The 702-mile-long Kuskokwim River in Southwest Alaska is the longest free-flowing river in the United States. Situated about 50 miles upriver from where it flows into Kuskokwim Bay is the community of Bethel. With a population of approximately 6,500 residents, it’s home to Bethel (Regional) High School.
Bethel High School is comprised of about 540 students and 34 staff members and serves grades 7-12. The facility in which it’s housed needed more room, including a cafeteria and space to utilize for program events. Therefore, a 5,000 square foot addition was built.
The addition was constructed on silty sand with permafrost 26 feet below grade. To handle the project’s particular design, the services of PierTech Systems were employed. 31, 8.675 outside diameter (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 helical piles were designed for an allowable capacity of 120 kips compression load. Because PierTech manufactures each Hercules helical pile to the exact specifications of each project, the ones installed at Bethel High School were custom made for the project.
A total of 62 PierTech Hercules Piles were installed in a period of about six weeks using PierTech 70K and 100K Drive Heads. The average depth for the piles was 35 feet, and each one was torqued out at approximately 50,000-foot pounds. After the piles were set, thermosyphons and monitor tubes were drilled and placed. This was done to ensure the permafrost stays frozen, and the building doesn’t settle. The Hercules Pile gives customers a dependable, high-strength solution that won’t corrupt the soil in which it’s installed. Consequently, the piles can last for many years.
Projects like the Bethel High School expansion are a perfect fit for PierTech’s industry-leading, high-capacity Hercules Pile. The patented product is engineered from the ground up to be a superior product. Also, it can be used as a replacement for other deep foundation solutions, including pipe piles, augercast piles and micro piles. It utilizes a smaller footprint than other solutions, which is especially beneficial for projects with access issues. Plus, many groundwork contractors already have the heavy equipment and only need is a drive head to start installing Hercules Piles – a perfect fit for PierTech.
Some construction projects require a solution that negates possible effects from vibration on surrounding foundations. When installed correctly, the Hercules Pile produces virtually no vibration. In fact, the noise emanating from the installation is mostly the sound of the machine used to turn it into the ground.
The Hercules Pile is installed exactly like any other helical pile – it’s turned into the ground using a high-flow excavator and a three-to-five-man crew. PierTech pre-engineers each pile to exact specifications, so they’ll turn into the ground both accurately and easily. There’s no need to pour concrete, dig holes or wait for curing, and installation can be completed in any weather. Therefore, the installation process goes smoothly and quickly, meaning up to 20 Hercules Piles can be placed in a single day.
Load capacity is another area in which the Hercules Pile excels. It can support up to 500 tons. Hence, it’s enough to support a 10-story building application. It’s available in 4″-48″ shafts.
Many of the custom-made Hercules pile can be equipped with our patented connections and can be galvanized if requested. In addition, the piles can be grouted and produce no overburden.