ESTIMATION OF SETTLEMENT OF FOUNDATIONS -A COMPARATIVE STUDY

Abstract

Foundation design consists of two key calculations (i) assessment of ultimate bearing capacity and (ii) estimation of settlement under working loads. In the case of foundations on cohesionless soils, the estimation of settlement is based on the results of in-situ tests such as standard penetration test (SPT), static cone penetration test (SCPT), dynamic cone penetration test (DCPT), pressure meter test (PMT) etc. There are a few methods widely adopted in practice to estimate the settlement of foundations on cohesionless soils based on the results of SPT and SCPT such as Peck.et.al (1974), Burland and Burbidge (1985) (using SPT), De-Beer and Marten (1957), Schmertmann (1978) (using SCPT) methods. A user friendly computer package to estimate settlement of footings, raft and Pile foundation based on these methods has been developed using Visual Basic 6.0. The package takes into account the usually encountered field situations such as layered soils, shape of foundations, position of water table, etc. Using the package, settlement has been estimated for various typical SPT and SCPT data by the above methods and the results are compared. Further, reported case studies involving measurement of settlement are, compiled and estimated settlements are compared with the measured values.