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Mr. Mark Castano, P.E. February 21, 2024 <br />Keith & Associates, Inc. . Page 7 <br />Geotechnical Study – Intra Coastal Sports Complex – 15800 Collins Avenue NV5 Project No.: 17990 <br /> <br />CONSTRUCTION QUALITY ASSURANCE - INFRASTRUCTURE - ENERGY - PROGRAM MANAGEMENT - ENVIRONMENTAL <br />After preparation as described above, areas for structures that will have pavements on grade <br />should be proof-rolled. Proof-rolling should include planned development footprints plus a <br />five-foot perimeter. The densification should be observed by NV5 to identify and mitigate any <br />weak subgrade conditions evidenced by yielding or rutting at the wheels of the compactor. <br /> <br />2. New structural fill should consist of either inorganic, non-plastic sand having less than 10 <br />percent material passing the No. 200 sieve, or crushed limestone with a maximum rock size <br />of six (6) inches. In particular, fill soils placed within the upper 12 inches of the subgrade of <br />building slabs on grade should consist of either sand with less than 10 percent passing the <br />number 200 sieve, or crushed limestone with a maximum particle size of three (3) inches. <br /> <br />Based on our boring data, Layer 1 that consist of clean sands and limestone fragments <br />should satisfy the fill criteria. The materials might require localized sorting and moisture- <br />conditioning prior to re-use. Topsoil, organics, silt and peat should not be used as structural <br />fill. In any event, representative samples of the fill soils should be collected for classification <br />and compaction testing. The maximum dry density, optimum moisture content, gradation, <br />and plasticity should be determined. These tests are needed for quality control of the <br />compacted fill. <br /> <br />3. Fill soils should be placed with loose lift thicknesses of not more than 12-inches, moisture- <br />conditioned to within two (2) percent of the optimum moisture content based on ASTM D- <br />1557, and compacted to a minimum 95 percent relative compaction1. One test should be <br />performed for each 2,500 square feet of proof rolling and fill area per lift of fill soils. If during <br />the compaction process, the fill shows evidence of yielding under the weight of the <br />compactor, it should be removed and replaced with dry granular fill described above. Fill <br />particles exceeding one (1) inch in size should not be allowed to nest within the fill. <br /> <br />4. The vibrations produced by the operation of the roller/compactor should be monitored for <br />potential adverse effect on adjacent existing structures, pavements, and utilities. If existing <br />foundations and nearby structures will be affected by the vibration of the compactor, the <br />compaction procedure may require modification as approved by NV5. <br /> <br />7.2 FOUNDATION SUPPORT <br /> <br />7.2.1 ACIP <br />1. Our recommended tip elevation, allowable pile axial capacities, and grout strength for <br />foundation support are presented in the table below. <br /> <br />TABLE 3 - SUMMARY OF ACIP PILE ALLOWABLE CAPACITIES <br />Pile <br />Diameter <br />(in) <br />Minimum <br />Pile Tip <br />Elevation <br />(ft. NGVD) <br />Allowable <br />Compression <br />(kips) <br />Allowable <br />Tension <br />(kips) <br />Allowable <br />Lateral Load <br />(kips) <br />Minimum <br />Grout <br />Strength <br />(ksi) <br />14 -24 80 40 4 5 <br />Notes: <br />i. Minimum pile tip elevation based on the assumed site grade of +6 feet NGVD at the time of the borings. <br />ii. Required grout strength is for a 28-day test. <br />iii. Allowable lateral load is for lateral movement ½ to 3/8 inch. <br /> <br /> <br />1 Relative compaction refers to the in-place dry unit weight of a material expressed as a percentage of the maximum dry unit weight of the <br />same material as determined in the laboratory using the Modified Proctor procedure (ASTM D1557).