DESIGN EQUATIONS FOR EVALUATION OF STRENGTH AND DEFORMATION CAPACITY FOR UNSTRENGTHENED AND FRP STRENGTHENED RC RECTANGULAR COLUMNS UNDER COMBINED BIAXIAL BENDING AND AXIAL LOAD
When assessing the seismic performance of existing reinforced concrete buildings designed according to obsolete codes, one can identify potentially dangerous situations that could result in catastrophic failures. A typical inadequacy lies in the so-called strong beam-weak column situation: columns are no so strength to force plastic hinge formation in beams and, if this is extended to all columns at a given floor, can lead to the development of a soft-storey mechanism. Such weaknesses should be eliminated by upgrading all weak columns in the zones of potential formation of plastic hinges so to increase their flexural capacity and to force plastic hinge formation in the beams. With this aim one or more layers of FRP could be wrapped longitudinally along the column at the end zones. Nevertheless, the flexural strengthening can reduce the elements deformation capacity. This paper, starting from previous authors works propose a simplified procedure for the assessment of flexural strength and deformation capacity of rc unstrengthened and FRP strengthened reinforced concrete rectangular columns. Approximate closed form equations are developed by which the flexural strength and section ultimate curvature are evaluated as a function of the normalized acting axial load and the geometrical and mechanical sections parameter. The proposed approach is compared with a fibre approach.
RC columns FRP-strengthening interaction domain biaxial bending closed-form equations seismic upgrade
G. Monti S. Alessandri
Dept. of Structural Engineering and Geotechnics, Sapienza, University of Rome, Rome, Italy
国际会议
14th World Conference on Earthquake Engineering(第十四届国际地震工程会议)
北京
英文
2008-10-12（万方平台首次上网日期，不代表论文的发表时间）