A lowrise office building was constructed on a mat foundation over a thick peat deposit that had been preconsolidated beneath surface fill. Environmental restrictions prevented use of deep foundations for fear that penetration through an aquaclude would permit contamination of a deeper water table. This paper describes the laboratory testing and field instrumentation programs, as well as the special geotechnical and structural analysis undertaken for the design and construction of this project. Included in the program were long-term consolidation tests, pressuremeter tests, use of heave markers, inclinometers and pore pressure piezometers. A site history was also developed to define the extent and nature of the surficial fill. To achieve much of the anticipated initial settlement, the basement was temporarily flooded, thus preloading with the full building weight. Water was removed as construction proceeded so that the full building weight was always maintained. Actual settlement was observed to agree fairly well with predicted settlements
