RU2225478C2 - Method of screw-like pile bottom screwing down - Google Patents

Abstract

FIELD: construction of pile foundations for civil and industrial structures. SUBSTANCE: method involves putting pile bottom having cup with square or polyhedral cross section and connected with removable metal tube on soil surface in planned point; fixing removable metal tube at the angle of α to soil surface; passing screwing mechanism formed as power couple of reciprocating hydraulic jacks hung on vehicle through inner gripping sleeve; switching on forward motion regime of one hydraulic jack and reverse motion regime of another hydraulic jack; bringing removable metal tube into rotation in clockwise or counter-clockwise direction; imparting rotational motion to screw-like ferroconcrete pile bottom; feeding lubricating clay pulp beneath sharpened pile bottom end for friction reduction between pile bottom and soil; inserting pile bottom into removable metal tube up to stop; removing metal tube; putting hose of pulp- feeding device into space between pile and soil up to pile lower mark; supplying sand pulp by hose up to full filling of space between pile and soil and pulp rise to soil surface; removing hose without stopping of pulp supply; stopping sand pulp supply; repeating above processes with new pile. EFFECT: increased labor productivity by mechanical aid applying; increased bearing strength. 6 dwg

Description

The present invention relates to the construction of pile foundations for civil and industrial buildings.

A known method of screwing described in the book [1, p. thirteen].

We will take for an analogue a patent [2, No. 2076173]. The analogue describes a method of screwing screw piles. Use the base machine [3, p. 153, Fig. IV.5.6.] With a turntable and hydraulic supports and a guide mast connected to the turntable, with the possibility of installing the guide mast on the ground at different angles to the surface of the earth.

A carriage with a reversible drive is installed on the guide mast, moving along the guide mast, a tubular rod associated with the drive. A tip having a helical protrusion is attached at the end of the tubular rod.

The drive is made of two reciprocating hydraulic cylinders, covering the guide mast with a fork and connected by a housing to the drive housing.

A hollow screw tip having a central square or multifaceted cross-section is installed at the design point on the soil surface, the removable tubular rod of the same cross-section is inserted into the glass until it stops in the bottom of the lost shoe covering the lower hole, and the vehicle’s hydraulic supports are pressed against the soil surface.

The tubular rod is fixed at an angle relative to the soil surface, it is passed through the internal coupling of the ratchet mechanism of the screwing mechanism, the forward stroke of one and the reverse stroke of the other power hydraulic jacks forming a pair are turned on.

The ratchet device converts the reciprocating movements of the external coupling of the ratchet device of the screwing mechanism into the circular motion of the internal coupling of the ratchet device.

Forcibly rotate the retrievable tubular rod clockwise and through it screw the pile tip into the ground to the design mark. The retrievable tubular bar is lowered the reinforcing cage of the pile to the bottom of the shoe and the hose for feeding concrete into the formed helical borehole.

Unscrew the screw tip by rotating the tubular rod counterclockwise, and at the same time concrete and compact the concrete in the screw well. Then the cycles are repeated with the next pile.

In the analogue, for screwing up piles, a power pair of hydraulic jacks of reciprocating action, hinged to the guide mast of the vehicle, was used. The reciprocating effects of hydraulic jacks are converted by a ratchet device [3, p.271, Fig.5.2.23] into rotation.

The device for screwing piles is replaceable equipment, for example, to a crane, excavator, moves along the guide mast and is intended for the manufacture of screw-shaped monolithic piles.

The advantage of the power pair of hydraulic jacks of this device are significant torques that overcome the resistance of the soil base to screwing in a half-screw tip. We take the known device for an analog.

The disadvantage of the analogue:

- placement of the device for screwing piles on the guide mast high above the surface of the soil;

- the absence of a thickened heel in the pile, which reduces its bearing capacity up to ten times and increases the consumption of materials;

- the impossibility of screwing finished reinforced concrete piles and the bulkiness of the equipment.

The technical result of the invention is to increase labor productivity by mechanizing the process of screwing screw heels of piles and increasing the bearing capacity of piles.

The technical result is achieved by the fact that when screwing the screw heels of piles, a screw heel is installed at the design point on the soil surface, having a central square or multifaceted cross-section glass on top.

к поверхности земли и пропускают сквозь внутреннюю муфту захвата механизма завинчивания, выполненного в виде силовой пары гидравлических домкратов возвратно-поступательного действия, подвешенных к транспортному средству.The helix is connected to a steel retrievable pipe, which is fixed at an angle

to the surface of the earth and pass through the internal coupling sleeve of the screwing mechanism, made in the form of a power pair of hydraulic jacks of reciprocating action, suspended from the vehicle.

