Distress Investigation and Retrofit of a Pyramid-Shaped RC Building for Thermal and Seismic Effects

Abstract

Seasonal variation of ambient temperature is rarely a cause of concern in structural design of normal buildings, but it has been found to cause recurring distress in a pyramid-shaped reinforced concrete (RC) building located in the foothills of the Himalayas. Abnormal stresses developed because of thermal movement of a large inclined roof exposed to direct sun and anchored to short columns at corners. Integral connection of a long corridor with the building compounds the effect of thermal movement of the building and corridor in opposite directions. A conventional linear analysis cannot correctly predict the observed distress. However, nonlinear analysis predicts the distress in close agreement with the observations. The building is situated in an area of high seismicity, and the inclined roof has a peculiar effect on the seismic response of the building, resulting in soft story phenomenon. Alternative retrofit schemes to safeguard the building against thermal and seismic actions are evaluated. It is observed that some of the retrofit strategies that are suitable for temperature effects may not be suitable for earthquake action.