RU2352711C2 - Antirust protection system for structures comprising stay ropes - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: antirust protection system for structures comprising stay ropes includes multiple assemblies operated under tension, each of which consists of parallel steel elements passing between the first and second anchor attachments and incorporates two opposite ends, the first and second ones. Note that the said first end interacts with the first anchor attachment, while the second one interacts with the second anchor attachment. The antirust protection system uses the tensions element not furnished with permanent antirust protection and called "unprotected elements operated under tension". The said system comprises multiple stay pipes enveloping the assembly operated under tension, each consisting of unprotected elements operated under tension. It includes also a drying device allowing producing air with the preset mean humidity content, that is, the so-called, "dry air", designed to feed dry air from the drying device into preset points, each arranged on one of three devices, namely, on the first anchor attachment, second anchor attachment and multiple stay pipes, a ventilation device to force dry air into the pipes from the said multiple dry air feed pipes and test, measurement and control appliances.

EFFECT: antirust protection system not increasing diameter of all operating elements operated under tension and making assembly to be operated under tension, continuous control of aforesaid system.

20 cl, 3 dwg

Description

The present invention relates to corrosion protection for structures containing cables.

A cable stay, in particular, but not exclusively, means a cable used to create suspension or cable-stayed structures, such as suspension bridges, cable-stayed bridges, roofs of stadiums, buildings, telecommunication towers, etc.

The present invention also relates to a cable-stayed structure, for example a cable-stayed bridge, which comprises the aforementioned corrosion protection system. Cable-stayed bridge generally includes:

- a bridge web that contains a structural unit, for example a metal structural unit, having, as an example, at least one inner chamber;

- at least one pylon containing at least one substantially vertical element, each pylon comprising a first part extending under the bridge web and a second part extending over the bridge web; and

- a lot of nodes working in tension, each of which:

- consists of parallel tensile steel elements; and

- passes between the anchor fastening of the bridge web located on the bridge web and the anchor fastening of the pylon located on said second part of the pylon.

A long cable-stayed bridge can contain hundreds of nodes working in tension, and the presence of such a large number of these nodes leads to a serious problem, namely, that the effect of the wind creates wind loads that are transmitted to the rest of the structure. In particular, it is necessary to increase the mechanical resistance of the bridge and pylon, as a result, the cost of construction increases.

Due to the fact that the magnitude of the wind loads depends on the diameter of the nodes working in tension, one of the objectives of the present invention is to reduce the said diameter.

In general, tensile steel elements used in the construction of cable-stayed bridges are protected against corrosion (for many years) by a grease layer and a sheath that surrounds the grease layer. The presence of a grease layer and a sheath increases the diameter of the core.

An increase in the diameter of each of the tensile elements constituting the tensile assembly substantially increases the diameter of this assembly.

One of the objectives of the present invention is to propose a corrosion protection system, which, in particular, eliminates this disadvantage.

Another objective of the present invention is to provide continuous monitoring of the state of the corrosion protection system.

To this end, it is proposed, on the one hand, to use tensile elements that do not provide permanent corrosion protection during manufacture (for example, are not coated with grease and sheath in the usual way) and which are called "unprotected tensile elements", and on the other hand, use a corrosion protection system that contains:

- a lot of cable-stayed pipes, each of which freely surrounds the tensile assembly, which consists of unprotected tensile elements;

- a dehumidification device that allows you to get air with a predetermined average level of humidity, which is called "dry air";

- a plurality of pipes, called “dry air supply tubes”, which are designed to supply dry air from the dehumidifier to predetermined locations, each of which is located on one of three devices, namely the first anchor mount, the second anchor mount and the multiple cable-stayed pipes;

- a ventilation device that pumps dry air into pipes from said plurality of dry air supply pipes; and

- means of inspection, measurement, management and testing.

