REPORT ON THE ACTIVITY OF TG5

VIBRATION BASE ISOLATION AND CONTROLLED STRUCTURES

General: During the last several years, different variants of global development directions have been evident in the field of seismic isolation of structures. Basically, the following three significant areas can be distinguished:

During the last several years, such general activities have clearly demonstrated that seismic isolation of structures is not only a research subject any more. Today, seismic isolation or seismic vibration control of structures is basically recognised as convenient practical technological alternative for successful earthquake protection of structures and equipment.

Application areas: In recent years, it is also evident that application areas of seismic isolation are becoming more wide and specific. Actually, the applicability of this technology is evident in:

Cost: One of the primer factors for limited application of seismic isolation in the past was the significant increase of the construction cost. However, this limitation has recently been largely reduced as a result of rapid technological achievements of production industries and advanced materials.

Low cost seismic isolation: An important element which should be mentioned is the rapid recent developments of the so-called low-cost seismic isolation system. This fact is very important since such technologies can provide intensive practical applications for seismic protection of common residential structures in developing countries without significant cost increase.

Combined systems: In addition to the classical seismic isolation, the development of the so called combined vibration control systems, including both seismic isolation and different types of distributed energy dissipaters in the structure have recently become very attractive.

Significant applications today: Up to date, significant practical application of seismic isolation has basically been restricted to several world countries (Europe - Italy, Asia, Japan, United States, New Zealand, etc.). However, apart from these leading countries, we can also recognise an increased interest in application of seismic isolation recently in many other countries exposed to serious seismic risk potential. It is necessary to firstly mention China, Russia, Iran, India, Greece, South American countries, countries of South Asia and many others. It is clear that the seismic isolation technology is rapidly becoming a construction alternative for the future effective seismic risk reduction on a world scale.

Although investigations in a field arousing a considerable interest are in question, the activities of TG5 have unfortunately been minimal for the last four years. The responsibility for this is certainly mainly borne by the chairman of this group, but it seems that there exist a number of other factors that more or less affect also the activity of the other groups.

I therefore suggest that the Board of our association considers and proposes certain changes in the organisational structure of EAEE and adapt it to the needs of the present relations in Europe. To that effect, the President of TG5 has submitted a rationale to the President and the Secretary General of EAEE.

Starting from the fact that TG5 covers two specific fields, i.e., vibration base isolation and controlled structures and that the companies dealing with development of materials, elements and technologies, the users of these products and finally the investigators are interested in these modern technologies of construction, the organisation of a group discussion - a colloquium on Application and Further Development of Vibration Base Isolation and Controlled Structures in Europe might be of an interest for all of them.

This colloquium can be realised in September 2000 under the auspices of the European Association of Earthquake Engineering in cooperation with the host scientific association. The decision on the host country should be made by Board of the EAEE and the chairman of TG5.

Should the EAEE board accepts this proposal, I am ready to be at disposal as to proposing the programme, the necessary time duration and the organisation of the proposed colloquium.

D r. Dimitar Jurukovski

Coordinator of TG5,