scholarly journals Strong-Motion Characteristics and Visual Damage Assessment Around Seismic Stations in Kathmandu after the 2015 Gorkha, Nepal, Earthquake

2017 ◽  
Vol 33 (1_suppl) ◽  
pp. 219-242 ◽  
Author(s):  
Subeg Bijukchhen ◽  
Nobuo Takai ◽  
Michiko Shigefuji ◽  
Masayoshi Ichiyanagi ◽  
Tsutomu Sasatani
Keyword(s):  
Damage Assessment ◽  
Strong Motion ◽  
Response Spectra ◽  
Period Range ◽  
Seismic Stations ◽  
Nepal Earthquake ◽  
Visual Damage ◽  
S Period ◽  
Motion Characteristics ◽  
2015 Gorkha Nepal Earthquake

A rapid visual damage assessment of buildings around four strong-motion seismic stations in Kathmandu Valley was carried out after the damaging Gorkha, Nepal earthquake (Mw7.8) of 25 April 2015. The waveforms of the main shock recorded at these stations were compared with the damage to buildings around the stations. The damage was found to be related to strong-motion characteristics of the earthquake. A dominance of long-period oscillation could be observed in the records. The damage to low-rise buildings in the valley was less than anticipated from an earthquake of this magnitude given that the majority of buildings were built without proper engineering consideration. The acceleration response spectra of one of the sedimentary sites show high response in the 1–2 s period range, and nearly 10% of the buildings, which were all low-rise, suffered damage around this site.

scholarly journals Case Study of a Heavily Damaged Building during the 2016 MW 7.8 Ecuador Earthquake: Directionality Effects in Seismic Actions and Damage Assessment

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 74
Author(s):  
Luis A. Pinzón ◽  
Luis G. Pujades ◽  
Irving Medranda ◽  
Rodrigo E. Alva
Keyword(s):  
Damage Assessment ◽  
Strong Motion ◽  
Response Spectra ◽  
Seismic Action ◽  
Damage State ◽  
Ground Acceleration ◽  
Intensity Measures ◽  
Capacity Curves ◽  
Building Orientation

In this work, the directionality effects during the MW 7.8 earthquake, which occurred in Muisne (Ecuador) on 16 April 2016, were analyzed under two perspectives. The first one deals with the influence of these effects on seismic intensity measures (IMs), while the second refers to the assessment of the expected damage of a specific building located in Manta city, Ecuador, as a function of its azimuthal orientation. The records of strong motion in 21 accelerometric stations were used to analyze directionality in seismic actions. At the closest station to the epicenter (RRup = 20 km), the peak ground acceleration was 1380 cm/s2 (EW component of the APED station). A detailed study of the response spectra ratifies the importance of directionality and confirms the need to consider these effects in seismic hazard studies. Differences between IMs values that consider the directionality and those obtained from the as-recorded accelerograms are significant and they agree with studies carried out in other regions. Concerning the variation of the expected damage with respect to the building orientation, a reinforced concrete building, which was seriously affected by the earthquake, was taken as a case study. For this analysis, the accelerograms recorded at a nearby station and detailed structural documentation were used. The ETABS software was used for the structural analysis. Modal and pushover analyses were performed, obtaining capacity curves and capacity spectra in the two main axes of the building. Two advanced methods for damage assessment were used to obtain fragility and mean damage state curves. The performance points were obtained through the linear equivalent approximation. This allows estimation and analysis of the expected mean damage state and the probability of complete damage as functions of the building orientation. Results show that the actual probability of complete damage is close to 60%. This fact is mainly due to the greater severity of the seismic action in one of the two main axes of the building. The results are in accordance with the damage produced by the earthquake in the building and confirm the need to consider the directionality effects in damage and seismic risk assessments.

scholarly journals Response of instrumented buildings under the 2016 Kaikoura earthquake

2017 ◽  
Vol 50 (2) ◽  
pp. 237-252 ◽  
Author(s):  
Reagan Chandramohan ◽  
Quincy Ma ◽  
Liam M. Wotherspoon ◽  
Brendon A. Bradley ◽  
Mostafa Nayyerloo ◽  
...  
Keyword(s):  
Structural Response ◽  
Strong Motion ◽  
Period Range ◽  
Motion Data ◽  
Response Data ◽  
Vibrational Characteristics ◽  
Modelling Techniques ◽  
S Period ◽  
Upper South ◽  
Kaikoura Earthquake

Six buildings in the Wellington region and the upper South Island, instrumented as part of the GeoNet Building Instrumentation Programme, recorded strong motion data during the 2016 Kaikoura earthquake. The response of two of these buildings: the Bank of New Zealand (BNZ) Harbour Quays, and Ministry of Business, Innovation, and Employment (MBIE) buildings, are examined in detail. Their acceleration and displacement response was reconstructed from the recorded data, and their vibrational characteristics were examined by computing their frequency response functions. The location of the BNZ building in the CentrePort region on the Wellington waterfront, which experienced significant ground motion amplification in the 1–2 s period range due to site effects, resulted in the imposition of especially large demands on the building. The computed response of the two buildings are compared to the intensity of ground motions they experienced and the structural and nonstructural damage they suffered, in an effort to motivate the use of structural response data in the validation of performance objectives of building codes, structural modelling techniques, and fragility functions. Finally, the nature of challenges typically encountered in the interpretation of structural response data are highlighted.

