Bridge cable damage diagnosis method and device based on multi-risk source identification

Abstract

The present invention discloses a bridge cable damage diagnosis method and device based on multi-risk source identification, which collects on-site information of the bridge cable after the actual bridge sends an emergency event, determines the risk source identification code according to the on-site information, inputs the risk source identification code into a pre-constructed damage assessment model, and outputs the damage level and damage status evaluation of the bridge cable. The risk source identification coding of the present invention realizes the comprehensive identification of risk source events that cause potential cable damage, and forms a comprehensive coding method for information composition, which can quickly integrate on-site information after the event occurs to guide emergency response; the damage classification of each coding result is formed in advance, and when the event occurs, it can quickly guide the emergency response based on the coding science, improve the efficiency of emergency response, avoid insufficient response or risk diffusion, and avoid waste of resources caused by excessive response.

Description

Technical Field

[0001] The invention relates to a bridge suspension cable damage diagnosis method and device based on multi-risk source identification, belonging to the technical field of bridge monitoring. Background Art

[0002] Large-span cable-supported bridges are one of the main forms of cross-river and cross-sea bridges. Such bridges generally have the characteristics of large construction investment, long design cycle, large traffic volume, and complex operating conditions. Among them, the cable-stayed bridge and suspension bridge are the main load-bearing structures. Once the structure is damaged due to an emergency, it will not only affect the normal operation of traffic, but may even cause the collapse of the bridge, seriously endangering the safety of people's lives and property, and causing huge economic losses and social impacts. There are currently few targeted response theories and methods for emergency disposal of cable damage during bridge operation. Some management units will prepare emergency response plans for emergencies, but they are mainly aimed at bridge deck traffic diversion, control, accident site handling, etc. after the cable damage. For the disposal of the damaged structure itself, the usual practice is that after the emergency occurs, a professional bridge consulting unit will investigate the on-site situation, and then carry out structural analysis, calculation and evaluation work based on the investigation results to determine the safety of the bridge structure and subsequent disposal measures.

[0003] This type of disposal method has the following shortcomings: First, the disposal process goes through multiple steps such as on-site investigation, structural modeling, simulation analysis, and plan formulation, which is time-consuming. During this period, the safety status of the bridge structure cannot be clarified, and there is a lack of scientific basis for the traffic control plan, which delays the precious emergency disposal time and causes great economic losses; Second, the risks that may cause damage to the slings are diverse, and the degree of damage caused is also different. Therefore, the corresponding disposal plan is also highly targeted. Past disposal experience is difficult to use to deal with other risks that may be faced in the future, it is difficult to improve emergency efficiency, and it causes waste of resources. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a bridge cable damage diagnosis method and device based on multi-risk source identification. By comprehensively identifying various risk sources that may cause bridge cable damage and the emergencies that may be caused, and performing graded assessments according to their types and degree of damage, the corresponding disposal work can be carried out immediately at the first time when the sudden incident of cable damage occurs, so as to improve the efficiency of emergency disposal, reduce the impact of emergencies, and reduce the cost of emergency work.

[0005] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions.

[0006] On the one hand, the present invention discloses a bridge cable damage diagnosis method based on multi-risk source identification, comprising:

[0007] Collecting on-site information of the bridge cable after the real bridge sends an emergency event, determining the risk source identification code according to the on-site information, inputting the risk source identification code into a pre-built damage assessment model, and outputting the damage level and damage condition assessment of the bridge cable;

[0008] The construction of the damage assessment model includes:

[0009] Count the potential risk sources of bridges, encode the potential risk sources of bridges, and obtain the risk source identification code;

[0010] Analyze the degree of damage caused by the risk source to the sling structure under each risk source identification code, and classify the damage from shallow to deep according to the degree of damage;

[0011] The classified different damages are substituted into the damage calculation model pre-constructed based on the corresponding bridge structure to obtain the overall state of the bridge structure. The safety state of the overall state of the bridge structure under different damage degrees of the components is judged according to the principle of the bridge allowable stress method. The bridge safety risk level is set based on the safety state under different damage degrees, and the relationship between component damage degree and bridge safety risk level is established to form a damage evaluation model.

[0012] Further, determining the risk source identification code according to the on-site information includes:

[0013] Obtain the risk source type, risk source, span where the cable is located, upstream and downstream sides, cable function division and number from the on-site information of the bridge cable;

[0014] According to the preset coding sequence and coding symbols, the risk source type, risk source, span where the pull rope is located, upstream and downstream sides, pull rope functional division and number are encoded in turn to obtain the risk source identification code.

[0015] Furthermore, it also includes: setting response levels based on different bridge safety risk levels, response measures and control methods corresponding to the response levels.