The present invention will become better understood after reading the description below, given as an example, not limiting the scope of the invention, with reference to the attached drawings, of which:

figure 1 is a side view of the cable-stayed bridge;

figure 2 is a cross section of the upper part of the pylon of the cable-stayed bridge shown in figure 1, shown on an enlarged scale; and

figure 3 is a cross section of the lower part of the anchoring of the bridge canvas of the cable-stayed bridge shown in figure 1, shown on an enlarged scale.

The cable-stayed structure 1 is shown in the drawings. This cable-stayed structure 1 contains a plurality of tensile assemblies 8, each of which:

- consists of parallel steel elements 9 working in tension;

- passes between the first anchor mount 10 and the second anchor mount 11; and

- contains two opposite ends, a first end 100 and a second end 110, wherein said first end 100 interacts with a first anchor 10 and said second end 110 interacts with a second anchor 11.

To simplify the drawings, only one of said parallel tensile steel elements 9 is shown.

According to the present invention, the corrosion protection system 16 provides for the use of tensile elements 9, which during their manufacture do not provide permanent corrosion protection (for example, which are not coated with grease and sheath in the usual way) and which are called "unprotected tensile elements 9 "and this corrosion protection system 16 comprises:

- a lot of cable-stayed pipes 17, each of which freely surrounds the tensile assembly 8, which consists of unprotected tensile elements;

- a dehumidification device 19, which makes it possible to obtain a predetermined average level of air humidity, which is called “dry air 20”;

- a plurality of pipes, called “dry air supply pipes 21”, which are designed to supply dry air 20 from the drying device 19 to predetermined locations 22, each of which is located on one of three devices, namely, the first anchor mount 10, the second anchor mount 11 and a plurality of cable-stayed pipes 17;

- a ventilation device 23 that pumps dry air 20 into pipes from said plurality of dry air supply pipes 21;

- inspection, measurement, control and testing tools 24 to 27 (inspection tool 24, measuring tool 25, control tool 26 and testing tool 27).

In one of the options cable-stayed structure 1 contains:

- at least one first structural part 2; and

- at least one second structural part 5,

where said first structural part 2 and said second structural part 5 are connected by a plurality of tensile assemblies 8, each of which extends between a first anchor fastener 10 located on the first structural part 2 and a second anchor fastener 11 located on the second structural part 5, and

wherein at least one of said first structural part 2 and second structural part 5 comprises at least one inner chamber 4.

Note that each node 8, working in tension, contains elements 9, working in tension, which:

- are not connected together in the transverse direction so as to form a group; and

- along their length surrounded by air contained in the cable-stayed pipe 17.

Note that the cable-stayed pipe 17 can freely move in the transverse or longitudinal direction relative to the tensile assembly 8, which is covered by it.

According to the present invention:

- a plurality of pipes, called “dry air supply pipes 21”, is designed to supply dry air 20 from the drainage device 19 to predetermined locations 22, each of which is located close to one of the devices, namely the first anchor 10 and the second anchor 11 of each of the nodes 8 working in tension; and

- at least one of the nodes 8 operating in tension is connected to the first structural part 2 and the second structural part 5 for passing dry air into the inner chamber 4.

When said cable stay 1 is a cable-stayed bridge, this cable-stayed bridge contains:

- the first structural part 2 containing a bridge canvas; and

- at least a second structural part 5 included in the pylon, which has at least one actually vertical element containing the first part 6, which passes under the first structural part 2, and the second part 7, which passes over the first structural part 2.

For example, the first structural part 2 comprises a bridge web comprising a structural assembly 3 with at least one inner chamber 4.

Also, as an example, the structural unit 3 is made of metal, but can be made of metal or concrete, or any suitable material.

It is known that:

- each of the first anchor fasteners 10 contains a first block 12 of the anchor fastening, resting on the first bearing plate 13, which is supported by the first structural part 2; and

- each of the second anchor fasteners 11 contains a second block 14 of the anchor fastening, resting on the second carrier plate 15, which is supported by the second structural part 5.

