دانلود رایگان مقاله انگلیسی رفتار لرزه ای دیوارهای برشی با ستونهای CFST مرزی و صفحات چندگانه جاسازی شده - الزویر 2018

ABSTRACT

In this study, an innovative composite shear wall, comprised of boundary Concrete Filled Steel Tubular (CFST) columns, and Reinforced Concrete (RC) walls embedded with multiple steel plates has been developed. Seven specimens were investigated by cyclic loading tests. The parameters were the type of the boundary CFST columns, the number of multiple steel plates and the axial force ratio. There were two loading stages for the tests. During stage 1, the specimens were tested until a 2.0% drift ratio was attained. After stage 1, damaged specimens were retrofitted and tested in stage 2. The failure characteristics, hysteretic behavior, strength and deformation, strains, energy dissipation capacity and stiffness were studied. The results show that the hysteresis curves of the innovative shear walls were stable. The embedded multiple steel plates had a considerable effect on the seismic behavior of the innovative shear walls, and the strength increased with increasing number of steel plates. There was no considerable difference in the effect on seismic behavior for the different types of the boundary CFST columns. The developed shear walls, after retrofitting, were shown to satisfy seismic requirements. Finally, an evaluation method for the ultimate strength of the shear walls was developed with adequate accuracy.

Conclusions

An innovative composite shear wall composed of boundary CFST columns, embedded multiple steel plates, and RC walls has been developed. A total of seven specimens were designed and fabricated. Cyclic loading tests under two loading stages were carried out. Based on this study, the main conclusions are:

(1) The developed innovative composite shear walls with multiple steel plates had stable hysteretic curves.

(2) The number of embedded multiple steel plates considerably affected the seismic behavior of the shear wall. Specimen S3N1 with three multiple steel plates was the most cost-effective with respect to seismic behavior.

(3) The effect of the two types of boundary CFST columns considered, square and circular on the seismic behavior of the wall were similar. Both types of boundary CFST columns can be used to suit the construction needs.

(4) Retrofitting of the innovative shear walls was conducted after the first stage of loading and it considerably enhanced the behavior of the damaged walls. However, designers of the retrofit should assure that the strength of the retrofitting steel plate matches the strength of the shear wall.

(5) An evaluation method for the ultimate strength of the proposed shear wall was developed.

This method showed an adequate accuracy in the evaluation of the ultimate strength. The present paper revealed the advantages and behaviors of the developed shear walls with multiple steel plates subjected to cyclic tests. However, more experimental and analytical studies are needed to develop design provisions and theoretical models for such walls.