3631 WETMORE AVE 2020-05-06 - Laserfiche WebLink

April 12,2018 Page 3of5 Retaining Wall Design We have designed the wall based on vertical wall construction. We recommend the following recommendations be incorporated into the construction of the wall: • We recommend using the Century style Keystone Blocks (8" tall by 12"wide). • If a cap block is used,it must be entirely above ground and as such will not be considered in the total height of the wall. • A minimum of 0.5 feet of toe embedment below the adjacent sidewalk grade is necessary for erosion protection and stability purposes. • A 6-inch thick layer of 5/8 inch minus or 1-1/4 inch minus crushed rock should be placed and compacted along the wall subgrade to provide a leveling course. • Geogrid reinforcement should consist of Miragrid 8XT, or an equivalent approved by us. • The soil used in the reinforcement zone must consist of structural fill as described in the General Wall Subgrade Preparation section of this report. • Density testing of structural fill should be performed per manufacturer's recommendations. At least one test per lift is typically recommended. Wall Design Wall calculations and design schematics are attached at the end of the report. The following geogrid schedule can be used to determine the appropriate geogrid length for the changes in the wall height: GEOGRID SCHEDULE EXPOSED WALL NO. OF GEOGRID GEOGRID LENGTH HEIGHT(FT.) LAYERS(Placed every 2 (FT.) blocks vertically) <3.5 0 - 3.5-4.5 1 3.2 4.5-6 2 5.2 6-7.5 3 6.2 Wall Drainage To guard against hydrostatic pressure development, drainage must be installed behind the wall. We recommend that wall drainage consist of a minimum 12 inches of clean 5/8 inch to 1 inch crushed rock with less than three percent fines placed against the back of