RU2763573C1 - Telescopic screw pile with leader pile - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: inventions relate to construction, can be used in industrial and civil construction when erecting pile foundations and foundations in soft soils, in cases where it is necessary to provide support on a load-bearing soil layer located at a considerable depth of occurrence. The telescopic screw pile includes a leader pile with a tapered tip at the end with helical blades and a shell pile inserted into each other with the ability to move along the length of the pile. After submersion, the upper end of the leader pile is rigidly connected to the head mounted on the shell pile, while at its lower end, above the tapered tip with helical blades, an expander is fixed. The expander is made in the form of a sleeve put on a rod. The lower end of the shell-pile has at least one sealing cone and a conductor, which is a guide sleeve for centering both parts of the pile during immersion. Moreover, the cone seal is arranged at the transition from the diameter of the conductor bushing to the diameter of the shell pile shaft, on which the helical blades are fixed.

EFFECT: increasing the bearing capacity of the pile.

12 cl, 13 dwg

Description

The invention relates to construction, can be used in industrial and civil engineering, in the construction of piled foundations and foundations in soft soils, in cases where it is necessary to provide support on a bearing layer of soil located at a considerable depth, while improving the characteristics of the upper weakly bearing soil layers , creating a combined load perception system (“hanging-standing” piles).

There are various technical solutions in the area under consideration.

So, the patent of the Russian Federation for utility model No. 187577 (MPK E02D 5/52, E02D 5/56, published on 12.03.2019) “A telescopic screw pile made of fiberglass pipes with a support cap” is known, consisting of a lower and upper parts, a trunk of the lower part has helical blades, and the smooth trunk of the upper part is placed freely inside the trunk of the lower part; through holes of the same diameter are arranged in the trunks of both parts; the combination of both parts into a rigid structure is made by a pin, which is inserted into the aligned hole in the shafts of both parts of the pile; the head of the upper part of the pile is pivotally connected by a pin to the support head, which can be bolted to the lower chord of the cutting inclined edge of the ice cutter. The location of small sections of the piles made of fiberglass "pipe in pipe" is used only to connect 2 parts of the piles to each other or to the support head, has disadvantages and cannot be compared with the proposed technical solution.

A patent of the Russian Federation for a utility model No. 191858 is known (MPK E01D 19/04, published on 08/26/2019). The telescopic drill-dropping tubular rack with a support head for PARM consists of two tubular shafts in height, the shaft of the lower part has a larger diameter, ends with a support round disk and is located in the well; the upper part of the rack - the insert - is freely placed in the trunk of the lower part; in the trunks of both parts there are through holes of the same diameter for the bearing pin, which in the insert are located with the same pitch along the entire length of the trunk, and in the lower part there are several holes only in the head, while the vertical axes of the holes are located along the circumference of the trunk through equal angles, and horizontal axes are located at equal distances from each other along the length of the barrel head; a support cap is freely installed on the insert head, consisting of a skirt made of a pipe section and a support square sheet welded to it with holes for bolted connection with the crossbar beam; the working position of the base plate of the headgear on the insert is fixed by two clamping bolts arranged on the side surface of the headgear skirt; at the same time, both parts of the rack, the headband and the bearing pin are made of fiberglass.

A patent of the Russian Federation for a utility model No. 191864 is known (MPK E02D 5/52, E01D 19/14, published on 08/26/2019). The head telescopic screw pile made of fiberglass pipes for the cluster inventory icebreaker consists of two parts in height - the lower and the upper parts, the smooth shaft of the lower part has helical blades, and the shaft of the upper part, the inner diameter of which is slightly larger than the outer diameter of the lower part, is freely mounted on the shaft the bottom of the pile; on the outer surface of the shaft of the upper part, vertical corners are rigidly fixed for attaching icebreaker side plating shields to the pile and a cutting corner; in the shafts of both parts of the pile, through holes of the same diameter are arranged to accommodate a bearing pin in them, which is inserted into the matching holes of both parts to combine them into a rigid structure of the pile of the required length.

