RU2342490C1 - Screw pile and method of its construction - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: screw pile includes a hollow shaft and, at least, one hollow screw blade. Form and volume of the blade may be modified, for example, by flattening and subsequent spreading of, at least, a part of the blade.

EFFECT: easier immersion and increased bearing capacity of screw pile.

6 cl, 1 dwg

Description

The group of inventions relates to the field of construction and can be used in the construction of foundations of buildings and structures.

Known screw pile [Zhelezkov V.N. Screw piles in the energy and other construction sectors. - SPb .: Pragma, 2004. - 20-21 p.], Containing a hollow barrel with a screw blade fixed to the barrel. A method of erecting this screw pile involves dipping the pile by screwing it into the ground and concreting the pile shaft.

The disadvantage of this screw pile is the low bearing capacity of the pile due to the insufficient strength of the blade, having a small cross-sectional area, and insufficient degree of compaction of the soil during its construction.

The closest technical solution to the claimed invention is a screw pile [SU, and.with. No. 1010203, E02D 5/54, E02D 5/56, publ. 04/07/1983. Bull. No. 13], including a hollow barrel with helical blades. One of the blades is fixedly mounted on the barrel, and the other is hollow and mounted on a hub mounted on the barrel with the possibility of movement and rotation relative to it. Immersion of a screw pile in the soil is carried out by screwing. To increase the rigidity of the helical blade, its cavity is filled with cement-sand mortar or fine-grained concrete.

The disadvantage of this screw pile and the method of its construction is that when screwing there is a high friction resistance to the movement of the hollow blade due to the large area of its cross section.

The objective of the invention is to develop a screw pile, providing its easier immersion by screwing by reducing resistance by reducing the cross-sectional area of the hollow blade before the pile is immersed and increasing the bearing capacity of the erected screw pile by increasing the cross-sectional area of the hollow blade after the pile is immersed.

The essence of the claimed invention to the device lies in the fact that the screw pile includes a hollow shaft and at least one hollow screw blade, made with the possibility of changing its shape and / or volume, for example, by flattening and subsequent expansion of at least part the blades.

At least part of the blade can be made of a material with high ductility and low deformation resistance, for example, from a metal sheet, to prevent destruction of the blade during flattening and expansion. The other part of the blade can be made of durable material with high deformation resistance to prevent the destruction of the blade when screwing and improving its cutting ability.

To improve the sealing of the cavity of the blade in it can be placed containers of elastic material having channels for supplying and discharging filling material. This increases the reliability of the expansion of the blade.

The inner surfaces of the blades can be equipped with incandescent elements to create in the process of screwing a steam jacket on the outer surface of the blade and thereby reduce friction on the ground and facilitate screwing the piles.

When a screw pile blade is hollow with the possibility of changing its shape and volume, for example, in the direction of reduction by flattening, the cross-sectional area of the blade decreases, which, when the pile is immersed, reduces the frictional force resistance along the surface of the pile blade and facilitates its screwing. The increase in the volume of the pile blade after immersion by straightening at the optimum speed due to injection of filling material into the cavity of the blade under pressure leads to the necessary compression and compaction of the surrounding soil adjacent to the blade, which increases the bearing capacity of the pile.

There can be several blades on a screw pile to increase the bearing capacity of the pile and increase reliability. The blades can be located not only on the pile shaft, but also on the hub mounted on the shaft with the possibility of movement and rotation relative to it.

The essence of the claimed invention to a method of erecting a screw pile is that in the known method, comprising immersing the pile into the soil by screwing and filling its cavities with the filling material, according to the invention, the pile blade is flattened before screwing. And after the piles are immersed in the soil, the blade is straightened, for example, by filling material under pressure into the cavity of the blade.

When a screw pile is immersed, its surfaces can glow.

After filling the cavity of the pile shaft, solid elements may be immersed in the filling material.

Flattening of the hollow blade of the pile is perpendicular to the outer surfaces of the blade.

The essence of the claimed group of inventions is illustrated by graphic material, where the drawing shows a General view of a screw pile in section.

A screw pile includes a hollow barrel 1, a screw blade 2 with a cavity 3. The blade 2 consists of two parts made of metal sheets. The upper part 4 is made of a material with high ductility and low deformation resistance to facilitate deformation of the blade by flattening. The lower part 5 is made of a material with high strength and high deformation resistance to facilitate screwing. The connection of parts 4, 5 with each other and to the trunk 1 of the pile can be carried out by known methods, for example by welding. The cavity of the blade is equipped with a supply 6 and outlet 7 tubes.

The method of construction of a screw pile is as follows. Before diving, the upper part 4 of the blade 2 is flattened perpendicular to its outer surface to position 8 (shown by a dashed line). As a result of flattening, the blade 2 changes its shape and volume and has a minimum cross-sectional area, thereby it cuts through the soil more easily and therefore the screwing of the pile is facilitated. After the piles are immersed by screwing the blades 2 into the cavity 3 through the tube 6 with a pump (not shown) under pressure, filling material is supplied at a certain speed with the tube 7 closed. At the same time, the upper part 4 of the blades 2 straightens to a given position 9 (shown by a dashed line). The expanded blade 2 of an increased volume allows to obtain a screw pile with increased bearing capacity due to compression and compaction with the optimal speed of the soil adjacent to the blade 2. The hollow pile shaft can also be filled with filling material.

When the pile is immersed, the surface of the blade 2 is heated using electric heaters (not shown) placed in its cavity 3 to create a steam jacket that reduces the friction of the soil and facilitates screwing the pile.

To fill the cavity 3 of the blade 2, liquid (expanding cement mortars, water, mineral oil, etc.) or gaseous materials can be used. To fill the hollow trunk 1 of the pile can be used solid (all types of piles, fittings and other devices) and / or bulk (soil, concrete) materials.

The invention provides the ability to control the thickness of the pile blades, which reduces the energy consumption of the screw pile and the dynamic impact on the environment, as well as increase the bearing capacity of the piles.

Claims (6)

1. A screw pile comprising a hollow shaft and at least one hollow screw blade, characterized in that the blade is made with the possibility of changing its shape and volume, for example, by flattening and subsequent expansion of at least part of the blade. 2. A screw pile according to claim 1, characterized in that at least part of the blade is made of a material with high ductility and low deformation resistance, for example, from a metal sheet. 3. A screw pile according to claim 1, characterized in that in the cavity of the blade there are containers made of elastic material having channels for supplying and discharging filling material. 4. The method of erecting a screw pile according to claim 1, comprising immersing the pile into the soil with screwdriving and filling its cavities with filling material, characterized in that prior to screwing the pile blade is flattened, and after screwing it into the soil it is straightened, for example, by applying a material under pressure filling in. 5. The method according to claim 4, characterized in that when the screw pile is immersed, its surface is heated. 6. The method according to claim 4, characterized in that after filling the cavity of the pile shaft into the filling material, additional solid elements are immersed.