WO2021208539A1 - Bridge cable corrosion all-weather on-line monitoring system and method - Google Patents

Abstract

Disclosed are a bridge cable corrosion all-weather on-line monitoring system and method. The monitoring system comprises an integrated communication box and a monitoring integrated box, wherein the monitoring integrated box is attached to the position of a cable without a protective coating, and wherein the integrated communication box is electrically connected with the monitoring integrated box to perform signal data acquisition. The present invention can perform all-weather, on-line and real-time monitoring on the corrosion rate state of a bridge cable, achieving on-line acquisition of corrosion data in the service process of the bridge cable.

Description

All-weather online monitoring system and method for bridge cable corrosion Technical field

The invention belongs to the technical field of bridge corrosion protection, and more specifically relates to an all-weather online monitoring system and method for bridge cable corrosion.

Background technique

Cables (main cables, slings, stay cables) are the main stress-bearing components of suspension bridges/cable-stayed bridges, which bear all the loads of the bridge and are not easy to replace during the entire service life of the bridge. Under the atmospheric corrosive environment and load, as time goes by, the cable steel wire and its protective layer will inevitably produce corrosion and damage, shorten the service life of the bridge, and make it difficult to evaluate the safety and reliability of the bridge. Therefore, in order to ensure the structural safety of the bridge and prevent the occurrence of operational accidents, it is necessary to conduct on-line corrosion monitoring of the bridge cables to ensure the safety of the bridge throughout its life.

The early detection of bridge cables was mainly based on manual observation. High-altitude operations seriously threatened the lives of technicians and were subject to greater subjective influence. In addition, the magnetic leakage detection method is not perfect in theory, and there are difficulties in quantitative detection. When there are original defects on the surface of the steel wire inside the cable, there are also large errors based on the ultrasonic detection method. Both of the above-mentioned detection schemes require manual high-altitude operations, and are periodic maintenance inspections for bridge operation, which makes it difficult to realize all-weather online monitoring.

Therefore, how to provide an all-weather online monitoring system and method for bridge cable corrosion is an urgent problem to be solved by those skilled in the art.

Summary of the invention

In view of this, the present invention provides a bridge cable corrosion all-weather online monitoring system and method, which can monitor the bridge cable corrosion rate status online in real time all-weather, and realize online collection of corrosion data of the bridge cable during service.

In order to achieve the above objectives, the present invention adopts the following technical solutions:

A bridge cable corrosion all-weather online monitoring system, comprising: an integrated communication box and a monitoring integrated box, the monitoring integrated box is attached to the non-protective coating of the cable, and the integrated communication box is electrically connected to the monitoring integrated box. Sexual connection for signal data collection.

Preferably, the monitoring integrated box is arranged in an air clamp, an airtight waterproof head is installed on the air clamp, and a wire connecting the integrated communication box and the monitoring integrated box passes through the airtight and waterproof head.

Preferably, the air clamp is arranged at the position of the cable inlet point and the cable outlet point.

Preferably, the integrated communication box integrates a lightning arrester, an air switch, a power carrier communication module, a switching power supply, a resistance corrosion monitor, and a temperature and humidity monitor.

Preferably, the monitoring integrated box is provided with a temperature and humidity sensor, a corrosion metal wire and a reference metal wire, the temperature and humidity sensor and the corrosion metal wire are both exposed outside the monitoring integrated box, and the reference metal wire It is embedded in the monitoring integrated box.

Preferably, the temperature and humidity monitor is used to collect the signal of the temperature and humidity sensor, and the resistance corrosion monitor is used to collect the signal of the corrosion metal wire and the reference metal wire, and transmit the adopted signal through the power carrier communication module To the bridge management center.

A method for all-weather online monitoring of bridge cable corrosion. A monitoring integrated box is attached to the unprotected coating of the cable, an integrated communication box is arranged on the handrail rope of the cable, and the integrated communication box is integrated with the monitoring The boxes are electrically connected to collect signal data, realize all-weather online monitoring of beam cable corrosion, and set up multiple corrosion monitoring points for all-round monitoring.

_{Preferably, the resistance value R x of the corrosion metal wire leaking from the monitoring integrated box and the resistance value R f} of the reference metal wire embedded in the monitoring integrated box are detected by the resistance corrosion monitor in the integrated communication box. The temperature and humidity monitor in the communication box collects the signal of the temperature and humidity sensor leaked from the monitoring integrated box.

Preferably, the ratio λ(t) of the resistance value R _{x of the} corrosion metal wire to the resistance value R _{f of the reference metal wire satisfies:}

Among them, L _x is the length of the corroded wire, L _f is the length of the reference wire; r _x (t) is the radius of the corroded wire, r _f is the radius of the reference wire; t is the time of measurement;

Derived from formula (1):

The corrosion rate V _{x of the} corroded metal wire is derived from the formula (2):

The beneficial effects of the present invention are:

(1) The outdoor integrated communication box of the present invention integrates a lightning arrester, an air switch, a power carrier communication module, a switching power supply, a resistance corrosion monitor, and a temperature and humidity monitor, which is convenient for rapid installation at high altitude and can monitor the cable corrosion rate online in real time all-weather Status, realizing online collection of corrosion data during cable service.

