RU2318961C2 - Discharge device for cast-in-place pile production - Google Patents

Abstract

FIELD: construction, particularly to produce cast-in-place piles for constant and temporary foundation structure and artificial base building.

SUBSTANCE: device comprises capacitor bank connected with commutating discharge means. The discharge means have inner and outer coaxial electrodes and insulation arranged in-between. Electrodes have radial cuts. Inner electrode is made as stepped rod. Lower step of the rod has diameter exceeding that of upper one. Outer electrode is created as thick-walled pipe put on upper step of inner electrode so that space between electrodes is defined by lower end surface of outer electrode and surface of lower step formed in outer electrode and facing said end surface. Insulation extends over total cylindrical surface of upper step included in inner electrode.

EFFECT: improved pile reliability due to increased pile diameter by action application to hardening mortar to be poured in well in radial direction from well center, possibility to create charge sliding over insulation surface between accelerating electrodes.

2 cl, 2 dwg

Description

The invention relates to the field of construction and can be used in the construction of bored piles of permanent and temporary foundation structures and artificial foundations.

Bored piles are widely used to strengthen the overloaded bases of buildings and structures; construction of new facilities close to existing facilities; strengthening the foundations of existing buildings in connection with the reconstruction or increase of operational loads; correction of the building roll or individual foundations; landslide protection of buildings; reconstruction and construction in cramped conditions inside existing facilities; reinforcement of railway embankments with an unstable ballast train; construction of new facilities in difficult ground conditions.

A device for the manufacture of printed piles, for example, a device that impacts on a hardening material, which is an arrester consisting of electrodes connected by a high-voltage cable through a switch to a source of electrical energy - a capacitor bank (patent for invention RU No. 2100525 IPC E02D 5/34, 5/44).

At the same time, to carry out the impact, the capacitor bank is discharged to the emitting gap (active-inductive load), formed by two electrodes isolated from each other by a dielectric with the possibility of breakdown on the surface, for which a sliding discharge is formed.

The disadvantage of such devices is the instability of the response process, that is, the breakdown of the gap, and the lack of effectiveness on hardening material. This is due to the fact that the hardening material is mainly affected by the shock wave, the kinetic effect of which is insignificant due to the negative influence of electrodynamic forces on the arc plasma formed during the breakdown of the gap.

All of the above leads to high energy costs of the discharge station, to increase the charging operating voltage or to increase the number of storage capacitors.

Known devices that are stands for testing samples and products for the impact of strong magnetic fields and plasma (Lagutin A.S., Ozhogin V.I. Strong pulsed magnetic fields in a physical experiment. - M.: Energoatomizdat, 1988. - 192 p. .). Report “Recommendations on the use of injection piles. M., 2001 ”(information letters of State Unitary Enterprise NIIOSP No. 1-1025 of 11/19/99 and No. 38-345 of 03/15/01) Standard of the enterprise NIIOSP named after N.M. Gersevanova of the Gosstroy of Russia SP 38-2-01, with the help of which they also influence some objects, which can also be hardening solutions.

In addition, there are known stands for testing samples and products for the impact of a dense plasma, the designs of which use the method of cumulation of magnetic flux - “Filippov's plasma focus” (Strong and superstrong magnetic fields and their applications: Transl. From English / Ed. F .Herlakh. - M .: Mir, 1998 .-- 456 p., Ill.).

However, such designs do not allow the realization of shock, volumetric, directed action of a dense plasma on an object with stable high reliability and repeatability of the process.

The closest in technical essence to the claimed invention is a device for impact on any body, which may be a hardening solution containing a capacitor bank, a switching arrester, external and internal coaxial electrodes with interelectrode space and insulation between them, and the external electrode is made in the upper part in the form of a hollow hemisphere, the inner - in the form of a hollow truncated cone, while the interelectrode space is narrowed towards the focal point in the radial and axial measurements, and radial slots are made in the electrodes, the capacitor bank is connected symmetrically and axially to the electrodes (patent for invention RU No. 2196972, C 1, IPC 7 G 01 No. 3/317, G01M 7/08, dated 04.25.2001).

In this device, a radial, sliding, center-directed surface discharge occurs, in which the resulting arc plasma (plasma cord) is accelerated by electrodynamic forces, compresses the magnetic flux, followed by synchronous acceleration in the axial direction, before collapse at the focal point, which allows directed impact on body. The use of such a device allows a uniform plasma effect on the object, which may be a hardening solution.

However, the known device does not allow the directed action of the arc plasma on the object in a radial direction from the center, and therefore does not allow to obtain a pile with a diameter sufficiently large than the diameter of the well obtained after drilling. In this case, the hardening material can be highly compacted, which increases the strength of the piles. However, a sufficiently reliable pile having a diameter larger than a prefabricated well filled with a hardening solution cannot be obtained.

