RU2244780C1 - Method for building shallow foundation post having camouflet widened part - Google Patents

Abstract

FIELD: building structures, particularly shallow foundations.

SUBSTANCE: method involves creating well by ground excavation, introducing preparatory portion of hardening material in well hollow including calculated part of hardening material; arranging explosive charge in lower well part; securing explosive charge; blowing explosive charge up to create cavity for widened foundation post part; crushing and widening above calculated part after explosion; introducing additional portion of hardening concrete in well up to 4/5 of well height; filling it with calculated part of above material portion. Concrete for casting is used as preparatory hardening material.

EFFECT: reduced time, increased simplicity of foundation building and reliability.

2 cl, 5 dwg

Description

The invention relates to the field of construction and can be used when arranging shallow foundations intended for installation of buildings and structures on them.

A known method of construction of the foundation, including the formation of a well by ramming, the formation at its end of the broadening with its filling by ramming hard material, filling the well with hardened material (USSR, AS 1735494, MKI: E 02 D 27/32, 27/28, publ. May 23, 1992, bull. No. 19).

The reason that impedes obtaining the desired technical result is the difficulty of implementing the method due to the need to introduce a support block, as well as tamping the material into broadening, which increases the time of construction of the foundation.

There is a method of erecting a shallow foundation columnar foundation, including the formation of a foundation pit by ramming the soil, creating broadening at its end, filling the broadening with concrete, filling the well with an additional portion in the form of set concrete (USSR, AS 844692, MKI: E 02 D 27 / 01, publ. 07/07/1981).

The reason that impedes the achievement of the required technical result is the complexity and duration of the implementation of this method, due to the creation and filling of the broadening by tamping hard concrete, as well as insufficient reliability due to the boundary between the hard broadening concrete and the set concrete of the well, which can lead to the sinking of the latter in broadening. In addition, the specified method does not provide for well reinforcement.

A known method of erecting a columnar foundation, including the formation of a well by excavating the soil, creating at the end of its broadening, concreting the broadening, introducing an additional portion of concrete into the well, reinforcing the well (USSR, AS 1021713, MKI: E 02 D 5/34, 5 / 58, publ. 06/07/1983, bull. No. 21).

The reason that impedes obtaining the required technical result is the complexity and duration of the foundation construction due to the need to introduce an additional structure into the wellbore, as well as the reduced bearing capacity due to the presence of an axial cavity in the concreted well and the absence of local compaction in the broadening area. In addition, the construction of the reinforced concrete structure in this way involves the use of it for foundations working in bending and, therefore, in tension, as a result of which it can be used for the construction of foundations with a depth of at least 5 m, and therefore cannot be used in shallow foundations.

The closest in essence and the technical result achieved is a method of erecting a shallow column foundation with camouflage broadening, including creating a well by excavating the soil, introducing a preliminary portion of subsequently hardening material into the well cavity, including the calculated part, and forming a broadening at the end of the cavity by placing it in the lower part of the borehole of the explosive charge and its subsequent explosion, collapse into broadening after the explosion of the calculated part of the preliminary parts of subsequently hardening material, the introduction of an additional portion of hardening concrete into the well (see, for example, Romanov D.A. Pile deep foundations, Kiev, Gosstroyizdat, 1959, p. 216-228).

The problem to which the invention is directed is to create a method for erecting a shallow foundation with high bearing capacity and not requiring a long time and complicated techniques and devices for erecting such a foundation.

The problem is solved due to the fact that the method of erecting a shallow column foundation with camouflage broadening involves creating a well by excavating the soil, introducing into the well cavity a preliminary portion of subsequently hardening material, including the calculated part, and the formation of a broadening at the end of the cavity by placing a charge in the lower part of the well explosive and its subsequent explosion, collapse into broadening after the explosion of the calculated part of the preliminary portion of subsequently hardening material , introducing into the well an additional portion of hardening concrete, according to the invention, a preliminary portion of subsequently hardening material is introduced to a height of not more than 4/5 of the length of the well, followed by filling in the calculated portion of the portion formed after the broadening explosion, and prior to the explosion of the charge, it is pre-fixed, and as a preliminary portion of subsequently hardening material, cast concrete is used.

In this case, before the introduction of a preliminary portion of cast concrete into the well, the foundation may be reinforced.

The technical result of the invention is to create a method based on the use of explosion energy, which allows for rapid filling of the broadening and accelerates the filling of the well, to ensure the reliability of the method by increasing the bearing capacity of the foundation by creating a monolithic interface between the broadening and the well, as well as providing local compaction in the broadening area and solidity filling wells.

