scholarly journals The estimated PGA map of the Mw6.4 2006 Yogyakarta Indonesia earthquake, constructed from the Modified Mercalli intensity IMM

Author(s):  
Widodo Pawirodikromo

Many moderate and strong earthquakes have occurred in Indonesia. However, since ground motion records are unavailable, a concise earthquake peak ground acceleration (PGA) map has never before been constructed. Several efforts have been made to construct PGA maps after the Mw6.4 2006 Yogyakarta earthquake, i.e. earthquake PGA maps by researchers [1–4]. However, due to their use of completely different earthquake sources, methods of analysis and by using exclusion criteria of ground motion prediction equations (GMPE), the maps differed greatly and did not match the actual structural damage found in the field. Estimation of a 2006 Yogyakarta earthquake PGA map became possible after field surveying of the Imm conducted by Wijaya [5]. The estimated PGA map was constructed based on the isoseimic lines, intensity prediction equation (IPE) by Wijaya [5] and peak ground acceleration at YOGI and BJI station control points, as published by Elnashai et al [6]. A set of most recent GMPEs were chosen, as they closely predicted the PGA at two control points. An Extrapolation Method was developed in which the PGA between YOGI and BJI stations would be extrapolated to all data points in the field to yield the 2006 Yogyakarta seismic PGA map. Result of the investigation indicated that the pattern of the new PGA map does not form a circle with radius R, but occurs longitudinally following the direction of the Opak River fault trace and closely follows the pattern of Imm map and damage to buildings in the field. It was found that the maximum upperbound PGA reached ±0.50-0.51g and it did not occur at the epicenter area but instead took place in relatively deep soil deposit approximately ±2 km west of the Opak River fault.

2020 ◽  
Vol 36 (2_suppl) ◽  
pp. 154-174
Author(s):  
Sergio Alcocer ◽  
Anahid Behrouzi ◽  
Sergio Brena ◽  
Kenneth J Elwood ◽  
Ayhan Irfanoglu ◽  
...  

Over 2000 buildings were surveyed by members of the Colegio de Ingenieros (CICM) and Sociedad Mexicana de Ingenieria Estructural (SMIE) in Mexico City following the Puebla-Morelos Earthquake of 2017. This inventory of surveyed buildings included nearly 40 collapses and over 600 buildings deemed to have structural damage. Correlation of damage with peak ground acceleration (PGA), peak ground velocity (PGV), predominant spectral period, building location, and building properties including height, estimated stiffness, and presence of walls or retrofits was investigated for the surveyed buildings. The evidence available suggests that (1) ground motion intensity (PGV) drove the occurrence of damage and (2) buildings with more infill and stiff retrofit systems did better than other buildings.


Looking into the present scenario worldwide, it is obvious that there is rapid increase in construction activities hence, the vulnerability to calamities of areas leading to large loss potentials. So the researches all over the globe are basically focused over disaster management, to safeguard the life and properties. The district headquarters Dantewara, Jagdalpur and Kanker are located in the south of Chhattisgarh state (India), where high concentration of the tribal population and rapid infrastructure development is observed. In order to trim down vulnerability, precise microzonation studies are required to be a constituent of the master plan, for construction activities, of earthquake resistant structures in the south of Chhattisgarh region. In the present research, the Deterministic Seismic Hazard Analysis (DSHA) for district headquarters of south Chhattisgarh has been carried out. In order to estimate the seismic parameters, past earthquake data of district headquarters of south Chhattisgarh, with radius of 300kM around them has been analyzed. Thirteen, Twelve and Eighteen tectonic features have been identified as potential seismogenic source, from the seismotectonic atlas of India for Dantewara, Jagdalpur and Kanker respectively. The maximum magnitude has been assigned to each seismogenic source. To evaluate the hazard in the study region, Ground Motion Prediction Equation (GMPE) developed by Cornell (1976) and Raghukanth and Iyengar (2004) has been used. The Peak Ground Acceleration (PGA) values are estimated for district headquarters of Dantewara, Jagdalpur & Kanker around its adjoining areas. Maximum PGA value for return period of100 years at bed rock level is 0.05063g and 0.06378g for Dantewara region using Ground Motion Prediction Equation (GMPE) developed by Cornell (1976) and Raghukanth & Iyengar (2004). It has been reported from the study that the above values are found to be on the lower side as compared to the recommendation given by IS Code of practice (IS:1893 part I (2016).The outcome of present research can be directly implemented for design of earthquake resistant structures in south Chhattisgarh region. Thus the study accounts that south Chhattisgarh is safe from seismic risk.


