What Are Helical Piles?

Helical pilings are a form of manufactured deep foundation piles. As indicated in the name, screw/helical piles contrast from supplementary deep foundations and are most significant for having corkscrewing helices along their steel shafts. Helical piles are vastly different than historical foundation pilings, which have a relatively uniform shape like steel/concrete driven piles and micropiles.

Also named screw piles, they serve as options for deep foundations support. These piles convey a structural load deeper into robust and less compressible materials by using segmented extensions. Screw piles are rotated into the ground to reinforce new structures or to underpin surviving structures that have settled. Helical pilings can be used in most foundation applications throughout Florida that call for a driven pile, micropile, and augercast piling.

How Are Helical Piles Constructed?

Helical piles are constructed of hot dipped galvanized steel to shield it from rust. All CFS piles are usually round hollow shafts or solid square piles manufactured from ASTM steel. The piling is offered in a variety of diameter and square shafts contingent on engineer’s design specifications. A significant element of piling engineers pile design is also the geological content of subsurface soils.

Square Helical Piles Vs. Round Piles

Customarily, square shaft helical piles can be used in both tension and compression applications. Round shafts are more commonly used for compression and have a greater section modulus, resisting bowing in flimsier soils. In Southwest Florida, we use primarily round shaft for new construction and square shaft for grouted micro piling and seawall tiebacks.

Helical Segments & Extensions

The seven-foot helical segmented lead may have single or multiple helical blades, also referred to as bearing plates. These fins vary in size, shape, and quantity. The helix plates are welded to the main pile shaft to insure proper blade separations. Our extensions are additional sections which drive the helical lead deeper into the ground to secure capacity.

Why Are Screw Pilings Used?

Screw piles have been in existence for many years but are relatively new to Florida. They’ve traditionally been used in other parts of the country building railways, providing runaway support as well as major engineering projects. The best advantage of screw piling is its versatility and ease of installation. Coastal Foundation Solutions can install high-capacity screw piling with compact equipment and in confined locations relatively quicker. The pile process involves less spoils, low noise levels and no vibration levels to affect neighbors.

What Is The Purpose Of A Helical Pile?

Screw piles are selected for their performance in conditions where deep foundations are essential or anywhere construction is involved near other structures. These piles tend to be the most cost effective and practical option while maintaining minimal environmental impact. Contrasting to most foundation pile installations, helicals present diverse benefits over conventional foundation designs and anchor techniques. Unlike augercast piles which require time for concrete to cure, screw piles are load bearing straightaway after installation. Our Florida piles are ultimately utilized for home addition projects, new swimming pool/hardscapes, marine applications, and underpinning.

How Are Helical Piles Installed In Florida?

The installation technique of a helical pile is quite simple. Helical piles are rotated into the ground, much like a large lag bolt is screwed into a large wood timber. Coastal Foundation Solutions utilizes a competent size excavator with a hydraulic anchor drive to employ the substantial torque that is required to screw a helical pile into the ground. The pile installation process is vastly different for each project in our coastal area. The specialized equipment for a 100-year-old wooden structure is quite different than a modern 5-story modern concrete office building.

Coastal Foundation Solutions possesses a large array of piling installation equipment from 50-ton excavators, micro-crawler rigs, and dedicated customized pile insertion gear. Once the pile has reached the target capacity it remains permanently in place and a galvanized termination pile cap is attached. The protruding pile acts as reinforcing and provides the connection to the new structure above.

How Much Weight Can A Helical Support?

The critical aspect of helical pile design is accurate structural and geotechnical engineering. Every pile project installation is unique, requiring customized helical pile designs and diverse load bearing capacities. Helical pile capacities vary based on multiple factors: the design of the piling, the soil conditions, and the depth piling must travel to secure torque. An exceptional single helical pile load capacity may hold up to 500 TONS of weight, but in aggregate the capacity may be extraordinary higher. Please consider that Tension forces are those that draw materials apart and Compression influences is the one that compresses material together.

What Is The Average Lifespan Of A Helical Pile?

The life span of helical piles in Florida will contrast depending on the subsurface nature of soil. The dryer the soil, the screw piles will have exceptional longevity. Coastal screw piles can indeed last between 100 and 150 years. The tropical soil moisture content shall have the utmost impact on how well your screw piles will do once installed. Coastal Foundation Solutions provides our clients with hot dipped galvanized steel piling. The round shaft screw pilings have internal and external galvanized coating, thus providing for a multi-generational foundation. Screw anchors have been used for lighthouses, roads, railroads, and telecommunication for over 200 years.

What Size & Length Of Helical Will My Project Require?

