The Bethel Regional High School in Bethel, Alaska, needed to expand its campus with a 5,000-square-foot cafeteria and event space—a critical addition for the school community, which had been operating without a cafeteria since its original construction.
The site presented significant foundation challenges, including silty sand soils and permafrost located 26 feet below grade. To ensure long-term stability and protect the permafrost layer, the project required a foundation system that could handle the load while minimizing disturbance to the surrounding soil. PierTech’s helical pile system was selected as the ideal solution.
The foundation utilized a total of 62 helical piles, including:
Each pile was designed for an allowable compression capacity of 120 kips, ensuring the structure could be fully supported on the challenging soils.
Piles were advanced to an average depth of 35 feet and torqued out at approximately 50,000 ft-lbs. Installation was completed using PierTech’s 70K and 100K drive heads, allowing for the torque and control required in these conditions.
The 62-pile installation was completed in roughly six weeks, after which thermosyphons and monitoring tubes were drilled and placed to maintain frozen ground and prevent long-term settlement.
PierTech’s helical solution provided:
Helical Pile Foundation for Auditorium Expansion in Tight Site Conditions
Mount Olivet Lutheran Church in Minneapolis, Minnesota, planned a major expansion with a new auditorium addition adjacent to the existing structure. The site presented two major challenges: poor soil conditions and limited working space near the current building.
To minimize disturbance and deliver a stable foundation solution, the project team selected PierTech’s patented helical pile system—engineered for deep foundation stability and efficient installation in challenging conditions.
The foundation design utilized 90 helical piles featuring PierTech’s 2-7/8" x .362" wall Cross Lock™ patented connection system, with each pile supporting an allowable compression capacity of 45 kips.
The pile configuration included:
To optimize efficiency and reduce material handling, the leads and extensions were manufactured in 15-foot sections, streamlining installation at significant depths.
The piles were installed to depths ranging from 65 to 90 feet, with 15-foot section leads and extensions assembled on-site for faster advancement. Installation was completed using a PierTech 12K drive head, ensuring the torque and control necessary to handle the soil profile and depth requirements.
Despite the tight working area, PierTech’s helical system allowed crews to complete the work efficiently and safely without disrupting the existing church structure.
PierTech’s helical solution delivered:
High-Capacity Helical Foundation Solution for Critical Infrastructure Expansion
The Williston Water Treatment Plant in Williston, North Dakota, underwent a major expansion to double its capacity and better serve the growing community. The site’s poor soil conditions required a vibration-free foundation system that could deliver high load capacity without disturbing surrounding infrastructure.
To meet these strict requirements and keep the project on schedule, the contractor selected PierTech’s Hercules™ Pile system—a proven deep foundation solution designed for strength, speed, and low-impact installation.
The foundation plan called for:
The piles were designed to transfer loads into a stable claystone and shale strata, ensuring long-term structural reliability despite the site’s upper soil challenges.
The Hercules™ piles were advanced to an average depth of 45 feet, terminating on the claystone/shale bearing layer. The installation was completed using a PierTech 40K two-speed drive head, which provided the torque and control needed to achieve the required depths and capacities efficiently.
The vibration-free process minimized disruption to nearby plant operations and surrounding structures, ensuring a smooth and compliant installation.
PierTech’s helical foundation solution delivered:
High-Capacity Helical Solution for a Five-Story Parking Structure
The Roberts Ramp Garage in Fargo, North Dakota, required deep foundation support for a five-story elevated parking structure. Challenging subsurface conditions, strict jobsite requirements for low noise and vibration, and the need for a high-capacity, cost-effective solution made PierTech’s Hercules™ Pile system the ideal choice.
To meet the structural demands of the project, PierTech supplied 10 ¾-inch diameter Hercules™ Piles with a proprietary tip engineered specifically for the region’s soil profile. Each pile utilized 18-inch and 32-inch helices, configured in groups of 3 to 6 piles per pier cap to distribute the load effectively.
The piles were driven to depths ranging from 100 to 120 feet, penetrating dense glacial till, with each pile designed for an ultimate capacity of 800 kips. To reach these depths, pile sections were field-welded in 20- to 25-foot lengths, maintaining structural integrity throughout installation.
The piles were installed using a CAT 349 excavator paired with a 230,000 ft-lbs PierTech drive head to generate the torque required for the dense soils. The Hercules™ system allowed the contractor to advance through the glacial till without the noise, vibration, or extensive excavation typical of driven or drilled foundations.
Static and dynamic load testing was performed to verify performance, with all piles meeting or exceeding the engineer’s capacity requirements.
PierTech’s Hercules™ Piles provided:
The Wesleyan Church in Mitchell, SD was adding a 30,000 square foot addition to their current building. The construction would include a basement and two additional levels above the basement. The soil conditions presented a challenge for the crew. The extremely wet and soft soil could not bear the weight on the new construction. By using a helical pier system, they were able to secure the column loads. The piers were installed at a depth of 21 feet in load bearing soil.
