RU2539066C2 - Supporting element - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: supporting element includes tubular steel structures and a restricting device of transverse deformations. Tubular steel structures are provided with a multilayered winding of high-strength material wound on an outer surface and made in the form of a certain number of tubing strings connected to each other and forming an internal tight cavity relative to the environment, and the restricting device of transverse deformations is made in the form of a hydraulic pressure source interconnected with the internal cavity of the tubing strings, which is filled with liquid.

EFFECT: reducing metal consumption; enlarging functional capabilities.

2 dwg

Description

The invention relates to the field of construction and can be used to create antenna devices, tower structures and supports for placing various objects at heights of more than five hundred meters.

A well-known tower support, including tubular metal structures and a device for limiting lateral deformations (see, for example, Yu.V. Gaidarov "Pre-stressed metal structures". Publishing house of construction literature. L., 1971, p. 11). The metal structures are made of pipes welded together, connected by couplers, in part of which the transverse deformations of the support are limited by the creation of prestresses.

The disadvantages of the known supports are large metal consumption, due to the need to ensure the stability of the structure to weight and wind loads, as well as the high cost of manufacture, installation and operation.

In addition, the existing internal contradiction must be attributed to the shortcomings of all such structures: solving the stability problem leads to an increase in the mass and lateral surface area (windage) of the entire structure, which leads to an increase in weight and wind loads that pose a threat to this very stability. This contradiction limits the height of such structures and their bearing capacity.

These disadvantages are partially eliminated in another known support element, including tubular metal structures and a device for limiting lateral deformations (see, for example, Yu.V. Gaidarov, “Pre-stressed Metal Structures.” Publishing House of Construction Literature, L., 1971, p. 91 -93). The device for limiting lateral deformations is made in the form of sealed elements filled with compressed air.

A disadvantage of the known support element is the decrease in its reliability and safety with increasing air pressure necessary to ensure the desired stability of the structure, which leads to a limitation of the pressure and, as a consequence, the height of the designed structure.

The closest in technical essence and the achieved result is a known supporting element, including tubular metal structures and a device for limiting lateral deformations (see, for example, USSR author's certificate No. 1687848, F03D 11/04).

The device for limiting lateral deformations is a lever, the support of which is fixed on the tower of the wind turbine. The upper end of the coupler connected to the base of the tower by the lower end is pivotally mounted on the short arm of the lever. A wind-sensing organ is fixed on the long arm of the lever. When the wind acts on the wind-receiving organ, additional tension of the screeds occurs, causing an increase in the pressure of the lever on its support and an increase in the compressive load on the tower, which limits the lateral deformations of the latter.

A disadvantage of the known support element is the creation of compressive stresses in the tower, causing a decrease in longitudinal stability, which leads to an increase in metal consumption and limitation of the height of the structure.

The aim of the proposed technical solution is to reduce the metal consumption while expanding its functionality.

This goal is achieved by the fact that in the known support element, which includes tubular metal structures and a device for limiting lateral deformations, tubular metal structures are provided with a multilayer winding of high strength material wound on the outer surface of the pipes with an interference fit of each layer, and are made in the form of a number of interconnected tubing pipes forming an internal cavity sealed relative to the surrounding space, and a device for limiting lateral deformations - in the form of a source ka hydraulic pressure in communication with the internal cavity of the tubing filled with liquid.

The essence of the proposed technical solution is illustrated by the drawing, where figure 1 shows a longitudinal section of a support element; figure 2 is a diagram of the formation of additional area for calculating the magnitude of transverse strains.

The support element includes a number of tubing 1 (hereinafter tubing or pipe) connected to each other by means of couplings 2 in the column 3. The number of tubing 1 in the column 3 is determined by the required height of the constructed object. The upper pipe in the column is equipped with a threaded plug 4.

Instead of tubing 1 in the proposed technical solution, it is permissible to use drill or casing pipes manufactured by our industry.

On the outer surface of each pipe 1, including the sleeve 2, with a tightness of each layer, a multilayer winding 5 is made of high-strength material, for example, carbon, aramid fiber (in the form of a bundle, woven tape, etc.) or steel tape, which creates a preliminary compression stress in the wall of the pipe 1. After application, the winding 5 is fixed in a tensioned manner by any known method.

