Research On Seismic Performance Of Concrete Column With Central Reinforcement

In the frame structure and shear wall structure,ordinary reinforced concrete columns play an important role,because the column is subjected to vertical and horizontal loads at the same time,which makes the force and the earthquake resistance mechanism of the column more complicated.From the post-earthquake survey,it was found that ordinary reinforced concrete destruction of the column in the earthquake is more serious,and then affect the safety of the entire structure.In order to improve the seismic performance of ordinary reinforced concrete columns,reasonable measures can be taken from design and construction,so as to ensure that ordinary reinforced concrete columns meet the corresponding seismic performance.In this paper,from the aspect of construction,reinforcement of the cross-section of ordinary reinforced concrete columns are reinforced to form concrete column with central reinforcement,and the seismic performance of concrete column with central reinforcement is mainly studied.The main content of this article includes:(1)Four common reinforced concrete columns were modeled using OpenSees finite element software to obtain the hysteresis curve under low cyclic reversed loading.The simulation results were compared with the experimental results to verify the modeling method used in the simulation.The correctness of the material constitution ensures the reliability of the simulation results.In addition,the influence of the number of integration points and grid division on the simulation results is studied and the corresponding recommended values are given.(2)12 concrete columns with central reinforcement were designed for low-cycle repeated loading tests.The effects of axial compression ratio,shear-span ratio,reinforcement ratio in the core zone,core area and stirrup spacing on the seismic performance of concrete columns with central reinforcement were analyzed.Intensity degradation,stiffness degradation,ductility and energy consumption are evaluated for seismic performance of concrete columns with central reinforcement.At the same time,theseismic performance of concrete columns with central reinforcement and ordinary reinforced concrete columns was compared and analyzed.The results showed that the maximum strength and energy consumption of concrete columns with central reinforcement were increased by 36.5% and 24% respectively,indicating that the concrete column with central reinforcement can Effectively improve the column’s bearing capacity and seismic performance.(3)In order to more accurately study the post-yield seismic performance of concrete columns with central reinforcement,when considering the damage model and the buckling model of the steel reinforcement in the modeling,the simulation results are optimized and more consistent with the test results;comparing the optimization results,we can see that considering the reinforcement buckling The model is more optimized for simulation results.(4)Based on summarizing the shear capacity of reinforced concrete columns at home and abroad,combined with the design specifications of China and the simulation values of12 concrete columns with central reinforcement,the calculation formula for the shear capacity of concrete column with central reinforcement is proposed.The results show that the calculated values of the concrete columns with central reinforcement are in good agreement with the simulated values;the rationality of the proposed formula is verified and can be used as reference by the designer.