Seismic Behavior Of Prestressed Concrete Frame Structures With Large Span

The span of structure is bigger and bigger, as the improvement of modern building structure by using functional requirements, prestressed concrete structures being applied in the building structure because of large span, small size etc. As a result of the prestressed concrete structure with low damping, the use of high strength reinforced bar decreasing its structural plasticity, lead to a large prestressed concrete structures under the action of earthquake response, it’s bad for seismic performance; but, prestressed concrete structure can increase the using span of structural, make a relatively small cross section size with same span, the corresponding stiffness is smaller, long prestressed structure vibration period, subjected to earthquake is also small; the application of prestressed concrete structure in the earthquake has always been controversial.In this paper, for large-span prestressed concrete structure doing pushover analysis of the role of different working conditions with SAP2000, from the Inter-story Displacement Angle, the mechanism of plastic hinge and ductility to analyze the seismic behavior. The main conclusions are as follows:1. Can’t increase prestressed concrete to control the cracking of concrete beam and deflection simply for seismic design of large span prestressed beam, prestressed degree must conform to the specification limits, to improve the ductility of the member with reducing the number of prestressed tendons in prestressed component appropriate;2. Under rare earthquake, large-span prestressed concrete structures of maximum Inter-story Displacement Angle within the limits specified in specifications, in line with the relativity to no Collapsing with strong earthquake for earthquake resistance protection, at the same time, according to the hinge order that conform to the requirements for the design of the strong column-weak beam;3. At the ends of the large span prestressed beam plastic hinge as seismic action towards the beam span of migration, both ends of a plastic hinge is a negative, easily lead to negative hinge hinge rotation ability weak premature failure;4.To determine the weak parts of the structure using the interlayer displacement angle curve, the sequence of plastic hinge and the changing of plastic hinge in the process of seismic action determine, and strengthening design on it;5. The ductility of the prestressed concrete structures in addition to the ductility coefficient of evaluation index, but also through the structure section curvature change rate to evaluate, the curvature rate and structure ductility is proportional to the relationship, to a certain extent.