The lower pipe 6 in the column 3 is fixed in the foundation 7. The inner cavity of the tubing 1 is filled with hydraulic fluid, for example, oil and connected to a source of hydraulic pressure 8.

The support element operates as follows.

When the tightening torque of the tubing thread is more than 1000 N · m with the simultaneous use of antifriction-sealing grease, the threaded connections of tubing 1 with couplings 2, plug 4 and cup 6 become leak-tight and, after filling the internal cavity with hydraulic fluid, reliably maintain the generated internal pressure until it reaches the ultimate strength of the tubing wall. To increase the reliability of sealing, instead of antifriction-sealing grease, it is possible to use threaded joints of tubing 1 with couplings 2.

The system is pre-filled with oil when the top plug 4 is loose, which allows all air contained in the internal cavity of the pipes 1 of the column 3 to be removed. After the indicated volumes are completely filled, the threaded connection of the pipe 1 and the plug 4 is tightened.

Wind load on the side surface of the support element causes it to bend. In this case, the sections of the lateral surface of the column 3, located relative to the center of curvature of the bend farther than the curved axis of the pipe, are stretched, and closer to the axis of the pipe are compressed. Thus, an additional lateral surface is formed on the pipes outside the tubing axis (with respect to the center of curvature) and the corresponding surface inside the axis is reduced.

The oil pressure on the excess surface formed from the side of the wind load generates a counter-force distributed along the length, which tends to restore the straightness of the axis of the column, and limits the amount of transverse deformations, that is, the deflection of the support element.

This conclusion is especially significant if it is necessary to place any objects at heights of five hundred meters and above, when it is the windage of the object that poses insoluble problems that impede the implementation of projects. It is easy to verify that without creating excess pressure in the inner tubing cavity, a column with a height of more than 50 meters falls to the ground.

Below are the estimated estimates for determining the maximum deviation from the vertical of the free end of the column.

The following data and assumptions are accepted as initial data.

Estimated column height L = 1000 meters. The weight of the column together with the mass of the wound layer p = 18700 kg.

For the manufacture of tubing with upset ends: B - 89 × 8 - P GOST 633-80 (strength category "R"). Outer diameter D = 0.089 m, inner diameter d = 2r ₁ = 0.073 m, wall thickness s = 0.008 m, length l = 10 m. Yield strength σ _t = 930 MPa (9490 kg / cm ² ), elastic modulus E = 2,000,000 kg / cm ² , moment of inertia l _x = πD ³ / S = 221.47 cm ⁴ , distributed weight load q = 0.16 kg / cm.

The wound material is carbon fiber with a tensile strength (σ _p ) of at least 3.5 GPa (34300 kg / cm ² ) and elastic modulus E of at least 400 GPa. The thickness of the wound layer is 0.01 m. The outer diameter of the column is D _k = 0.109 m.

The magnitude of the working hydraulic pressure is p = 500 MPa (4900 kg / cm ² ).

The density of air averaged over the height of the column is p = 1.225 kg / m ³ and the kinematic viscosity coefficient of air is v = 15.2 × 10 ^-6 m ² / s (see, for example, G. A. Savitsky “Wind load on structures.” Publishing House literature on construction, M., 1972, p. 36).

Maximum wind speed υ = 60 m / s (216 km / h).

As an assumption, we assume that the shape of the bent axis of the pipe string in the presence of internal pressure is a circle.

Next, we determine the wind load:

$$F_{\mathrm{at}.}=c_x\cdot \rho \cdot {\mathrm{<figure-callout\; id="2"\; label="\upsilon "\; filenames="00000020.png"\; state="\{\{state\}\}">\upsilon </figure-callout>}}^2\cdot S_{P\mathrm{but}R}/2g,gde(\mathrm{one})$$

C _x = 0.2 is the drag coefficient of a long rough cylinder for Re = υ · D / v = 3.9 · 10 ⁵ (see ibid., P. 44, Fig. 3.8),

S _pairs - the projection area of the lateral surface of the tubing string, on a plane perpendicular to the direction of the wind,

S _steam = D _k · L = 0.109 · 1000 = 109 m ² .

