SHI Builders West Orange NJ Prelim GI SWM Report 1

following removal of deeper topsoil and root mat layers. Difficult Excavation and Rock Excavation: Weathered rock/rock was encountered at depths as shallow as approximately 2.3 feet below existing site grades. In addition, difficult excavation was encountered apparent cobbles/boulders within the test pits. As such, depending on the final site grading plans, Dynamic Earth anticipates removal of weathered rock/rock and/or oversized materials will be required within excavations for the proposed buildings and/or utility installation. Conventional excavation equipment with rock ripping tools may be effective to remove only the uppermost weathered rock and/or rock. The speed and ease of excavation will depend on the type of grading equipment, the skill of the equipment operators, and the structure of the material itself. Planned excavation depths beyond refusal depths will likely require pneumatic hammers to remove the rock. Surface Preparation/Proofrolling: Prior to placing any fill or subbase materials to raise or restore grades to the desired building pad or pavement subgrade elevations, the existing exposed soils should be compacted to a firm and unyielding surface with several passes in two perpendicular directions with a minimum 10-ton vibratory, smooth drum roller during favorable moisture conditions. The drum roller should be operated in the static mode or a kneading “sheepsfoot” roller should be used where fine-grained soils are encountered at the subgrade elevation and/or where groundwater is suspected near subgrade elevations. The surface then should be proofrolled with a loaded tandem axle truck in the presence of Dynamic Earth to help identify soft or loose pockets which may require removal and replacement or further investigation. Dynamic Earth anticipates at least partial overexcavation if the subgrade is wetted or subjected to repeated construction traffic. Any fill or backfill should be placed and compacted in accordance with Section 5.3. Subgrade Protection and Inspection: Portions of the on-site soils are considered to be extremely moisture sensitive and every effort should be made to minimize disturbance of the on-site soils by construction traffic and surface runoff. These materials will likely become unsuitable if exposed to moisture and/or construction traffic. If the onsite soils become overly wetted, increased handling such as

ction traffic and surface runoff. These materials will likely become unsuitable if exposed to moisture and/or construction traffic. If the onsite soils become overly wetted, increased handling such as discing and drying during extended periods of favorable weather and/or subgrade stabilization may be required. Common stabilization for marginally unsuitable subgrades includes installation of geogrid (such as Tensar TX-5 of TX-7), mixing with granular soils and or chemical stabilization (lime or cement mixing). If required, the subgrade stabilization should be reviewed by the geotechnical engineer during construction. Dynamic Earth should be retained as the Geotechnical Engineer of Record to inspect soil conditions during construction and verify the suitability of prepared foundation, floor slab and pavement subgrades for support of design loads. SHI Builders 11 4266-99-001E