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D2-014
10:50
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11:05
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EMPIRICAL RELATION OF CUMULATIVE ABSOLUTE VELOCITY FOR WESTERN HIMALAYA
Evolutionary intensity measures can be considered as one of most efficient ground motion predictor in attenuation relation and seismic hazard assessment of region as compared to the peak transient measures. Peak transient measures viz., peak ground acceleration, peak ground velocity and response spectra defined at different natural period, only describe the maximum amplitude of ground motion records. Besides from peak amplitude, duration of records is an important characteristic for demarcating the boundary of destructive and non-destructive impact of earthquake on building and soil liquefaction. To remedy this issue Cumulative Absolute Velocity (CAV) can be used as an alternative of peak time domain parameters. Cumulative Absolute Velocity (CAV) is one of the best examples of evolutionary intensity measures as it amalgamates all characteristics of ground motion such as amplitude, duration and frequency content. Historical archives on the Cumulative Absolute Velocity asserted that it well correlates with onset structural damage of nuclear power plant and soil liquefaction. However, in literature the ground motion prediction equation based on CAV is very few in number as compared to peak transient measures. By considering the importance of this intensity parameter, the present study developed the empirical relation of geometric mean of horizontal component of the Cumulative Absolute Velocity for Western Himalaya Region as a function of earthquake magnitude, hypocentral distance and site-condition based on the Vs30. The Mixed effect regression technique has been employed to get the unbiased regression coefficients of the proposed model. The results obtained in the present study show that the model predict the higher value of CAV for soft soils (with a lower Vs30) as compared to rock (with a higher value of Vs30). The well defined mean trend and the lean dispersion of the observed Cumulative Absolute Velocity values in western Himalaya region, makes it useful for other regions where it can be easily projected. The use of such relationship will make the hazard and risk exercises more closure to realistic results and predictions.
Mukat Lal Sharma, Neha Kumari
cumulative absolute velocity, Ground Motion Prediction Equation, Western Himalaya
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D2-012
11:05
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11:20
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VERTICAL GROUND MOTION PREDICTION EQUATION FOR VERTICAL TO HORIZONTAL (V/H) RATIOS OF GROUND MOTION IN TAIWAN
We develop a new empirical ground-motion prediction equation (GMPE) to estimate the vertical ground motion component for engineer application in Taiwan. The development of the model used a data set complied mainly crustal earthquakes occurring within the Taiwan island, and partly worldwide earthquakes with large magnitudes filling the gap where the Taiwan earthquakes are not available. The model undertakes the advantage of the vertical Chiou and Youngs (2013) functional form with considering the earthquake magnitude (Mw), source to site distance (Rrup), style of faulting (Sof), and the shear – wave velocity of soil deposits in the upper 30 m of the site (Vs30) for the peak ground acceleration (PGA) and spectral accelerations (PSA) at periods of 0.01 to 3s. The independent – rotation – angles, RotD50, pseudo spectral acceleration values are used to compute the median prediction, total standard deviation and site – corrected standard deviation. The proposed model is applicable to design structure in Taiwan island for distances in the range of 0-300 km and magnitudes within 4.0 - 8.0. The applicable range for Vs30 is of 150 – 1500 m/s. The estimate vertical-to-horizontal spectral ratio from a pairs of vertical and horizontal GMPE has strong dependence on the period of response spectra, Vs30 and source to site distance, but weak dependence of magnitude. The dependence of V/H ratios on magnitude stronger in the short period. The model shows the dominant period at which the peak of V/H ratio attains its maximum is in the period range of 0.05 to 0.075s, and the amplitude of the peak is dependent of M, Sof and Ztor. For short periods, the V/H ratio decreases with increasing of Vs30, but increases with Vs30 at long periods. The V/H ratio model is also compared with other available models for validation.
VAN-BANG PHUNG, Chin-Hsiung Loh, Bor-Shouh Huang, Shu-Hsien Chao, Brian S.J Chiou
Earthquake Engineering, Earthquake Engineering, Ground Motion Prediction Equation, Vertical Design Spectrum, Vertical to Horizontal Spectral Ratio
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D2-013
11:20
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11:35
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SITE-DEPENDENT UNIFORM HAZARD RESPONSE SPECTRA FOR A MAJOR RESERVOIR PROJECT IN TAIWAN
A new method to set up site-dependent uniform hazard response spectra is adopted for a major reservoir. We supported the new ideal to solve the overestimated problem of the ground-motion values for the hazard curve in probabilistic seismic hazard analysis. Strong ground-motion data are obtained from the Taiwan Strong-motion Instrumentation Program (TSMIP). These data are used to establish peak ground acceleration (PGA) and response spectral acceleration (SA) ground?motion prediction equations. We used the strong-motion data recorded with the moment magnitude greater than 3.5, the distance smaller than 300 km, and from the stations within 70 km of the Mudan reservoir and geological conditions is similar with reservoir to build the “site-dependent ground-motion prediction model” in Taiwan. The obtained results show that the site-dependent ground?motion prediction equations give significantly lower variability as compared to the local set of global attenuation forms (Lin et al., 2011ab) from Taiwan data. This indicates that developing the site-dependent ground?motion prediction equations of an important infrastructure is necessary; it does not only improve the over conservatized problem but also obtain the more accurate prediction of ground motion values.
Jia-Cian Gao, Chyi-Tyi Lee
Earthquake Engineering, Ground Motion Prediction Equation, Probabilistic Seismic Hazard Analysis, Uniform Hazard Response Spectra
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D0-012
11:35
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11:50
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RAPID SITE EFFECT EVALUATION FOR RECENT DISASTER EARTHQUAKES IN TAIWAN FROM DENSE MICROTREMOR H/V MEASUREMENTS
Dense microtremor surveys were measured during 2001 to 2006 in whole Taiwan with interval around 5 km except mountain area and 1 km in metropolis region (Huang, 2009). Site response information could easily obtain including dominant frequency map, amplification map of dominant frequency and individual frequency band of each target sites from microtremor H/V technique (Wen and Huang 2012). These maps could be revisited after the disaster earthquake such as 2010 Jiaxian earthquake, 2016 Meinong earthquake and 2018 Hualian earthquake etc. Meanwhile, supplementary microtremor measurements were also introduced in this study for those damaged buildings and liquefaction regions to have a quick check about site effect related seismic disasters. For instance, most of the damage area was located in regions of dominant frequency around 1.2 Hz and which were corresponding to 10-story height damaged buildings during 2016 Meinong earthquake. Next, four high-rise buildings (around 10 floors) collapsed which located nearby the assumed fault trace for 2018 Hualien earthquake, the 1 Hz peak of microtremor H/V result were shown in surrounding regions. These results could help us to review disaster potential not only for these earthquakes but also for revisiting future building construction or even rebuild issues.
Che-Min Lin, Chun-Hsiang Kuo, Jyun-Yan Huang, Kuo-Liang Wen
microtremor H/V, Site Effect
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