[0016] Furthermore, the statistical analysis of the potential risk sources of bridges and encoding the potential risk sources of bridges to obtain risk source identification codes includes:

[0017] The risk source type, risk source, span where the pull rope is located, upstream and downstream sides, functional divisions and numbers are coded in sequence to form a risk source identification code;

[0018] The risk source type is a first code, which is encoded according to fire risk, impact risk, natural and meteorological disaster risk, hazardous chemical risk, and structure / component disease risk;

[0019] The risk source is the second code, which is coded based on illegal stacking of combustible / flammable / explosive materials, spontaneous combustion of ordinary passenger / truck vehicles, spontaneous combustion / leakage of hazardous chemicals vehicles, spontaneous combustion of cargo ships, arson, burning of wires / electrical short circuits, and excessive fire during construction operations;

[0020] The span where the pull rope is located is a third code and a fourth code, the third code is encoded according to the type of the main span / side span, and the fourth code is encoded according to the span number of the main span / side span;

[0021] The upstream and downstream sides are fifth codes, and the fifth codes are encoded according to the cable surface position of the cable-stayed bridge;

[0022] The functional divisions and numbers are the sixth code and the seventh code. The sixth code is encoded according to the contrasting features of the pull rope, and the seventh code is encoded according to the specific number of the pull rope.

[0023] Furthermore, the setting of the bridge safety risk level based on the safety status under different damage degrees includes:

[0024] Analyze the damage degree of the sling to determine the damage category, which includes: non-broken wire damage, broken wire damage and fracture damage;

[0025] The degree of damage is graded based on the damage category, and the degree of damage is graded from severe to mild, including level one damage, level two damage, level three damage, and level four damage; the non-broken wire damage belongs to level three damage or level four damage; the broken wire damage belongs to level three damage or level four damage; the fracture damage belongs to level one damage or level two damage.

[0026] Furthermore, judging the damage level of the non-broken wire damage includes:

[0027] Collect the fire time, temperature and PE sheath condition of the sling;

[0028] When the fire time is not less than the first time threshold and the temperature is not less than the first temperature threshold, the damage level of the non-broken wire damage is determined to be level three damage;

[0029] When the fire time is lower than the first time threshold and the temperature is lower than the first temperature threshold, the damage level of the non-broken wire damage is determined to be level 4 damage;

[0030] When the fire time is not less than the second time threshold and the temperature is less than the second temperature threshold, the damage level of the non-broken wire damage is determined to be level 4 damage, wherein the second time threshold is greater than the first time threshold, and the second temperature threshold is less than the first temperature threshold;

[0031] The PE sheath of the sling was damaged but the steel wire of the sling was not damaged. The damage level of non-broken wire damage was determined to be level four.

[0032] Furthermore, determining the damage level of the broken wire damage includes:

[0033] The effective cross-sectional area of ​​the remaining steel wire in the sling after collecting the broken wire ;

[0034] Obtain the standard value of the tensile strength of the steel wire of the sling , Design value of axial tension of the cable ;

[0035] The safety factor of the rope body of the rope after the wire is broken is calculated by the following formula: K ,

[0036] ;

[0037] When the safety factor of the cable body is calculated K Not greater than the first safety factor threshold K 1, the damage level of broken wire damage is determined to be level 3 damage;

[0038] When the safety factor of the cable body is calculated K Greater than the first safety factor threshold K 1 and not greater than the second safety factor threshold K 2, the damage level of broken wire damage is determined to be level 4 damage, among which the second safety factor threshold K 2 is greater than the first safety factor threshold K 1.

[0039] Further, determining the damage level of the fracture damage includes:

[0040] When a single sling breaks, determine the force increment of other cables ;

[0041] Obtain the standard value of the tensile strength of the steel wire of the sling , Design value of axial tension of the cable , the effective cross-sectional area of ​​pure steel wire in the cable body of the sling ;

[0042] The safety factor of other cables is calculated using the following formula: K ,

[0043] ;

[0044] When calculating the cable body safety factor of other cables K Greater than the first safety factor threshold K 1 and not greater than the second safety factor thresholdK 2, the damage level of the fracture damage is determined to be secondary damage, where the second safety factor threshold K 2 is greater than the first safety factor threshold K 1;

[0045] When calculating the cable body safety factor of other cables K Not greater than the first safety factor threshold K 1, the damage level of the broken wire damage is determined to be level one damage.

[0046] Furthermore, the determination of the cable force increment of other cable bodies ,include:

[0047] Obtain design information of the target bridge;

[0048] Establish the finite element model of the whole bridge based on the design data;

[0049] By removing the corresponding cable body in the finite element model of the whole bridge, the cable fracture condition is simulated and the cable force increment of other cables after fracture relative to before fracture is obtained.

