Volume 8 Issue 3 - May 2017

  • 1. Analysis of raft foundation using finite element approch

    Authors : Swati Limkar, Dr. M. G. Kalyanshetti, Dr. S. A. Halkude

    Pages : 14-28

    DOI : http://dx.doi.org/10.21172/1.83.003

    Keywords : Rigid Raft Foundation, Safe bearing capacity of soil, Conventional approach, Finite element approach, Deflection, Moment, Soil pressure, Soil modulus of elasticity.

    Abstract :

    Normally, a structure resting on soil having low bearing capacity and where differential settlement due to erratic nature of soil is expected, raft foundation is recommended to cope-up with mixed or poor ground condition and simultaneously to transfer heavy loads to ground while controlling the differential settlement. The essential task in the analysis of a raft foundation is the determination of the distribution of contact pressure underneath the raft which is a complex function of the rigidity of the superstructure, raft itself and supporting soil .The IS : 2950 (Part I )-1981 recommends the analysis based on the assumption of liner distribution of contact pressure. However due to complex / erratic nature of soil & flexibility of the raft, this assumption is away from reality, which will leads to erroneous results. Therefore in order to ensure precision in the analysis and to simulate the realistic condition of interface of soil mass and raft, a discretization of raft is done using finite element method and springs are used below the node points to realistically simulate the soil flexibility. The application software (SAFE 2000) is used for finite element analysis .In this study the attempt is made to evaluate the effectiveness of finite element approach by studying moments along x direction, moment along y direction and soil pressure beneath the raft. This study is carried out on three types of soil; loose, medium and hard soil. Study reveals that finite element formulation minimizes the error to the significant extent in the results due to correction in assumption of liner pressure distribution. Study also reveals that finite element approach is found effective in case of loose and medium soil as error is magnified due to the assumption of liner pressure distribution in conventional approach.

    Citing this Journal Article :

    Swati Limkar, Dr. M. G. Kalyanshetti, Dr. S. A. Halkude, "Analysis of raft foundation using finite element approch", https://www.ijltet.org/journal_details.php?id=914&j_id=3724, Volume 8 Issue 3 - May 2017, 14-28, #ijltetorg