Research On Deformation Index Limits Of SRC Members Based On Experimental Database

Since of high strength and good ductility,steel reinforced concrete structure is widely used in struction design,especially in high-rise buildings which have high seismic performance requirements.In recent years,performance-based seismic design in architectural structure has caused widely concerns.As result,for reinforced concrete structure there is mature research results can be applied to practical structure.However,for Steel reinforced concrete there is no mature deformation limits result which has largely limited performance-based seismic design for further popularization and application.In order to introduce performance-based seismic design method to steel reinforced concrete structure,this paper studies deformation limits of steel reinforced concrete components(beams,columns and shear walls).The main research work and achievements are as follows:(1)The method of determining the deformation limits of SRC components was put forward.On the basis of current national codes of China,the seismic performance states of SRC components is divided into 7 parts,namely,“intact”,“slightly damaged”,“slightly-moderately damaged”,“moderately damaged”,“severe-moderately damaged”,“severe damaged”,and “invalid”.According to the skeleton curve of SRC components in experiments,a method which takes drift angle of components as deformation performance index was put forward to define deformation limits of SRC components of each performance state on the basis of 3 key performance points.(2)The experimental database of SRC components in deformation performance experiments were established.By collecting relevant literature,experiment data of totally 94 SRC beams,246 SRC columns and 56 SRC shear walls were extracted.For each SRC component,experiment parameter,literature parameter and calculation parameter were collected to form the experimental database of SRC components.(3)The method of dividing the failure modes of SRC components was put forward.Based on flexural shear ratio and shear span ratio,the failure modes of SRC components are controlled by bending failure,bending-shear failure and shear failure.By comparison with actual failure mode,the method of dividing the failure modes of SRC components has a good guarantee rate.(4)The deformation limits system of SRC components was established.Based on the experimental database of SRC components,target exceedance probability was set.Regression formula of key performance in each failure mode is obtained by regression analysis.In the end,deformation limits system of SRC components which is reasonable and satisfied target exceedance probability are established.The deformation limits of SRC components proposed in this paper further quantifies the deformation capacity of components and makes up the shortage of seismic performance assessment of components based on bearing capacity in Chinese codes.It provides a theoretical basis for realizing performance-based seismic design and assessment on components level.