CN112633633B - Method and device for identifying and evaluating gas pipeline-bridge coupling hidden danger - Google Patents

Abstract

The invention discloses a method and a device for identifying and evaluating coupling hidden dangers of a gas pipeline and a bridge, wherein the method comprises the following steps: acquiring a gas pipeline leakage possibility score; acquiring a first evaluation parameter of a bridge fire caused by gas leakage; acquiring a second evaluation parameter of the bridge influenced by the underground space explosion, wherein the second evaluation parameter comprises an explosion damage possibility judgment coefficient, a score value of bridge explosion vulnerability and a result value of the bridge influenced by the underground space explosion; acquiring an emergency rescue factor; calculating the risk level according to the gas pipeline leakage possibility score, a first evaluation parameter of bridge fire caused by gas leakage, a second evaluation parameter of the bridge influenced by underground space explosion and an emergency rescue factor; the invention has the advantages that: provided are a method and a device for identifying coupling hidden dangers of a gas pipeline and a bridge and evaluating corresponding risks.

Description

Method and device for identifying and evaluating gas pipeline-bridge coupling hidden danger

Technical Field

The invention relates to the technical field of gas safety supervision, in particular to a method and a device for identifying and evaluating coupling hidden dangers of a gas pipeline and a bridge.

Background

With the increasing progress of urbanization, cities face more and more public safety risks, and great threats are brought to the normal development of the urban society and economy. Due to interdependency and mutual restriction relationship in and among social systems, a linkage effect is often generated, which shows that the occurrence of a disaster together can cause the successive occurrence of a series of secondary disasters. When the two risks are converged, the uncertain state of the two risks is amplified. The impact also spreads from one geographical space to another, broader geographical space.

In recent municipal engineering construction, the connection between lifeline engineering and urban road and bridge construction is tighter, and the distance is closer. Once the gas pipeline leaks, the surrounding facilities are easily damaged by the jet fire, the underground space explosion and the like caused by the gas pipeline, and a coupling risk is formed. The bridge damage event caused by the leakage and explosion of the gas pipeline occurs, the gas pipeline is damaged by the removal of the bridge damage event in 2018, 3 months in the world, Jiangxi Jingdezhen, the leakage gas diffuses to the drainage pipeline and is accumulated and exploded, so that one person dies, and the peripheral bridge is also seriously damaged. In 9 months in 2018, at the intersection of the great road of Hefeizhou and the water Yangjiang river, the third party works to cause the leakage of a gas pipeline to cause a fire, thereby damaging a nearby overpass. Therefore, the method is particularly important for identifying the coupling hidden danger of the gas pipeline and the bridge and evaluating the corresponding risk.

Chinese patent application No. CN202010303580.7 discloses a method and device for matching gas risk assessment and safety supervision resources, wherein the method comprises: collecting gas risk assessment data; cleaning the collected gas risk assessment to obtain cleaned data; determining a risk evaluation area, and meshing the risk evaluation area according to the size of a preset mesh; obtaining scores of the cleaned data in the grids; determining index weight based on an analytic hierarchy process, judging whether consistency check is passed, and if the consistency check is passed, carrying out grid risk calculation; and acquiring the safety supervision resources, and matching the safety supervision resources to obtain the safety supervision resources in each grid. The patent application mainly relates to gas risk assessment, and does not relate to identification of coupling hidden dangers of gas pipelines and bridges, and does not relate to assessment of corresponding risks.

Disclosure of Invention

The invention aims to solve the technical problem that methods and devices for identifying the coupling hidden danger of a gas pipeline and a bridge and evaluating the corresponding risk are lacked in the prior art.

The invention solves the technical problems through the following technical means: a method for identifying and evaluating a gas pipeline-bridge coupling hidden danger, the method comprising:

the method comprises the following steps: acquiring a gas pipeline leakage possibility score, wherein the gas pipeline leakage possibility score comprises a pipeline large leakage possibility score and a pipeline tiny leakage possibility score;

step two: acquiring first evaluation parameters of bridge fire caused by gas leakage, wherein the first evaluation parameters comprise a fire damage possibility judgment coefficient, a bridge fire vulnerability score value and a bridge influence consequence value of gas pipeline leakage fire to the bridge;

step three: acquiring a second evaluation parameter of the bridge influenced by the underground space explosion, wherein the second evaluation parameter comprises an explosion damage possibility judgment coefficient, a score value of bridge explosion vulnerability and a result value of the bridge influenced by the underground space explosion;

step four: acquiring an emergency rescue factor;

step five: and calculating the risk level according to the gas pipeline leakage possibility score, a first evaluation parameter of the bridge fire caused by gas leakage, a second evaluation parameter of the bridge influenced by underground space explosion and an emergency rescue factor.

The invention establishes a method for identifying the hidden coupling danger of the gas pipeline and the bridge and evaluating the risk, and evaluates the coupling risk of the gas pipeline and the bridge in three aspects of the possibility of leakage of the gas pipeline, the vulnerability of the bridge caused by fire/explosion due to gas leakage and the consequences caused by the fire/explosion.

Further, the process of obtaining the score of the possibility of large amount of leakage of the pipeline in the first step is as follows:

by the formula

Obtaining a leakage frequency based on pipeline information, wherein P_GIndicating the leakage frequency, P, based on pipeline information_diIndicating the leakage frequency, P, of a pipe section of diameter di_fiIndicating a leakage frequency, P, of fi, which is the pipe segment covering depth_hiIndicating the leakage frequency, P, of the pipe section wall thickness hi_dmaxRepresenting the maximum leakage frequency, P, of pipe sections of different diameters_fmaxRepresenting the maximum leakage frequency, P, at different coating depths of the pipe section_hmaxIndicating the maximum leakage frequency, mu, at different pipe wall thicknesses of the pipe section₁Indicating a correction factor, mu, for the type of material of the pipe₂Indicates the construction activity degree and mu₂＝μ₂₁*w₁+μ₂₂*w₂，μ₂₁Represents the distance, w, of the construction site from the gas pipeline to be evaluated₁Represents the first weight and has a value of 0.6, mu₂₂Indicating construction controllability correction factor, w₂Represents a second weight and has a value of 0.4;

by the formula

Obtaining a third party breach leak frequency final score based on pipeline information, wherein Q₁₁Represents the third party corruption leakage frequency final score, min (P)_G) Represents the minimum value of the whole-market gas pipe section, max (P)_G) The maximum value of the term of the fuel gas pipe section of the whole city is shown;

by the formula Q₁＝Q₁₁α₁+Q₁₂α₂Obtaining a score of the likelihood of a large leak in the pipe, wherein Q₁Represents a pipeline high leak probability score, Q₁₂Representing the final score value, alpha, of the probability of a leak due to a geological disaster₁The weight which represents the large amount of leakage caused by the third-party construction is 0.8; alpha is alpha₂The weight of the large leakage caused by geological disaster is 0.2.

Further, the process of obtaining the score of the probability of the small leakage of the pipeline in the first step is as follows:

by the formula Q₂＝Q₂₁α₃+Q₂₂α₄Obtaining a score of the possibility of a micro-leak in the pipe, wherein Q₂Indicates a score of a possible minute leakage of the pipe, Q₂₁Indicates the corrosion score, α₃Represents a weight of a small leakage caused by corrosion and has a value of 0.5, Q₂₂Indicates the material defect score, alpha₄Indicating that the material defect caused a minor leakage weight and has a value of 0.5.

Further, the acquiring process of the fire damage possibility judgment coefficient in the second step is as follows:

calculating the thermal radiation flux of the bridge caused by gas pipeline leakage by adopting a jet fire model, and taking 12.5KW/m²As the threshold value of the thermal radiation flux of the bridge, when the bridge is obtained by calculationWhen the thermal radiation flux exceeds the threshold value of the thermal radiation flux of the bridge, the judgment coefficient lambda of the possibility of fire damage is obtained₁Is 1, otherwise is 0.1, and when the possibility of fire damage is judged, the coefficient lambda is₁When the value is 1, the hidden danger that the bridge is damaged due to gas pipeline leakage exists, wherein the injection fire model is an API521 model or a THORNTON model.