The essence of the proposed method for the construction of a shallow foundation column foundation with camouflage broadening consists in the fact that the method includes creating a well by excavating the soil, forming broadening at its end, filling the broadening with hardening material, introducing an additional portion of hardening material into the well.

Operational implementation of the method is presented in the drawings, which depict:

figure 1 - well after removal of soil from it;

figure 2 - the introduction into the well of the reinforcing cage and the explosive charge;

figure 3 - the introduction into the well of a preliminary portion of concrete;

figure 4 - the collapse of the calculated part of the concrete in broadening after the explosion;

figure 5 - filling the well with an additional portion of concrete.

A method for erecting a shallow foundation column foundation with camouflage broadening involves excavating a well 1 by excavating it either by tamping it, or, for example, screw drilling using a tubular rod that receives rotation from a drilling rig (not shown in the drawing), displacing and removing loosened soil. After rising to the surface and removing the drilling unit, the explosive charge 2 is lowered into the formed cavity with electric detonators connected by electric drives 3 to an energy source (not shown in the drawing), fixed at the bottom of the well, for example, by mounting on a reinforcing cage 4, lowered into her. If necessary, the reinforcement cage is tensioned.

At the request of the customer, the foundation may not be reinforced, however, in any case, the charge 2 should be fixed relative to the bottom of the well to prevent the possibility of its subsequent floating up in the hardened material.

Then, a preliminary portion 5 of the hardened material is injected into the well through, for example, a hose, for which cast concrete or liquid glass, etc. can be used, to a height of not more than 4/5 of the height of the well, after which a charge of 2 explosives undermine and under the influence of the force of the explosion there is a local compaction of the soil, as a result of which a camouflage broadening is formed in it 6. At the same time, the shock wave of the explosion acts on the concrete column 5 located in the lower part of the well, raising it after which it falls under the influence of weight from above into the formed broadening cavity, filling its volume. With such a shock action, an additional concrete compaction occurs, which increases the bearing characteristics and broadening of the sole and column of the remaining part of the preliminary portion of concrete 5, the calculated part of which collapsed into broadening.

Filling a well with a preliminary portion of concrete to a height of not more than 4/5 is caused by the fact that when filling a well to a height of more than 4/5 and when exposed to the maximum allowable calculated value of the explosion energy, the concrete mixture may splash onto the earth's surface, which does not comply with safety conditions, therefore to prevent such a possibility, the column of the preliminary portion of concrete should not, as the experiment showed, exceed 4/5 of the height of the well. In addition, the aforementioned need to fill the well to a height of no more than 4/5 is caused by the need to reliably connect the broadening with the wellbore, as well as by the more effective effect of the explosion on the soil in the liquid concrete environment, while the explosion energy is used more fully, which allows not to take additional measures, associated with the need to seal the material itself.

Then, an additional portion of 7 concrete is added to the cavity of the well to the level of the soil surface.

The camouflage broadening volume is calculated on the basis of the difference between the concrete pillars before and after the explosion, and the mass of the explosive charge is calculated on the basis of the broadening diameter and geological conditions.

Based on the total shallow foundation foundation height of 1.6-2.0 m and the ratio of the laying depth to the width of the sole-broadening adopted for shallow laying, 2: 1 the width of camouflage broadening and the area of compacted soil around it allow these foundations to be classified as columnar foundations shallow laying.

When carrying out the invention, the possibility of achieving the specified technical result, which consists in accelerating and simplifying the known method of the prototype, as well as improving reliability by increasing the bearing capacity of the erected foundation of a shallow foundation erected by the claimed method, is confirmed by the use of known operations and techniques, as well as means and commercially available materials, including those presented at the level of functional generalization.

Claims (2)

1. A method of erecting a shallow foundation columnar foundation with camouflage broadening, including creating a well by excavating the soil, introducing into the well cavity a preliminary portion of subsequently hardening material, including the calculated part, the formation of a broadening at the end of the cavity by placing an explosive charge in the lower part of the well and its subsequent explosion, collapse into broadening after explosion of the calculated part of the preliminary portion of subsequently hardening material, the introduction of an additional portion of TV into the well concrete, characterized in that a preliminary portion of the subsequently hardening material is injected to a height of not more than 4/5 of the length of the well, followed by filling with the calculated portion of the portion formed after the broadening explosion, and prior to the explosion of the charge, it is pre-fixed, moreover, as a preliminary portion of the hardening subsequently the material is used cast concrete. 2. The method of erecting a columnar foundation according to claim 1, characterized in that before introducing into the well a preliminary portion of the cast concrete, the foundation is reinforced.

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