Substituting the numerical values of the parameters in the formula (1), we obtain F _in = 4905 kg.

When the wind load acts on the lateral surface of the support element, it begins to bend relative to a certain center of curvature. The surface sections of the pipes 1 of the column 3, located relative to the center of curvature of the bend outside the bent axis of the column (from the convex side), are stretched, and those located inside (from the concave side) are compressed. Elastic tensile and compression deformations form on the column surface a figure close to a cylindrical segment, i.e. a geometric body cut off from a straight circular cylinder by a plane passing through the diameter of the cylinder base at an angle α (see Fig. 2, the cylindrical segment is shaded).

In this example, the cylinder is the inner surface of the tubing, and the secant plane is the extreme section of the BCD column, turned to the base of the ABC cylinder at a certain angle α, with its maximum deflection under the influence of the wind load. Due to the small curvature of the column under wind exposure, we neglect the “toroidality” of the cylindrical segment in question.

The cylindrical segment is formed by two identical "petals". One: ABDC (highlighted by vertical shading), - formed on stretched, and the second - on the compressed fibers of the pipe wall (not shown in figure 2). The area of the lateral surface of each of the “petals” (see, for example, G. M. Fichtengolts “The Course of Differential and Integral Calculus”, Volume 2, Publishing House of Science, Moscow, 1969, p. 222):

S _cyl. = d · h, where h = AD.

The area of the lateral surface of a cylindrical segment (two "petals") during bending is that unbalanced surface area, acting on which the oil pressure creates a force that counteracts the deviation of the axis of the column from a straight line. It must be remembered that this area of the lateral surface is evenly distributed along the length of the column, as a result of which the force opposite to the direction of the wind is a distributed load acting along the entire length of the supporting element.

The force compensating the wind load is the resultant of all pressure forces, which according to Pascal's law act in different directions, and is determined:

F _comp. = p · S _ave , where

S _Ave - the projection area B'C'D 'of the cylindrical segment on a plane perpendicular to the direction of the wind load (toned in figure 2).

The projection area of the two “petals” of the cylindrical segment ABDC is equal to twice the area of the semi-ellipse B'C'D ':

S _pr. = Π · A'B '· A'D' = πhd / 2.

The value of the segment AD = A'D '= h can be determined from the condition of equality of the wind load F _in. counteracting her effort F _comp. :

F _century = F _comp ;

h = 2F _in. / πdp = 9810 / π4900 7.3 = 0.087 cm.

Next, we determine the angle of rotation of the extreme section of the column α from the expression:

tgα = 2h / d = 0.0239 and α = 1.37 °.

Given the assumption about the shape of the bent axis of the column, we find the radius of curvature of column 3 using simple dependencies: C = 2πR and C = 360 · L / α, whence:

R = L · 360 / 2π · α = 1000 · 360 / 2π · 1.37 ° = 41822 m.

Finally, we determine the amount of deviation from the vertical of the upper end of the column under the influence of wind δ:

$$\delta =R(\mathrm{one}-\cos \alpha )=41822(\mathrm{one}-0,9999)=12m.(2)$$

The result shows that the proposed technical solution is able to drastically limit the deviation of the support element under the action of transverse loads from the longitudinal axis. In practice, the deviation will be even smaller, since it (in addition to the compensating force) limits the bending moment from the internal pressure force on the plug, arising when the axis of the clamped pipe is curved and, together with the moment of the compensating force, is aimed at restoring the straightness of the column axis.

Substituting in the expression (2) the central angle α ₁ = α / 100, we determine the deviation from the longitudinal axis of one pipe included in the column, δ ₁ = 0.12 cm. Let us compare this value with the maximum deflection under the own weight of the horizontally located cantilever pipe with pinched end. Deflection (see, for example, V.I. Anuryev, “A Handbook of a Mechanical Engineering Designer”, Volume 1, Mechanical Engineering, Moscow, 1980, p. 78): y _max = ql ⁴ / 8El _x = 45.15 cm.

