in Tamil Nadu, India. These investigations are subsequently complemented with an experimental study on steel I beam girder. It can be concluded from the investigations that the proposed approach is capable of detecting and localizing multiple and also subtle damages under varying environmental conditions with very limited noise-contaminated measurements.

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