EP2884024B1 - Method for the renovation of masts produced using steel lattice construction - Google Patents

Description

The invention relates to a method for refurbishment in steel lattice construction manufactured masts, especially high-voltage overhead masts, with corner handles and with at least one foundation. - Below, instead of the term high voltage overhead mast or high voltage mast also briefly the term mast is used. It is within the scope of the invention that corner handles are arranged at four corners of the mast to be rehabilitated. These corner handles are usually embedded in a foundation designed as a concrete foundation.

Power transmission towers are used for the transmission and distribution of electrical energy. As a rule, these are steel grid constructions of a special kind, which are subject to stringent requirements with respect to their serviceability and safety. Failure of a power transmission tower will result in the failure of whole power transmission lines or power transmission lines of the electrical power supply. High-voltage overhead transmission towers must therefore comply with special regulations and are therefore monitored for serviceability and safety.

High-voltage overhead transmission towers are exposed to considerable compressive stresses, among other things. In the case of the bars of the grid structures loaded with pressure, the cross-section, the geometry (resistance moment) of the bars and the buckling length must be taken into account. If in the grid construction diagonal bars are overloaded with pressure, they can be easily replaced by stronger profiles. But if corner handles of the grid construction are overloaded with pressure, replacement of the corner handles is practically impossible or would be the same as a new building.

In practice, various remedial methods have been used for pressure overloaded corner posts of such grid structures. For example, it is known to reinforce the individual overloaded fields of the grid structures with additional profiles. By means of a large number of on-site fitting bores an existing profile is thus reinforced in its cross-section and its moment of resistance. These measures are very complex and, above all, labor-intensive. - In another refurbishment variant, an additional corner post is arranged parallel to the existing corner post over larger mast sections. The additional corner handle is moved to the old existing corner handle and connected with binding plates with the old corner handle. The binding plates are drilled on site with the existing corner handle and connected with screws. For example, if you want to relieve the existing corner stalk by 50%, the new additional corner stalk must have the same cross-section as the old corner stalk. These known measures are also expensive or expensive.

Methods for reinforcing masts made in steel lattice construction, according to the prior art, are known, for example, from the following documents: DE865360C . EP1335083A1 and JP2000192672A ,

In contrast, the invention, the technical problem of providing a method of the type mentioned, in which the above-mentioned disadvantages can be effectively avoided and with the rehabilitation of pressure overloaded corner posts of masts, especially high-voltage overhead masts in a simple, inexpensive and effective way can be realized.

The solution to this problem is obtained by the features specified in claim 1.

To solve this technical problem, the invention teaches a method for the renovation of masts produced in steel lattice construction, in particular high-voltage overhead masts, with corner posts and at least one foundation, wherein at least one Zusatztsststiel is arranged parallel or substantially parallel to an existing corner stem, wherein the Zusatzstalk at its ends or in the region of its ends frictionally with the existing Eckstiel is connected and wherein a biasing pressure force is introduced into the Zusatzstestiel. It is within the scope of the invention that the preload pressure force is applied in the longitudinal direction of the additional stalk or substantially in the longitudinal direction of the additional stalk. It is also within the scope of the invention that the Zusatzstestiel is first connected at one of its ends or in the region of one of its ends frictionally with the already existing Eckstiel, that then the biasing pressure is introduced into the Zusatztsststiel and that then the Zusatzeckstiel with its other end or in the region of its other end is non-positively connected to the existing corner handle.

The invention is based on the finding that the method according to the invention makes it possible to clean up or relieve existing pressure-bearing corner posts of masts, in particular overhead power transmission towers, in a simple, functionally reliable and effective manner. - It is within the scope of the invention that a mast to be rehabilitated has four corners with corresponding corner stems. In principle, all corner handles can be rehabilitated by the method according to the invention. The already existing to be rehabilitated corner handles can be of different types or shapes. So it can be angle profiles, butterfly profiles, corner handles in the form of bolted angle profiles and the like. According to a preferred embodiment of the invention, a plurality of additional stalks according to the invention are arranged one above the other at a corner of the mast to be rehabilitated and preferably each additional stalk is treated in the sense of the method according to the invention.

