我国规范抗震时程分析地震波选择比较研究

Comparative Study on Ground Motion Records Selection Methods in Codes for Structural Time-history Analysis

摘要:

时程分析是评估结构地震反应及性能的主要手段，其结果受输入地震波影响很大。对地震波输入规范条款进行了总结，辅以加权调幅法等以15层、30层钢筋混凝土结构为例，以最大层间位移角均值作为目标反应，将依不同规范及方法选取地震波所得的结构弹性和弹塑性时程反应结果进行了对比。研究表明：《建筑抗震设计规范》（GB 50011—2016）和《建筑结构抗倒塌设计标准》（T/CECS 392—2021）的选波规定对结构弹性时程分析有较好的预估；对结构弹塑性反应，《建筑抗震韧性评价标准》（GB/T 38591—2020）表现出与目标反应较好的一致性；《建筑结构抗倒塌设计标准》（T/CECS 392—2021）考虑了与目标谱的分段周期匹配选波，在考虑弹塑性反应周期延长方面有所不足，存在低估结构反应的可能。

Abstract:

Time history analysis has been used as the main method for assessing the seismic response of structures in the code. The input ground motion records are an important factor affecting the results of the time history analysis. The records input provisions involved in the building related seismic codes are summarized. With the help of the weighted scaling method et al, we take 15-storey and 30-storey reinforced concrete high-rise structures as examples, and the results of the elastic and elasto-plastic time response of the structure are compared with the seismic responses from the records selected according to the codes and methods. In the research we use the maximum inter-story drift ratios as the target response. The results show that the records selection provisions of Code for Sesimic Design of Buildings（GB 50011—2016）and Standard for Anti-collapse Design of Building Structures (T/CECS 392—2021) provide a good prediction of the elastic response values by time-history method. For the elastic-plastic time-history analysis the response based Standard for Seismic Resilience Assessment of Buildings (GB/T 38591—2020) shows better consistency with the target response. The recommended record selection for Standard for Anti-collapse Design of Building Structures (T/CECS 392—2021), which considers the segment period matching with the target spectrum, which is inadequate in considering the length of the structural periods during elasto-plastic response. There is a possibility of underestimating the structural response.