Seismic Characteristics of Concrete Plank Diaphragms

在美国和世界上，砖石结构占建筑结构的很大一部分。加筋砌体以其经济、防火、建筑灵活、施工方便等明显的特点，在中、高震区的应用越来越多。砌体结构分析和设计、材料和施工技术的现状不能准确预测建筑在侧向荷载（如地震荷载）下的性能。在美国，砌体建筑的设计和建造方法、规范和标准依赖于工作应力方法、经验规则和确定允许应力值的可疑方法的混合。砌体也是一种复杂的建筑材料，因为大量的设计和施工变量会影响最终产品的结构及其在地震荷载下的反应。为了描述砌体建筑的地震反应，有必要建立基本的知识库，以确定符合安全和经济要求的基本设计方法。本研究项目考察了混凝土板膜片的特性，并考虑了支承构件刚度变化对膜片作用的影响。这是通过用砖石墙代替工字钢梁来实现的。数据用于确定强度、地震行为特征和破坏模式。确定了一种分析模型来描述这类系统。研究结果为砌体结构试验数据与实际系统之间的联系提供了依据。该项目是美日砌体建筑研究协调计划和砌体研究技术协调委员会计划的一部分。

Masonry construction comprises a large portion of building construction in the U. S. and the world. Reinforced masonry construction use is increasing in moderate to higher seismic zones because of its apparent features of economy, fire safety, architectural flexibility and ease of construction. The present state of masonry structural analysis and design, and materials and construction technologies does not enable an accurate prediction of building behavior under lateral loads such as seismic loads. In the U.S., masonry buildings are designed and built with methods, codes and standards that rely upon a mixture of working stress methods, empirical rules, and questionable methods for determining allowable stress values. Masonry is also a complex building material because of the large number of design and construction variables which influence the final product configuration and its response under seismic loads. In order to describe the seismic response of masonry buildings it is necessary to develop the fundamental knowledge base to determine basic design methodologies consistent with safety and economic requirements. This research project examines concrete plank diaphragm characteristics and considers the effect on diaphragm action of a change in the stiffness of the supporting members. This is done by substituting masonry walls in place of steel I-beams. Data are used to determine strength, seismic behavior characteristics, and failure modes. An analytical model is determined to describe this type of system. The results of the research provide a link between experimental data and actual systems which are used in masonry structures. This project is part of the U.S.-Japan Coordinated Program for Masonry Building Research and the Technical Coordinating Committee for Masonry Research (TCCMAR) Program.