Experimental Research On Seismic Capacity Of Precast Prestressed Short Pier Shear Wall Structure

Recent years the short pier shear wall has been one kind of new structure systems, in which own weight is lighter, the ability to keep warm is better, the plane layout is more flexible, the construction function is excellent, compared with the ordinary shear wall structure. It develops rapidly, and its seismic performance has attracted the attention of the structure engineers and researchers. Some related earthquake damages and shock tests have indicated that the primary earthquake-resistance positions of the short pier shear walls are the panel joints of the tie beams. Under the strong (medium and major) earthquake, the structures form the"beam end plastic hinge failure mechanism", and its energy dissipation is assumed by the plastic deformation of the shear walls and tie beams. The damages of the structures are serious, so the retrofitting of the structures is difficult and expensive.Precast concrete structures using post-tensioned prestressing tendons have advantages of precast systems ,such as high construction speed ,low pollution ,assurance of quality and durability, etc. Furthermore, it also has following merits of its own First, it's helpful to realize the energy dissipation mechanism set beforehand. Second, the damage of structure induced by earthquake is easy to estimate. Third, it has high self-centering capacity and small residual displacement after earthquake, and can be repaired conveniently.In order to effectively control the damage of the short pier shear wall, fist time the precast and post-tensioned technology is introduced into the short pier shear wall based on reading the documents home and abroad. Two precast prestressed short pier shear walls are made, and their seismic performance is studied under cyclic loading.The main contents of this paper can be concluded as following:(1) The application of precast and prestressing used in short pier shear wall is probed. New-style precast short pier shear wall using post-tensioned prestressing tendons are made.(2)The form of panel joint applicable to the short pier shear wall and the collocation method of post-tensioned prestressing tendons are studied.(3)Based on the low-cyclic reversed loading test, the failure mechanism, hysteretic property, displacement ductility, energy dissipation capacity, skeleton curve as well as bearing capacity and stiffness degeneration of the structure is analyzed.(4)The stress behavior of unbonded post-tensioned prestressing tendons is measured during the experiment and its varying discipline is summarized.(5)The computing formula of bend and crack resistance capability are deduced, and the press frication action of the gap is analyzed.The research shows that the precast prestressed short pier shear wall using post-tensioned prestressing tendons can realize the energy dissipation mechanism set beforehand with fewer damages. Due to prestress exerted, the structure possesses satisfying self-centering capability ,can be retrofitted and fixed up expediently after earthquake.