Conveniently, the biasing pressure force is applied at the end or in the region of the end of a Zusatzeckstieles. Empfohlenermaßen it is the biasing pressure of at least one on one end of Zusatzeckstieles acting pressurizing device, in particular applied by a pressurizing cylinder and preferably by a hydraulic cylinder. A hydraulic flat cylinder has proven particularly useful. A particularly preferred embodiment of the invention is characterized in that the preloading pressure force is applied to the lower end of the additional stalk. - Appropriately, it is worked in the context of the method according to the invention with the proviso that the height of the biasing pressure and the cross section of the Zusatztsststs not exceed the static limit stresses at maximum load and thus as it reaches an economic optimum.

It is recommended that an additional handle is used, which has a receptacle or a receiving device for receiving or for mounting the pressurizing device, in particular the pressurizing cylinder. It is within the scope of the invention that the prestressing pressure forces to be applied during the pretensioning of the additional stalk are between 20 kN and 1500 kN. The individually applied biasing forces are dependent on the type of mast.

Conveniently, the additional handle is held or guided at least during the pressurization or during assembly with at least one clamping and / or holding device on the associated existing corner handle. The clamping and / or holding devices are preferably designed so that the additional stalk is arranged parallel or substantially parallel to the existing corner handle. The at least one clamping and / or holding device secures the additional stalk in particular against lateral buckling during the pressurization. The clamping and / or holding device or the clamping and / or holding devices are recommended, designed with the proviso that a relative movement between Zusatzstalk and existing corner stem is possible, so that in particular a change in length of Zusatzeckstiels due to the pressurization is possible without hindrance. It is within the scope of the invention that a plurality of clamping and / or holding devices is arranged distributed over the length of the additional stalk or over the length of the existing corner stalk.

A recommended embodiment of the method according to the invention is characterized in that during the pressurization of the additional stalk, the heavy axis S of the additional stalk is located in the central axis or in the longitudinal central axis of the pressurizing device / the pressurizing cylinder or the hydraulic cylinder or substantially in the central axis or in the Longitudinal axis of the pressurizing device, in particular of the hydraulic cylinder is located. Thus, the center of gravity of the additional stem is as it were above the center of the pressurizing device or the hydraulic cylinder. In principle, it is within the scope of the invention that the heavy axis S of the additional handle can be adjusted for this purpose by fixing, in particular by welding spacers. This is especially true for smaller additional stalks. In that regard, within the scope of the invention, a shift of the center of gravity of the additional handle can take place over the pressurizing device.

It is within the scope of the invention that after the pressurization of the additional stalk, the resulting change in length or length reduction of the additional stalk is fixed with at least one fixing device. The change in length or length reduction of Zusatzeckstiels is thus frozen as it were within the scope of the invention. So can take place in a very effective way relieving the pressure applied to the pressure or overloaded existing Eckstiels. A particularly preferred embodiment of the method according to the invention is characterized characterized in that the fixing device for fixing the change in length or length shortening of the additional stalk has at least one threaded pin connected to the additional stalk or at one end of the additional stalk. Empfohlenermaßen this threaded pin is located at the lower end of the additional stalk. Preferably, at least one nut and at least one lock nut is mounted on the threaded pin, with the mother or with the lock nut, the change in length or length reduction of Zusatzzckstiels can be fixed. Conveniently, the at least one threaded pin is arranged in the gravity axis or on the gravity axis or as close as possible to the axis of gravity of the additional handle. - A proven embodiment of the method according to the invention is characterized in that the pressurizing / pressurizing cylinder or the hydraulic cylinder between a lower biasing plate and an upper biasing plate is inserted or is arranged, preferably the threaded pin passes through the upper biasing plate. It is within the scope of the invention that the lower biasing plate and the upper biasing plate are fixed to the existing Eckstiel to be rehabilitated. Conveniently, a recess for the threaded pin is provided in the upper biasing plate, so that the threaded pin can pass through the upper biasing plate. Empfohlenermaßen the nut or lock nut are screwed against the upper biasing plate when fixing the change in length or length reduction of Zusatzeckstiels.

According to a particularly recommended embodiment of the invention, after the pressurization of the additional stalk, the additional stalk is connected to the associated existing corner stalk via connecting elements, such as connecting plates or the like. The connection takes place in this case, with the proviso that no or virtually no relative movement between Zusatzstalk and existing corner stalk more is possible. It is within the scope of the invention that are introduced for fixing or connection with the connecting elements bores and fittings in the existing corner handle or in the additional stalk. Conveniently, the connecting elements or connecting plates are arranged at certain intervals on Zusatzeckstiel or on the existing corner post, which are characterized by the moments of resistance of the existing Eckstiels and Zusatzeckstiels.

