Helical anchors are a factory-manufactured steel foundation system consisting of a central shaft with one or more helix-shaped bearing plates, commonly referred to as blades, welded to the lead section. Extension shafts, with or without additional helix plates, are used to extend the anchor into competent load-bearing soils. Helical anchors are advanced (“screwed”) into the ground with the application of torque.
The terms helical piles, screw piles, helical piers, helical anchors, helix piers, and helix anchors are often used interchangeably by specifiers. However, the term “pier” more often refers to a helical foundation system loaded in axial compression, while the term “anchor” more often refers to a helical foundation system loaded in axial tension.
(This article comes from AquaGuard Foundation Solutions edit released)
Helical Anchors (also referred to as tiebacks) provide lateral stability to foundation walls and retaining walls with unbalanced earth pressures. Helical anchors can be installed with hand-held equipment, mini-excavators, skid steers, backhoes, trackhoes, or crane-supported rigs so the anchors can be installed in almost any application. This versatility, along with the ability to immediately load and test the anchors, make helicals a convenient and economical solution for a wide variety of projects.
- Predictable capacity
- Helix blade configuration selected to achieve design embedment and capacity
- All-weather installation
- Can be installed in areas of limited or tight access
- Installation does not generate spoils
- Clean installation with no messy grout
- Load tests can be performed immediately following installation
- Available with optional hot-dip galvanizing for added corrosion protection
(This article comes from AquaGuard Foundation Solutions edit released)
Mobile homes are relatively lightweight when compared to conventionally built homes. For this reason, a mobile home must be secured — or tied down — to the ground to avoid shifting or tipping over in high winds. Made from steel rods, helical anchors have a circular plate at the bottom that allows them to be screwed into the ground. The anchors can be used to tie your mobile home to the ground and keep it secure during storms.
- Dig a hole next to the mobile home to a depth that is two-thirds the length of the helical anchor being used. Ensure the hole is at a 10-degree angle facing away from the home and is not so far away from the edge of the home that the skirting or sidewall will not cover it.
- Insert the anchor into the hole with the helical plate facing downward. Insert a 2- or 3-foot length of metal pipe through the hole in the bracket at the top of the anchor shaft. Use the pipe for leverage and twist the anchor into the hole in a clockwise direction until the bracket at the top of the anchor is at ground level. Slide the pipe out of the bracket and remove it.
- Replace the soil removed from the hole in 6-inch depth increments. Tamp the soil down with a tamping rod. Continue adding soil to the hole and tamping in the same fashion until the hole is fully covered.
- Measure 3 to 4 inches away from the anchor bracket protruding from the ground toward the mobile home. Pound an anchor stabilizer into the ground at this point with a hammer until only the top of the stabilizer is visible.
- Insert a bolt through the loop in the end of an anchor strap and the mounting hole in the anchor bracket protruding through the ground. Place the hook in the opposite end of the strap over the frame of the mobile home.
- Tighten the bolt on the strap and bracket with a wrench until the strap becomes taught and the anchor is pulled against the stabilizer you pounded into the ground earlier. Tighten the nut on the opposite end of the bolt.
Tips & Warnings
- Normally, a mobile home is anchored before skirting is installed. If skirting has already been installed, it must be removed in the area where the anchor will be installed.
- Although anchors can be driven into the ground electrically, two people are required. Machines for this purpose may be available from your local tool rental store, but be sure to read all of the precautions and warnings of the machine before using it.
(This article comes from eHow editor released)
Immediate pull testing of helical tieback anchors after installation serves as a check on design procedures and eliminates deflection at working loads.
No delays because there is no grout
- Typical production rate of 30 to 40 per day for installing and testing
- No holes to drill
- Cuts labor and equipment costs
- Can save 30% while obtaining high anchor-load capacities
Solves construction problems
- In cohesive soils, no belled and/or long sockets
- In non-cohesive soils, no casings or grouted sockets
- Bearing mode (not friction mode) anchors
- No de-watering for below-water-table applications
(This article comes from CHANCE editor released)
Ground screw is a large screw, using special machines will drill into the bottom, can be achieved with the concrete base the same strength and tensile force. The cost of this method is more lower than the traditional concrete method, and the disintegration of easy to remove, and can be repeated use. Therefore, now the solar power generation equipment are used this ground screw to stability the foundation.
Keystone Ground Screw is specially developed for the maximum flexibility in designing for both residential and commercial solar mounting system, which can be applied to various soil conditions.
1) Quality Guaranteed: Treated with a layer of zinc, ground screw enjoys a longer life span with better corrosion resistance.
2) Versatile mechanical innovation: Unique structural design ensures a much better pull-out and load bearing capacity.
3) Application is wide that can be used in all types of soil and all type of structures.
4) Easy Installation,remove and relocate: Highly pre-assembled structures with minimal components and the adaption of hydraulic pile hammer ensure a quicker and easier installation with less labour cost, which takes 2 minutes on average only to ram a ground screw.
5) Environmental- friendly application: Compared with concrete bases, ground screws can be fully recyclable and cost effective, while produce little waste and can easily be removed.
Ground screws when used directly into the inner of earth，without digging, backfilling process, does not destroy the surface. On the grass, planting belt also easy construction, no need of transplant trees, flowers etc..
(This article comes from GongChang editor released)
Helical anchors have been in use for more than 170 years. In 1838 a lighthouse was built upon helical piers designed by an Irish engineer, Alexander Mitchell. Sporadic use of helical piers has been documented throughout the 19th and early 20th centuries mainly for supporting structures and bridges built upon weak or wet soil.
When hydraulic motors became readily available in the 1960’s, which allowed for easy and fast installation of helical piers, their popularity flourished. Electric utility companies began to use helical piers for tie down anchors on transmission towers and for guy wires on utility poles.
Helical piers are ideal for applications where there is a need to resist both tension and axial compression forces. Some examples of structures having combination forces are metal buildings, canopies and monopole telecommunication tower foundations.
Current uses for helical piers include underpinning foundations for commercial and residential structures, foundation repair, light standards, retaining walls tieback anchors, pipeline and pumping equipment supports, elevated walkways, bridge abutments, and numerous uses in the electric utility industry. Many times helical anchors are the best solution for your foundation repair project due to one of the following factors:
- Ease of Installation
- Little to No Vibration
- Immediate Load Transfer upon Installation
- Installed Torque Correlates to Capacity
- Easily Load Tested to Verify Capacity
- Installs Below Active Soils
- All Weather Installation
- Little to No Disturbance to Jobsite
(This article comes from Earth Contact Products editor released)