Case of Residential Foundation Failure and Preservation by Grouting

Abstract

The purpose of this paper is to describe the causes of distress to the foundation of a residential building, and to discuss the remedial options. The northeast corner of the building had settled excessively. Many cracks were noted on the foundation walls and the basement slab. The north foundation wall had been separated from the floor slab at the rear corner. After completion of a subsurface investigation program, procedural and technical factors causing the failure are identified. One of the factors that contributed to the failure of the foundation included the placement of river bank run gravel overlying a layer of likely uncontrolled fill that was placed during the backfilling of a utility sewer line in the proximity to the failed foundation. The importance of construction monitoring and inspection by qualified personnel as well as close supervision by project manager are verified. After considering the remedial options, a foundation grouting procedure was selected. The pressure grouting was found to be very effective in mitigation of shortand long-term foundation settlement.