Tunnel & Underground Stabilization
Expert tunnel construction, rehabilitation, and underground stabilization services that extend asset life, ensure structural integrity, and restore aging infrastructure to like-new condition.
Understanding Tunnel & Underground Stabilization
Replacing a tunnel costs tens of millions of dollars and years of service disruption. Rehabilitation offers a smarter path—restoring full structural capacity at 10-30% of replacement cost while keeping corridors operational. Our projects routinely extend tunnel service life by 50-100 years, protecting the original infrastructure investment for future generations.
Every tunnel presents unique challenges. Railroad tunnels require work windows measured in hours between trains. Highway tunnels demand traffic management and ventilation control. Mining tunnels may have unstable ground or limited access. We've developed specialized approaches for each environment, from rope access techniques for shaft work to mobile shotcrete equipment that sets up and breaks down within tight schedule windows.
The key to lasting rehabilitation is addressing root causes, not just symptoms. That's why we pair structural repairs with pressure grouting to seal water pathways and consolidate loose ground. Rock bolting stabilizes surrounding rock mass. Tunnel support systems including steel sets and lattice girders provide immediate ground support.
Structural shotcrete is our primary rehabilitation tool—we can build up linings to 12 inches thick in multiple passes. Our ACI-certified nozzlemen produce dense, low-rebound shotcrete that bonds to prepared surfaces and develops full design strength. Both wet-mix and dry-mix processes are available depending on project requirements.
Our geotechnical investigation capabilities help identify hidden problems before they compromise new work. Concrete repair addresses localized deterioration. This integrated approach—combining structural lining, ground improvement, and water management—delivers rehabilitations that outperform original construction.
When Tunnel Stabilization Is Needed
You may require tunnel or portal stabilization when you observe: loose rock or overbreak at the crown or ribs; water infiltration or seepage staining; stress fractures, cracking, or block separation; spalling or deterioration of existing support; portal instability at the slope interface; rusted or failing rock bolts, sets, or mesh; or undermining or erosion near the tunnel entrance. Any change in rock mass behavior underground can escalate quickly—stabilization ensures continued safe operation.
Without proper intervention, these conditions typically worsen over time. Early assessment and appropriate remediation can prevent costly emergency repairs and protect the assets and people that depend on stable ground.
Common Causes
- Stress redistribution or blasting-induced fractures
- Groundwater pressure and seepage infiltration
- Weathered or weak rock zones
- Portal interaction with unstable surface slopes
- Aging, corroded, or undersized support elements
- Construction vibration and modern load demands
- Freeze-thaw damage and reinforcement corrosion
- Chemical attack from aggressive groundwater
- Original construction deficiencies
- Deferred maintenance and accumulated deterioration
Complete Underground Solutions
From initial assessment through final restoration, we provide comprehensive tunnel services that address both immediate structural concerns and long-term durability requirements. Our approach integrates structural repair with waterproofing and ground improvement for rehabilitations that outperform original construction.
Condition Assessment & Documentation
Detailed inspection and documentation of existing conditions including concrete delamination mapping, water infiltration tracking, structural deficiency identification, and ground support evaluation. Assessment establishes baseline conditions and prioritizes rehabilitation needs.
Engineering Analysis & Design
Structural evaluation determines load-carrying capacity and identifies required repairs. Design specifies lining thickness, reinforcement, waterproofing, and ground support to restore full structural capacity with appropriate safety factors. Analysis considers construction constraints of the operating environment.
Surface Preparation
Hydrodemolition or mechanical removal of deteriorated concrete to expose sound substrate for rehabilitation. Preparation removes contaminated material, undercuts reinforcing steel for proper encasement, and creates surface profile for shotcrete bond.
Ground Support Installation
Rock bolts, steel sets, lattice girders, or spiling stabilize loose ground and provide support for new lining. Ground support addresses the root cause of many tunnel failures—inadequate original support or deterioration over time.
Structural Repair & Lining
Application of shotcrete lining, installation of steel ribs, or placement of cast-in-place concrete restores structural integrity. Fiber reinforcement, welded wire fabric, or conventional rebar provides tensile capacity. Multiple layers achieve design thickness.
Waterproofing & Drainage
Installation of membrane systems, injection grouting, and drainage provisions prevents future water infiltration. Waterproofing protects the rehabilitated structure from the deterioration mechanisms that damaged the original.
How We Deliver
Our field services deliver comprehensive solutions tailored to your specific site conditions and requirements.
Why Choose Rock Supremacy
Techniques We Use
Proven engineering methods that deliver long-term stability and protection.
Draped Mesh Systems
Draped mesh systems control loose rockfall by capturing debris and guiding it downslope to a safe catchment area. Unlike pinned mesh, draped systems are not rigidly attached to the entire slope—allowing them to manage high volumes of material efficiently.
Horizontal Drains
Horizontal drains are drilled drainage systems designed to lower groundwater pressure and improve the stability of slopes, embankments, and rock faces. By relieving pore pressure, these drains significantly reduce the risk of landslides, sloughing, and long-term slope movement.
Pinned Mesh Systems
Pinned mesh systems combine steel mesh with rock bolts or dowels to create a secure, reinforced slope surface. This containment system prevents loose blocks from detaching and provides long-term stability in both civil and mining applications.
Pressure Grouting
Pressure grouting strengthens ground, fills voids, and reduces water infiltration by injecting grout into soil, fractured rock, or void spaces. This technique supports slope stabilization, foundation improvement, landslide remediation, and structural repairs.
Rock Bolting
Rock bolting stabilizes fractured, jointed, or unstable rock masses by anchoring steel bars deep into competent rock. By tying loose blocks back to stable substrate, rock bolts improve the overall strength and cohesion of slopes, cuts, tunnels, and vertical faces.
Rock Dowels
Rock dowels are passive reinforcement elements used to lock loose or fractured rock blocks into place. Unlike tensioned bolts, dowels rely on full-length grouting to create shear resistance across joints and discontinuities.
Rockfall Barriers & Fences
Engineered catch systems that intercept falling rock or debris before it reaches roadways, railways, or infrastructure. These high-energy systems absorb and dissipate impact energy safely through deformable components.
Shotcrete (Dry Mix)
Dry-mix shotcrete conveys dry material by air and hydrates at the nozzle, providing a versatile concrete application method ideal for remote sites, repair work, and intermittent applications where portable equipment and adjustable water content are advantages.
Shotcrete (Wet Mix)
Wet-mix shotcrete is pre-batched with water and pumped to the nozzle where compressed air propels it onto surfaces. This method delivers consistent mix quality, high production rates, and minimal dust—preferred for structural applications and high-volume projects.
Soldier Pile Walls
Soldier pile walls are proven earth retention systems for stabilizing deep excavations and steep slopes. Steel beams installed at intervals with lagging placed between them provide flexible, economical support that adapts to site constraints.
Structural Shotcrete
Structural shotcrete is high-strength, reinforced concrete applied pneumatically to create durable retaining walls, tunnel linings, and slope support systems. Engineered to carry significant loads, it provides monolithic construction that conforms to irregular surfaces.
Tunnel Support Systems
Tunnel support systems provide immediate ground control during excavation and long-term structural stability for underground openings. Our comprehensive capabilities include steel sets, lattice girders, rock bolts, shotcrete, and integrated support designs.
Weep Drains
Weep drains provide surface-level drainage relief by allowing water trapped behind shotcrete, retaining walls, or stabilized slopes to escape. These drains prevent hydrostatic pressure buildup, which can compromise structural stability.
Industries Impacted
We serve these sectors with specialized expertise in their unique challenges and regulatory requirements.
Our Work
See how we've delivered this solution for clients across the country.