An effective earthquake (Mw 7.9) struck Alaska on 3 November, 2002. This earthquake ruptured 340 km along Susitna Glacier, Denali and Totschunda faults in central Alaska. The peak ground acceleration (PGA) was recorded about 0.32 g at station PS10, which was located 3 km from the fault rupture. The PGA would have recorded a high value, if more instruments had been installed in the region. A numerical study has been conducted to find out the possible ground motion record that could occur at maximum horizontal slip during the Denali earthquake. The current study overcomes the limitation of number of elements to model the Denali fault. These numerical results are compared with observed ground motions. It is observed that the ground motions obtained through numerical analysis are in good agreement with observed ground motions. From numerical results, it is observed that the possible expected PGA is 0.62 g at maximum horizontal slip of Denali fault.


2015 ◽  
Vol 754-755 ◽  
pp. 897-901
Author(s):  
Saffuan Wan Ahmad ◽  
Azlan Adnan ◽  
Rozaimi Mohd Noor ◽  
Khairunisa Muthusamy ◽  
Sk Muiz Sk Razak ◽  
...  

An attenuation relationship for far field earthquakes considered by strike slip has been developed. The attenuation relationship function was develop using regression analysis. The database consisting of more than 130 peak ground accelerations from seven earthquake sources recorded by Seismology Station in Malaysia have been used to develop the relationship. This study aims to investigate the new relationship attenuation to gain exact peak ground acceleration at the location on site. Based on this study, the location is a structure located at Terengganu seaside.


2017 ◽  
Vol 33 (4) ◽  
pp. 1533-1554 ◽  
Author(s):  
Mehrdad Shokrabadi ◽  
Henry V. Burton

This paper investigates the effectiveness of various ground motion intensity measures (IMs) in estimating the structural response of two types of rocking systems: (a) a controlled rocking steel braced frame system with self-centering action and (b) a rocking spine system for reinforced concrete infill frames. The IMs are evaluated based on the dispersion in engineering demand parameter (EDP) predictions (efficiency) and the sensitivity of the conditional distributions of EDPs to the distributions of the magnitudes, distances and spectral shape parameter (ε) of ground motion records (sufficiency). The EDPs include maximum transient and residual story drifts and peak floor accelerations. The spectral acceleration averaged over a range of periods (Sa avg) is most effective for predicting transient and residual drift demands and peak ground acceleration (PGA) is generally the best predictor of peak floor accelerations. The proximity of the frequency range most affecting an EDP to that best reflected in an IM is found to be a good indicator of the performance of that IM.


Author(s):  
A. K. Ghosh ◽  
H. S. Kushwaha

The various uncertainties and randomness associated with the occurrence of earthquakes and the consequences of their effects on the NPP components and structures call for a probabilistic seismic risk assessment (PSRA). However, traditionally, the seismic design basis ground motion has been specified by normalised response spectral shapes and peak ground acceleration (PGA). The mean recurrence interval (MRI) used to be computed for PGA only. The present work develops uniform hazard response spectra i.e. spectra having the same MRI at all frequencies for Kakrapar Atomic Power Station site. Sensitivity of the results to the changes in various parameters has also been presented. These results determine the seismic hazard at the given site and the associated uncertainties. The paper also presents some results of the seismic fragility for an existing containment structure. The various parameters that could affect the seismic structural response include material strength of concrete, structural damping available within the structure and the normalized ground motion response spectral shape. Based on this limited case study the seismic fragility of the structure is developed. The results are presented as families of conditional probability curves plotted against the peak ground acceleration (PGA). The procedure adopted incorporates the various randomness and uncertainty associated with the parameters under consideration.


2017 ◽  
Vol 17 (4B) ◽  
pp. 82-95
Author(s):  
Nguyen Anh Duong ◽  
Pham Dinh Nguyen ◽  
Vu Minh Tuan ◽  
Bui Van Duan ◽  
Nguyen Thuy Linh

In this study, we have carried out the probabilistic seismic hazard analysis in Hanoi based on the latest seismotectonic data. The seismic hazard map shows peak ground acceleration values on rock corresponding to the 10% probability of exceedance in a 50-year time period (approximately return periods of 500 years). The calculated results reveal that the maximum ground acceleration can occur on rock in Hanoi is about 0.13 g corresponding to the shaking intensity level of VIII on the MSK-64 scale. The ground motion values calculated on rock vary according to the local site conditions. We have evaluated and corrected the local site effects on ground motion in Ha Dong district, Hanoi by using microtremor and borehole data. The Nakamura’s H/V spectral ratio method has been applied to establish a map of ground dominant periods in Ha Dong with a TS range of 0.6 - 1.2 seconds. The relatively high values of periods indicate that Ha Dong has soft soil and thick Quaternary sediments. The sediment thickness in Ha Dong is calculated to vary between 30 - 75 m based on ground dominant periods and shear wave velocity VS30 = 171 - 254 m/s. The results of local site effect on ground motion show that the 500-year return period peak ground acceleration in Ha Dong ranges from 0.13 g to 0.17 g. It is once again asserted that the seismic hazard in Hanoi is a matter of great concern, due not only to the relatively high ground acceleration, but also to the seismic characteristics of soil (low shear wave velocity, ground dominant period of approximately 1 second).


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