scholarly journals Dynamic Monitoring of a Mid-Rise Building by Real-Aperture Radar Interferometer: Advantages and Limitations

2020 ◽  
Vol 12 (6) ◽  
pp. 1025
Author(s):  
Rodrigo E. Alva ◽  
Luis G. Pujades ◽  
Ramón González-Drigo ◽  
Guido Luzi ◽  
Oriol Caselles ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Structural Response ◽  
Ambient Vibration ◽  
Dynamic Monitoring ◽  
In Situ Techniques ◽  
Fundamental Frequencies ◽  
Time Histories ◽  
Reported Data ◽  
Real Aperture Radar ◽  
Aperture Radar

In this paper, remote and in situ techniques to estimate the dynamic response of a building to ambient vibration are reported: data acquired through a real-aperture radar (RAR) interferometer and conventional accelerometers are analyzed. A five-story reinforced concrete housing building, which was damaged during the May 11th 2011 Lorca (Spain) earthquake, is used as a case study. The building was monitored using both types of instruments. The dynamic properties of the building are estimated first taking acceleration measurements using a set of 10 high-precision accelerometers installed on the roof of the building. Further, the displacement–time histories, recorded with the RAR device pointing to a corner of the building, are analyzed. Then, the ability and shortcomings of RAR measurements to deal with the fundamental frequencies of vibration of the structure are investigated. The advantages and limitations of from-inside (accelerometric) and from-outside (RAR) measurements are highlighted and discussed. A relevant conclusion is that, after strong earthquakes, RAR may be an interesting and useful tool, as it allows surveying the structural response of mid-rise buildings remotely, without the need to enter the structures, which may be dangerous for inspectors or technicians in cases of severely damaged buildings. Given that the instrumented building suffered significant damage, the ability of these kinds of measurements to detect damage is also discussed.

Structural monitoring of a curve portion of an elevated railroad including the effects of the 19 September 2017 earthquake

2020 ◽  
Vol 36 (2_suppl) ◽  
pp. 262-287
Author(s):  
David Murià-Vila ◽  
Baruo Daniel Aldama-Sánchez ◽  
Miguel Ángel García-Illescas ◽  
Abraham Roberto Sánchez-Ramírez ◽  
Santiago Loera
Keyword(s):  
Structural Integrity ◽  
Soft Soil ◽  
Structural Response ◽  
Field Tests ◽  
Warning System ◽  
Ambient Vibration ◽  
Great Earthquake ◽  
Seismic Events ◽  
Fundamental Frequencies ◽  
Design Values

This article presents the most significant structural response parameters of a railway system analyzed with data gathered during 5 years. The structure is the instrumented curved portion of an elevated railroad that consists of a simply supported beam resting on cantilever columns on soft soil. A monitoring system was implemented to determine, within a few minutes, a preliminary structural state analyzing ambient vibration or seismic events. To assess the state of health of the structure, the response obtained from the seismic events, applying the proposed methodology, is compared with that obtained from controlled field tests conducted at the end of its construction and compared with design values. The monitoring system’s results showed minimal frequency variations caused by external works and a transitory variation of the fundamental frequencies during the 19 September 2017 great earthquake that, however, did not affect the structural integrity. The warning system showed acceptable performance, and only suggested checking the support beam-column condition.

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 LONG-TERM DYNAMIC MONITORING OF THE HISTORICAL MASONRY FAÇADE: THE CASE OF PALAZZO DUCALE IN VENICE, ITALY

2017 ◽  
Vol IV-2/W2 ◽  
pp. 187-193 ◽  
Author(s):  
J. Noh ◽  
S. Russo
Keyword(s):  
Dynamic Properties ◽  
Masonry Wall ◽  
Dynamic Responses ◽  
Ambient Vibration ◽  
Dynamic Monitoring ◽  
Dynamic Identification ◽  
Data Set ◽  
Vibration Signature ◽  
Historical Masonry

Long-term dynamic monitoring of the masonry façade of Palazzo Ducale known as Doge’s palace in Venice, Italy was performed from September 2010 to October 2012. This article demonstrates the results of preliminary analysis on the data set of the first 12-month long monitoring campaign for out-of-plumb dynamic responses of the medieval façade of the monument. The aim of the analysis of the dynamic signals is to validate the data set and investigate dynamic characteristics of the vibration signature of the historical masonry wall in the long-term. <i>Palazzo Ducale</i> is a heavily visited heritage due to its high cultural importance and architectural value. Nevertheless, little is known about the dynamic behaviour of the double-leaf masonry façade. In this study, the dynamic properties of the structure are presented by dynamic identification carried out with the effect of the ambient vibration measured at four different locations on the façade and portico level. The trend and intensity of the vibration at each measurement locations are identified over the year. In addition, the issue on eliminating the noise blended in the signals for reliable analysis are also discussed.

