UBC Theses and Dissertations
In-plane shake-table testing of unreinforced masonry walls strengthened with fibre reinforced-plastics Turek, Martin Edward
Unreinforced-masonry structures have typically performed poorly during earthquakes. Many structures that were built with this material still have a continued economic and social benefit, even though they may be structurally unfit. For this reason, many seismic retrofit schemes have been developed, one being the use of composite materials. Various testing has been performed on these materials, and on some of their structural applications in seismic retrofits. Limited full-scale shake table testing has been performed, and a research collaboration between The University of British Columbia and Public Works and Government Services Canada, Pacific Region was established to explore this type of testing on the application of these materials. A series of in-plane shake-table tests were performed on a set of unreinforced and FRP strip reinforced concrete-masonry walls. The unreinforced walls were used as a benchmark for the study, and five different configurations of FRP strip reinforcing were tested. The walls were subjected to code-level and near-code level to determine their behaviour at design levels. Then the walls were subjected to extreme-level records until failure, to determine the failure modes and behaviour of the various reinforcing schemes. It was observed from the testing that all of the strengthened specimens, regardless of reinforcing configuration, performed well during the application of the code- and nearcode level records. Four of the five reinforcing configurations also performed well during application of the extreme-level record. It was concluded from these tests that the use of vertical FRP strips is an adequate reinforcing configuration to improve the in-plane performance of URM walls. The behaviour of vertical strips was comparable to that of horizontal strips, which were also tested and found to be very effective. The vertical strips were found to be effective in repairing damaged walls. They were also found to help control the failure modes of the specimens, and prevent collapse even after severe damage had occurred. This can be a strong contributor to improving life-safety during a severe event.
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