Channel and screw foundation

Cost of channel with installation

The price of the channel per linear meter includes; delivery, material (channel), installation work (installation, welding). The price is given for tying the pile field with a channel, without installing complex metal structures and load-bearing frames.

Using a channel when installing screw piles I use it to connect a pile field into a common structure with a uniformly distributed load on each pile.

The channel is used in the construction of foundations capable of bearing a large load of structures erected on them. Usually used channel from 12 to 20. (that is, the distance between the “shelves” is from 12 cm to 20 cm), with piles with a diameter of 108 and a diameter of 133.

Channel 12

Used for screw piles 76 - 89 in diameter.

Channel 14

Used for screw piles 89 - 108 in diameter.

Channel 16

Used for screw piles of 108 diameter.

Channel 18

Channel 20

Used for screw piles of 108 diameter and 133 diameter.

Channels and screw piles of large diameters are used for the installation of foundations designed to carry the load of massive structures: metal structures, stone buildings.

Using a channel in pile-screw structures used in the construction of buildings with a large load-bearing load. Typically, screw piles twisted to the required depth are tied with a channel of the required size (width or distance between the side faces, shelves). As a rule, when installing a channel on screw piles, caps are not used, but there are solutions with mixed use of caps and channel. In these cases, the channel is placed either on its edge, supported and rigidly attached by welding to the ends, or with its flanges up, which in turn allows the beam to be “envyed” and strengthened inside the channel.

When installing a structure from I-beam on screw piles, it makes more sense to mount everything on the installed heads. This allows you to accurately install an I-beam foundation without errors. In particular, when raising houses when the foundation settles when placing an I-beam under the lower crown of the raised building, it is better to install the beam on the head.

The use of a channel in a pile-screw foundation

When installing a channel, the piping is done along the outer contour of the foundation or along the outer and inner. It all depends on the project and load calculations. The contour of the foundation can be of various configurations, including repeating the “oblique angles” of the bay windows. What is important to pay attention to when installing a pile foundation using a channel? Of course, on the quality of welds. If the work is not performed properly, the weld may come apart, which will subsequently lead to loss of structural integrity. Upon completion of installation, the channel is primed with a special anti-corrosion coating.

Particular attention must be paid when installing pile foundations on unstable moving soils in coastal areas and swampy soils. In these places binding of screw piles simply necessary. The fact is that in the future, in soils highly saturated with water, movements are possible, which can then lead to deviation of individual piles from the axis, so the use of a channel is simply necessary.

Foundation tying on screw piles in some cases it may be a combined method. That is, in addition to the channel, a corner and a profile pipe are used as connecting elements; in some cases, part of the foundation is made of monolithic concrete elements. In such cases foundation piping, can be considered a full-fledged iron-concrete grillage.

Screw foundation strapping applicable to any building under the necessary conditions.

Technology and materials for tying foundation screw piles

Application of channel This is one of the options used for tying. For light loads, use a profile pipe or angle. It is often considered sufficient to use timber of the required cross-section as grillage beams connecting the pile field.

The channel is installed on top of the pile and is attached to the upper parts of the piles with a weld. If there is a need foreseen by the project, a head is installed on the screw piles, on top of which a channel or I-beam is mounted. The beam is attached to the top screw pile heads bolted connections, which gives the necessary rigidity to the structure. An angle or profile pipe is used as a material for strapping on the sides of screw piles and is secured with a weld.

Install channel for screw piles In several ways, it all depends on the chosen project of the structure being built and the method of installing the crown on the channel.

Incorrect installation of the channel on the screw pile

Considering that the foundation is the basis of the future building, it is very important to carry out the installation correctly, avoiding errors and errors.
When installing a channel on a side face or an I-beam, it is important not only to fasten (weld by electric arc welding) the metal to the top of the screw pile, it should be taken into account that the metal of the beam must completely cover the shaft of the pile. If this is not done, the pile will be susceptible to moisture getting inside. When installing an I-beam and a channel on a side face, it is wiser to mount it on the head, this will give greater rigidity to the structure.

Correct installation of a channel on screw piles
Using channels of different sizes

It is possible to use a combined channel. Using a channel different sizes. But the difference in size should be taken into account.
The use of a channel is necessary for repair work on the foundation, when lifting a house and installing it on screw piles. Using a channel when installing extensions to an existing building, for example a veranda.

Depending on the method of installation of the channel, a beam is attached to it (if the structure being built involves the use of wood).
If under construction

As their popularity grows, installation of screw piles no longer raises any questions. Although many still do not understand why the pile foundation needs to be tied with a channel. This may frighten a person unfamiliar with the installation process and force him to choose a different type of foundation.

