A Case Study of Accelerometric Records Analysis of May 21st, 2003, Boumerdes (Algeria) Earthquake

2013 ◽  
Vol 4 (2) ◽  
pp. 34-52 ◽  
Author(s):  
Abdelwahab Mourad Khellafi ◽  
Zamila Harichane ◽  
Hamid Afra ◽  
Amina Sadouki
Keyword(s):  
Earthquake Engineering ◽  
Epicentral Distance ◽  
Near Field ◽  
Response Spectra ◽  
Soil Conditions ◽  
Eurocode 8 ◽  
Earthquake Epicenter ◽  
Ground Acceleration ◽  
Design Spectra ◽  
The North

On May 21st, 2003, the north Algeria was stricken by a 6.8 magnitude earthquake which was felt over a distance of 250 km from the epicenter, which is localized in Mediterranean Sea at 10 km from the coast. During this event, several ground accelerations were recorded by the instrumentation network of the National Center of Applied Research in Earthquake Engineering (CGS). The records analysis revealed an important difference in peak ground acceleration (PGA) between two close stations (0.58g and 0.33g, respectively, in East-West direction) at about 20 km from the earthquake epicenter. Also, two other record stations, located in the Mitidja basin, at about 29 km and 86 km from the earthquake epicenter, respectively, showed a high level of acceleration: PGAs of 0.54g and 0.16g. So, the authors attempt in this paper to analyze these records through the characteristics of strong ground motions, the effects of different parameters such as damping ratios, soil conditions and epicentral distance on normalized response spectra. Also, the quantification of site effects during this earthquake is analyzed. Then, the authors compare the near-field mean response spectra obtained during this earthquake with the Algerian seismic design spectra (RPA99 – 2003 version) and with two other well-known design spectra: Eurocode 8 and UBC97 in order to contribute to the future revision of RPA99.

Seismic Hazard Assessment in the Southeastern United States

1995 ◽  
Vol 11 (1) ◽  
pp. 129-160 ◽  
Author(s):  
Paul C. Rizzo ◽  
N. R. Vaidya ◽  
E. Bazan ◽  
C. F. Heberling
Keyword(s):  
North American ◽  
Peak Ground Acceleration ◽  
Ground Motions ◽  
Near Field ◽  
Southeastern United States ◽  
Seismic Hazard Assessment ◽  
Response Spectra ◽  
Seismic Hazards ◽  
Far Field ◽  
Ground Acceleration

Comparisons of response spectra from near and far-field records to those estimated by attenuation functions commonly used in evaluating seismic hazards show that these functions provide reasonable results for near-field western North American sites. However, they estimate relatively small motions for far-field eastern North American sites, which is contrary to the empirical evidence of the 1886 Charleston and 1988 Saguenay Earthquakes. Using the 1988 Saguenay records scaled for magnitude, and several western North American records scaled to account for the slower attenuation in the east, we have developed deterministic median and 84th percentile, 5 percent damped response spectra to represent ground motions from a recurrence of the 1886 Charleston Earthquake at a distance between 85 to 120 km. The resulting 84th percentile spectrum has a shape similar to, but is less severe than, the USNRC Regulatory Guide 1.60 5 percent damped spectrum tied to a peak ground acceleration of 0.2g.

Generation of seismic excitations compatible with target spectrum: application to Eurocode 8

2020 ◽  
Vol 18 (1) ◽  
pp. 122-135
Author(s):  
Abdellah Boudina ◽  
Malek Hammoutene
Keyword(s):  
Epicentral Distance ◽  
Response Spectrum ◽  
Ground Motions ◽  
Environmental Parameters ◽  
Eurocode 8 ◽  
Ground Acceleration ◽  
Content Type ◽  
Strong Ground Motions ◽  
Acceleration Time Histories ◽  
Strong Ground

