Behaviour and design of concrete masonry infill walls

在现代建筑结构中，砌体填充墙通常用作钢框架和钢筋混凝土框架中的内隔墙以及外墙填充物。由于缺乏科学的信息，在量化的填充物和框架之间的复合作用的程度，在工业中应用的常见的设计实践一直是处理砌体填充墙作为非结构元件和设计框架的重力和横向载荷。砌体填充墙对框架刚度和强度的贡献因此被忽略。然而，忽略填充墙的贡献是一种保守的方法，这是一种误解。填充墙显著地破坏了框架，从而降低了其延性，这反过来又吸引了更大的力到结构中的填充区域。 设计不良的填充墙已被确定为地震中灾难性结构失效的一个促成因素。虽然目前的加拿大砌体设计标准CSA S304提供了考虑填充刚度和强度的方程，使用这些方程获得的值被发现是在与从实验测试中获得的由不同的研究人员进行，也与其他公认的代码，如新西兰砌体代码NZS 4230和欧洲规范8获得的值不一致。为了将砌体填充物纳入结构抗侧力和抗重力体系的设计中，合理准确地评估其刚度和强度是至关重要的。因此，本建议的动机是调查，实验和分析，砌体填充墙的行为和能力，重点是混凝土砌块砌体填充。填充墙的刚度，强度和破坏模式将研究各种材料，几何和负载特性。这项研究，在其完成后，预计将有助于推进一个合理的设计方法，砌体填充墙和相关的填充框架，并提供建议，实际执行。

Masonry infill walls are commonly used as interior partitions as well as exterior wall infills in both steel and reinforced concrete frames in modern building construction. Due to the lack of scientific information in quantifying the extent of composite action between the infill and the frame, the common design practice applied in industry has been to treat masonry infill walls as non-structural elements and to design frames for both gravity and lateral loading. The contribution of masonry infill walls to the frame stiffness and strength is therefore ignored. It is, however, a misconception that ignoring the contribution of the infill wall is a conservative approach. Infill walls significantly stiffen the frame and thus reduce its ductility, which in turn attracts larger forces to the infill region in a structure. The poorly designed infill walls have been identified as a contributing factor to catastrophic structural failures in earthquakes. Although the current Canadian masonry design standard CSA S304 provides equations for the consideration of infill stiffness and strength, the values obtained using these equations are found to be in disparity with those obtained from experimental testing conducted by various researchers and also with values obtained from other recognized codes such as New Zealand masonry code NZS 4230 and Eurocode 8. In order to incorporate masonry infills in the design of lateral and gravity load resisting systems of a structure, the rational and accurate evaluation of their stiffness and strength is crucial. This proposal is therefore motivated to investigate, both experimentally and analytically, the behaviour and capacity of masonry infill walls with the focus on the concrete block masonry infills. The stiffness, strength and failure modes of infill walls will be studied for various material, geometric and loading characteristics. This research, upon its completition, is expected to contribute to the advancement of a rational design approach for masonry infill walls and associated infilled frames and to provide recommendations for practical implementation.