SEISMIC HAZARD ASSESSMENT METHOD BASED ON THE STOCHASTIC MODELS OF SEISMICITY
Authors: Burtiev RASHID
The most informative measure of the seismic hazard
and the methodology of it assessment is developed. It means that in a location
of the Earth’s surface during the interval t, ground shaking will occur
n times and nk of them - with intensity of Ik. Such
approach may be useful for earthquake resistant construction strategy, because
each strong earthquake can affect the buildings’ resistance capacity. To
identify the area of earthquakes belonging to the concrete seismogenic zone the
cluster analysis is used. The Markov model of sequence
all seismic events from all seismogenic zones is elaborated, which allows to
forecast the interval values of latitudes, longitudes, depth of the hypocenters
and magnitudes of earthquakes. The coefficients of intensity attenuation equation
for Moldova, elaborated on the base of macroseismic data set of the
intermediate Vrancea earthquakes is defined. Macroseismic
field of Vrancea intermediate earthquakes extended from the southwest on the
northeast. A configuration, having the shape of an ellipse which major axis is
turned on angle γ0=510
concerning the positive direction of abscissa axis. The coefficients
of the attenuation relationships between seismic intensity I and earthquake's characteristics:
magnitude MW, epicentral
distance ρ, depth h in the Vrancea zone are represented by
empirical azimuth-dependent attenuation equation: I=aMW-blog(ρ2+h2)0.5+c.
The values were determined as follows: a=1.6;
c=7.2, the biggest axis of the ellipse being bmax=5.6 and the smallest bmin=4.9. Probabilistic seismic hazard analysis has been
performed and the map of seismic hazard of Moldova and adjacent territory is elaborated.
For performance demonstration
of the proposed method the different characteristics of seismic
hazard in Chisinau – capital of Moldova is calculated. The
probability values of occurrence at least one ground shaking with degree 4,..,8
of MSK-1964 intensities in the 50 years’ time period obtained using the
author's formula coincides with values obtained using the EUROCOD - 8 standards
for the same time period.
| Citation: | Burtiev RASHID (2017). SEISMIC HAZARD ASSESSMENT METHOD BASED ON THE STOCHASTIC MODELS OF SEISMICITY. Bulletin of IISEE, 51, 22-38, 2017. |