[0050] In a second aspect, the present invention discloses a bridge cable damage diagnosis device based on multi-risk source identification, comprising:

[0051] The collection module is used to collect the on-site information of the bridge cable after the real bridge sends an emergency;

[0052] A determination module, used to determine a risk source identification code according to the on-site information;

[0053] The diagnosis module is used to input the risk source identification code into the pre-built damage assessment model and output the damage level and damage condition assessment of the bridge suspension cable;

[0054] The construction of the damage assessment model includes:

[0055] Count the potential risk sources of bridges, encode the potential risk sources of bridges, and obtain the risk source identification code;

[0056] Analyze the degree of damage caused by the risk source to the sling structure under each risk source identification code, and classify the damage from shallow to deep according to the degree of damage;

[0057] The classified different damages are substituted into the damage calculation model pre-constructed based on the corresponding bridge structure to obtain the overall state of the bridge structure. The safety state of the overall state of the bridge structure under different damage degrees of the components is judged according to the principle of the bridge allowable stress method. The bridge safety risk level is set based on the safety state under different damage degrees, and the relationship between component damage degree and bridge safety risk level is established to form a damage evaluation model.

[0058] The beneficial effects achieved by the present invention are:

[0059] The risk source identification coding described in the present invention realizes the comprehensive identification of risk source events that cause potential damage to the sling, and forms a comprehensive coding method for information composition, which can quickly integrate on-site information after the event occurs to guide emergency response. The sling damage evaluation method forms the damage classification of each coding result in advance through pre-work and classification evaluation. When the event occurs, it can quickly guide the emergency response based on the coding science, improve the efficiency of emergency response, avoid insufficient response or risk diffusion, and avoid waste of resources caused by excessive response. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 It is a schematic diagram of the process of the present invention;

[0061] Figure 2 It is a schematic diagram of the risk source identification coding of the present invention. DETAILED DESCRIPTION

[0062] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0063] Example 1: In the current emergency response process of cable-type bridges, it is often impossible to quickly judge the structural status according to the on-site incident and the appearance of the cable structure damage, formulate and initiate reasonable emergency response measures, resulting in over-response or under-response, resulting in waste of resources or greater economic losses. To this end, this example introduces a bridge cable damage diagnosis method based on multi-risk source identification, including:

[0064] Collecting on-site information of the bridge cable after the real bridge sends an emergency event, determining the risk source identification code according to the on-site information, inputting the risk source identification code into a pre-built damage assessment model, and outputting the damage level and damage condition assessment of the bridge cable;

[0065] The construction of the damage assessment model includes:

[0066] Count the potential risk sources of bridges, encode the potential risk sources of bridges, and obtain the risk source identification code;

[0067] Analyze the degree of damage caused by the risk source to the sling structure under each risk source identification code, and classify the damage from shallow to deep according to the degree of damage;

[0068] The classified different damages are substituted into the damage calculation model pre-constructed based on the corresponding bridge structure to obtain the overall state of the bridge structure. The safety state of the overall state of the bridge structure under different damage degrees of the components is judged according to the principle of the bridge allowable stress method. The bridge safety risk level is set based on the safety state under different damage degrees, and the relationship between component damage degree and bridge safety risk level is established to form a damage evaluation model.

[0069] According to the risk source classification, the structural damage is discussed (the structure here refers to the overall structure of the bridge, that is, the risk source causes damage to one or several cable stays in the structure, which leads to the impact on the overall safety risk of the structure). First, a finite element or other calculation model of the structure is established, and then the possible damage to the cable stays is classified from shallow to deep according to the characteristics of different risks, and the classified cable stays damage is substituted into the calculation model one by one. Finally, according to the principle of the allowable stress method of the bridge, the overall stress calculation of the structure under different damage degrees is used to evaluate whether the damaged structure can meet the safe operation requirements of the bridge. Based on this, the damage level and damage evaluation results are formed, and the response level, corresponding emergency response measures and control methods are further formed.

[0070] For example, for fire damage risks, based on the bridge risk source information and coding compiled in advance, for any risk source, the possible damage to the pull cables is classified and discussed. For each damage situation, it is substituted into the structural calculation model to calculate the safety risk to the overall structure of the bridge. It is divided into different levels based on whether it meets the requirements for safe bridge operation, thus forming a damage assessment semantic model.

[0071] When a fire damage event occurs on site, the main risk situation on site can be immediately transmitted back according to the risk source code, and then the on-site information can be further collected. For example, if the fire damage is caused by vehicle collision and combustion, the vehicle model information and combustion time can be collected, and the fire temperature of the sling can be inferred according to the vehicle type, and the fire time of the sling can be determined according to the combustion time. Then check the state of the cable body after damage, whether the PE sheath is completely melted to expose the steel wire, or only the outer layer is burned black. Based on the above information, combined with the damage assessment semantic model, the safety status level of the structure can be directly given, and then the corresponding emergency response and emergency disposal can be carried out.

