There is a need for benchmarking and validating simulated ground motions in order for them to be utilized by the engineering community. Such validation may be geared towards a specific ground motion simulation method, a target engineering application, and a specific location; the validation presented herein focuses on a bridge engineering application in southern California. Catalogs of simulated ground motions representing a 200,000-year forecast are selected from the Southern California Earthquake Center CyberShake version 15.12 database for five sites in Southern California (~20,000 unscaled ground motions per site). They are used in Non-Linear Time History Analysis (NLTHA) of four Ordinary Standard Bridge structures. For each site, these data are used to obtain simulation-based Engineering Demand Parameter (EDP) hazard curves. These are compared against EDP hazard curves that are constructed using conventional methods based on empirical models, i.e., using recorded ground motions through Incremental Dynamic Analysis and integration over the Intensity Measure (IM) hazard curve. The two sets of simulation-based and conventional EDP hazard curves are compared at various return periods. To further account for the differences between simulated and recorded ground motions, direct comparisons are also made between IM hazard curves for simulated and recorded catalogs, as well as the EDP versus IM data obtained from NLTHA of the bridges. We observe that CyberShake simulates motions that yield similar EDP values compared to empirical data for shorter return periods. For longer return periods, however, EDPs from the simulation-based analysis tend to be lower than the EDPs obtained from utilizing recorded ground motions for short-period bridges, while the opposite is the case for long-period bridges. It is recommended that validation efforts go beyond IM levels and also include comparisons of the relations between IMs and EDPs. Finally, site-specific relations are proposed that correlate the ratio between the two types of EDPs (simulation-based and conventional) with the hazard level, shallow site condition, and site basin depth.

需要对基准地面运动进行基准测试和验证，以便工程界可以利用它们。这样的验证可以针对特定的地面运动模拟方法，目标工程应用和特定位置。本文提供的验证重点是在加利福尼亚南部的桥梁工程应用中。从南加州地震中心Cyber​​Shake版本15.12数据库中选择了代表20万年预测的模拟地面运动的目录，该数据库用于南加州的五个站点（每个站点约20,000个未缩放的地面运动）。它们用于四个普通标准桥梁结构的非线性时程分析（NLTHA）。对于每个站点，这些数据都用于获取基于仿真的工程需求参数（EDP）危险曲线。将这些与EDP危害曲线进行比较，EDP危害曲线是使用基于经验模型的常规方法构造的，即使用通过增量动态分析记录的地面运动并整合强度测度（IM）危害曲线。比较了两组基于仿真的EDP危险曲线和常规EDP危险曲线在不同的返回时间段。为了进一步说明模拟和记录的地震动之间的差异，还对模拟和记录的目录的IM危险曲线以及从桥梁的NLTHA获得的EDP与IM数据之间进行了直接比较。我们观察到，Cyber​​Shake模拟的运动与较短时间的返回数据相比，与经验数据相比产生的EDP值相似。但是，对于更长的退货期限，基于仿真的分析得出的EDP往往低于通过对短周期桥梁使用记录的地面运动获得的EDP，而对于长周期桥梁则相反。建议验证工作超出IM级别，并且还应包括比较IM和EDP之间的关系。最后，提出了特定地点的关系，该关系将两种类型的EDP（基于模拟的和常规的）EDP的比率与危害水平，浅层场地条件和立场盆地深度相关联。