RU2676339C1 - Method of setting up bored piles - Google Patents

Abstract

FIELD: construction.SUBSTANCE: invention relates to the construction, in particular to the technology of manufacturing bored piles, and can be used to create pile foundations for underground and above ground multi-level buildings and structures for various purposes, including those erected in a semi-enclosed way in cramped conditions. Method of setting up bored piles includes the formation of a cylindrical well, filling a cylindrical well with concrete, using a punch to apply pressure to the concrete, creating broadening at the heel of the pile and immersing the reinforcement cage. Well is drilled under the protection of the casing and filled with movable concrete mix, then pressure is applied to the movable concrete mix, which is transmitted only to the heel of the pile, at the top of the casing. Area of the heel of the pile heel is estimated by the amount of the concrete mixture pressed into the ground and is determined by the dependence given. After compaction, immerse the reinforcement cage and add concrete mix to the design mark.EFFECT: technical result consists in ensuring the control of the broadening under the heel of the pile, increasing the bearing capacity of the bored pile.1 cl, 2 dwg

Description

The invention relates to the construction, in particular, to the technology of manufacturing bored piles, and can be used to create pile foundations for underground and ground multi-level buildings and structures for various purposes, including those being constructed in a semi-closed manner in cramped conditions.

There is a method of arranging reinforcing concrete cast ram piles with broadenings in the base of the foundation (RU No. 2506371, E02D 5/34, 02/20/2014), which includes performing a cylindrical well by rotational-translational immersion of the reamer to a predetermined depth with the displacement of soil in the near-wellbore space using a rolling mill and the formation of a sealed zone near the borehole space, followed by filling a cylindrical well with concrete mixture. Thus, a zone of a fixed base is formed in weak water-saturated soils.

The disadvantage of this method is the impossibility of its use in weak unstable and flooded soils, since the walls of the well located above the reamer remain loose and collapse.

The closest technical solution to the claimed invention is a method of arranging rammed concrete, reinforced concrete and reinforced concrete piles by arranging a rammed pile with a broadening, using a concrete casting device — a stamp, including making a cylindrical well by immersing the stamp to a predetermined depth with the soil being displaced into the near-bore space with its help and the formation of a compacted zone near the borehole space, filling a cylindrical well with concrete mixture under pressure, according loading and subsequent removal of the stamp is carried out by the indentation method, which includes stamping the wells by immersing the stamp to a predetermined depth and then filling the wells with concrete mixture under an overpressure of at least 2 atm, and the shape and cross section of the printed pile depend on the depth and number of re-immersion of the stamp by indentation in freshly laid concrete mix (RU 2610053, E02D 5/34, 02/07/2017).

The disadvantage of this method is the restriction of the use of indentation technologies near existing buildings and in weak unstable soils: the well walls located above the stamp remain loose and collapse.

The problem to which the present invention is directed, is to develop a method for the construction of bored piles, which allows to control the broadening under the fifth pile, which leads to an increase in the bearing capacity of the bored pile.

The technical result is achieved by the fact that in the method of installing bored piles, including the formation of a cylindrical well, filling a cylindrical well with concrete, using a stamp to apply pressure to the concrete mixture, creating broadening at the heel of the pile and immersing the reinforcing cage, the well is drilled under the protection of the casing and filled with a movable concrete mixture, then at the level of the top of the casing apply a stamp to the movable concrete mixture, transmitted only to the heel of the pile, to broaden the heel of the pile, the piles are estimated by the amount of concrete mixture squeezed into the ground and determined by the formula

where φ is the angle of internal friction of the soil under the fifth pile, degrees,

D is the diameter of the pile, m,

Z _ISM - the measured value of the squeezed concrete mixture into the ground, m,

after compaction, the reinforcing cage is immersed and the concrete mixture is added to the design mark.

The invention is illustrated by drawings, where in FIG. 1 shows a diagram of the application of pressure by a stamp and the formation of broadening of the heel of a pile;

in FIG. 2 - shows a diagram of piles with formed broadening.

The proposed method for the device of stuffed piles is as follows.

After the device of the cylindrical well 1, under the protection of the casing 2, the well 1 is filled with a movable concrete mixture 3, then at the level of the top of the casing 2 a stamp 4 is applied (for example, see GOST 20276-2012) pressure on the movable concrete mixture 3, transmitted only to the heel 5 piles, forming a broadening 6 at the heel of the 5th pile, since the casing 2 interferes with the penetration of the concrete mixture 3 into the lateral soil 2. The broadening area of the 6th heel 5 of the pile is estimated by the number of concrete mixture pressed into the soil and determined by the formula

where φ is the angle of internal friction of the soil under the fifth pile, degrees,

D is the diameter of the pile, m,

Z _ISM - the measured value of the squeezed concrete mixture into the ground, m

After compaction, the reinforcing cage 7 is immersed and the concrete mixture 3 is added to the design mark.

Let the pipe diameter be 630 mm, the internal friction angle be 20 °, and the measured height of the squeezed column of the concrete mixture be 38 cm. Then the area of the broadening of the heel of the pile

The area of the heel of the pile without broadening is

Thus, the bearing capacity under the lower end of the pile increased by about 2 times.

This method of installing bored piles allows you to control the broadening under the fifth pile, increasing the bearing capacity of the bored pile.

Claims (6)

A method of installing bored piles, including the formation of a cylindrical well, filling a cylindrical well with concrete, using a stamp to apply pressure to the concrete mixture, creating broadening at the heel of the pile and immersing the reinforcing cage, characterized in that the well is drilled under the protection of the casing and filled with a movable concrete mixture , then at the level of the top of the casing, apply a stamp on the movable concrete mixture, transmitted only to the heel of the pile, the area A of the broadening of the heel of the AI is estimated by the number of concrete mixture pressed into the soil and determined by the formula

where φ is the angle of internal friction of the soil under the fifth pile, degrees, D is the diameter of the pile, m, Z _ISM - the measured value of the squeezed concrete mixture into the ground, m, after compaction, the reinforcing cage is immersed and the concrete mixture is added to the design mark.

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