[0072] The step of determining the risk source identification code according to the on-site information includes:

[0073] Obtain the risk source type, risk source, span where the cable is located, upstream and downstream sides, cable function division and number from the on-site information of the bridge cable;

[0074] According to the preset coding sequence and coding symbols, the risk source type, risk source, span where the pull rope is located, upstream and downstream sides, pull rope functional division and number are encoded in turn to obtain the risk source identification code.

[0075] It also includes: setting response levels based on different bridge safety risk levels, response measures and management methods corresponding to the response levels.

[0076] The counting of potential risk sources of bridges and encoding of potential risk sources of bridges to obtain risk source identification codes include:

[0077] The risk source type, risk source, span where the pull rope is located, upstream and downstream sides, functional divisions and numbers are coded in sequence to form a risk source identification code;

[0078] The risk source type is a first code, which is encoded according to fire risk, impact risk, natural and meteorological disaster risk, hazardous chemical risk, and structure / component disease risk;

[0079] The risk source is the second code, which is coded based on illegal stacking of combustible / flammable / explosive materials, spontaneous combustion of ordinary passenger / truck vehicles, spontaneous combustion / leakage of hazardous chemicals vehicles, spontaneous combustion of cargo ships, arson, burning of wires / electrical short circuits, and excessive fire during construction operations;

[0080] The span where the pull rope is located is a third code and a fourth code, the third code is encoded according to the type of the main span / side span, and the fourth code is encoded according to the span number of the main span / side span;

[0081] The upstream and downstream sides are fifth codes, and the fifth codes are encoded according to the cable surface position of the cable-stayed bridge;

[0082] The functional divisions and numbers are the sixth code and the seventh code. The sixth code is encoded according to the contrasting features of the pull rope, and the seventh code is encoded according to the specific number of the pull rope.

[0083] The setting of the bridge safety risk level based on the safety status under different damage degrees includes:

[0084] Analyze the damage degree of the sling to determine the damage category, which includes: non-broken wire damage, broken wire damage and fracture damage;

[0085] The degree of damage is graded based on the damage category, and the degree of damage is graded from severe to mild, including level one damage, level two damage, level three damage, and level four damage; the non-broken wire damage belongs to level three damage or level four damage; the broken wire damage belongs to level three damage or level four damage; the fracture damage belongs to level one damage or level two damage.

[0086] Determining the damage level of the non-broken wire damage includes:

[0087] Collect the fire time, temperature and PE sheath condition of the sling;

[0088] When the fire time is not less than the first time threshold and the temperature is not less than the first temperature threshold, the damage level of the non-broken wire damage is determined to be level three damage;

[0089] When the fire time is lower than the first time threshold and the temperature is lower than the first temperature threshold, the damage level of the non-broken wire damage is determined to be level 4 damage;

[0090] When the fire time is not less than the second time threshold and the temperature is less than the second temperature threshold, the damage level of the non-broken wire damage is determined to be level 4 damage, wherein the second time threshold is greater than the first time threshold, and the second temperature threshold is less than the first temperature threshold;

[0091] The PE sheath of the sling was damaged but the steel wire of the sling was not damaged. The damage level of non-broken wire damage was determined to be level four.

[0092] Determining the damage level of the broken wire damage includes:

[0093] The effective cross-sectional area of ​​the remaining steel wire in the sling after collecting the broken wire ;

[0094] Obtain the standard value of the tensile strength of the steel wire of the sling , Design value of axial tension of the cable ;

[0095] The safety factor of the rope body of the rope after the wire is broken is calculated by the following formula: K ,

[0096] ;

[0097] When the safety factor of the cable body is calculated K Not greater than the first safety factor threshold K 1, the damage level of broken wire damage is determined to be level 3 damage;

[0098] When the safety factor of the cable body is calculated K Greater than the first safety factor threshold K 1 and not greater than the second safety factor threshold K 2, the damage level of broken wire damage is determined to be level 4 damage, among which the second safety factor threshold K 2 is greater than the first safety factor threshold K 1.

[0099] Determining the damage level of the fracture damage includes:

[0100] When a single sling breaks, determine the force increment of other cables ;

[0101] Obtain the standard value of the tensile strength of the steel wire of the sling , Design value of axial tension of the cable , the effective cross-sectional area of ​​pure steel wire in the cable body of the sling ;

[0102] The safety factor of other cables is calculated using the following formula: K ,

[0103] ;

[0104] When calculating the cable body safety factor of other cables K Greater than the first safety factor threshold K 1 and not greater than the second safety factor threshold K 2, the damage level of the fracture damage is determined to be secondary damage, where the second safety factor threshold K 2 is greater than the first safety factor threshold K 1;

[0105] When calculating the cable body safety factor of other cables K Not greater than the first safety factor threshold K 1, the damage level of the broken wire damage is determined to be level one damage.