(2) The monitoring integrated box used in the bridge cable of the present invention is small in size and can be flexibly installed in the air clamp. The cable is arranged in a circumferential direction to facilitate the horizontal comparison of the measurement points. It uses multiple cable inlet and exhaust ports in the longitudinal direction. Comparison of test points enables comprehensive and omni-directional monitoring of cable corrosion status.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without creative work.

Figure 1 is a schematic diagram of the structure of the present invention.

Figure 2 is a schematic diagram of the installation structure of the monitoring integrated box of the present invention.

Figure 3 is a schematic diagram of the structure of the monitoring integrated box of the present invention.

Figure 4 is a construction drawing of the monitoring integrated box of the present invention.

Fig. 5 is a schematic diagram of the arrangement structure of the monitoring points of the present invention.

Fig. 6 is a graph showing the change curve of the resistance ratio of each corrosion monitoring point of the present invention.

Fig. 7 is a graph showing the corrosion rate change curve of each corrosion monitoring point of the present invention.

Among them, in the figure,

1- cable inlet point; 2- cable exhaust point; 3- corrosion monitoring point; 4- cable; 5- bridge deck; 6-upstream main cable; 7-downstream main cable; 8-220V power line; 9-one Chemical communication box; 10-dry air inlet; 11-air clamp; 12-monitoring integrated box; 13-airtight waterproof head; 14-protective coating; 15-corrosion metal wire; 16-reference metal wire; 17-temperature and humidity sensor.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Please refer to Figures 1-5, the present invention provides a bridge cable corrosion all-weather online monitoring system. The cables 4 are connected on both sides of the bridge deck 5 and include: an integrated communication box 9 and a monitoring integrated box 12, integrated communication The box 9 is arranged on the cable handrail rope, and the power is supplied through the 220V power line 8. The monitoring integrated box 12 is attached to the unprotected coating 14 of the cable, and it is closely attached to the cable circumferential direction through a cable tie or fixing glue, and integrated communication The box 9 is electrically connected to the monitoring integrated box 12 for signal data collection.

In another embodiment, the monitoring integrated box 12 is arranged in the air clip 11, the air clip 11 is arranged at the cable inlet point 1 and the cable outlet point 2, and the air clip 11 is provided with a dry air inlet 10 to ensure The air in the air clip 11 circulates. An airtight waterproof head 13 is installed on the air clamp 11, and the wire connecting the integrated communication box 9 and the monitoring integrated box 12 passes through the airtight waterproof head 13, which ensures the sealing of the monitoring system and improves the waterproof performance.

The integrated communication box 9 integrates lightning arrester, air switch, power carrier communication module, switching power supply, resistance corrosion monitor, temperature and humidity monitor, which is convenient for rapid installation at high altitude. The monitoring integrated box 12 is provided with a temperature and humidity sensor 17, a corrosion metal wire 15 and a reference metal wire 16. The wire 16 is embedded in the monitoring integrated box 12, and is not in contact with the external environment, and can be better compared with the corrosion resistance of the corroded metal wire 15 in the case of corrosion. The thickness of the monitoring integrated box 12 can be 0.5～1mm. The corrosion wire 15, the reference wire 16, and the temperature and humidity sensor 17 are integrated together. The size is small and can be flexibly installed at the cable inlet point 1, the cable outlet point 2. Clip 11 inside.

The temperature and humidity monitor is used to collect the signals of the temperature and humidity sensor 17, and the resistance corrosion monitor is used to collect the signals of the corrosion wire 15 and the reference wire 16, and transmit the adopted signals to the bridge management center through the power carrier communication module.

A method for all-weather online monitoring of bridge cable corrosion. The monitoring integrated box 12 is attached to the unprotected coating 14 of the cable 4, the integrated communication box 9 is arranged on the handrail of the cable, and the integrated communication box 9 is connected to the monitoring The integrated box 12 is electrically connected for signal data collection to realize all-weather online monitoring of beam cable corrosion. Multiple corrosion monitoring points 3 are set for comprehensive monitoring. Corrosion monitoring is provided on the upstream main cable 6 and downstream main cable 7 of the cable. Point 3.

The present invention uses the resistance corrosion monitor in the integrated communication box 9 to detect the resistance value R _{x of the corrosion metal wire 15 leaking in the monitoring integrated box 12 and the resistance value R f} of the reference metal wire 16 embedded in the monitoring integrated box 12 , Through the temperature and humidity monitor in the integrated communication box 9 to collect the signal leaked from the temperature and humidity sensor 17 of the monitoring integrated box 12.

