Characterization of the mechanical response of fine-grained soils for earthquake engineering practice

地震工程实践中细粒土的力学响应表征

• 批准号: RGPIN-2017-03846
• 负责人: Wijewickreme, Dharmapriya
• 金额: $ 2.48万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=710583
• 关键词: Characterization; mechanical; response; fine; grained

Liquefaction of soil has caused severe damage to structures and lifelines during past earthquakes, and has led to loss of life and disruptions to living and working conditions of citizens. The Metro Vancouver Region of British Columbia (BC) is located in a zone of high seismicity, and it has been reported that the damage costs from a major earthquake in Vancouver could be as high as $75 billion. Saturated fine-grained soils (e.g., silts) are commonly found in natural river deposits and also originate as a waste product in tailings derived from the mining industry. Recent earthquake experience suggests that liquefaction of natural silts is a concern; it is also known that densification of silt to mitigate liquefaction is more expensive than the methods required for sands. Much of the current research focus has been on the liquefaction of sands whereas the seismic behaviour of low-plastic fine-grained silts has been investigated only on a limited scale. There is strong evidence that silt behavior is complex and not well understood, and there is a need to develop robust approaches for silt liquefaction assessment for safe and cost-effective designs. This requires advancing the knowledge on the mechanics of silts under seismic shaking and investigating the effects of the key physical factors on the behaviour of silts. With this impetus, systematic experimental research will be undertaken to study the fine-grained soils through the following focused themes: (i) Cyclic shear response of sand-silt and silt-clay Mixtures; (ii) Effect of vibro-replacement on the response of silts; and (iii) Particle structure of silts. The research will generate a comprehensive database for silt behaviour useful for improving the numerical models predicting earthquake-induced geotechnical hazards. The work will develop practice guidelines with robust approaches to assess liquefaction of silts, advance the laboratory technology for testing of silts, and develop new methods for assessing the effectiveness of the measures taken to improve silts against liquefaction. The use of modern imaging technologies to study the particle structure of silts will provide new insight to supplement the conventional seismic design approaches in a novel way. The results will be of global significance to geotechnical design in earthquake-prone silt-soil areas, and especially with respect to enhancing the seismic safety of Canadians. With the knowledge gaps bridged, the work will contribute to developing novel methods with particular applicability to civil and mining engineering. Three masters and four doctoral students will be trained, thus adding to the earthquake engineering expertise in Canada. With the high quality of training received, the students entering the workforce will possess a high employability.

在过去的地震中，土壤液化对建筑物和生命线造成了严重破坏，并导致了生命损失和公民生活和工作条件的破坏。不列颠哥伦比亚省（BC）的大都会温哥华地区位于高地震活动区，据报道，温哥华发生大地震的损失可能高达750亿美元。饱和细粒土（例如，淤泥）通常存在于天然河流沉积物中，并且也作为来自采矿业的尾矿中的废物产生。 最近的地震经验表明，天然粉土的液化是一个问题;人们也知道，压实粉土以减轻液化比砂所需的方法更昂贵。目前的研究重点主要集中在砂土的液化上，而对低塑性细粒粉土的地震特性仅在有限的范围内进行了研究。 有强有力的证据表明，粉土的行为是复杂的，并没有得到很好的理解，有必要开发强大的方法进行粉土液化评估的安全和成本效益的设计。 这就需要提高对地震震动下粉土力学的认识，并调查关键物理因素对粉土行为的影响。 在此推动下，将进行系统的试验研究，以研究细粒土通过以下重点主题：（i）砂粉土和粉土粘土混合物的循环剪切响应;（ii）振动置换对粉土响应的影响;和（iii）粉土的颗粒结构。 这项研究将产生一个关于淤泥特性的综合数据库，有助于改进预测地震引起的岩土灾害的数值模型。 这项工作将制定实践指南，采用强有力的方法来评估淤泥的液化，推进淤泥测试的实验室技术，并制定新的方法来评估为改善淤泥液化而采取的措施的有效性。利用现代成像技术研究粉土的颗粒结构，将为传统的抗震设计方法提供新的补充。研究结果将对地震多发的粉土地区的岩土工程设计具有全球意义，特别是对提高加拿大人的地震安全性具有重要意义。 随着知识差距的弥合，这项工作将有助于开发特别适用于土木和采矿工程的新方法。 将培养3名硕士生和4名博士生，从而增加加拿大的地震工程专业知识。由于接受了高质量的培训，进入劳动力市场的学生将具有很高的就业能力。