RU2620112C1 - Method of arranging pile foundations with widening by method of crushing - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method of arranging pile foundations, in which a hollow pile with a shank of a detachable tip inserted therein is immersed by the method of crushing into the soil to the design mark, its internal cavity is filled with plastic concrete grout. The top pile cap is fixed in the grillage, and then pressure is created in the pile cavity. Prior to the setting of the plastic concrete grout, a piston is inserted into the inner pile cavity, vertical compressive load transferring the pressure to the upper surface of the concrete grout is applied to it, the amount of the vertical compressive load being greater than the force of immersing the pile by the method of crushing.

EFFECT: reducing the cost, material consumption and time of foundation construction, reducing negative impacts on the soil of the foundation and structure of the building.

6 clk, 2 dwg

Description

The invention relates to the field of construction, in particular to methods of building foundations of buildings.

A number of similar methods are known for arranging piles with extensions. For example, in the analogue of the invention [1: G.K. Klein, I.I. Cherkasov. Foundations of urban transport facilities. M .: Transport, 1985. P. 251-252] the internal cavity of the well is filled with plastic concrete mortar, the solution is supplied under pressure to the well, which coincides with the essential features of the proposed.

At the same time, broadening is formed in separate weak soil layers. The cement slurry is supplied under pressure to the well using a concrete pump.

The disadvantage of this method is the need to create high pressure for the formation of broadening, which is difficult to implement using a concrete pump, which leads to an increase in material consumption, cost and time of construction of the foundation.

The closest analogue (prototype) of the proposed method is the method [2: Korolev M.V., Guterman M.S., Skrylev T.E., Sazhin D.V. Effective ways to strengthen foundations in the reconstruction of buildings and structures // Sat-k Proceedings of the Moscow State University of Civil Engineering "Modern methods of engineering surveys in construction." Ed. Telichenko V.I. Moscow, 2003. S. 253-264], in which a hollow pile with a detachable tip shank inserted into it is immersed by pressing into the soil to the design elevation, fill its internal cavity with plastic concrete mortar and create pressure in the pile cavity, which coincides with the essential features proposed.

At the same time, a gradual extraction of the pipe is carried out and the pressure created by the concrete pump forms broadening in places of weak layers of soil.

The disadvantages of this method are similar to the previous analogue.

A positive result of the invention consists in reducing the cost, material consumption and construction time of the foundation, as well as in reducing the negative effects on the soil of the base and structure of the structure.

List of Drawings

FIG. 1a, b, c. The implementation scheme of the proposed method according to p. 1.

FIG. 2a, b. The implementation scheme of the proposed method according to paragraphs. 2, 5.

In FIG. 1 shows the stages of implementation of the proposed method, where the notation is used:

1 - tubular pile; 2 - detachable tip; 3 - tip shank; 4 - concrete mixture; 5 - broadening; 6 - liner piston; 7 - grillage; 8 - coupling and retainer.

The various phases of the structure are shown in FIG. 1a, b, c. The influence of the length of the shank (3) of the detachable tip (2) is shown in FIG. 2a, b.

In FIG. 1a shows the first stage of the method, when a tubular pile (1) with a detachable tip (2) is immersed in the soil with a static load.

In FIG. 1b, the second stage of the method implementation is presented, when after immersion of the pile (1) with a detachable tip (2) to the design mark, the pile head is fixed in the grillage (7) by means of a coupling and a retainer (8) to limit its vertical movements. After that, the cavity of the pile is filled with concrete mixture (4).

In FIG. 1c, the third stage of the method implementation is presented, when a static vertical load is applied to the uncured concrete mix (4) through the insert piston (6), which exceeds the force required to crush the pile. As a result of this, a hydrostatic pressure arises in the concrete mixture, under the action of which the detachable tip of the pile is immersed in the ground, and broadenings are formed under the lower end of the pile (5).

In FIG. Figures 2a and b show the broadening forms (5) for the short and long shank (3) of the detachable tip (2), respectively. With a short length of the shank (3), the broadening thickness (5) will be small with a significant diameter. With a longer length of the shank (3), the broadening form (5) will approach spherical.

In order to overcome these shortcomings, a method of pile foundation construction is proposed, in which a hollow pile (1) with a shank (3) of a detachable tip (2) inserted into it is dipped by crushing into the ground to the design elevation, its internal cavity is filled with plastic concrete mixture (4) , fix the upper pile head in the grillage and then create a pressure in the pile cavity (1), characterized in that a piston (6) is inserted into the internal cavity of the pile (1) before the plastic concrete mix (4) is set, and a vertical piston is applied to it th compressive load, which transfers pressure to the upper surface of the concrete mixture (4), and the magnitude of the vertical compressive load is chosen to be greater than the pile immersion force by the crushing method.

In addition, the length of the shank (3) of the detachable pile tip (1) is chosen taking into account the required geometric dimensions and the shape of the broadening (5) of the lower end of the pile, depending on soil conditions and loads.

