Geotech Report 04 19 2021

SOR CONSULTING ENGINEERS, INC. Garden Homes Report No. 21-C-12 Proposed Residential Development Page 8 West Orange, NJ of fines into the fragments. The need for the placement of a geotextile fabric should be determined in the field at the time of construction. All structural fill and backfill placed within building areas should be installed under the technical observation of a geotechnical engineer. Controlled soil fill materials should be spread in layers on the order of 12 inches in loose thickness and compacted to at least 95 percent of maximum dry density as determined by the ASTM D-1557 test procedure. Layers of rock fill may be somewhat greater than 12 inches compatible with the appropriate compaction equipment and should also be compacted to a visually dense condition. Groundwater is not anticipated to present significant problems during construction. We recommend that surface grades be maintained during construction to prevent the inundation of the subgrade soils from surface water runoff. Any water seepage that may occur should be immediately collected and removed from the construction excavations by pumping from sumps established within or adjacent to excavations. All excavations should be in accordance with OSHA requirements. For this site, the soils are considered to be Type C which limits excavation sides to 1 vertical to 1% horizontal. Steeper slopes should be adequately protected with sheeting, shoring, and bracing. Permanent embankment slopes should be no steeper than 1 vertical to 3 horizontal for erosion control and maintenance purposes. Foundation Design Criteria: The proposed buildings may be supported on conventional spread foundations. Foundations may be supported directly on the controlled backfill, competent natural soils or clean %-inch size crushed stone placed over these materials or basalt bedrock. We recommend that the foundation subgrades be observed by a qualified geotechnical engineering firm to ensure that competent bearing soils are present and the subgrade should be recompacted or undercut as directed. The exposed foundation subgrade soils will likely consist of sandy silt/clayey silt, silty gravelly sand, or basalt bedrock. These sandy silt or clayey silt soils were in a soft condition and are susceptible to further disturbance during construction activities, especially in the presence of excess water. Care should be

ck. These sandy silt or clayey silt soils were in a soft condition and are susceptible to further disturbance during construction activities, especially in the presence of excess water. Care should be exercised during foundation excavation and construction to limit disturbance of the subgrade sails. If the exposed