Lehre

to be held on October 13-14, 2005

at Bauhaus-University Weimar,  International Congress Center "Harry Graf Kessler"

Organized by

Bauhaus-University Weimar, Faculty of Civil Engineering, Earthquake Damage Analysis Center (EDAC)

1   Short historic review

In 1996 the ESC General Assembly recommended the use of the European Macroseismic Scale EMS-98 in Europe. Moreover, the scale is applied in many regions outside of Europe. After six years of use, the testing version (EMS-92) could be revised on the basis of field studies and experiences from a series of damaging earthquakes (Kobe, Northridge, Aigion, Cariaco) where all the types of engineered buildings were affected.

In the introduction of the scale it is emphasized that “further macroseismic practice may enable a deeper insight into the complex matters of assigning intensity. Future applications on future needs might be the basis for further improvement of this new tool”.

After a Special Theme Sessions during the WCEE in Acapulco 1996 and the ESC in Tel Aviv 1998 the joint discussion and exchange of experience between engineers and seismologist with respect to the EMS should be deepened.

There were no further activities concerning the check of the European Macroseismic Scale 98, of its applications (correct or more or less misleading), no exchange of experiences, questions and problems from field surveys.

Meanwhile, the EMS-98 was translated into different languages (Spain, French, Russian) with the support of colleagues being familiar with macroseismic tasks.

2   Objectives

Nevertheless, the growth of experience from practical application may contribute to a clarification of statements within the scale, to identify existing problems (weak points) and to come up with proposals for its further use:  

• Response has to be given from editorial side concerning critical statements and heavy attacks against the use of EMS-98.
• Response has to be given from editorial side to the concentration on and overestimation of seismogeological phenomena.  
• Of particular importance is the experience in re-interpretation of historic earthquakes and the final intensity assignments. 
• During the last years, the vulnerability table of the EMS-98 and also the vulnerability functions (intended as model functions, only) do provide the basis for risk assessments and damage scenarios. Many applications of the EMS in this field are reported, world-wide.
   

From the engineering side the following topics wait for comments, discussion, and common positions:

As stated in the EMS, the use of damage surveys is regarded to be “the key for introducing new building types as well as for better correlating particular building types with the most likely or probable vulnerability”.

“Vulnerability functions” are the key element for new applications in the field of seismic scenarios and risk assessment. Also loss assessment – traditionally a field of the insurance industry – is now becoming a topic for local authorities and decision makers. A number of studies towards realistic assessment of damage potentials were performed in Europe as joint efforts between seismologists and engineers.

There is a general need

• to prepare refinements of the vulnerability table of the EMS for special purposes,
• to evaluate the levels of ERD provided by seismic building codes,
• to analyse the damage grades for further buildings,
• to pronounce the relevance of macroseismic maps for earthquake engineering purposes,
• to compare intensity-based hazard assessments and empirical scenarios in terms of intensities with magnitude-based hazard assessments and analytical vulnerability assignments (in terms of capacity curves) and, therefore,
• to describe damage pattern and damage states on the basis of EMS-damage grades. 

On the other side, there are further developments which have to be highlighted, like:

• the introduction of formalized procedures (algorithms) for computerized macroseismic intensity assignments,
• the widespread use of internet data compilations to derive shake maps, 
• the latest developments to derive macroseismic magnitudes for historical earthquakes.

It is intended to use the workshop for the preparation of Special Theme Sessions at the 1EECS and 13ECEE to be held in Geneva, Switzerland in 2006 to focus the discussion around EMS-98 applications and to summarize the state of knowledge.

Statements as working thesis:

3   Experience and fields of application

There are different results of field surveys which are mainly related to Turkish (Greek) earthquakes.

There should be results from the last moderate Earthquakes in France, Germany and Switzerland. No results are still published.

There is neither a general overview of world-wide use nor any feedback.

Intensity remarkably has lost its importance in engineering design practice due to the harmonization of European building codes and its strict orientation on ground acceleration as the main hazard describing parameter.

There is a loss of capacity due to the break-down of the former socialist countries.  

There are critical and contradictory comments concerning the scale, in some European countries still former scales (MM, MSK) are used. 

There are efforts against the scale (Russian side).

There are additions and extensions of the scale which are outside of the intended scope of application and which may lead to a step backward.

