3214 BROADWAY BROADWAY KINECT APARTMENTS 2021-08-11

• American Property Development ES-0599.06 • January 22, 2015 Page 12 • Updated June 9, 2016 • • Retaining Walls • • Retaining walls should be designed to resist earth pressures and any applicable surcharge • loads. For design of the garage level foundation walls, the previous earth pressure values • provided for cantilever and multiple tieback shoring walls should be used, as appropriate for yielding and restrained wall conditions. These earth pressure values were previously provided • in the Shoring Recommendations section of this study. With respect to site retaining walls • constructed independent of the building foundation walls at or near existing site grades, the • following values should be used for design: • Site Retaining Walls • • Active Earth Pressure (Yielding Wall) 35 pcf(equivalent fluid I granular fill) = • At-Rest Earth Pressure (Restrained Wall) 50 pcf • • • Traffic Surcharge (Passenger Vehicles) 70 psf(rectangular distribution) II • Passive Resistance 350 pcf(equivalent fluid) • • • Allowable Soil Bearing Capacity 4,000 psf (preliminary) • • • Coefficient of Friction 0.40 - Additional surcharge loading from foundations, sloped backfill, or other loading should be • included in the retaining wall design, as appropriate. Drainage should be provided behind • retaining walls such that hydrostatic pressures do not develop. If drainage is not provided, • hydrostatic pressures should be included in the wall design, as appropriate. The geotechnical engineer should review retaining wall designs to verify that appropriate earth pressure values • have been incorporated into the design and to provide additional recommendations, as • necessary. • Retaining walls should be backfilled with free draining material that extends along the height of • the wall, and a distance of at least 18 inches behind the wall. The upper one foot of the wall • backfill can consist of a less permeable (surface seal) soil, if desired. In lieu of free draining • backfill, use of an approved sheet drain material can also be considered, based on the • observed subsurface and groundwater conditions. The geotechnical engineer should review • conditions at the time of construction and provide recommendations for sheet drain, as appropriate. A perforated drain pipe should be placed along the base of the wall, and • connected to an appropriate discharge location. Where foundation walls are formed against the • temporary shoring walls, the shoring wall drainage illustrated on Plate 6 can be utilized. For , site retaining walls receiving backfill, the retaining wall and drainage detail illustrated on Plate 7 should be considered. • It • Earth Solutions NW,LLC • • •