Geotechnical Engineering Report 12 10 2024 submission

Mavis Store #2296 December 10, 2024 ECS Project No. 44:2100 Page 1 EXECUTIVE SUMMARY The following summarizes the main findings of the exploration, particularly those that may have a cost impact on the planned project. Further, our principal foundation recommendations are summarized. Information gleaned from the Executive Summary should not be utilized in lieu of reading the entire geotechnical engineering report. Based on the planned construction and subsurface conditions encountered, we believe it is technically feasible to support the new store building on conventional shallow foundations including column footings and continuous wall footings.  Project grading plans including the building’s proposed finished floor elevation (FFE) were not provided, therefore, we have assumed the finished floor is within 1 to 2 feet of existing grades. Once a grading plan is provided, it should be provided to ECS so we can review and confirm the recommendations included herein need to be changed/updated.  Considering the FFE assumption above, foundations may be proportioned assuming a net allowable bearing capacity of 3,000 pounds per square foot if the recommendations herein are followed.  Existing fill/Possible fill materials were observed within several of the borings. Existing fills (without documentation of proper placement) are not suitable for foundation support and will require removal under foundation elements, therefore, some undercutting during construction may be necessary.  Following proper site preparation techniques, we believe the foundations will be capable of supporting the indicated loading with the potential for total post-construction settlement of less than 1-inch and a differential settlement of less than 0.5-inch.  The floor slab can be designed as a ground-supported slab assuming a modulus of subgrade reaction, k1, of 85 pounds per cubic inch and our subgrade recommendations.  The recommended seismic Site Class for the project site location is “C.”  A Seasonally High Groundwater Table (SHWT)

1, of 85 pounds per cubic inch and our subgrade recommendations.  The recommended seismic Site Class for the project site location is “C.”  A Seasonally High Groundwater Table (SHWT) determination at the site was not included in the scope at this time.  We anticipate stormwater management (SWM) infiltration testing will be required at some point in the project lifecycle. During the exploration/testing for the SWM features, we believe it will be beneficial to perform additional test pits within the building footprint to further evaluate the existing fill materials and provide a better determination if these materials will be suitable for support of the foundations and/or if full or partial undercuts will be necessary. Please refer to the body of the report for further details on subsurface conditions encountered within the completed borings and for our specific geotechnical engineering recommendations for the project.