RU1819309C - Method for construction of cast-in-place pile and reinforcing cage of cast-in-place pile - Google Patents

Abstract

SUMMARY OF THE INVENTION: The concrete mixture is compacted simultaneously with the compaction of the surrounding soil by subjecting the reinforcement cage to axial vibration shock, and part of the concrete mixture is laid in the well before the reinforcement cage is installed. Reinforcing frame includes longitudinal and transverse reinforcement. Part of the transverse reinforcement is made in the form of radial ribs and placed in diametrical planes with ruses along the length of the frame. 2 sec and 2 z.p. f-ly, 4 ill.

Description

The invention relates to the field of construction equipment and can be used to create pile foundations in the construction and reconstruction of buildings and structures, mainly in cramped conditions and unstable soils.

The aim of the invention is to increase the bearing capacity of piles.

The object of the invention is also achieved by the fact that in the reinforcing cage of a printed pile, including longitudinal and transverse reinforcement, part of the transverse reinforcement is made in the form of radial ribs placed in diametrical planes with beds along the length of the carcass. The presence of radial ribs limits the radial vibration of the reinforcing cage, which increases the intensity of impact on the ground

the base of the pile, and therefore its compaction.

In FIG. 1 shows a section through a pile during molding; in FIG. 2 - the same, in the process of tamping part of the concrete mixture into the soil of the well; in FIG. 3 - the same, after the completion of the formation of the pile shaft; in FIG. 4 is a section AA in FIG. 3 (concrete mix conditionally not shown).

The claimed method is implemented as follows.

A well with reinforced walls is created in the soil by any of the known methods. The walls of the well can be strengthened by firing or (as in the case under consideration) casing 1 (Fig. 1). The pipe is dipped into the ground with an open end in any known manner. Periodically by

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as it is immersed, or after immersion to the level of the pile sole, the pipe is cleared of soil. At the same time, layer 2 of the soil loosened during cleaning remains in the face, and underneath is the unconsolidated soil of the base. The reinforcing cage 4 is installed in the well (casing). The installation of the reinforcing cage 4 is carried out by means of a vibro-shock mechanism attached to the frame 4 by means of a transition device 12. After the installation of the reinforcing casing 4, the casing 1 is completely filled with concrete mixture 10 and the axial vibration impact is applied to the reinforcing casing 4. Under vibration, the concrete mixture 10 is compacted and rammed into the soil of the base.

In FIG. 2 shows the immersion of the reinforcing cage 4 in a portion of concrete mixture 3 with a height of 2-3 diameters of the casing 1, laid before installing the reinforcing cage 4,

When creating piles in water-saturated soils and intensive water flow into the casing, the dry concrete mixture is loaded under water to a height of 2-3 casing diameters in a sealed soft shell before installing the reinforcing cage. When the reinforcing cage is submerged under the influence of a vibro-shock load, the soft shell collapses and the dry concrete mix is moistened with surrounding water. Upon further exposure to the reinforcing cage by vibro-impact loading, the concrete mixture is rammed into the soil of the base, as a result of which a concrete plug is formed, which prevents further penetration of groundwater into the casing pipe. The remaining water is pumped out of the pipe, the trunk and concrete.

The reinforcing cage 4 may consist of a central perforated pipe 5 (Fig. 3), a head 6, overlapping part of the cross section of the casing 1 and made, for example, in the form of an annular washer, coaxially placed on the lower end of the pipe 5, and radial ribs 7 placed in the ди -diameter planes along the length of the central pipe 5. The central pipe 5 can be made of separate sections for ease of installation in cramped conditions. In this case, the ribs 7 are located at the joint level 8 of the pipe sections 5, reinforcing it. The holes 9 in the wall of the pipe 5 are evenly distributed over its surface and can have a round or oval shape elongated along the longitudinal axis of the pipe 5. The distance between the ribs 7 located in the same plane is selected so as to ensure the stability of the central pipe 5 when subjected to an impact load. The gap between the ribs 7 and the inner surface of the pipe 1 determines

the amplitude of the transverse vibrations of the reinforcing cage 4. After installing the reinforcing cage 4 and ramming, where necessary, parts of the concrete mixture 3 (Fig. 2) into the soil of the base pipe 1 are completely filled with concrete mix 10 and act on the reinforcing cage 4 with axial vibration.

