Seismic Hazard Analysis and Probabilistic Ground Motions in the Upper Mississippi Embayment

Author(s):  
J. Alfredo Fernandez ◽  
Glenn J. Rix
2019 ◽  
Vol 35 (2) ◽  
pp. 759-786 ◽  
Author(s):  
Karim Tarbali ◽  
Brendon A. Bradley ◽  
Jack W. Baker

This paper focuses on the selection of ground motions for seismic response analysis in the near-fault region, where directivity effects are significant. An approach is presented to consider forward directivity velocity pulse effects in seismic hazard analysis without separate hazard calculations for ‘pulse-like’ and ‘non-pulse-like’ ground motions, resulting in a single target hazard (at the site of interest) for ground motion selection. The ability of ground motion selection methods to appropriately select records that exhibit pulse-like ground motions in the near-fault region is then examined. Applications for scenario and probabilistic seismic hazard analysis cases are examined through the computation of conditional seismic demand distributions and the seismic demand hazard. It is shown that ground motion selection based on an appropriate set of intensity measures (IMs) will lead to ground motion ensembles with an appropriate representation of the directivity-included target hazard in terms of IMs, which are themselves affected by directivity pulse effects. This alleviates the need to specify the proportion of pulse-like motions and their pulse periods a priori as strict criteria for ground motion selection.


2007 ◽  
Vol 23 (4) ◽  
pp. 867-891 ◽  
Author(s):  
Polsak Tothong ◽  
C. Allin Cornell ◽  
J. W. Baker

Probabilistic seismic hazard analysis (PSHA) is widely used to estimate the ground motion intensity that should be considered when assessing a structure's performance. Disaggregation of PSHA is often used to identify representative ground motions in terms of magnitude and distance for structural analysis. Forward directivity–induced velocity pulses, which may occur in near-fault (or near-source) motions, are known to cause relatively severe elastic and inelastic response in structures of certain periods. Here, the principles of PSHA are extended to incorporate the possible occurrence of a velocity pulse in a near-fault ground motion. For each magnitude and site-source geometry, the probability of occurrence of a pulse is considered along with the probability distribution of the pulse period given that a pulse does occur. A near-source “narrowband” attenuation law modification to predict ground motion spectral acceleration ( Sa) amplitude that takes advantage of this additional pulse period information is utilized. Further, disaggregation results provide the probability that a given level of ground motion intensity is caused by a pulse-like ground motion, as well as the conditional probability distribution of the pulse period associated with that ground motion. These extensions improve the accuracy of PSHA for sites located near faults, as well as provide a rational basis for selecting appropriate near-fault ground motions to be used in the dynamic analyses of a structure.


KURVATEK ◽  
2017 ◽  
Vol 1 (2) ◽  
pp. 41-47
Author(s):  
Marinda noor Eva

Penelitian mengenai daerah rawan gempa bumi ini menggunakan Metode Probabilistic Seismic Hazard Analysis (PSHA) di Provinsi Sulawesi Barat, dengan tujuan untuk memetakan tingkat kerawanan bahaya gempa bumi di Kabupaten Mamasa. Penelitian ini menggunakan data kejadian gempa bumi di Pulau Sulawesi dan sekitarnya dari tahun 1900 – 2015. Hasil pengolahan PSHA menggunakan Software Ez-Frisk 7.52 yang menghasilkan nilai hazard di batuan dasar pada kondisi PGA (T = 0,0 sekon), dengan periode ulang 500 tahun dan 2500 tahun berkisar antara (149,54 – 439,45) gal dan (287,18 – 762,81) gal. Nilai hazard di batuan dasar dengan kondisi spektra T = 0,2 sekon untuk periode ulang 500 tahun dan 2500 tahun adalah (307,04 – 1010,90) gal dan (569,48 – 1849,78) gal. Nilai hazard di batuan dasar dengan kondisi spektra T = 1,0 sekon untuk periode ulang 500 tahun dan 2500 tahun diperoleh nilai (118,01 – 265,75) gal dan (223,74 – 510,92) gal. Berdasarkan analisis PSHA, nilai PGA di Provinsi Sulawesi Barat dominan dipengaruhi oleh sumber gempa sesar.


Author(s):  
V.A. Mironov ◽  
S.A. Peretokin ◽  
K.V. Simonov

The article is a continuation of the software research to perform probabilistic seismic hazard analysis (PSHA) as one of the main stages in engineering seismic surveys. The article provides an overview of modern software for PSHA based on the Monte Carlo method, describes in detail the work of foreign programs OpenQuake Engine and EqHaz. A test calculation of seismic hazard was carried out to compare the functionality of domestic and foreign software.


Sign in / Sign up

Export Citation Format

Share Document