In-plane and out-of-plane behaviour of concrete masonry infills

混凝土砌体填充物的面内和面外行为

• 批准号: RGPIN-2015-04078
• 负责人: Liu, Yi
• 金额: $ 1.46万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=612762
• 关键词: plane; out; behaviour; concrete; masonry

Masonry walls have been commonly used to infill steel or reinforced concrete frames either as interior partitions or exterior cladding in modern building construction. Due to a lack of scientific information in assessing the extent of interaction between the infill and the frame, the masonry infill is often treated as non-structural element and the bounding frame is designed for both gravity and lateral loading. The contribution of masonry infills to the frame stiffness and strength is therefore ignored. It is, however, a misconception that ignoring the contribution of the infill is a conservative approach. Infill walls significantly stiffen the frame, which in turn attracts larger forces to the infill region in a structure. Improperly designed Infill walls have been identified as a contributing factor to catastrophic structural failures in earthquakes. On the other hand, properly designed infills have shown to provide significant strength and ductility for the frame system in resisting various types of lateral loads-even after considerable cracking. The nonlinear, inelastic behaviour of the frame system coupled with the various material and geometric characteristics of masonry infills has made accurate evaluation of the infill contribution to the lateral stiffness and strength of the infilled system a challenge. Despite that much experimental testing and numerical analysis have been conducted in the past three decades, the results have been scattered and some findings from these studies were either inconclusive or even conflicting. The design guidelines for masonry infills contained in the Canadian masonry design standard, CSA S304.1-04 (2004), are based on work conducted more than 40 years ago. The design values obtained using these guidelines are found to be in significant disparity with existing experimental results and also with values obtained from other recognized standards such as American code MSJC 2013, New Zealand masonry design code NZS 4230 and Eurocode 8. These inconsistencies have resulted in the situation that research findings have not been transferred to industry practice to a large degree. In order to incorporate masonry infills in the lateral and gravity load resisting systems of a structure, scientifically verified and industry-accepted design guidelines that cover practical applications of infills are crucial. This proposal is hence motivated to investigate, both experimentally and analytically, the behaviour and capacity of concrete masonry infills bounded by frames so as to contribute to advancement of rational design approaches. The research, upon its completion, is expected to quantify the infill and frame behaviour with a range of parameters to a point that constructive recommendations applicable to industry practice can be made. This will fill in the gap in the current standard which will ultimately impact the current masonry infill construction practice.

砌体墙通常用于填充钢或钢筋混凝土框架作为内部分区或现代建筑建筑中的外部覆层。由于缺乏评估填充填充物与框架之间相互作用程度的科学信息，因此通常将砌体填充物视为非结构性元素，并且边界框架设计用于重力和侧向载荷。因此，砖砌填充对框架刚度和强度的贡献被忽略。但是，误解是忽略填充物的贡献是一种保守的方法。填充壁显着加强了框架，从而在结构中吸引了更大的力到填充区域。设计不当的填充墙已被确定为导致地震中灾难性结构性故障的促成因素。另一方面，精心设计的填充物已证明可以为框架系统提供明显的强度和延展性，以抵抗各种类型的横向载荷 - 甚至在大量裂纹后也可以。 框架系统的非线性，非弹性，以及砖石填充物的各种材料和几何特性，使填充物对填充物对填充刚度刚度和强度的贡献进行了准确的评估。尽管在过去的三十年中已经进行了许多实验测试和数值分析，但结果已经散布，这些研究的一些发现尚未定论，甚至是冲突。加拿大砌体设计标准中包含的砖石填充填充剂的设计指南，CSA S304.1-04（2004），基于40年前的工作。发现使用这些准则获得的设计值与现有的实验结果有很大的差异，并且还具有从其他公认的标准中获得的值，例如美国代码MSJC 2013，新西兰砌体设计代码NZS 4230和Eurocode 8。这些不一致之处在于研究发现并未转移到行业练习的情况下。 为了将砌体填充物纳入结构的横向和重力载荷系统，经过科学验证和行业所接受的设计指南，涵盖填充物的实际应用至关重要。因此，该提议是在实验和分析上进行调查的促成，即通过框架界定的具体砌体填充物的行为和能力，以促进理性设计方法的发展。该研究完成后，有望用一系列参数量化填充填充物和框架行为，以便可以提出适用于行业实践的建设性建议。这将填补当前标准的空白，这最终将影响当前的砌体填充构建实践。