How The Dwyer Company Engineered Deep Foundation Support for Mackinnon Hall Elevator Installation
- Project Type: Commercial
- Project Services: Deep Foundation Systems, Helical Piles, Push Piers
When Mackinnon Hall at the University of Toledo required renovations to support a new elevator pit, the project demanded a deep foundation system for the existing structure. The project presented unique engineering challenges: soft soils in the upper 30 to 40 feet required deep load transfer to competent bearing layers, while extremely limited site access demanded precision execution in confined spaces. The access into the site was so tight, with severely restricted headroom, that the crew had to remove the excavator cab just to fit equipment inside the building to install the piers. In close collaboration with Van Tassel Construction Corporation and Civil Solutions, The Dwyer Company designed and installed 11 helical piers extending approximately 28 feet to bypass weak surface soils, with each pier supporting between 15 and 19 kips; proving that even the most constrained renovation projects can achieve structural integrity with the right attention to detail and adaptive approach.
Quick Facts
- Location: Toledo, Ohio
- Project Type: Retrofit / Helical Pier Foundation System
- Key Metric: 11 helical piers installed with load capacities between 15 and 19 kips
- Key Metric: Helical piers extended approximately 28 feet to reach competent bearing strata
- Key Metric: Installation completed with excavator cab removed due to extreme headroom constraints
- Key Metric: Zero structural settlement despite soft upper soils and challenging access conditions
- Timeline: Completed within aggressive construction schedule with no delays to subsequent phases
- Partners: Van Tassel Construction Corportation; Civil Solutions
The Challenge:
The primary challenge was installing a foundation system capable of supporting a new elevator pit through 30 to 40 feet of soft, unsuitable soils in an environment with the most extreme access constraints our team had encountered, requiring precision navigation in a site so tight and with headroom so limited that we had to disassemble the excavator cab just to fit drilling equipment inside the building. The installation demanded extraordinary attention to detail to avoid damaging existing building infrastructure, utilities, and architectural features while executing precise helical pier placement in a workspace that left virtually no margin for error. Conventional foundation methods couldn’t achieve the required deep load transfer in such confined conditions without extensive building modifications or complete demolition and reconstruction.
The Solution: Precision Helical Pier System in Extreme Constraints
The Dwyer Company, in partnership with Civil Solutions engineering, designed and installed an 11-helical pier foundation system that transferred elevator pit loads through 30 to 40 feet of soft upper soils to competent bearing strata below. The solution required detailed pre-installation planning to map every overhead obstacle and existing building element, specialized compact equipment modified to operate with the excavator cab removed, and meticulous execution to install piers in a workspace with virtually zero tolerance for equipment contact or installation error.
The installation process involved carefully maneuvering modified drilling equipment through the building interior with removed excavator cab, establishing precise pier locations within the elevator pit footprint, and executing helical pier installation to approximately 28-foot depths while navigating utilities, structural elements, and architectural features in extremely close quarters. Each of the 11 piers was engineered to support between 15 and 19 kips based on specific load requirements, with helical plates configured to engage competent bearing layers and bypass the soft upper soil profile entirely.
The entire installation maintained the project’s aggressive renovation timeline, providing University of Toledo with a permanently stable foundation system that supports the new elevator pit and eliminates settlement risk despite challenging soil conditions and the most constrained installation environment imaginable.
Key Project Details
Helical Pier Scope
helical piers installed within elevator pit footprint to support new vertical transportation system
Load Capacity
15–19kips
individual pier capacities based on engineered load distribution requirements
Pier Depths
to bypass 30-40 feet of soft upper soils and engage competent bearing strata
Extreme Access Solution
Excavator cab removed to achieve building entry; installation completed in severely restricted workspace with minimal headroom
Precision Execution
Extraordinary attention to detail required to avoid contact with existing building elements, utilities, and architectural features during installation
Project Coordination
Seamless collaboration with Van Tassel Construction Corporation and Civil Solutions to navigate constraints and maintain renovation schedule
Why helical piers for Mackinnon Hall at University of Toledo?
The Dwyer Company’s helical pier foundation system delivered the deep load transfer and installation precision required for this extreme-access university renovation project.
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Extreme Access Capability
Helical pier installation using compact, modified equipment successfully navigated the building interior with removed excavator cab and severely restricted headroom where conventional deep foundation methods would have required building demolition or prohibitively expensive structural modifications. -
Deep Load Transfer Through Soft Soils
The 28-foot helical piers bypassed 30 to 40 feet of soft, unsuitable upper soils and transferred elevator pit loads directly to competent bearing strata, ensuring zero settlement risk for the vertical transportation system. -
Precision Installation Control
Helical pier technology allowed precise torque monitoring and installation control in the confined workspace, ensuring each pier achieved required capacity without the extensive testing and verification that would have been impossible in such tight quarters. -
Minimal Building Impact
The compact installation process avoided damage to existing building elements, utilities, and finishes despite working in extraordinarily tight conditions—eliminating the costly repairs and rework that conventional foundation methods would have caused. -
Variable Load Distribution
Engineering piers for 15 to 19 kip capacities allowed optimized foundation design that matched actual elevator pit load patterns without over-engineering every location or creating unnecessarily large foundation footprints.
The Impact: Precision Execution in Impossible Conditions
Adaptive Problem-Solving
Removing the excavator cab to achieve building access demonstrated the creative problem-solving and determination to deliver results even when site conditions appeared impossible—finding solutions instead of making excuses.
Schedule Preservation
Completing the helical pier installation despite extreme access constraints prevented delays that would have cascaded through subsequent elevator installation phases and avoided disruption to university operations and the academic calendar.
Zero Structural Settlement
Most critically, the precision installation achieved zero structural settlement while navigating the most constrained workspace imaginable—providing University of Toledo with a permanently stable elevator pit foundation that bypassed 30 to 40 feet of soft soils and will support decades of reliable vertical transportation service in Mackinnon Hall.
Why Choose The Dwyer Company for Structural Integrity?
Deep History • Solid Choice
The Dwyer Company’s proven track record in commercial and industrial foundation systems made us the trusted partner for this critical infrastructure project. Our team’s technical expertise, advanced equipment, and commitment to precision execution delivered a foundation system that will support decades of heavy industrial use.