Seismic Strengthening of Unreinforced Masonry Structures with Fiber Composite Fabrics

该项目得到了探索性研究小额赠款(SGER，手册NSF-89-85)计划的支持。复合材料由于具有较高的抗拉强度、耐久性和优异的疲劳性能，在土木工程建设中得到了越来越多的应用。其中一种应用涉及使用玻璃纤维加固、薄板或钢丝对现有结构进行抗震修复或加固。这种技术的一些成功已经在世界各地的几个案例应用中得到证明。玻璃纤维加固技术在梁、桥柱墩等钢筋混凝土结构构件加固中的应用已取得成功。然而，这种类似应用于未加固砖石建筑(URM)的可行性还没有得到认真的探索。URM建筑是美国最容易受到地震危害的现有建筑之一。这个项目涉足了这样一个新的研究领域，在这个领域，有可能开发一种技术合理且成本效益高的工程措施来加固国家地震区现有的URM建筑。本探索性研究项目的目的是论证将环氧基复合纤维粘贴到结构外表面对URM结构进行抗震加固的可行性。研究的重点是：(A)确定复合织物与砌体的粘结性能；(B)研究玻璃纤维作为低成本加固材料的有效性。

This project is supported under the Small Grants for Exploratory Research (SGER, Brochure NSF-89-85) Program. Due to their high tensile strength, durability, and superior fatigue behavior, composite materials have been increasingly applied in civil engineering constructions. One of such applications involves the use of fiber-glass reinforcement, sheets, or wires for seismic repair or strengthening of existing structures. Some success of such techniques has been demonstrated in several case applications around the world. The use of glass-fiber reinforced techniques have been successfully tested in strengthening of reinforced concrete structural members such as beams and bridge-column piers. However, the feasibility of such similar applications to unreinforced masonry (URM) buildings--one of the nation's most vulnerable existing building stocks to seismic hazard--has not been seriously explored. This project ventures into such a new research area where there is a potential to develop a technically-sound and cost-effective engineering measure to strengthen existing URM buildings in the nation's seismic regions. The objective of this exploratory research project is to demonstrate the feasibility of seismic strengthening of URM structures by epoxy-bonding composite fibers to the exterior surfaces of the structure. The focus of the study are: (a) to determine the bond behavior of composite fabrics to masonry, and (b) to study the effectiveness of glass fibers as low- cost reinforcement materials.