RU2503777C1 - Cross-bladed pile - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: cross-bladed pile comprises a shaft in the form of a steel pipe and two blades, every of which represents a semicircle with diameter that is more than the diameter of the pile shaft. The lower end of the shaft is cut by one half of its diameter at the angle α from the line perpendicular to the axis of the shaft, and to the other half of its diameter at the angle 180°-α from the line perpendicular to the axis of the shaft, and to inclined surfaces produced as a result of cutting in the end of the shaft there are blades welded. Each blade is welded to the appropriate end of the shaft with arrangement of the extreme point of the blade on the line of the semicircle diameter at its one side in the extension of the generating external surface of the shaft, at the same time the specified extreme points of semicircles are arranged at different sides of the shaft and on the common line stretching via the shaft perpendicularly to the axis of the shaft.

EFFECT: increased operating properties of a pile, reduced loads at blades as they cut into soil, increased reliability and durability of blades.

5 dwg

Description

The invention relates to the field of construction, namely, to the designs of screw piles for various types of soils.

Recently, with the construction of foundations for fixing in the soil of buildings and structures, steel screw piles have become widespread. Screw piles, in contrast to smooth piles, have an increased bearing capacity for both indentation and tearing. In smooth piles, the bearing capacity is provided mainly due to friction on the side surface of the pile, and in screw piles due to friction on the side surface and additionally due to the supporting surface of the screw.

However, the manufacture of screw piles, currently used, requires significant costs for their manufacture. So the tips of screw piles are either cast or welded (RU 85919, publ. 08.20.2009; RU 80690, publ. 02.20.2009; RU 110763, publ. 11.27.2011).

The casting technology is quite complicated and expensive and there is an additional problem of ensuring high-quality welding of the cast tip with the pile shaft, because the tip and shaft of the pile are made of different grades of steel due to the fact that they are obtained using various technological processes - casting and rolling.

The production of welded screw piles is also quite difficult, because it requires either special, expensive screw winding machines, or the screw is formed from separate flat plates, which are subsequently welded together into a screw, which is a rather time-consuming process.

In connection with this, designs of the so-called cross-lobed piles appeared, in which blades in the form of flat semicircles are welded to the end of the pipe-trunk (JP 9324425, publ. 16.12.1997; JP 11140871, publ. 05.25.1999; JP 11200363, publ. 27.07. 1999; JP 2001064967, published March 13, 2001). Such piles are more technological and simpler in design and manufacture.

For example, a cross-leg pile is known, containing a trunk in the form of a steel pipe and two blades, each of which is a semicircle with a diameter larger than the diameter of the pile shaft, while the lower end of the trunk is cut into one half of its diameter at an angle a from a line perpendicular to the axis of the shaft, and on the other half of its diameter at an angle of 180 ° -α from the line perpendicular to the axis of the barrel, and blades are welded to the inclined surfaces formed as a result of shearing (JP 2000170159, E02D 5/56, publ. 06/20/2000).

The disadvantage of this pile is that the blades are welded with the exit of their surfaces beyond the surface of the trunk-pipe. This leads to increased loads of cutting the soil when deepening the piles, since such a pile is cut into the ground with a fairly wide knife edge. The presence of such an edge entering the soil leads either to delayed immersion of the pile, or to the need for high loading of the pile with torque. But in the first case, the installation of such a pile requires a lot of time and control over the load on the pile in order to maintain the algorithm of its immersion in a given type of soil. In the second case, breakdowns of piles or torque-generating equipment are possible.

The present invention is aimed at achieving a technical result, which consists in improving the performance of a cross-blade pile by reducing the load on the blades when they are embedded in the ground and reliability and durability by increasing the service life of the blades.