They include the forward stroke of one and the return stroke of the other hydraulic jacks, which inform the external clutch of the gripper the rotational circular motions transmitted by it through the ratchet mechanism to the internal clutch.

Forcibly rotate the steel pipe to be removed clockwise or counterclockwise and report the unilateral circular motion of the heel of the pile, screw it into the ground to the design mark.

A steel pipe is removed from the ground and operations with the next pile are repeated.

The method is implemented in that the helical heel is reinforced concrete, at the same time as the screwing process, clay clay is pumped under the tip of the reinforced concrete helical heel, which functions as a lubricant. Clay pulp reduces the friction of a reinforced concrete helical heel on the ground.

Before removing the steel pipe, the pile is inserted into it completely into the screw heel, and after removing the steel pipe, the pulp pipe hose is lowered into the gap between the pile and the ground to the bottom mark of the pile. The sand pulp is fed through the hose until the gap between the pile and the soil is completely filled and the sand pulp exits to the soil surface, thereby increasing the bearing capacity of the pile.

The hose is removed without turning off the pulp supply, then the sand pulp supply is turned off, the cycles are repeated with the next pile.

A comparison of the developed method shows its significant differences from the analogue:

- a power pair of hydraulic jacks is suspended at the bottom of the guide mast of the vehicle, resting on a reinforced concrete screw heel;

- the screwing of reinforced concrete screw heels of piles is carried out by means of a removable steel pipe, thereby preventing damage to the reinforced concrete piles;

- reinforced concrete helix increases the area of the pile support by 6 ... 10 times and, accordingly, by 6 ... 10 times increases the bearing capacity of the reinforced concrete pile;

- the resistance of the soil base to the screwing of reinforced concrete screw heels is reduced by forcing clay pulp under the tip of the reinforced concrete screw heel; clay pulp functions as an effective lubricant and significantly reduces the friction of a reinforced concrete helical heel on the ground;

- reinforced concrete piles and helical heels are easily removed and reused;

- the productivity of the process increases.

In FIG. 1, 2 shows the implementation of the method of screwing screw heel piles in two projections; figure 3 is a section along aa in figure 1; in FIG. 4, 5 - reinforced concrete helical heel with a single-entry blade in two projections; in FIG. 6 - with double-entry blades.

The device contains a square or multifaceted, i.e. a non-circular steel pipe 1, along which the internal grip clutch 2 slides with an opening corresponding to the cross-section of the steel pipe 1. The inner clutch 2 is connected to the external clutch 3 by a ratchet mechanism (not shown) [3, p.271, Fig. 5.2.23].

The external clutch 3 transmits the rotation by means of a ratchet mechanism to the internal clutch 2. The reverse direction of rotation is provided by the ratchet mechanism.

The external coupling 3 is equipped with two arms 4 designed for swiveling with a power pair of hydraulic jacks 5. The second end of each of the hydraulic jacks 5 is pivotally connected to their housing 6. The housing 6 of the power pair of hydraulic jacks 5 is suspended below the guide mast of the vehicle 7. Vehicle 7 interacts with the surface of the earth with hydraulic supports 8.

Reinforced concrete heel 9 is manufactured in the factory and has multi-blades 10.

In FIG. Figure 4-5 shows a reinforced concrete helical heel with a single-entry blade in two projections. In FIG. 6 - with double-entry blades. The rod 11 of the reinforced concrete helical heel 9 has a pointed end 12.

In the upper end of the rod 11 there is a central square or multifaceted cross-section glass 13. Each of the blades 10 has at least one turn. Reinforced concrete helical heel 9 is reinforced and made of concrete grade not lower than M400 and should be checked for punching.

Reinforcement of the reinforced concrete helical heel 9 is produced by spiral reinforcement, inclined to the radial direction at an angle of 30 ... 45 ⁰ . The fittings are oriented in the direction of the main tensile stresses when tightening.

In reinforced concrete helix 9 there is, for example, a square cross-section glass 13 with a depth equal to (1.5 ... 2) Δ, where Δ is the size of the side face of the glass 13 in reinforced concrete helix. The lower end of the pile rests against the bottom of the glass in the reinforced concrete heel 9. The depth of the glass 13 should be at least (1.5 ... 2) Δ.

