Eldon L. Abbott, PE

Principal Engineer
Tunnels & Geotechnical

Eldon has over 40 years of professional experience covering a broad range of geotechnical engineering, tunneling, transit, marine facilities, and large subterranean structures. Prior to joining Reliance, Eldon was Vice President, Principal Project Manager, and Senior Professional Associate with Parsons Brinckerhoff. Over his career, he served as the Project Manager and/or Technical Director of such noteworthy projects as the tunnel crossing under the Main Shipping Channel in Miami’s Biscayne Bay on behalf of the Florida Department of Transportation (FDOT); design and construction phase services for the North Dorchester combined sewer overflow (CSO) tunnel in South Boston; Construction-phase services for the Boston Harbor Effluent Outfall Tunnel, which, upon completion, was the longest single-entry tunneled outfall in the world; underground portions of a $96 million healthcare facility with a five-level underground parking garage; design of the award-winning 1,400-car, seven-level underground Post-Office Square Parking Garage and Urban Park in Boston. Eldon also authored the section on “Preparation of Contract Documents for Subsurface Projects” in the text Subsurface Conditions, Risk Management for Design and Construction Management Professionals published by John Wiley & Sons, Inc. in 1998.

Educational Background

  • M.S. Civil Engineering, Clarkson College (now University), Potsdam, NY, 1968
  • B.S. Civil Engineering, Clarkson College (now University), Potsdam, NY, 1966

Registered Professional Engineer

Professional Engineer – New York, Massachusetts, Michigan.

Selected Projects

Toronto Subway System Expansion: Eldon is currently serving as a Tunnel Consultant to HDR, Inc in Toronto, Ontario Canada on two sections of the greater Toronto subway system. Both sections are in concept design stage and Eldon’s current participation includes evaluating alternative alignments. Both projects are in heavily urban settings with rock and mixed face tunnels and potentially several mined stations.

MTA, Value Engineering for the Second Avenue Subway, New York, Phase 2 Project: Eldon participated as the lead Tunnel Engineer in the Value Engineering Study for the Second Avenue Subway Phase 2 project. Phase 2 will be a twin-tunnel, approximately 1.8 miles long, connecting the Second Avenue subway Phase I bulkhead at 105th Street and 2nd Avenue on the south and ending at storage tracks at 125th Street and Lennox Avenue. There are three subway stations proposed connected by the twin tunnels (2018-Current)

SR99 Deep Bored Tunnel, Seattle, Washington: Task Lead for the Design-Build Criteria documents on behalf of WashDOT for this $1.9 Billion, 50-foot internal diameter highway tunnel where the roadways are stacked one over the other, with two lanes in each direction. The tunnel is approximately 2 miles long and will replace the aging Alaskan Way Viaduct that was damaged in a recent earthquake. The Design-Build contract was awarded in 2010 and the tunnel construction is currently underway.

Sound Transit, Seattle, Washington: Tunnel Engineer working for the Puget Sound Transit Consultants, JV, responsible for tunnel engineering, construction methods, determination of impacts and mitigation measures, risk assessment and preparation of construction methods for the draft environmental impact report for the North Link Transit Alternatives Analysis for the system running from downtown Seattle north to the University of Washington. Seven alternative tunnel alignments were evaluated for the study.

Port of Miami Vehicular Tunnel Design/Build/Finance (P3), Florida: Project Manager for the preparation of Design Build criteria documents for the Concession on behalf of FDOT for twin 42-foot diameter vehicular tunnels linking the Port of Miami with interstate highways I-395 and I-95 in downtown Miami. The project will provide improved port access for vehicular traffic and consists of two 3,000-ft long, two-lane tunnel crossings under the main shipping channel between the MacArthur Causeway on Watson Island and the Port of Miami on Dodge Island, all located in Biscayne Bay. Technical challenges included the control of groundwater during excavation for cut-and-cover approach tunnels, finding and filling of voids or very loose sand layers in the limestone bedrock lying in or just below the tunnel horizon that could endanger the tunnel boring equipment during construction and grouting of voids in this vuggy bedrock to seal water inflows. Project was completed in 2015 and is now open to traffic.

North Dorchester CSO Tunnel, Boston, Massachusetts: Project Manager for the design of a 17-ft diameter soft ground tunnel for the MWRA for storage and pumping capacity to enable the permanent closure of seven combined sewer outflows into North Dorchester Bay within Boston Harbor. The CSO tunnel was driven in soft ground consisting of mostly glacial outwash sands and gravel and glacial marine clays, primarily Boston Blue Clay. This 11,100-ft long $150 million tunnel has a crown depth of 25 to 55 feet below ground surface and was constructed using an earth pressure balance tunnel boring machine (TBM) and precast concrete segmental gasketed, bolted linings. The proximity of the Atlantic Ocean and the presence of hydrocarbon pollutants from neighboring petroleum storage facilities required limiting drawdown and water infiltration. Connections between the existing CSO outfalls and the new tunnel consists of helicoidial-ramp type dropshafts to minimize need for deaeration chambers and the length of connecting pipes between the tunnels and dropshafts.

Harvard Square Station, Cambridge, MA: Supervising Engineer for the construction-monitoring program. Involved field measurements of ground movements and construction loads during station construction to give advance warning of conditions that might damage nearby buildings. Also served as a geotechnical engineer for the design of the station, including evaluation of subsurface environs for slurry wall excavation, preparation of a geotechnical design summary report, and specifications and programs for building protection during construction. This project marked the first use of slurry walls as part of a permanent transit structure.

Post Office Square Park & Garage, Boston, MA: Project Manager for the design of a 1,400-car, seven-level, underground parking garage in the heart of Boston’s financial district. Services included civil, traffic, permitting, construction services and geotechnical engineering as well as coordination of the landscaping and architecture for a 1.7-acre street-level park. Construction of the garage employed the top-down method and required extensive monitoring of perimeter slurry wall for lateral movement. The roof of the garage is a richly landscaped urban park. The project, completed in 1990, has won several awards including the Grand Conceptor Award from the American Consulting Engineers Council of New England.

Clinical Center Ambulatory Care Facility, Beth Israel Hospital, Boston, MA: Project Manager for the underground portions of a $96 million health care facility on Longwood Avenue. The 12-story clinical center, completed in 1993, included a five-level, 750-car below-grade parking garage. Construction issues involved slurry wall design and retention of the facade of the historic Massachusetts College of Art Building. Project included preparation of construction management and phasing plans, document control on-site representation as well as design review of geotechnical and structural elements.

Second Downtown Elizabeth River Tunnel, Norfolk and Portsmouth, Virginia: Geotechnical program manager for the field exploration and laboratory testing program to determine the geotechnical design parameters for a second immersed-tube tunnel beneath the Elizabeth River. The heavily over-consolidated clays near the Norfolk shipyards were analyzed by the Stress History and Normalized Soil Engineering Properties (SHANSEP) approach. Also provided preliminary, final design and environmental services for this two-lane, 3,810-ft long tunnel.