The Effects of Topographical and Geotechnical Characteristics of Sites on Seismic Movements Due to Natural and Human-Induced Earthquakes

地震发生在加拿大大部分地区，其影响可能会受到场地效应的很大影响。场地效应是由于局部地形和地质特征而引起的地震地面运动的修正。它们可能是许多人口稠密地区的主要担忧，因为这些场地效应可能以意想不到的方式导致城市基础设施的不稳定。人们经常观察到，地震过后，一些位于山丘上或沉积盆地中的建筑遭受的破坏比它们距离震中的预期要大得多。例如，在1946年温哥华岛7.2级地震期间，阿尔伯尼港大多数受损的烟囱都建在厚厚的松软土壤上。建在岩石上的房屋几乎没有受损。 除了自然发生的地震外，近年来人为引发的地震急剧增加。人类诱发的地震是由人类活动引起的，如致密页岩地层的水力压裂和水库蓄水。人类引发的地震可能与自然地震一样具有破坏性。在这方面的众多例子中，我们可以突出2008年中国在紫坪铺大坝附近发生的四川省7.9级大地震，造成69,000人死亡，另有18,000人失踪。这次地震是由水库蓄水引起的。 必须考虑岩土灾害，以确保公共安全。这意味着评估与工业地下作业相关的注入引起的地质断层和地震事件重新激活的可能性。然而，这也需要研究当地的地形和地质特征(场地影响)，以确定它们将如何影响基础设施对地震运动的反应。 这项研究计划将专注于开发能够模拟土壤动态行为的新的数值工具。这项研究有许多实际应用，包括研究自然和人为地震引起的斜坡破坏，为地震危险性和风险评估提供信息，以及对土石坝进行地震分析。此外，这项工作将有助于改善我们目前对工业地下活动引起的人类诱发地震的认识不足。 对加拿大来说，潜在的经济效益是巨大的。据估计，温哥华等主要中心附近的大地震可能会造成约700亿美元的经济损失。 在本次研究期间，两名博士生和两名硕士研究生将在我的直接指导下接受培训。通过我的指导，这些研究生将在岩土工程的多孔力学和数值模拟领域获得宝贵的经验，这将是加拿大工程公司的一笔可观的财富。

Earthquakes occur in most parts of Canada, and their impact can be greatly influenced by site effects. Site effects are modifications of seismic ground movement due to local topography and geological characteristics. They can be a major concern for many populated areas, because of the potential of these site effects to contribute in unexpected ways to the destabilization of urban infrastructure. It has often been observed that, after earthquakes, some buildings located on hills or in sedimentary basins suffer greater damage than would be expected from their distances to the epicenter. For example, during the magnitude 7.2 Vancouver Island Earthquake in 1946, most of the damaged chimneys in Port Alberni were in areas built on thick soft soils. Houses built on rock exhibited little damage. In addition to naturally occurring earthquakes, recent years have seen dramatic increases in human-induced earthquakes. Human-induced earthquakes are those caused by human activities like hydraulic fracturing in tight shale formations and impoundment of reservoirs. Human-induced earthquakes can be just as devastating as natural ones. Among the many examples in this regard, we can highlight the large magnitude 7.9 China’s Sichuan Province earthquake near Zipingpu Dam in 2008, killing 69,000 people and leaving another 18,000 missing. This earthquake resulted from the reservoir impoundment. Geotechnical hazards must be considered to ensure public safety. This means assessing the potential for injection-induced reactivation of geological faults and seismic events associated with industrial underground operations. However, it also requires study of local topographical and geological characteristics (site effects) to determine how they will affect the response of infrastructure to seismic movements. This research program will focus on the development of new numerical tools that can model the dynamic behavior of soils. There are many practical applications of this research, including studies of slope failures caused by natural- and human-induced earthquakes, providing information for seismic hazard and risk assessments, and seismic analyses of embankment dams. In addition, this work will help to improve our current poor understanding of human-induced earthquakes caused by industrial underground activities. The potential economic benefits for Canada are significant. It has been estimated that large earthquakes near major centers like Vancouver, could result in economic losses from earthquake-induced damages that are on the order of seventy billion dollars. During this research program, two PhD students and two MSc students will be trained under my direct supervision. Through my guidance, these graduate students will gain valuable experience in the areas of porous mechanics and numerical modeling in geotechnical engineering that will be a considerable asset to Canadian engineering companies.