3003 W CASINO RD BLDG 45-12 2016-10-20

777X Static Test Building I 7 Table 4 - Coefficient of Subgrade Reaction Ks Bearing Soil Unit (psi) Very dense,very silty sand(Glacial Till) 100 Imported Structural Fill over Glacial Till 65 2 Feet of Imported Structural Fill over Medium dense,silty sand(Native Soils and 60 Fill)over Glacial Till Note: pci =pounds per cubic inch Retaining Structures We understand that in order to minimize the impact on the adjacent roads, retaining walls will be constructed in the south and east portions of the site. These will be constructed as soldier pile walls. In general,the solider piles and base of the excavation will be located within the glacial till (bearing) layer on the eastern portion of the site. In the southwest corner of the site,the bearing layer drops to an elevation of 545 feet. In this area,the glacial till bearing layer is much deeper,and the soils above the till have soft layers present. Design for the south retaining wall must take into account bearing layer elevations included on Figure 2. Lateral Earth Pressures If no utilities are located in the zone of deformation,the wall may be designed using active earth pressures. If settlement-sensitive structures or utilities exist within the potential zone of deformation or if the wall system is too stiff to allow sufficient lateral movement to develop an active condition, at-rest earth pressures should be used to design the wall. Theoretically, little movement should occur behind walls properly designed and installed for at-rest conditions. The following recommendations apply to permanent building walls where drainage is provided behind the wall to prevent hydrostatic pressure buildup. Figure 3 presents our recommend earth pressures for permanent cantilevered soldier pile walls. Yielding walls are defined as those for which allowable deflection is more than 0.001 times the height of the wall (i.e., 1/8 inch for a 10 foot high wall). Lower passive pressures are necessary for the area in the southwest corner where the bearing layer is deeper and below the below the water table. Bearing layer elevations and approximate contours are provided on Figure 2 and should be used to determine what passive pressure to use at individual soldier pile locations. Footings, material stockpiles,or other large loads that are behind and adjacent to subgrade walls will impose additional lateral loads on the walls. We recommend using the surcharge pressures on Figure 4 for these loads. s� 19106-01 HAffO WSL-R May 29,2015