Improper execution of modern code-designed structures in many developing countries have resulted in significant deficient building stock; low strength of concrete, reduced reinforcement, inappropriate detailing of beam-column members, and lack of lateral ties in joint panels. Observations based on earthquake-induced damages and experimental studies conducted on such buildings have revealed significant vulnerability of beam-column joints of bare moment-resisting frame structures. Shake table tests were conducted on selected three 1 : 4 reduced-scale three-story reinforced concrete (RC) moment-resisting frames, including one bare RC frame and two masonry-infilled RC frames, having relatively lower bay width-to-height ratio. The models were tested under multilevels of seismic excitations using natural acceleration time history of 1994 Northridge and also free vibration tests, to acquire the models’ dynamic characteristics, i.e., frequencies and elastic viscous damping, and seismic response parameters, i.e., roof displacement, interstory drift and interstory shear, and seismic response curves, in order to understand the role of masonry infill in the selected frames under moderate seismic actions. The inclusion of masonry infill avoided joint shear hinging of the frame. Additionally, the infill provided energy dissipation to the structure through masonry sliding over multiple cracks. This enabled the structure to control seismic displacement demand and resist relatively higher ground motions, yet limiting structural damages.
As the report of UN proposes that Evidence from past epidemics, including Ebola (2014-16) and Zika (2016) provide evidence that women have always been at greater risk of exploitation, sexual violence and poor health during pandemics. Coronavirus has wrecked mankind globally. Redefining existing societal, economic, healthcare orders, the previous being proved redundant. With humankind being struck by such a treacherous virus it is vital to embark on journey of combating mechanism which is robust and inclusive of new defined societal, health and communication tools which satisfy needs particularly of the vulnerable population. The vulnerable group this paper particularly talks about is women. Pandemic of such scale leads to ruinous impact on the health of women. Health is a holistic term, it may have different meaning for distinctive individuals, in diverse societies, depending upon the challenges of those societies. The definition of health as propounded by WHO is “health is a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity”.
Code requirements are usually fulfilled during the design of a building. On the other hand, reinforced concrete (RC) frames (particularly in the developing regions of the world) are found deficient due to unregulated constructions. Majority of such deficient structures lack shear reinforcement in beam-column joints. Collapse of these deficient buildings (as a result of limited ductility) triggered many socio-economic and human losses which is evident from recent earthquake disasters. This paper presents an experimental study which was conducted on a 1:4 reduced scale three-storey RC special moment resisting frame (SMRF) lacking shear reinforcement in the beam-column joints. The lack of confinement bars causes shear hinging of joints that reduces the displacement ductility of the frame. Shake-table tests were conducted on test model that was subjected to acceleration time history of 1994 Northridge earthquake, having a peak ground acceleration of 0.57g. The acceleration was linearly scaled to multiple levels and to sinusoidal base excitations of various frequencies and displacements. Moderate to severe damage at each storey level was observed in the joint panels due to the lack of lateral reinforcing ties in the joints. The data obtained from shake table tests were processed and analysed to develop a lateral force-deformation capacity curve, which was bi-linearized as an elasto-plastic curve to compute various response parameters of frame. The ductility factor (Rμ) of the tested model was found to be equal to 1.95, which is thirty-five percent less than the code recommended value of Rμ for RC SMRF structures.
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