The Behavior of Foundations During Construction

This paper is based on an extensive study of foundations on the M.I.T. campus. Measurements of pore pressure and movement of foundations on the campus are presented, some of the fundamentals of foundation behavior during excavation are identified, and predicted and measured performances compared. Most of the heave was caused by strains in the overconsolidated soil immediately below the surface of the excavation. Most of the heave was time-dependent, i.e., consolidation heave. Compressive horizontal strains occurred in the foundation soil during both the initial heave and the consolidation heave. Theoretical predictions of performance resulted in: (1) An underprediction of initial head drop; (2) an underprediction of consolidation rate; (3) a close prediction of total head at the end of the excavation period; and (4) an overprediction in both initial heave and consolidation heave.