Moffat Tunnel Portal Rehabilitation
Structural rehabilitation of the historic Moffat Tunnel portal including rock bolting, shotcrete, and drainage improvements.

Roseville Rail Yard Tunnel Repair
Emergency structural repair of a failing rail tunnel crown in one of the West Coast's busiest rail yards.
Tunnel & Underground Stabilization FAQ
Our Service Area
Rock Supremacy operates from strategic bases in Oregon and Tennessee, giving us coast-to-coast reach with direct access to the western mountains, central corridors, and the southeastern rockfall hot zones. Our teams are licensed, equipped, and trained to mobilize anywhere in the Lower 48, Alaska, Puerto Rico, Canada, and the Caribbean.
If rock is moving, sliding, cracking, sloughing, or threatening a critical asset, we can be on-site within 48 hours for emergency response. Our crews arrive with the equipment, engineering support, and shotcrete/ground-stabilization systems required to stop the problem—not just manage it.
Where We Work
- United States: Lower 48 + Alaska
- Territories: Puerto Rico
- International: Canada + Caribbean
- Remote and rugged access
Our Strategy
- Two operational bases
- Rapid emergency dispatch
- Certified technicians
- Full-scale capability on arrival
Western Division (HQ)
Eastern Division
About Rock Supremacy
Rock Supremacy is North America's premier geotechnical contractor specializing in rockfall mitigation and slope stabilization. Our team combines technical expertise with uncompromising safety standards.
From the steep canyons of Colorado to the coastal bluffs of California, we've developed proven methodologies for stabilizing slopes and protecting critical infrastructure. Our crews are trained to work in the most demanding vertical environments.

Our Safety Record
We maintain a safety-first culture because we believe every worker deserves to go home safe at the end of the day. This commitment to safety has earned us the trust of DOTs, mining companies, and energy providers across the country.
All crew members receive ongoing training in high-angle rescue, fall protection, and hazard recognition. We conduct daily safety briefings and maintain rigorous equipment inspection protocols.
Client Testimonials
Trusted by DOTs, engineering firms, and property owners nationwide.
Deploy Us
Ready to discuss your project? Our team is standing by to assess your site conditions and develop a custom tunnel & underground stabilization solution.
Emergency (24/7)
(541) 383-7625Bidding & Estimates
Info@RockSupremacy.comHeadquarters
Licensed in CO, UT, WY, ID, MT, CA, WA, OR, TN, VA
Request Consultation
Ready to Get Started?
Our team is standing by 24/7 for emergency response or to schedule a site assessment for your next project.











