A Study On Some Problems About Design And Construction In A Long Span Prestressed Concrete Frame

The technique of prestressed concrete has been already applied more and more extensively in civil engineering realm. With the development of our society, more and more long span and large column-grid frame is to be applied in house building, public building and factory building. Because of its advantages to resolve the lacking of stiffness of concrete beam, to nicely control the development of the cracks and deflection, and also because of its nice economy in use, prestressed concrete has been widely used in long span continuous frame.However, the technique of prestressed concrete also has some problems in design and construction. For example, the large friction loss of prestressed tendons, complex anchorage bearing joint, the problem of cracks in large area structure ,axial compress of long span continuous beam under prestress. All those hinder its use in long span structure. Until now days, the cognition about the behavior of such structure under loads is not enough for the realm of prestressed concrete of all the world.Different from the construction of RC, the construction of PC needs high technique. there is a close relation between design and construction, and different manner of construction would result in different internal force of structure.This thesis aims to analyze how to select and assign prestressed tendon, how to design anchorage bearing joint, how to control the crack, how to calculate the axial prestressed force and the third moment and how to design the edge column of top layer. On the base of the research in and out our country and construction of the prestressed structure, some helpful conclusion and suggestion are presented, which is suggestive for the design and construction of long span continuous prestressed concrete frame.