Analytical study on the effect of extreme seismic strains on the transverse buckling of ultra-reinforced seismic walls and their environmental design

Abstract

In the context of the present work, the influence of the degree of tension on the phenomenon of transverse instability of reinforced concrete seismic walls is examined. Useful conclusions are drawn regarding the influence of the degree of elongation on the phenomenon of transverse buckling. These conclusions are substantiated both experimentally and analytically, as the results of the experiments are compared with the corresponding results of the analytical investigation. Moreover, some thoughts on a more environmental design of R/C seismic walls are stated. The present investigation is both experimental and analytical and consists of 4 test specimens. These specimens simulate the extreme boundary edges of structural walls. All columns simulate only the extreme reinforced areas of the walls, in order to study the basic mechanism of the phenomenon. The detailing of the specimens consists of 6 rebars with a diameter of 12 mm for each bar. The geometric dimensions are the same for all specimens. What differentiates the specimens from each other is the degree of tension they have sustained. More specifically, the tensile degrees used are 10‰, 20‰, 30‰ and 50‰. The loading stages of each specimen for all specimens are as follows: (a) Uniaxial central tensile loading on each test specimen apart from the specimen sustained 0‰ degree of tension; (b) Uniaxial central compression loading on each specimen till its failure due to buckling or due to an excess of its cross-section compressive strength. The present study focuses on the tensile loading stage only. Extreme tensile strengths are also used, e.g., 30‰ and 50‰, in order to take into account, the cases of extreme seismic excitations. The experimental study is followed by the numerical investigation of these 4 specimens using appropriate statistical software and finite elements.