SEISMIC VULNERABILITY ASSESSMENT OF 125M HIGH RCC CHIMNEY UNDER INDIAN EARTHQUAKES (KEY IJP************892)

• Nikhil Prakash,Mirza Aamir Baig

Abstract

Evaluation of seismic vulnerability of very flexible structures such as high-rise petrochemical and refinery stacks (chimney) and power plant chimneys are a challenging problem in earthquake engineering. Their equipment and structures are often considered as vital facilities and thus they must be fully functional after even very strong ground motions. From other point of view, numerical modelling of such mega-structures with numerous elements may not allow to consider all details of mechanical characteristics of consisting materials, particularly nonlinear performance of elements during large deformations. Therefore, a simplified model corresponding to dynamic characteristics of whole structure is substantially needed to investigate seismic performance and failure modes of these essential structures subjected to strong ground motions. The procedure for developing a 2-D simplified nonlinear model based on moment-curvature in some plane-sections of a 3-D sophisticated model but linear system having almost identical dynamic properties is discussed. However, basic dimensions of industrial RC chimney, such as height above ground, the diameter at top, etc., are generally derived from the respective national environmental provisions for where the structure is to be built. The objective of the present study is to investigate the vulnerability reinforced concrete chimney under various Indian earthquakes.