ES2539172T3 - Procedure for repairing a pole, in particular support of catenaries, and post repaired in this way - Google Patents

Abstract

Procedure for repairing a pole with an "H" section (1), in particular catenary supports, which has at least one weakened area (Z), in which two metal inserts (7a, 7b) are placed substantially parallelepiped facing each other, on both sides of the soul of the "H", as well as two metal plates (9a, 9b) on each wing (3a, 3b) of the "H", and these two inserts are fixed simultaneously (7a, 7b) and these two metal plates (9a, 9b) by means of a binding band of composite material (11) with a self-hardening resin matrix.

Description

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DESCRIPTION

Procedure for repairing a post, in particular of catenary support, and post repaired in this way.

The present invention relates to a method of repairing a post, in particular of catenary supports, and a post thus repaired. As is already known, the fixed electric traction installations (catenaries) for the power supply of the

railway material (locomotives) that circulate on railways are suspended to armaments that are in

themselves fixed to posts (catenary support). Classically, these posts are made of steel, frequently galvanized, and are of the HEA type, that is, they have a "H" section, simple or coupled.

The structure of these posts can be solid, or made of burlap. Each post is embedded in a solid concrete block poured into an excavation in the ground. This solid block is topped by a concrete protection pedestal that surrounds the base of the post. This protection pedestal, which allows to protect the base of the post against shocks from the ballast of

the railroad, presents inclined stones. This inclination allows to avoid the stagnation of rainwater around the base of the post. A common problem is the corrosion of these posts, and more particularly of their base that leaves the pedestal of

protection: certainly, in about twenty centimeters this base is very damaged, in particular when the protection pedestal is cracked and therefore retains water from the rains, which has the effect of gradually corroding the steel, and causing a mechanical weakening of the post.

The complete replacement of each post is very complex, since it is necessary to interrupt the circulation on the railway during the time of the works. In addition, such replacement is expensive, and highly consuming steel. There is therefore a real need, not for replacement, but for repair of corroded catenary posts. There are today two techniques to proceed with such repair.

A first technique consists of overmolding the base of the post with concrete. This technique is, however, expensive, and does not necessarily stop corrosion: there is a risk of seeing corrosion reappear at the interface of the post and concrete steel after a few years.

A second technique is to reinforce the base of the post with bolted supports. However, this technique has several drawbacks: it does not stop corrosion, it allows the efforts to be collected only on a single axis, it does not allow accompanying the expansions of the post (a game can then be created and the

bolts), there is a risk of unscrewing either by vibration or sabotage, and the realization needs very significant works. The present invention aims in particular to provide such a repair procedure. This objective of the invention is achieved with a post repair procedure having a section

in "H", in particular of catenary supports, which has at least one weakened area, in which two metal inserts are placed substantially parallel to each other, on both sides of the "H" soul, as well as two metal plates on each wing of the "H", and these two inserts and these two metal plates are fixed simultaneously by a band of composite material of self-hardening resin matrix.

The repair thus carried out constitutes a type of lateral hitch for the post, and it can be verified, during tests that will be described below, that the resistance provided by this side hitch is at least equal, even greater than that a post may present. new.

The placement of the two inserts and the two metal plates is optimal to obtain an isotropic resistance of the repaired post.

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According to other optional characteristics of the post according to the invention:

-eventually, dimensions for said metal inserts and said metal plates are selected so that these inserts and these plates protrude from the wings of the "H",

-a stress transmission putty is placed between said post and said insert: such putty allows an intimate union between this area and this insert, and therefore an optimal behavior against tensions to which the post is subjected,

-a stress transmission putty is arranged between said metal plates and said wings,

-a bicomponent resin is used, conditioned in dosage units,

-a bi-component putty is used, conditioned in dosage units.

The use of bicomponent products previously dosed allows to get rid of dosing operations, always delicate to perform in a work.

The present invention also relates to a "H" section post to which the repair procedure according to the above has been applied, comprising a weakened area, two substantially parallel parallelepiped metal inserts facing each other, arranged in said zone on both sides of the soul of the "H", as well as two metal plates arranged in said area on each cove of the "H", these inserts and these plates being fixed in said area by said band.

