THE MINIMUM DEPTH OF THE GIRDER OF PRESTRESSED CONCRETE FRAME DUE TO REQUIREMENT OF PRESTRESS DEGREE FOR ASEISMIC DESIGN

Due to the high-strength steel and prestress, the ductility of section of prestressed concrete frame becomes small. The ductility can be improved by adopting partial prestressed concrete section. In order to improve aseismic level of prestressed concrete frame, the prestress degree and reinforcement percentage will be limited. To form a beam hinging collapse mechanism, the limit strength of beam should be controlled. In the light of this thought, the codes of foreign countries have contained the requirement of aseismic design in the end section of frame beam. This requirement is incompatible with the crack resistance requirement, which results in the increase in beam height.This paper puts forward the design thought of a beam hinging collapse mechanism with non- end- section plastic hinges under strong earthquake and the aseismic capability of a prestressed concrete frame by this design thought is also demonstrated by an example.