Soil and Foundation Improvement Solutions for Seismic Resistant Design

修订后的国家建筑规范(NBCC 2005)中包含的升级的地震荷载假定加拿大的地震危险性增加。大多数现有结构，包括主要基础设施(如核电站、桥梁等)，都是在这些新的设计准则之前设计和建造的，仍然容易受到地震破坏。此外，在最近的地震中，由于基础过度沉降和/或旋转而导致的建筑物倒塌，突显了设计能够承受作用在支撑结构上的地震力的基础的重要性。因此，有必要准确地描述关键基础设施系统的地震风险，并为新结构和现有结构的抗震基础提供创新的解决方案。*这里提出的研究计划旨在开发创新技术，以提高现有基础的横向承载能力，并开发构建抗震基础系统的新技术。这项研究的具体目标是：a)评估地震场地反应和土-结构相互作用(SSI)对软土中基础输入运动的影响；b)探索适合于抵抗地震荷载的有效基础体系；c)开发现有结构基础的创新加固技术。本研究将采用实验和数值分析相结合的方法。通过振动台试验研究场地地震反应、土-结构相互作用以及纤维增强聚合物桩的动力响应。此外，亦会进行桩柱荷载测试，以检验现有及新的基础设施系统的不同加筋桩基系统的轴向及横向承载能力。*这项研究预计将为抗震设计提供土壤和基础改善解决方案，并为加固现有不充分的基础制定设计指南。许多基础设施项目、石化工厂、桥梁和可再生能源项目将受益于这项研究的结果。改善我们的基础设施的地震安全和降低地震风险，将为我们的社会带来重大的社会和经济利益。这项研究还有望使加拿大公众受益，并由于更安全和耐用的设计而保护环境。

The upgraded seismic loading included in the revised national building code (NBCC 2005) postulates an increased seismic hazard in Canada. Most existing structures, including major infrastructure (e.g. nuclear power plants, bridges, etc.), were designed and constructed prior to these new design guidelines and are still susceptible to earthquake damage. In addition, failures of buildings during recent earthquakes due to excessive settlement and/or rotation of foundations have highlighted the importance of designing foundations that can withstand the seismic forces acting on the supported structure. Therefore, there is a need to accurately characterize the seismic risk for critical infrastructure systems and to provide innovative solutions for seismic resistant foundations for new and existing structures. ******The research program proposed here aims at developing innovative techniques for enhancing the lateral load capacity of existing foundations and developing new techniques for constructing earthquake-resistant foundation systems. The specific objectives of this research are: a) to evaluate the seismic site response and soil-structure interaction (SSI) effects on foundation input motion in soft soils; b) explore efficient foundation systems suitable for resisting seismic loads, and c) develop innovative retrofitting techniques for foundations of existing structures. Both experimental and numerical analyses will be employed to conduct this research. Shaking table tests will be conducted to study seismic site response and soil-structure interaction, as well as dynamic response of Fiber Reinforced Polymer piles. Pile load tests will also be used to examine the axial and lateral capacity of different reinforced pile foundation systems for existing and new infrastructure systems. ******The research is anticipated to provide soil and foundation improvement solutions for seismic resistant design and produce design guidelines for retrofitting of existing inadequate foundations. Many infrastructure projects, petrochemical plants, bridges, and renewable energy projects will benefit from the findings of this study. The improved seismic safety and reduced seismic risk in our infrastructure will provide significant social and economic benefits to our community. This research is also expected to benefit the Canadian public and protect the environment as a result of safer and resistant designs.