A patent of the Russian Federation for the invention No. 2597420 (IPC E02D 5/56, published on 09/10/2016) is known. Prefabricated screw pile includes a shaft and at least one blade, and the shaft consists of a group of sequentially stacked elements, containing end elements and intermediate elements provided with a group of docking holes, each intermediate element is made of two stacked on top of each other vertical cylinders of different diameters, and each end element contains a part corresponding to the intermediate element, made in the form of a vertical cylinder, and each cylinder with a smaller diameter is installed inside the corresponding cylinder with a larger diameter by means of fasteners located in the group of docking holes. The prefabricated screw pile screwing device includes a housing, a pile fixing mechanism, a pile screwing mechanism and a group of handles, wherein the pile fixing mechanism, the pile screwing mechanism and the group of handles are connected to the body, while the pile screwing mechanism contains a worm gear. SUBSTANCE: method for screwing a prefabricated screw pile includes screwing a prefabricated screw pile by means of a device for screwing a prefabricated screw pile, wherein the height of the prefabricated screw pile is adjusted by successively placing the required number of elements of the pile shaft on top of each other before screwing the prefabricated screw pile or after partially screwing the prefabricated screw pile.

A patent of the Russian Federation for the invention No. 2685519 (IPC E02D 5/56, published on April 19, 2019) is known. The screw pile includes a cylindrical shaft and a helical blade connected to the lower end of the shaft, contains a hollow cylindrical element, open at the ends, having inner and outer side surfaces, located coaxially to the shaft and connected to it through stiffening ribs connecting the inner surface of the cylindrical element and the outer surface shaft, while the lower end of the cylindrical element is located in the gap between the helical blade and the expected level of immersion of the pile into the ground, and the upper end of the cylindrical element is located in the interval from the expected level of immersion of the pile into the ground to the upper end of the shaft, while the lower ends of the stiffeners are provided with platforms located in a plane perpendicular to the longitudinal axis of the shaft, and are not lower than the expected level of immersion of the pile into the ground.

WO 9914441 (IPC E02D 27/42; E02D 5/56; E02D 5/80, published 03/25/1999). The screw pile contains a tubular shaft with a screw thread and a mechanism for engagement with the ground. The stabilizing node has a plurality of ribs. The mounting plate of the light column assembly can be attached to the ribs via mounting bolts. The stabilizing assembly through the ribs increases the resistance of the shaft to lateral movement, for example under wind loads.

US 2014/0301791 (IPC E02D 5/56, published 10/09/2014). Telescopic foundation screw piles with a continuously tapering pile body for faster piling speeds. It has low cleaning overhead, low cost and ease of use with increased load capacity.

Known methods and devices for screw piles with increasing the length of the pile by placing a section of one pile into another:

Thus, patent GB 2397327 (IPC E02D 5/56, published on July 21, 2004) is known, which is the closest to the proposed technical solution, respectively, taken as a prototype. The placement of a small section of one pile inside the other serves only to join the two parts of the pile by means of bolted connections, turning the pile into an ordinary elongated pile, which is wrapped from the surface, which does not have the effect of reducing the friction resistance during immersion, and, accordingly, achieving the immersion depth and bearing capacity without the use of additional operations, compared with the proposed technical solution. In essence, a pile built up by this method has the same disadvantages as a standard screw pile of increased length, and in addition it has such a disadvantage as the possibility of “littering” the pile cavities with soil through an unprotected gap in the upper part of the joint of the pile parts.

Thus, the technical problem in the area under consideration lies in the low bearing capacity of known piles without additional technological operations. The objective of the proposed technical solution, aimed at solving the technical problem, is to create an integrated system of load perception in weakly bearing and non-bearing soil layers, in order to increase the bearing capacity of the pile, due to:

- increase in the density of weakly bearing soils and friction along the side surface of the pile body;

- transferring the load to the ball of incompressible soil in several compaction zones formed from the indentation of the sealing cones;

- soil resistance to vertical loads in the bearing surface of the blades (propeller, auger);

- increasing the diameter of the upper part of the pile and the possibility of pinching the pile in the body of the foundation when organizing a two-level head to ensure its stability from horizontal loads.

When the proposed design of the pile is immersed, in the region of the tip of the leader pile and the sealing cones of the shell pile, zones of load perception are formed from the pressure-compacted cone of the pile of soil, and the helical track (trace from the passage of the blade (spiral)) is closed and the soil is compressed along the side surfaces due to increasing the pile diameter.

The technical result of the proposed technical solution is to increase the bearing capacity of the pile without additional technological operations.

The technical result is achieved by the fact that in a telescopic type screw pile, including a leader pile with a conical tip at the end with helical blades and a shell pile inserted into each other with the possibility of moving along the length of the pile, according to the invention, the upper end of the leader pile after immersion is rigidly connected to head installed on the shell pile, while at its lower end, above the conical tip with helical blades, an expander is fixed, made in the form of a sleeve put on the leader pile, and the lower end of the shell pile has at least one sealing cone and a conductor representing of a guide sleeve for centering both parts of the pile when immersed. Moreover, the cone seal is arranged at the point of transition from the diameter of the bushing of the conductor to the diameter of the shell pile shaft, on which at least one helical blade is fixed.

