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，容易受到地震破坏。因此，有必要为新建和既有结构的抗震基础提供创新的解决方案。这项研究计划代表了通过开发对现有结构基础的创新改造技术以及开发构建抗震基础系统的新技术来进行抗震设计的努力。以前的地震清楚地突出了当地场地条件和土-结构相互作用(SSI)在地震破坏中的作用。本研究调查城市地区的场地反应和SSI，并探索一种土壤改良解决方案，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灾害预防措施和现有选择的缺点，拟议的研究还试图调查两种创新技术，使用地质泡沫和板桩来翻新现有基础设施的基础，以防止它们受到地震破坏。地震过程中的基础摇摆对其响应有很大影响，可能一端发生隆起，另一端发生屈服。采用桩荷载试验和抗震设计的数值模拟方法，对纤维增强聚合物复合地基体系进行了研究。预计这项研究将提供土壤和基础改进技术、有效的基础系统和设计指南，用于翻新现有的不充分基础以及新的抗震基础。这些技术在建筑业和运输业中的需求量很大。

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.