[0106] Determining the cable force increment of other cable bodies ,include:

[0107] Establish the finite element model of the whole bridge based on the design data;

[0108] By removing the corresponding cable body in the model, the cable fracture condition is simulated and the increments of other cable bodies before and after fracture are obtained.

[0109] According to the risk sources occurring on site, obtain the risk source identification code by comparing it with the preset risk source identification manual;

[0110] According to the risk source identification code and the damage degree of the tension cable components, the corresponding working conditions in the damage assessment model are found to obtain the corresponding damage level, that is, the bridge safety risk level, that is, the damage status evaluation.

[0111] Example 2. This example specifically introduces a bridge cable damage diagnosis method based on multi-risk source identification, including risk source identification coding and cable damage classification and quantitative evaluation. First, the risk sources and risk damage patterns that the cable components of the cable system bridge may suffer are comprehensively screened, counted and summarized, and the risk source categories and potential component damage patterns are coded into a book according to unified rules; secondly, according to the type and degree of cable damage, a rapid damage evaluation method for damaged component objects and the entire structure is proposed; finally, when an incident occurs, according to the on-site observation results or the existing health monitoring system data response analysis results, the risk source code string is determined and the damage status is evaluated, and emergency response is initiated.

[0112] (1) Risk source identification code:

[0113] In order to fully count and express the potential risk patterns of the cable-stayed cable structure of the cable-stayed bridge, the risk source identification code is divided into the following parts: risk source type, risk source, span where the cable is located, upstream and downstream, functional division and number. Figure 2 As shown:

[0114] Risk source type: The first coded position is the risk source type that causes damage to the sling. According to statistics, there are five major categories, namely: fire risk (F), impact risk (H), natural and meteorological disaster risk (N), hazardous chemicals risk (C), and structure / component disease risk (D). This code position first displays the typical risk source types that may occur.

[0115] Risk source: The second digit is the detailed risk cause corresponding to the first typical risk source type. For example, the detailed risk sources corresponding to fire risk F include: illegal stacking of combustible / flammable / explosive materials (A), spontaneous combustion of ordinary passenger / truck vehicles (B), spontaneous combustion / leakage of hazardous chemicals vehicles (C), spontaneous combustion of cargo ships (D), arson (E), burning of wires / electrical short circuits (F), and excessive fire during construction (G). Based on this digit, the source of the first major risk can be confirmed, which helps to further confirm the impact of the risk on the structure. The risk sources corresponding to other types of risks are summarized in Table 1:

[0116] Table 1

[0117] .

[0118] The span where the cable is located: Since the main beam structure of the cable-supported bridge is divided into the main span and the side span, the stress characteristics of different span directions are different, and the impact of damage on the structure is also different, so its main location must be marked. The span where the damaged cable is located consists of two codes. The first code position is the main span (M) or the side span (S), and the second code position is the span number (1, 2, 3, ...). For a single-tower cable-stayed bridge, there is one main span and one side span; for a double-tower cable-stayed bridge or suspension bridge, there is one main span and two side spans; for a multi-tower cable-stayed bridge or suspension bridge, there are often multiple main spans and two side spans, and the same is true for other types of cable system bridges. Therefore, the location of the damaged cable is quickly located through the two coding positions.

[0119] Upstream and downstream sides: For a single-cable-plane cable-stayed bridge, it is generally the central cable plane, and the coding position is the central cable (M); for a double-cable-plane cable-stayed bridge or suspension bridge, its upstream and downstream positions are located by the upstream side (U) and downstream side (D).

[0120] Functional division and numbering: In cable bridges, the cables will bear different loads due to their different lengths and distances from the bridge towers. The degree of influence on the overall structural stress after damage is also different. Therefore, the last two codes are specific codes, and each bridge has a different coding result. The first code is divided into major categories by comparing the cables of the entire bridge. For example, the cables are divided into short cables (S), medium cables (M) and long cables (L) according to their length. The second code is the specific number of the cable, such as 1, 2, 3, ...

[0121] According to the above coding rules, the following coding case NA-M1-UL.25 represents that the No. 25 cable on the upstream side of the first main span of the bridge was damaged or responded abnormally due to wind-induced vibration in natural disasters. This coding can quickly identify the cause of the risk and the location of the damage and transmit information. In addition, the functional classification information of the cable (main span cable and its specific number) contained in the code can be combined with the subsequent damage identification method to directly evaluate the risk level of the cable and structure and guide the initiation of emergency response.

[0122] (2) In order to accurately determine the actual damage degree of the structure in the first time after an emergency event, the present invention proposes to put the structural damage assessment work in advance, classify and evaluate all the emergency events that have been fully identified before, and propose reasonable quantitative evaluation indicators. When the corresponding event occurs, the damage level can be quickly determined based on the correspondence between the scene and the evaluation indicators, so as to take reasonable emergency measures.

