3315 BROADWAY 2017 HOPEWORKS STATION 2 Geotech Report 2022-10-25

HopeWorks Social Enterprises JN 17298 July 12, 2017 Page 2 The ground surface of the adjacent parcel to the south (Tax No. 00439079600700) is approximately 4 feet higher than those to the north and south. Thus, a 6-foot rockery borders the western end of this parcel, offset 8 feet from the western property line. A 9.5-foot-tall ecology block wall borders the western end of the next adjacent parcel to the south (Tax No. 00439079600900). This wall is battered, the toe is embedded one foot below the parking lot surface, and has little to no offset from the western property line. The wall also returns along approximately one third to one half of the parcel width, retaining the ground surface of the higher parking lot to the north. Finally, the southern-most parking lot is located on the northern half of the southern parcel (Tax No. 00439079601100); as discussed above, the southern half of this parcel contains the existing adjacent HopeWorks building. A 10.5-foot-tall, cast-in-place, concrete, retaining wall extends north from the western end of the existing building and borders the western end of the parking lot. The concrete retaining wall is offset 8.5 feet from the western property line. The subject site is bordered to the south by the existing HopeWorks building and to the north by a property containing a YWCA building. The existing one-story HopeWorks building overlies a full basement with an finished floor elevation of 70.8 feet that daylights to the north and east. The YWCA building has one story overlying a daylight basement and is located on the western 40 feet of the parcel. The provided topographic map indicates the YWCA building is offset 0.59 to 0.65 feet from the subject site. Based on our observations during our recent site visit, the YWCA building appears to have a lowest finished floor near an elevation of 76 feet. A parking lot covers the remainder of the parcel which slopes down from 76 feet along the building down to the alley to the east near elevation 68 feet. As discussed above, an ecology block wall follows the subject site's northern property line, retaining the YWCA building 9-id parking lot. SUBSURFACE The subsurface conditions were explored by drilling five test borings at the approximate locations shown on the Site Exploration Plan, Plate 2. Our exploration program was based on the proposed construction, anticipated subsurface conditions and those encountered during exploration, and the scope of work outlined in our proposal. The test borings were drilled on June 16, 2017 using a small track-mounted, hollow-stem auger drill. Samples were taken at approximate 2.5- to 5-foot intervals with a standard penetration sampler. This split-spoon sampler, which has a 2-inch outside diameter, is driven into the soil with a 140-pound hammer falling 30 inches. The number of blows required to advance the sampler a given distance is an indication of the soil density or consistency. A geotechnical engineer from our staff observed the drilling process, logged the test borings, and obtained representative samples of the soil encountered. The Test Boring Logs are attached as Plates 3 through 7. Soil Conditions Along the eastern property line, Test Borings 3 and 5 encountered medium-dense native silt at a depth of approximate 2.5 feet beneath a thin layer of loose fill. Dense to very dense slightly silty sand was exposed below 10 feet to the maximum-explored depth of 16.5 feet. Near the center of the subject site, Test Boring 4 encountered medium-dense native silt at approximately 5 feet below loose fill and native sand. Very dense slightly silty sand was encountered below 7.5 feet GEOTECH CONSULTANTS,INC.