Geotechnical Engineering Report 12 10 2024 submission

Mavis Store #2296 December 10, 2024 ECS Project No. 44:2100 Page 8 4.2 FLOOR SLAB Provided subgrades and Structural Fills are prepared as discussed herein, proposed floor slabs can be constructed as ground-supported slabs (slab-on-grade). The floor slab can bear on Stratum I or Stratum II soils provided that the entire footprint of the slab is proofrolled (see Section 5.1.3) and compacted (see Section 5.1.4) prior to placing the Granular Capillary Break/Drainage Layer. It is important to have ECS observe the subgrade and proofrolling to confirm the soil conditions are as anticipated. Soft or yielding soils, or otherwise unsuitable materials may be encountered in some areas and should be removed and replaced with compacted Structural Fill in accordance with the recommendations included in this report. The following graphic depicts our ground-supported slab recommendations. Vapor Barrier Concrete Slab Granular Capillary Break/Drainage Layer Drainage Layer Thickness: 6 inches (minimum) Drainage Layer Material: ¾-inch clean, crushed stone Compacted Subgrade 95% modified Proctor maximum dry density (ASTM D1557) Figure 4.2.1 – Ground-supported Concrete Slab Subgrade Modulus: Provided the Structural Fill and Granular Capillary Break/Drainage Layer are constructed in accordance with our recommendations, floor slabs may be designed assuming a modulus of subgrade reaction, k1, of 85 pounds per cubic inch (pci). The modulus of subgrade reaction value is based on a 1-foot by 1-foot plate load test. Vapor Barrier: Before the placement of concrete, a vapor barrier may be placed on top of the Granular Capillary Break/Drainage Layer to provide additional protection against moisture penetration through the floor slab. When a vapor barrier is used, special attention should be given to surface curing of the slab to reduce the potential for uneven drying, curling and/or cracking of the slab.

on through the floor slab. When a vapor barrier is used, special attention should be given to surface curing of the slab to reduce the potential for uneven drying, curling and/or cracking of the slab. Depending on proposed flooring material types, the structural engineer and/or the architect may choose to eliminate the vapor barrier. Slab Isolation: Floor slabs should be isolated from the foundations and foundation-supported elements of the structure so that differential movement between the foundations and slab will not induce excessive shear and bending stresses in the floor slab. Where the structural configuration prevents the use of a free-floating slab such as in a drop-down footing/monolithic slab configuration, the slab should be designed with suitable reinforcement and load transfer devices to preclude overstressing of the slab. 4.3 SEISMIC DESIGN CONSIDERATIONS Seismic Site Classification: The 2021 International Building Code – New Jersey edition (2021 IBC-NJ), which references ASCE/SEI 7-16 – Minimum Design Loads and Associated Criteria for Buildings and Other Structures, requires site classification for seismic design based on the upper 100 feet of a soil profile. Our authorized scope of services for the project did not include a site-specific seismic Site Class determination (e.g., 100 -foot soil profile). Therefore, to determine the seismic Site Class using Section 4.5 of the 2024 New Jersey State Hazard Mitigation Plan was referenced. The statewide seismic Site Class map contained in Section 4.5 (Figure 4.5-3), indicates the appropriate seismic Site Class is “C.” The Site Class definition should not be confused with the Seismic Design Category designation, which the Structural Engineer typically assesses.