Effects of Staircase on the Seismic Behavior of RC Moment Frame Buildings

Staircase is an architectural element which has high potential to change structural behavior especially moment frames against lateral forces, while it is usually neglected in structural design and it is not included in the model of structure [1, 2, 3, 4, 5, 6]. In fact, what is included in modeling structure of conventional buildings, are beams and columns around the staircase as a void and applied dead and live loads [2, 3, 5]. Due to importance of the staircase in crisis and disasters as a way of escape and rescue routes [1, 2, 4, 6, 7, 8, 9, 10] and maintaining its function after the earthquake, it is necessary to pay special attention to the effects of the staircase in structural analysis and design, in a way that not only does no damage to structures, but also in the event of damage to the structures, this part of building remains intact and in service. Seismic behavior of staircase in two aspects of its structure and its impact on the master structure can be studied and analyzed. It should be mentioned that the main causes of damage to the staircase are ignoring the staircase in structural design and construction faults including poor quality of landing and stair turret, poor quality of welding and insufficient length of welding in landing beam of steel structures, not using special confining reinforcement over the full height of reinforced concrete columns of landing, and occurring short column. The main aim of this research is to study the effects of staircase on structure in design phase. In the following paragraph, the previous research is briefly reviewed. EFFECTS OF STAIRCASE ON THE SEISMIC BEHAVIOR OF RC MOMENT FRAME BUILDINGS