Other features and advantages of the present invention will appear in the light of the following description, and upon examination of the attached figures, in which:

-Figure 1 is a vertical sectional view of a catenary support post anchored in the ground, comprising at its base an area Z to be repaired,

Figure 2 is a cross-sectional view of the post of Figure 1, this section being made in the zone Z, according to line II-II of Figure 1,

Figure 3 is a sectional view along line III-III of Figure 2, of the post of Figure 1,

- Figures 4 and 5 show, in perspective views, two successive steps of carrying out the process according to the invention of repair of the post of Figure 1, in zone Z,

Figure 6 is a sectional view analogous to that of Figure 2 of the post of Figure 1 after repair in the Z zone, this figure corresponding to Figure 5,

- Figure 7 represents, schematically and in elevation, an installation that allows testing the resistance of the post of Figure 1 once it has undergone a repair according to Figures 4 to 6, and Figure 8 illustrates the value of the moment of inversion applied to the post (Y axis: unit in m-daN), depending on the angle of inversion of the post (X axis: unit in degrees), respectively for a new post, for a used and unrepaired post, for a post used and repaired according to the invention, with a first traction distance L, and finally for a second post repaired according to the invention, for a second traction distance L.

In the set of these figures, identical or analogous references designate identical or similar elements or sets of elements.

It now refers to Figure 1, in which a post 1, anchored in the ground S by means of a solid anchor block 2, preferably formed of concrete poured in an excavation has been represented.

The post 1 is preferably formed of galvanized steel, and has an HEA type section, that is to say substantially H-shaped, as can be seen in particular in Figure 2.

The dimensions of the section of the H profile forming the post 1 are, in the case of a railway application, given by the NF A 45-201 standard.

The post 1 is subject to corrosion, in particular in its zone Z located just above the solid anchor block 2.

When the protection pedestal is cracked, there is strong corrosion in the interface area between this pedestal and the base of the post.

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A loss of material in the two wings 3 of the profile forming the post 1 is thus very classically observed.

As can be seen in Figures 2 and 3, this loss of material, indicated by lines 5, typically takes place at a height hc of the order of about twenty centimeters, according to the profile indicated in Figure 3: loss of material that it is accentuated by going from the ground to about twenty centimeters above the ground.

This loss of material is critical, so much that it takes place in the zone of the post 1 in which the moment of flexion is the highest, when this post is subjected to various stresses, which include in particular the weight of the supported installation (catenary + catenary support arm), as well as the different external forces, and in particular those caused by the wind.

Under these conditions, it is understood that it is essential to make the zone Z of the post remain perfectly healthy, and that the amount of material necessary for the stability of this post is not affected.

Until now, one of the only really effective solutions was to simply and simply delete the used post 1, and replace it with a new one.

In addition, the fact that this solution requires a traffic stop on the railroad was of course costly, on the one hand in labor and material and, on the other hand in lost galvanized steel.

The present invention thus provides an economical, practical and elegant solution for prolonging the life of a post that exhibits wear on its base related to corrosion.

The method according to the invention consists in placing at least one insert and preferably two inserts 7a, 7b (see Figures 4 to 6), in each of the spaces defined by the two wings 3a, 3b of the profile of the post 1, in the zone Z.

The inserts 7a and 7b are preferably parallelepipedic, and preferably metal.

These inserts 7a and 7b can be sized in order to slightly exceed volumes defined by the two wings 3a and 3b, as can be seen in Figure 6.

Prior to the placement of these inserts in these volumes, the cavities defined by the two wings 3a, 3b of a stress transmission putty, preferably formed from two previously dosed components, are coated.

Once the two inserts 7a and 7b are positioned in the cavities defined by the two wings 3a and 3b, over a height that substantially corresponds to the corroded height hc (see Figure 3), they are added to the outside of the two wings 3a and 3b two metal plates 9a and 9b, the stress transmission putty previously coated on the outer faces of the wings 3a and 3b.

As can be seen in Figure 6, the two metal plates 9a and 9b can exceed the length of the wings 3a and 3b substantially of the same value as the two inserts 7a and 7b.

The configuration shown in figure 4 is thus achieved, in which the two inserts 7a and 7b on the one hand, and the two metal plates 9a and 9b on the other hand, were positioned in the corroded zone Z.

Next, the assembly thus formed is assembled by means of a composite material 11 (see Figures 5 and 6), formed of a layer of Kevlar® type fibers, impregnated with a self-hardening resin.

This self-hardening resin is preferably obtained by mixing two previously dosed components, the association of these two components performing a rapid polymerization that causes an extreme hardening of the bonding band of composite material 11.

By "self-hardening" is meant that the resin hardens due only to the mixing of the two components, without any input of external energy (heat or other).

It is understood that at the end of this repair, the post 1 is reinforced in its zone Z, by a set of metal materials on the one hand and composed on the other hand, which cooperate intimately and isotropically, and that remedy the material deficit caused by the corrosion of this post.

It is further noted that the performance of the process according to the invention is extremely simple, and requires very little material.

Figure 7 indicates an installation that allows to test the resistance of a post 1 to a force applied at its vertex.