In Florida, the depth to which coastal helical piles need to travel depends on numerous factors, including the soil type, load capacities, and varying site conditions. In typical installations, screw piles are engineered to be put into a depth where they can support the vital load demands. The distance at which screw piles are installed is essential, as the load-bearing helix plates are what takes the weight of the structure and conveys it into the soil. The helical pile, with multiple helix’s, is positioned along the pile shaft, which lets it encounter solid soil deep below the surface. The screw piles depth may fluctuate from a minimum of 14 feet to over 70 feet, depending on the engineer design requirements. The conditions will specify a torque and load capacity in which the pile must hold.

Our screw piles are installed with a digital torque indicator which dictates applied torque capacity. If the desired engineered capacity has not been attained the helical pile must be driven further into the ground by adding additional extensions. The extensions shall travel deeper until the soil condition is solid enough to meet this engineered requirement.

Site Investigation & Soil Analysis

A geotechnical investigation is imperative before you commence any type of construction or building project. Considerable structural damage can be a result when homes are built on poor foundations. The strength of these foundations commences with the type of soil the footings are placed upon. Moisture content in clay soils can swell or shrink with dampness changes and settlement can ensue due to compressed soil or fill.

Geotechnical analysis is essential prior to contemplating house designs or construction plans. Soil conditions can dictate the foundation design and cost. The geotechnical report includes a site investigation of the subsurface soil and lime-rock properties that exist beneath the surface of the property. The soils exploration is performed to ascertain the engineering properties of how the subsurface elements and foundations will interact with the proposed construction. A geotechnical soil evaluation report encompasses a subterranean site analysis, which is then tested and verified by a geotechnical engineer. The principal reason for the test is to comprehend how ‘sensitive’ the soil is. Soil boring evaluations identify incompatible subsurface soil conditions that have the potential to trigger settlement of the helical pile footings and concrete foundations. The assessment is also prepared to confirm that there are not any physical conditions or organics that could impair or disrupt the proposed construction. Our screw piles are installed with a digital torque indicator which dictates applied torque capacity. If the desired engineered capacity has not been attained the helical pile must be driven further into the ground by adding additional extensions. The extensions shall travel deeper until the soil condition is solid enough to meet this engineered requirement.

What Are The Pros & Cons Of A Helical Installation?

Screw or helical piles are increasing in popularity in Florida, especially after Hurricane Ian. Design engineers have witnessed their exponential value due to survival of helical pile structures after recent hurricanes. In short, helical/screw piles are a very dynamic deep foundation system and this versatility creates a long list of positive benefits, including but not constrained to:

  • Versatile installation of around 40 seconds per foot of pile on a conventional project
  • Piles may be loaded to capacity immediately – no curing
  • Helical Piles are exceptionally clean–no predrilling or concrete spoils to remove, the pile is simply rotated into the ground.
  • Low vibration and exceptionally quiet installation shall not disrupt wildlife or the family next
  • Pile installation may be accomplished with smaller, equipment than traditional
  • Placing extensions on allows the piling to reach competent soils fast and cost-
  • Square shaft helical piles can pass through fractured lime rock layers without
  • Helical/Screw Work well in tension and compression
  • Firsthand relationship between installation torque and capacity means predictable expected
  • The capability to uninstall a pile indicates a pile may be relocated if obstruction is
  • Valued engineered piling allows field adjustment of design pile that is effective as well as proficient
Disadvantages Of Helical/Screw Piles?

There is nothing magical about helical piles in the world of deep foundations. Below are some of the shortcomings or limits with helical piling:

  • Helical piles are a relatively new piling for structural or geotechnical engineers in
  • Standards and engineered principles are available but not always utilized by older
  • Screw piles, helical anchors and ground screws provide confusion to the marketplace, the general population is not aware of their endless possibilities.
  • Helical piles do not function when there is impenetrable strata) close to surface
  • Measurement of torque values and capacity when pile encounters refusal requires load testing in this
  • Performance may be greatly influenced by the ethics of the helical pile contractor, their experience, technical knowledge/engineering pedigree and equipment utilized.
  • Due to smaller shafts compared to other pile options helical piles provide lower resistance to lateral and/or bending forces.
  • Very dense soil layers are difficult for round shaft helical piling to Consequently, square shaft piles are usually required to assist in endeavoring to penetrate hard substrate.
  • Helical piles cannot penetrate solid lime rock in Florida
Are Helical Piles Required In Florida?

There is new testimony to the value of helical pilings installed in Florida prior to hurricane Ian. Coastal Foundation Solutions has installed thousands of pilings to date in our coastal areas. Helical pile projects include swimming pools, hardscape walls, structural concrete slabs, cell tower support, underpinning existing foundation, reinforcing existing foundation for mutistory structures, marine applications and the list continues. Helical piles are galvanized steel pipe piling that are used to support new and existing structures by securing the load into competent ground, much like a typical driven pile. The environmentally recyclable system promotes a clean and swift installation process, with no spoils to maintain or debris removal.

How Do You Raise A Structure That Is Sinking?