Further, the second step includes a process of acquiring the score value of the fire vulnerability of the bridge:

by the formula V₁＝V₁₁ψ₁₁+V₁₂ψ₁₂+V₁₃ψ₁₃+V₁₄ψ₁₄Obtaining a fire vulnerability score value of the bridge, wherein V₁Represents the value of the vulnerability of the bridge to fire, V₁₁Indicating the vulnerability score, psi, caused by the material type₁₁Represents a third weight and takes 0.3, V₁₂Indicating the vulnerability score, psi, caused by the structural member₁₂Represents a fourth weight and takes 0.2, V₁₃Indicating the vulnerability score, psi, due to age₁₃Represents a fifth weight and takes 0.2, V₁₄Indicates the vulnerability score, psi, resulting from the current rating₁₄Represents the sixth weight and takes 0.3.

Further, in the second step, the obtaining process of the influence consequence value of the gas pipeline leakage fire on the bridge is as follows: by the formula C₁＝C₁₁φ₁+C₁₂φ₂Obtaining the influence consequence value of the gas pipeline leakage fire on the bridge, wherein C₁Value representing the consequences of a gas pipeline leakage fire on the bridge, C₁₁Indicating a value of life and property loss, phi₁Representing the weight of the loss of life and property, C₁₂Represents a traffic demand impact value and C₁₂＝C₃₁×ε₃₁+C₃₂×ε₃₂+C₃₃×ε₃₃，C₃₁Representing the influence of passenger-vehicle flow, C₃₂Score value, C, corresponding to distance to alternate route₃₃Representing the corresponding score value, epsilon, of the bridge service function_iIs a weight factor of the i-th index and epsilon₃₁，ε₃₂，ε₃₃Respectively 0.2, 0.4 and 0.4,φ₂representing the weight taken by the traffic demand impact value.

Further, the process of obtaining the explosion damage possibility judgment coefficient in the third step is as follows:

when the shortest distance between the gas pipeline and the water drainage pipeline is smaller than Rmax, a first judgment coefficient lambda 21 is equal to 1, otherwise, the distance is 0.1, the water drainage pipeline has a safe burial depth, if the actual burial depth of the water drainage pipeline is larger than the safe burial depth, overpressure damage cannot be caused to a ground disaster bearing body, a second judgment coefficient lambda 22 is equal to 0.1, otherwise, overpressure damage can be caused to the ground disaster bearing body, the second judgment coefficient lambda 22 is equal to 1, an explosion damage possibility judgment coefficient lambda 2 is equal to the product of the first judgment coefficient lambda 21 and the second judgment coefficient lambda 22, and when the explosion damage possibility judgment coefficient lambda 2 is 1, bridge damage hidden danger caused by gas pipeline leakage underground space aggregation explosion is considered to exist;

wherein, the safe burial depth calculation process is as follows:

by the formula

Obtaining a relation between the safe buried depth and the equivalent diameter, wherein H_safeFor safe burial depth D_eIs an equivalent diameter and

S₀is the sectional area of the pipeline, and C is the circumference of the pipeline;

for a connecting line with a circular cross-section, S₀＝0.785D²And D represents the pipe diameter;

for connecting lines of approximately rectangular cross-section, S₀W denotes the rectangular cross-section line width, and H denotes the rectangular cross-section line height.

Further, the fourth step includes:

by the formula

Obtaining the emergency capacity value of an engineering emergency team, wherein beta₁Representing the emergency capacity value of the engineering rescue team,

denotes a seventh weight coefficient, d_iThe distance between the emergency disposal unit and the to-be-evaluated gas pipe section is represented, and m represents a correction coefficient;

by the formula β ═ β₁v₁+β₂v₂Obtaining an emergency rescue factor, wherein beta represents the emergency rescue factor, v₁Representing the weight corresponding to the emergency capacity value of the engineering rescue team and taking the value of 0.6, beta₂Indicating the value of fire emergency capability, v₂And the weight corresponding to the fire emergency capacity value is represented and the value is 0.4.

Further, the fifth step includes:

by the formula

Acquiring a risk value of the fire to the bridge, wherein xi₁₁、ξ₁₂、σ₁₁、σ₁₂、σ₁₃The weights are respectively 0.9, 0.1, 0.3 and 0.4;

by the formula

Acquiring a risk value of explosion to the bridge, wherein xi₂₁、ξ₂₂、σ₁₁、σ₁₂、σ₁₃The weights are respectively 0.1, 0.9, 0.3 and 0.4;

by the formula R ═ R₁κ₁+R₂κ₂Obtaining a pipeline-bridge coupling risk value, wherein k₁Representing the weight of the fire on the risk value of the bridge, and taking the value as 0.6; kappa₂The weight of the risk value of the explosion to the bridge is represented, and the value is 0.4.

The invention also provides a device for identifying and evaluating the coupling hidden danger of the gas pipeline and the bridge, which comprises:

the gas pipeline leakage possibility score acquisition module is used for acquiring a gas pipeline leakage possibility score, wherein the gas pipeline leakage possibility score comprises a pipeline large leakage possibility score and a pipeline tiny leakage possibility score;

the second acquisition module is used for acquiring first evaluation parameters of the bridge fire caused by gas leakage, wherein the first evaluation parameters comprise a fire damage possibility judgment coefficient, a bridge fire vulnerability score value and a bridge influence consequence value of the gas pipeline leakage fire to the bridge;

the third acquisition module is used for acquiring a second evaluation parameter of the bridge influenced by the underground space explosion, wherein the second evaluation parameter comprises an explosion damage possibility judgment coefficient, a bridge explosion vulnerability score value and an influence result value of the underground space explosion on the bridge;

the fourth acquisition module is used for acquiring emergency rescue factors;

and the risk evaluation module is used for calculating the risk level according to the gas pipeline leakage possibility score, the first evaluation parameter of the bridge fire caused by gas leakage, the second evaluation parameter of the bridge influenced by underground space explosion and the emergency rescue factor.

Further, the process of obtaining the score of the possibility of the large number of leaks in the pipeline in the first obtaining module is as follows:

by the formula

Obtaining a leakage frequency based on pipeline information, wherein P_GIndicating the leakage frequency, P, based on pipeline information_diIndicating the leakage frequency, P, of a pipe section of diameter di_fiIndicating a leakage frequency, P, of fi, which is the pipe segment covering depth_hiIndicating the leakage frequency, P, of the pipe section wall thickness hi_dmaxRepresenting the maximum leakage frequency, P, of pipe sections of different diameters_fmaxRepresenting the maximum leakage frequency, P, at different coating depths of the pipe section_hmaxIndicating the maximum leakage frequency, mu, at different pipe wall thicknesses of the pipe section₁Indicating a correction factor, mu, for the type of material of the pipe₂Indicates the construction activity degree and mu₂＝μ₂₁*w₁+μ₂₂*w₂，μ₂₁Represents the distance, w, of the construction site from the gas pipeline to be evaluated₁Represents the first weight and has a value of 0.6, mu₂₂To representConstruction controllability correction factor, w₂Represents a second weight and has a value of 0.4;

by the formula

Obtaining a third party breach leak frequency final score based on pipeline information, wherein Q₁₁Represents the third party corruption leakage frequency final score, min (P)_G) Represents the minimum value of the whole-market gas pipe section, max (P)_G) The maximum value of the term of the fuel gas pipe section of the whole city is shown;

by the formula Q₁＝Q₁₁a₁+Q₁₂α₂Obtaining a score of the likelihood of a large leak in the pipe, wherein Q₁Represents a pipeline high leak probability score, Q₁₂Representing the final score value, alpha, of the probability of a leak due to a geological disaster₁The weight which represents the large amount of leakage caused by the third-party construction is 0.8; alpha is alpha₂The weight of the large leakage caused by geological disaster is 0.2.