The specified technical result is achieved in that the cross-blade pile contains a trunk in the form of a steel pipe and two blades, each of which is a semicircle with a diameter larger than the diameter of the pile shaft, while the lower end of the trunk is cut into one half of its diameter at an angle α from the line, perpendicular to the axis of the barrel, and to the other half of its diameter at an angle of 180 ° -α from the line perpendicular to the axis of the barrel, and blades are welded to the inclined surfaces formed at the end of the barrel, each blade is welded corresponding to the location of the barrel end at a point on the semi-circle diameter line on one side thereof for forming a continuation of the outer surface of the barrel, said end points semicircles arranged on opposite sides of the barrel and on a common line extending through the barrel perpendicular to the barrel axis.

These features are significant and are interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

The present invention is illustrated by a specific example of execution, which, however, is not the only possible, but clearly demonstrates the possibility of achieving the desired technical result.

Figure 1 is a General view of the cross-blade piles;

figure 2 is the same as in figure 1, side view;

figure 3 is a section along the axis of the cross-piled piles;

figure 4 is a bottom view of the blades;

5 is a blade in plan.

According to the present invention, a new construction of a cross-blade pile is considered (FIG. 1).

The cross-lobed pile consists of a barrel 1 made of a steel pipe of length L and diameter D ₁ , and two blades 2, each of which is a flat semicircle with a radius R, and the diameter of the blade 2R is larger than the diameter of the shaft of the pile D ₁ , with the lower end the pile shaft is cut into one half of its diameter at an angle α (the angle of inclination of the blade from the condition of the formation of a helical angle) from the line perpendicular to the axis of the pile shaft, and into the other half at an angle of 180 ° -α, and then to the inclined surfaces formed as a result of cutting butt st The pile wave is welded onto the blades in such a way that they do not protrude or slightly protrude beyond the edge of the pile shaft from the side of the lower points of the pile trunk, and they protrude as much as possible from the side of the upper points of the pile trunk cut. Each blade is welded to the corresponding end of the trunk with the location of the extreme point on the diameter line of the semicircle on one side on the extension of the outer surface of the trunk, while these extreme points of the semicircles are located on opposite sides of the barrel and on a common line passing through the barrel perpendicular to the axis of the barrel. Thus, the blades 2, speaking in different directions from each other, form the external diameter of the crosstalk piles D ₂ . In this case, two holes are formed in the lower part of the pile between the surfaces of the blades and the pile shaft, through which the soil penetrates into the cavity of the pile when the pile is immersed, which makes it easier to immerse the pile due to the fact that the soil does not compact under the lower end of the pile, like conventional screw piles, which, in turn, allows you to immerse piles in the ground without drilling the leader pit and using equipment with less torque. Depending on the diameter, cross-piled piles, as well as screw piles, can be broad-bladed or narrow-bladed.

A feature of such a pile is that each blade is welded to the corresponding end of the trunk with the location of the extreme point on the diameter line of the semicircle on one side on the extension of the generatrix of the outer surface of the trunk. As a result, in such a pile, the cutting edge of the blade entering the soil is absent. The blade enters the ground with a smooth build-up of the blade from the zero mark (on the generatrix) to the maximum mark (on the opposite end of the blade). This allows the blade to smoothly enter the soil with minimal resistance, and then enter the blade itself. As the input part of the blade wears out, its initial point shifts around the pile, preserving the serviceability of the pile as a whole. This can significantly increase the life of the pile.

The proposed cross-blade pile is distinguished by the fact that with a bearing capacity not worse than screw, the process of its manufacture is much simpler, because It does not require any special equipment and complex technological processes.

Claims (1)

A cross-lobed pile containing a barrel in the form of a steel pipe and two blades, each of which is a semicircle with a diameter larger than the diameter of the pile shaft, while the lower end of the shaft is cut into one half of its diameter at an angle α from a line perpendicular to the axis of the shaft, and the other half of its diameter at an angle of 180 ° -α from the line perpendicular to the axis of the barrel, and blades are welded to the inclined surfaces formed as a result of the cut at the barrel end, characterized in that each blade is welded to the corresponding barrel end ol with the location of the extreme point of the blade on the line of the diameter of the semicircle on one side on the extension of the forming outer surface of the barrel, while these extreme points of the semicircles are located on opposite sides of the barrel and on a common line passing through the barrel perpendicular to the axis of the barrel.

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