TASK GROUP (TG8): SEISMIC BEHAVIOUR OF IRREGULAR AND COMPLEX STRUCTURES

TG8 was established under the auspices of the European Association for Earthquake Engineering (EAEE) in August 1994 as a Working Group (WG12): Torsional Seismic Response of Structures. In 1995, upon the proposal of the Executive Committee, the scope of its activities was widened, and the WG was reorganised as Task Group (TG) 8: Seismic Behaviour of Irregular and Complex Structures. The purpose of the TG is to promote and coordinate research and to provide forums for scientific exchange in the field. TG8 is coordinated by Prof. A. Rutenberg (Israel), together with two co-convenors: Dr. A. Chandler (U.K), and Prof. R. Ramasco (Italy). The TG8 member roster is given in Appendix A.

The first task of TG8 was to compile a Bibliography which comprehensively covers publications on the nonlinear behaviour of asymmetric structures:

* Rutenberg, A., Chandler. A.M., Duan, X.N. and Correnza, J.C., "Nonlinear Seismic Response of Asymmetric Structures: Bibliography", Report for the EAEE Task Group 8: Behaviour of Irregular and Complex Structures. Technion - Israel Institute of Technology, Haifa, Israel, October 1995.

Three papers reviewing the setting up, management and priority research tasks of TG8, and giving critical reviews of the EC8 torsional provisions have been published since 1995:

TG8 organised a European Workshop on the Seismic Behaviour of Asymmetric and Setback Structures in Anacapri (Isle of Capri), Italy on October 4 -5 1996. The Workshop was hosted by the Department of Structural Analysis and Design, University of Naples Federico II. Twenty-two papers were presented at the Workshop. Circa 40 scientists from 12 countries participated. A Proceedings volume, published by the University of Naples, containing the 22 papers, was presented to all participants. (A limited number of copies may still be purchased from the University).

It is the view of many members of TG8 that the lack of experimental validation and substantiation of the theoretical research findings, on which most of the torsional provisions in seismic codes are based, is a serious limitation of the existing design approaches to this problem, and unless resolved it will continue to hamper the updating process for earthquake design provisions relating to irregular structures. In view of this, a preliminary proposal to carry out shaking table tests on scale models of asymmetric building structures was submitted by the undersigned to the appropriate committee of the EC. The proposal was approved for testing in the Earthquake Engineering Research Centre in Bristol. Design of the specimens to be tested is presently under way.

A second workshop, to be hosted by the Technical University of Istanbul, is slated for 1999, with tentative dates: October 8-10. A Proceedings volume will undoubtedly be published following the workshop.

It is planned to carry out the aforementioned tests in Bristol during the near future. At this juncture the tests are targeted for October 1998, with static pre-test to be carried out earlier. In fact, Dr. M. De Stefano and Dr. T. Trombetti have started work on the design of the models to be tested, and recently visited the Bristol facility. A follow up verification test program to be carried out at JRC Ispra is contemplated.

A program of future activities will be the main item on the agenda for the TG8 meeting during the 11th ECEE.

Prof.Dr.A.V.Rutenberg

TG8 Coordinator