Purpose This paper aims to artificially generate seismic accelerograms compatible with the response spectrum imposed as a function of the given environmental parameters such as magnitude, epicentral distance and type of soil. This study is necessary for the non-linear dynamic analysis of structures in regions where real seismic records are not available. Design/methodology/approach First, a stochastic iterative method is used to estimate the spectral densities of acceleration power from the respective target response spectra. Thereafter, based on the superposition of seismic waves, a subsequent iterative procedure, which implicitly takes into account the non-stationary character of temporal intensity content of strong ground motions, is developed to synthesize, from these power spectral density, the corresponding acceleration time histories. The phase contents of the ground acceleration samples, thus obtained, are generated using a probability density function of phase derivatives with characteristic parameters estimated from seismological considerations. When based on seismic codes spectrum compatible criteria, this procedure can be used to generate strong ground motions for structural design. Findings The results found show that the forms of acceleration of the target and the simulated signals have similar characteristics in terms of strong motion durations, the peak ground acceleration values, corresponding time of occurrence and also, the corresponding cumulative energy functions follow practically the same pattern of variations. Originality/value The aim of this study is to generate seismic accelerograms compatible with regulatory spectra by the composition of the three acceleration duration segments based on environmental parameters (magnitude, epicentral distance and type of soil) and which subsequently serves to control the time envelope of the generated signals, and therefore the random generation of phase derivatives, which has not been previously treated.

Accelerograms of the 1978 Tabas, Iran, Earthquake

1986 ◽  
Vol 2 (3) ◽  
pp. 635-651 ◽  
Author(s):  
Mansour Niazi
Keyword(s):  
Main Shock ◽  
Epicentral Distance ◽  
Source Region ◽  
Response Spectra ◽  
Rupture Surface ◽  
Ground Acceleration ◽  
Complex Source ◽  
Vertical Ground ◽  
Elastic Design ◽  
Tabas Earthquake

Three triaxial sets of accelerograms recorded in the near source region (within 50 km epicentral distance) of the September 16, 1978, Tabas earthquake (Ms 7.4 -7.7) are of great engineering importance. The distances of the recording sites from the nearest approach of the rupture surface are approximately 3, 17, and 28 km for Tabas, Dayhook and Boshrooyeh stations, respectively. The measured horizontal peak ground accelerations of 0.94 and 0.88 g at Tabas are higher than previously estimated. The peak vertical ground acceleration recorded at this station is 0.74 g. The normalized response spectra at these three stations are consistent with the Newmark-Hall elastic design spectra, suggesting that the latter adequately represent the spectral amplification factors at frequencies above 1 Hz. The main shock accelerogram at Dayhook exhibits at least three distinct events as indication of a complex source behavior. The widened spacing of these events on the Dayhook records further confirms that the rupture front moved northwestward away from this station and towards Tabas. The measured S minus trigger times at Tabas, Dayhook and Boshrooyeh stations are in conflict with the teleseismically determined epicenter, requiring it to move approximately 30 km to the southwest to about 33° 17′N, 57° 09′ E.

Acceleration Response Spectra for M 7.4 Donggala Earthquake and Comparison with Design Spectra

2019 ◽  
Vol 1 (1) ◽  
pp. 20-26
Author(s):  
Bambang Sunardi ◽  
Sulastri ◽  
Dwikorita Karnawati ◽  
Urip Haryoko ◽  
Supriyanto Rohadi ◽  
...  
Keyword(s):  
Response Spectra ◽  
Acceleration Response ◽  
Ground Acceleration ◽  
Site Class ◽  
Design Spectra ◽  
Acceleration Response Spectra ◽  
Hard Soil ◽  
Hazard Level ◽  
Earthquake Area ◽  
Peak Value

A 7.4 magnitude earthquake have strucked Donggala on September 28th 2018, followed by tsunami and liquefaction which hit Palu, Central Sulawesi, a few minutes later. This event had resulted in damage to buildings, and caused more than 2,000 people were killed and injured. Indonesia already have a building code in form of SNI 1726:2002 which had been updated to SNI 1726:2012. This paper analyses the hazard level caused by the 2018 Donggala earthquake compared to the existing design spectra, as mentioned in SNI 1726:2002 and SNI 1726:2012. A simple analysis was carried out by comparing Donggala earthquake’s acceleration response spectra with the existing design spectra, at the MPSI accelerograph station. The site class at MPSI station is hard soil (SC). The seismic hazard in Palu and Donggala refers to SNI 1726:2002 is included in the earthquake area 4. The maximum earthquake response factor for earthquake area 4 is about 0.6 for hard soil type (SC). The MPSI station recorded peak ground acceleration of Donggala earthquake around 0.14 g. The acceleration response spectra recorded at the MPSI station showed a peak value of around 0.71 g for the N component. This value is actually still below the design spectra referring to SNI 1726:2012, which the peak value is 0.88 g for SC, but, it exceeded the design spectra of SNI 1726:2002.