Advantages and disadvantages of a pile foundation

It is thanks to its characteristic features that the pile foundation becomes very popular. In some cases, this is the only possible option for the supporting structure. Initially, screw pile foundations were used by the military, but a large number of advantages allowed it to quickly become widespread in civil engineering.

Advantages of a foundation on stilts

The main reason for the use of pile foundations by the military was the high speed of installation. This is one of the most obvious advantages of this building base. In addition to the speed of assembly, there are a number of advantages:

1. Possibility of installation at any time of the year.
2. Low final cost of the foundation.
3. Installation can be carried out on any soil except rocky soil.
4. No need for excavation work even on uneven areas.
5. Long service life of the finished foundation.

A load-bearing structure on screw piles is 2 or more times cheaper than traditional types of foundation. At the same time, a foundation can be completely installed for small buildings, ready to take the load in one day. In addition, such a foundation lasts 50, 70 or more years. The difference in service life depends on the choice of the piles themselves. High-quality certified supports with anti-corrosion coating can last almost twice as long.

But, like any phenomenon, a pile foundation has disadvantages. They are not critical, but you need to know about them before installation begins.

Disadvantages of a pile foundation

In principle, there are only two disadvantages for a pile foundation:

• impossibility of constructing a basement;
• need for strapping.

Although there is a third disadvantage for a pile-screw foundation - the possibility of purchasing low-quality goods. Homemade screw piles with rough weld marks and poor coating will reduce the service life of the foundation by half.

But when purchasing piles from a manufacturer with a good reputation, this drawback can be eliminated.

Not everyone needs basements, especially since their arrangement requires additional financial investments. You will also need to spend a little money on installing the harness. But even taking into account these expenses, the pile-screw foundation is very economical.

The need for tying piles

The need for strapping for a pile foundation is due to its ability to evenly redistribute the load on the supports. Also, the strapping (grillage) allows you to eliminate the deviation of the pile from the vertical, especially on loose or water-saturated soils. It connects all the piles together and gives rigidity to the structure. Depending on the material of construction of the house and its weight, a certain type of grillage may be required.

Types of pile foundation piping

The methods of connecting piles to each other can be different, but a grillage involves connecting all the piles into a single whole. Although it is additionally possible to create strengthening pairwise connections in the right places. The materials for making the grillage are different:

1. Tree.
2. Metal.
3. Concrete.

Concrete piping is rarely installed due to the labor-intensive nature of this process and, in most cases, unnecessary. The most common types of grillage are the timber or channel type.

Moreover, the piping with channel bars, I-beams and square pipes is slowly displacing the grillage from timber and boards. This is due to the significantly longer service life of metal compared to wood.

How to tie piles

Despite the apparent ease of implementation, tying a pile foundation with a channel or angle requires certain skills. Firstly, you need to be able to use a welding machine at a fairly good level. Secondly, you need to know the nuances of welding the channel to the supports. In addition, the material itself is quite heavy, so you can’t do it without helpers. In general, the sequence of actions is simple:

• level the piles;
• prepare a channel of the required size;
• connect the channel to the piles using welding and bolts;
• apply anti-corrosion coating.

When welding a channel with supports, you need to remember that excessive impact on the metal worsens its characteristics. Therefore, poor use of a welding machine can lead to the appearance of weak points at the points where the grillage is attached to the supports due to metal burnout.

Also, special attention should be paid to the connections of the channel with the corner supports. For quality installation, corner supports are of paramount importance.

If you have doubts about your welding skills and ability to correctly connect the channel at the corners of your future home, it is better to entrust the installation of the strapping to experienced workers. Incorrectly installed piping cannot provide optimal base rigidity. Therefore, when constructing residential buildings, it is better to contact specialists to avoid further problems with the foundation. Moreover, pile manufacturers offer not only their sale, but also installation, including with strapping.

High foundation grillage made of screw piles

A high grillage is a distribution beam that unites the pile heads and redistributes the load on them from the structures above, while its base is located above the ground surface. The main rule in its construction is that the larger the span between the piles, the larger the section of the beam that needs to be used.

This type includes: timber, logs, long-rolled beams (channel, I-beam, angle).

Tying a pile-screw foundation with timber or logs

Strapping beam (Fig. 1) - the most type used in the construction of wooden frame buildings. The section of timber used is: 150x150 mm with a maximum step between piles of 2500-2700 mm, 200x200 mm with a step of 3000 mm. Attached to the head with a pin.