Additional features of the invention:

- the leader pile is made of metal;

- pile shell is made of metal

- pile shell is made of polymeric material;

- pile shell contains in its upper part the second sealing cone;

- pile shell contains in its upper part the second helical blade;

- helical blades are made with a pitch of 1.5-2 turns or in the form of a multi-turn spiral;

- the head is made in two tiers;

- the conductor is connected by welding by means of radial plates with a metal sheath pile;

- the conductor is glued together with a pile sheath made of polymeric material;

- the tip is made cast or welded with helical or spiral blades.

The technical result is also achieved due to the fact that in the method of constructing a telescopic screw pile, which includes immersing the pile without extracting the soil by screwing the pile into the soil manually or mechanically, according to the invention, the leader pile is first screwed to the maximum depth, then the pile shell is put on it. and plunges to the design mark or failure, compacting the weak upper layers of the soil, the leader pile remains in the body of the shell pile, after filling the cavities of the leader pile and the shell pile with concrete or cement-sand mixture, both piles are connected at the head, allowing for a rigid connection of the pile with the foundation . The supporting part of the leader pile, which has reached the bearing layer with minimal effort to overcome the reactive resistance of the soil during immersion due to the reduced diameter of the leader pile shaft, remains in the soil.

The essence of the invention is illustrated by the following graphics presented in the figures:

fig. 1, which shows a diagram of the perception of loads by a screw pile when organizing leader immersion of the leader pile, where: 1 - leader pile (with a blade or a spiral); 2 pile shell of complex load perception (single-bladed, with two sealing cones; 3 head; 4 zone of load perception by compacted soil from the pressure of the sealing cone in the tip of the central rod and resistance to settlement by the blade (screw) in the bearing soil layer; 5 zone of load perception by compacted soil from pressure of the first sealing cone of the shell pile of complex load bearing; 6 - zone of load perception by compacted soil of resistance to subsidence of the blade (screw) of the shell pile of complex load bearing; 7 zone of load bearing by the compacted soil from the pressure of the second sealing cone of the shell pile of complex load bearing; 8 - zone of perception loads with compacted soil from friction of the side surfaces of the pile; 9 - non-bearing bulk soil; 10 weakly bearing soil; 11 bearing soil support layer; 12 cone compactor; 13 tip; 14 blades; 15 conductor;

fig. 2, which shows a telescopic pile with a leader pile, 2-blade, single-cone, where 16 is an expander;

fig. 3, which shows a telescopic pile with a leader pile, 2-blade, 2-cone;

fig. 4, which shows a telescopic pile with a leader pile, 3-blade, 2-cone;

fig. 5, which shows the device of the expander on a screw bladed pile;

fig. 6, which shows a telescopic pile with a leader pile, 2-helix, single-cone;

fig. 7, which shows a telescopic pile with a leader pile, 2-helix, 2-cone;

fig. 8, which shows a telescopic pile with a leader pile, 3-spiral, 2-cone;

fig. 9, which shows the section a-a to figures 2-4, 6-8, which shows the radial plates, through which the conductor is connected by welding to the pile shaft of the shell made of metal, where D is the diameter of the central rod, D ₁ is the diameter shell piles, D _k conductor diameter; 17- radial plates;

fig. 10, which shows a diagram of a single-tier head, where 18 is fine concrete, DSP;

fig. 11, which shows a diagram of a two-tier head for a monolithic slab, where 19 is a base plate, 20 is an anchor block;

fig. 12, which shows a two-tier head for tying from rolled metal, where 21 are stiffeners;

Fig.13, which shows a view of the pile shell of a polymeric material.

In a telescopic screw pile, including a leader pile 1 with a conical tip at the end and helical blades and a shell pile inserted into each other with the ability to move along the length of the pile, the upper end of the leader pile 1 after immersion is rigidly connected to the cap 3 installed on the shell pile 2, while at its lower end, above the conical tip with helical blades, an expander 16 is fixed, made in the form of a sleeve, put on the rod 1. sealant. Pile shell 2 contains in its upper part a second sealing cone and a second screw-type cutting element. Moreover, on the body of the steel pile of the shell (seal), the number of sealing belts and blades and their binding in depth is set in the project, depending on engineering and geological conditions.