In this case, a plurality of pipes, called “dry air supply pipes 21”, are intended to supply dry air 20 from the drying device 19 to predetermined locations 22, each of which is located adjacent to each of the second anchor fasteners 11 of the tensile assembly 8.

Preferably, the second anchor 11 and the first anchor 10 of each tensile assembly 8 are located in the housing, respectively called the “second anchor guide 29” and the “first anchor guide 30”.

Thus, tensile elements and their anchoring are enclosed in a housing along the entire length of the cable.

As an example, the drainage device 19 and the ventilation device 23 are located at the upper level 28 of the corresponding at least one second structural part 5.

We emphasize that:

- each guide 29 of the second anchor fastening is connected, on the one hand, to the dry air supply pipe 21, and on the other hand, to the cable-stayed pipe 17, in which the tensile unit 8 connected to it is enclosed, and these connections are made in such a way, so that the air introduced into the guide 29 of the second anchoring can create a stream of dry air 31 along the tensile assembly 8, which is located in the cable-stayed pipe 17; and

- each guide 30 of the first anchor fastener is connected to a cable stay 17, in which a tensile assembly 8 connected to it is enclosed, and this guide 30 of the first anchor fastener has a dry air outlet 32 through which dry air 20 can exit.

We emphasize that:

- the first dry air exhaust ducts 32 for the plurality of guides 30 of the first anchor fastener are connected to at least one inner chamber 4 so as to allow the passage of dry air 20 that exits from each of these first dry air exhaust ducts 32 said inner chamber 4; and

- the first structural part 2 contains at least one second channel 33 for the release of dry air through which dry air 20 can exit.

Preferably, dry air 20 may exit through the second dry air discharge channel 33 and is discharged into the atmosphere 34 surrounding the cable-stayed structure 1.

Thus, the tensile elements 9 and the anchoring of these elements 9 are temporarily protected from corrosion, that is, they are protected for storage or transportation.

As a result, the surfaces of each inner chamber 4 are exposed to dry air 20 and are therefore also protected against corrosion.

These technical features are particularly advantageous since, to protect the surfaces of the inner chambers of the cable-stayed structure, such as the inner chambers of the cable-stayed bridge bridge, no other corrosion protection system is required.

According to the present invention, the ventilation device 23, which injects dry air 20 into the dry air supply pipes 21, provides a predetermined and constant pressure value of said air along the length of each of the tensile nodes 8 in order to prevent the penetration of water molecules from the environment into the cable-stayed pipe 17 the guide 29 of the second anchor and the guide 30 of the first anchor for each tensile member.

In a preferred embodiment of the present invention:

- at least one of the guides 30 of the first anchoring is provided with a first sensor 36, a second sensor 37 and a third sensor 38, and these sensors 36 to 38 are intended for:

- measuring respectively the level of humidity, temperature and pressure of dry air 20 in each rail 30 of the first anchor fastening that is provided with them, and

- generating respectively a first signal 39, a second signal 40 and a third signal 41, which correspond to measured values of humidity, temperature and pressure;

- each of said first dry air exhaust channels 32 for a plurality of guides 30 of the first anchor fastener is provided with an air flow control valve called a “first air flow automatic control valve 42” that opens when the pressure of the air contained in the first anchor fastener guide 30, which equipped with this valve, rises above a predetermined value; and

- the control unit 43 creates the circulation of dry air 20 in the cable-stayed pipes 17 when, according to one of the signals, namely the first signal 39, the second signal 40 and the third signal 41, corresponding to the measured values of humidity, temperature and pressure, one of these parameters, namely humidity level, temperature or pressure, reaches a predetermined value.

The ventilation device 23 and the drainage device 19 are preferably operated by a control unit 43.

All these technical features make it possible to continuously monitor the condition of the corrosion protection system 16.

Moreover, we note that the continuous circulation of dry air 20 along the entire length of the tensile assembly 8 also equalizes any temperature difference in the said assembly 8.

