大跨度斜拉桥地震易损性及可恢复性分析

为了研究地震作用下斜拉桥主塔的抗震能力，评估其抗震可恢复性，以一座独柱式大跨径混凝土斜拉桥为例，采用SAP2000有限元分析程序建立结构动力计算模型，通过增量动力分析法（IDA）分析结构的横向地震响应；选用X-TRACT软件对主塔划分的各关键截面进行了弯矩-曲率分析和损伤标定，对IDA分析的数据进行处理，拟合得到了主塔各关键截面的地震易损性曲线，确定主塔容易损伤部位及演变规律；基于可恢复性的理念开展结构的抗震可恢复性分析. 研究结果表明:在横向地震作用下，主塔底部截面是所选截面中最容易损坏的部位；在地震动强度0.150g和0.271g作用后，自身的抗震能力由80.6%降到46.7%，随着地震动强度的增大，抗震储备能力不断降低. 

Analysis of Seismic Fragility and Recoverability of Long-Span Cable-Stayed Bridge

To study the seismic capacity of the main tower of cable-stayed bridge under earthquake and evaluate its seismic recoverability, the structural dynamic calculation model was established by the finite element analysis program SPA2000 based on a single-column long-span concrete cable-stayed bridge, the seismic response of the transverse cable-stayed bridge was analyzed by incremental dynamic analysis (IDA). The moment-curvature curves of the tower key sections were studied and the curvature damages were calibrated by analysis software X-TRACT, then the data from IDA analysis were processed, and the seismic vulnerability curve of each key sections of the main tower was obtained, and the vulnerable part of the main tower and its evolution law were determined. Based on the concept of recoverability, the seismic restorability analysis of the structure was carried out. The results show that under the action of transverse seismic, the bottom section of the tower is the vulnerable section. When the action of seismic intensities are 0.150g and 0.271g, its own seismic capacity decrease from 80.6% to 46.7%, with the increase of seismic intensity, the bridge’s seismic reserve capacity decrease.