Further, the acquisition process of the score of the possibility of the micro leakage of the pipeline in the first acquisition module is as follows:

by the formula Q₂＝Q₂₁α₃+Q₂₂α₄Obtaining a score of the possibility of a micro-leak in the pipe, wherein Q₂Indicates a score of a possible minute leakage of the pipe, Q₂₁Indicates the corrosion score, α₃Represents a weight of a small leakage caused by corrosion and has a value of 0.5, Q₂₂Indicates the material defect score, alpha₄Indicating that the material defect caused a minor leakage weight and has a value of 0.5.

Further, the acquiring process of the fire damage possibility judgment coefficient in the second acquiring module is as follows:

calculating the thermal radiation flux of the bridge caused by gas pipeline leakage by adopting a jet fire model, and taking 12.5KW/m²As a bridge thermal radiation flux threshold, when the calculated thermal radiation flux borne by the bridge exceeds the bridge thermal radiation flux threshold, the fire damage possibility judgment coefficient lambda is obtained₁Is 1, otherwise is 0.1, and when the possibility of fire damage is judged, the coefficient lambda is₁When the value is 1, the hidden danger that the bridge is damaged due to gas pipeline leakage exists, wherein the injection fire model is an API521 model or a THORNTON model.

Further, the process of acquiring the score value of the fire vulnerability of the bridge in the second acquisition module is as follows:

by the formula V₁＝V₁₁ψ₁₁+V₁₂ψ₁₂+V₁₃ψ₁₃+V₁₄ψ₁₄Obtaining a fire vulnerability score value of the bridge, wherein V₁Represents the value of the vulnerability of the bridge to fire, V₁₁Indicating the vulnerability score, psi, caused by the material type₁₁Represents a third weight and takes 0.3, V₁₂Indicating the vulnerability score, psi, caused by the structural member₁₂Represents a fourth weight and takes 0.2, V₁₃Indicating the vulnerability score, psi, due to age₁₃Represents a fifth weight and takes 0.2, V₁₄Indicates the vulnerability score, psi, resulting from the current rating₁₄Represents the sixth weight and takes 0.3.

Further, the acquiring process of the bridge influence consequence value of the gas pipeline leakage fire in the second acquiring module is as follows: by the formula C₁＝C₁₁φ₁+C₁₂φ₂Obtaining the influence consequence value of the gas pipeline leakage fire on the bridge, wherein C₁Value representing the consequences of a gas pipeline leakage fire on the bridge, C₁₁Indicating a value of life and property loss, phi₁Representing the weight of the loss of life and property, C₁₂Represents a traffic demand impact value and C₁₂＝C₃₁×ε₃₁+C₃₂×ε₃₂+C₃₃×ε₃₃，C₃₁Representing the influence of passenger-vehicle flow, C₃₂Score value, C, corresponding to distance to alternate route₃₃Representing the corresponding score value, epsilon, of the bridge service function_iIs a weight factor of the i-th index and epsilon₃₁，ε₃₂，ε₃₃Respectively 0.2, 0.4, phi₂Representing the weight taken by the traffic demand impact value.

Further, the process of acquiring the explosion damage possibility judgment coefficient in the third acquiring module is as follows:

when the shortest distance between the gas pipeline and the water drainage pipeline is smaller than Rmax, a first judgment coefficient lambda 21 is equal to 1, otherwise, the distance is 0.1, the water drainage pipeline has a safe burial depth, if the actual burial depth of the water drainage pipeline is larger than the safe burial depth, overpressure damage cannot be caused to a ground disaster bearing body, a second judgment coefficient lambda 22 is equal to 0.1, otherwise, overpressure damage can be caused to the ground disaster bearing body, the second judgment coefficient lambda 22 is equal to 1, an explosion damage possibility judgment coefficient lambda 2 is equal to the product of the first judgment coefficient lambda 21 and the second judgment coefficient lambda 22, and when the explosion damage possibility judgment coefficient lambda 2 is 1, bridge damage hidden danger caused by gas pipeline leakage underground space aggregation explosion is considered to exist;

wherein, the safe burial depth calculation process is as follows:

by the formula

Obtaining a relation between the safe buried depth and the equivalent diameter, wherein H_safeFor safe burial depth D_eIs an equivalent diameter and

S₀is the sectional area of the pipeline, and C is the circumference of the pipeline;

for a connecting line with a circular cross-section, S₀＝0.785D²And D represents the pipe diameter;

for connecting lines of approximately rectangular cross-section, S₀W denotes the rectangular cross-section line width, and H denotes the rectangular cross-section line height.

Further, the fourth obtaining module includes:

by the formula

Obtaining the emergency capacity value of an engineering emergency team, wherein beta₁Representing the emergency capacity value of the engineering rescue team,

denotes a seventh weight coefficient, d_iThe distance between the emergency disposal unit and the to-be-evaluated gas pipe section is represented, and m represents a correction coefficient;

by the formula β ═ β₁v₁+β₂v₂Obtaining an emergency rescue factor, wherein beta represents the emergency rescue factor, v₁Representing the weight corresponding to the emergency capacity value of the engineering rescue team and taking the value of 0.6, beta₂Indicating the value of fire emergency capability, v₂And the weight corresponding to the fire emergency capacity value is represented and the value is 0.4.

Further, the risk assessment module comprises:

by the formula

Acquiring a risk value of the fire to the bridge, wherein xi₁₁、ξ₁₂、σ₁₁、σ₁₂、σ₁₃The weights are respectively 0.9, 0.1, 0.3 and 0.4;

by the formula

Acquiring a risk value of explosion to the bridge, wherein xi₂₁、ξ₂₂、σ₁₁、σ₁₂、σ₁₃The weights are respectively 0.1, 0.9, 0.3 and 0.4;

by the formula R ═ R₁κ₁+R₂κ₂Obtaining a pipeline-bridge coupling risk value, wherein k₁Representing the weight of the fire on the risk value of the bridge, and taking the value as 0.6; kappa₂The weight of the risk value of the explosion to the bridge is represented, and the value is 0.4.

The invention has the advantages that: the invention establishes a method for identifying the hidden coupling danger of the gas pipeline and the bridge and evaluating the risk, and evaluates the coupling risk of the gas pipeline and the bridge in three aspects of the possibility of leakage of the gas pipeline, the vulnerability of the bridge caused by fire/explosion due to gas leakage and the consequences caused by the fire/explosion.

Drawings

Fig. 1 is a flowchart of a method for identifying and evaluating a gas pipeline-bridge coupling risk according to an embodiment of the present invention;

fig. 2 is a logic process diagram of a method for identifying and evaluating a gas pipeline-bridge coupling risk according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

As shown in fig. 1 and fig. 2, the present invention provides a method for identifying and evaluating a gas pipeline-bridge coupling hidden danger, the method comprising:

step S1: acquiring a gas pipeline leakage possibility score, wherein the gas pipeline leakage possibility score comprises a pipeline large leakage possibility score and a pipeline tiny leakage possibility score;

in step S1, the process of acquiring the score of the possibility of a large number of leaks in the pipeline is as follows:

and (3) third-party construction: the pipeline third party construction foundation leakage probability values are calculated as shown in the following table.

TABLE 1 pipeline third party construction foundation leakage probability value calculation

The leak probability correction factors are shown in the following table.

TABLE 2 correction factor for leak probability values

In combination with the results of tables 1 and 2,by the formula

Obtaining a leakage frequency based on pipeline information, wherein P_GIndicating the leakage frequency, P, based on pipeline information_diIndicating the leakage frequency, P, of a pipe section of diameter di_fiIndicating a leakage frequency, P, of fi, which is the pipe segment covering depth_hiIndicating the leakage frequency, P, of the pipe section wall thickness hi_dmaxRepresenting the maximum leakage frequency, P, of pipe sections of different diameters_fmaxRepresenting the maximum leakage frequency, P, at different coating depths of the pipe section_hmaxIndicating the maximum leakage frequency, mu, at different pipe wall thicknesses of the pipe section₁Indicating a correction factor, mu, for the type of material of the pipe₂Indicates the construction activity degree and mu₂＝μ₂₁*w₁+μ₂₂*w₂，μ₂₁Represents the distance, w, of the construction site from the gas pipeline to be evaluated₁Represents the first weight and has a value of 0.6, mu₂₂Indicating construction controllability correction factor, w₂Represents a second weight and has a value of 0.4;

by the formula

Obtaining a third party breach leak frequency final score based on pipeline information, wherein Q₁₁Represents the third party corruption leakage frequency final score, min (P)_G) Represents the minimum value of the whole-market gas pipe section, max (P)_G) The maximum value of the term of the fuel gas pipe section of the whole city is shown;

geological disaster:

the pipeline geological disaster base leakage probability values are calculated as shown in the following table.