[0123] According to the statistical results of risk sources, the damage of the sling can be divided into three categories for analysis, namely: non-broken wire damage, broken wire damage and fracture damage. Then, according to the impact of the sling damage, the damage degree can be divided into the following four levels, as shown in Table 2:

[0124] Table 2

[0125] .

[0126] 1. Non-broken wire damage:

[0127] According to the statistical results of risk source identification, the possible non-broken wire damage of the sling includes apparent damage to the cable body and fire damage to the steel wire. The apparent damage does not damage the steel wire and is a level 4 damage. After the sling is burned, its mechanical properties may change, which is mainly related to the heat release rate of different fire sources and the fire time of the cable body. The fire damage of the sling can be classified into two levels, as shown in Table 3:

[0128] Table 3

[0129] .

[0130] 2. Broken wire damage:

[0131] The sling is generally composed of dozens to hundreds of steel wires. If some of the steel wires break, the safety factor of the entire cable body will decrease under the existing cable force. The specification requires that the safety factor of the cable body should be greater than 2.2 during the operation stage and greater than 1.3 during the overhaul. According to the safety factor calculation formula of a single sling:

[0132] ;

[0133] in is the standard value of tensile strength of high-strength steel wire in the cable, is the design value of the cable axial tension, is the effective cross-sectional area of ​​pure steel wire in the cable body. For the cable body at any operation stage, there are:

[0134] ;

[0135] Right now: ;

[0136] When the wire is broken, if it is in overhaul condition, , then:

[0137] ;

[0138] in Represents the effective cross-sectional area of ​​the remaining steel wires in the cable body in overhaul condition after the wire is broken. Based on this, the percentage of broken wires can be calculated as Similarly, when the wire breaks and does not meet the overhaul condition, that is, , then:

[0139] ;

[0140] in represents the effective cross-sectional area of ​​the remaining steel wires in the cable body that does not meet the overhaul condition after the wire is broken, and the percentage of broken wires is .

[0141] According to the above method, the damage level of steel wire fracture is divided as shown in Table 4:

[0142] Table 4

[0143] .

[0144] 3. Fracture damage:

[0145] When the entire cable breaks, the tension of the adjacent cables will increase and the safety factor will decrease. When the safety factor decreases to a certain extent, the steel wires of the adjacent cables will leave the elastic stage and enter the plastic stage, causing deformation that threatens the safety of the structure. When the cables in different functional areas break, the proportion of the increase in the tension of the adjacent cables is different, and the impact on the overall structure is also different. Therefore, this type of damage needs to be verified according to the functional areas in the risk source coding, and the risk level of the damage needs to be discussed. For example, for bridges that are functionally coded according to short cables, medium-long cables, and long cables, after the coding is completed, a full-bridge finite element model of the bridge must be established, and the damage risk level is discussed and verified according to the different numbers of the three types of cables.

[0146] When a single pull rope breaks, the structure is in a safety risk state that is one level higher than broken wire damage, that is, level 2 damage.

[0147] When a single cable breaks, the increase in cable force in other cables causes the corresponding cable safety factor to be less than the safety factor of 2.2 in the operation stage but greater than the safety factor of 1.33 in the overhaul state, and the structure is in the second level of damage, that is:

[0148] ;

[0149] When a single sling cable breaks, the force increment of other cables causes the corresponding cable body safety factor to be less than the safety factor requirement of 1.33 in the overhaul state, and the structure is in the first level of damage, that is:

[0150] ;

[0151] When multiple tension cables broke, the structure was in first-level damage.

[0152] According to the above rules and methods, the damage levels of the pull rope fracture are divided as shown in Table 5:

[0153] Table 5

[0154] .

[0155] Through the above damage classification and quantitative evaluation, subsequent emergency work can be carried out with a basis. When an emergency occurs, it is only necessary to compare the damage observed on site with the above content to quickly determine the structural damage and bridge safety, avoiding complex data collection and modeling verification work. Therefore, the process of the method of the present invention is summarized as follows:

[0156] The blue area is the pre-processing part before the event occurs, the red area is the event occurrence part, and the green area is the actual processing process after the event occurs.

