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由于新规定要求危险性估计必须使用概率术语,进行概率危险性研究的数量最近一直在增加。本研究旨在确定根据这些研究和观测进行比较预测的可能性和范围。直接根据地面运动发生率的比较检验比地震发生率更受青睐。根据泊松过程的特性,计算和评估了能确保场点发生率估计可靠的最小时间窗。例如,对于场点复发期为475年的地面运动,要求用来估计地面运动发生率的最小观测时间窗为12000年,且不确定性为20%(变异系数:标准差除以平均值)。这些值不取决于所研究地区的地震活动性水平。对法国固定加速度计台网台站记录的地面运动进行的分析表明,对于很低的加速度水平(STET台站0.0001～0.001g),地面运动发生率估计的最高精确度为30%。在有更长记录历史和位于更高地震活动区(希腊和加利福尼亚州)的2个台站进行的同样分析,提供了可达0.1g的地面运动水平。因此,提出的问题是,即使使用的是对于广泛范围的加速度都一致有效的地面运动预测公式,基于低加速度水平的比较检验所得出的结果能推广到更高的加速度水平吗?
As the new rules require the use of probability terms to require a risk assessment, the number of probabilistic hazard studies has been increasing lately. The purpose of this study is to determine the likelihood and scope of comparative predictions based on these studies and observations. Directly based on the comparison of the incidence of ground motions than the incidence of earthquakes more favored. According to the characteristics of Poisson process, the minimum time window that can ensure the reliable estimation of site incidence is calculated and evaluated. For example, for a ground motion of 475 years of field recurrence, the minimum observation time window required to estimate the incidence of ground motion is 12,000 years and the uncertainty is 20% (coefficient of variation: standard deviation divided by average). These values do not depend on the level of seismicity in the area under study. An analysis of the ground motion recorded by the French Stationary Station of Stationary Accelerometers shows that for the very low level of acceleration (0.0001-0.001 g for STET stations), the highest accuracy of ground motion estimates is 30%. The same analysis conducted at two stations with longer recording history and at higher seismic zones (Greece and California) provided ground level up to 0.1g. Therefore, the question raised is whether the results of a comparison test based on low acceleration levels can be generalized to higher acceleration levels, even if the formula for predicting ground motion is consistent and effective for a wide range of accelerations?