TABLE 3 pipeline geological disaster base leak probability value calculation

The leak probability correction factors are shown in the following table.

TABLE 4 correction factor for leak probability values

The calculation of the leakage probability caused by the geological disaster is consistent with the third-party construction, so that the detailed description is omitted.

Combining tables 3 and 4, by formula Q₁＝Q₁₁α₁+Q₁₂α₂Obtaining a score of the likelihood of a large leak in the pipe, wherein Q₁Represents a pipeline high leak probability score, Q₁₂Representing the final score value, alpha, of the probability of a leak due to a geological disaster₁The weight which represents the large amount of leakage caused by the third-party construction is 0.8; alpha is alpha₂The weight of the large leakage caused by geological disaster is 0.2.

The process of acquiring the score of the possibility of a small leak in the pipe in step S1 is as follows:

the pipeline corrosion base leak probability values are calculated as shown in the following table.

TABLE 5 calculation of pipeline Corrosion basis probability

The leak probability correction factors are shown in the following table.

TABLE 6 leak probability correction factor

TABLE 7 probability of material defect basis leakage

TABLE 8 leak probability correction factor

The calculation of the leakage probability caused by corrosion and material defects is consistent with that of third-party construction, so that the detailed description is omitted. The weight of the corrosion and material defect indicators is shown in the following table.

TABLE 9 weights corresponding to indexes of respective levels

Note: if the actual index data can not be acquired, the weight equal ratio is distributed to the index corresponding to the acquirable data.

Combining tables 5 to 9, by formula Q₂＝Q₂₁α₃+Q₂₂α₄Obtaining a score of the possibility of a micro-leak in the pipe, wherein Q₂Indicates a score of a possible minute leakage of the pipe, Q₂₁Indicates the corrosion score, α₃Represents a weight of a small leakage caused by corrosion and has a value of 0.5, Q₂₂Indicates the material defect score, alpha₄Indicating that the material defect caused a minor leakage weight and has a value of 0.5.

Step S2: acquiring first evaluation parameters of bridge fire caused by gas leakage, wherein the first evaluation parameters comprise a fire damage possibility judgment coefficient, a bridge fire vulnerability score value and a bridge influence consequence value of gas pipeline leakage fire to the bridge;

the acquiring process of the fire damage possibility judgment coefficient in the step S2 is as follows:

the main failure mechanism of a jet fire to a bridge is thermal radiation. And judging whether the bridge is damaged or not according to a heat flux criterion, wherein the heat flux criterion is shown in a table 10. Adopting a universal fire injection model at home and abroadCalculating the heat radiation flux borne by the bridge due to the leakage of the gas pipeline, and taking 12.5KW/m²As a bridge thermal radiation flux threshold, when the calculated thermal radiation flux borne by the bridge exceeds the bridge thermal radiation flux threshold, the fire damage possibility judgment coefficient lambda is obtained₁Is 1, otherwise is 0.1, and when the possibility of fire damage is judged, the coefficient lambda is₁When the value is 1, the hidden danger that the bridge is damaged due to gas pipeline leakage exists, wherein the injection fire model is an API521 model or a THORNTON model.

TABLE 10 thermal radiation flux injury guidelines

The process of obtaining the score value of the fire vulnerability of the bridge in the step S2 is as follows:

the section selects four aspects of the material type of the bearing body bridge, the damaged structural member, the service life and the current bridge rating to evaluate the vulnerability of the bridge. By the formula V₁＝V₁₁ψ₁₁+V₁₂ψ₁₂+V₁₃ψ₁₃+V₁₄ψ₁₄Obtaining a fire vulnerability score value of the bridge, wherein V₁Represents the value of the vulnerability of the bridge to fire, V₁₁Indicating the vulnerability score, psi, caused by the material type₁₁Represents a third weight and takes 0.3, V₁₂Indicating the vulnerability score, psi, caused by the structural member₁₂Represents a fourth weight and takes 0.2, V₁₃Indicating the vulnerability score, psi, due to age₁₃Represents a fifth weight and takes 0.2, V₁₄Indicates the vulnerability score, psi, resulting from the current rating₁₄Represents the sixth weight and takes 0.3.

The following explanation is made in terms of the type of the material of the supporting bridge, the damaged structural member, the service life and the rating of the current bridge.

Type of Material V₁₁

The urban bridge can be divided into four types according to the material types: reinforced concrete bridges, prestressed concrete bridges, steel-concrete composite bridges and steel bridges. The prestressed concrete is prestressed before use, so that the strength of the steel bar is reduced at high temperature, the fire resistance limit of the prestressed concrete is also reduced, and hidden danger exists in fire fighting. Steel has a high thermal conductivity and a low heat capacity compared to concrete, the temperature of steel rapidly increases in a fire, and the strength and elastic modulus of steel are very sensitive to temperature changes, and the increase in temperature causes the strength and elastic modulus of steel to rapidly decrease, resulting in a decrease in the bearing capacity of a steel member.

The bridge material type vulnerability index score is shown in table 11.

TABLE 11 materials type score Condition

Type of material (psi)1＝0.3)	Score V11
		Reinforced concrete bridge	4
Prestressed concrete bridge	6
		Steel-concrete combined bridge	8
Steel bridge	10

Structural member V₁₂

By referring to 'evaluation standards of technical conditions of highway bridges' and considering damage to urban bridges caused by fire injection, structural members such as main beams, supports, piers, bridge deck pavement and the like are selected as structural member evaluation indexes. And analyzing the bridge part directly acted by the jet fire, and obtaining the corresponding index score according to the following table.

TABLE 12 structural Member score

Structural member (psi)2＝0.2)	Score V12
		Upper general structural member (Wet joint, diaphragm, etc.)	4
Bridge pier	6
		Abutment	8
Main beam	10

Service life V₁₃

As the operating time increases, the probability of failure increases for the bridge. The unified design standard for the reliability of building structures stipulates that the service life of bridge design in China is 100 years to 120 years, and the reference document [2] divides the service life into five grades.

The bridge age vulnerability index score is shown in table 13.

TABLE 13 service life score

Service life (psi)3＝0.2)	Score V13
		＜25	2
25～50	4
		50～75	6
75～100	8
		≥100	10

Current rating V₁₄

The bridge technical condition evaluation aims to comprehensively describe the defects of all parts of the bridge, evaluate the bridge technical condition, record basic characteristics of the bridge, establish a sound bridge technical file, provide decision support for maintaining, repairing and reinforcing the bridge, enable the bridge to be in a good working state for a long time, and finally effectively manage and monitor the condition of the operated bridge.

The existing condition of the bridge is rated according to the evaluation standard of the technical condition of the highway bridge, when the rating of the bridge is low, the bridge is more easily damaged by fire due to various defects such as concrete carbonization, steel bar corrosion and the like, and therefore, the current rating of the bridge can be used as one of indexes of the fire vulnerability of the bridge.

The bridge current rating vulnerability indicator score is shown in table 14.