[0157] Embodiment 3, based on the same inventive concept as other embodiments, this embodiment introduces a bridge cable damage diagnosis device based on multi-risk source identification, comprising:

[0158] The collection module is used to collect the on-site information of the bridge cable after the real bridge sends an emergency;

[0159] A determination module, used to determine a risk source identification code according to the on-site information;

[0160] The diagnosis module is used to input the risk source identification code into the pre-built damage assessment model and output the damage level and damage condition assessment of the bridge suspension cable;

[0161] The construction of the damage assessment model includes:

[0162] Count the potential risk sources of bridges, encode the potential risk sources of bridges, and obtain the risk source identification code;

[0163] Analyze the degree of damage caused by the risk source to the sling structure under each risk source identification code, and classify the damage from shallow to deep according to the degree of damage;

[0164] The classified different damages are substituted into the damage calculation model pre-constructed based on the corresponding bridge structure to obtain the overall state of the bridge structure. The safety state of the overall state of the bridge structure under different damage degrees of the components is judged according to the principle of the bridge allowable stress method. The bridge safety risk level is set based on the safety state under different damage degrees, and the relationship between component damage degree and bridge safety risk level is established to form a damage evaluation model.

[0165] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0166] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0167] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0168] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0169] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A bridge cable damage diagnosis method based on multi-risk source identification, characterized in that: include: Collecting on-site information of the bridge cable after the real bridge sends an emergency event, determining the risk source identification code according to the on-site information, inputting the risk source identification code into a pre-built damage assessment model, and outputting the damage level and damage condition assessment of the bridge cable; The construction of the damage assessment model includes: Count the potential risk sources of bridges, encode the potential risk sources of bridges, and obtain the risk source identification code; Analyze the degree of damage caused by the risk source to the sling structure under each risk source identification code, and classify the damage from shallow to deep according to the degree of damage; Substitute the classified different damages into the damage calculation model pre-built based on the corresponding bridge structure to obtain the overall state of the bridge structure. According to the principle of the bridge allowable stress method, the safety state of the overall state of the bridge structure under different damage degrees of the components is judged. The bridge safety risk level is set based on the safety state under different damage degrees, and the relationship between the component damage degree and the bridge safety risk level is established to form a damage evaluation model. The step of determining the risk source identification code according to the on-site information includes: Obtain the risk source type, risk source, span where the cable is located, upstream and downstream sides, cable function division and number from the on-site information of the bridge cable; According to the preset coding sequence and coding symbols, the risk source type, risk source, span where the sling is located, upstream and downstream sides, sling function division and number are coded in sequence to obtain the risk source identification code; The counting of potential risk sources of bridges and encoding of potential risk sources of bridges to obtain risk source identification codes include: The risk source type, risk source, span where the pull rope is located, upstream and downstream sides, functional divisions and numbers are coded in sequence to form a risk source identification code; The risk source type is a first code, which is encoded according to fire risk, impact risk, natural and meteorological disaster risk, hazardous chemical risk, and structure / component disease risk; The risk source is the second code, which is coded based on illegal stacking of combustible / flammable / explosive materials, spontaneous combustion of ordinary passenger / truck vehicles, spontaneous combustion / leakage of hazardous chemicals vehicles, spontaneous combustion of cargo ships, arson, burning of wires / electrical short circuits, and excessive fire during construction operations; The span where the pull rope is located is a third code and a fourth code, the third code is encoded according to the type of the main span / side span, and the fourth code is encoded according to the span number of the main span / side span; The upstream and downstream sides are fifth codes, and the fifth codes are encoded according to the cable surface position of the cable-stayed bridge; The functional divisions and numbers are the sixth code and the seventh code. The sixth code is encoded according to the contrasting features of the pull rope, and the seventh code is encoded according to the specific number of the pull rope.

2. The bridge cable damage diagnosis method based on multi-risk source identification according to claim 1 is characterized in that: Also includes: Response levels, response measures and control methods corresponding to the response levels are set based on different bridge safety risk levels.

3. The bridge cable damage diagnosis method based on multi-risk source identification according to claim 1 is characterized in that: The setting of the bridge safety risk level based on the safety status under different damage degrees includes: Analyze the damage degree of the sling to determine the damage category, which includes: non-broken wire damage, broken wire damage and fracture damage; The degree of damage is graded based on the damage category, and the degree of damage is graded from severe to mild, including level one damage, level two damage, level three damage, and level four damage; the non-broken wire damage belongs to level three damage or level four damage; the broken wire damage belongs to level three damage or level four damage; the fracture damage belongs to level one damage or level two damage.

4. The bridge cable damage diagnosis method based on multi-risk source identification according to claim 3 is characterized in that: Determining the damage level of the non-broken wire damage includes: Collect the fire time, temperature and PE sheath condition of the sling; When the fire time is not less than the first time threshold and the temperature is not less than the first temperature threshold, the damage level of the non-broken wire damage is determined to be level three damage; When the fire time is lower than the first time threshold and the temperature is lower than the first temperature threshold, the damage level of the non-broken wire damage is determined to be level 4 damage; When the fire time is not less than the second time threshold and the temperature is less than the second temperature threshold, the damage level of the non-broken wire damage is determined to be level 4 damage, wherein the second time threshold is greater than the first time threshold, and the second temperature threshold is less than the first temperature threshold; The PE sheath of the sling was damaged but the steel wire of the sling was not damaged. The damage level of non-broken wire damage was determined to be level four.