According to the invention, the pressurizing device, in particular the hydraulic cylinder is removed after the pressurization of the additional stalk and expediently after fixing the change in length or length reduction of Zusatzzeststiels. The pressurizing device is preferably removed from the space between the lower biasing plate and the upper biasing plate. Thus, the pressurizing device can be used for other corresponding purposes. It is also within the scope of the invention that the preloading pressure force can be subsequently checked or checked with a pressurizing device or with a pressurizing cylinder or the like. It is preferred that this biasing force can be checked or checked as possible at any time.

A recommended embodiment of the invention is characterized in that the additional stalk used has the same modulus of elasticity and / or the same coefficient of thermal expansion as the associated already existing corner stalk. This embodiment has proven particularly useful in the context of the method according to the invention.

It is within the scope of the invention that a Zugschutzeinrichtung is arranged on the Zusatztsststiel. For example, in the case of strong gusts of wind, the auxiliary stalk normally under compressive stress can also be subjected to tensile stresses. However, these tensile stresses only occur if the tensile forces acting on the additional stalk exceed the preloading pressure force of the additional stalk. While the fixing device ensures the compressive stress even after pressurization, so the Zugschutzeinrichtung serves the reverse case. It ensures that with the occasional tensile stresses on the additional stalk, the corner stalk is relieved not only under pressure but also under high tensile stresses.

According to a recommended embodiment of the method according to the invention, the Zugschutzeinrichtung preferably comprises a nut and a lock nut. In this case, mother and lock nut of the Zugschutzeinrichtung have the same thread as the nut and lock nut of the fixing device and thus also fit on the threaded stem of Zusatzzeststem. In contrast to nut and lock nut of the fixing device, however, nut and lock nut of the Zugschutzeinrichtung are bolted from below against the upper biasing plate. Thus, the additional stalk is fixed in both directions of movement of the threaded pin in relation to the upper bias plate and a part of any occurring large tensile stresses is diverted to the additional tip.

The invention is based on the finding that with the method according to the invention a very simple, inexpensive and nonetheless functionally reliable and effective relief of a pressure applied to a corner handle or a pressure overstressed corner handle can be achieved. The method advantageously has short assembly times. The Number of holes to be introduced is relatively low compared to known from the prior art measures. Elaborate fitting and fitting screws are largely unnecessary. It is also advantageous in the context of the method according to the invention that an integration of the pressure relief components into the foundation of the mast is eliminated. The inventive method is further characterized by relatively low cost. It can be readily realized on most known masts, especially overhead power transmission towers.

Fig. 1

eine Seitenansicht eines nach dem erfindungsgemäßen Verfahren sanierten Hochspannungsfreileitungsmastes eines ersten Ausführungsbeispiels,

Fig. 2

einen vergrößerten Ausschnitt A aus der Fig. 1 und

Fig. 3a, b

einen vergrößerten Ausschnitt B aus der Fig. 2 in schematischer Darstellung in zwei Funktionsstellungen,

Fig. 4

ein zweites Ausführungsbeispiel des erfindungsgemäßen Verfahrens.

The invention will be explained in more detail with reference to a drawing illustrating two embodiments. In a schematic representation:

Fig. 1

a side view of a rehabilitated by the novel high voltage overhead mast of a first embodiment,

Fig. 2

an enlarged detail A from the Fig. 1 and

Fig. 3a, b

an enlarged detail B from the Fig. 2 in a schematic representation in two functional positions,

Fig. 4

A second embodiment of the method according to the invention.

The Fig. 1 to 3b illustrate a method according to the invention for the rehabilitation of masts produced in steel lattice construction 1, in particular high-voltage overhead transmission towers based on a first embodiment.
The masts 1 have corner handles 2 and a foundation 3. Appropriately, and in both embodiments, the mast to be rehabilitated 1 is in Cross-section square or rectangular and thus has four corners with corner posts 2.

According to the invention, additional stems 4 are arranged parallel to the existing corner stems 2 at the corners of the mast to be rehabilitated. The Zusatzeckstiele 4 are finally connected at their ends 5, 6 each frictionally with the associated corner stem 2. Preferably, and in both embodiments, at each corner of the mast 1, a plurality of each at their ends 5, 6 associated with the associated corner handle 2 Zusatztsstehren 4 are arranged one above the other. According to the invention, a preloading pressure force is further introduced into one or each additional stalk 4.