In the preferred case, if the cable-stayed structure 1 contains a predetermined number of individual groups of 44 nodes 8 working in tension, then:

- the plurality of dry air supply pipes 21 form the number of groups of such pipes, which is equal to the aforementioned predetermined number of individual groups of 44 nodes 8 working in tension;

- each group of dry air supply pipes 21 is connected to the ventilation device by means of a main pipe containing a second air flow control valve 45; and

- each of said air flow control valves 45 is adjustable.

Tensile elements 9 may be coated.

For example, tensile members 9 are galvanized, epoxy coated or painted.

Note that the dehumidification device 19 makes it possible to obtain dry air 20 from moist air, which is taken from the atmosphere 34 surrounding the cable-stayed structure 1.

Also note that if the tensile assembly 8 includes a damping device 46, then this device is installed inside the housing forming the guide 30 of the first anchor fastening.

In the preferred case, each guide 30 of the first anchor fastener comprises a water discharge pipe 49 connected to a faucet (not shown) or closed by a drain plug (not shown).

The corrosion protection system 16 of the present invention allows continuous monitoring of the protection status.

The corrosion protection system 16 of the present invention provides three levels of protection, which are:

- a continuous layer of dry air 20 surrounding the tensile elements 9;

- coating elements 9 working in tension, leading to an increase in the originally planned short service life; and

- creating a shell along the entire cable, which is formed by a cable-stayed pipe 17, a guide 29 of the first anchor and a guide 30 of the second anchor.

Standard maintenance work on the corrosion protection system 16 basically involves replacing the filters in the drainage device 19.

The present invention also relates to cable-stayed structure 1 protected against corrosion by the system described above.

Claims (20)

