Stability analysis of tilted multi-storeyed RCC buildings over alluvial soil: A non-linear static approach

Abstract

Tilt and settlement of mid-rise RCC buildings with shallow foundations in alluvial soil of greater Kolkata has become a common problem; affecting the overall stability of existing structures. Verticality assessment and non-destructive tests (NDTs) to assess strength & quality of concrete are practiced in real life situation; which cannot ascertain the building stability. Numerical modelling with fixed supports may address the stability issue to some extent, but the soil-structure interaction (SSI) plays a major role during earthquakes. Thus, stability analysis of various RCC buildings with different structural configurations and various tilts considering soil-structure interaction seems to be important for safety and future usefulness. This paper aims to evaluate the effect of various tilts on the overall stability of RCC buildings using non-linear static approach. Numerical study of building models on FE platform considering different foundation & soil types, nature & extent of tilts, building configurations etc. have been made and it is found that these parameters significantly affect the structural stability. Vulnerability indices are also evaluated for tilted buildings based on the pushover analysis results; to predict the repair feasibility. The present study seems to have a great scope for its practical application in safety evaluation and further retrofit of existing multi-storied tilted RCC buildings.