Ground Motion Prediction Using Virtual Earthquakes

使用虚拟地震进行地面运动预测

• 批准号: 1520867
• 负责人: Gregory Beroza
• 金额: $ 29.5万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-15 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1520867&HistoricalAwards=false
• 关键词: Ground; Motion; Prediction; Using; Virtual

This research is motivated by the fact that there exist few quantitative measurements of the strength of shaking close to the epicenters of large earthquakes. Information on how strong the ground will shake is critically important because structural engineers use this information to design earthquake-resilient structures. We will further develop and apply a new approach for predicting the strength of shaking in future earthquakes that doesn?t rely on recording earthquakes directly, but uses the ambient seismic field for that purpose. The ambient field consists of seismic waves in the solid Earth that are generated by wave action in the ocean. We can use these to develop ?virtual earthquakes? using ground motion sensors deployed at a location on the Earth where we expect future earthquake rupture to occur. Virtual earthquakes quantify the shaking that will occur when such an earthquake happens. Specifically, our research will advance this method by improving the calibration of the strength of shaking, applying it to areas of particular concern where we expect the shaking to be strong and potential problematic for buildings, and by extending the technique to shorter periods, which are important for earthquake-resistant design.Ground motion prediction is an area of key importance for earthquake seismology as it is where the multi-disciplinary endeavor of understanding earthquake behavior meets the societal concern of mitigating earthquake losses. We propose to improve and apply a new method for predicting spatial variations in ground motion using the ambient seismic field to construct virtual earthquakes. The virtual earthquake approach is possible because the waves that comprise the ambient field, and the waves in large earthquakes, propagate through the same complex geologic structure and are affected by it in the same way. While this approach does not account for nonlinear effects, and does not address earthquake source characterization, it does provide a genuinely new way to predict the complex linear wave propagation effects that strongly influence the intensity of earthquake shaking. The proposed research seeks to improve the accuracy and applicability of the virtual earthquake approach by: (1) improving the reliability of measured amplitudes, (2) exploring complex basin effects that have not been incorporated into ground motion prediction equations, and (3) pushing the technique to shorter periods that better overlap the period range of primary earthquake engineering concern. Continued development of the virtual earthquake approach for ground motion prediction is essential for it to realize its full potential. We will continue our collaboration with scientists at
the Earthquake Research Institute at the University of Tokyo and at ISTerre, Grenoble. We will also work to develop an emerging collaboration with scientists and engineers at Universidad Nacional Autonoma de Mexico, in Mexico City.

这项研究的动机是，对大地震震中附近的震动强度几乎没有定量测量。 有关地面震动强度的信息至关重要，因为结构工程师利用这些信息来设计抗震结构。 我们将进一步开发和应用一种新方法来预测未来地震中的震动强度，该方法不依赖于直接记录地震，而是使用周围地震场来实现这一目的。 环境场由固体地球中的地震波组成，这些地震波是由海洋中的波浪作用产生的。 我们可以用它们来开发“虚拟地震”？使用部署在地球上我们预计未来会发生地震破裂的位置的地面运动传感器。 虚拟地震量化了此类地震发生时将发生的震动。 具体来说，我们的研究将通过改进震动强度的校准来推进该方法，将其应用于我们预计震动强烈且对建筑物存在潜在问题的特别关注的区域，并将该技术扩展到更短的时期，即对于抗震设计很重要。地震动预测是地震学的一个非常重要的领域，因为它是理解地震行为的多学科努力满足社会对减轻地震损失的关注的地方。 我们建议改进并应用一种新方法，利用周围地震场来预测地震动的空间变化，以构建虚拟地震。虚拟地震方法是可能的，因为构成环境场的波和大地震中的波通过相同的复杂地质结构传播并以相同的方式受到其影响。虽然这种方法没有考虑非线性效应，也没有解决震源特征，但它确实提供了一种真正的新方法来预测强烈影响地震震动强度的复杂线性波传播效应。 该研究旨在通过以下方式提高虚拟地震方法的准确性和适用性：（1）提高测量振幅的可靠性，（2）探索尚未纳入地震动预测方程的复杂盆地效应，以及（3）推动该技术可以缩短周期，更好地与主要地震工程关注的周期范围重叠。持续开发用于地震动预测的虚拟地震方法对于充分发挥其潜力至关重要。我们将继续与东京大学地震研究所和格勒诺布尔 ISterre 的科学家合作。 我们还将努力与墨西哥城墨西哥国立自治大学的科学家和工程师开展新兴合作。