11802 EVERGREEN WAY BASE FILE Geotech Report 2018-01-02 MF Import

B8/18/2005 15:27 4257478561 GEOTECH ' , PA(� 18 L��Ie Development, LLC August 16,2005 JN 05233 Page 9 instability. Please note that loose soil can cave suddenly and without waming, Excavatia�� foundadon, and utilRy conVactors shouid be made espedally aware of thls potential danger. These I'ecommendations may need to be modified if the erea nea�the potential cuts has been disturbed in the past by utility installation, or if settlement-sensitive uNlities are located nearby. All penitanerrt cuts lrrto native sofl should be inclined no steeper than 2.5:1 {H:�. To reduce the potential for shallow sloughing, fill must be compacted to the face of these slopes. Thls can t�e accomplished by overbuilding the ccn„paded fill and then qimming it bac9c to its final inclination. Adequate compaction of the slope face Is important for long-term stability and (s necessary to prevent excesslve settler.ient of patios, slabs, foundations, or ot�er improvements that may be placed near the edge of the slope. Water should not be allowed to flow uncoMrolled over the top of any temporary or permanent slope. All permanently exposed slopes should be seeded w(th an appropriate species of vegetatlon to reduce e�osion and improve the stability of the su�cia) layer of soll. DRqJNA6E CONSIDERATIONS We recommend that foundatian drains be installed at tFie base of all foundation and earth-retaining waps. These drains should be surrounded by at least 6 Inches of 1-lnch-minus, washed rock a�d then wrapped in non-woven, geotextile fiker fabric(Mirafi 140N, Supac 4NP, or similar mater(ah. At ks highest point, a perforated plpe invert should be at least 6 Inches below the bottom of a slab floor or the level of� crawl space, and it should be slopad for drainage. All roof anci Surface water drafns must 6e kept separatE from the foundation drain gystem, A typical drain detal fs attached to this report as Plate 12. For the best long-term performance, perfprated PVC pipe is recommended for all subsurtace drains. Groundwater was observed during our field work. If seepage Is encountered in an excavatlon, it shauld be drained from ihe sile by directi�g it tltrough drainage ditches, perforated pipe, or French drains, or by pumping it from sumps interconnected by shallow connector tnenches at the bottom of the excavation. The excavallon and site shoufd be graded so that su�face wator Is directed off the sRe and away from the tops of slopes, Weter ahould not be allowed to stand In any area where foundations, slabs, or pavements are to be constructerl. Final ;,ite grading fn areas adjacent to buildings should slope eway at least 2 percerrt, except where the area is paved. Surtace drelns should be provided where necessary to prevent pondfng of water behind foundation or retalning walls. PAVEMENTAREAS The pavement section may be supported on a minimum 1 foot o1 granular structut�21 f111 compaded to a minimum 95 percent density based on Modified Proctor (ASTM Test Desfgnation D-1557). Becauae the site sofls are silty and moisture sensitive, we reopmmend thet the pavement subgrade must be ln � stable, non-yielding condition at the time of paviny, Addfional granular structural fill and/or geotextile fabric may he needed to stabilize soft, wet, or unstable areas, To evaluate pavement subgrede strength, we recammend that a proof roll be completed with a !oaded dutnp truck immediately before paving. In m�st Instances where mstabfe subgrade cond'dions are encountered, an addkional 12 inches of granular structural fill will stab(lize the subgrade, except for very soft areas where additional fill could be required. The subgrade should be evaluated by GEOTECH CONSULTANTu,INC.