Stresses at the pinched end of the pipe (see, for example, V.I. Feodosiev, “Resistance of materials,” M., Nauka, 1979, p. 131): σ ₁ = M out _. / W _x = 2ql ² / πD ² s = 1607 kg / cm ² .

That is, the stress in the seal is much less than the yield strength of the steel of which the pipe is made. And since in the elastic region the stresses are proportional to the strains, we can conclude with respect to the latter about the magnitude of the stresses in the embedment of the column: σ = σ ₁ δ ₁ / y _max = 4.27 kg / cm ² .

It can be seen from this that with real deflections of the column, the stresses at the clamped end are negligible compared to stresses from internal pressure.

Stresses in the column, taking into account the internal pressure, can be determined by the expressions (see, for example, S.V. Boyarshinov “Fundamentals of the construction mechanics of machines”, M., Mechanical Engineering, 1973, p. 64):

$${\sigma }_r=[(p_{\mathrm{at}n}\cdot r_{\mathrm{one}}^2-p_n\cdot {\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2)/({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2-r_{\mathrm{one}}^2)]-(p_{\mathrm{at}n}-p_n)r_{\mathrm{one}}^2{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2/({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2-r_{\mathrm{one}}^2)r;(3)$$

$${\sigma }_t=[(p_{\mathrm{at}n}\cdot r_{\mathrm{one}}^2-p_n\cdot {\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2)/({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2-r_{\mathrm{one}}^2)]+(p_{\mathrm{at}n}-p_n)r_{\mathrm{one}}^2{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2/({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2-r_{\mathrm{one}}^2)r;(\mathrm{four})$$

Where:

σ _r and σ _t are the radial and circumferential stresses;

p _vn and p _n - internal (working) and external pressure;

r ₁ , r ₂ and r are the inner, outer and current radii of the pipe.

Solving the problem of finding stresses, we divide it into stages, determining the stresses on each of them.

At the first, we consider separately the inner cylinder, loaded only with external pressure p _n . By external pressure in this example we mean the contact pressure p _k created in the pipe material by a high-strength material which is wound with interference. Tension is the tensile force in the material by which the winding is made.

Formulas (3) and (4) take the form:

; $${\sigma }_r=-p_{\mathrm{to}}\cdot {\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2/({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2-r_{\mathrm{one}}^2)\cdot (\mathrm{one}-r_{\mathrm{one}}^2/r^2)$$

;

; $${\sigma }_t=-p_{\mathrm{to}}\cdot {\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2/({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2-r_{\mathrm{one}}^2)\cdot (\mathrm{one}+r_{\mathrm{one}}^2/r^2)$$

;

.Stresses on the inner surface of the inner cylinder (in our pipe example): σ _r = 0; $${\sigma }_t=-p_{\mathrm{to}}\cdot 2{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2/({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2-r_{\mathrm{one}}^2)$$

.

Stresses on the outer surface of the inner pipe:

.σ _r = -p _k ; $${\sigma }_t=-p_{\mathrm{to}}\cdot (r_{\mathrm{one}}^2+{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2)/({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2-r_{\mathrm{one}}^2)$$

.

At the second stage, we consider separately the outer cylinder (in our example, the winding), for which the contact pressure p _k will be the internal pressure, r ₂ - the inner radius and R - the outer radius.

; $${\sigma }_r=p_{\mathrm{to}}\cdot {\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2/(R^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2)\cdot (\mathrm{one}-{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="00000020.png"\; state="\{\{state\}\}">R</figure-callout>}}^2/r^2)$$

;

; $${\sigma }_t=p_{\mathrm{to}}\cdot {\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2/(R^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2)\cdot (\mathrm{one}+{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="00000020.png"\; state="\{\{state\}\}">R</figure-callout>}}^2/r^2)$$

;

On the inner surface of the winding:

.σ _r = -p _k ; $${\sigma }_t=p_{\mathrm{to}}\cdot ({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2+R^2)/(R^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2)$$

.

