Innovative lateral load resisting systems for mid-rise timber frame buildings

自2009年以来，加拿大各省和联邦司法管辖区修改了各自的建筑法规，将住宅木结构建筑的层数限制从4层增加到6层。随着高度的增加，对用于建造中高层（最高6层）木框架建筑的更强的剪力墙系统的需求也随之增加，与低层（最高4层）建筑相比，中高层木框架建筑通常需要更高的抗重力和横向荷载能力。与强木框架剪力墙相关的研究有限。简单地加强传统剪力墙的抵抗力可能会损害其他结构性能，例如延性和耗能能力，这是影响结构在地震荷载下的性能的两个关键特性。在这项研究计划中，主要目的是开发一种更强大的剪力墙系统，可用于建造中高层木框架建筑，具有可比的延性和耗能能力，传统的墙壁。 在拟议的研究中，新开发的墙系统的高侧阻力将通过重新安排传统剪力墙中使用的三个主要组件来实现：尺寸木材，护板和钉子。多排钉子将沿着覆板边缘对齐，因为这些钉子接头预计将控制墙系统的失效模式和侧向阻力。同时，木框架将通过使用多个板和栓钉来加强，以避免框架构件的失效。这些增强板和立柱也可以放置在90度旋转，尺寸木材的较宽面钉在覆板上，这类似于中层剪力墙系统。在这种情况下，使用多剪切和多排护套到框架钉。需要一个强大的压紧系统来防止上举失败。 在本研究计画中，将借由实验研究与数值模拟分析来探讨新开发剪力墙系统之结构性能。两名硕士生在1-2年将调查的性能连接用于强剪力墙。在第一阶段结束时，将获得各种配置的连接的失效模式和力学性能。两名博士生将在第二阶段继续系统层面的研究。其中一名博士生将专注于剪力墙设计细节的优化。另一名博士生将专注于地震荷载下木材和木基混合建筑的结构性能。在本研究的最后，它是期望更好地了解新开发的剪力墙系统的结构性能将实现在三个层次上：节点，墙系统和整个建筑。

Since 2009, various provincial and federal jurisdictions in Canada have amended their respective building codes to increase the storey limit of residential wood frame buildings from 4 to 6 storeys. Increases in height have raised the demand for a stronger shear wall system for construction of mid-rise (up to 6 storey) timber frame buildings that usually require higher resistance against gravity and lateral loads than low-rise (up to 4 storey) buildings. Research related to strong wood frame shear walls is limited. Simply reinforcing the resistance of the traditional shear wall may compromise other structural properties, such as ductility and energy dissipation capacity, which are two of the key characteristics affecting the performance of structures under earthquake loads. In this research program, the main aim is to develop a stronger shear wall system that can be used in construction of mid-rise timber frame buildings that has comparable ductility and energy dissipation capacity to traditional walls. In the proposed research, the high lateral resistance of the newly developed wall system will be achieved by re-arranging the three main components used in traditional shear walls: dimension lumber, sheathing panels and nails. Multi-rows of nails will be aligned along the edges of sheathing panels as these nail joints are expected to control the failure mode and lateral resistance of the wall system. Meanwhile, the timber frame will be enhanced by using multiple plates and studs to avoid failure at the frame members. These enhanced plates and studs can also be placed at a 90 rotation with the wider face of dimension lumber nailed to the sheathing panels, which is similar to a midply shear wall system. In this case, multi-shear and multi-row sheathing-to-framing nails are used. A strong hold-down system is required to prevent up-lift failure. In this research program, the structural performance of the newly developed shear wall system will be investigated through both experimental study and numerical modeling analysis. Two master students in years 1-2 will investigate the performance of connections used in the strong shear walls. At the end of phase 1, the failure mode and mechanical properties of connections with various configurations will be obtained. Two PhD students will continue the research at the system level in phase 2. One of the PhD students will focus on the optimization of design details of shear walls. The other PhD student will focus on the structural performance of timber and timber-based hybrid buildings under seismic load. At the end of this research, it is expected that a better understanding of the structural performance of the newly developed shear wall system will be achieved on three levels: joints, wall systems and the whole building.