The cutting elements are made in the form of helical blades or in the form of a multi-turn spiral. Head 3 is made of two tiers. The cone seal is arranged at the transition point from the diameter of the bushing of the conductor to the diameter of the shaft of the shell pile 2, on which at least one helical blade is fixed. The helical blades have 1.5-2 propeller pitches. The leader pile 1 is made of a metal pipe. The pile shell 2 is made of a metal or polymer pipe. The tip is made cast or welded with helical or spiral blades. The conductor is connected by welding by means of radial plates with a pile shell.

In the method of constructing a telescopic screw pile, which includes immersing the pile without extracting the soil by screwing the pile into the ground manually or mechanically, first the leader screw pile 1 of smaller diameter is screwed to the maximum depth, then a pile shell (seal pile) is put on it and plunged to design mark or failure, compacting the weak upper layers of the soil, the leader pile 1 in the supporting part remains in the ground, and the part located in the body of the sealing pile remains as a reinforcement element, allowing for a rigid connection with the foundation using the head 3, the cavity of the leader pile and sealing piles are filled with fine-grained concrete or DSP.

Differences of the proposed technical solution from the previously known:

1. An internal screw pile of a bladed or spiral type has a significantly smaller diameter compared to a shell pile.

2. An expander is installed on the inner pile, which, when the assembly kit is immersed together, acts as a fuse against “littering” of the pile cavity with soil, and when the pile is advanced as a leader, it compacts the soil in contact with the pile body, expanding the well, to facilitate the immersion of the pile - sealant.

3. The screwing of the internal screw pile occurs without the use of a reusable rod; achievement of the required level of immersion is carried out by increasing the length of the pile, the shaft of which, due to its small diameter, remains in the body of the sealing pile as a reinforcement element, and is filled with concrete or a cement-sand mixture.

4. The design of the conductor, located at the lower end of the sealing pile, differs significantly from the telescopic pile, and is a single element with the sealing cone of the shell pile.

5. The possibility of installing a 2-tier head, due to the placement of the leader pile in the body of the pile and the increase in the diameter of the pile in the upper zone, makes it possible to ensure that the pile is rigidly pinched in the foundation, foundation slab or piping of the metal frame of the building (structure), which is important for the redistribution of deformations and compensation of loads on the elements of the pile foundation, and is of great importance for ensuring the deformation resistance of the building to the perception of vertical and horizontal loads when constructing foundations on weakly bearing soils.

Thus, thanks to the proposed technical solution, an integrated system of load perception in weakly bearing and non-bearing soil layers is created in order to increase the bearing capacity of the pile.

Claims (12)

1. A telescopic screw pile, including a leader pile with a conical tip at the end with helical blades and a shell pile inserted into each other with the ability to move along the length of the pile, characterized in that the upper end of the leader pile after immersion is rigidly connected to the cap installed on the pile-shell, while at its lower end, above the conical tip with helical blades, an expander is fixed, made in the form of a sleeve, put on the leader pile, and the lower end of the pile-shell has at least one cone seal and a conductor, which is a guide bushing for centering both parts of the pile during immersion, wherein the cone seal is arranged at the transition point from the diameter of the conductor bushing to the diameter of the pile-shell shaft, on which at least one helical blade is fixed. 2. A screw pile according to claim 1, characterized in that the shell pile contains a second sealing cone in its upper part. 3. Screw pile according to claim 1, characterized in that it contains the second helical blades. 4. Screw pile according to claims 1, 2, characterized in that the screw blades have 1.5-2 screw pitches. 5. Screw pile according to claims 1, 2, characterized in that the screw blades are made in the form of a multi-turn spiral. 6. Screw pile according to claim 1, characterized in that the head is made of two tiers. 7. Screw pile according to claim 1, characterized in that the leader pile is made of metal. 8. Screw pile according to claim 1, characterized in that the pile-shell is made of metal. 9. Screw pile according to claim 1, characterized in that the pile-shell is made of a polymeric material. 10. Screw pile according to claim 1, characterized in that the tip is cast or welded with helical or spiral blades. 11. Screw pile according to claim 8, characterized in that the conductor is connected by welding by means of radial plates with a shell pile. 12. The method of constructing a telescopic screw pile according to claim 1, including immersing the pile without extracting the soil by screwing the pile into the ground manually or mechanically, characterized in that the leader pile is first screwed to the maximum depth, then the pile-shell is put on it and immersed to the design mark or failure, compacting the weak upper layers of the soil, the supporting part of the leader pile remains in the soil, while the part located in the body of the sealing pile remains as a reinforcement element in the body of the shell pile, after filling the cavities of the leader pile and pile shells with concrete or a cement-sand mixture, both piles are connected at the head, allowing for a rigid connection of the pile with the foundation.

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