The SMART I Accelerograph Array (1980-1987): A Review

1987 ◽  
Vol 3 (2) ◽  
pp. 263-287 ◽  
Author(s):  
N. A. Abrahamson ◽  
B. A. Bolt ◽  
R. B. Darragh ◽  
J. Penzien ◽  
Y. B. Tsai
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Ground Motions ◽  
Near Field ◽  
Strong Motion ◽  
Response Spectra ◽  
Transform Faults ◽  
Engineering Research ◽  
Motion Data ◽  
Time Histories

SMART 1 is the first large digital array of strong-motion seismographs specially designed for engineering and seismological studies of the generation and near-field properties of earthquakes. Since the array began operation in September 1980, it has recorded over 3000 accelerogram traces from 48 earthquakes ranging in local magnitude ( ML) from 3.6 to 7.0. Peak ground accelerations have been recorded up to 0.33g and 0.34g on the horizontal and vertical components, respectively. Epicentral distances have ranged from 3 km 200 km from the array center, and focal depths have ranged from shallow to 100 km. The recorded earthquakes had both reverse and strike-slip focal mechanisms associated with the subduction zone and transform faults. These high quality, digital, ground motions provide a varied resource for earthquake engineering research. Earthquake engineering studies of the SMART 1 ground motion data have led to advances in knowledge in several cases: for example, on frequency-dependent incoherency of free-surface ground motions over short distances, on response of linear systems to multiple support excitations, on attenuation of peak ground-motion parameters and response spectra, on site torsion and phasing effects, and on the identification of wave types. Accelerograms from individual strong-motion seismographs do not, in general, provide such information. This review describes the SMART 1 array and the recorded earthquakes with special engineering applications. Also, it tabulates the unfiltered peak array accelerations, displays some of the recorded ground motion time histories, and summarizes the main engineering research that has made use of SMART 1 data.

scholarly journals The ratio of response spectra from seismic-type free-field and building foundation vibrations: the influence of rockburst parameters and simple models of kinematic soil-structure interaction

2019 ◽  
Vol 18 (3) ◽  
pp. 907-924 ◽  
Author(s):  
Krystyna Kuzniar ◽  
Tadeusz Tatara
Keyword(s):  
Soil Structure ◽  
Epicentral Distance ◽  
Free Field ◽  
Response Spectra ◽  
Soil Structure Interaction ◽  
Ground Acceleration ◽  
Structure Interaction ◽  
Building Foundation ◽  
Mining Tremors ◽  
The Impact

Abstract Mining-related seismicity is a significant problem in regions with the exploitation in underground mines. Despite the fact that mining tremors result from human activity and are classified as so-called paraseismic shocks, as with earthquakes, they are random events. Moreover, these rockbursts could cause significant damage to surface structures, including buildings. This paper deals with the analysis of experimentally obtained results in terms of the differences between the mine-induced vibrations described by the response spectra from the free-field near a given building and the simultaneously recorded vibrations in the building foundations. The influences of epicentral distance, mining tremor energy and the value of peak ground acceleration on the curves of free-field—foundation response spectra ratio were studied. The impact of the type of building on the transmission of response spectra from the free-field vibrations to the building foundations was also analysed for three types of apartment buildings (low-rise, medium-rise, high-rise). The usefulness of the approximate models of the phenomenon of soil-structure interaction during earthquakes proposed in the literature is also estimated in this paper in specific instances of mining tremors. Furthermore, the study presents original, simple, empirical models for the evaluation of the differences in the response spectra originating from free-field and building foundation vibrations in the mining region.

scholarly journals Towards preparation of design spectra for Serbian national annex to Eurocode 8: Part II. Usage of the UHS approach instead of normalized spectral shapes scaled by a single PSHA parameter

