OUT-OF-PLANE BEHAVIOUR OF FRAMED-MASONRY WALLS WITH OPENING AS A RESULT OF SHAKING TABLE TESTS

Reinforced concrete frame structure infilled with masonry walls was built in a scale 1/2.5 and tested on shaking table under earthquake excitation. It consisted of three storeys with two longitudinal frames in the direction of earthquake excitation and three transverse bays perpendicular to the direction of earthquake excitation. The both longitudinal and central transverse reinforced concrete frames were infilled with masonry walls throughout the entire height of the structure. The masonry walls were made of clay block masonry units and masonry mortar. The structure model was excited in sequences with increasing earthquake peak acceleration by each sequence. Observed were masonry walls placed in the central transverse bay that were exposed to the out-of-plane excitation. They had door opening in the ground floor and window openings in the first and the second floor. The existing simplified model to verify the out of plane resistance of complete masonry walls without openings was applied before the tests. As the tests revealed, they incorrectly estimated their resistance since different failure mechanisms occurred. Position of the failed infilled masonry wall with opening and its failure mechanisms were opposite to the current perceptions for out-of-plane infilled walls behaviour. Detailed description of observed behaviour and measures that could be used for improvement of their behaviour under earthquake excitation is presented.