Seismic Performance of Hyperbolic Paraboloid and Inverted Spherical Shell Foundation

The performance of shells in roof structures initiated the idea of using shells as foundations. Foundations should be structurally strong to resist the distress, bearing capacity failure and excessive settlement due to earthquakes. Shallow foundations which are generally the first preference in foundation design under favorable conditions are generally more vulnerable to earthquake damage. Among shallow foundations, shell foundations are expected to perform better as they are an economic alternative to plain foundations where heavy super structural loads are to be transmitted to weaker soils. There are various types of shells are used in foundations like hyperbolic paraboloid shell, conical shell, inverted dome, elliptic paraboloid, pyramidal shell, triangular shell, cylindrical shell, inverted spherical shell etc. Considering the aspects of a shell foundation, in this paper, the seismic performance of the inverted spherical shell foundation and hyperbolic paraboloid shell foundations were investigated by varying rise of shell with different contact conditions in both the clayey and sandy soils using finite element software ANSYS 16.1. Seismic performance of inverted spherical shell foundation and hyperbolic shell foundation was done considering the Acceleration-time history of El Centro Earthquake of USA in 1940.