Gall Zeidler Consultants

What Gall Zeidler Consultants does

Gall Zeidler Consultants (GZ) is a Virginia-based professional engineering consultancy founded in 2000 by Vojtech Gall and Kurt Zeidler. The firm provides specialist tunnel and underground engineering services across the full project lifecycle: feasibility and concept studies, reference and detailed design, geotechnical and structural numerical modeling, BIM and digital twinning, procurement support (including PPP advisory), construction supervision, program and construction management, instrumentation and monitoring, and tunnel rehabilitation and waterproofing. It executes projects across NATM/SEM, TBM and cut-and-cover construction methods and addresses difficult ground conditions including squeezing, swelling, and rock-burst prone environments. Five market verticals are served: Rail and Transit, Transportation, Power (including hydropower and pumped storage), Water and Wastewater, and Mining.

GZ operates through ten offices across five continents (Ashburn, New York, Walnut Creek, Toronto, Santiago, London, Salzburg, Singapore, Gurgaon, Adelaide), with named client engagements including HS2 (Contracts C1, N1, N2 in the UK), Crossrail/Elizabeth Line, the Hudson Tunnel Project (Gateway Program Delivery Partner), BART Silicon Valley Phase II Extension, MTA Grand Central Madison, WMATA, VDOT Hampton Roads, DC Water Potomac River Tunnel, and Thames Water (UK). These are predominantly government transit authorities, rail authorities and water utilities; commercial/private infrastructure owners are also served. Revenue is generated entirely through professional services contracts; pricing is not publicly disclosed. The firm has executed over 300 miles of tunnel projects worldwide and celebrated its 25th anniversary in 2025, with second-generation leadership (Vojtech Ernst Gall) elevated to Principal and Vice President alongside founders and additional partners.

The senior technical bench is heavily credentialed (multiple PhDs, Chartered Engineers, PEs) with active participation in ASCE, UCA, ITA, ISRM, BTS, Czech Tunneling Association and Tunnelling Association of India. Core proprietary capabilities are centered on 2D/3D numerical modeling of underground construction behavior and BIM-driven digital project delivery, differentiating GZ from generalist engineering consultancies on complex, technically demanding tunnel and underground programs.

Name

Gall Zeidler Consultants

Legal name

Gall Zeidler Consultants, L.L.C.

Website

https://gzconsultants.com

Company type

Private

Founded year

2000

Operating status

Operating

Headcount range

11–50 employees

Short description

Gall Zeidler Consultants is a Virginia-founded tunnel and underground engineering consultancy (est. 2000) serving government transit authorities, rail authorities and water utilities across the Americas, Europe, Asia and Australia with feasibility, design, program management, construction supervision and rehabilitation services.

Ownership category

akta.pro rank

Headquarters

HQ city

Ashburn

HQ country

United States

HQ region

North America

Offices10 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Marketing or Sales, Technology or R&D, Infrastructure

Revenue model

1. Engineering Consulting Services: The company generates revenue through professional engineering consulting services for tunnel and underground projects, including design, program management, construction management, and technical advisory services.
2. Design Services: Reference and detailed design services for tunnels and underground structures across transportation, water, power, and mining markets.
3. Program Management Services: Program management services for major infrastructure projects ensuring delivery on schedule, within budget and to quality standards.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels4 records

Core offering

Gall Zeidler Consultants provides professional engineering consulting services for tunnel and underground infrastructure projects. Its core offerings include reference and detailed design, program management, construction management, construction supervision, geotechnical investigation, BIM and digital twinning, and tunnel rehabilitation. The firm applies conventional tunneling (SEM/NATM/SCL), mechanical tunneling (TBM), and cut-and-cover methods combined with ground improvement and waterproofing techniques to deliver full-lifecycle services from feasibility through design, construction, and rehabilitation across rail/transit, transportation, power, water/wastewater, and mining markets.

Product overview

Gall Zeidler Consultants (GZ) is a specialized tunnel and underground engineering consulting firm offering a comprehensive suite of professional services organized around core engineering deliverables and market verticals. The core service portfolio spans the full project lifecycle — from Design Concepts, Options and Feasibility studies through Reference and Detailed Design, Geotechnical Investigation Programs, Geotechnical and Structural Modeling, Procurement, Construction Supervision and Support, and Construction Management, capped by Program Management for major infrastructure programs. Supporting specialized services include BIM and Digital Twinning, Alternatives and Value Engineering, Deep Excavation and Slope Support, Tunnel Rehabilitation, Mine Support, and Instrumentation and Monitoring. These services are applied across five market segments: Rail & Transit, Transportation, Power, Water & Wastewater, and Mining. The firm operates globally through offices in North America, South America, Europe, Asia, and Australia, and employs conventional tunneling methods (SEM/NATM/SCL), mechanical tunneling (TBM), and cut-and-cover methods combined with ground improvement and waterproofing techniques. Founded in 2000, GZ has executed over 300 miles of tunnel projects worldwide.

