Pros and cons of foundations on screw piles

Screw pile-supported foundations are becoming more and more common in the construction industry because of their special benefits and ability to work with different types of soil. Screw pile foundations offer a quicker and less disruptive installation process than traditional concrete foundations, which call for prolonged excavation and curing times.

The adaptability of screw pile foundations is one of their main advantages. They can be employed in a variety of settings, including temporary structures like event stages and residential and commercial buildings. Their capacity to offer steady support on a variety of soil types, including clay, sand, and even marshy areas, accounts for their adaptability.

The minimal environmental impact that screw pile foundations have during installation is another benefit. Typically, screw piles are installed using hydraulic machinery, which minimizes noise, soil disturbance, and overall construction waste, in contrast to concrete foundations that require heavy machinery and excavation.

But there are other factors with screw pile foundations that should be carefully considered. Their load-bearing capacity, which varies based on soil conditions and pile design, is one of the primary concerns. In order to calculate the proper size and depth of screw piles needed, engineers must precisely evaluate the soil’s bearing capacity.

Furthermore, screw piles can be more or less cost-effective depending on the situation, even though they can be installed more quickly than traditional foundations. Various factors, including soil composition, project dimensions, and ease of access, can impact the total expense and occasionally render screw pile foundations more costly than traditional techniques.

In summary, screw pile foundations are a cutting-edge substitute for conventional concrete foundations, providing benefits like quick installation, little environmental effect, and adaptability to various soil types. To make sure they are appropriate for a given construction project, load-bearing capacity and cost-effectiveness must be carefully considered.

Pros	Cons
1. Quick installation, reducing construction time.	1. Costlier compared to traditional foundations.
2. Minimal disruption to surrounding landscape during installation.	2. Requires skilled installation to ensure load-bearing capacity.
3. Suitable for areas with poor soil conditions, like clay or sand.	3. Vulnerable to corrosion in certain soil types.

Foundation on screw piles

Screw piles are a type of supporting structure that resembles a network of submerged metal pipes with spiral blades welded to the bottom (see photo below). They perform a cutting function akin to that of screws.

The blades cut and run parallel to the support nodes, and the barrel’s pointed conical tip makes it easier to penetrate the ground.

The load on the blades and the frictional force between the pipe’s side walls and the ground keep the submerged support stationary. Installation is done in accordance with a predetermined plan, creating a t.n. pile field that guarantees even load distribution throughout all shafts.

Following immersion, the upper sections are cut to create a flat surface and secured with a grillage, a load-bearing belt.

It gives the walls a solid foundation and distributes the weight evenly across the pile system.

The grillage operates similarly to a strip foundation, but it is supported by the upper ends of the vertical rods rather than the ground. After installation, hollow pipes are filled with compacted concrete to strengthen the structure and protect it from potential lateral loads.

Immersion is not necessary for screw pile installation until they come into contact with thick soil layers. Being a hanging type of pile, they can hold the building quite reliably with enough deepening.

Advantages and disadvantages

Among screw piles’ benefits are:

• High installation speed.
• Possibility of manual installation, which allows you to work in close proximity to finished buildings.
• The cost of screw piles is much lower than other types of foundation.
• Reusable. If necessary, the piles can be removed and used elsewhere.
• No excavation required for installation.
• It is possible to build on slopes or folds of the terrain.
• You can do without the use of complex equipment.

The drawbacks consist of:

• Operating conditions promote corrosion.
• The use of screw piles in regions with high seismic activity is prohibited.
• Immersion in rocky ground is not permitted.
• The use of screw piles on loose or slightly carrying soils that do not form sufficient lateral support requires additional examination and clarification of the depth of immersion.

Manufacturers tend to hide the majority of the flaws, so it’s important to fully comprehend the characteristics and features of the design.

Types of supports

Let’s examine the various kinds of screw supports that are employed in contemporary building:

By area of application

This kind of foundation has far more applications than one might initially think.

