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North County Library Addition Geotechnical Exploration Report 1001 County Road #512, Sebastian, Florida April 24, 2020 GFA Project No. 20-9197.00 Page 8 of 10 3.3 Vibration Monitoring Using vibratory compaction equipment at this site may disturb the adjacent library building and other nearby structures. Therefore, GFA recommends that these structures be monitored both before and during compaction operations. A proposal for providing vibration monitoring services during earthwork construction will be provided upon request. 3.4 Design of Footings A foundation system for any structure must be designed to resist bearing capacity failures, have settlements that are tolerable, and resist the environmental forces that the foundation may be subjected to over the life of the structure. The soil bearing capacity is the soil's ability to support loads without plunging into the soil profile. Bearing capacity failures are analogous to shear failures in structural design and are usually sudden and catastrophic. Based on the results of the soil borings performed at the site, GFA recommends the structure foundations be designed using a maximum allowable soil bearing pressure of 2,500 psf. Shallow foundations should be embedded a minimum of 12 inches below final grade measured from the lowest adjacent grade. Isolated column footings should be at least 24 inches in width. Continuous strip footings should have a width of at least 16 inches regardless of contact pressure. Once site preparation has been performed in accordance with the recommendations described in this report, the soils should readily support the proposed structure bearing upon a properly designed and constructed shallow foundation system. Footings and columns should be structurally separated from the ground floor slab, as they will be loaded differently and at different times, unless a monolithic slab foundation is designed. 3.5 Settlement Estimates Post construction settlements of the structure will be influenced by several interrelated factors, including (1) subsurface soil stratification and the strength/compressibility characteristics, (2) footing size, bearing level, applied loads, and resulting bearing pressure beneath the footings, and (3) the site preparation and earthwork construction techniques used by the contractor. Our settlement estimates for the proposed construction are based on the use of the site preparation and earthwork construction methods as recommended in this report. Any deviation from these recommendations could result in an increase in the estimated post -construction settlements of the proposed construction. We expect the majority of settlement to occur in an elastic manner and fairly rapidly during construction. Using the recommended maximum bearing pressure, the assumed maximum structural loads, and the field test data that we have correlated geotechnical strength and compressibility characteristics of the subsurface soils, we estimate that total settlements of the structure could be on the order of one (1) inch or less. Gr/