Foundation for screw piles

By Admin | Building
30 April 2016

to erect a building must be approached carefully, carefully evaluate all phases of construction.First and foremost, you must determine the type of foundation.But what if your site you are faced with so-called "complex" grounds, which include:

  • Peatlands;
  • Wetlands;
  • Areas with groundwater;
  • Land subject to the forces of frost heaving;
  • Flooded areas.

In this case, one of the fastest and most reliable way to solve the problem is to use a screw-pile foundation.

can highlight the main advantages of the screw pile-foundation:

  • Installation is made within one to two days;
  • not require alignment of the relief portion;
  • No large-scale earthworks;
  • Screwing piles conducted in all weather conditions.

The main disadvantage of a screw-pile foundation are:

  • impossibility of installation on a rocky terrain and in areas with hard limestone layers or rocky soil;
  • piles can not be installed closer than 0.5 meters to an already built home, and in this case the installation is hindered because of the use
    of special instruments;
  • Also note that if you select a screw-pile foundation is significantly complicated by the construction of a house with a basement.And the price of such a foundation becomes unnecessarily high.

Based on the experience of participants we'll tell you:

  • of the construction of a screw-pile foundation;
  • The fact that you need to know to calculate the required number of piles;
  • about the secrets of the screw-mounting pile foundation;
  • On basic errors when screwing piles.

design features screw-pile foundation

foundation on screw piles - a group of piles screwed into the ground and is a single box.With the construction of the houses are mostly used piles with a trunk diameter 108mm, length of 2.5 meters and a diameter of 300mm blade.After the pile is screwed into the ground, it remains on the surface of about 50 cm from its trunk.Then, on the trunk of the pile is welded headroom.The standard version has dimensions 250h250mm headroom.

headroom necessary for mounting on a strapping timber, channel, or raft foundation on which the structure is then mounted.

Pile - a metal tube with a pointed end and a blade attached to the special configuration of its lower part.Thanks to the blade pile screwed into soil, compacting it until it reaches the desired depth, and you are rested in a reliable basis.Because of this pile can carry the design load immediately after installation.

piles vary in length, diameter, and its purpose, namely:

  • Screw pile Ø76 mm - used in the construction of fences,
  • gazebos and light extensions;
  • Screw pile Ø89 mm - suitable for building huts,
  • and piers;
  • Screw pile Ø108 mm - versatile option for the construction of frame and log homes;
  • Screw pile of Ø133 mm and above - used for construction of houses made of logs, concrete blocks and industrial facilities.

When selecting the pile should first pay attention to the following characteristics:

  • thickness of the metal wall of the barrel.In qualitative pile thickness ranges from 4 to 4.5 mm;
  • thickness of the metal blade.It should not be less than 5 mm;
  • weld quality.Unacceptable sinks and undercooked areas;
  • Sheeting piles.If the layer of paint thin or poor quality, it simply erases on the ground at a twisting piles.

It should also be noted that there are piles with a molded tip.The peculiarity of these piles is that the tip of the pile and the blade forms a single piece made in a foundry, which is then welded to the pile shaft.

This pile is considered to be more reliable than conventional welded, as it has a thicker blade and has only one weld.And also can be screwed into the ground, which has the roots of trees or across small stones.

How to calculate the required number of piles?

can often hear the claim that the pile must be screwed into the ground with a certain step.And why calculate the required number of piles is quite simple - we just have to know the length, width and weight of the structure.But as practice shows - it is fundamentally wrong!So how do you know how much driving is necessary for your foundation?

According to its users f , for the correct calculation of the pile field is first necessary to examine the bearing capacity of the soil under the blade of the pile.To this end, on the site, a few control points made trial screwing piles.And on the basis of the data, calculates the required length of the piles and their number for a particular project house.

To calculate the pile foundation, you can use a table which can be used to determine the carrying capacity of screw piles, depending on ground.

minimum depth of screwing piles for Moscow and the Moscow region is 1.5 meters, which guarantees the installation of pile foundation below the freezing depth of soil.Correctly set screw pile Ø108 mm is capable of carrying a load of 5 tons.

Features mounting screw-pile foundation

Screwing screw piles can be made both by mechanical means - with the help of machines equipped with hydraulic drills and manual method - forces of several people.

It should be noted that the mechanical mounting of the pile is easier to control the force required screwing.Also, this method allows you to more accurately center the pile shaft.This achieves a high precision mounting.The maximum deviation of the barrel screwed piles from the vertical axis should not exceed 2 degrees.

Once the pile is screwed to the desired depth, it is done cutting the top.To edge of piles was put on the same level, you must use a laser level.

then poured into the barrel of the pile concrete solution.Contrary to popular belief - this is not done to enhance the pile, and to expel oxygen from the pile and thus prevent corrosion of the metal inside the trunk.In addition, if you are not open to concrete pile, then with the arrival of winter, it can be filled with water and it will break.

What else should pay attention when installing the piles?

  • determine that the pile is screwed all the way, or as they say assemblers, "given the refusal" is possible by the strong deformation of the metal lugs of the barrel;
  • Members forumhouse.rurekomenduyut by pouring concrete into the barrel of the pile Nedolya about 20 cm from the top level of the pile, and the rest of the fill dry cement-sand mixture.This is done in order to pull out of the trunk of residual moisture;
  • After welding end walls, horizontal piping made of piles with each other.Most often used for this purpose beams or metal profiles.If the piles above the surface of the earth for more than 1 meter, for stiffening the entire structure to the pile shaft is made Weld angle additional profiles - struts.

Possible errors when installing screw-pile-foundation:

  • When installing a screw-pile foundation is not allowed exhibiting a uniform level of piles by twisting them.This will ensure that the compacted soil is loosened and the installation and home pile prosyadet exactly the distance that was disintegrating because of its twisting;
  • also one of the most common mistakes is that the pile is screwed into the pre-dug pit.The depth of the so-called "pit" should not exceed 30 cm.

Learn more about pile-helical foundation you can from forum threads, and see our videos you can see how to perform manual installation of pile foundation.