Soil and Foundation Improvement Solutions for Seismic Hazards

修订后的国家建筑规范（NBCC 2005）中包含的升级地震荷载假定加拿大的地震危险增加。大多数现有结构，包括主要基础设施（如核电厂、桥梁等），在这些新的设计准则之前设计和建造，容易受到地震破坏。因此，需要为新的和现有的结构提供抗震基础的创新解决方案。该研究计划代表了通过开发现有结构基础的创新改造技术以及开发建造抗震基础系统的新技术来进行抗震设计的努力。 以往的地震已经清楚地强调了当地场地条件和土-结构相互作用（SSI）对地震破坏的作用。本研究调查了城市地区的场地反应和SSI，并探索了土壤改良解决方案，以减轻结构底部的地面运动。考虑到日益需要修订基础设施的防灾措施以及现有备选方案的缺点，拟议的研究还试图调查两种创新技术，使用土工泡沫和板桩来改造现有基础设施的基础，以保护它们免受地震破坏。地震期间基础摇摆对其响应有很大影响，并且可能涉及一端的抬升和另一端的屈服。采用桩荷载试验和数值模拟方法研究了纤维增强聚合物复合地基的抗震设计。该研究预计将提供土壤和地基改良技术，有效的基础系统和设计指南，用于改造现有的不充分的基础以及新的抗震基础。这些技术在建筑业和运输业中需求量很大。

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 susceptible to earthquake damage. Thus there is a need to provide innovative solutions for earthquake resistant foundations for new and existing structures. This research program represents an effort towards resistant seismic design through developing innovative retrofitting techniques for foundations of existing structures as well as developing new techniques for constructing earthquake-resistant foundation systems. Previous earthquakes have clearly highlighted the role of local site conditions and soil-structure interaction (SSI) on earthquake damage. This research investigates the site response and SSI in urban areas and explores a soil improvement solution to mitigate the ground motion at the base of a structure. Considering the growing need for revision of hazard prevention measures for infrastructure facilities and disadvantages of available options, the proposed research also seeks to investigate two innovative techniques using geofoam and sheet piles to retrofit the foundations of existing infrastructures in order to protect them from earthquake damage. Foundation rocking during an earthquake contributes significantly to its response and may involve both uplift at one end and yield at the other. A composite mircopile foundation system, reinforced with fibre reinforced polymer, will be investigated using pile-load tests and numerical modelling for seismic resistant design. The research is expected to provide soil and foundation improvement techniques, efficient foundation systems and design guidelines for retrofitting of existing inadequate foundations as well as new seismic resistant foundations. These techniques are in high demand in the construction industry and transportation.