Construction sequence analysis of multi-storey setback building placed in slope with p-delta and time-dependent effects

Analysis and design of the structure are the most critical steps in the pre-construction steps involved. Nowadays, as technology is well developed, there is plenty of software available to carry over the analysis and design of any structures in a short period. In every software, the building model with all storey will be modelled, and loads are applied to the modelled structure on respective members, and their responses will be studied for the whole structure. But in reality, the building will be constructed in sequence as a step-by-step process, i.e., storey after storey with their respective loads, which may produce different responses. This analysis with sequential loading at each step is called Construction Sequence Analysis (CSA). In the present project work, the ten-storey setback building with a built-up area of 25m x 30m placed on the slope of 10°, assumed to be situated in Darjeeling, is modelled in ETABS software. The loads, namely gravity and lateral loads are applied to the developed model. Then the model is analyzed for different loads and their combinations as prescribed by IS codes. The combinations that produce high response are selected and dead load in those combinations are replaced with three modes: CSA without P-Delta effect, CSA with P-Delta effect, and CSA with P-Delta and Time-dependent effects combined. Thus the model is analyzed with these three additional combinations along with selected conventional load combinations. The various comparisons such as storey displacement, and storey drift between these four combinations of analysis were studied, and results were discussed. The building design is also done based on the analysis performed.