The technical result of the claimed invention is to increase the reliability of the manufactured piles by increasing its diameter by acting on the hardening solution placed in the well in a radial direction from the center, for which the structure is configured to form a sliding discharge on the insulation surface between the accelerating electrodes, and synchronously accelerate the arc plasma between them and the formation of a shock wave in the direction radial from the center. As a result of this, a shock-wave kinetic effect occurs on the hardening material and on the external forming wall of the well.

The specified technical result is achieved in that in the device for impact, containing a capacitor bank connected to a switching arrester with internal and external coaxial electrodes with insulation between them, and radial slots made in them, the inner electrode is made in the form of a stepped rod, the lower stage of which has a larger diameter than the top, and the outer electrode is made in the form of a thick-walled pipe, worn on the upper step of the inner electrode. In this case, the interelectrode gap is formed by the lower end surface of the outer electrode and the step surface of the outer electrode facing this end surface, and the insulation is placed along the entire cylindrical surface of the upper step of the inner electrode.

Figure 1 and 2 shows a diagram of the implementation of the inventive device, where 1 is an internal coaxial electrode, consisting of two stages, in the lower part made in the form of a cone, 2 - an external electrode made in the form of a thick-walled pipe, worn on the upper stage of the internal electrode so that the interelectrode gap is formed by the lower end surface of the outer electrode and the surface of the step of the outer electrode facing this end surface. A capacitor bank C is connected to a switching arrester P connected to the internal and external coaxial electrodes. Insulation 3 is placed between the electrodes and in the interelectrode space 4, and the electrodes are made with radial slots 5, and the capacitor bank is connected to the electrodes symmetrically and axially.

Radial, longitudinal slots 5, made in the electrodes, evenly spaced around the circumference, divide the electrodes into 4 parts. Longitudinal slots can be made more - 8, 10 etc. The insulation between the electrodes has no slots. The thickness of the outer tubular thick-walled electrode (that is, the arc plasma acceleration path “a-c” equal to the “b-d” section) is selected depending on the operation of the capacitor bank, on the speed of energy input into the load dW _co / dt, where W _co is the electrical energy stored in the capacitor bank; t is the discharge time.

The lower part of the inner electrode is made in the form of a cone in order to facilitate the movement and incorporation of the emitter into the concrete mixture.

The device operates as follows.

When a capacitor bank C is discharged through a switching arrester P, the discharge voltage is applied to the interelectrode gap 4. The portion of the insulation surface 3 located in this gap, through which the sliding surface discharge 6 passes, has the least electric strength in the gap 4. electrodes into separate sectors, a sliding discharge 6 occurs in each of the sectors of the electrodes at the same time and passes into the arc plasma 7. The reference points of the displacement plasma arc It floats on the electrode surfaces 1 and 2 in the gap 4 in the radial direction.

When the discharge current I flows through the electrodes, an electrodynamic force F arises, accelerating the arc plasma 7 beyond the electrode zone. Acceleration occurs due to the "panderomotor force" (according to the rule of the "left hand"). Moreover, for the device to work effectively, the condition must be met: breakdown voltage on the insulation surface between points “a-c” is less than breakdown voltage of the air gap 4 between points “c-d”.

Thus, due to the action of electrodynamic forces, the arc plasma 7 synchronously accelerates in the direction of the object of influence, which is the hardening material and the walls of the well. The synchronization of the formation and acceleration of the arc plasma 7 is realized by ensuring equal inductances of the sections of the interelectrode spaces 4, as well as by making radial slots, and the so-called “inductive divider” is formed).

Leading any plasma formation is difficult due to an increase in the inductance of the loop of this site. Thus, the plasma of all sections synchronously and equally accelerates and approaches the extreme sections of the interelectrode spaces with a “single front”. The object of exposure is subjected to electrodynamic, kinetic effects due to the accelerated plasma and the action of the shock wave.

Claims (2)

1. A device for impact, containing a battery of capacitors connected to a switching arrester with internal and external coaxial electrodes with insulation between them, and the electrodes are made radial slots, characterized in that the internal electrode is made in the form of a stepped rod, the lower stage of which is made large diameter than the top, and the outer electrode is made in the form of a thick-walled pipe, worn on the upper stage of the inner electrode so that the interelectrode gap is formed neither It end surface of the outer electrode and the surface of the lower stage outer electrode facing to the end surface, and the insulation is placed over the entire surface of the upper-stage cylindrical inner electrode. 2. The device according to claim 1, characterized in that the lower stage of the inner electrode is made conical in shape.

Images