Metal, unlike concrete, does not absorb moisture (although sometimes condensation can form on it), so the issue of arranging waterproofing for a pile-screw foundation is not of such fundamental importance. However, it is still recommended to install a waterproofing liner between the supporting platform (head) and the wooden structure.

Log (see Fig. 2). The first crown of a log structure can be laid directly on the head. The main advantage of the log is the preservation of the integrity of the wood, which increases the resistance of the material to deflection. A rounded log gives greater deflection compared to a solid one. This is due to a violation of the integrity of the hard layers of wood.

In the case of concrete foundation structures, to increase the service life of the frame, it is advisable to make the first crown of the structure from oak or larch. When constructing a foundation made of screw piles, these measures can be abandoned, but only if the grillage height is maintained at least 500 millimeters from the ground level.

Tying a pile foundation with a beam or log is the most economical and at the same time quickly implemented type of connection. It requires that the piles be at the same level to avoid deformation of the frame. If the levels do not correspond to each other, then leveling is performed by partially cutting out the timber (log).

Joining the timber (log) is the next step in the strapping device (Fig. 3). To connect, cuts are made in proportion to each of the bars at the top and bottom, and the bar (log) is folded at a right angle. The joints must be treated with special solutions that protect against moisture and lined with jute.

As for the use of antiseptics for treating timber or logs when installing a grillage, this procedure is mandatory only for concrete foundations. In the case of tying a pile-screw foundation, it is of a recommendatory nature, of course, also subject to the height of the grillage being at least 500 mm from the ground level.

Tying a pile-screw foundation with a channel or I-beam

The design solution of the metal grillage is determined depending on the loads on the foundation SNiP II-23-81* “Steel Structures”, SP 53-102-2004 “General Rules for the Design of Steel Structures”.

Tying with a metal channel or I-beam can be done either using construction equipment or manually (depending on the standard size of the channel or I-beam).

Channel (see Fig. 4 – 7). Depending on the design, it can be laid flat or on an edge. The rib option works better for deflection, but a torsional moment arises, so a paired channel is recommended.

A channel laid flat (flanges down), with a pile pitch of more than 2000 mm, already deflects under its own weight (according to calculations), so using this technology it is advisable to design a distance between piles of no more than 2000 mm.

I-beam (see Fig. 8). This type of grillage is advisable to use when reconstructing the foundation.

In both cases, all elements are connected to each other by welding.

Since long products (channels, I-beams) have sufficient thickness (5 or more millimeters), and the operating conditions of a high grillage imply exposure only to atmospheric corrosion, such structures, even in the absence of additional anti-corrosion protection, will be used for the entire period provided for by regulatory documents (GOST 27751-2014 “Interstate standard. Reliability of building structures and foundations. Basic provisions”). Despite this, after the structure is welded, it (at least for aesthetic reasons) should be treated with an anti-corrosion compound.

Low foundation grillage made of screw piles

A low grillage (shallow foundation or reinforced concrete tape (Fig. 9) is a distribution beam that unites the pile heads and redistributes the load from the structures above them, and its base is located on the ground surface or below. Unlike a suspended one, it distributes the load not only along the heads, but also on the ground (base) underneath.

When using this type of grillage, it is necessary to comply with the requirements that are relevant for concrete foundations, for example, regarding the installation of waterproofing and the use of antiseptics (in the case of the construction of a frame-panel or wooden structure), and also take care to comply with the rules for arranging the base (more details in the section “Finishing the base ").

The height of the reinforced concrete grillage is determined by calculation in accordance with SNiP 52-01-2003 “Concrete and reinforced concrete structures. Basic provisions". Reinforcement is made with flat meshes, usually from A-III (A400) reinforcement. For the grillage, concrete with strength grade B15 or B20 is used. When calculating, just as when calculating a pile field, it is necessary to take into account the uneven distribution of loads along the foundation.

Pile foundations have become widespread due to their undemanding requirements for soil and the relative ease of construction. However, without additional reinforcement, piles may turn out to be too sensitive to displacement loads. Therefore, there is a practice of creating additional piping for such foundations.

Types of strapping.

In construction practice, four types of strapping are most often used:

In turn, any type of fastener can be made in three versions:

• high, i.e. raised above ground level. This option for strapping reinforcement of the base is most common;
• increased when the strapping material lies on the ground;
• recessed, in which the upper plane of the strapping tape coincides with the ground level. It is extremely rare.

This or that type is selected taking into account the height pile foundations and masses of the building.

Necessary materials and tools.

