3301 SEAWAY BLVD Geotech Report 2022-10-25

• January 13,2016 Project No.T-7342 Accordingly, temporary excavations in Type C soils should have their slopes laid back at an inclination of 1.5:1 (Horizontal:Vertical)or flatter,from the toe to the crest of the slope. Side slopes in Type A soils can be laid back at a slope inclination of 0.75:1 or flatter. For temporary excavation slopes less than 8 feet in height in Type A soils, the lower 3.5 feet can be cut to a vertical condition, with a 0.75:1 slope graded above. For temporary excavation slopes greater than 8 feet in height up to a maximum height of 12 feet, the slope above the 3.5-foot vertical portion will need to be laid back at a minimum slope inclination of 1:1. No vertical cut with a backslope immediately above is allowed for excavation depths that exceed 12 feet. In this case, a four-foot vertical cut with an equivalent horizontal bench to the cut slope toe is required. All exposed temporary slope faces that will remain open for an extended period of time should be covered with a durable reinforced plastic membrane during construction to prevent slope raveling and rutting during periods of precipitation. The above information is provided solely for the benefit of the owner and other design consultants, and should not be construed to imply that Terra Associates, Inc. assumes responsibility for job site safety. It is understood that job site safety is the sole responsibility of the project contractor. 5.4 Slopes and Embankments All permanent cut and fill slopes should be graded with a finished inclination of no greater than 2:1. Upon completion of grading,the slope face should be appropriately vegetated or provided with other physical means to guard against erosion. Final grades at the top of the slope must promote surface drainage away from the slope crest. Water must not be allowed to flow uncontrolled over the slope face. If surface runoff must be directed towards the slope, the runoff should be controlled at the top of the slope, piped in a closed conduit installed on the slope face,and taken to an appropriate point of discharge beyond the toe. All fill placed for embankment construction should meet the structural fill requirements in Section 4.2 of this report. In addition, if the new fills will be placed over existing slopes of 20 percent or greater,the structural fill should be keyed and benched into competent native soils. Figure 3 presents a typical slope key and bench configuration. At minimum, a toe drain should be installed in the key cut as shown on Figure 3. Depending on seepage conditions, drains may also be required along individual benches excavated on the slope face. The need for drains along the upper benches will be best determined in the field at the time of construction. 5.5 Foundations The buildings may be supported on conventional spread foundations bearing on properly prepared subgrades of competent native soil or structural fills placed above competent native soils. Foundation subgrades should be prepared as recommended in Section 5.2 of this report. Perimeter foundations exposed to the weather should be a minimum depth of 18 inches below final exterior grades. Interior foundations can be constructed at any convenient depth below the floor slab. Page No. 10