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EAC Consulting, Inc. eacconsult.com City of Sunny Isles Beach • RFQ 19-11-01 • Professional Engineering and Architectural Services for Pedestrian Bridge with Park Elements Across A1A at 174th St. design phase, we will evaluate different structural systems for both the superstructure and substructure, along with the park themes and architectural features in close coordination with the City. Final design will be performed per the selected alternate by the City. The bridge typical section will include both landscaping and pedestrian zones separated by glass railings. The minimum width that we recommend for the pedestrian walkway zones are 12 feet but with additional space to add landscaping and seating and other amenities. We can also integrate pergolas to provide shade upon the City’s request. The elevated bridge park will include benches, planters, steps and ramps, bicycle racks, trash and recycle receptacles, railings, and aesthetic lighting. Foundations The EAC Project Team has reviewed all data available from various sources to determine the geotechnical approach and understanding. The presence of the variable subsurface conditions - coupled with a residential setting, high traffic volume and noise sensitive site - makes foundation design and construction extremely challenging for this project. Our approach considered all lessons-learned and our knowledge from recently constructed foundation construction projects. All required geotechnical services will be performed in accordance with FDOT’s current Soils and Foundation Handbook (2020) and specifications. Borings and rock coring will be required at each foundation location to confirm our advanced knowledge of subsurface conditions in the project area, specifically one SPT boring per pier/bent to obtain more comprehensive geotechnical information and to reduce risks of schedule and pile or drilled shaft overruns. The Project Team performed a preliminary evaluation of shallow and deep (driven piles and drilled shafts) foundation options. However, given the unfavorable near-surface subsurface conditions, spread footings are not feasible, and would result in very large dimensions - due to the relatively low soil bearing capacity and predicted excessive settlements of the underlying loose to very loose sandy soils. Drilled shafts are a feasible foundation system, and its construction uses relatively low vibration equipment; hence friendly to the surrounding environment and resulting in a smaller foundation footprint and less MOT requirements. The EAC Project Team will also explore the use of 24 inch diameter ACIP pile foundations for the bridge. The use of ACIP piles eliminates the risks of causing vibration-related damages - associated with pile driving during foundation construction - to existing structures. Most recently, FDOT has allowed the use of ACIP pile foundations for bridge structures; however, FDOT is presently in the process of preparing developmental specifications for the use of ACIP pile foundations for an on-going and upcoming vehicular bridge project in District 4. GEOSOL has gotten approval from the FDOT’s Central Office to use ACIP piles for the proposed pedestrian bridge connecting the existing Tri-Rail Station Pedestrian Bridge to the new parking structure at the Golden Glades Multimodal Transportation Facility. GEOSOL is also working as part of the FDOT Review Team for the I-395 project, and working with FDOT’s Central Office in the implementation of ACIP piles for support of segmental bridges and signature bridges. For the elevators and stairs, the EAC Project Team will use ACIP. ACIP piles have been successfully used on numerous transportation infrastructure projects in Miami-Dade County - including the City of Miami Beach West Avenue vehicular bridge over the Collins Canal, Miami-Dade Transit elevated guideway bridges, Miami International Airport (MIA) parking garages, MIA transportation hub, MIA vehicular bridges, and a 200-foot high air traffic control tower at the Miami-Opa-Locka Executive Airport. Also, in the private sector, Auger cast piles are commonly used in South Florida to support heavily loaded structures - such as high-rise condominium towers, hotels, and arenas. Pedestrian Bridge Railings One of the major objectives for this project is to avoid the use of a fence or cage over Collins Avenue - which is common in many pedestrian bridges in Florida. We will propose to use landscaping and a buffered area so that pedestrians are not walking adjacent to the roadways below. This will allow for a more natural and open bridge design. The proposed conceptual glass railings are a maintenance concern due to the salt derived from the proximity to the beach. During the preliminary design phase we will consider this alternative, however, we will also propose consideration of stainless-steel flexible mesh - which can be very transparent and would not require the cleaning and maintenance associated with glass. Elevators The proposed elevators will be designed and positioned in strategic locations that will not impact pedestrian circulation near and under the new pedestrian bridge. We will recommend the use of high resistant materials to minimize maintenance in the future. We have recently designed several pedestrian bridges with elevators and are acquainted with all the features required to extend longevity and reduce life cycle costs. Aesthetic Bridge Lighting The aesthetic lighting will enhance the appearance of the pedestrian bridge at night, and will provide a safer and more comfortable crossing. We will propose the use of low