Harborwalks and Boardwalks

Al Bennett Fishing Pier Replacement

gzadan — Thu, 27 Aug 2020 18:33:21 +0000

Al Bennett Fishing Pier Replacement gzadan Thu, 08/27/2020 - 14:33

Challenge

On August 28, 2011, Tropical Storm Irene came ashore along coastal Connecticut, causing severe damage to coastal areas. City of Bridgeport鈥檚 Seaside Park sustained severe damage as a result of wave action, flooding and erosion. Included in the park鈥檚 devastation was the Al Bennett Fishing Pier as storm surge had caused severe structural damage making the pier unsafe. The pier, located at the westernmost area of Seaside Park at the entrance to Black Rock Harbor, had been dedicated in 1976 as the Albert Bennett Fishing Pier to honor a local fishing enthusiast and editor for the Bridgeport Post newspaper. While the City was awaiting disaster recovery funding approval from FEMA and the State, Superstorm Sandy destroyed what remained of the pier鈥檚 superstructure, leaving only the timber piles and pile caps. The design and construction project required compliance with two separate disaster recovery grants and required a 25% matching contribution from the City.

Solution

The City retained GZA as one of three on-call coastal engineering firms in 2015. GZA then bid against the other on-call firms and was retained to design and develop FEMA-compliant construction bid plans and specifications for rebuilding of this very popular fishing and pedestrian pier. The FEMA grant required GZA to design the pier to its pre-disaster dimensions and use. The original pier was a 12-foot-wide by 175-foot-long timber pier that was supported on twenty-four 12-inch diameter timber piles. The piles were arranged in twelve 2 pile bents spaced approximately 15鈥�-7鈥� on-centers. As a result of the two storms, most of the structure was destroyed, and GZA determined what remained was unsafe for use. GZA designed a new pier with new foundations and superstructure. A Contractor was selected in 2017 and construction was completed in 2018, requiring costs to be allocated to two separate disaster recovery grants.

Benefit

The popular facility was fully restored to its original size and function for recreational use by Bridgeport residents, fishing enthusiasts, and visitors.

Assisted in securing funding under FEMA Public Assistance Disaster Recovery Grant Program
Design of new drilled pile foundations and decking structure
Contract compliance with multiple State of CT Agencies and FEMA requirements
Resilient design of a popular community amenity

Water

Waterfront and Coastal Engineering

Silver Sands State Park and Walnut Beach Boardwalks

gzadan — Thu, 11 Jun 2020 13:07:54 +0000

Silver Sands State Park and Walnut Beach Boardwalks gzadan Thu, 06/11/2020 - 09:07

Challenge

The State of Connecticut Department of Construction Services and Department of Energy and Environmental Protection (CTDEEP) approved funding for design and construction of an extension of an existing boardwalk at Silver Sands State Park as well as the construction of a new boardwalk at Walnut Beach in Milford. The boardwalk needed to cross two creeks, comply with wetlands regulations and the endangered species act due to a piping plover habitat, comply with ADA regulations for beach access, and be designed to support the weight of vehicular traffic for Parks Department personnel and withstand coastal flooding.

Solution

GZA completed subsurface explorations, geotechnical engineering and the structural design. Synthetic decking is designed along the entire boardwalk length of 3800 feet. As part of GZA鈥檚 engineering effort, coastal processes analysis was completed by a coastal geologist, and the alignment was adjusted where possible to reflect a receding shoreline and provide recreational value for park visitors.

Benefit

The timber-framed, pile-supported boardwalk with 15-foot spans of recycled decking materials features two 25-foot wide creek crossings, viewing deck areas, and ADA-accessible beach access ramps. The boardwalk is the longest in the state and designed to support 3000 lbs. gross vehicle weight for maintenance and emergency access only) operated by the Parks department. Railings and/or curbs were designed along the boardwalk depending on the height of the boardwalk above the beach. Three at-grade, cast-in-place concrete ramps allow beach access for heavier emergency vehicles such as an ambulances or fire apparatus.