TABLE 14 bridge present rating score

In the step S2, the acquiring process of the bridge influence consequence value of the gas pipeline leakage fire is as follows: by the formula C₁＝C₁₁φ₁+C₁₂φ₂Obtaining the influence consequence value of the gas pipeline leakage fire on the bridge, wherein C₁Consequence value C for representing influence of gas pipeline leakage fire on bridge₁₁Denotes a loss value of life and property, phi₁Representing the weight of the loss of life and property, C₁₂Represents a traffic demand impact value and C₁₂＝C₃₁×ε₃₁+C₃₂×ε₃₂+C₃₃×ε₃₃，C₃₁Representing the influence of passenger-vehicle flow, C₃₂Score value, C, corresponding to distance to alternate route₃₃Representing the corresponding score value, epsilon, of the bridge service function_iIs a weight factor of the i-th index and epsilon₃₁，ε₃₂，ε₃₃Respectively 0.2, 0.4, phi₂Representing the weight taken by the traffic demand impact value.

Wherein the value of loss of life and property C₁₁The acquisition of (a) is as follows:

when a fire-jet accident occurs to a gas pipeline, people may be injured or even die. The influence of different heat radiation fluxes on the human body can be known from table 10. As can be seen from Table 10, 4.0KW/m²The heat radiation flux incident for more than 20s can cause pain, 9.5KW/m²Thermal radiation flux incident for 8s will cause the person to reach the pain limit and 20s will cause the person to burn second degree. Because the jet fire is an open fire, people around the fire can respond for a certain time to escape, and death accidents generally cannot occur. Therefore, the selection time is short and can cause a certain degree of influence on personnelInjured 9.5KW/m²As a thermal radiation flux threshold for personal injury. Estimate 9.5KW/m²The maximum number of injured people M can be calculated according to the maximum personnel density in the range corresponding to the thermal radiation flux.

The life and property loss correspondence score can be obtained from the following table:

TABLE 15 service life score

Traffic demand impact value C₁₂The acquisition of (a) is as follows:

the bridge is an important infrastructure in a traffic system, and once an accident occurs, the normal operation of the whole traffic network is influenced. The model researches the traffic demand of the bridge from three items of traffic flow, distance to a standby route and a bridge service function.

(1) Flow rate of people and vehicle C₃₁

And grading the pedestrian/traffic flow passing through the bridge according to the comprehensive consideration of the pedestrian/traffic flow of the affected bridge in one year to obtain the corresponding score. For a railroad bridge, default is 3 points.

Table 16 bridge pedestrian and vehicle flow corresponding fractional value table

Flow of people/vehicles	Corresponding score
		Chinese character shao (a Chinese character of 'shao')	1
Is less	3
		In general	5
Much more	7
		Multiple purpose	10

(2) Distance C to alternate route₃₂

When the gas pipeline is sprayed with fire to affect the bridge, the bridge cannot pass through vehicles or pedestrians, and other routes must be selected for going out at the moment, so that loss is caused by traffic delay. The distance to backup route score is given in the following table. For a railroad bridge, default is 3 points.

TABLE 17 distance to alternate route corresponding scores

Distance to backup route/m	Corresponding score
		＜500	1
500～1000	5
		＞1000	10

(3) Service function C₃₃

The values of the bridge service function score are as follows.

Table 18 bridge service function correspondence score

Bridge service function	Corresponding score
		Foot bridge	1
Motor vehicle passing bridge	5
		Motor vehicle axle with sidewalk	7
Railway bridge	10

Referring to tables 16 through 18, the traffic demand score can be calculated by: c₁₂＝C₃₁×ε₃₁+C₃₂×ε₃₂+C₃₃×ε₃₃。

Step S3: acquiring a second evaluation parameter of the bridge influenced by the underground space explosion, wherein the second evaluation parameter comprises an explosion damage possibility judgment coefficient, a score value of bridge explosion vulnerability and a result value of the bridge influenced by the underground space explosion;

the process of acquiring the explosion damage possibility judgment coefficient in step S3 is as follows:

the main failure mechanism of underground space (generally, drainage pipeline, and the drainage pipeline is used to replace underground space in the following) explosion to bridge is overpressure injury. It is therefore first determined whether an explosion of the drain line can occur and whether overpressure damage can be caused. According to the existing research experiment, the maximum value Rmax of the gas diffusion distance always exists, the research result of the German Water and gas Association (DVGW) considers that the Rmax is 12.5m, when the shortest distance between a gas pipeline and a water drainage pipeline is smaller than the Rmax, the first judgment coefficient lambda 21 is 1, otherwise the first judgment coefficient is 0.1, the water drainage pipeline has a safe buried depth, if the actual buried depth of the water drainage pipeline is larger than the safe buried depth, overpressure damage cannot be caused to a ground disaster bearing body, the second judgment coefficient lambda 22 is 0.1, otherwise, overpressure damage can be caused to the ground disaster bearing body, the second judgment coefficient lambda 22 is 1, the explosion damage possibility judgment coefficient lambda 2 is equal to the product of the first judgment coefficient lambda 21 and the second judgment coefficient lambda 22, and when the explosion damage possibility judgment coefficient lambda 2 is 1, the hidden danger of bridge damage caused by gas pipeline leakage underground space aggregation explosion is considered to exist;

wherein, the safe burial depth calculation process is as follows:

by the formula

Obtaining a relation between the safe buried depth and the equivalent diameter, wherein H_safeFor safe burial depth D_eIs an equivalent diameter and

S₀is the sectional area of the pipeline, and C is the circumference of the pipeline;

for a connecting line with a circular cross-section, S₀＝0.785D²And D represents the pipe diameter;

for connecting lines of approximately rectangular cross-section, S₀W denotes the rectangular cross-section line width, and H denotes the rectangular cross-section line height.

And the score value V of the bridge explosion vulnerability in the step S3₂The acquisition process comprises the following steps:

the bridge explosive vulnerability is evaluated according to the following table.

TABLE 19 bridge explosion vulnerability score

The result value C of the influence of the underground space explosion on the bridge in the step S3₂The influence of the explosion in the underground space on the bridge is mainly the traffic influence, and the influence of the explosion in the underground space on the bridge is consistent with the influence of the fire on the bridge traffic, so the details are not repeated herein.

Step S4: acquiring an emergency rescue factor; the specific process is as follows:

the gas company, the government and the emergency service department in the same city are not greatly different. Under the condition that the emergency rescue force is relatively abundant, the emergency system is complete, and the quality of emergency personnel is strong, the emergency rescue capacity can be represented by the time of the emergency rescue vehicle arriving at the scene and the accident recovery capacity.

The emergency response capability of engineering rescue team (beta 1) and fire fighting (beta 2) is represented by the distance between a gas pipeline to be evaluated and the nearest gas emergency maintenance station, emergency rescue unit, second-level and above medical institutions. Take the unit emergency repair capability of gas as an example, by formula

Obtaining the emergency capacity value of an engineering emergency team, wherein beta₁Representing the emergency capacity value of the engineering rescue team,

the seventh weight coefficient is expressed, and is inversely related to the traffic jam condition of the city, namely the more serious the traffic jam of the city is,

the smaller. d_iThe distance between the emergency disposal unit and the to-be-evaluated gas pipe section is represented, and m represents a correction coefficient; beta is a₂Calculation method and beta₁The same is true.

By the formula β ═ β₁v₁+β₂v₂Obtaining an emergency rescue factor, wherein beta represents the emergency rescue factor, v₁Representing the weight corresponding to the emergency capacity value of the engineering rescue team and taking the value of 0.6, beta₂Indicating the value of fire emergency capability, v₂And the weight corresponding to the fire emergency capacity value is represented and the value is 0.4.

Step S5: and calculating the risk level according to the gas pipeline leakage possibility score, a first evaluation parameter of the bridge fire caused by gas leakage, a second evaluation parameter of the bridge influenced by underground space explosion and an emergency rescue factor. The specific process is as follows:

by the formula

Acquiring a risk value of the fire to the bridge, wherein xi₁₁、ξ₁₂、σ₁₁、σ₁₂、σ₁₃The weights are respectively 0.9, 0.1, 0.3 and 0.4;

by the formula

Acquiring a risk value of explosion to the bridge, wherein xi₂₁、ξ₂₂、σ₁₁、σ₁₂、σ₁₃The weights are respectively 0.1, 0.9, 0.3 and 0.4;

by the formula R ═ R₁κ₁+R₂κ₂Obtaining a pipeline-bridge coupling risk value, wherein k₁Representing the weight of the fire on the risk value of the bridge, and taking the value as 0.6; kappa₂The weight of the risk value of the explosion to the bridge is represented, and the value is 0.4.

