Effect of intra planar differential settlement analysis of boiler supporting structure - A case study

Abstract

In boiler supporting structure, heavy loads are transferred to the ground through several columns embedded in reinforced concrete foundation. The foundation gets settled due to various factors such as loads acting on the structure, calamity, consolidation, nature of soil, fluctuations in ground water table etc. Due to this settlement, there occurs phenomenal changes in the geometry of the structure and hence, the force transfer mechanism within the structure cannot be predicted. This paper presents the effect of differential settlement on the foundation loading for a typical boiler supporting structure using STAAD - III. It is observed that there is significant effect on the vertical loading of the foundation due to the differential settlement that is obtained from a total of three hundred and seventy five trials. It is suggested to incorporate the increased variation of load caused due to settlement in the design itself such that the superstructure/foundation corresponding to that settlement is tolerated. It is concluded that if the foundation is designed for 10% extra load, it can withstand a differential settlement of 6mm safely. This extra load is the typical value obtained for this structure from varied set of combination of settlements and hence not applicable in general for any structure and any loading.