عنوان مقاله [English]
One of the main damages of the nonstructural masonry walls during an earthquake is its instability and collapse on the combination of deformation at in-plain direction caused by lateral inter-story drift of structures and out-of-plane inertial forces applied to the wall because of earthquake acceleration.
In most of the researches, only one of these actions were investigated and results were generalized to the performance of the wall. In some other researches at first the cyclic in-plain were applied to the maximum acceptable inter- story drifts and then monotonic out-of-plain loading applied until the wall failure. But recent shaking table tests under nonstructural walls show that these test method results do not match with shaking table test results and a new test method is needed for analyzing the nonstructural wall behavior under the earthquake loading.
In this research, for the first time in the country, combination of in-plane and out-of-plane loading was carried out and the effect of reinforcing walls separated from the structural frame by using fiber mesh-reinforced mortar and strengthening with bed rebar has been investigated.
For this purpose, 3 real scale nonstructural walls were made of Leca blocks and their behavior under the combination of in-plane cyclic deformation control loading and out-of-plane inertial forces were studied. The results of these tests were evaluated in the form of hysteresis diagrams, backbone curves, out of plane displacement-drift diagrams, failures and crack patterns. The results showed that separated wall without reinforcement, failed in lower drift and the test process was stopped. On the other hand, separating the wall along with strengthening by using textile reinforced concrete caused an increase of 15% and 54% in the drift ratio related to the reduction of the wall resistance and the maximum in plane force compared to the specimen which was separated and strengthened with bed joint reinforcement. Also, strengthening with textile reinforced concrete significantly reduced cracks.