Research On Deformation Limits Of SRC Beam And Column Base On Experiment Data

Steel-Concrete beams and columns are main load-resistant components in high-rise and super high-rise buildings. However the current performance based seismic design method in the Chinese codes has not put forward the quantified criteria of the SRC beam and column performance. Consequently, it is unable to evaluate the performance of steel-concrete members under various levels of earthquake. Therefore,It is necessary to gain insight into the deformation limits of SRC beams and columns. Through the statistical research of a large amount of SRC components, the quantified deformation limits of SRC beams and columns are attained. The research mainly includes the following content:(1) Specimen information of 206 SRC columns and 157 beams are collected, but bias as well as inconsistency of definitions are found among the literatures the value of shear span ratio, moment shear ratio, axial load coefficient, transverse reinforcement ratio and steel ratio is recalculated and summarized.(2) Based on the specimens, the connection between failure modes and shear span ratio, moment shear ratio and axial load coefficient is analyzed. C lassification method of the failure modes of SRC beams and columns is put forward with parameters of shear span ratio and moment shear ratio. Regression analysis shows high rationality of the proposed method.(3) With reference to the literatures and the summary of phenomena related to different performance levels, the performance of the composite members are divided into 5 phases: intact, mild damage, medium damage, relatively severe damage and severe damage. Drift angles of these levels are determined based on the feature points of the skeleton curves.(4) The correlation between deformation limits of both columns and beams, and shear span ratio, axial load coefficient, moment shear ratio, transverse reinforcement ratio, reinforcement ratio and steel ratio under different failure modes is analyzed. The key parameter is determined. Criteria of deformation limits are put forward via statistical analysis, furthermore, the criteria is verified via 363 test specimens.(5) Via regression analysis, the correlation between deformation limits of SRC members and shear span ratio, moment shear ratio and other parameters are analyzed. moreover, 2 closed parameters are determined, fitting formulas of computing deformation limits of different members at different performance levels is also concluded.