When structural integrity is compromised on a municipal scale, temporary fixes and inexperienced contractors simply will not cut it.
Recently, a subcontractor for the City of Denver faced a massive crisis. They were tasked with stabilizing a vital municipal pedestrian tunnel that had begun to structurally fail and collapse. Due to a complete lack of familiarity with specialized concrete restoration, the subcontractor's progress ground to a halt. Recognizing the public safety hazard, the City of Denver completely shut down the project for over two months —until they found the structural repair experts at Alpine Companies.
Here is how Harold M Lesser II (Jay) , owner-operator of Alpine Companies, stepped in to engineer a permanent solution using advanced structural epoxy injection.
The Diagnostics: Hydrostatic & Frost Pressure Failure
The pedestrian tunnel's structural integrity was heavily compromised by severe local environmental factors and improper drainage:
- Summer Hydrostatic Pressure: Poor drainage caused massive amounts of groundwater to pool along the exterior concrete walls of the tunnel, exerting immense lateral hydrostatic pressure.
- Winter Frost Shoving: In the colder months, this trapped pooling water froze and expanded, creating aggressive inward forces against the concrete.
The combination of shifting seasonal pressures caused deep, structural fracturing across the concrete framework, threatening a catastrophic localized collapse.
The Alpine Action Plan (POA)
While the project sat dormant for over 60 days, Jay Lesser immediately formulated a comprehensive Plan of Action (POA). Leveraging Alpine's unique engineering insight, the POA detailed an aggressive structural restoration strategy designed to handle both the active fractures and the environmental pressures.
The City of Denver reviewed, approved, and greenlit Alpine’s plan without delay.
The Execution: 300+ Ports, Custom Viscosity Formulation
Restoring a heavily fractured underground tunnel requires precision pressure management and material engineering. The Alpine crew deployed a multi-stage low-pressure injection strategy:
- Precision Port Placement: Our team mapped and installed over 300 specialized injection ports systematically along the entire fracture network to ensure full-depth penetration.
- High-Volume Low Viscosity (LV) Injection: We injected 11 gallons of Low Viscosity (LV) structural epoxy to weld the primary structural cracks, penetrating deep into the concrete core to re-establish a monolithic bond.
- Super Low Viscosity (SLV) Penetration: To tackle micro-fissures and hairline fractures where water had begun to spiderweb, we utilized 4 gallons of Super Low Viscosity (SLV) epoxy , ensuring no void was left unsealed.
The Outcome: Restored in Just 9 Days
While the previous crew left the project at a standstill for two months, Alpine Companies executed the entire engineering scope, sealed all 300+ ports, and fully restored the structural integrity of the concrete tunnel in just 9 days.
The cured epoxy now boasts a tensile strength that far exceeds the original concrete matrix, permanently protecting the tunnel from future frost cycles and hydrostatic shifts.
Need Commercial or Residential Structural Epoxy Injection in Colorado?
Whether it is a municipal pedestrian tunnel under the City of Denver or a residential basement foundation wall shifting against Colorado's expansive bentonite clay, Alpine Companies delivers engineer-approved results. We don't patch symptoms—we fix the engineering problem.
Schedule Your Structural Evaluation with Jay Lesser Today
Call Our Main Office: (303) 797-8908