Project consisted of flattening the bridge deck and adding architectural stone to the abutments and parapet walls. The revisions to the bridge deck plus the new masonry required the addition of helical piers to increase the load capacity of the abutments. Work also included shoreline improvements and resurfacing of the asphalt pathways leading to and from the bridge.
The PierTech helical piles consisted of: 4– 3 1/2″x10’x12″x.475 Helical Piers. Pile design 25 kips compression load.
Multi story commercial building and parking garage in the downtown Denver area. This development site required a quick, high capacity solution. The PierTech Hercules Pile was brought in to satisfy the project demands.
The PierTech Hercules piles consisted of: Compression: 500 5 1/2”O.D.(0.361wt) X 40’ long with 19” X 3/4” thick helix. Pile capacity of 170 tons- compression. Also; 500 4 1/2”O.D.(0.337wt) X40’ long with 16” X 3/4” thk helix. Pile capacity of 90 tons- compression. Tension: 100 – 5 1/2” O.D.(0.361wt) X 40’ long with 4 19” X 3/4” thk helix. Pile Capacity of 190 tons- tension. Also; 100 5 1/2 O.D.(0.361wt) X 40’ long with 3 16” X 3/4” thk helix. Pile capacity of 90 tons- tension.
The PierTech Hercules piles were installed in multi-cluster configurations, both compression and tension. These high capacity helical piles were installed to an average depth of 40 feet and terminated on a bedrock strata. 1200 piles were installed using 80K and 60K PierTech drive heads. Once the pile installation was complete, the clusters were tied into pile caps and the foundation was poured
This residential project required a quick and permanent solution to the foundation settlement problem. Helical piles were needed to stabilize the structure built on poor soil. The PierTech helical piles and TRU-LIFT bracket were brought in to satisfy the project demands.
The PierTech helical piles consisted of: 50 – 2 7/8” (0.217wt) X 8”, 10”, 12” Helix 3/8” thk 21’ long. Pile design 50 kips compression load.
The PierTech helical piles were installed around the perimeter of the foundation at approximately six foot on center. These galvanized helical piles were installed to an average depth of 21 feet and terminated in load bearing strata. 50 piles were installed using 12k PierTech drive head. The house was raised to allow for pier installation and lowered once complete. Once the pile installation was complete, the TRU-LIFT bracket was used to stabilize the foundation.
Multi-story commercial building new construction – New Jersey. On the shore line a construction site required a quick and vibration free solution to achieve high capacity loads . PierTech’s Hercules piles were brought in to satisfy this requirement.
The PierTech Hercules Piles leads were 7” (0.362wt) x 25’ pipe shaft with a 26” O.D., 1” thick helix. The extensions were 7” (0.362wt) x 20’ pipe shaft. 120 ton capacity per pile.
The PierTech Hercules piles were installed in clusters of 3 and 4. These high capacity helical piles were installed to an average depth of 60 feet and terminated on a rock-gravel strata. They were installed using a high flow excavator with a PierTech specific quick connect unit. 446 piles were installed using a PierTech 100k drive head. Once the pile installation was complete, the clusters were tied into the pile-caps and the foundation was poured.
Minnetonka Wetland Nature Preserve boardwalk project.This design build development required a quick, vibration-free solution that would not disturb the wetland surroundings. PierTech Systems helical piers were brought in to satisfy the project demands.
The PierTech helical piles consisted of: 230 2 7/8” (0.260wt) X 8”, 10”, 12” Helix 3/8”thk 20’ long. Pile design 20 kips compression load.
The PierTech helical piles were installed in pairs of two over 1600 linear feet. These vibration free helical piles were installed to an average depth of 20 feet and terminated in load bearing strata. 230 piles were installed using a 12k PierTech drive head. Once the pile installation was complete, cross bracing was attached to each pair and the boardwalk was assembled on top
The University of Minnesota Landscape Arboretum. This project required 1200 feet of decaying boardwalk to be replaced and elevated above original position on top of bog to lengthen the life and strength of the lumber. New boardwalk would also be higher to protect from freeze/thaw cycles and widened for better traffic control.
The PierTech helical piles consisted of:
200 2 7/8” (0.260wt) X 8”, 10”, 12” Helix 3/8”thk 7’ long. Pile design 10 kips compression load.
Boardwalk layout called for 12’ board sections, and as little disturbance of bog as possible. 2 piers were installed every 12 feet. Once pier locations were marked, board was fitted for piers and new piers were installed through old boardwalk lumber with articulating 8K5 drive head. Once required psi of 800 was reached, the piles were terminated in load bearing soil, at a variety of depths, from 14’ to 52’, old lumber was torn out and replaced one section at a time. Support beams were then secured to piles with saddle brackets. Bog was not disturbed.
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