Design and Plastic Analysis on Prestressed Concrete Frames with Non-End-Section Plastic Hinge of Beam Hinging Collapse Mechanism under Lateral Action of Earthquake

• Published in: Key engineering materials 2004-10, Vol.274-276, p.745-750
• Main Authors: Chen, Hua Fu, Chen, Xiao Bao, Ma, Hong Wang
• Format: Article
• Language: English
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.274-276.745

When designing a beam in prestressed concrete (PC) frames, the parameters such as size of beam section, amount of prestressing tendons and amount of ordinary reinforcing bars at an end section of the beam should be selected to meet the requirement of anti-crack in service, the requirements of bend strength and its ductility under seismic action and the restriction of prestress degree of the section for anti-seismic. In addition, under the designated severe earthquake plastic hinges should be developed in beams rather than columns of the frame in the light of the detailing philosophy of strong column-weak beam. For a frame of PC to be designed to survive under a severe earthquake, the beam with large size of section must generally be adopted. In order to get a prestressd concrete frame with smaller section of beam for a building structure in seismically active regions, a beam hinging collapse mechanism with non-end-section plastic hinges has been brought up by arranging a proper profile of prestressing tendons along the beam nearby the end-section. For the end section, it is not very hard to meet the requirements of anti-crack and the bearing capability by increasing the amounts of prestressing tendons and reinforcing bars. While for a non-end-section, where the prestressing tendons have been put near the center of the section, it is not a problem to meet the requirements of bend ductility and the restriction of prestress degree under earthquake action, for this section behaves like a non-PC section due to less deviation of prestressing force from the section centre. After generally proposing a procedure for designing a PC frame with non-end-section hinges, a typical example of PC frame has been designed. By inelastic push-over analysis and dynamic time history analysis, the plastic behaviors and energy dissipating mechanism of frames designed by traditional method and the proposed approach have been investigated, which has shown the effectiveness of PC frames with non-end-section hinges in controlling crack and resisting seismic action and the superiority in reducing height of beam section.