Enhancement of Unreinforced Masonry Walls for In-Plane and Out-of-Plane Loading During Seismic Events Using Advanced Fiber Reinforced Polymer (FRP) Systems

摘要

Unreinforced masonry infill, bearing and shear walls are common in nuclear power generation sites and are often vulnerable to in- and out-of-plane loading generated by earthquake events. The seismic susceptibility of these structural elements is often unacceptable as such elements are frequently located in areas crucial to the safe operation of a nuclear station (i.e. control room walls). This paper will explore the advancements made in retrofitting unreinforced masonry walls with advanced fiber reinforced polymer systems to withstand the non-gravity loading of a seismic event. When properly installed to one or both sides of a URM wall, FRP acts as lightweight structural laminate that exhibits high uni- or multidirectional tension strength. In design, FRP elements are utilized as high strength tension members, whose maximum performance are governed by existing wall characteristics such as available application area and masonry unit material composition. FRP materials may be used to enhance performance in out-of-plane flexure, in-plane shear, in-plane flexure, in-plane shear transfer at boundary elements, fall protection or wall stabilization, and maintaining overall elastic seismic response. This paper will report the findings of full scale URM wall testing performed at the University of British Columbia and TVA sponsored testing at the US. Army Construction Engineering Research Laboratory (USA CERL), including initial capacities and strengthened capacities after application of FRP materials in different configurations.