N° 160.1983. Model Code for Seismic Design of Concrete Structures - Vol. 1 - Final Draft
This document represents the third and final step of a project started by CEB at the occasion of the International Symposium on " Structural Concrete under Seismic Actions" held in Rome, on May , 1979.
The vast experience of CEB with reinforced concrete , as well as his achievements in the process of rationalization of Codes , were then combined with the specialist knowledge of a group of experts representing all the major 'school s of thought' in the area of aseismic construction. The activity of this group has led to the two previous editions of this document, the first one appeared in March, 1980 (Bul 1. n. 133), the second one in March , 1982 ( Bu 11 . N. 149) .
The minor adjustments required after the second draft (improved cal ibration of some procedures , corrections of misprints , etc. ) would not have warranted the preparation of the present completely revised edition.
Why then a new version, if the technical content of the previous one was already essentially stablized? The answer lies in one activity CEB is pursing from some years now, i.e. the development of future Structural Codes. The trend is towards documents which are more "justificative" rather than "prescriptive ", providing the designer with the infonnation required for a fuller understanding of the design objectives, and of the means of implementing them through appropriate procedures and rules .
Al though to a les -than -full extent, this "performance oriented character", as it has become to be known , was already incorporated in the first two drafts of the document. The occasion was then taken to try to make its logic adhere more closely to the new lines, according to the sequence : requirements-design criteria-methods of assessment-practice.
Fu ture users wi ll say if the effort has been beneficial.
Whether the attempt was worthwhile there should be few doubts: in engineering ,practice only can validate new ideas .
Application of these ideas has made some compromise unavoidable: it is not easy to find a precise quantitative justification fo r all the good design rules inherired by experience, and the optimum balance between the parts dealing with general concepts and those intended for daily office use depend to a good extent on the type of Code user itself.
In any case , applicability and consistency of the document have not been left unchecked. A substanci al work of trial applications to frames and wall structures has been separately elaborated by four national groups : results and comments are reported in Bulletin n. 160 bis .
Paolo Emilio Pinto
Reporter of the CEB task group - SEISMIC DESIGN
