Pseudo-static analysis of caissons to determine critical loading ratio

Abstract

Caisson foundations are massive foundations designed to support excessive vertical as well as lateral loads. Loads such as dead load of structure, live load of vehicles, buoyancy and vertical inertial forces due to earthquakes constitute vertical forces and forces caused by water, wind, soil and earthquakes account for horizontal forces. The relative magnitude of these forces may have a bearing on the response of the caissons under a given load combination. Based on this premise, the current study is carried out to determine the value of ratio of horizontal load to vertical load which gives optimum values of caisson responses like maximum bending moment. In the present study a rigid caisson embedded in cohesionless soil with an embedment ratio (ratio of embedment depth to diameter of caisson) of 3 is considered. The numerical modeling is done using Finite Element Analysis based software ABAQUS. Based on the analyses, the value of loading ratio for which magnitude of maximum bending moment comes out to be minimum is determined. This study will help in deciding the weight and thickness to maintain the obtained value of loading ratio of caissons in order to minimize the value of maximum bending moment. © 2019 Associazione Geotecnica Italiana, Rome, Italy.