6807 EVERGREEN WAY 2016-01-01 MF Import

GEOTECHNICAL ENGINEERING STUDY JMD Architecture April 19, 1999 E-8689 Page 9 The appropriate locations of subsurface drains, if needed, should be established during grading operations by ECI's representative at which time the seepage areas, if present, may be more clearly defined. During construction, the site must be graded such that surface water is directed off the site. Water must not be allowed to stand in area where buildings, slabs or pavements are to be constructed. Loose surfaces should be sealed at night by compacting the surface to reduce the potential for moisture infiltration into the soils. Final site grades must allow for drainage away from the building foundations. The ground should be sloped at a gradient of tnree percent for a distance of at least ten feet away from the building, except in paved areas, which can be sloped at a gradient of two percent. Footing drains should be installed around the building perimeter, at or just below the invert of the footing, with a gradient sufficient to initiate flow. A typical detail is provided on Plate 3. Under no circumstances should roof downspout drain lines be connected to the footing drain system. Roof downspouts must be separately tightlined to discharge. Cleanouts should be installed at strategic locations to allow for periodic maintenance of the footing drain and downspout tightline systems. Utilitv Suoa�rt and Backfiil Based on the soil conditions encountered, the soils expected to be exposed by utility excavations should provide adequate support for utilities. Utility trench backfiil is a primary concern in reducing the potential for settlement along utility alignments, particularly in pavement areas. It is important that each section of utility line be adequately supported in the bedding materiai. 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 heavy compaction equipment is brought into use. The remainder of the trench backfill should be placed in lifts having a loose thickness of less than twelve inches. A typical trench backfill section and compaction requirements for load supporting and non-load supporting areas is presented on Plate 4. Existing utility pipes to be abandoned should be plugged or removed so that they do not provide a conduit for water and cause soil saturation and stability problems. Earth Can:ultant�, Inc.