17 E MARINE VIEW DR 2019 Geotech Report 2025-10-01

Settlement Provided the footings are supported on at least 2 feet of properly compacted structural fill and that the building footprint has been preloaded/surcharged, we estimate the post construction total settlement of lightly-loaded shallow foundations will be on the order of about 1 inch. Loose or disturbed soils not removed from the footing excavation prior to placing concrete will result in additional settlement. We recommend that the footing excavations be cut using a smooth-edged bucket to reduce the amount of disturbed soil exposed at the subgrade, or the disturbed subgrade soil be thoroughly compacted prior to placing the structural fill. Lateral Resistance Lateral foundation loads may be resisted by passive resistance on the sides of footings and by friction on the base of the footings. For footings supported on structural fill placed and compacted in accordance with our recommendations, the allowable frictional resistance may be computed using a coefficient of friction of 0.35 applied to vertical dead-load forces. The allowable passive resistance may be computed using an equivalent fluid density of 300 pounds per cubic foot(pcf)(triangular distribution).The structural fill should extend out from the face of the foundation element for a distance equal to at least three times the depth of the element. The above coefficient of friction and passive equivalent fluid density values incorporate a factor of safety of 1.5. Footing Drains As currently envisioned,structures with interior space requiring protection from moisture with footing drains are not planned for the site. If these types of structures are constructed, we recommend that perimeter footing drains be installed.GeoEngineers can provide footing drain recommendations if needed. Pavement Subgrade Preparation New pavement sections must be installed over a dense and unyielding subgrade.Structural fill to establish subgrade elevation in pavement areas should be compacted to a minimum of 95 percent of its maximum dry density(MDD), as determined using test method ASTM D 1557. Prior to the placement of base course materials,the exposed subgrade should be proof rolled.Proof rolling should be accomplished with a loaded dump truck,large self-propelled vibrating roller,or equivalent piece of equipment.The purpose of this effort is to identify possible loose or soft soil and recompact disturbed areas of subgrade. Proof rolling should be carefully observed by qualified geotechnical personnel.Areas exhibiting significant deflection, pumping, or saturated soils that cannot be readily compacted should be over excavated to firm soil.Over excavated areas should be backfilled with compacted granular fill. During periods of wet weather, proof rolling could damage the exposed subgrade.Under these conditions,qualified geotechnical personnel should observe subgrade conditions to determine if proof rolling is feasible. Storm Water Detention Vault The development of the Delta site soil remediation facility(Phase 1)includes a proposed below-grade water storage vault on the north side of the property. We understand that the bottom elevation of excavation for the vault will be above the groundwater table(about Elevation 10 feet)and can be accomplished by cutting temporary slopes.If the vault extends below the high water table,it should be designed to resist hydrostatic and buoyant groundwater forces. GMENGINEERS� August3,2018 Page I1 File No.0643.015-00