Etoori Keerthana received her MS-Dual Degree in Civil Engineering (CE). Her research work was supervised by Prof. Pradeep Kumar Ramancharla.
Here’s a summary of Keerthana’s M.S thesis, Performance assessment of buildings designed with SSI and without SSI as explained by her:
This study consider low (5-storey), medium (10-storey) and high-rise (20-storey) buildings founded on hard, medium and soft soils according to IS code to show importance of soil flexibility in design. These 9 buildings designed for base shear obtained from IS 1893 (Part-1)-2016, fixed base and flexible base respectively show that buildings designed according IS code are over designed when compare with flexible base. To check safety of these overdesigned buildings linear dynamic analysis and pushover analysis were performed. These analysis show that flexible base design is safe and economic than IS code and fixed base design buildings.
Introduction
Soil-structure Interaction exist because of soil flexibility. Base flexibility is due to combined stiffness of sub-structure and soil at its bottom. Different type of soils at base of foundation introduces different flexibility at base of structure. Base flexibility contribute to resist lateral loads compare to gravity loads. In general, building design practice assume bottom of building is always fixed but in reality every building is on soil which has stiffness not equal to fixed conditions.
This study compares behavior of buildings designed according to IS code with buildings designed for flexible base i.e., on hard, medium and soft soil respectively. Also check safety of these buildings using linear dynamic analysis and pushover analysis. These analysis show that buildings designed for respective soil base condition are safe and economic compare to IS code buildings.
This study considers three models based on design i) IS code model, where buildings designed for base shear obtain from IS1893:2016 natural period ii) Fixed base model, where buildings designed for base shear obtain from fixed base computer model natural period iii) Flexible base models, where buildings designed for base shear obtain from respective flexible base natural period.