Behaviour and design of concrete masonry infill walls

在现代建筑结构中，在钢框架和钢筋混凝土框架中，砖石填充墙通常用作内部隔断和外墙填充。由于缺乏科学信息来量化填充物和框架之间的复合作用程度，工业上常用的设计实践一直是将砌体填充墙视为非结构构件，并在重力和水平荷载作用下设计框架。因此，砖石填充墙对框架刚度和强度的贡献被忽略。然而，忽视填充墙的作用是一种保守的方法，这是一种误解。填充墙显著地使框架变硬，从而降低其延性，进而将更大的力吸引到结构中的填充区域。设计糟糕的填充墙已被确定为地震中灾难性结构破坏的一个促成因素。虽然加拿大现行的砌体设计标准CSAS304提供了考虑填充物刚度和强度的公式，但使用这些公式得到的值与许多研究人员进行的试验测试得到的值以及其他公认的规范(如新西兰砌体规范NZS4230和欧洲规范8)得到的值不一致。为了将砌体填充物纳入结构的横向和重力荷载抗力体系的设计中，合理和准确地评估其刚度和强度是至关重要的。因此，这项建议的目的是从试验和分析两方面研究砌块填充墙的性能和能力，重点是混凝土砌块填充。针对不同的材料、几何和荷载特性，研究填充墙的刚度、强度和破坏模式。这项研究完成后，预计将有助于推进砖砌填充墙和相关填充框架的合理设计方法，并为实际实施提供建议。

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.