基于云图-条带法的概率地震需求分析与地震易损性分析

PROBABILISTIC SEISMIC DEMAND ANALYSIS AND SEISMIC FRAGILITY ANALYSIS BASED ON A CLOUD-STRIPE METHOD

提出一种概率地震需求分析的云图-条带法。该方法通过引入经验地震易损性分析中的数据处理方法,解决传统云图法无法处理海量非线性时程分析结果的局限。为说明该文提出方法,选取100条地震动作为输入,针对23个钢筋混凝土框架结构进行了云图法分析。基于所有结构的云图结果,采用云图-条带法建立了群体结构的概率地震需求模型,并计算得到了群体结构的地震易损性。研究表明:云图-条带法可以有效地处理海量非线性时程分析结果,建立较为合理的概率地震需求模型。在输入地震动的强度范围内,群体结构整体发生严重破坏和完全破坏的概率很低,而主要以发生轻微破坏和中等破坏为主。

A cloud-stripe method is presented for probabilistic seismic demand analysis. This method adopts the strategy commonly used in empirical seismic fragility analysis in order to overcome the limitations of the conventional cloud method in dealing with large amounts of nonlinear time-history data. To illustrate the presented method, 100 real ground motion records are selected as inputs. A total of 23 RC frame structures are used as study cases to perform analyses using the cloud method. Based on the cloud results of all the structures, the probabilistic seismic demand model for the group buildings is derived using the cloud-stripe method, and the corresponding fragility results are calculated. Results show that the cloud-stripe method can effectively handle a large amount of nonlinear time-history analysis data and can develop a reasonable probabilistic seismic demand model. Conditioned on the intensity scope of the considered ground motion records, the group buildings have a limited possibility of occurring severe or complete damage, while their damage outcomes are dominated by slight and moderate damage.