Shock loading causes axial and lateral vibrations

reinforcement cage 4. The amplitude of the transverse vibrations of the cage 4 is determined by the gaps between the ribs 7 and the inner surface of the pipe 1 and the distance between the ribs 7 along the axis of the pile.

Axial and transverse vibrations of the frame 4 compact the concrete mixture 10. The presence of holes 9 in the central pipe 5 increases the intensity of dynamic effects on the concrete mixture, increases

uniformity and density of concrete mix. At the same time, under the influence of the shock load, the reinforcing cage 4 acts on the portion of the concrete mixture 3 located under the head 6. The presence of the tip 6, which breaks off part of the cross-section of the casing 1, increases the resistance to the introduction of the frame 4 into the portion of the concrete mixture 3, which leads to part of the concrete mixture 3 is pushed into the space above the head,

at a pressure exceeding the pressure of the column of concrete mixture 10, and the remaining part of the concrete mixture 3 is compacted and rammed into loosened soil 2, compacted, as well as the adjacent massif

natural soil.

At the base of the pile, a compacted core 11 is formed, which increases its bearing capacity.

One possible implementation of the proposed method in weak water-saturated soils based on loose coarse soil.

A casing pipe of 0325 mm and a length of 14.0 m is immersed in the ground with a pneumatic hammer

СО-166 (energy of a single blow of 1000 J). After the pipe is immersed before failure (the cessation of residual movements), it is cleaned of the soil by the pneumatic punch I P-4603 (energy of a single impact of 250 J). The pipe is cleaned to a height of 13.5 m, i.e. A soil plug 0.5 m high is left in the pipe. After filling the pipe to a height of 0.6 m with dry concrete mix, loaded in sealed plastic bags under the water entering

pipe, a reinforcing cage is installed in the form of a central perforated pipe 0159 mm with ribs and a head.

With a СО-134 pneumatic punch (unit impact energy of 500 J), the reinforcing cage is immersed until failure occurs and further exposure of the reinforcing cage with axial vibration shock allows the concrete to be rammed into the ground and compacted with a dirt plug. After that, water is pumped out of the pipe.

The casing and central perforated reinforcing cage pipe are filled with concrete. After laying the concrete mixture, the pneumatic punch is turned on for 5-10 minutes.

The impact of the axial vibrational load on the reinforcing cage, and through it on the concrete mix, makes it possible to uniformly and efficiently compact the entire concrete column filling the casing and compact the soil at the base of the pile.

This method provides a reduction in the volume and timing of work, which is especially important when reconstructing existing enterprises and operating residential buildings.

Application of the proposed method allows to increase the bearing capacity of piles by 20-40%.

Claims (4)

1. A method of erecting a stuffed pile, including forming a well with reinforced walls, installing a reinforcing cage, laying and compacting the concrete mixture, characterized in that, in order to increase the bearing capacity of the pile, the concrete mixture is compacted simultaneously with the compaction of the surrounding soil by acting on the reinforcing frame axial vibration shock. 2. A method according to claim 1, characterized in that part of the concrete mixture is laid in the well prior to the installation of the reinforcing cage. 3. The method according to claim 2, characterized in that. that a rigid mixture is used as a concrete mixture. 4. Reinforcing frame of a stuffed pile, including longitudinal and transverse reinforcement, characterized in that, in order to increase the bearing capacity of the pile, part of the transverse reinforcement is made in the form of radial ribs placed in diametrical planes along the length of the frame. 77772 77777 Figure 1 FIG. 2 eleven Fig.Z Aa Fig L