Seismic design and evaluation of high-rise concrete shear wall buildings in Canada

这项研究计划的长期目标是减少在加拿大高层建筑中生活和工作的人的危险。温哥华大都会最终将经历一场大地震，它的高层建筑比西雅图西雅图和波特兰或奥克兰的总和还要多。其中许多剪力墙建筑是在加拿大建筑规范采用现代抗震设计要求之前建造的。*这项研究涉及开发工程师评估现有建筑的抗震安全性和设计新建筑所需的方法。该研究项目涉及多个相关项目。这一长期研究计划之前的许多项目已经导致加拿大建筑规范和HQP的重大变化，从事这类抗震评估和设计的工程公司对HQP的需求很高。*未来五年，这些项目将包括：*旧的混凝土薄墙建筑的抗震安全性。这类建筑对加拿大的地震危害有很大贡献，因为它们很普遍，入住率很高，而且很可能在地震中表现不佳。与美国的建筑不同，加拿大的许多旧建筑都有薄薄的混凝土墙作为地震力抵抗系统和重力荷载抵抗系统。将完成两个项目-一个使用考虑典型不对称布置的非线性动力分析来研究建筑物的全球响应，第二个使用非线性有限元分析来研究不连续性的影响。*开发一个合理的混凝土墙在地震荷载下的抗剪模型。在评估现有建筑或设计新建筑时，工程师面临的最大挑战之一是为承受地震荷载的混凝土墙提供足够的抗剪能力。目前的方法是从施加了数小时重力载荷的试验中发展而来的。新的实验室试验将在模拟剪力墙上进行，以确定混凝土墙在地震荷载下的抗剪能力。这些墙将受到复杂的第一振型位移模式和复杂的高振型剪力模式，这些模式是由建筑物的非线性分析确定的。抗剪强度将取决于需求的计算方式，例如，地震期间的单个最大剪力脉冲。*剪力墙建筑地基的评估。新建筑中的剪力墙通常在到达地基之前延伸到低于地面的许多楼层，而较老的建筑通常有直接支撑在浅基础上的剪力墙。将进行研究，以完善非线性基础旋转的预测和高度不确定体系中的力分布，当剪力墙延伸通过许多低于路基的横隔板时。

The long-term objective of this research program is to reduce the hazard for people living and working in high-rise buildings in Canada. Metro Vancouver, which will eventually experience a large earthquake, has more high-rise buildings than Seattle WA and Portland OR combined. Many of these shear wall buildings were built prior to modern seismic design requirements being adopted in Canadian building codes.***The research involves development of the methods engineers need to evaluate the seismic safety of existing buildings and design new buildings. The research program involves a number of related projects. Many previous projects from this long-term research program have resulted in significant changes to the Canadian building codes and the HQP that have been involved are in high demand by engineering companies that do this type of seismic evaluation and design.****Over the next five years, the projects will include:****Seismic safety of older existing buildings with thin concrete walls. Such buildings contribute significantly to the seismic hazard in Canada because of their prevalence, high occupancy and the likelihood that they will not perform well in an earthquake. Unlike buildings in the US, many of the older buildings in Canada have thin concrete walls as the seismic-force resisting system and the gravity-load resisting system. Two projects will be done - one looking at the global response of buildings using nonlinear dynamic analysis accounting for the typical non-symmetrical arrangement of walls, and a second looking at the influence of discontinuities using nonlinear finite element analysis.****Development of a rational model for the shear resistance of concrete walls subjected to earthquake loading. One of the greatest challenges engineers face when evaluating existing buildings or designing new buildings is providing sufficient shear resistance of concrete walls subjected to earthquake loading. The current methods were developed from tests with gravity loads applied for many hours. New laboratory tests will be conducted on simulated shear walls to determine the shear resistance of concrete walls subjected to earthquake loading. The walls will be subjected to a complex pattern of first mode displacements and a complex pattern of higher mode shear forces determined from nonlinear analyses of buildings. The shear resistance will depend on how the demand is calculated, e.g., single maximum shear force pulse during an earthquake.****Evaluation of shear wall building foundations. Shear walls in new buildings often extend through many levels below grade before reaching the foundation, while older buildings often have shear walls supported directly on shallow footings. Research will be done to refine the prediction of nonlinear foundation rotations and the force distribution in the highly indeterminate system when shear walls extend through numerous below-grade diaphragms.**