The height h of the reinforced concrete helical heel is equal to h = (3 ... 4) Δ. The size d of the rod of the reinforced concrete helical heel is (1.5 ... 2) Δ, and the largest diameter D is (1.5 ... 2) d, i.e. D = (2.25 .. .4) Δ.

The method of screwing screw heels 9 is as follows:

- at the design point on the soil surface, a reinforced concrete screw heel 9 of the pile 14 with a square or polyhedral cross-sectional glass 13 in the center is installed;

- below to the guide mast of the vehicle 7 is suspended a power pair of hydraulic jacks 5;

- the vehicle 7 drives up to the reinforced concrete helix 9, and the power pair of hydraulic jacks 5 is placed over the reinforced concrete helix;

- combine the glass 13 in the upper end of the reinforced concrete helical heel with the hole in the inner sleeve 2 of the capture;

- insert, into the combined holes, a steel pipe 1 of the same cross section, pass it through the grip and then insert it all the way into the glass 13 in the reinforced concrete heel 9;

- fix the upper end of the extracted steel pipe 1 at a given angle b to the surface of the earth, the boom of the vehicle;

- abut the hydraulic supports 8 of the vehicle 7 in the soil surface and connect the power pair of hydraulic jacks 5 with the external coupling 3;

- at the same time, they turn on the injection of clay pulp under the tip of the reinforced concrete helical heel 9, reducing its friction against the ground, and forcibly screw it with hydraulic jacks 5 by means of an extractable steel pipe 1;

- reduce the resistance to screwing a reinforced concrete helical heel 9 into the soil, pumping clay pulp, which performs the function of effective lubrication;

- at the same time, the laser beam controls the achievement of the projected steel pipe 1 mark;

- insert a reinforced concrete pile into a steel pipe 1 until it stops in a reinforced concrete screw heel 9;

- after removing the steel pipe 1, the pulp line hose is lowered into the gap between the reinforced concrete pile and the soil to the bottom mark of the pile and sand, gravel, slag pulp is pumped through the hose, completely filling the gap between the pile and soil until the pulp reaches the soil surface;

- the hose is removed without shutting off the pulp;

- the supply of sand pulp is turned off, and the cycles are repeated with the next pile.

The economic effect was achieved due to the following:

- increase the area of bearing of reinforced concrete piles on the ground by 6 ... 10 times and a corresponding increase in its bearing capacity and reduce material consumption;

- increase the productivity of the process of building a pile foundation and reduce energy intensity, because the resistance to screwing a reinforced concrete helical heel 9 into the soil is reduced by injection of clay pulp, which performs the function of an effective lubricant;

- repair damage to reinforced concrete piles when screwing;

- reuse of piles and reinforced concrete screw heels 9.

Literature

1. SNiP 2.02.03-85. Pile foundations / Gosstroy of Russia. - M.: GUP TsPP, 1988.-48 p.

2. RF patent No. 2076173 C1, E 02 D 7/22, 03/27/1997.

3. Handbook of cranes: In 2 t., T.2. Characteristics and design schemes of cranes. Crane mechanisms, their parts and components. Technical operation of cranes. M.P. Alexandrov, M.M. Gokhberg, Moscow, Mechanical Engineering, 1988, p. 559.

Claims (1)

A method of screwing screw heels of piles, which includes installing a heel at a design point on the soil surface having a central square or multifaceted cross-section glass connected to a steel pipe to be removed, which is fixed at an angle α to the earth's surface and passed through an internal locking clutch of the screwing mechanism made in the form of a power pair of reciprocating hydraulic jacks suspended from the vehicle, include the forward stroke of one and the reverse stroke of the other hydraulic jacks informing the external coupling sleeve the rotational circular motion transmitted by it through the ratchet mechanism to the internal coupling force the steel pipe to be removed clockwise or counterclockwise and impart a one-sided circular movement of the pile heel, screw it into the ground to the design mark, and remove it from soil steel pipe and repeat the operation with the next pile, characterized in that the screw heel is made of reinforced concrete, simultaneously with the screwing process, clay clay is pumped, performing the function of lubrication, under the tip of the reinforced concrete helical heel, thereby reducing the friction of the reinforced concrete helical heel on the ground, before removing the steel pipe, push it into the screw heel all the way to the stop, and after removing the steel pipe in the gap between the pile and the ground, lower the pulp conduit hose to the lower mark piles, sand pulp is fed through the hose, until the gap between the pile and the soil is completely filled and the pulp reaches the soil surface, increasing the bearing capacity of the pile, the hose is removed without shutting off the pulp supply, then it turns off sand pulp supply, and cycles are repeated with the next pile.

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