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

GEOTECHNICAL ENGINEERING STUDY Mr. Arthur Skotdal E-6225 _ c/o Dykeman Architects Pa9e s I Juiy 27, 1993 , a illar break consisting of a minimum of four inches � The slab should be provided with a c p y of free-draining sand or gravel. In areas where siab moisture is undesirable, a vapor barrier such as a 6-mil plastic membrane may be placed beneath the slab. Two inches of _ damp sand may be placed over the membrane for protection during construction and to aid in curing of the concrete. -i Fo�mdation Walls Below grade foundation walls must be designed to resist lateral earth pressures imposed ! by the retained soils. ' Walls that are designed to yield 0.001H, where H equals the height of the wall, can be 'I � designed to resist the tateral earth pressures imposed by an equivalent fluid with a unit weight of thirty-five l35) pcf. If wails are to be restrained at the top from free movement, o fift (50) cf. These values are based I id wei ht should be increased t y P the equioalent f u 9 -� on horizontal backfill and that surcharges due to backfili slopes, hydrostatic pressures, � traffic, structural loads or other surcharge loads will not act on the wall. If such surcharges are to apply, they should be added to the above design lateral pressure. ' i ' For earthquake loading, a rectangular pressure distribution equal to six times the wall f I height (6H) should be added to the above lateral earth pressure distribution. Foundation walls shouid be backfilled with a free draining ri�aterial conforming to the I WSDOT specification for grave� backfill for walis (WSDOT �-03.1212t1� Please refer to the �'ypical retaining Wall Drainage and Backfill detail presented on Plate 3. The free , draining material should extend at least eighteen (18) inches behind the wall. The �' " remainder of the backfill should consist of structural fill. A perfarated drain pipe should � l be placed at the base of the wall. Drain pipes should be surrounded by a soil that � functions as a filter in order to reduce the potential for clogging. Drain pipes located in t, I the free-draining backfill soil should be perforated with holes less than 1/4 inch in � diameter. The drain pipe should be surrounded by a minimum of one cubic foot per lineal � � , — foot with 3/8 inch pea gravel. I` I I _ � I � , , � �'� � ', �� d : � ~ Earth Consultants, Inc. j I . � i .-- � 1 , ,-a'',. ,:-,: �Y� -' ��,�.x._ ' _. - , . . . . . , � . � ; r.� ',� � � - i. � - . . . - .. - ' _ , _ _ . - . . . . . - . . . ''; . r� - � - - - . _ .- . . � . :.Cys T '.",-.'"7 rvt..' _ � - . . _ . .. , � . _