On the outer surface of the winding:

.σ _r = 0; $${\sigma }_t=p_{\mathrm{to}}\cdot 2{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2/(R^2-r_{\mathrm{one}}^2)$$

.

At the third stage, we load the composite cylinder with working pressure and consider the stress state without taking into account contact pressure.

On the inner surface of the pipe:

.σ _r = -p _int ; $${\sigma }_t=-p_{\mathrm{at}n}\cdot (r_{\mathrm{one}}^2+R^2)/(R^2-r_{\mathrm{one}}^2)$$

.

On the outer surface of the winding:

.σ _r = 0; $${\sigma }_t=p_{\mathrm{at}n}\cdot 2r_{\mathrm{one}}^2/(R^2-r_{\mathrm{one}}^2)$$

.

Finally, we summarize the stresses acting at each of the studied points, and, substituting the numerical values of the parameters, we obtain.

On the inner surface of the pipe:

.σ _r = -p _ext = -9800 kg / cm ^2, $${\sigma }_t=-p_{\mathrm{at}n}\cdot (r_{\mathrm{one}}^2+R^2)/(R^2-r_{\mathrm{one}}^2)-p_{\mathrm{to}}\cdot 2{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2/({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2-r_{\mathrm{one}}^2)=6290\mathrm{to}g/\mathrm{from}{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="00000020.png"\; state="\{\{state\}\}">m</figure-callout>}}^2$$

.

On the outer surface of the pipe (inner surface of the winding):

.σ _r = -p _k = -3000 kg / cm ² , $${\sigma }_t=-p_{\mathrm{to}}\cdot ({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2+R^2)/(R^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2)-p_{\mathrm{to}}\cdot (r_{\mathrm{one}}^2+{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2/({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2-r_{\mathrm{one}}^2)=-7835\mathrm{to}g/\mathrm{from}{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="00000020.png"\; state="\{\{state\}\}">m</figure-callout>}}^2$$

.

.On the outer surface of the winding: σ _r = 0; $${\sigma }_t=-p_{\mathrm{at}n}\cdot 2r_{\mathrm{one}}^2/(R^2-r_{\mathrm{one}}^2)+p_{\mathrm{to}}\cdot 2{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2/(R^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2)=19442\mathrm{to}g/\mathrm{from}{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="00000020.png"\; state="\{\{state\}\}">m</figure-callout>}}^2$$

.

Circumferential stresses make up less than 65% of the yield strength of the pipe material, which is quite acceptable from the point of view of resistance to external compression.

Above, we did not consider axial stresses σ _z ; in a column that remain unchanged in any of the sections under consideration.

.Given the weight of the column itself: $${\sigma }_z=(p_{\mathrm{at}n}\cdot r_{\mathrm{one}}^2-P/\pi )/({\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="00000020.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2-r_{\mathrm{one}}^2)=19229\mathrm{to}g/\mathrm{from}{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="00000020.png"\; state="\{\{state\}\}">m</figure-callout>}}^2$$

.

Obviously, the pipe will not withstand such a tensile load. The maximum allowable tensile load on the tubing, taking into account the weight of the string, does not exceed 120 tons.

The solution to the problem is to increase the mass of attachments or other objects held by the proposed support element, up to 300 tons, for the sake of which the investigated object is proposed.

In the case of the use of the support element with insufficient mass of the payload, it is necessary to hang ballast on it or use additional ties placed in the inner cavity of the column 3 and connecting the plug 4 of the upper pipe 1 with the foundation 7 of the column. The internal method of placement allows you to not increase the windage of the support element and its wind load. Ties are made of the same carbon fiber as the outer winding 5.

Thus, the above estimates confirm the operability of the proposed technical solution that allows you to create objects that were previously impossible to manufacture.

Claims (1)

A supporting element including tubular metal structures and a device for limiting lateral deformations, characterized in that the tubular metal structures are provided with a multilayer winding of high-strength material wound on the outer surface, and are made in the form of a number of interconnected tubing that form an inner cavity that is sealed relative to the surrounding space and the device for limiting lateral deformations is made in the form of a source of hydraulic pressure communicated with internal morning cavity of tubing filled with liquid.

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