N° 161. 1983. Response of Reinforced Concrete Critical Regions under Large Amplitude Reversed Actions
Conventionally, structural design is meant to be synonymous to the analysis and dimensioning against monotonic actions. However it is in the nature of many loads and deformations applied on real structures to be of a cyclic character, with low or high frequencies. This may be the case of temperature effects, traffic leads, displacements imposed by machine foundations, wind and wave actions , seismic actions and the like. In this connection, i t is worth reminding here that in the specific case of cyclic accidental actions, large amplitude reversals are expected to apply on plastified critical regions of building elements. Therefore, the Mechanics of severely "damaged" regions, under cyclic combined action-effects, becomes of great practical importance;
Inspite this, actual Codes do not contain detailed recommendations regarding stiffness assessment and dimensioning of R.C. critical regions under cyclic actions, especially under large amplitude reversals.
The CEB Administrative Council, wi thin its policy for the new generation of Codes, has formed the GTG/10 in order to explore a part of the field related to cyclic a namely the respon.ctions, se of critical regions under large amplitude reversals. The Group has met five times (Athens May 1981, Lisboa Oct. 1981, München April 1982, Athens Sept'. 1982, Lausanne April 1983) , and has submitted to the Council a Draft Report; it has been decided to present a full Report in Prague during the 23d Plenary Session of CEB.
The complexity of the subject and the short time available are some of the difficulties encountered. However, it is hoped that this Document may be of some value:
- As a State of the Art Report
- In assisting design in some particular cases
- As an input (or reference document related) to future modifi- . cations of the CEB Seismic Annex.
- As prolegomena to the future, more systematic, activities of CEB in the field.
