Effect of shear wall on behaviour of mat foundation

Abstract

Mat foundation is widely used for high-rise buildings where presence of shear wall is very common. But the available analysis and design methods do not properly focus on the effect of shear wall on the behaviour of mat foundation. Shear Wall resists a major portion of the lateral load of high-rise buildings. So, presence of shear wall on mat foundation causes significant change in pattern and intensity of loading on mat foundation. Proper understanding of shear wall effect on mat foundation has not been duly addressed in the past. This gap in knowledge brings some uncertainty in analysis of mat foundation and may result in its over design or unsafe design. For economy in design of mat with shear wall requires comprehensive understanding of the influence of shear wall on mat. This work involved an extensive investigation of shear wall effect on mat foundation using finite element program, ANSYS, Effects of different locations and different numbers of shear walls have been studied. A parametric study has been made in order to identitY the sensitivity of some parameters for the presence of shear wall on mat. Variation in response of different parameters to shear wall loading has been compared with past parametric studies of mat without shear wall. Non-uniform thickness of mat has received some attention among design engineers for economy. Shear Wall effects on both uniform and non-uniform thickness have, therefore, also been studied. For non-uniform mat analysis, the configuration suggested by Rahman and Morshed has been followed. Shear wall presence on mat foundation has significant effect on the behaviour of mat in some cases. Presence of shear wall on edge of mat foundation has been found to be very significant. Behaviour of mat foundation with and with out shear wall has been compared. Based on the type and magnitude of variation, design recommendations for mat foundation with shear wall have been suggested.