Converting the risk value into a percentile system, and classifying the pipeline-bridge coupling risk value grades: r is more than or equal to 0 and less than 40 and is divided into four grades, R is more than or equal to 40 and less than 60 and is divided into three grades, R is more than or equal to 60 and less than 80 and is divided into one grade, and R is more than or equal to 80 and less than 100 and is divided into one grade.

Through the technical scheme, the method for identifying and evaluating the coupling hidden danger of the gas pipeline and the bridge, provided by the invention, is used for establishing a method for identifying and evaluating the coupling hidden danger of the gas pipeline and the bridge, and evaluating the coupling risk of the gas pipeline and the bridge in three aspects of the possibility of leakage of the gas pipeline, the vulnerability of the bridge caused by the gas leakage to fire/explosion and the consequences caused by the fire/explosion.

Example 2

The invention also provides a device for identifying and evaluating the coupling hidden danger of the gas pipeline and the bridge, which comprises:

the gas pipeline leakage possibility score acquisition module is used for acquiring a gas pipeline leakage possibility score, wherein the gas pipeline leakage possibility score comprises a pipeline large leakage possibility score and a pipeline tiny leakage possibility score;

the second acquisition module is used for acquiring first evaluation parameters of the bridge fire caused by gas leakage, wherein the first evaluation parameters comprise a fire damage possibility judgment coefficient, a bridge fire vulnerability score value and a bridge influence consequence value of the gas pipeline leakage fire to the bridge;

the third acquisition module is used for acquiring a second evaluation parameter of the bridge influenced by the underground space explosion, wherein the second evaluation parameter comprises an explosion damage possibility judgment coefficient, a bridge explosion vulnerability score value and an influence result value of the underground space explosion on the bridge;

the fourth acquisition module is used for acquiring emergency rescue factors;

and the risk evaluation module is used for calculating the risk level according to the gas pipeline leakage possibility score, the first evaluation parameter of the bridge fire caused by gas leakage, the second evaluation parameter of the bridge influenced by underground space explosion and the emergency rescue factor.

Specifically, the process of acquiring the score of the possibility of a large number of leaks in the pipeline in the first acquiring module is as follows:

by the formula

Obtaining a leakage frequency based on pipeline information, wherein P_GIndicating the leakage frequency, P, based on pipeline information_diIndicating the leakage frequency, P, of a pipe section of diameter di_fiIndicating a leakage frequency, P, of fi, which is the pipe segment covering depth_hiIndicating the leakage frequency, P, of the pipe section wall thickness hi_dmaxRepresenting the maximum leakage frequency, P, of pipe sections of different diameters_fmaxIndicating different covers of a pipe sectionMaximum leakage frequency, P, at cap depth_hmaxIndicating the maximum leakage frequency, mu, at different pipe wall thicknesses of the pipe section₁Indicating a correction factor, mu, for the type of material of the pipe₂Indicates the construction activity degree and mu₂＝μ₂₁*w₁+μ₂₂*w₂，μ₂₁Represents the distance, w, of the construction site from the gas pipeline to be evaluated₁Represents the first weight and has a value of 0.6, mu₂₂Indicating construction controllability correction factor, w₂Represents a second weight and has a value of 0.4;

by the formula

Obtaining a third party breach leak frequency final score based on pipeline information, wherein Q₁₁Represents the third party corruption leakage frequency final score, min (P)_G) Represents the minimum value of the whole-market gas pipe section, max (P)_G) The maximum value of the term of the fuel gas pipe section of the whole city is shown;

by the formula Q₁＝Q₁₁α₁+Q₁₂α₂Obtaining a score of the likelihood of a large leak in the pipe, wherein Q₁Represents a pipeline high leak probability score, Q₁₂Representing the final score value, alpha, of the probability of a leak due to a geological disaster₁The weight which represents the large amount of leakage caused by the third-party construction is 0.8; alpha is alpha₂The weight of the large leakage caused by geological disaster is 0.2.

Specifically, the process of acquiring the score of the tiny leakage possibility of the pipeline in the first acquiring module is as follows:

by the formula Q₂＝Q₂₁α₃+Q₂₂α₄Obtaining a score of the possibility of a micro-leak in the pipe, wherein Q₂Indicates a score of a possible minute leakage of the pipe, Q₂₁Indicates the corrosion score, α₃Represents a weight of a small leakage caused by corrosion and has a value of 0.5, Q₂₂Indicates the material defect score, alpha₄Indicating that the material defect caused a minor leakage weight and has a value of 0.5.

Specifically, the acquiring process of the fire damage possibility judgment coefficient in the second acquiring module is as follows:

calculating the thermal radiation flux of the bridge caused by gas pipeline leakage by adopting a jet fire model, and taking 12.5KW/m²As a bridge thermal radiation flux threshold, when the calculated thermal radiation flux borne by the bridge exceeds the bridge thermal radiation flux threshold, the fire damage possibility judgment coefficient lambda is obtained₁Is 1, otherwise is 0.1, and when the possibility of fire damage is judged, the coefficient lambda is₁When the value is 1, the hidden danger that the bridge is damaged due to gas pipeline leakage exists, wherein the injection fire model is an API521 model or a THORNTON model.

Specifically, the process of acquiring the score value of the fire vulnerability of the bridge in the second acquisition module is as follows:

by the formula V₁＝V₁₁ψ₁₁+V₁₂ψ₁₂+V₁₃ψ₁₃+V₁₄ψ₁₄Obtaining a fire vulnerability score value of the bridge, wherein V₁Represents the value of the vulnerability of the bridge to fire, V₁₁Indicating the vulnerability score, psi, caused by the material type₁₁Represents a third weight and takes 0.3, V₁₂Indicating the vulnerability score, psi, caused by the structural member₁₂Represents a fourth weight and takes 0.2, V₁₃Indicating the vulnerability score, psi, due to age₁₃Represents a fifth weight and takes 0.2, V₁₄Indicates the vulnerability score, psi, resulting from the current rating₁₄Represents the sixth weight and takes 0.3.

Specifically, the process for acquiring the influence consequence value of the gas pipeline leakage fire on the bridge in the second acquisition module is as follows: by the formula C₁＝C₁₁φ₁+C₁₂φ₂Obtaining the influence consequence value of the gas pipeline leakage fire on the bridge, wherein C₁Value representing the consequences of a gas pipeline leakage fire on the bridge, C₁₁Indicating a value of life and property loss, phi₁Representing the weight of the loss of life and property, C₁₂Represents a traffic demand impact value and C₁₂＝C₃₁×ε₃₁+C₃₂×ε₃₂+C₃₃×ε₃₃，C₃₁Representing the influence of passenger-vehicle flow, C₃₂Score value, C, corresponding to distance to alternate route₃₃Representing the corresponding score value, epsilon, of the bridge service function_iIs a weight factor of the i-th index and epsilon₃₁，ε₃₂，ε₃₃Respectively 0.2, 0.4, phi₂Representing the weight taken by the traffic demand impact value.

Specifically, the process of acquiring the explosion damage possibility judgment coefficient in the third acquiring module is as follows:

when the shortest distance between the gas pipeline and the water drainage pipeline is smaller than Rmax, a first judgment coefficient lambda 21 is equal to 1, otherwise, the distance is 0.1, the water drainage pipeline has a safe burial depth, if the actual burial depth of the water drainage pipeline is larger than the safe burial depth, overpressure damage cannot be caused to a ground disaster bearing body, a second judgment coefficient lambda 22 is equal to 0.1, otherwise, overpressure damage can be caused to the ground disaster bearing body, the second judgment coefficient lambda 22 is equal to 1, an explosion damage possibility judgment coefficient lambda 2 is equal to the product of the first judgment coefficient lambda 21 and the second judgment coefficient lambda 22, and when the explosion damage possibility judgment coefficient lambda 2 is 1, bridge damage hidden danger caused by gas pipeline leakage underground space aggregation explosion is considered to exist;

wherein, the safe burial depth calculation process is as follows:

by the formula

Obtaining a relation between the safe buried depth and the equivalent diameter, wherein H_safeFor safe burial depth D_eIs an equivalent diameter and

S₀is the sectional area of the pipeline, and C is the circumference of the pipeline;

for a connecting line with a circular cross-section, S₀＝0.785D²And D represents the pipe diameter;

for connecting lines of approximately rectangular cross-section, S₀W denotes the rectangular cross-section line width, and H denotes the rectangular cross-section line height.

