When undertaking a construction project that requires a foundation, it is critical to have a finished product that is solid and secure, so the building does not settle over time. When that structure is built on a slope, everything becomes exponentially more difficult to complete. With that said, helical piles have simplified foundation building, not only in the design, but also in the construction process, especially for sloped construction.
When we look at a foundation using Techno Metal Post helical piles, each pile can be customized for the specific needs of the project. The engineering that goes into the design considers compression, tension and lateral forces that will be placed on the pile once installed. Our inhouse engineers translates these forces into the selection of the pile shaft diameter and the helix diameter, as well as the number of piles needed and the soil pressure they need to be installed within. Our engineering team ensures a professional, code approved, and safe foundation solution for every project. Once each pile is successfully installed, the array serves as a complete structural unit, each doing their individual job displacing the overall load. Combined with a custom bracket system, each pile connects to the structure’s base material (which is either steel, concrete or wood) and is locked in place. There is no digging or compaction work required with helical piles.
When you introduce a sloped surface, there are always concerns about lateral stability. Should this be a concern on your project (slope or not), a helical pile foundation can be adjusted easily to factor in this additional force. Some of the helical piles can be constructed to have a second helix. A battered pile (which means installed at an angle into the slope) can be installed next to the vertical pile shaft and welded into the main bracket system. If the structure has a portion above the ground, then the beams and posts for the main structure can be further strengthened directly using angled bracing, as shown in the photo above.
The design of any foundation looks great in drawings but eventually it needs to be built on site. Traditional footings and foundations require excavation, forming work, setting rebar, and pouring / curing concrete. This takes time to plan and execute and then there is the time required to achieve the strength in the concrete before loading. When using a basic helical pile foundation design, all this is eliminated, and a single install machine and crew can complete the pile installations needed for even the toughest foundations. Since the machines are small and compact, a small platform with adjustable posts can be used to create a flat surface for the installation crew to complete the pile installs safely.
How Deep do the helical piles need to go?
Concrete foundations will have a minimum depth (below the frost line for temperate climates) and be wide enough for the appropriate footing width to displace the structural load. For helical piles, each pile will go deep enough so that the helix is locked into competent soil below. This depth could be well below any equivalent concrete foundation as competent soil is confirmed by measuring the torque off the drill head from the installation equipment, which is then converted to a bearing capacity. Once the desired bearing capacity is reached, the helix receives a final turn and is then locked into position. This ensures each pile is secured in the right bearing capacity below.