Several research projects are related to risk assessment on the basis of EMS-vulnerability functions (empirical approach) which in some cases are compared to analytical approaches (using capacity curves). The main interest is related to the vulnerability functions.

4   Problems

• Conversion between intensity scales
• Relevance of intensity maps for earthquake engineering: modern building codes are mainly related to magnitudes because of the availability of attenuation functions
• Relations between intensity and recorded ground motion data

In subchapter 4.2 "Correlations with ground motion parameters” we wrote that those correlations show very large scatter and for this reason, no attempt to include a comparative table of intensity and ground motion parameters has been made. This subject is still an area of active research.”

Question: Is it really?

• Introduction of formalized procedures (or algorithms) for computerised macroseismic intensity evaluation

The widespread use of internet data to derive shake maps becomes a new field of short-time intensity predictions while calibrating recorded ground motion coming from networks of recording instruments with effects coming from untrained data providers.

Question: Is it the required procedure? Or is the formalism related to the use of intensity descriptors leading to a weighted intensity value with indication of scatter or uncertainty?

Within the introduction of EMS-98 it is emphazised that further macroseismic practice may enable a deeper insight into the complex matters of assigning intensity. Future applications on future needs might be the basis for further improvement of this new tool.

• Practical application of the scale requires a limited knowledge of earthquake-resistant design principles
• use of monumental (churches) and other buildings
• the evaluation of buildings with respect to vulnerability classes
• the assignment of the appropriate damage grade

5   Progress in major topics

• For different traditional and modern buildings types a refinement of the vulnerability table could be reached.

For Central Asia:

Schwarz, J., Kaufmann, Ch., Langhammer, T., Swain, T.M., Khakimov, Sh., Tulaganov, B. (2004): Evaluation and strengthening of public buildings after the Kamashi (Uzbekistan) earthquakes in 2000 and 2001. Proceedings of the 4th International Conference on Building with Earth (LEHM 2004), Dachverband Lehm, 234--247.

Schwarz, J., Kaufmann, Ch., Langhammer, T., Swain, T.M., Khakimov, Sh., Tulaganov, B. (2004): Evaluation and strengthening of public buildings after the Kamashi (Uzbekistan) earthquakes in 2000 and 2001. Proceedings of the 13th World Conference on Earthquake Engineering (WCEE), Vancouver/Canada 2004. Paper No. 222.

For South America:

Lang, D.H., Raschke, M., Schwarz, J. (2004): The Cariaco, Venezuela, earthquake of July 09, 1997: strong-motion recordings, site response studies and macroseismic investigations. Schriften der Bauhaus-Universität Weimar 116 (2004): 35--51.

For Turkey:

Abrahamczyk, L., Schott, C., Schwarz, J., Swain, T.M. (2004): Vulnerability of RC frame structures in Turkish earthquake regions (Part II): Modeling and analysis. Proceedings of the 13th World Conference on Earthquake Engineering, Vancouver/Canada, 2004.

Lang, D.H., Ende, C., Schwarz, J. (2004): Vulnerability of RC frame structures in Turkish earthquake regions (Part I): Instrumental testing. Proceedings of the 13th World Conference on Earthquake Engineering, Vancouver/Canada, 2004.

The list has to be continued.  Further contributions are highly appreciated (should be sent by email: to schwarz@bauing.uni-weimar.de).

6   Check of previous ambitions

Coming back to the EMS-92 and the recommended fields of improvement:

 

Proposal	Topic	State 2005
Table B-1	vulnerability functions (of similar shape for each or different builing type(s) belonging to the same vulnerability class)	see comment 1
Table B-2	levels of ERD provided by European countries and their seismic codes	?
Table B-4	illustrations of damage pattern	?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Comment 1:

The use of statistical results of damage surveys is regarded to be “the key for introducing new building types as well as for better correlating particular building types with the most likely or probable vulnerability”. According to my rather limited knowledge such contributions are provided (among others) by EDAC for the region of Central Asia, where traditional (adobe) building types experienced a further subdivision.

(Finally, Schwarz et al. (2004) contributed to those typical vulnerability classes also for different strengthening techniques, see cover illustration.)

Preliminary programme

Thursday, October 13, 2005:

10.00 – 17.00: Discussion *

19.00 Evening reception (Dinner)

Friday, October 14, 2005:

09.00 –16.00: Conclusions and preparation of Special Theme Sessions in Geneva 2005 *

[*Note: breaks for coffee and lunch are foreseen.]