The following situations see successful application of screw piles:

• Capital construction.
• Individual residential construction.
• Bridges, piers, other hydraulic structures.
• Load-bearing power line supports, masts, etc.P.
• Hangars.
• Greenhouses.
• Fences or enclosures, etc.d.

The range of applications for this kind of base has significantly increased due to its growing popularity, and this process is still ongoing.

Dimensions

Various diameters of steel pipes are utilized. The most popular pipe size is 108 mm, which has good ground penetration and a respectable load-bearing capacity.

Although the entire range of pipe diameters is between 57 and 219 mm, thicker supports are also utilized in certain situations.

Because of the difficulty of immersion, pipes longer than 159 mm are not utilized in the construction of private homes.

There are numerous choices for the pipes’ length. Sizes ranging from 1650 to 9000 mm are available, provided the proper conditions are met.

The length of the barrel should increase with decreasing soil strength and density.

The number of blades

There are constructions with one or more lobes. -lobed are utilized on comparatively dependable soils.

Adhesion to the soil is lost during installation if the piles are reversed or the load is exceeded.

Multilobed piles are used for responsible buildings on slightly carrying soils because they show greater resistance to potential loads.

Furthermore, reducing the barrel’s diameter through an increase in blade count makes immersion easier.

The thickness of the wall should also give the required rigidity.

Tips

During immersion, the tip bears the weight, which places some fairly tight design requirements on it.

There are:

• Welded tips. Made by narrowing the diameter of the pipe by removing wedge-shaped sections and connecting the resulting fragments into a cone. The seams are welded and a pointed end is formed. Used for relatively weak, soft soils.
• Cast tips. Made (cast) separately and attached to the pipe. Have a large thickness, capable of destroying obstacles encountered. Used on dense and complex soils.

Material of manufacture

Various steel grades are utilized, ranging from the standard St 3 to the more resilient St 20.

Durable steel grades 30 KhMA and 09G2S are used for use in highly aggressive soils with high loads and the potential for electrostatic corrosion.

Type of protective coating

Zinc coatings are thought to be the most effective. The substance itself must also have adequate corrosion resistance.

The polymer materials that were added to the piles are submerged and lose their ability to function.

They need to be updated on a regular basis and are only required to protect the supports’ exterior.

Although many engineers provide their own protective solutions, such as applying a rubber layer or using mastics, these techniques are still relatively new.

Which ones are most optimal for use in country house construction??

Without weighing the house or examining the soil, it is impossible to determine the best kind of screw piles.

The most appropriate choice, given the particulars of the construction—which include building a relatively light house with a limited number of floors—would be to use single-bladed trunks, with a diameter ranging from 57 to 108 mm, depending on the kind and state of the soil.

Since the pile has a limit, more precise information can only be obtained by surveying the area and estimating the load. For instance, the maximum load with a 57 mm diameter will be 800 kg.

For which buildings is it needed??

Screw piles are applicable to a variety of constructions. Experience from around the globe has demonstrated that this kind of foundation can function well with large, weighty, and towering buildings and structures.

However, Russia does not yet have the technology to create this foundation, so their options are typically restricted to building outbuildings or auxiliary structures. Screw piles are utilized sparingly and with reluctance for residential buildings.

For your article on the "Pros and cons of foundations on screw piles," here is a succinct and straightforward thesis statement: Modern alternatives to conventional concrete foundations are provided by screw pile foundations, which are renowned for their easy installation and low environmental effect. They can be applied in environmentally sensitive areas where traditional methods might be difficult and offer stability on a variety of soil types. Their suitability, however, is dependent on the load requirements and the state of the soil; they might not be the best choice for very heavy structures or specific soil types. Understanding the benefits and drawbacks of screw pile foundations can help determine when and where they are most useful in building projects.

Life time

Under perfect circumstances (no corrosion, soil that doesn’t harm the material, etc.).e) The support has a 300-year maximum lifespan, and an 800-year maximum if a galvanized layer is present.

