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 11 Geotechnical Study – Intra Coastal Sports Complex – 15800 Collins Avenue NV5 Project No.: 17990 CONSTRUCTION QUALITY ASSURANCE - INFRASTRUCTURE - ENERGY - PROGRAM MANAGEMENT - ENVIRONMENTAL 2. Slabs should be reinforced for the loads that they will sustain and construction joints should be provided at frequent intervals. 3. Slabs in contact with soil are subject to movement of moisture from the soil upward through the slab. To prevent such moisture vapor transmission, a moisture barrier should be placed on the slab subgrade, and should be protected from damage during construction. Construction joints should be provided with water stops in any permanently submerged areas. 7.4 EXCAVATION AND DEWATERING 1. Shallow excavations into the near-surface materials will likely stand vertical for short periods of time only. The excavation sides will unravel over time as they are exposed to weather and construction traffic. Localized weak sandy zones could become loose if unsupported. Deeper excavations, especially those that extend below the groundwater table, as well as excavations that will remain open for longer periods of time will require support in the form of temporary shoring or sliding trench boxes to prevent instability of excavation walls and to protect workers from injury. All excavations should comply with Occupational Safety and Health Administration (OSHA) design and safety requirements. Shoring designs should be signed and sealed by a Florida-licensed professional engineer, and should be provided for the Owner’s review. 2. Average groundwater elevation is expected to be approximately between Elevation 0 and +4 feet NGVD for this site. As stated above, groundwater levels outside this range could be encountered during construction. Dewatering for foundation excavations is not anticipated to be a significant factor for this project. Nonetheless, some dewatering could be required for installation of deeper foundations, and utilities and appurtenances. We judge that localized dewatering of foundation excavations can be accomplished using pumps and sumps. Dewatering of larger excavations and larger volumes such could require the installation of well points or other dewatering systems. It should be noted there are two components to the dewatering process. The first is extracting the water from the subsurface and the requirement of the project to maintain a dry excavation to allow construction to proceed. The other component is the ability to discharge the volume of water extracted. The contractor must ensure this capability exists for the site such that all dewatering and consequent effluent discharge will meet the requirements of the local jurisdictional agencies including Miami-Dade County, Florida Department of Environmental Protection (FDEP), Florida Department of Transportation, and South Florida Water Management District (SFWMD) as appropriate. This study did not include specific testing or analysis to determine if dewatering is feasible or if adequate discharge is available. Ultimately, dewatering of the site to facilitate construction is the contractor’s responsibility. During dewatering the adjacent properties must be monitored for adverse impacts from dewatering drawdown. The dewatering subcontractor should submit a proposed design for dewatering operations to the owner for review and approval prior to commencing work.