Among them, the ratio λ(t) of the resistance value R _{x of the} corrosion metal wire 15 to the resistance value R _{f of the reference metal wire 16 satisfies:}

Among them, L _x is the length of the corrosion wire 15 and L _f is the length of the reference wire 16; r _x (t) is the radius of the corrosion wire 15 and r _f is the radius of the reference wire 16; t is the measurement time Time; the radius r _x (t) of the corrosion wire 15 will gradually decrease as the corrosion progresses, the reference wire 16 is in the enclosed probe body, and its radius r _f remains unchanged.

Derived from formula (1):

_{The corrosion rate V x} of the corroded wire 15 is derived from the formula (2):

The outdoor integrated communication box 9 of the present invention integrates a lightning arrester, an air switch, a power carrier communication module, a switching power supply, a resistance corrosion monitor, and a temperature and humidity monitor, which is convenient for high-altitude and fast installation, and can monitor the cable corrosion rate status online in real time all-weather. Realize the online collection of corrosion data during the service of the cable.

The monitoring integrated box 12 used in the bridge cable of the present invention has a small size and can be flexibly installed in the air clamp 11. The cable circumferentially fitted arrangement is used to facilitate the horizontal comparison of the measurement points, and the multiple cable inlet and exhaust ports are used for longitudinal testing. Point comparison to achieve comprehensive and all-round monitoring of cable corrosion status.

Referring to Figures 6-7, the present invention is applied to the real bridge monitoring results of a cross-sea bridge. During the construction period of the cross-sea bridge, a large amount of water remains in the cables. After the construction is completed and enters the maintenance period, the cable dehumidification system is operated. After dry air is passed to the inside of the cable, the relative humidity in the cable decreases within a period of time (0.5-1 year). A certain range, and remain below 50% for a long period of time. Therefore, the test results of the present invention can be seen: the instantaneous corrosion rate of corrosion wire 15 (5:57 on December 23, 2019): SS3, 14.66μm/a, corrosion to 5:57 on December 31, 2019 The average rate is 5.727 μm/a. The corrosion rate trend showed a logarithmic function (y=-53734ln(x)+574088), and gradually slowed down with time.

The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown in this document, but should conform to the widest scope consistent with the principles and novel features disclosed in this document.

Claims (9)

1. An all-weather online monitoring system for bridge cable corrosion, which is characterized by comprising: an integrated communication box and a monitoring integrated box, the monitoring integrated box is attached to the non-protective coating of the cable, and the integrated communication box is Monitor the electrical connection of the integrated box for signal data collection.
2. The all-weather online monitoring system for bridge cable corrosion according to claim 1, wherein the monitoring integrated box is arranged in an air clamp, an airtight waterproof head is installed on the air clamp, and the integrated The wire connecting the communication box and the monitoring integrated box passes through the airtight waterproof head.
3. The all-weather online monitoring system for bridge cable corrosion according to claim 2, wherein the air clamp is arranged at the position of the cable inlet point and the cable outlet point.
4. The all-weather online monitoring system for bridge cable corrosion according to claim 1 or 3, wherein the integrated communication box integrates a lightning arrester, an air switch, a power carrier communication module, a switching power supply, a resistance corrosion monitor, temperature and humidity Monitor in one.
5. The all-weather online monitoring system for bridge cable corrosion according to claim 4, wherein the monitoring integrated box is provided with a temperature and humidity sensor, a corrosion wire and a reference wire, the temperature and humidity sensor and the corrosion The metal wires are exposed on the outside of the monitoring integrated box, and the reference metal wires are embedded in the monitoring integrated box.
6. The all-weather online monitoring system for bridge cable corrosion according to claim 5, wherein the temperature and humidity monitor is used to collect signals from the temperature and humidity sensor, and the resistance corrosion monitor is used to collect corroded metal wires. And reference the signal of the metal wire, and transmit the adopted signal to the bridge management center through the power carrier communication module.
7. The method for all-weather online monitoring of bridge cable corrosion according to claim 6, characterized in that the monitoring integrated box is attached to the unprotected coating of the cable, the integrated communication box is arranged on the handrail rope of the cable, and The integrated communication box is electrically connected with the monitoring integrated box to perform signal data collection to realize all-weather online monitoring of beam cable corrosion, and set up multiple corrosion monitoring points for comprehensive monitoring.
8. The method for all-weather online monitoring of bridge cable corrosion according to claim 7, characterized in that the resistance value R _x of the corrosion metal wire leaking from the monitoring integrated box and the resistance value R x and the internal _{The resistance value R f} of the reference metal wire embedded in the monitoring integrated box is collected by the temperature and humidity monitor in the integrated communication box to collect the signal leaking from the temperature and humidity sensor of the monitoring integrated box.
9. The method for all-weather online monitoring of bridge cable corrosion according to claim 8, wherein the ratio λ(t) _{of the resistance value R x of the} corrosion metal wire to the resistance value R _{f of the reference metal wire satisfies:}

   

   Among them, L _x is the length of the corroded wire, L _f is the length of the reference wire; r _x (t) is the radius of the corroded wire, r _f is the radius of the reference wire; t is the time of measurement;

   Derived from formula (1):

   

   The corrosion rate V _{x of the} corroded metal wire is derived from the formula (2):

   

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