Seismic Damage Experiment Investigation And Performance Assessment Method For RC Column

The damage performance of the basic components is an important research content of design method based on performance. It has the important theory significance to study the RC column’damage evolution law and establish reasonable damage assessment method, as the RC column is an important class of anti lateral force component. In this paper, combined with acoustic emission monitoring technology, the damage evolution test of RC column is carried out and the RC column injury performance level is established by using probability and statistics method. The damage model is put forward based on acoustic emission monitoring results. The main research work as follows:Firstly, the quasi static low cycle repeated load test of RC column is studied. Considering the AE technology can monitor the concrete damage progress all the time, the RC column’s internal damage is monitored by AE instrument in the experiment. The specimens’seismic performance got from the experiment analysis such as the strain, load-displacement hysteretic curve, skeleton curve, ductility and so on. Through the careful observation of RC columns’ damage progress and the research of the features of curve for ring count rate to time, the law of ductile member’s damage evolution can be got.Secondly, understanding deeply the damage evolution law of RC column and considering the methord of damage performance point determined in the American Building Reinforcement Standard (ATC-40) and China Code for Seismic Design of building (GB50011-2010), five damage performance point are selected as follows:the first tension yielding of longitudinal reinforcement, the crushing of protective layer of concrete, the spalling ing of protective layer of concrete, longitudinal reinforcement buckling or stirrup fracture, the core area of concrete crushing. The test data of 55 rectangle columns’and 54 circle columns destroyed in ductility mode collected from the PEER database are used to calculated the five damage performance point value. Based on the probability statistics analysis method, the average value, standard deviation and the confidence upper limit damage value with 95% probability for each performance level of rectangle column and circle column are all determined. Thus, the probabilistic damage performance level of RC column is established.Finally, taking into the AE cumulative counts is the result of the total counts of the acoustic signal which reflecting the RC column damage development process, the RC column damage index model is putted forward bending on the AE cumulative counts parameter. Five damage values on damage performance levels are calculated by the ratio of the AE cumulative counts and total AE cumulative counts. By the contrast with the statistics damage values, the results show that the damage index model based on the cumulative counts parameters can evaluate the damage of the RC column correctly.