Study On Seismic Performance For Prefabricated Porous Shear Wall Of Vertical Connection By Prestressed

At present, most of the multilayer and high-rise residential buildings are cast-in-place concrete structure, With the improvement of people’s demand for housing, The weakness of this structure system gradually appeared, this ruggedly typed production mode restrict the further development of the housing industry in our country, housing industrialization make the quality residence balanced, and can make the production mode of the residence into technology intensive from labor intensive. The superiorities of the prefabricate assembly reinforced concrete structure are:high production efficiency、convenient and fast、shorten the construction period、easily realize modular、standardization、large-scale production and improve the quality level. But in our country, the research of the precast prestressing shear wall still in initial stage, needing further studied.In this paper, we select the prefabricated porous shear wall as the object, the most common form of shear wall in residential buildings,and we use finite element software ABAQUS to do a nonlinear analysis about the specimens’ bearing capacity and deformation capacity. We change the parameter like the connection form of the precast concrete porous shear wall, concrete strength grade, hole ratio, the level of shear wall, vertical reinforcement ratio and volumetric percentages of stirrups, we make comparisons of the failure mode, skeleton curve,bearing capacity, stiffness degradation,energy dissipation capacity and ductility performance after changing every parameter, and we can know the influence of every parameter on the seismic performance.1、Through the simulation, we can see the ductility of the prefabricated porous shear wall is lower than the precast common reinforced porous shear wall, but when it unloads in elastic stage,the specimen has good restoring ability;the prestressing concrete can be used in the connection of vertical joint in the prefabricated porous shear wall; if the effective prestress is to small, the good effect of the prestress to the using performance will not be give full play. Takin the bearing capacity and ductility performance into consideration, we suggest the tension contrc stress should control in0.5fptk or so in practical engineering.2、Through the simulation, we can see the concrete strength grade in the range o C30～C50,the bearing capacity of the prefabricated porous shear wall of vertical connection b; increase as the concrete strength grade increasing, while the ductility performance decrease compared the concrete strength grade in the range of C40～C50,increase amplitude of th ultimate load is greater when the concrete strength grade in the range of C30～C40,so when th concrete strength grade is under C40,we can increase the concrete strength grade to increase th bearing capacity.3、Through the simulation, we can see the vertical prestress connection prefabricated porou shear wall’s bearing capacity decrease and the ductility performance improve as the hole rati increasing, when the hole ratio is in the range of0-17.55%, cracking load and ultimat displacement increase gradually as hole ratio increasing, it approximate a horizontal line, th ultimate displacement increase as the hole ratio increase, ultimate load decrease as the hole ratii increase. When the hole ratio is in the range of17.5%～22.3%, decrease amplitude of crackin load and cracking displacement is obvious than the increase amplitude before, ultimat displacement increase sharply as the hole ratio increase, ultimate load decrease sharply as hol ratio increasing. Synthesize consider the effect of the hole ratio on the seismic performance, s we suggest controlling the hole ratio of the vertical prestress connection prefabricated porou shear wall within17.5%in practical engineering.4、Axial compression ratio formula of the prestress porous shear wall considering the effec of the hole ratio: N-Axial pressure design value under Gravity load represent value fc—Axis of concrete compressive strength design value A-Total Section area ρc—hole ratio G1k—Standard weight of the wall(Don’t deduct the influence of the hole) G2k—Standard weight of the structure beside wallAxial compression ratio formula considering the effect of the hole ratio can provide reference to the design of other similar porous shear wall.Through the simulation, we can see as the axial compression ratio increasing, the cracking load. ultimate load. cracking displacement increase, hysteretic loop’area of the vertical prestress connection prefabricated porous shear wall reduced as the axial compression ratio increase, it leads to the ductility factor and seismic performance decrease. When the axial compression ratio is in the range of0.1-0.3,it has significant influence on seismic performance, and in range of0.3-0.5,the influence becomes smaller. So we suggest the axial compression should control in0.3or so, the axial compression ratio formula of shear wall can refer to the axial compression ratio formula of shear wall with hole.5、Through the simulation, we can see the increased ratio of the vertical reinforced have small influence on the structural behavior of the vertical prestress connection prefabricated porous shear wall; the increased ratio of the horizontal reinforced have influence on the structural behavior of the vertical prestress connection prefabricated porous shear wall, the bearing capacity increase as the ratio of the horizontal reinforced increase, but the growth is small, volumetric percentages of stirrups of the edge members have more influence on the structural performance than the horizontal reinforced, In practical engineering, we suggest the ratio of the vertical and horizontal reinforced value According to the structural requirements, when the members need strengthen, we should take the increasing the edge member’s stirrup into prior consideration. In the practical engineering using the precast prestressing concrete hollow-core slab shear wall, we suggest using the constructional reinforced, the section area not deduct the influence of the hole when calculating, it can Provide Reference to the reinforced ratio of other similar porous shear wall.