INVITATION TO BID 24-07-01 CONSTRUCTION OF INTRACOASTAL SPORTS PARK

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Mr. Mark Castano, P.E. February 21, 2024 Keith & Associates, Inc. . Page 8 Geotechnical Study – Intra Coastal Sports Complex – 15800 Collins Avenue NV5 Project No.: 17990 CONSTRUCTION QUALITY ASSURANCE - INFRASTRUCTURE - ENERGY - PROGRAM MANAGEMENT - ENVIRONMENTAL 2. For computer structural modeling of the building, an initial vertical spring constant of 80 kips per inch (kpi) may be used for the 14-inch-diameter piles. The vertical spring constant is the working pile load divided by the estimated pile settlement and is based on our experience and a review of available pile load test data in similar subsurface conditions. The initial spring constant value should be refined as the structural model is developed. The design value used should match the settlement estimates. 3. To evaluate the lateral capacity of the piles, we performed lateral load analyses using the LPILE computer program to estimate the performance of the piles under lateral loading. In the analyses, we have considered the simultaneous application of about 25 percent of the compression loads along with the lateral loads in Table 3 above. A fixed head condition was assumed for the pile. Modification factors of 0.4 and 1 respectively were applied to p-y soil resistance values to consider the effect of pile grouping since the LPILE program analyzes a single-pile condition only. Our recommendations for allowable pile lateral capacities for the fixed head condition are presented in Table 4 below. TABLE 4 - SUMMARY OF PILE LATERAL LOADS AND BENDING MOMENTS Pile Diameter (in) Allowable Lateral Load (kips) Maximum Bending Moment (in-kips) Depth to Maximum Moment (ft.) Depth to Zero Moment (ft.) 14 4 190 0 28 Notes: i. Lateral load capacities based on maximum pile head movement of ¼ to 3/8 inch. ii. Bending moments listed above are un-factored. iii. The depths in table above referenced to the bottom of pile cap/top of pile. The recommended pile lateral capacities assume that the piles and their caps can safely tolerate horizontal deflections on the order of ¼ to 3/8 inch. If required, we can provide higher lateral capacities associated with batter piles or with vertical piles where larger horizontal pile head deflections are allowed. The pile lateral resistance can be assumed to act at the base of the pile cap. 4. Resistance to lateral loads can be provided also by passive pressure acting on the pile caps and grade beams. However, this lateral resistance mode should not be used in conjunction with the lateral resistance as the larger deflections required to mobilize the passive resistance on foundation elements might not be consistent with those used for the pile lateral capacities presented above. Equivalent fluid densities of 180 and 80 pounds per cubic foot may be used to compute the passive pressures acting against the sides of the pile caps and grade beams above and below the groundwater table respectively. Passive resistance of the upper one foot of soil should be neglected, unless it is confined by a slab or pavement. Frictional resistance between the soil and bottom foundation elements should be ignored. The above values include a factor of safety of at least 1.5. 5. Pile reinforcing should be designed by the structural engineer to resist the tension and lateral forces applied to the pile systems. We recommend that piles resisting tension loads be reinforced over their entire length. The information provided in Table 4 above should be used to design the reinforcing for piles resisting lateral loads. If the pile is not reinforced over the entire length, we recommend as a minimum, a single No. 7 bar be installed the full length of the pile to verify pile cross-section continuity.