Coastal Foundation Solutions provides structural components which become attached to the foundation of a structure. A helical piling is rotated into the ground to competent soil and a HDG custom foundation bracket is attached to the grade beam or footer pad. A specialized hydraulic lifting jack is temporary installed to raise the structure. The hot dipped galvanized bracket becomes a permanent component of the footer and maintains the structure elevation.

Helical Underpinning Pilings

Coastal Florida Homes may experience settlement that leads to sunken foundations. Primary visible indications of this occurring at your home or business may include fractures appearing on exterior walls, windows, or doors difficult to open and sliding glass doors which won’t open easily. Underpinning provides additional support to existing foundations in residential or commercial buildings that are unable to safely support existing loads. Helical piles are rotated into the ground and a bracket is attached to a concrete footer. These piling are required when ground descending has caused foundations to sink. This is frequently prompted by moisture changes in the soil, roof runoff, or deteriorating retaining walls.

How Much Space Is Required For Helical Pile Installations?

Screw/Helical piles may be used in all types of confined locations, as tight as a walk-in shower. Coastal Foundation Solutions has a fleet of specialized equipment that may be used in very small places and larger excavators for unrestricted access areas. Our equipment and installation drives are relatively compact as compared to other pile installation methods.

What Is The Torque Capacity Of A Screw Pile?

Torque is the rotational force required to install a helical pile. Helical pile deigns require varying degrees of torque based on engineered capacities in tension or compression. Denser soils, create greater torque and cohesiveness soils develop lower torque. In addition, square shaft piles have a KT factor of ten and round shaft piles commence with a KT factor of 9 for 3” pipe.

What Is A KIP?

Kip is an engineering abbreviation for Kilo-Pounds, it represents 1,000 pounds. This is a common unit of measurement in calculating compression and tension loads.

How Long Will Helical Piles Last In The Earth?

We only utilize hot dipped galvanized material and components. Florida’s tropical environment and harsh marine seawater, permeates into our groundwater, thus creating additional caustic potential. The galvanizing process provides superior defense from rust and corrosion with a life expectancy of 100 years.

Why Are There Only Flights On The First/Lead Segment?

The helices spiral into the ground first developing torque as it travels deeper into the substrate thus providing bearing capacity. The helix flights are what supports the engineered designed load requirements. This is commonly referred to as compressive capacity or true end bearing capability.

How Are Screw Piles Put In The Ground?

A hydraulic gear motor mounted on a mini-excavator or 50,000# excavator is used to screw the hot dip galvanized helical pile into the soil. Installation torque is monitored to secure engineered load capacities. A steel termination plate is then welded or bolted on top of the pile and encased into the new concrete foundation.

How Many Helicals Are Installed For A Standard Sized Florida Pool?

If you are a pool contractor, or engineer designing swimming pools, helical piles play a crucial role in pool foundations. The significance of ensuring the soil is as stable and secure with the use of helical pile anchors. Water in a swimming pool project can place substantial weight on the concrete pool foundation. As a rule of thumb most standard pools contain approximately 10 to 16 helical piles.

Can You Install Helical Piles In My Seawall?

Helical Tie-Back anchor systems are custom tailored foundation support system solutions implemented to solve the unique challenges coastal structures encounter. Coastal Foundation Solutions inserts helical tieback anchors in seawall and bulkhead construction which provides excellent lateral stability and support. The screw anchors may be used throughout Florida in conjunction with steel sheet piles, vinyl, or concrete walls.

Our assortment of specialized equipment allows us to preform installations in confined areas with confined accessibility, in various Florida coastal conditions.

Do Helical Piles Need To Be Filled With Concrete?

There are isolated situations in Florida where helical piling shall have a concrete grout added to the perimeter of the piling. This is predominately a square shaft pile, called a helical micro pulldown piling. In some instances, the interior of a round shaft pile may be filled with grout to strengthen the bolted connection points.

How Much Does It Cost To Install Helical Piles?

A screw pier installation cost varies based on the application of the pile and the engineered capacity. In addition, there are other factors which dictate the cost of a new construction pile in Florida. On average, a standard 8”/10”/12” round shaft helical pile installed to 21 foot is approximately $1,260.00 installed. As a rule, the smaller the quantities of piles the higher the cost. This cost is specifically for new construction piling utilized in new structures. Underpinning screw piles are higher in installation cost due to higher material and labor cost. Most homes require 8 to 10 piers, and the cost is generally $1,500.00 to $2,000.00 for underpinning piles.

How Do I Get A Design & Screw Piling Quote?

Securing a formal proposal for your project is relatively easy and painless to secure. Coastal Foundation Solutions requires a soils report from your geotechnical engineer and construction plans from your architect/structural engineer. Our estimating staff will promptly provide you with a comprehensive proposal outlining all aspects of your helical pile project.


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