1. Corrosion protection system (16) for cable-stayed construction (1) containing many tensile assemblies (8), each of which:
consists of parallel steel elements (9) working in tension;
passes between the first anchor mount (10) and the second anchor mount (11); and
contains two opposite ends, a first end (100) and a second end (110), said first end (100) interacting with a first anchor fastener (10), and said second end (110) interacting with a second anchor fastener (11), characterized the fact that it involves the use of elements (9) working in tension, which during their manufacture do not provide constant corrosion protection and which are called unprotected elements working in tension, and this system (16) of corrosion protection contains:
a lot of cable-stayed pipes (17), each of which freely surrounds the tensile unit (8), which consists of unprotected tensile elements;
a dehumidification device (19) allowing to obtain air with a predetermined average humidity level, which is called dry air (20);
a plurality of pipes, called dry air supply pipes (21), which is designed to supply dry air (20) from the drying device (19) to predetermined locations (22), each of these places is located on one of three devices, namely the first anchor a fastener (10), a second anchor fastener (11) and a plurality of cable-stayed pipes (17);
a ventilation device (23) that pumps dry air (20) into the pipes of said plurality of dry air supply pipes (21); and
tools (24) through (27) for inspection, measurement, control and testing. 2. The system according to claim 1, characterized in that the cable-stayed structure (1) contains:
at least one first structural part (2); and
at least one second structural part (5),
wherein said first structural part (2) and said second structural part (5) are connected by a plurality of tensile assemblies (8), each of which extends between a first anchor fastener (10) located on the first structural part (2) and the second anchor fastening (11) located on the second structural part (5), and
moreover, at least one of the aforementioned first structural part (2) and the second structural part (5) contains at least one inner chamber (4),
many pipes, called dry air supply pipes (21), are designed to supply dry air (20) from the drainage device (19) to predetermined locations (22), each of these places is located close to one of the devices, namely the first anchor (10) and a second anchorage (11) of each of the nodes (8) working in tension; and
at least one of the nodes (8) operating in tension is connected to the first structural part (2) and the second structural part (5) for passing dry air into the inner chamber (4). 3. The system according to claim 2, characterized in that the cable-stayed structure (1) is a cable-stayed bridge containing:
a first structural part (2) comprising a bridge web; and
at least one second structural part (5) that is part of the pylon, which has at least one actually vertical element containing the first part (6), which extends under the first structural part (2), and the second part ( 7), which passes over the first structural part (2). 4. The system according to claim 1, characterized in that the second anchor fastener (11) and the first anchor fastener (10) of each tensile assembly (8) are located in the housing, respectively called the guide (29) of the second anchor fastener and the guide (30) the first anchor. 5. The system according to claim 4, characterized in that:
each guide (29) of the second anchor fastening is connected, on the one hand, to the dry air supply pipe (21), and on the other hand, to the cable stay (17), which covers the tensile unit (8) connected to it, and these connections are made in such a way that the air introduced into the guide (29) of the second anchoring can create a stream (31) of dry air along the node (8) working in tension in the cable stay (17); and
each guide (30) of the first anchor fastener is connected to a cable-stayed pipe (17), which covers a tensile unit (8) connected to it, and this guide (30) of the first anchor fastener has a dry air discharge channel (32) through which dry air may escape (20). 6. The system according to claim 5, characterized in that:
the first dry air exhaust channels (32) of the plurality of guides (30) of the first anchoring are connected to at least one inner chamber (4) in such a way as to allow the passage of dry air (20) that exits from each of these first channels (32) discharging dry air into said inner chamber (4); and
the first structural part (2) comprises at least one exhaust channel, said second dry air discharge channel (33) through which dry air (20) can exit. 7. The system according to claim 4, characterized in that the ventilation device (23) forcing dry air (20) into the dry air supply pipes (21) provides a predetermined and constant value of the dry air pressure (20) along the length of each node (8) working in tension, to prevent the penetration of water molecules from the external environment into the cable-stayed pipe (17), the guide (29) of the second anchoring and the guide (30) of the first anchoring of each tensile element. 8. The system according to claim 5, characterized in that:
at least one of the guides (30) of the first anchor fastening is equipped with a first sensor (36), a second sensor (37) and a third sensor (38), and these sensors (36) to (38) are intended for:
measuring respectively the level of humidity, temperature and pressure of dry air (20) in each guide (30) of the first anchor fastening that is provided with them, and
generating a first signal (39), a second signal (40) and a third signal (41), respectively, which correspond to the measured values of humidity, temperature and pressure;
each of said first dry air exhaust channels (32) of said plurality of guides (30) of the first anchor fastener is provided with an air flow control valve called a first air flow control valve (42) that is capable of opening when air pressure is in the guide (30) the first anchor that is provided with this valve rises above a predetermined value; and
