Study On Quasi-Static Seismic Resistance Behavior Of Steel-Fiber High-Strength Prestressed Concrete Flat-Beam Frame Structure

As a new kind of structure, the reinforce concrete flat-beam frame structure reduces the floor height and totle height of building efficiently, cuts down the internal force of structures caused by wind load and seismic effect, economizes the building costs. Especially, at the condition of the totle height of building being controlled, this structure is still provided with notable technology and economic benefit. But because the rigidity of the flat-beam is small, sometimes we need to use the prestressed steel to control the flexibility of the flat-beam and the width of the crack. At the same time, it brings the greater displacement reaction, lower energy-dissipation capacity and badly ductility ability etc. The unbonded partially prestressed concrete flat-beam frame structure has been used in the practice project in our country, but the aseismatic study of this structure is not perfect at present, study on theory is lagged behind the demand of engineering apply. It has important theoretic meaning and applied value to go deep into the examinational study about the prestressed concrete flat-beam frame structures.This thesis sums up the study of the RC flat-beam frame structure, the PC frame structure, the steel-fiber concrete, the performance of the steel-fiber concrete and its influence to the seismic resistance of the frame. Based on the previous research results, the test study on quasi-static seismic resistance behavior of the monolayer and single-stride prestressed concrete flat-beam frame structures are mostly carried through. The low-cyclic reversed loading test of two frames with the same size and the same intension grade are conducted. One frame is made of ordinary concrete, the other is made of steel-fiber concrete. The aseismatic behaviors of the two frames are analyzed and compared, with emphases on failure mechanism, hysteretic property, displacement ductility, energy-dissipation capacity as well as stiffness degeneration, etc, to find the influence of steel-fiber concrete to the aseismatic behaviors of the prestressed concrete flat-beam frame structures. At the same time, computer simulation of the structureswith the non-linearity finity element software ADINA is carried out to compare with the result of the examination, study the influence of behaviors of the flat-frame because of the different prestressing ratio(PPR) and the dosage of steel-fiber.The results show, when steel-fiber concrete is used in the frame structure, the PC concrete flat-beam frames can have the more satisfiable aseismatic behaviors. When designed rationally, the frames can form beam hinge energy-dissipation machine and total destroy mechanism. The structural system have considerable energy-dissipation capacity and the strong seismic resistance behavior, so can be generalized and used in medium seismic zones. Through the compare of the resule of computer simulation and the examination, we can fine that the craze destroy form and the failure load etc. of the frame are inosculate basically. This fruit of the study can provides new methods to the supplement of concerned criterion and the design about the flat-beam frame structure...