5. The bridge cable damage diagnosis method based on multi-risk source identification according to claim 3 is characterized in that: Determining the damage level of the broken wire damage includes: The effective cross-sectional area of ​​the remaining steel wire in the sling after collecting the broken wire ; Obtain the standard value of the tensile strength of the steel wire of the sling , Design value of axial tension of the cable ; The safety factor of the rope body of the rope after the wire is broken is calculated by the following formula: K , ； When the safety factor of the cable body is calculated K Not greater than the first safety factor threshold K 1, the damage level of broken wire damage is determined to be level 3 damage; When the safety factor of the cable body is calculated K Greater than the first safety factor threshold K 1 and not greater than the second safety factor threshold K 2, the damage level of broken wire damage is determined to be level 4 damage, among which the second safety factor threshold K 2 is greater than the first safety factor threshold K 1.

6. The bridge cable damage diagnosis method based on multi-risk source identification according to claim 3 is characterized in that: Determining the damage level of the fracture damage includes: When a single sling breaks, determine the force increment of other cables ; Obtain the standard value of the tensile strength of the steel wire of the sling , Design value of axial tension of the cable , the effective cross-sectional area of ​​pure steel wire in the cable body of the sling ; The safety factor of other cables is calculated using the following formula: K , ； When calculating the cable body safety factor of other cables K Greater than the first safety factor threshold K 1 and not greater than the second safety factor threshold K 2, the damage level of the fracture damage is determined to be secondary damage, where the second safety factor threshold K 2 is greater than the first safety factor threshold K 1; When calculating the cable body safety factor of other cables K Not greater than the first safety factor threshold K 1, the damage level of the broken wire damage is determined to be level one damage.

7. The bridge cable damage diagnosis method based on multi-risk source identification according to claim 6 is characterized in that: Determining the cable force increment of other cable bodies ,include: Obtain design information of the target bridge; Establish the finite element model of the whole bridge based on the design data; By removing the corresponding cable body in the finite element model of the whole bridge, the cable fracture condition is simulated and the cable force increment of other cables after fracture relative to before fracture is obtained.

8. A bridge cable damage diagnosis device based on multi-risk source identification, characterized in that: include: The collection module is used to collect the on-site information of the bridge cable after the real bridge sends an emergency; A determination module, used to determine a risk source identification code according to the on-site information; The diagnosis module is used to input the risk source identification code into the pre-built damage assessment model and output the damage level and damage condition assessment of the bridge suspension cable; The construction of the damage assessment model includes: Count the potential risk sources of bridges, encode the potential risk sources of bridges, and obtain the risk source identification code; Analyze the degree of damage caused by the risk source to the sling structure under each risk source identification code, and classify the damage from shallow to deep according to the degree of damage; Substitute the classified different damages into the damage calculation model pre-built based on the corresponding bridge structure to obtain the overall state of the bridge structure. According to the principle of the bridge allowable stress method, the safety state of the overall state of the bridge structure under different damage degrees of the components is judged. The bridge safety risk level is set based on the safety state under different damage degrees, and the relationship between the component damage degree and the bridge safety risk level is established to form a damage evaluation model. The step of determining the risk source identification code according to the on-site information includes: Obtain the risk source type, risk source, span where the cable is located, upstream and downstream sides, cable function division and number from the on-site information of the bridge cable; According to the preset coding sequence and coding symbols, the risk source type, risk source, span where the sling is located, upstream and downstream sides, sling function division and number are coded in sequence to obtain the risk source identification code; The counting of potential risk sources of bridges and encoding of potential risk sources of bridges to obtain risk source identification codes include: The risk source type, risk source, span where the pull rope is located, upstream and downstream sides, functional divisions and numbers are coded in sequence to form a risk source identification code; The risk source type is a first code, which is encoded according to fire risk, impact risk, natural and meteorological disaster risk, hazardous chemical risk, and structure / component disease risk; The risk source is the second code, which is coded based on illegal stacking of combustible / flammable / explosive materials, spontaneous combustion of ordinary passenger / truck vehicles, spontaneous combustion / leakage of hazardous chemicals vehicles, spontaneous combustion of cargo ships, arson, burning of wires / electrical short circuits, and excessive fire during construction operations; The span where the pull rope is located is a third code and a fourth code, the third code is encoded according to the type of the main span / side span, and the fourth code is encoded according to the span number of the main span / side span; The upstream and downstream sides are fifth codes, and the fifth codes are encoded according to the cable surface position of the cable-stayed bridge; The functional divisions and numbers are the sixth code and the seventh code. The sixth code is encoded according to the contrasting features of the pull rope, and the seventh code is encoded according to the specific number of the pull rope.

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