5700 23RD DR W 2018-06-28 - Laserfiche WebLink

November 29,2016 Project No.T-5922-6 Accordingly,temporary excavations in Type C soils should be laid back from the toe to the crest of the slope at an inclination of 1.5:1 or flatter. Temporary excavation side slopes in Type B soil can be laid back at an inclination of 1`:1. All temporary exposed slopes on excavations that will remain open for an extended time period should be covered with a durable reinforced plastic membrane during construction to prevent slope raveling and rutting during periods of precipitation. Excavations that expose perched or pockets of light seepage can likely be dewatered by conventional sump- pumping procedures along with a system of collection trenches. Excavations within the advance sands such as found in Test Pit TP-3 may require dewatering by well points in order to maintain relatively dry working conditions. This 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. Permanent Slopes We anticipate restoration of slopes adjacent to patio and retaining wall construction will match the current 3:1 (H:V) inclination of the existing slopes. In any case, 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. 5.4 Foundation Support The building may be supported on conventional spread footing foundations bearing on subgrades prepared as recommended in Section 5.2 of this report. Perimeter foundations exposed to the weather should bear at a minimum depth of 1.5 feet below the final exterior grades for frost protection. Interior foundations can be constructed at any convenient depth below the floor elevation. Footings bearing on the medium dense,inorganic silty sand fills, dense outwash sands,or competent structural fill overlying these soils can be dimensioned for an allowable bearing capacity of 2,500 pounds per square foot(psf). For short-term transitory loading such as wind and seismic, a one-third increase in this allowable capacity can be used. With structural loading as anticipated and this bearing stress applied, we estimate total foundation settlement would be less than one-half inch. • Page No. 7