Specifically, the fourth obtaining module includes:

by the formula

Obtaining the emergency capacity value of an engineering emergency team, wherein beta₁Representing the emergency capacity value of the engineering rescue team,

denotes a seventh weight coefficient, d_iThe distance between the emergency disposal unit and the to-be-evaluated gas pipe section is represented, and m represents a correction coefficient;

by the formula β ═ β₁v₁+β₂v₂Obtaining an emergency rescue factor, wherein beta represents the emergency rescue factor, v₁Representing the weight corresponding to the emergency capacity value of the engineering rescue team and taking the value of 0.6, beta₂Indicating the value of fire emergency capability, v₂And the weight corresponding to the fire emergency capacity value is represented and the value is 0.4.

Specifically, the risk assessment module includes:

by the formula

Acquiring a risk value of the fire to the bridge, wherein xi₁₁、ξ₁₂、σ₁₁、σ₁₂、σ₁₃The weights are respectively 0.9, 0.1, 0.3 and 0.4;

by the formula

Acquiring a risk value of explosion to the bridge, wherein xi₂₁、ξ₂₂、σ₁₁、σ₁₂、σ₁₃The weights are respectively 0.1, 0.9, 0.3 and 0.4;

by the formula R ═ R₁κ₁+R₂κ₂Obtaining a pipeline-bridge coupling risk value, wherein k₁Representing the weight of the fire on the risk value of the bridge, and taking the value as 0.6; kappa₂The weight of the risk value of the explosion to the bridge is represented, and the value is 0.4.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (7)

1. A method for identifying and evaluating a gas pipeline-bridge coupling hidden danger is characterized by comprising the following steps:

the method comprises the following steps: acquiring a gas pipeline leakage possibility score, wherein the gas pipeline leakage possibility score comprises a pipeline large leakage possibility score and a pipeline tiny leakage possibility score;

step two: acquiring first evaluation parameters of bridge fire caused by gas leakage, wherein the first evaluation parameters comprise a fire damage possibility judgment coefficient, a bridge fire vulnerability score value and a bridge influence consequence value of gas pipeline leakage fire to the bridge;

the acquisition process of the bridge fire vulnerability score value is as follows:

by the formula V₁＝V₁₁ψ₁₁+V₁₂ψ₁₂+V₁₃ψ₁₃+V₁₄ψ₁₄Obtaining a fire vulnerability score value of the bridge, wherein V₁Represents the value of the vulnerability of the bridge to fire, V₁₁Indicating the vulnerability score, psi, caused by the material type₁₁Represents a third weight and takes 0.3, V₁₂Indicating the vulnerability score, psi, caused by the structural member₁₂Represents a fourth weight and takes 0.2, V₁₃Indicating the vulnerability score, psi, due to age₁₃Represents a fifth weight and takes 0.2, V₁₄Indicates the vulnerability score, psi, resulting from the current rating₁₄Represents a sixth weight and takes 0.3;

the acquisition process of the influence consequence value of the gas pipeline leakage fire on the bridge is as follows: by the formula C₁＝C₁₁φ₁+C₁₂φ₂Obtaining the influence consequence value of the gas pipeline leakage fire on the bridge, wherein C₁Value representing the consequences of a gas pipeline leakage fire on the bridge, C₁₁Indicating a value of life and property loss, phi₁Representing the weight of the loss of life and property, C₁₂Represents a traffic demand impact value and C₁₂＝C₃₁×ε₃₁+C₃₂×ε₃₂+C₃₃×ε₃₃，C₃₁Representing the influence of passenger-vehicle flow, C₃₂Score value, C, corresponding to distance to alternate route₃₃Representing the corresponding score value, epsilon, of the bridge service function_iIs a weight factor of the i-th index and epsilon₃₁，ε₃₂，ε₃₃Respectively 0.2, 0.4, phi₂Representing the weight occupied by the traffic demand influence value;

step three: acquiring a second evaluation parameter of the bridge influenced by the underground space explosion, wherein the second evaluation parameter comprises an explosion damage possibility judgment coefficient, a score value of bridge explosion vulnerability and a result value of the bridge influenced by the underground space explosion;

the acquisition process of the explosion damage possibility judgment coefficient comprises the following steps:

when the shortest distance between the gas pipeline and the water drainage pipeline is smaller than Rmax, a first judgment coefficient lambda 21 is equal to 1, otherwise, the distance is 0.1, the water drainage pipeline has a safe burial depth, if the actual burial depth of the water drainage pipeline is larger than the safe burial depth, overpressure damage cannot be caused to a ground disaster bearing body, a second judgment coefficient lambda 22 is equal to 0.1, otherwise, overpressure damage can be caused to the ground disaster bearing body, the second judgment coefficient lambda 22 is equal to 1, an explosion damage possibility judgment coefficient lambda 2 is equal to the product of the first judgment coefficient lambda 21 and the second judgment coefficient lambda 22, and when the explosion damage possibility judgment coefficient lambda 2 is 1, bridge damage hidden danger caused by gas pipeline leakage underground space aggregation explosion is considered to exist;

wherein, the safe burial depth calculation process is as follows:

by the formula

Obtaining a relation between the safe buried depth and the equivalent diameter, wherein H_safeIs to be anFull depth of burial, D_eIs an equivalent diameter and

S₀is the sectional area of the pipeline, and C is the circumference of the pipeline;

for a connecting line with a circular cross-section, S₀＝0.785D²And D represents the pipe diameter;

for connecting lines of approximately rectangular cross-section, S₀W represents the rectangular cross-section line width and H represents the rectangular cross-section line height;

step four: acquiring an emergency rescue factor;

step five: and calculating the risk level according to the gas pipeline leakage possibility score, a first evaluation parameter of the bridge fire caused by gas leakage, a second evaluation parameter of the bridge influenced by underground space explosion and an emergency rescue factor.

2. The method for identifying and evaluating the coupling hidden danger of the gas pipeline and the bridge as claimed in claim 1, wherein the process of obtaining the score of the possibility of the large amount of leakage of the pipeline in the step one is as follows:

by the formula

Obtaining a leakage frequency based on pipeline information, wherein P_GIndicating the leakage frequency, P, based on pipeline information_diIndicating the leakage frequency, P, of a pipe section of diameter di_fiIndicating a leakage frequency, P, of fi, which is the pipe segment covering depth_hiIndicating the leakage frequency, P, of the pipe section wall thickness hi_dmaxRepresenting the maximum leakage frequency, P, of pipe sections of different diameters_fmaxRepresenting the maximum leakage frequency, P, at different coating depths of the pipe section_hmaxIndicating the maximum leakage frequency, mu, at different pipe wall thicknesses of the pipe section₁Indicating a correction factor, mu, for the type of material of the pipe₂Indicates the construction activity degree and mu₂＝μ₂₁*w₁+μ₂₂*w₂，μ₂₁Gas pipeline to be evaluated for representing construction site distanceDistance, w₁Represents the first weight and has a value of 0.6, mu₂₂Indicating construction controllability correction factor, w₂Represents a second weight and has a value of 0.4;

by the formula

Obtaining a third party breach leak frequency final score based on pipeline information, wherein Q₁₁Represents the third party corruption leakage frequency final score, min (P)_G) Represents the minimum value of the whole-market gas pipe section, max (P)_G) The maximum value of the term of the fuel gas pipe section of the whole city is shown;

by the formula Q₁＝Q₁₁α₁+Q₁₂α₂Obtaining a score of the likelihood of a large leak in the pipe, wherein Q₁Represents a pipeline high leak probability score, Q₁₂Representing the final score value, alpha, of the probability of a leak due to a geological disaster₁The weight which represents the large amount of leakage caused by the third-party construction is 0.8; alpha is alpha₂The weight of the large leakage caused by geological disaster is 0.2.

