5109 SOUND AVE 2017-08-02 - Laserfiche WebLink

July 21, 2014 Two Single-Family residences L&A Job No. 14-065 Page 10 SITE PREPARATION AND GENERAL GRADING Vegetation within construction limits should be cleared and grubbed, while vegetation outside of construction areas should be protected and maintained. Loose topsoil, disturbed soil, and weak weathered soil should be completely stripped down to hard silt and/or medium-dense sand deposit within building pads of the proposed new residences. The exposed soils should be compacted to a non-yielding state with a vibratory compactor and proof-rolled with a piece of heavy earthv��ork equipment. EXCAVATION AND FILL SLOPES Under no circumstance should excavation slopes be steeper than the limits specified by local, state and federal safety regulations. Unsupported temporary cuts greater than 4 feet in height should be no steeper than 1H:1V in topsoil, disturbed soil, and weathered soil, no steeper than 3/4H:1 V in the medium-dense advance outwash sand soil, and no steeper than 1/2H:1V in the hard Whidbey formation silt soil. Permanent cut banks should be no steeper than 2-1/4H:1 V in topsoil, disturbed soil and weathered soil, and no steeper than 1-1/2H:1V in the underlying medium-dense advance outwash and hard silt soils. The soi] units and the stability of cut slopes should be observed and verified by a geotechnical engineer during excavation. Pernianent fill embankments required to support structural or traffic load should be constructed with compacted structural fill placed over undisturbed, proof-rolled, firm, native soil after the surficial unsuitable soils are completely stripped. Permanent fill to be placed over slopes steeper than 15 percent grade should be retained structurally. The exposed ground exceeding 20 percent grade should be benched with vertical steps not LIU & ASSOCIATES, INC.