Manufacturers and marketers claim this, even though they have no justification for doing so. Such claims are nonsensical because it has only been 299 years since the invention. Impacts and typical metal fatigue still exist, and ideal conditions are nonexistent.

Thus, although there may be variations in either direction, the true service life of such a foundation should be estimated to be between 50 and 75 years.

Mitchell, the man who invented screw piles, built some of the first structures that are still standing and in use today.

Is it a capital foundation or not??

Screw-in piles are strong enough to support enormous, heavy buildings or other structures. They should thus be regarded as the capital foundation by default.

A psychological imbalance develops in this situation because, on the surface, they don’t appear to be a solid support system, which is consistent with the definition of "capital."

The primary characteristic, though, is that it can be used to build residential structures.

This makes it reasonable for us to think of screw piles as a long-term kind of foundation.

How to make the right choice?

There are two steps involved in choosing screw piles:

• Determining the appropriate size and type of screw piles.
• Selecting specific products based on quality and compliance.

Almost all of the first step is completed while designing the house. Consequently, discussing him is pointless.

Typically, representatives of the business with which the contract is concluded handle the second step.

If you must make a decision on your own for whatever reason, you should consider the following information:

• The thickness of the pipe walls should not be less than 4 mm.
• Blade thickness – at least 5 mm.
• Welding quality must be as high as possible.
• Availability of galvanized layer.
• Type and quality of tip.

These standards will help you select the highest caliber merchandise.

It is best to decline to buy such piles if any of the items do not fit the specified standards.

How much does a foundation like this cost?

Let us examine the price of a screw foundation for a house measuring 6 by 6 meters. Nine piles make up the ideal configuration for a pile field.

The cost of the piles themselves as well as the installation of nine pieces (which range in price from 650 to 1100 rubles each) will then be borne by the site’s owner.

Depending on the diameter and length, it can cost up to 1200 rubles without installation or 1100 rubles with installation for a 3 meter long VS-57 (diameter 57 mm).

The cost (without installation) for a 3-meter trunk with VS-108 will be 1150 rubles with installation and 1350 without installation if you choose to use it. It is intended to encourage customers to order installation from this company by offering a discount on the purchase price with and without installation.

The foundation will therefore cost roughly 20,000 rubles. But, you must have some reserve because this amount does not account for delivery or other overhead.

Different companies may have different prices; this needs to be confirmed up front.

Brief and general installation diagram

Method:

• Pile field marking.
• Screwing piles.
• Filling pipe cavities with concrete, trimming the tops to obtain a flat surface.
• Installation of heads.
• Grillage installation.

It is advised to use specialized machinery for installation. By doing this, you can make sure that the pile is vertical and doesn’t rock when you screw, which helps to maximize your close contact with the ground. An anti-corrosion compound is used to tint the areas that are damaged during the welding process and those that are not.

For building projects, screw pile foundations have a number of benefits. First off, in comparison to conventional concrete foundations, they offer an installation process that is quicker and less disruptive. This can drastically cut down on the amount of time and money needed for construction. Screw piles can be erected in a variety of soil types, such as wet or soft soils, where conventional foundations might not work as well.

Their adaptability is an additional advantage. Screw piles can be used in a variety of applications, from industrial buildings to residential homes, and are appropriate for both temporary and permanent structures. They are a versatile option for building projects since they have a high load-bearing capacity and are simple to install or remove.

Screw pile foundations have benefits, but there are also some things to keep in mind. One issue is their initial cost, which, depending on the details of the project and the state of the soil, may be more than that of conventional foundations. In order to guarantee that the piles are properly positioned and have the capacity to support the necessary loads over time, installation expertise is also essential.

Another thing to think about is the impact on the environment. Although screw piles typically require less space to install than traditional foundations, the sustainability of their manufacture and the materials they are made of should be considered. It’s critical to balance these variables against the project’s unique requirements and environmental factors.

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