Health monitoring and safety evaluation of bridge dynamic load with a ground-based real aperture radar

Survey Review ◽  
2021 ◽  
pp. 1-15
Author(s):  
Sichun Long ◽  
Wenting Liu ◽  
Jinyu Ma ◽  
Aixia Tong ◽  
Wenhao Wu ◽  
...  
Keyword(s):  
Health Monitoring ◽  
Dynamic Load ◽  
Safety Evaluation ◽  
Real Aperture Radar ◽  
Aperture Radar

Satellite-based real aperture radar image spectrum simulation with Wen's wave spectrum

2009 ◽  
Author(s):  
Lin Ren ◽  
Le Yang ◽  
Zhihua Mao ◽  
Jianyu Chen ◽  
Delu Pan
Keyword(s):  
Wave Spectrum ◽  
Radar Image ◽  
Spectrum Simulation ◽  
Real Aperture Radar ◽  
Aperture Radar

Angular Superresolution of Real Aperture Radar Using Online Detect-Before-Reconstruct Framework

2021 ◽  
pp. 1-1
Author(s):  
Deqing Mao ◽  
Jianyu Yang ◽  
Yongchao Zhang ◽  
Weibo Huo ◽  
Jiawei Luo ◽  
...  
Keyword(s):  
Real Aperture Radar ◽  
Aperture Radar

scholarly journals Dynamics and Protein–Solvent Interactions of Hemoglobin in T and R Quaternary Conformation

2002 ◽  
Vol 16 (3-4) ◽  
pp. 227-233 ◽  
Author(s):  
Chiara Caronna ◽  
Antonio Cupane
Keyword(s):  
Quaternary Structure ◽  
Dynamic Properties ◽  
Low Frequency ◽  
Helical Structure ◽  
Blue Shift ◽  
Peak Frequency ◽  
The Other ◽  
Solvent Interactions ◽  
Reported Data ◽  
Increasing Temperature

In this work we report the thermal behaviour of the amide I′ band of carbonmonoxy and deoxy hemoglobin in 65% v/v glycerolD8/D2O solutions and in the temperature interval 10–295 K. Following recent suggestions in the literature, we analyze the amide I′ band in terms of two components, one at about 1630 cm−1and the other at about 1650 cm−1, that are assigned to solvent‒exposed and buried α‒helical regions, respectively.For deoxy hemoglobin (in T quaternary structure) both components are narrower with respect to carbonmonoxy hemoglobin (in R quaternary structure), while the peak frequency blue shift observed, upon increasing temperature, for the component at about 1630 cm−1is smaller. The reported data provide evidence of the dependence of hemoglobin dynamic properties upon the protein quaternary structure and suggest a more compact α‒helical structure of hemoglobin in T conformation, with reduced population of low‒frequency modes involving the solvent and protein.

Effects of Nonlinear Riser-Soil Interaction Model on Fatigue Design of Steel Catenary Riser Under Random Waves

2017 ◽  
Author(s):  
Mehrdad Kimiaei
Keyword(s):  
Oil And Gas ◽  
Structural Response ◽  
Interaction Model ◽  
Nonlinear Behavior ◽  
Random Waves ◽  
Steel Catenary Riser ◽  
Oil And Gas Fields ◽  
Fatigue Design ◽  
Time Histories ◽  
Main Components

Steel Catenary Risers (SCRs) are one of the main components in development of oil and gas fields in deep waters. Fatigue design of SCRs in touch down zone (TDZ) is one of the main engineering challenges in design of riser systems. Nonlinear riser-soil interaction models have recently been introduced and used widely in advanced structural analysis of SCRs. Due to hysteretic nonlinear behavior of the soil, SCR system will show different structural response under different loading time histories. This paper investigates the effects of nonlinear riser-soil interaction in the TDZ on fatigue performance of an example SCR subjected to randomly generated waves. Sensitivity of fatigue life of the system, location of the critical node and the maximum stress range to different wave realizations and different soil types are discussed in detail.

Coupled torsional dynamic analysis of a multistory building

1973 ◽  
Vol 63 (3) ◽  
pp. 1025-1039
Author(s):  
Bruce M. Douglas ◽  
Thomas E. Trabert
Keyword(s):  
Ground Motion ◽  
Degrees Of Freedom ◽  
Seismic Waves ◽  
Structural Response ◽  
Tall Buildings ◽  
Strong Motion ◽  
Ambient Vibration ◽  
Simultaneous Application ◽  
Vibration Data ◽  
Horizontal Ground Motion

abstract The coupled bending and torsional vibrations of a relatively symmetric 22-story reinforced concrete building in Reno, Nevada are studied. Analytical results are compared with observations obtained during the nuclear explosion FAULTLESS and to ambient vibration data. The fundamental periods of vibration observed during FAULTLESS were (TNS = 1.42, TEW = 1.81, TTORSION = 1.12 sec), and the calculated periods were (TNS = 2.14, TEW = 2.07, TTORSION = 1.90 sec). It was estimated that between 25 and 45 per cent of the total available nonstructural stiffness was required to explain the differences in the observed and calculated fundamental periods. Each floor diaphragm in the system was allowed three degrees of freedom-two translations and a rotation. It was found that coupled torsional motions can influence the response of structural elements near the periphery of the structure. Strong-motion structural response calculations comparing the simultaneous use of both components of horizontal ground motion to a single component analysis showed that the simultaneous application of both components of ground motion can significantly alter the response of lateral load-carrying elements. Differences of the order of 45 per cent were observed in the frames near the ends of the structure. Also, it was shown that the overall response of tall buildings is sensitive not only to the choice of input ground motion but also to the orientation of the structure with respect to the seismic waves.

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