3. The method for identifying and evaluating the coupling hidden danger of the gas pipeline and the bridge as claimed in claim 2, wherein the process of obtaining the score of the possibility of the small leakage of the pipeline in the first step is as follows:

by the formula Q₂＝Q₂₁α₃+Q₂₂α₄Obtaining a score of the possibility of a micro-leak in the pipe, wherein Q₂Indicates a score of a possible minute leakage of the pipe, Q₂₁Indicates the corrosion score, α₃Represents a weight of a small leakage caused by corrosion and has a value of 0.5, Q₂₂Indicates the material defect score, alpha₄Indicating that the material defect caused a minor leakage weight and has a value of 0.5.

4. The method for identifying and evaluating the coupling hidden danger of the gas pipeline and the bridge as claimed in claim 3, wherein the acquiring process of the fire damage possibility judgment coefficient in the second step is as follows:

calculating the thermal radiation flux of the bridge caused by gas pipeline leakage by adopting a jet fire model, and taking 12.5KW/m²As a bridge thermal radiation flux threshold, when the calculated thermal radiation flux borne by the bridge exceeds the bridge thermal radiation flux threshold, the fire damage possibility judgment coefficient lambda is obtained₁Is 1, otherwise is 0.1, and when the possibility of fire damage is judged, the coefficient lambda is₁When the value is 1, the hidden danger that the bridge is damaged due to gas pipeline leakage exists, wherein the injection fire model is an API521 model or a THORNTON model.

5. The method for identifying and evaluating the coupling hidden danger of the gas pipeline and the bridge as claimed in claim 4, wherein the fourth step comprises:

by the formula

Obtaining the emergency capacity value of an engineering emergency team, wherein beta₁Representing the emergency capacity value of the engineering rescue team,

denotes a seventh weight coefficient, d_iThe distance between the emergency disposal unit and the to-be-evaluated gas pipe section is represented, and m represents a correction coefficient;

by the formula β ═ β₁v₁+β₂v₂Obtaining an emergency rescue factor, wherein beta represents the emergency rescue factor, v₁Representing the weight corresponding to the emergency capacity value of the engineering rescue team and taking the value of 0.6, beta₂Indicating the value of fire emergency capability, v₂And the weight corresponding to the fire emergency capacity value is represented and the value is 0.4.

6. The method for identifying and evaluating the coupling hidden danger of the gas pipeline and the bridge as claimed in claim 5, wherein the step five comprises:

by the formula

Acquiring a risk value of the fire to the bridge, wherein xi₁₁、ξ₁₂、σ₁₁、σ₁₂、σ₁₃The weights are respectively 0.9, 0.1, 0.3 and 0.4;

by the formula

Acquiring a risk value of explosion to the bridge, wherein xi₂₁、ξ₂₂、σ₁₁、σ₁₂、σ₁₃The weights are respectively 0.1, 0.9, 0.3 and 0.4;

by the formula R ═ R₁κ₁+R₂κ₂Obtaining a pipeline-bridge coupling risk value, wherein k₁Representing the weight of the fire on the risk value of the bridge, and taking the value as 0.6; kappa₂The weight of the risk value of the explosion to the bridge is represented, and the value is 0.4.

7. An apparatus for identifying and evaluating a gas pipeline-bridge coupling hidden danger, the apparatus comprising:

the gas pipeline leakage possibility score acquisition module is used for acquiring a gas pipeline leakage possibility score, wherein the gas pipeline leakage possibility score comprises a pipeline large leakage possibility score and a pipeline tiny leakage possibility score;

the second acquisition module is used for acquiring first evaluation parameters of the bridge fire caused by gas leakage, wherein the first evaluation parameters comprise a fire damage possibility judgment coefficient, a bridge fire vulnerability score value and a bridge influence consequence value of the gas pipeline leakage fire to the bridge;

the acquisition process of the bridge fire vulnerability score value is as follows:

by the formula V₁＝V₁₁ψ₁₁+V₁₂ψ₁₂+V₁₃ψ₁₃+V₁₄ψ₁₄Obtaining a fire vulnerability score value of the bridge, wherein V₁Represents the value of the vulnerability of the bridge to fire, V₁₁Indicating the vulnerability score, psi, caused by the material type₁₁Represents a third weight and takes 0.3, V₁₂Indicating the vulnerability score, psi, caused by the structural member₁₂Represents a fourth weight and takes 0.2, V₁₃Indicating the vulnerability score, psi, due to age₁₃Represents a fifth weight and takes 0.2, V₁₄Indicates the vulnerability score, psi, resulting from the current rating₁₄Represents a sixth weight and takes 0.3;

the acquisition process of the influence consequence value of the gas pipeline leakage fire on the bridge is as follows: by the formula C₁＝C₁₁φ₁+C₁₂φ₂Obtaining the influence consequence value of the gas pipeline leakage fire on the bridge, wherein C₁Value representing the consequences of a gas pipeline leakage fire on the bridge, C₁₁Indicating a value of life and property loss, phi₁Representing the weight of the loss of life and property, C₁₂Represents a traffic demand impact value and C₁₂＝C₃₁×ε₃₁+C₃₂×ε₃₂+C₃₃×ε₃₃，C₃₁Representing the influence of passenger-vehicle flow, C₃₂Score value, C, corresponding to distance to alternate route₃₃Representing the corresponding score value, epsilon, of the bridge service function_iIs a weight factor of the i-th index and epsilon₃₁，ε₃₂，ε₃₃Respectively 0.2, 0.4, phi₂Representing the weight occupied by the traffic demand influence value;

the third acquisition module is used for acquiring a second evaluation parameter of the bridge influenced by the underground space explosion, wherein the second evaluation parameter comprises an explosion damage possibility judgment coefficient, a bridge explosion vulnerability score value and an influence result value of the underground space explosion on the bridge;

the acquisition process of the explosion damage possibility judgment coefficient comprises the following steps:

when the shortest distance between the gas pipeline and the water drainage pipeline is smaller than Rmax, a first judgment coefficient lambda 21 is equal to 1, otherwise, the distance is 0.1, the water drainage pipeline has a safe burial depth, if the actual burial depth of the water drainage pipeline is larger than the safe burial depth, overpressure damage cannot be caused to a ground disaster bearing body, a second judgment coefficient lambda 22 is equal to 0.1, otherwise, overpressure damage can be caused to the ground disaster bearing body, the second judgment coefficient lambda 22 is equal to 1, an explosion damage possibility judgment coefficient lambda 2 is equal to the product of the first judgment coefficient lambda 21 and the second judgment coefficient lambda 22, and when the explosion damage possibility judgment coefficient lambda 2 is 1, bridge damage hidden danger caused by gas pipeline leakage underground space aggregation explosion is considered to exist;

wherein, the safe burial depth calculation process is as follows:

by the formula

Obtaining a relation between the safe buried depth and the equivalent diameter, wherein H_safeFor safe burial depth D_eIs an equivalent diameter and

S₀is the sectional area of the pipeline, and C is the circumference of the pipeline;

for a connecting line with a circular cross-section, S₀＝0.785D²And D represents the pipe diameter;

for connecting lines of approximately rectangular cross-section, S₀W represents the rectangular cross-section line width and H represents the rectangular cross-section line height;

the fourth acquisition module is used for acquiring emergency rescue factors;

and the risk evaluation module is used for calculating the risk level according to the gas pipeline leakage possibility score, the first evaluation parameter of the bridge fire caused by gas leakage, the second evaluation parameter of the bridge influenced by underground space explosion and the emergency rescue factor.

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