2012 ◽  
Vol 10 (3) ◽  
pp. 259-274
Author(s):  
Borko Bulajic ◽  
Miodrag Manic ◽  
Djordje Ladjinovic
Keyword(s):  
Seismic Hazard ◽  
Peak Ground Acceleration ◽  
Eurocode 8 ◽  
Uniform Hazard Spectra ◽  
Ground Acceleration ◽  
Earthquake Parameters ◽  
Design Spectra ◽  
The Given

Eurocode 8 spectra are scaled by the peak ground acceleration values that are defined for the given site through a probabilistic seismic hazard analyses (PSHA). However, spectra that are created by combining the empirical shapes with the single PSHA-defined scaling factor will not represent the so-called Uniform Hazard Spectra (UHS). Moreover, the very shape (Type 1 or Type 2) of the Eurocode 8 elastic spectrum is selected with respect to the magnitude of the earthquakes ?that will contribute most to the seismic hazard defined for the purpose of probabilistic hazard assessment??. Such definition is somewhat obscure since these ?most contributing? earthquakes are, even at the same site and for the same probability i.e. for the same ?return period?, different (in a general case) for different vibration periods, while the whole Eurocode 8 spectrum is scaled by using only the PSHA estimate of the peak ground acceleration. In this Paper we present an illustrative example of the Uniform Hazard Spectra for the city of Belgrade and compare the obtained UHS spectra, as well as the scenario empirical spectra scaled for different earthquake parameters, to the corresponding Eurocode 8 spectra, further pointing out the intrinsic ambiguities in the current EC8 suggestions for creation of design spectra.

Recorded Ground Motion and Estimated Soil Amplification for the 11 May 2011 Lorca Earthquake

2015 ◽  
Vol 31 (4) ◽  
pp. 2301-2323 ◽  
Author(s):  
Myriam Belvaux ◽  
Albert Macau ◽  
Sara Figueras ◽  
Xavier Goula ◽  
Teresa Susagna
Keyword(s):  
Ground Motion ◽  
Site Response ◽  
Ground Motions ◽  
Near Field ◽  
Elastic Response ◽  
Eurocode 8 ◽  
Soil Amplification ◽  
Ground Acceleration ◽  
Geophysical Field ◽  
Elastic Response Spectra

On 11 May 2011 an earthquake of magnitude 5.2 ( M w) hit the Murcia region of Spain causing significant damage to buildings in the town of Lorca. Accelerograms were recorded by stations of the Instituto Geográfico Nacional, and high-amplitude ground motions were observed at the Lorca station, with a peak ground acceleration (PGA) of 0.37 g. The contribution of a near-field component of ground motion is shown in time histories and in elastic response spectra. Features of near-field ground motions such as directivity could have significantly enhanced the ground shaking caused by this event. Local amplification effects in Lorca were investigated by the H/V spectral ratio technique and an array method. Information obtained from the geophysical field survey allowed the definition of representative soil columns and site classifications according to Eurocode 8. Modeling of site response is conducted for an example location. The aftershocks recorded at different sites confirm the soil amplification at these locations.

scholarly journals Using 1 -D and 2-D modelling of ground motion for seismic zonation criteria: results for the city of Rome

1995 ◽  
Vol 38 (5-6) ◽  
Author(s):  
A. Rovelli ◽  
L. Malagnini ◽  
A. Caserta ◽  
F. Marra
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Response Spectra ◽  
Ground Acceleration ◽  
Seismic Zonation ◽  
Geological Information ◽  
Horizontal Ground Motion ◽  
Numerical Generation ◽  
Flux Response ◽  
The City

The geological information collected in the last years by the Istituto Nazionale di Geofisica for the city of Rome is used to construct 1- and 2-D models of the nearsurface structure. These models are the basis for the numerical generation of synthetic accelerograms which can simulate the horizontal ground motion (SH waves) produced in the different areas of the city by a large (M ? 7) potential earthquake 100 km away in Central Apennines. The proposed methodology yields earthquake engineering parameters (peak ground acceleration and velocity, Arias intensity, energy flux, response spectra) whose spatial variations are consistent with the damage distribution caused by the strongest earthquakes felt in Rome during its long history. Based on the macroseismic inforination and the results of the numerical simulations, general criteria for seismic zonation of the city of Rome are proposed.

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