An approach to the capacity design of reinforced concrete chimneys
Rosetnic V.
CICIND REPORT Vol. 19, No. 2, 2003
Order No: CR-242
Capacity design procedures newly introduced in chimney codes such as EC8 Part 3 and the CICIND Model Code are considered to be partly inconsistent with stated principles of the philosophy, in that the position of plastic hinge regions is either ineffective (EC8) or may lead to instability in the structural system (CICIND). A numerical study in which 5 representative Romanian chimneys (heights 60m..250m) are confronted with 4 earthquake records typical for as many site conditions is introduced. The position of the plastic hinge region is varied in the central, immediately lower or immediately upper fifths. It is found that i) the effective plastic hinge region should be selected depending on the combination of chimney dynamic characteristics and site dominant period; ii) a unique value for the behaviour factor is not an ideal solution for all design situations: a flexible approach including a range of behaviour factor values appears to be more suitable.