In addition to the actual strapping material (timber, I-beam, channel or concrete), you will need the following:

• circular saw for timber or grinder for metal
• building level
• embedded pins or thick wire rod
• welding machine

In addition, personal protective equipment and work clothing will be required.

Tying technology.

The order and features of the action will depend on the selected type of strapping material. The requirements for the rigidity of the resulting structure remain the same.

Strapping device with a channel or I-beam.

Binding pile foundation channel or I-beam is used in the construction of heavy buildings. In this case, hollow supports must be filled with concrete after installation to increase mechanical strength.

Channel – rolled metal of U-shaped profile. The I-beam has an H-shaped profile. The individual elements are joined by welding. As additional reinforcement of the joint, either bolted connections or rivets are used. If the weight of the structure is small, it is permissible to use metal profiles fastened together with bolts only.

Before starting work, channel or I-beams are cut according to the design markings. Then they are laid out sequentially on supports pile grounds.

IMPORTANT

The mass of rolled metal is quite high. Therefore, it is recommended to use lifting equipment. If this is not available, you should work with the utmost caution.

There are several ways to tie piles with a channel:

• side walls up. With this installation, the channel cavity is additionally filled with concrete to increase strength;
• sides down. This installation is convenient in that the upper plane of the strapping becomes a convenient platform for further construction;
• sideways, when one of the side walls becomes the base of the grillage.

I-beams are laid in such a way that the planes are horizontal.

Method of fastening the harness to the supports pile the base depends on the material of their manufacture:

After welding work, the joints should be cleaned of scale and the metal should be treated with anti-corrosion treatment either with paint or bitumen mastic, which is more reliable. If harness installed in close proximity to the ground, then it makes sense to remove the fertile layer of soil along the perimeter of the building, replacing it with a sand-gravel mixture.

Tying with a wooden beam.

Choosing timber strapping pile foundation may be justified for frame or wooden housing construction. With a relatively small weight, natural wood beams have a sufficient degree of strength to withstand the weight of a residential building. Additional advantages are provided by the low thermal conductivity of wood, which simplifies the solution of home insulation problems.

The problem of rotting and damage by insects can be neglected, since antiseptic drugs successfully solve it. You just need to follow the antiseptic treatment schedule.

The timber can be secured in two ways: with clamps or with threaded fasteners.

Installing the grillage on the clamps.

The use of clamps makes sense when the foundation piles do not have flanges. In this case, a head with a horizontal platform is made for the pile, on which the strapping beam is laid.

Then the beam is covered with a U-shaped metal clamp. Its width should match the width of the beam. The hanging ends of the clamp are attached by welding either to a support pile base, or to the embedded stud in the case of supports made of reinforced concrete.

At the corners of the grillage, the beams are fastened together with metal fastening corners.

Threaded installation.

To implement threaded fasteners, the top of the foundation supports must have a flange (recess). The timber is laid into the flange using through pins or powerful self-tapping screws and secured.

IMPORTANT

To protect the timber from rapid rotting, you should untie the metal and wood. To do this, spacers made of roofing felt or oil-impregnated cardboard are placed between the support and the harness.

The corner connection points of the timber are fixed in any way characteristic of wooden construction (tongue-and-tongue connection, tenon, etc.).

For additional rigidity, the structure is fastened with internal and external metal corners.

It makes sense to tie the foundation with a monolithic concrete grillage only for the construction of a multi-story building made of brick or concrete. While the cost is almost half that of tying with rolled metal, the creation of such a grillage is very labor-intensive and takes time to harden the concrete.

The technology for arranging monolithic piping includes several stages:

• all piles are strictly leveled in height;
• formwork is assembled from boards on top of the supports;
• the formwork box is sealed;
• a reinforced frame made of 10-12 mm wire is laid;
• the piping reinforcement is welded to the base supports (or to metal inserts into it);
• Concrete of a class no worse than M300 is poured.

After a month, the grillage will acquire the required level of strength.

Before starting piping work, you should make sure that all base supports are aligned in height. You can check the presence of a plane along the headbands of the supports either with a laser builder or with a hydraulic level.

The fastening of the wooden beam is located strictly in the center of the beam. If a threaded rod or self-tapping screw enters closer to some edge, then due to uneven load, the material may be destroyed over time.

When purchasing material for strapping, you should pay attention to its quality. For both metal profiles and wooden beams, the quality of workmanship is very important. Uneven surfaces of the grillage can complicate further construction, and in the future lead to cracking of the walls.

The use of ties for pile foundations can significantly improve their characteristics. Due to the simplicity of technological operations, such work can be performed even by low-skilled builders.