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More precisely, this force T is applied by means of a cable 13 fixed to the ground S at a height e of this ground, and at a distance L from the foot of this post 1.

A pulling element 17, such as a cable strip, allows the value of the tension T applied 5 to the cable 13 to be gradually increased.

A dynamometer 19 allows measuring the value of this voltage T.

By way of illustration, and not limitation, tests have been carried out to characterize the reinforcement of a post 10 having a section of type HEA 200, for the following cases:

-a post whose base has been corroded and has not undergone any repair (post 2),

-first pole whose base has been corroded and has undergone a repair according to the method according to the invention (post 3 -traction distance L = 29.2 m), and

-second post whose base has been corroded and has undergone a repair according to the method according to the invention (post 4 -traction distance L = 28.8 m).

20 It is noted that such tests could also be performed for posts that have a different section of HEA 200.

The difference between the tests related to the last two posts lies in the differences in values of L (distance between the post 1 and the fixing point 15 of the cable 13 to the ground S).

For each of the four aforementioned posts, the test shown in Figure 7 is therefore carried out, in which the tension T is gradually increased by means of the cable strip 17.

An inclinometer 21 fixed to the post 1 makes it possible to measure the variation of the angle of the post 1 with respect to the vertical, as the tension T is increased by the cable tie 17.

By reading the corresponding voltage values in dynamometer 19, it has been possible to establish, for each of the four aforementioned posts, the graph represented in Figure 10.

35 Four curves C1, C2, C3, C4 are thus obtained, corresponding respectively to posts 1, 2, 3 and 4.

As can be seen in particular on the subject of post 2, each of curves C1 to C4 comprises on the one hand a substantially rectilinear part E and, on the other hand, a bent part P.

The substantially rectilinear part E corresponds to the elastic deformation of the post, and the bent part P corresponds to the plastic deformation, ie irreversible of this post.

The transition limit between the elastic and plastic parts of each of the curves C1, C4 is indicated respectively by references S1 to S4, in Figure 10.

As can be seen from the examination of Figure 8, posts 3 and 4, that is to say those that have undergone a repair according to the method of the invention, have clearly higher critical moments (respectively 12,000 and 12,000 m.da.N ) to (7300 m.da.N) of post 2 that has not undergone any repairs.

50 And what is even more amazing is that the critical moments of posts 3 and 4 are also superior to those of post 1, new.

As can be understood in light of the foregoing, the method according to the invention, simple and inexpensive to perform, and which does not need any complete replacement of the existing posts, allows to restore an excellent mechanical strength for a post that has suffered a major corrosion near its solid anchor block.

It has been further verified that the repair according to the invention offered an excellent guarantee of perenniality, in particular against external aggressions (ballast projection, rainwater, ultraviolet).

For all these reasons, the process according to the invention offers a very elegant solution, which allows new posts to be given new life for which there were no other solutions today than a replacement for an identical one.

Claims (5)

1. Procedure for repairing a post with a section in "H" (1), in particular of catenary supports, which has at least one weakened area (Z), in which two metal inserts (7a, 7b) 5 substantially parallel to each other facing each other, on both sides of the soul of the "H", as well as two metal plates (9a, 9b) on each wing (3a, 3b) of the "H", and these two are fixed simultaneously inserts (7a, 7b) and these two metal plates (9a, 9b) by means of a ligature band of composite material (11) with self-hardening resin matrix. Method according to claim 1, wherein dimensions for said metal inserts (7a, 7b) and said metal plates (9a, 9b) are chosen such that these inserts (7a, 7b) and these plates (9a, 9b) eventually protrude from the wings (3a, 3b) of the "H". 3. The method according to one of claims 1 or 2, wherein a 15-stress transmission putty is placed between said post (1) and said insert (7a, 7b). 4. Method according to any of the preceding claims, wherein a stress transmission putty is placed between said metal plates (9a, 9b) and said wings (3a, 3b). Method according to one of claims 3 or 4, in which a two-component putty, used in dosage units, is used. 6. Method according to any of the preceding claims, wherein a two-component resin is used, conditioned in dosage units. 25 7. "H" section post (1) to which the repair procedure has been applied according to any of the preceding claims, which comprises a weakened zone (Z), two metal inserts (7a, 7b) substantially parallelepipedically facing each other, arranged in said zone (Z) on both sides of the soul of the "H", as well as two metal plates (9a, 9b) arranged in said zone (Z) on each wing (9a, 9b) of the " H ", being These inserts (7a, 7b) and these plates (9a, 9b) fixed in said zone (Z) by means of said ligation band (11). 6