SU0002478_SSNL - Laserfiche WebLink

Home Browse Search

SIGNET STL Project No. 0010771 Page 6 R!m ng Labs This compaction effort will stabilize the upper soils and locate any unsuitable or pliant areas not found during our field investigation. Groundwater Influence on Structures/Construction Based on our findings and historical records, it is not anticipated that groundwater will rise within the zone of structural influence or affect the construction of foundations and pavements for the project. However, if earthwork is performed during or soon after periods of precipitation, the subgrade soils may become saturated, pump or not respond to densification techniques. Typical remedial measures included discing and aerating the soil during dry weather, mixing the soil with dryer materials; removing and replacing the soil with an approved fill material; or mixing the soil with an approved time or cement product. Our firm should be consulted prior to implementing remedial measures to observe the unstable subgrade conditions and provide appropriate recommendations. Site Preparation General site clearing should include removal of vegetation, existing utilities, structures including foundations, basement walls and floors, existing stockpiled soil, trees and associated root systems, rubble, rubbish and any loose and/or saturated materials. Site stripping should extend to a minimum depth of two to four inches, or until all organics in excess of 3 percent by volume are removed. Deeper stripping may be required in localized areas. These materials will not be suitable for use as Engineered Fill. However, stripped topsoil may be stockpiled and reused in landscape or non- structural areas. Following stripping operations, the upper 18 inches of existing soils should be scarified, properly moisture conditioned, and compacted to a minimum of 90 percent of the maximum density as determined by ASTM Test Method D1557, If import fills are required to achieve the appropriate final grades, they should be placed as Engineered Fill. Engineered Fill should be placed in 6 to 8-inch loose lifts, properly moisture conditioned, and compacted to a minimum of 90 percent of the maximum density as determined by ASTM Test Method D1557. The upper soils, during wet winter months, become very moist due to the absorption characteristics of the soil. Earthwork operations performed during winter months may encounter very moist unstable soils, which may require removal to grade a stable building foundation. Project site winterization consisting of placement of aggregate base and protecting exposed soils during the construction phase r should be performed. Excavations, depressions, or soft and pliant areas extending below planned finished subgrade levels should be cleaned to firm, undisturbed soil and backfilled with Engineered Fill. Any buried structures encountered during construction should be properly removed and backfilled. In general, any septic tanks,_ debris pits cesspools or srml ar structures should be entirely removed. Concrete footings should be removed to an equivalent depth of at least 3 feet below proposed footing elevations or as recommended by the Soils Engineer. Any other buried structures should be removed in accordance with the recommendations of the Soils Engineer. Resulting excavations should be backfilled with Engineered Fill. '— 1417 No.Market Blvd.,Suite 1 • Sacramento,CA 95834 • (916)568-5858 • Fax: (916)568-5813