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STORI..:;® Materials Technology Stork Twin City Testing Corporation PREREQUISITES FOR SOUND ENGINEERING PRACTICE In order to properly evaluate the foundation soils at a building site, it is imperative for our firm to know exactly where the building will be placed, its size, and the elevation of the foundation elements. Without this information, a judgment regarding the adequacy of the preparatory foundation earthwork is not possible. This project data is especially critical in situations when the excavation extends below the footing grade and compacted fill is required to attain building elevations. In these situations, the excavation would require lateral oversizing to provide suitable lateral distribution of the footing loads. Offset batter boards of the building lines stakes provide the best on-site verification of the building location and size. It must be recognized that Twin City Testing does not practice in the field of surveying. Therefore, we must rely on staking by others. If Twin City Testing is required to perform the survey, we will retain a licensed surveyor and invoice our client for the amount per our current fee schedule. Provision of the building foundation plans is also important so that we may properly perform our engineering judgments. If the construction is redesigned or otherwise moved subsequent to our work, we should be informed so our firm can assess if additional engineering observation is required or suggest sound engineering alternatives. We cannot be responsible for any soil foundation system if the structure has been relocated with respect to the excavation subsequent to our observations. GENERAL OVERSIZE REQUIREMENTS Because of the lateral distribution of foundation pressures with depth, lateral oversizing is required in an excavation where unsuitable soils extend below planned footing grade. The lateral oversize scheme provides compacted fill materials beyond the exterior footing limits where fill is required below footing elevation. The degree of lateral oversizing is dependent upon the surrounding soil's ability to resist lateral movement. Although we generally recommend the lateral oversize be at least 2' plus the depth of fill below bottom of footing elevation, each project must be evaluated separately. For example, in extremely compressible swamp or organic soils, the oversize should be increased to 5' plus twice the depth of excavation below footing grade. Due to the variations in the required oversize, an engineering judgment must be made to establish the necessary extent of the oversizing. Diagrams illustrating typical oversizing dimensions are included in this report. ii= twincitY test1na Stork Twin City Testing Corporation is an operating united of Stork Materials Technology B.V., T-. ......-:.,.. Amsterdam, The Netherlands, which is a member of the Stork group