Differentiator

Problem solved

Functional benefit

Products and services

• Reference and Detailed Design Design services developing state-of-the-art project-specific design solutions for tunnels and underground structures using conventional tunneling (NATM/SEM), mechanical tunneling (TBM), and cut-and-cover construction methods. Targeted at owners and contractors on major transportation, water, power, and mining projects.
• Program Management Program management services for major infrastructure projects ensuring delivery on schedule, within budget, and to the highest quality using state-of-the-art tunneling technologies. Targeted at public agencies and large infrastructure owners running multi-project programs.
• Construction Management Construction management services covering the entire course of tunnel construction from tunnel boring, lining, and waterproofing through to installation of tunnel systems. Targeted at owners and contractors executing tunnel construction projects.
• Design Concepts, Options and Feasibility Development of feasibility studies, project options, and design concepts for projects in dense urban areas or remote alpine environments. Targeted at project owners and authorities evaluating alternative underground configurations before committing to design.
• BIM and Digital Twinning Building Information Modeling and digital data management services to increase collaboration, improve project delivery, and simplify asset management across a project's lifetime, including 3D/4D/5D planning and as-designed versus as-built model comparisons. Targeted at tunnel and underground infrastructure owners and contractors.
• Alternatives and Value Engineering Value engineering and alternative design services ensuring project requirements are met with economical and time-saving solutions without sacrificing quality. Targeted at project owners seeking cost and schedule optimization on tunnel and underground projects.
• Geotechnical Investigation Programs Ground investigation programs including on-site supervision of drilling, sampling, and testing, and interpretation of collected geotechnical and geological data. Targeted at owners and design teams needing ground risk data for tunneling and underground projects.
• Geotechnical and Structural Modeling Development of detailed 2D and 3D numerical models to simulate construction of sub-surface projects, capturing dominant physical phenomena controlling underground construction behavior. Targeted at design teams and owners facing complex ground conditions.
• Procurement Project procurement services from Design-Bid-Build to Public-Private Partnerships, including RFQ/RFP preparation, contract administration, and bid evaluation support. Targeted at public owners executing major underground infrastructure procurements.
• Construction Supervision and Support On-site construction supervision and senior engineering support ensuring design implementation to the highest quality with strict quality control procedures. Targeted at owners and contractors executing tunnel and underground construction.
• Deep Excavation and Slope Support Design of stable and long-lasting slope and excavation support systems using geotechnical expertise, including remediation measures for existing slope instabilities. Targeted at owners and contractors needing shaft and slope support for underground projects.
• Tunnel Rehabilitation Extensive tunnel rehabilitation services ensuring rehabilitated tunnels fulfill their intended purpose for their new design life, using state-of-the-art waterproofing and strengthening techniques including membrane-based and curtain grouting systems. Targeted at transit authorities and owners extending the life of aging underground assets.
• Mine Support Mining engineering and geological solutions for mine project challenges at all stages of development from conception through construction to production. Targeted at mining companies needing underground access design, geotechnical investigations, and slope stability.
• Instrumentation and Monitoring Instrumentation and monitoring solutions ensuring structures are monitored adequately and precisely to ensure safety and stability before, during, and after construction. Targeted at owners and contractors executing tunnel and underground projects.

Quantifiable outcome

• Successfully executed over 300 miles of tunnel projects globally

Named customers10 records

Segments5 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Scale indicators3 records

Recent moves15 records

Expansion highlights6 records

Direct peers

• Arup: Global engineering consultancy with a prominent tunneling and underground infrastructure practice serving transit, water, and energy clients. Comparable in serving government infrastructure owners on complex underground schemes and competing for the same mega-program commissions.
• Mott MacDonald: International engineering consultancy with deep tunneling, rail, and water expertise. Directly comparable in delivering detailed design, program management, and construction management for major underground infrastructure programs globally.
• COWI: Engineering consultancy with a strong tunneling and underground structures practice, including involvement in major immersed tube and TBM tunnel projects. Comparable in technical methods (SEM/NATM, TBM) and government/transit client base.
• Hatch: Engineering consultancy with deep mining and underground infrastructure expertise, including tunnel and hydropower design. Comparable in serving mining and hydropower clients on underground works and geotechnical challenges.
• Dr. Sauer & Partners: Specialist tunneling consultancy focused on SEM/NATM design and construction support. Highly comparable niche specialist competing for similar SEM/NATM-based tunnel design commissions worldwide.

Broad incumbents

• WSP: Global professional services firm with a major tunnel and underground infrastructure group. Overlaps with GZ on transit, water, and transportation tunnel design and program management, but operates at significantly larger scale.
• AECOM: Large global infrastructure consulting firm with tunneling capability embedded in its transportation and water practices. Competes for the same megaprogram commissions but offers a much broader portfolio of services.
• Jacobs: Major engineering and program management firm serving transit, water, and infrastructure clients. Participates in tunneling design and construction management on large public infrastructure programs similar to GZ's portfolio.
• Stantec: Engineering, architecture, and environmental services firm with tunnel and water conveyance expertise. Overlaps with GZ on water/wastewater tunnel design and transit infrastructure programs across North America.
• Bechtel: Global engineering, procurement, and construction firm with major underground and tunneling capability on rail, water, and hydropower programs. Competes for program management and construction management roles on the same megaprojects as GZ.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat6 records

Key risks5 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/gall-zeidler-consultants-llc
• Xx.com/GZConsultants

Revenue estimate

Valuation estimate

Number of profiles

Profiles13 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Gall Zeidler Consultants