Preferably, and in both embodiments, a Zusatzeckstiel 4 is initially connected with its upper end 6 frictionally with the associated existing corner stem 2.

According to a preferred embodiment and in both embodiments, the biasing pressure force is applied by a respective acting on the lower end 5 of the Zusatzsteststs 4 pressurizing device 7 in the form of a hydraulic cylinder 8. As hydraulic cylinder 8, a hydraulic flat cylinder is preferably used. It is within the scope of the invention that a prestressing force of between 20 kN and 1500 kN is applied to a supplementary stalk 4. In this case, the applied in each case biasing force depends on the type of mast 1 and the power transmission tower mast. Due to the application of pressure or by the application of the preload pressure force, the additional stalk 4 is compressed or shortened in its length. He experiences a change in length Δl.

Empfohlenermaßen and in both embodiments is worked with a Zusatzeckstiel 4, which has a receptacle 9 for receiving or for mounting the pressurizing device 7 in the form of the hydraulic cylinder 8. Conveniently, the receptacle 9 is provided for an actuating rod 18 of the hydraulic cylinder 8.

According to a particularly preferred embodiment and in both embodiments, a Zusatzeckstiel 4 is held or guided during the pressurization or during assembly activity with at least one clamping and / or holding device 10 on the associated existing corner handle 2. In both embodiments, this clamping and / or holding device 10 consists of a support plate 19 connected to the additional tip 4 with slot 20. In this slot 20 of the holding plate 19 summarizes a connected to the existing corner post 2 bolt 21 a. In this way, the pressurized additional stalk 4 is guided as it were on the existing corner handle 2 and secured against lateral buckling. The slot makes doing a relative movement of the additional stalk 4 to the existing corner handle 2 in the pressurization possible.

In the figures, it can also be seen that during the pressurization of the additional stalk 4, the heavy axis S of the additional stalk 4 lies in the central axis or in the longitudinal central axis L of the pressurizing device 7 in the form of the hydraulic cylinder 8. With the help of spacers, not shown, or the like, the center of gravity or the heavy axis S of the additional handle 4 can be adjusted accordingly or the center of gravity or the heavy axis S are displaced accordingly.

According to a particularly preferred embodiment of the invention, the pressurization of Zusatzeckstiels 4 or the resulting change in length Δl or length shortening of the additional stalk 4 with a fixing device 11 fixed or frozen. Empfohlenermaßen and in both embodiments, this fixing device 11 has a connected to the additional stalk 4 and at the lower end 5 of the additional stalk 4 threaded pin 12. Appropriately, and in both embodiments, at least one nut 13 and a lock nut 14 is arranged on this threaded pin 12 respectively. With this nut 13 and with the lock nut 14, the change in length .DELTA.l or the length shortening of the additional handle 4 can be fixed or frozen. For this purpose, nut 13 and lock nut 14 can be tightened in a conventional manner. Conveniently, the threaded pin 12 is arranged in or as possible on the gravity axis S of the additional handle 4.

Preferably and in both embodiments, the pressurizing device 7 is inserted or arranged in the form of the hydraulic cylinder 8 between a lower biasing plate 15 and an upper biasing plate 16. Expediently, and in both embodiments, the threaded pin 12 of the additional handle 4 passes through the upper biasing plate 16. When actuating the hydraulic cylinder 8 and pressurizing the additional handle 4 from below, the hydraulic cylinder 8 acts with its actuating rod 18 on the receptacle 9 of the additional handle 4. As a result, the additional handle 4 is compressed or shortened in its length so that it undergoes a change in length .DELTA.l. By tightening the nut 13 and the lock nut 14 on the threaded pin 12 of the additional handle 4 against the upper biasing plate 16, the length reduction .DELTA.l the Zusatztsststs 4 can be fixed or frozen as it were.

It is within the scope of the invention that after the pressurization of the additional stalk 4 of this additional stalk 4 with the associated existing Corner stem 2 is connected via non-illustrated fasteners, such as connecting plates or the like. - According to a preferred embodiment of the invention, the pressurizing device 7 and the hydraulic cylinder 8 is removed after the pressurization of the additional stalk 4 and expediently after fixing or after the freezing of the change in length .DELTA.l of the additional stalk 4. Then, the hydraulic cylinder 8 can be used for other purposes.

