In Bethel, Alaska, the Bethel Regional High School is expanding and adding a cafeteria. The school has not had one since it was built, and it will also use the addition for program events. The addition is about 5,000 square feet, being built on silty sand with permafrost 26 feet below grade. PierTech Systems helical piers were brought in to satisfy the project demands.
31, 8.675 OD with a 14" and 18" Helix (¾" thick) and 31, 12.75 OD with a 20" and 24" helix (¾" thick) were used on the project. The piles were designed to an allowable capacity of 120 kips compression load.
The average depth for the piles were 35’ and they were torqued out at approximately 50,000-foot pounds. The installation for the 62 piles took approximately six weeks. After pile placement, thermosyphons and monitor tubes were drilled and placed to ensure the permafrost will stay frozen and the building will not settle. The piles were installed using the PierTech 70K and 100K Drive Heads.
The project was at Mount Olivet Lutheran Church, located in Minneapolis, Minnesota. The piles were installed next to the existing structure to add an auditorium addition to the church. Helical piers were selected due to poor soil conditions and tight working conditions at the site. Due to the depth of installation, the helical pile leads and extensions were manufactured in 15-foot sections to save time and material costs.
The PierTech helical piles consisted of: (90) 2-7/8″ X .362 Wall Cross Lock Patented Helical Pile Connection with 8-10-12 helix configuration, (370) 2-7/8″ x.362 Wall x 15 ft, Galvanized Cross Lock Extensions, (90) 2-7/8″ x .362 Wall x 7 ft Galvanized Cross Lock Extensions, and (90) 2-7/8″ Galvanized New Construction Brackets. The piles were designed to an allowable capacity of 45 kips compression load.
These helical piles were installed to depths between 65 and 90 feet deep and in 15-foot sections. The piles were installed using a PierTech 12K Drive Head.
In Williston, North Dakota, the Williston Water Treatment Plant is expanding, doubling the plant capacity of the people it can serve. The poor soils on the site required a quick vibration-free solution that would not disturb the surrounding structures. PierTech Systems helical piers were brought in to satisfy the project demands.
300, 4.5” OD PierTech Hercules piles, with a 10″, 12″, and 14″ helix configuration, were used on the project. The piles were designed to an allowable capacity of 65 kips compression load.
These high-capacity helical piles were installed to an average depth of 45 feet and terminated on a claystone/shale load-bearing strata. The piles were installed using the PierTech 40K two-speed drive head.
The Roberts Garage project was located in Fargo, North Dakota. A 5-story elevated parking garage was being constructed on poor soils. The construction site required a minimal noise and vibration free solution due to the sensitivity of surrounding foundations. PierTech’s Hercules piles were selected to satisfy this requirement.
The PierTech Hercules Pile leads were 10-¾” OD Hercules piles – PierTech’s proprietary tip, with an 18” and 24” helix. The Piles were designed to an ultimate capacity of 800 kips compression load. Field static and dynamic load tests were performed to verify the capacity
The PierTech Hercules piles were installed in groups of 3 to 6. These high capacity helical piles were torqued into a hard-glacial till at an average depth of 100-120 feet. Over 100 piles were installed with a Cat 349 excavator, using a PierTech 230k drive tool. Pile sections were field welded by the contractor in 20-25 feet sections. Pier caps were formed and concrete was poured around each pile group.
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.