Structural system of safe house against tornado and earthquakes

Abstract

Every year earthquakes, tornadoes and other extreme windstorm cause fatalities or even kill people, devastate and millions of dollars worth of property. The likelihood that a tornado will strike building is a matter of probability. The study describes the analysis and design, the engineering process the new type of tornado safe room (Fig. 1) according to the FEMA guidance. It also evaluates the effects of in-fill frames and the linear response of reinforced concrete braced frames and comparison with frames with shear wall. The main conclusion drawn from this study is to elaborate that the masonry in-fills, are strongly influence the structural seismic response and contribute to the overall stiffness and can decrease drifts and displacements. Infill walls have significant role in the strength and ductility of RC framed structures and should be considered in both analysis and design globally. These walls make the structure significantly stiffer, and reduce the natural period of the structure. Locally, infill walls changed the load path, the distribution of forces between different elements of the structure, and the change the demand of forces on their adjacent elements of the bounding frame. Due to the high relative stiffness of the infill frames, they act as the main lateral load-resisting system and attract larger portions of the earthquake and tornado induced inertia forces.