Channel tying of the foundation on driven reinforced concrete piles

Tying the foundation with a channel is the final stage of building a pile foundation, and in fact, is the overlap between the structure itself and the foundation. A channel is a metal beam of U-shaped section. A pile foundation is a type of foundation in which the load from a structure to the ground is transmitted through piles of various structures. The piles are connected by a grillage. When constructing such a foundation on driven reinforced concrete piles, excavation work in buildings without basements is almost completely eliminated, or its volume is significantly reduced. In order for the support piles to correspond to clear markings and maintain this position, it is necessary to tie the foundation with a channel or timber. It is worth noting that tying the foundation on driven reinforced concrete piles is mandatory only if the height of the piles above ground level exceeds 60 cm. In other cases, special caps are mounted on top of the piles.

Tying the driven foundation with a channel increases the rigidity of the entire structure. If it is necessary to arrange a large foundation, tying the piles with a channel requires the use of special crane equipment. This solution is quite acceptable for large construction projects with an organized construction site, sufficient free space for the operation of crane equipment and equipped access roads.

Technology of foundation construction on driven reinforced concrete piles with channel tying

The tying of the pile foundation with a channel is carried out immediately after driving the reinforced concrete piles. Acting in some way as a retainer, tying the piles with a channel will prevent violations of the specified foundation parameters under the influence of residual stress in the piles.

Peculiarities of work on channel tying foundations on reinforced concrete piles

• The channel, as a rule, is mounted on piles (heads), which assumes the proportionality of the geometric parameters of the channel and the pile. The piping is carried out along the outer perimeter, and to give additional strength to the structure and ensure its reliability - inside, including the installation of beams connecting two other channels along a perpendicular line and (or) two piles (their heads) diagonally.
• If this is provided for by the project, the channel is installed in such a way as to form a formwork for filling with concrete and creating a reinforcing belt for the subsequent installation of walls.
• As a compromise option, which allows you to preserve the upper “formwork” and the high strength of the grillage, an I-beam of the same size is used instead of a channel.
• The corner joints of channels or beams are connected by butt welding. Particular attention should be paid to fasteners. We do not recommend using only a weld for connection; it is advisable to combine it with bolted connections or rivets.

The sequence of channel tying a pile foundation

1. The level of the upper part of the piles is measured - all ends of the supports must be at the same level. This is done first of all to ensure that the foundation is horizontal. Piles that are located above the required level must either be immersed deeper or cut off. If the supports are located below the required level, then a gasket should be placed on the head.
2. The points of the external corners of the structure on the piles are marked. To do this, the point is defined as the first external corner. Then the remaining corners are outlined in exactly the same way.
3. The accuracy of the angular dimensions of the structure is checked with a square.
4. The first corner of the grillage is made from a channel.
5. The entire channel lining structure of the supports is laid out sequentially from the prepared elements. When all the elements are laid, it is necessary to once again check the straightness of the corners and the horizontality of the entire resulting structure.
6. Fastening channels. It is provided by welding or bolted (rivet) connections. Whatever the requirements for the foundation, a more reliable result is obtained by combining different fastening options. All foundation elements are fixed with a circular type seam. The assembly process involves installing the channel on the pile heads, which ensures high structural strength and the channel has high resistance to lateral loads or side faces down. The inverted channel forms a natural formwork that can be poured with concrete, creating a reinforcing belt for the masonry wall.
7. Anti-corrosion treatment of the structure. Due to the fact that a layer of air forms between the soil and the platform itself, dampness appears, especially in the autumn-winter period, resulting in corrosive damage to the metal surface. To avoid this, after finishing channel tying the supports, the grillage elements are primed with anti-corrosion compounds.

Application of foundations on driven railway piles with channel piping

• Brick houses
• Wooden houses
• Frame country houses
• Garages
• Gazebos
• Outbuildings

The use of a channel for tying the foundation is recommended during construction in lightly loaded structures or when installing a pile foundation in unstable soils. Many resort to channel tying to give the structure an additional margin of safety.

Order a foundation on driven reinforced concrete piles with channel strapping

Tying the foundation with a channel is a guarantee of the reliability and strength of the foundation for any house. The foundation on driven reinforced concrete piles is one of the most versatile and reliable types of foundation actively used in modern construction. The technology of tying the foundation with a channel makes it possible to construct buildings even on unstable and moving soils. Reinforced concrete piles are widely used not only at the stage of creating the foundation itself; if necessary, it is possible to strengthen the foundation with the help of driven piles and tying the foundation with a channel. Our company is ready to provide services for the construction of pile foundations with turnkey channel tying.