Subsurface explorations in regulated areas of tidal wetlands and dune habitat of Piping Plover, an endangered species
Geotechnical engineering
Sustainable design using recycled decking materials

Water

Waterfront and Coastal Engineering

Encore Boston Harbor Resort and Casino

Anonymous — 亚星游戏官网d, 18 Sep 2019 18:52:40 +0000

Encore Boston Harbor Resort and Casino Anonymous 亚星游戏官网d, 09/18/2019 - 14:52

Challenge

The 32-acre property on the Mystic River selected for the Encore Boston Harbor resort and casino had been impacted by historic chemical manufacturing use; much of the site was on salt marsh that had been filled with waste materials from operations at the site and/or nearby facilities. The buildings on the property were razed in the 1970s and the property had been used primarily as a material storage and staging yard since the mid-1990s, when rock and fine-grained material (鈥渢unnel muck鈥�) from the construction of the Deer Island Outfall project were stockpiled on it and later spread out. In addition, the geologic conditions varied greatly within the site. The combination of complex environmental and geologic conditions, coastal flood vulnerability, the waterfront setting, and the fast-paced nature of this mega-development project required a focused project team with a diverse set of technical skills.

Solution

During initial phases of the project, GZA participated in negotiations with the former owner regarding the extent of remediation warranted by site conditions. GZA also prepared several sections of the reports required by the Massachusetts Environmental Policy Act (MEPA), and developed cost estimates for reaching regulatory closure under the Massachusetts Contingency Plan (MCP) and for dealing with contamination encountered during construction. To meet the growing needs of the project, GZA鈥檚 involvement quickly grew to include geotechnical and marine engineering as well as comprehensive natural resources and permitting services.

Ecological Services and Resilient Design: GZA鈥檚 natural resources team conducted topographic and hydrographic surveys; performed biological surveys of the shoreline, intertidal, and sub-tidal zones; conducted extensive sediment sampling and analysis to further define the nature and extent of sediment impacts from historic operations; characterized sediments within a former ship channel to identify costs associated with dredging and reopening the channel for the project鈥檚 use; and developed plans for a Living Shoreline to return the native salt marsh and native coastal bank plant species to the fringe of the site as part of the environmental impact mitigation for the project.

Geotechnical Engineering: GZA developed geotechnical foundation design recommendations to support the 29-story tower as well as the low-rise portions of the project. With a large portion of the building footprint constructed over a multilevel garage, groundwater control was an important issue for both construction and building design. GZA evaluated foundation, groundwater control, and lateral earth support options, taking into account both the extent and depth of the basement, and both geotechnical and environmental considerations. Given the variety of building loads and subsurface conditions, multiple foundation types were utilized: slurry walls for excavation support and the support of building loads; load-bearing elements to support the tower; precast prestressed concrete piles and drilled mini piles to support low rise portions of the building; a mat foundation for the majority of the below-grade garage; and rock tiedowns to help resist hydrostatic uplift pressures.

Environmental Services: GZA designed and implemented remedial activities to address three highly contaminated areas of the site prior to building construction. In one area, in-situ stabilization was used to help neutralize low-pH groundwater. In two other areas with elevated concentrations of metals, soils were excavated and replaced. While providing Licensed Site Professional (LSP) services for the project, GZA pre-characterized and drafted disposal documentation for over 800,000 tons of soil removed from the site during building and site construction.

Waterfront Engineering: GZA was also responsible for the resilient design of the project鈥檚 waterfront marina, with over 600 linear feet of bulkhead and a 300-foot-long floating dock. Due to the soft soils at the site, a load-transfer platform was designed to support new loads and mitigate settlement concerns.

Benefit

At a total estimated design and construction value of $2.6 billion, the Encore Boston Harbor resort and casino is the largest single-phase private development in Massachusetts history. By nimbly responding to changes to the proposed project during construction, GZA was able to provide the multidisciplinary services and management skill required to help move this high-profile, technically-challenging project forward to an on-time completion date.

Insights

Comprehensive permitting/ ecological, marine, environmental and geotechnical services
Sediment sampling/analysis
Living Shoreline design
Remedial design and construction
Precharacterization program
LSP services
Geotechnical design for below-grade garage and 29-story tower
Design of floating dock, bulkhead, and load relief platform
Construction phase services
Sustainable and resilient design
2020 EBC James D.P. Farrell Award for Brownfields-Remediation Project of the Year

Massachusetts

Buildings & Real Estate Development

Water

Geotechnical Engineering Services

Environmental Site Investigation & Remediation

EHS Regulatory Compliance

Natural Resources and Ecological Services

Waterfront and Coastal Engineering

Construction Management

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