In addition, measure the decrease in the level of concrete mixture (4) in the cavity of the pile (1) and the movement of the detachable tip (2), taking into account these measurements, determine the shape and size of the broadening (5) of the lower end of the pile (1).

In addition, the decrease in the level of concrete mixture (4) in the pile cavity (1) and the displacement of the detachable tip (2) are measured, taking into account these measurements, the bearing capacity of the individual pile and the required number of piles are determined to achieve the required total bearing capacity of the foundation.

In addition, the pile is partially filled with concrete mixture, and after the broadening is formed by moving the piston under the action of the load applied to it, the piston is removed, after which the remaining part of the hollow pile is filled with concrete mortar.

In addition, a vibration load is simultaneously applied to the piston, which creates vertical pressure on the surface of the concrete mixture, and to the hollow pile.

The proposed method is as follows.

In a first step of implementing the method, as shown in FIG. 1a, a tubular pile (1) with a detachable tip (2) is immersed in the soil with a static load. Then, as shown in FIG. 1b, after immersion of the pile (1) with a detachable tip (2) to the design mark, the pile heads are fixed in the grillage (7) by means of a coupling and a clamp (8) to limit its vertical movements. After that, the cavity of the pile is filled with concrete mixture (4).

Then, as shown in FIG. 1c, a static vertical load is applied to an uncured concrete mixture (4) through an insert piston (6), exceeding the magnitude of the force required to crush the piles (1). As a result of this, a hydrostatic pressure occurs in the concrete mixture (4), under the influence of which the detachable tip (2) of the pile (1) is immersed in the ground, and under the lower end of the pile (1), broadening (5) is formed.

To reduce the friction of the concrete mixture on the inner walls of the pile, it is partially filled with concrete, then a load is applied to the concrete mixture and, having formed a broadening, the piston is removed and the remaining part of the pile shaft is filled with concrete. It should also be noted that the shape of the broadening significantly depends on the length of the shank of the head, which fits tightly into the cavity of the pile. If the length of the shank is small, then the width of the broadening will be small with a significant diameter, and if the shank will have a longer length, then the shape of the broadening will approach the spherical (see Fig. 2a and b), to give greater mobility of the concrete mixture to the piston forming the broadening additionally apply a vibration load.

The positive effect of the invention is as follows:

- in reducing the cost, material consumption and timing of work (by creating broadening under the lower end of the pile and using the same equipment for all operations that does not require re-installation);

- the ability to control the deformations of buildings under construction and reconstructed. This possibility can be realized by the fact that in the zone of the greatest settlement sediments, the vertical load on the plastic concrete mix can be set more, and in the zone of least deformation - less. As a result of this, the broadening dimensions under the loaded part will be larger than under the less loaded part. Under structures that do not experience deformation, broadening may not be created;

- in the absence of harmful effects during work (noise, significant vibration, dynamic loads);

- the ability to conduct parallel construction and installation works on the installation of foundations and upper structures. For example, first, several floors of the building are built on the grillage, which plays the role of a shallow foundation in the first stage, then, after the construction of part of the floors of the building, the piles are immersed, and then, after the construction of another part of the floors, the piles are concreted with the formation of broadening;

- the fact that the foundation produced by this technology will be practically “non-stop”, since the broadening is carried out with a load exceeding the actual load on the pile from the structure.

As follows from the above analysis, the required technical result is achieved due to significant differences of the proposed method from existing ones.

The experiments showed the feasibility of the proposed object of the invention.

Claims (6)

1. A method of arranging pile foundations, in which a hollow pile with a detachable tip shank inserted into it is immersed by pressing it into the ground to the design mark, fill its internal cavity with plastic concrete mortar, fix the upper pile head in the grill and then create a pressure in the pile cavity that differs the fact that before the plastic concrete mortar is set, a piston is inserted into the internal cavity of the pile, a vertical compressive load is applied to it, which transfers pressure to the upper surface the concreteness of the concrete, moreover, the magnitude of the vertical compressive load is chosen to be greater than the force of immersion of the pile by the crushing method. 2. The method according to p. 1, characterized in that the length of the shank of the detachable tip of the pile is selected depending on the required geometric dimensions and the shape of the lower end, which depend on soil conditions and loads. 3. The method according to p. 1, characterized in that they measure the decrease in the level of concrete mixture in the cavity of the pile and the movement of the detachable tip, taking into account these measurements, determine the shape and size of the broadening of the lower end of the pile. 4. The method according to p. 1, characterized in that they measure the decrease in the level of concrete mixture in the cavity of the pile and the movement of the detachable tip, taking into account these measurements, determine the load capacity of the individual piles and their required amount to achieve the required bearing capacity of the foundation. 5. The method according to p. 1, characterized in that at first the pile is partially filled with concrete mortar, and after the broadening is formed by moving the piston down under the action of the load applied to it, the piston is removed, and then the remaining part of the hollow pile is filled with concrete mortar. 6. The method according to p. 1, characterized in that a vibration load is applied simultaneously to the piston creating vertical pressure on the surface of the concrete mixture and to the hollow pile.

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