Tunneling And Underground Structures

Groundbreaking Tunnel Innovation

We offer innovative solutions to some of the largest, most complex tunnel and underground construction projects in the world. Our experts are dedicated to overcoming the toughest challenges to help customers move safely under or through any obstacle.

Explore Our Integrated Capabilities

Our underground construction experience ranges from small excavations to large underground transit systems, water and wastewater infrastructure, and hydroelectric projects. We utilize the latest approaches, including 3D modeling, building information modeling (BIM), and conventional and machine-bored tunneling to deliver state-of-the-art projects and processes. We provide a single source of integrated capabilities for the following:

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  • Planning
  • General consulting
  • Project management/construction management (PM/CM)
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  • Geological investigations
  • Geotechnical engineering/geotechnical monitoring and instrumentation
  • Risk management and resiliency analysis
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  • Tunnel excavation and support design
  • Seismic analyses
  • Tunnel system design
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  • Tunnel inspection, rehabilitation, and retrofit
  • Value engineering
  • Constructability reviews
  • Construction engineering services
  • Commissioning

Our Underground Construction Capabilities And Experience

We have been provided advisory services, performed subway construction, and delivered major underground infrastructure/tunneling projects, including the Southern Nevada Water Authority Lake Mead Intakes 2 and 3, the New York Department of Environmental Protection’s Delaware Aqueduct Rondout-West Branch Bypass Tunnel, Delta Conveyance Tunnel, Frederick Douglas Tunnel, DTX (Downtown Rail Extension) and the Hudson Tunnel Project.

As an integrated solutions provider, we are experts in alternative project delivery methods. This includes design-build (DB), public-private partnerships (P3s), and design-build-finance-operate-maintain (DBFOM).

In a joint venture (JV), we have been acting as the owner’s engineer for the Louis-Hippolyte La Fontaine Tunnel since March 2018.

Underground Construction Methodologies

We provide various types of underground construction including but not limited to:

  • Mined tunnels
  • Bored tunnels using Tunnel Boring Machines (TBM)
  • Cut-and-cover tunnels
  • Trenchless technology (microtunneling, horizontal directional drilling, etc.)
We are providing detailed design services for a new sewer main and pumping station upgrade to provide additional capacity for future development in West Vaughan, located within the greater Toronto, Canada area.

Delivery Methods

We provide various delivery methods including but not limited to:

  • Design-bid-build
  • Design-build
  • Public-private partnership
  • Progressive Design Build
  • CMAR

Over 70 Years Of Expertise

For over 70 years, we’ve planned, designed, engineered, built, and managed complex tunnels from transit to sewers and pipelines, in challenging geologic environments. Our unparalleled experience includes over 250 tunnels around the globe.

We serve the underground engineering and project/program management requirements  of a wide-ranging domestic and international client base. We deploy our expertise across various projects, including wastewater tunnels, combined sewer overflow (CSO) systems, road and transit tunnels, as well as other underground structures like utilities, water storage facilities, and underground buildings. We are committed to providing innovative and cutting-edge tunneling techniques and technologies to mitigate risks associated with underground constructions of all sizes and levels of complexities.

We offer a host of cutting-edge tunneling techniques to minimize risks associated with underground structures of all complexities.

MPA Delivery Partners Selected for Hudson Tunnel Project, The Most Urgent Infrastructure Project in the U.S.

CHANTILLY, Va. (February 28, 2024) – Parsons Corporation (NYSE: PSN), as part of the Mace-Parsons-Arcadis (MPA Delivery Partners) joint venture, announced today that the team has been selected by the […]

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Louis-Hippolyte La Fontaine Tunnel — Quebec, Canada

The ministère des Transports et de la Mobilité durable (MTMD) of Quebec is currently undertaking a major rehabilitation project for the Louis-Hippolyte-La Fontaine Tunnel. The goal of the rehabilitation is […]

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Deer Creek Tunnel

Deer Creek Sanitary Tunnel And Pump Station —St. Louis, MO

We have been working with the Metropolitan St. Louis Sewer District (MSD) since 2011 on the Deer Creek Sanitary System Program, and in 2016 design work was completed for the […]

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Southern Nevada Water Authority

Southern Nevada Water Authority Program And Construction Management — Las Vegas, Nevada

Since 1993, Parsons has provided program and construction management services to the Southern Nevada Water Authority (SNWA)—the agency responsible for addressing Southern Nevada’s water needs—on its major capital program. Our […]

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Rua Al-Madinah — Al-Madinah Al-Munawarah, Saudi Arabia

We are providing construction project management consultancy and contract administration services for the mega real estate project, Rua Al-Madinah, in Saudi Arabia. This project includes a 5km tunnel. Rua Al-Madinah […]

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Anacostia River Tunnel

Anacostia River Tunnel Project – District Of Columbia (D.C.)

Our tunnel experts assisted the District of Columbia Water and Sewer Authority (DC Water) with implementing a long-term control plan (LTCP) for the Anacostia River Tunnel and its combined sewer […]

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Westside Purple Line Extension Section One — Los Angeles, CA

Los Angeles Metro’s Westside Purple Line Extension Section 1 project is the first of three sections along the new 9.1-mile subway corridor. Section 1 extends the subway 3.92 miles, starting […]

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Joint Water Pollution Control Plant Sewer Tunnel Outfall — Los Angeles, CA

We are the lead designer for the Joint Water Pollution Control Plant (JWPCP) Sewer Tunnel Outfall Tunnel project. The Sanitation Districts of Los Angeles County are 24 independent special districts […]

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Delaware Aqueduct Rondout-West Branch Bypass Tunnel

Delaware Aqueduct Rondout-West Branch Bypass Tunnel – Newburgh, NY

We provide comprehensive Construction Management (CM) services for New York City’s Delaware Aqueduct Bypass Tunnel project located in the Mid-Hudson Valley of Lower New York. We have been the CM […]

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Related Capabilities


Improve the management, efficiency, and safety of transportation networks – whether freeway, highway, toll road, transit route, or tunnel.

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Water And Wastewater Solutions

Water is the life source of every community, and our mission is to help preserve it by creating and maintaining safe, efficient, and sustainable water facilities and processes. 

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Global Infrastructure

For 80 years, our experts have delivered global infrastructure that has connected and protected communities around the world.

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Water Solutions

Our PM/CM, engineering, design-build, hydrogeology, modeling, and 3D/4D visualization expertise, combined with our innovative solutions such as our state-of-the-art treatability and R&D laboratory, have helped us deliver holistic and cost-effective solutions to some of the most complex water projects in the world.

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Urban Development

For +75 years, we have specialized in the management of large, complex, multisite, and mega mixed-use and urban development programs throughout the world.

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Remediation And Treatment Solutions For A Cleaner Planet

We stand ready to meet environmental stewardship challenges for air, land, and water. Our experts use the latest technologies to deliver a cleaner, safer planet for our customers and future generations.

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Interested In Learning More?

We deliver innovative infrastructure that incorporates sustainability and resiliency to serve the needs of communities for years to come. No matter the challenge, we do what it takes to get the job done.

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