1310 SE EVERETT MALL WAY Geotech Report 2022-10-25

l ' Darden Restaurants, Inc. September 15, 2011 Proposed Olive Garden—Everett,Washington Page 7 of 12 Continuous wall and spread footings should be proportioned for an allowable bearing pressure of 2,500 psf. Continuous wall foundations should be at least 18 inches wide and isolated column footings should be at least 24 inches wide. The bottom of exterior footings should be at least 18 inches below the lowest adjacent final grade for frost considerations. The bottom of interior footings should be placed at least 12 inches below the bottom of the floor slab. Due to the presence of existing fill and the risk of potentially deeper fill soils in unexplored areas of the pad, we recommend that the continuous strip footings be reinforced with at least four No. 4 bars (2 top and 2 bottom). This recommended steel reinforcement is not intended to be used in lieu of that needed for structural considerations but is recommended due to the on-site soil conditions. The actual foundation design and steel reinforcement should be determined by the structural engineer. The recommended allowable bearing pressure applies to the total of dead plus long-term live loads. The allowable bearing pressure may be increased by one-third for short-term loads such as those resulting from wind or seismic forces. 3.5 Settlement We estimate that foundations designed and constructed in accordance with the recommendations herein will experience post-construction total settlements generally less than 1-inch with differential settlement along a 40-foot long portion of a continuous footing, or similarly spaced column footings generally less than '/2-inch. Total and differential settlements of these magnitudes are usually considered tolerable for the anticipated construction. However, the tolerance of the proposed structure to the predicted total and differential settlements should be confirmed by the structural engineer. 3.6 Floor Slabs The building floor slab may be supported by structural fill or competent native soil. A 4-inch- thick layer of imported granular material should be placed over the prepared subgrade to assist as a capillary break. A subgrade modulus of 150 pounds per cubic inch (pci) may be used to design the floor slab. Imported granular material should be crushed rock or crushed gravel and sand that is fairly well- graded between coarse and fine, contain no deleterious materials, have a maximum particle size of 1'/2 inches, and have less than 5 percent by weight passing the U.S. Standard No. 200 Sieve. The imported granular material should be placed in one lift and compacted to not less than 95 percent of the maximum dry density as determined by ASTM D698. Vapor retarders are often required by flooring manufacturers to protect flooring and flooring adhesives. Many flooring manufacturers will warrant their product only if a vapor retarder is installed according to their recommendations. However, vapor retarders can trap and hold excess moisture when installed in rainy weather. Selection and design of an appropriate vapor retarder, if needed, should be based on discussions among members of the design team. Vapor retarders should be installed in accordance with ACI 302.1, Chapter 3. The precautions listed below should be followed closely for construction of all slabs-on-grade. These details will not reduce the amount of movement, but are intended to reduce potential