Bearing Capacity Analysis of Piled Raft Foundation for Dhaka – Chittagong Elevated Expressway

Abstract

Bearing capacity is one of the most important characteristics of any kind of soil. For every construction work it is compulsory to calculate the bearing capacity of soil of study area for particular type of foundation. Bearing capacity is generally calculated by some conventional equations like Terzaghi’s bearing capacity equation and Meyerhof’s bearing capacity equation and for different types footings these equations vary. In this research extended sub-loading tij model for Finite Element Method (FEM) is used to calculate the bearing capacity of piled raft foundation. Elastoplastic constitutive model parameter identification is an important task for proper modeling of any soil. In this research, subsoil characteristics of study locations are presented based on field and laboratory test results. Elastoplastic constitutive model parameters of study locations soil has been determined for extended sub-loading tij model. In this study some soil parameters are determined from laboratory tests and by using these, simulation parameters like Compression index for FEM tij simulation (λ), Swelling index for FEM tij simulation (Ќ), Critical stress ration (RCs) and Void ratio at 98KPa (N) are calculated. Using these parameters, bearing capacity of piled raft foundation has been estimated for 0.05% settlement of soil section. Considering the effect of settlement in 2D Finite Element analysis have been conducted. It is found that bearing capacity determined.