Ivica Guljaš

Cyclic testing of single bay confined masonry walls with various connection details

The test results of nine confined masonry wall specimens, with three different connection details between the masonry and the tie-columns and one unreinforced masonry wall, are presented. The specimens were executed and were tested under constant vertical and cyclic lateral loads. Failure modes, hysteresis loops, resistance envelope curves, averaged evaluated bilinear response envelope curves and behaviour factors were all obtained. Confinement brought an increase in the stiffness, lateral load capacity, ductility and hysteretic energy dissipation of the walls. The connection details did not influence the initial stiffness or the maximum lateral resistance, but they did improve the nonlinear wall behaviour, behaviour factors and hysteretic energy dissipation. They also helped in activating the whole wall for lateral load resistance and maintained its composite behaviour well into the nonlinear range. The measured behaviour factors of all the specimens were above the values suggested by the Eurocodes. The analytical expressions available differed from the prediction quality of the measured results.

Dynamic Tests of a Large-Scale Three-Story RC Structure with Masonry Infill Walls

ABSTRACT RC buildings with masonry infill walls are common throughout the world. There is uncertainty about the effect of the infill walls on the response of the building to earthquake demands. To shed light on this issue, a three-story, scaled reinforced concrete frame with masonry infill walls was subjected to two sequences of base motions in two series of tests. In Series 1, hollow masonry units were used. After completion of this series, the structure was repaired by replacing hollow masonry units with new solid units. Reinforced concrete confining elements were also added along the vertical edges of window and door openings in the first and second stories. The repaired structure was then tested with the same sequence of base motions in Series 2. On average, drift demands were 30% smaller in Series 2 and were nearly half what the drift demands were estimated to be for the bare RC frame alone. These results support the hypothesis that masonry infill panels can be used to control drift in low-rise structures, provided they do not cause column failures and provided they are restrained from out-of-plane collapse. Projections made based on the test results also support the idea that a Wall Index (ratio of masonry wall density to ten times the number of stories) exceeding 0.2% leads to acceptable earthquake response in low-rise buildings.

SIMPLIFIED APPROACHES FOR MODELING INFILLED FRAMES

In many seismic areas, reinforced-concrete frames are filled with masonry infill walls. The behavior of these structural composite systems are difficu

UZAJAMNI UTJECAJ AKTIVNOSTI LJUDI I VIBRACIJA MEĐUKATNIH KONSTRUKCIJA

Međukatne konstrukcije poslovnih i stambenih zgrada mogu biti izložene djelovanju dinamickih sila uzrokovanih ljudskom aktivnoscu tijekom hoda i