Construction of strong motion response spectra from magnitude and distance data

1964 ◽  
Vol 54 (5A) ◽  
pp. 1257-1269
Author(s):  
John H. Wiggins
Keyword(s):  
Strong Motion ◽  
Response Spectra ◽  
Earthquake Magnitude ◽  
Empirical Equations ◽  
Maximum Acceleration ◽  
Period Range ◽  
Motion Response ◽  
Characteristic Period ◽  
Earthquake Records ◽  
Distance Data

Abstract Empirical equations are derived which relate maximum acceleration, velocity, and displacement computed from strong motion earthquake records to magnitude and distance from source to site. Over fifty earthquakes recorded at three California sites were used in the study. The equations show that earthquake magnitude governs not only the character of response spectra but also the characteristic period content of the earthquake. As an added feature, the reported Modified Mercalli intensities are shown to correlate best with computed response spectra which include only the low period range.

Analysis of Strong Motion Records from Uttarkashi Earthquake for Assessment of Code Provisions for Different Seismic Zones

1993 ◽  
Vol 9 (4) ◽  
pp. 739-754 ◽  
Author(s):  
Sudhir K. Jain ◽  
Satrajit Das
Keyword(s):  
Seismic Design ◽  
Strong Motion ◽  
Response Spectra ◽  
Average Response ◽  
Period Range ◽  
Strong Motion Records ◽  
Seismic Zones ◽  
Time Histories ◽  
Present Design ◽  
Codal Provisions

Strong motion records have been obtained at 13 stations during the Uttarkashi earthquake of October 20, 1991 (magnitude 6.6). A study has been conducted on these time histories to assess the codal provisions in India. Emphasis of the study is on evaluating relative consistency of design provisions for different seismic zones in India. The average response spectra from this earthquake show concentration of significantly more energy in low period range and less energy in high period range. The magnitude of seismic design force for zones I, II, and III is consistent while it is too low for zone IV; no records were obtained in area with shaking intensity corresponding to zone V. It is seen that for buildings in zones I, II, and III, the present design provisions may be lowered either by relaxing the requirement of special ductile detailing, or by reducing the design force. On the other hand, design provisions for zone IV need to be revised upwards.

Strong motion accelerograph records from the 1993 Napierville earthquake

1995 ◽  
Vol 22 (1) ◽  
pp. 190-196
Author(s):  
René Tinawi ◽  
André Filiatrault ◽  
Pierre Léger
Keyword(s):  
Ground Motion ◽  
Energy Content ◽  
Strong Motion ◽  
Response Spectra ◽  
High Energy ◽  
Period Range ◽  
Attenuation Relationships ◽  
Acceleration Time Histories ◽  
Short Period ◽  
Time Histories

An earthquake of magnitude ML = 4.3 occurred near Napierville, Quebec, on November 16, 1993. An accelerograph at the liquefaction, storage, and regasification plant of Gaz Metropolitain in Montreal, about 55 km from the epicentre, recorded the ground motion. Although the maximum accelerations and velocities from this event are small, the acceleration time histories do confirm the high energy content in the very short period range. The recorded ground motion and corresponding absolute acceleration response spectra are presented and various attenuation relationships, proposed for eastern North America, are utilized to compare the measured and predicted ground motion parameters. Key words: Napierville earthquake, attenuation relationships, acceleration spectra, strong motion records.

scholarly journals Aftershock activity of the 2015 Gorkha, Nepal, earthquake determined using the Kathmandu strong motion seismographic array

2016 ◽  
Vol 68 (1) ◽  
Author(s):  
Masayoshi Ichiyanagi ◽  
Nobuo Takai ◽  
Michiko Shigefuji ◽  
Subeg Bijukchhen ◽  
Tsutomu Sasatani ◽  
...  
Keyword(s):  
Strong Motion ◽  
Aftershock Activity ◽  
Nepal Earthquake ◽  
2015 Gorkha Nepal Earthquake

Displacement Spectra for Long Periods

2004 ◽  
Vol 20 (2) ◽  
pp. 347-376 ◽  
Author(s):  
Ezio Faccioli ◽  
Roberto Paolucci ◽  
Julien Rey
Keyword(s):  
Strong Motion ◽  
Seismic Source ◽  
Response Spectra ◽  
Analytical Models ◽  
Elastic Displacement ◽  
Period Range ◽  
Motion Data ◽  
Displacement Spectra ◽  
Long Period ◽  
Displacement Response Spectra

Using selected sets of high-quality digital strong motion data from different regions (Taiwan, Japan, Italy, and Greece), the salient features of displacement response spectra in the long-period range are illustrated (up to 10 s period) as a function of magnitude, source distance, and site conditions. By means of simple analytical models of displacement waveforms, we have derived analytical expressions for the displacement spectra that provide satisfactory fits to the observations. These expressions also demonstrate that the moment magnitude and distance control the shape of the spectra consistent with the commonly accepted models of the seismic source. Furthermore, we derived from simple physical considerations an analytical expression of the variation of peak ground displacement with magnitude and distance that reasonably fits the observations. The findings of this study are believed to be particularly useful in the formulation of design elastic displacement spectra for seismic codes, and in zoning studies of seismic hazard for long-period structures.

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