the control unit (43) creates the circulation of dry air (20) in the cable-stayed pipes (17) when, according to one of the signals, namely the first signal (39), the second signal (40) and the third signal (41) corresponding to the measured humidity values, temperature and pressure, one of these parameters, namely the level of humidity, temperature or pressure reaches a predetermined value. 9. The system according to claim 2, characterized in that if the cable-stayed structure (1) contains a predetermined number of individual groups (44) of nodes (8) working in tension, then:
a plurality of dry air supply pipes (21) form the number of groups of such pipes, which is equal to the aforementioned predetermined number of individual groups (44) of nodes (8) operating in tension;
each group of dry air supply pipes (21) is connected to the ventilation device by means of a main pipe containing a second air flow control valve (45); and
every second air flow control valve (45) is adjustable. 10. The system according to claim 2, characterized in that the drainage device (19) is configured to receive dry air (20) from moist air, which is taken from the atmosphere (34) surrounding the cable-stayed structure (1). 11. The system according to claim 2, characterized in that if the node (8) operating in tension contains a damping device (46), then this damping device (46) is installed inside the housing forming the guide (30) of the first anchor fastening. 12. The system according to claim 1, characterized in that each node (8), working in tension, contains elements (9), working in tension, which:
not connected together in the transverse direction so as to form a group; and
along the length are surrounded by air contained in the cable-stayed pipe (17). 13. The system according to claim 3, characterized in that the second anchor fastener (11) and the first anchor fastener (10) of each tensile assembly (8) are located in the housing, respectively called the guide (29) of the second anchor fastener and the guide (30) the first anchor. 14. The system according to item 13, characterized in that:
each guide (29) of the second anchor fastening is connected, on the one hand, to the dry air supply pipe (21), and on the other hand, to the cable stay (17), which covers the tensile unit (8) connected to it, and these connections are made in such a way that the air introduced into the guide (29) of the second anchoring can create a stream (31) of dry air along the node (8) working in tension in the cable stay (17); and
each guide (30) of the first anchor fastener is connected to a cable-stayed pipe (17), which covers a tensile unit (8) connected to it, and this guide (30) of the first anchor fastener has a dry air discharge channel (32) through which dry air may escape (20). 15. The system of claim 14, characterized in that:
the first dry air exhaust channels (32) of the plurality of guides (30) of the first anchoring are connected to at least one inner chamber (4) in such a way as to allow the passage of dry air (20) that exits from each of these first channels (32) discharging dry air into said inner chamber (4); and
the first structural part (2) comprises at least one exhaust channel, said second dry air discharge channel (33) through which dry air (20) can exit. 16. The system of claim 15, wherein the ventilation device (23) forcing dry air (20) into the dry air supply pipes (21) provides a predetermined and constant value of the dry air pressure (20) along the length of each node (8) working in tension, to prevent the penetration of water molecules from the external environment into the cable-stayed pipe (17), the guide (29) of the second anchoring and the guide (30) of the first anchoring of each tensile element. 17. The system according to clause 16, characterized in that:
at least one of the guides (30) of the first anchoring is provided with a first sensor (36), a second sensor (37) and a third sensor (38), and these sensors (36) to (38) are intended for:
measuring respectively the level of humidity, temperature and pressure of dry air (20) in each guide (30) of the first anchor fastening that is provided with them, and
generating respectively a first signal (39), a second signal (40) and a third signal (41), which correspond to the measured values of humidity, temperature and pressure;
each of said first dry air exhaust channels (32) of said plurality of guides (30) of the first anchor fastener is provided with an air flow control valve called a first air flow control valve (42) that is capable of opening when air pressure is in the guide (30) the first anchor that is provided with this valve rises above a predetermined value; and
the control unit (43) creates the circulation of dry air (20) in the cable-stayed pipes (17) when, according to one of the signals, namely the first signal (39), the second signal (40) and the third signal (41) corresponding to the measured humidity values, temperature and pressure, one of these parameters, namely the level of humidity, temperature or pressure reaches a predetermined value. 18. The system according to 17, characterized in that if the cable-stayed structure (1) contains a predetermined number of individual groups (44) of nodes (8) working in tension, then:
a plurality of dry air supply pipes (21) form the number of groups of such pipes, which is equal to the aforementioned predetermined number of individual groups (44) of nodes (8) operating in tension;
each group of dry air supply pipes (21) is connected to the ventilation device by means of a main pipe containing a second air flow control valve (45); and
every second air flow control valve (45) is adjustable. 19. The system of claim 8, characterized in that if the cable-stayed structure (1) contains a predetermined number of individual groups (44) of nodes (8) working in tension, then:
a plurality of dry air supply pipes (21) form the number of groups of such pipes, which is equal to the aforementioned predetermined number of individual groups (44) of nodes (8) operating in tension;
each group of dry air supply pipes (21) is connected to the ventilation device by means of a main pipe containing a second air flow control valve (45); and
every second air flow control valve (45) is adjustable. 20. Cable-stayed structure (1) containing a corrosion protection system (16) according to claim 1.
The priority was established on November 12, 2004 by the filing date of the international application PCT / EP2004 / 052952.

Images