2825 COLBY AVE COLBY CENTER Geotech Report 2018-01-02 MF Import

GEOTECHNICAL ENGINEERING STUDY Mr. Arthur Skotdai -� c/o Dykeman Architects E-6225 July 27, 1993 Page 12 - Utility trench backfill is a major concern in preventing settlement along utility alignments, particularly in pavement areas. It is important that each section of utility line be adequately supported in the bedding material. The material should be hand tamped to -� ensure support is provided around the pipe haunches. Fill should be carefully placed and hand tamped to about twelve inches above the crown of the pipe before any heavy compaction equipment is brought into use. The remainder of tlie trench backfill should - be placed in lifts having a loose thickness of less than twelvs inches. A typical trench backfiil section and compaction requirements for load supporting and non-load supporting areas is presented on Plate 5. Pavement Areas ' The adequacy of site pavements is related in part to the condition of the underlying � subgrad�. To provide a properly prepared subgrade far pavements, we recommend the subgrade be treated and prepared as described in the Site Preparation and General � Earthwork section of th�s report. This mea�s at least the top twelve (12) inches of the ' subgrade should be cornpacted to 95 percent of the maximum dry density (per ASTM D- , 1557-78). It is possibie that some localized areas of soft, wet or unstable subgrade may I still exisi after this process. Therefore, a greater thickness of structural fill or crushed rock may be needed to stabilize these localized areas. The following pavement sections � are recommended parking and driveway areas: � • Two inches of asphalt concrete fAC) over four inches of crushed rock base (CRB) , material, or I � Two inches of AC over two inches of asphalt treated base (ATB} material. I � LIMITATIORS I Our recommendations and conclusions are based an the site materiais observed,selective laboratory testing and engineering analyses, the design information provided us by Dykeman Architects, and our experience and engineeringjudgement. The conclusions and � recommendations are professional opinions derived in a manner consistent with that level of care and skill ordinarily exerc;sed by other members of the profession curren�,ly practicing under sirriilar conditioi�s in this area. No warranty is expressed or implied. I I IEarth Consultants, Inc.