First Meeting of JRCP, Harbin, China, 2011

Som Issues
sues in Seismic
S i mcSomeHza d Assessment
ss ssment foror thetHazard
Nxt GenerationG nera ion Mapp
Next
Xiaxin TaoDoctor & Professor
School of Civil Engineering, Harbin Institute of Technology, China
Institute of Engineering Mechanics, CEA

20Novemberr 25
5 -30
NNovembv b250, 201011

First Meeting of JRCP, Harbin, China, 2011

Introduction
Seismic zonation plays a role of governmental policy forearthquake fortification, as a national standard in China.
� Seismic zonation in the world initiated at the end of 19
century in Russia.
� The related study started in 1920's after the Haiyuan
earthquake, and the first regional seismic zoning map in
China was published in 1923 and the first national mapin 1957.
� Some researchers mainly worked on statistics ofhistorical data （河角廣, 1951; Lomniz, 1967; Milne &Davenport, 1969）, while some others emphasized thetectonic cause of earthquake （Gubin,1978）.
�First Meeting of JRCP, Harbin, China, 2011

Introduction
Long term earthquake prediction from acomprehensive understanding of quake occurence
mainly on seismoligical and tectonic considerationhas
been a basis of the zoning.
� Engineering seismic hazard assessment (Cornel,1968; Mcguire, 1973), so called PSHA, is now widelyadopted in zoning maps in the world at national,regional and city level.
�First Meeting of JRCP, Harbin, China, 2011

1. Fundamentals
The fundamentals of strong earthquake occurrence
from regional seismicity and tectonic condition （Lee,1957) may be restated from what have been learned
from the recent large quakes.
� Strong earthquake may occur at a place where adestructive shock occurred with the similar magnitude-in what space-time area?
� Strong earthquake may occur at a place where thetectonic condition is similar with another place where adestructive shock occurred--how to characterize thetectonical condition and to define the similarity?
�First Meeting of JRCP, Harbin, China, 2011

Immunity--It takes time to accumulate enoughenergy in the crust for the next strong earthquake.
� Migration--Develo
whole rupture pro
� Filling--Linking th�First Meeting of JRCP, Harbin, China, 2011

�Case ofat Longmthan thaoccurredre

First Meeting of JRCP, Harbin, China, 2011

�The seismicity fluctuation must be taken into
account in seismicity parameter estimation.

�M-T plot of the South-eastern seismic zone

First Meeting of JRCP, Harbin, China, 2011

2. What data to be adopted
Available and necessary� Seismicity data, destructive and small event� Tectonic data, active fault and basin, blocks
� Geodetic data, such as GPS� Geophysical data, for the crust structure and deep
structure� Geodynamic understanding�First Meeting of JRCP, Harbin, China, 2011

3. How to process the data
� ?
� ?
� ?

First Meeting of JRCP, Harbin, China, 2011

How to pr�For example,
the past 200
occurred in 1
1897(M7.4) ，occurrence pated inhey.4) ，then.

First Meeting of JRCP, Harbin, China, 2011

How to process the data

Two rank potential source area delineation
The first rank PSA, seismic province or zone, for isquite large for enough data to statistics.
� The second rank PSA evaluated with its own upperbound magnitude, to be assigned with seismicity
parameters by a set of weighting factors.
�∑ W = 1.0iji�The values of factors are evluated from acomprehensive summary

Wij = ∑ fijkk�

can all factor values be summated together?

First Meeting of JRCP, Harbin, China, 2011

3. Ground motion attenuation relationships
Statistical results of Japan.
� Modification of the result of another region by
the intensity attenuation relationshipcomparison, in China.
� Based on seismological achievements forregion without enough strong ground motion
records.
� Dr. Tao is going to...
�First Meeting of JRCP, Harbin, China, 2011

4. The methematical formulation ofmodern PSHA is correct?

Truncate the distribution at what area?

First Meeting of JRCP, Harbin, China, 2011

5. A new idea
To combine the probabilistic seismic hazard
assessment and the scenario (deterministic) approachfor the map,� T��

First Meeting of JRCP, Harbin, China, 2011

Peak ground acceleration zoning map in a basin andits vicinity for case study is presented with thedifferent response spectra in two soil condition zones
further.
� Is it possible to take into account the local site
condition into account in a national map?
� Site condition is usually taken in microzonation next,
not in national map or regional map, in China.
� In some cases, the map is prepared by different
ground motion attenuation relations for plain andmountain regions respectively. Thus, is the site effectdoubled ?
�First Meeting of JRCP, Harbin, China, 2011

Conclusion
Five issues in seismic hazard assessment aremetioned in this presentation.
� Some of them are considered well, and I havedefinite answers, while more are recognized without
clear solutions.
� Please add anymore else on this meeting and in
this project.
� Let us work together resolve them, al least some ofthem, even not all.
�First Meeting of JRCP, Harbin, China, 2011

Thank you!
� Taoxiaxin@yahoo.com.cn