A proposed method for the detection of steel moment connection fractures using high-frequency, transient accelerations

Rodgers, Janise E.; Çelebi, Mehmet

doi:10.3133/ofr20051375

Cited by 3 publications

(6 citation statements)

References 11 publications

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“…It does not depend on recording the transient signal during the damage event itself. This is different from the few unique exceptions such as the studies done by Dunand et al (2004) and Rodgers and Celebi (2005), which involved analysis of transient signals recorded during damaging shaking caused by the 1994 Northridge earthquake.…”

Section: Introductionmentioning

confidence: 88%

Detection of Building Damage Using Helmholtz Tomography

Kohler

Allam

Massari

et al. 2018

Bulletin of the Seismological Society of America

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High-rise buildings with dense permanent installations of continuously recording accelerometers offer a unique opportunity to observe temporal and spatial variations in the propagation properties of seismic waves. When precise, floor-by-floor measurements of frequency-dependent travel times can be made, accurate models of material properties (e.g., stiffness or rigidity) can be determined using seismic tomographic imaging techniques. By measuring changes in the material properties, damage to the structure can be detected and localized after shaking events such as earthquakes. Here, seismic Helmholtz tomography is applied to simulated waveform data from a high-rise building, and its feasibility is demonstrated. A 52-story dual system building-braced-frame core surrounded by an outrigger steel moment frame-in downtown Los Angeles is used for the computational basis. It is part of the Community Seismic Network and has a three-component accelerometer installed on every floor. A finite-element model of the building based on structural drawings is used for the computation of synthetic seismograms for 60 damage scenarios in which the stiffness of the building is perturbed in different locations across both adjacent and distributed floors and to varying degrees. The dynamic analysis loading function is a Gaussian pulse applied to the lowest level fixed boundary condition, producing a broadband response on all floors. After narrowband filtering the synthetic seismograms and measuring the maximum amplitude, the frequency-dependent travel times and differential travel times are computed. The travel-time and amplitude measurements are converted to shear-wave velocity at each floor via the Helmholtz wave equation whose solutions can be used to track perturbations to wavefronts through densely sampled wavefields. These results provide validation of the method's application to recorded data from real buildings to detect and locate structural damage using earthquake, explosion, or ambient seismic noise data in near-real time. Electronic Supplement: Table and figures describing nine additional velocity imaging tests that were run using the same procedure described in the main article.

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Section: Introductionmentioning

confidence: 88%

Detection of Building Damage Using Helmholtz Tomography

Kohler

Allam

Massari

et al. 2018

Bulletin of the Seismological Society of America

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“…The second case study is a 15‐story steel building referred to as Sherman Oaks Ventura Blvd. #6 (Station Number: 2C014) as reported in . A complete description of the building including a careful evaluation of its dynamic response during the 1994 Northridge earthquake is available in .…”

Section: Evaluation Of the Proposed Methodsmentioning

confidence: 99%

“…The lateral system of this building consists of steel MRFs installed in the perimeter and around the core of the building. Similarly to the 15‐story steel building discussed in Section 3.2, the 12‐story steel building is part of the CESMD, and the station number is 24546 . The steel building has a rectangular plan view 33.8 × 65.5 m (111 by 215 ft) with 15 acceleration sensors installed on five levels as shown schematically in Figure in elevation view for the NS loading direction.…”

Section: Evaluation Of the Proposed Methodsmentioning

confidence: 99%

Estimation of base motion in instrumented steel buildings using output‐only system identification

Lignos

Miranda

2013

Earthq Engng Struct Dyn

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SUMMARY A procedure to estimate the seismic motion at the base of a building from measured acceleration response at two or more floors is presented. The proposed method is comprised of two steps. In the first step, the dynamic characteristics of the building are inferred by using an output‐only system identification procedure. In the second step, the motion of the base of the building is estimated by using the transfer function of a simplified building model consisting of a shear and flexural continuous beam together with dynamic properties obtained in the first step. The proposed method is validated first with an analytical model subjected to the 1940 El Centro ground motion and then with an instrumented building in California that experienced the 1994 Northridge earthquake, and the ground motions at the base of the building are available. It is shown that the proposed method is capable of providing very good estimates of the motion at the base. The use of the proposed method is finally illustrated on an instrumented building, where the sensor at the base of the building did not function during the 1994 Northridge earthquake. Copyright © 2013 John Wiley & Sons, Ltd.

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“…A lack of published impact test data from analog instruments of the type which recorded most study data led the authors to conduct several experiments (see [55] for details). These experiments included dropping several small, common objects (pencil, roll of electrical tape, ream of copy paper, and round metal trash can) from a prescribed height at certain measured distances away from or directly on top of analog and digital accelerographs mounted on the floor (the digital results are not discussed here because there are no digital building response records to compare with).…”

Section: Procedures For Identification Of Likely Transient Causementioning

confidence: 99%

“…A high-pass filter with a corner frequency of 25 Hz and cut frequency of 25 Hz was used. A 2-level multi-resolution analysis using Daubechies wavelets was performed using Wavelab802 software [57]; more details on the analysis procedures used can be found elsewhere [55]. High-pass filtering and wavelet analysis help show that transient signals could be present at around 4.8, 10.5 and 10.8 s. If one were to start with the uncorrected data (as would typically happen), high pass filtering and wavelet analyses help to identify locations to look in the analog record.…”

Section: Los Angeles-office Building #3mentioning

confidence: 99%