不同性能水平下600 MPa级高强钢筋混凝土柱位移角限值研究

STUDY ON DRIFT RATIO LIMITS OF 600 MPA GRADE HIGHSTRENGTH STEEL BARS REINFORCED CONCRETE COLUMNS AT DIFFERENT PERFORMANCE LEVELS

基于性能抗震设计思想的600 MPa级高强钢筋混凝土柱位移角限值研究,对于推广高强钢筋混凝土柱的应用至关重要。通过17根HTRB630高强钢筋混凝土柱试件和3根HRB400钢筋混凝土柱试件的拟静力试验研究了其抗震性能。与HRB400钢筋混凝土柱相比,HTRB630高强钢筋混凝土柱的滞回曲线的形状没有发生明显改变,试件具有较好的承载能力和延性。将基于Kunnath损伤模型计算的损伤指数与试验中测量的损伤指数范围进行了比较,结果表明,Kunnath损伤模型可以准确计算HTRB630高强钢筋混凝土柱的损伤指标。根据HTRB630高强钢筋混凝土柱的破坏特点,以屈服点、峰值点和极限点作为高强钢筋混凝土柱的性能水平控制点。基于性能抗震设计的思想,将600 MPa级高强钢筋混凝土柱的性能水平划分为5个性能水平,即正常使用、暂时使用、修复后使用、生命安全和接近倒塌性能水平。结合参考文献中600 MPa级高强钢筋混凝土柱的试验数据,对65个600 MPa级高强钢筋混凝土柱各特征点的位移角进行了相对频率统计分析,得到了600 MPa级高强钢筋混凝土柱在暂时使用、修复后使用和接近倒塌3个性能水平下具有超过90%安全保证率的位移角限值分别为1/150、1/80和1/60。

Within the context of the performance-based seismic design,the study on drift ratio limits of 600 MPa grade high-strength steel bars reinforced concrete columns is very important to popularize the application of high-strength reinforced concrete columns.The investigation of seismic performance is thusly performed for 17 HTRB630 high-strength steel bars reinforced concrete columns and 3 HRB400 steel bars reinforced concrete columns through quasi-static tests.Compared with the HRB400 steel bars reinforced concrete column,the shape of the hysteresis curve of the HTRB630 high-strength steel bars reinforced concrete column does not change significantly,and the displacement ductility coefficient of the specimen increases.The damage indexes calculated using the Kunnath damage model are compared with the range of damage indexes measured in the test to illustrate that the accuracy of the Kunnath damage model.According to the failure characteristics of HTRB630 highstrength steel bars reinforced concrete columns,the yield point,peak point and limit point are used as the performance level control points of high-strength reinforced concrete columns.Based on the idea of performancebased seismic design,the performance levels of 600 MPa high-strength reinforced concrete columns are divided into five performance levels,namely normal operation performance level,temporary operation performance level,reparable operation performance level,life safety performance level and collapse prevention performance level.Combined with the experimental data of 600 MPa grade high-strength steel bars reinforced concrete columns in the references,the relative frequency statistical analysis is carried out on the drift ratios of each characteristic point of 65 high-strength reinforced concrete columns of 600 MPa grade.The drift ratio limits with more than 90%safety assurance rate at the three performance levels of temporary operation,reparable operation and collapse prevention are 1/150,1/80 and 1/60,respectively.