Study On Seismic Performance Of Frame Structure Of Precast Prestressed Truss-type Steel Reinforced Concrete

Combined with prestressed steel reinforced concrete structure's advantage of large span,high bearing force and small cross-section size,with the objective of enhancing the anti-seismic property of frame structure,this paper proposed a new precast prestressed truss-type steel reinforced concrete frame structure,relevant test research and theoretical calculation analysis were carried out.The truss-type steel in the precast prestressed truss-type steel reinforced concrete structure is integrated from chord member,web member and gusset plate by means of welding,and it is applied with appropriate prestress in the large-span structure or structure under heavy load,and finally it becomes the precast prestressed truss-type steel reinforced concrete structure,it can be applied in most of structure systems such as industrial plant,housing and bridge.This paper mainly completes the following work:(1)Anti-seismic property test of two-beam truss-type steel reinforced concrete portal frame test-piece under horizontal low-cycle reciprocating load was firstly conducted,test process and damage form were observed,test-piece's anti-seismic property such as hysteresis characteristics,skeleton curve,rigidity degeneration,energy-dissipating capacity and residual deformation was studied,meanwhile,strain change rule of chord member angle iron and diagonal web member angle iron of beam end and heel were analyzed,yield hinge order was derived.The research results show that two-beam test-piece's load-displacement hysteretic curve is plump without obvious pinch phenomenon,which indicates a good anti-seismic property,and prestress was applied without impact on its ductility,energy-dissipating capacity and deformation recovery performance;applying of prestress can postpone appearance and extension of crack in the process of loading;two-beam portal frame test-piece has the same order of yield hinge,namely "beam end before heel",which indicates that this frame structure complies with the design of "strong column and weak beam,;(2)Based on three-dimensional element theory,with ABAQUS finite element software,finite element simulation of mechanical properties was conducted for truss steel-bar concrete portal frame test-piece model under horizontal load.The stimulation results show that test-piece damage form,limit load and skeleton curve derived with finite element simulation analytical method were comparatively identical to measured results;(3)Parameter analysis was conducted for hysteresis characteristics of the precast prestressed truss steel-bar concrete frame structure.The results show that the most critical factor is column slenderness ratio and axial load ratio,with increasing of column slenderness ratio,frame bearing force will lower,peak value load becomes smaller,lateral rigidity is reduced,and displacement ductility rises,and with increasing of axial load ratio,frame displacement becomes smaller,and deformation becomes poor;(4)On the basis of parameter analysis results,restoring force model of single-layer single-span precast prestressed truss steel-bar concrete frame structure was derived through regression,this model can be used to make a better forecast of hysteresis characteristics of such frame structure under horizontal load.