Earthquake Analysis of High rise Building Using Birdcage Interlocking Frame with Combination of Shear Walls

Abstract

Earthquakes are among the most deadly natural hazards. There are around 100 earthquakes each year of a size that could cause serious damage. Earthquakes strike without warning and many of the Earth’s earthquake zones coincide with areas of high population density. When large earthquakes occur in such areas the results can be catastrophic, with terrible loss of human lives and untold economic cost. To overcome due to seismic and wind loads, providing birdcage like structure around the building which consists of steel sections (like I-sec, C-sec, & etc.) It protects the building by providing cage around the structure at elevation which prevents the structure from deflection or displacement of building due to wind and seismic loads. Some buildings have supporting steel frames that interlock called Birdcages. Steel is more flexible that brick and concrete. This allows the frames to bend, rather than break, under the force of an earthquake. The basic principles of design for vertical and lateral loads (wind & seismic) are the same for low, medium or high rise building. But a building gets high both vertical & lateral loads become controlling factors. The vertical loads increase in direct proportion to the floor area and number of floors. In contrast to this, the effect of lateral loads on a building is not linear and increase rapidly with increase in height. Due to these lateral loads, moments on steel components will be very high. One of the most important aspects is to construct a building structure, which can resist the seismic force efficiently. Study is made on the different structural arrangement to find out the most optimized solution to produce an efficient safe earthquake resistant building. The extent of the damage depends on the strength of the vibrations or the energy associated with them. It also depends on the density of population and the way buildings are constructed. An Educational package ETABS has been utilized for analysing high-rise building of 66.5m height and for different zones. The results of the analysis on the shear force, bending moment and Torsion are compared. The results are presented in tabular and graphical form.