In the second embodiment, shown in FIG Fig. 4 , a Zugschutzeinrichtung 22 is additionally provided on the additional stalk 4. The hydraulic cylinder 8 has already been removed here. During storms occurring at the storm-facing sides of the mast 1 tensile stresses can exceed the pressure on the additional stalk 4. In these cases, lock nut 13 no longer presses on the upper bias plate 16 because the threaded post 12 has moved upwardly relative to the upper bias plate 16. This movement is prevented by the Zugschutzeinrichtung 22. As a result, the additional stalk 4 also assumes part of the tensile stresses on the corner stalk 2.

Preferably, the Zugschutzeinrichtung 22 includes a nut 23 and a lock nut 24. These also fit on the threaded pin 12, but are arranged below the upper bias plate 16. Thereby, a movement of the threaded pin 12 is suppressed in relation to the upper bias plate 16 upwards and it will be large tensile stresses transmitted to the additional stalk 4.

Claims (12)

1. A method for the restoration of masts (1) manufactured in a steel lattice form of construction, in particular high-voltage overhead line masts, with corner posts (2) and at least one foundation (3), wherein at least one ancillary corner post (4) is arranged parallel to, or essentially parallel to, a corner post (2), wherein the ancillary corner post (4) is connected in a force fit at its ends (5, 6), or in the vicinity of its ends (5, 6), with the corner post (2),
   characterised in
   that a compressive force preload is introduced into the ancillary corner post (4) and the compressive force preload is applied by a compressive force application device (7) acting on at least one end (5, 6) of the ancillary corner post (4), wherein after the application of compressive force to the ancillary corner post (4) the reduction in length of the ancillary corner post (4) is fixed with at least one fixing device (11), and wherein after the application of compressive force to the ancillary corner post (4) and after fixing the reduction in length of the ancillary corner post (4) the compressive force application device (7) is removed.
2. The method in accordance with claim 1, wherein the compressive force preload is applied at the lower end (5) of the ancillary corner post (4).
3. The method in accordance with one of the claims 1 or 2, wherein the operation is carried out with an ancillary corner post (4), which has a seating (9), that is to say, a seating device for accommodation, that is to say, for installation, of a compressive force application device (7).
4. The method in accordance with one of the claims 1 to 3, wherein a compressive force preload of between 20 kN and 1,500 kN is applied to the ancillary corner post (4).
5. The method in accordance with one of the claims 1 to 4, wherein the ancillary corner post (4) is held and guided, at least during the application of compressive force, with at least one clamping and/or holding device (10) on the associated corner post (2).
6. The method in accordance with one of the claims 1 to 5, wherein with the application of compressive force on the ancillary corner post (4) the axis through the centre of gravity (S) of the ancillary corner post (4) lies in the central axis, that is to say, the longitudinal central axis L, of the compressive force application device (7), or more particularly, the compressive force application ram, or essentially in the central axis, that is to say, the longitudinal central axis L, of the compressive force application device, or more particularly, the compressive force application ram.
7. The method in accordance with one of the claims 1 to 6, wherein the fixing device (11) has at least one threaded pin (12) connected with the ancillary corner post (4), that is to say, at one end (5, 6) of the ancillary corner post (4), wherein at least one nut (13) and at least one locking nut (14) are arranged on the threaded pin (12), with which the alteration in length, that is to say, the reduction in length, is fixed.
8. The method in accordance with one of the claims 1 to 7, wherein the compressive force application device (7), or more particularly, the compressive force application ram, is deployed, that is to say, arranged, between a lower preload plate (15) and an upper preload plate (16), wherein the threaded pin (12) preferably passes through the upper preload plate (16).
9. The method in accordance with one of the claims 1 to 8, wherein after the application of compressive force to the ancillary corner post (4), the ancillary corner post (4) is connected with the associated existing corner post (2) by means of connecting elements, such as connecting plates (17), or similar.
10. The method in accordance with one of the claims 1 to 9, wherein the ancillary corner post (4) that is deployed has the same modulus of elasticity, and/or the same thermal expansion coefficient, as the associated existing corner post (2).
11. The method in accordance with one of the claims 1 to 10, wherein the compressive force preload can be checked, or subsequently checked, with a compressive force application device (7), or similar.
12. The method in accordance with one of the claims 1 to 11, wherein a tension protection device (22) is arranged on the ancillary corner post (4), which tension protection device (22) preferably comprises a nut (23) and a locking nut (24).

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