A risk assessment method for the whole life cycle of tunnel facilities

Abstract

The present invention relates to the technical field of tunnel operation risk assessment, and specifically to a method for risk assessment of tunnel facilities throughout their life cycle, comprising the following steps: 1) clarifying the conduction law of tunnel facility risks during their life cycle, and calculating the initial residual value of facility risks; 2) determining the presence state of a risk stimulating environment for tunnel facilities, and determining the presence strength of the stimulating environment; 3) obtaining a risk transmission capacity coefficient value based on the initial residual value of facility risks and the presence strength of the risk stimulating environment; compared with the prior art, the present invention has the following beneficial effects: through a tunnel chain safety risk assessment method for the entire life cycle of tunnel facilities, the ability of tunnel facility risks from generation to conduction development and risk control is comprehensively considered, and through the description of the presence state of the risk stimulating environment and the analysis of the safety risk prevention and control capabilities of tunnel facilities.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel operation risk assessment, and in particular to a method for risk assessment of tunnel facilities throughout their life cycle. Background Art

[0002] In tunnel engineering, conducting safety risk assessment of in-service tunnels is a key measure to ensure tunnel operation. As a man-made structure, the safety risk of tunnel facilities during their service life is not only related to the maintenance status during the operation period, but also to the defects and risks left over during the design and construction period. These risks are stored and transmitted in various forms until they are induced, affecting the safe use of tunnel facilities. Existing research on safety risk assessment methods for in-service tunnels is mostly focused on the external diseases of tunnels during the operation period, but no attention is paid to the transmission mode of diseases at various stages of the tunnel life and the existence state of the risk-stimulating environment, which leads to the transmission of some risk factors during the tunnel life cycle, but they are not considered in tunnel safety assurance, and these factors will have an impact on the safety of tunnel facilities.

[0003] In the early stage of tunnel construction, some hidden dangers that have not affected the tunnel construction will further expand with the passage of time and the existence of a risk environment, until the safety of tunnel facilities is damaged. The maintenance of existing tunnel facilities can only be carried out after the safety impact becomes apparent, which has a certain lag, and it is impossible to understand the hidden danger detection and development status from the early stage, which affects the safe use of tunnel facilities.

[0004] Therefore, developing a risk assessment method for the entire life cycle of tunnel facilities not only has urgent research value, but also has good economic benefits and industrial application potential, which is the driving force and basis for the completion of the present invention. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the prior art, the inventors conducted in-depth research and completed the present invention after paying a lot of creative work.

[0006] Specifically, the technical problem to be solved by the present invention is to evaluate the safety risk transfer capability of tunnel facilities during their life cycle and the impact of risk factors after periodic transfer on the installation of tunnel facilities.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for risk assessment of the whole life cycle of tunnel facilities comprises the following steps:

[0009] 1) Clarify the transmission rules of tunnel facility risks during the life cycle and calculate the initial residual value of facility risks;

[0010] 2) Obtain the state of the risk-stimulating environment of the tunnel facilities and determine the strength of the risk-stimulating environment;

[0011] 3) Obtain the risk transfer capacity coefficient value based on the initial residual value of the tunnel facility risk and the strength of the risk excitation environment;

[0012] 4) Calculate the maintenance health coefficient of tunnel facilities and obtain the risk prevention and control capabilities of tunnel facilities based on the health coefficient;

[0013] 5) Calculate the safety assessment value of tunnel facilities based on the risk prevention and control capability of tunnel facilities and the risk coefficient value;

[0014] 6) Coordinate various risk safety assessment values ​​to calculate the total safety risk assessment value of tunnel facilities, and assess the safety level of tunnel facilities based on the total safety risk assessment value.

[0015] In the present invention, as an improvement, the risk of tunnel facilities is chain-transmitted during the life cycle, specifically including: the risk occurs during the entire life cycle, remains from the previous time node and is transmitted to the next time node, and the entire life cycle refers to a tunnel facility risk assessment cycle based on an annual unit, in which multiple time nodes are divided.

[0016] In the present invention, as an improvement, the risks that tunnel facilities can transmit include the risk of tunnel lining collapse, the risk of tunnel sudden water inrush and the risk of tunnel portal section landslide.

[0017] In the present invention, as an improvement, the initial residual value of facility risk is calculated as follows:

[0018] The initial residual value of the risk of type i facility is F(i), which is expressed as:

[0019] F(i)=F / 2

[0020] Among them, F is the residual value of type i risk during the construction period of tunnel facilities after taking control measures, and the F value is taken from the tunnel facility safety risk level standard.

[0021] In the present invention, as an improvement, the state of the excitation environment is determined as follows:

[0022]

[0023] Among them, p is the frequency of occurrence of an environment that significantly increases or manifests type i risk; j is the time period used for security risk assessment.

[0024] In the present invention, as an improvement, the risk transfer capacity coefficient value R of type i risk and the initial residual value and environmental state occurrence state function relationship are as follows:

[0025] F(F(i),E(i),R)=0;

[0026] Among them, when E(i)≤1, R(i)=F(i); when E(i)>1, R(i)=F(i)E(i).

[0027] In the present invention, as an improvement, the health factor of tunnel facility maintenance is calculated as follows:

[0028]

[0029] Among them, γ j is the technical status value in period j, γ j-1 is the technical status value in the j-1 period, L γj is the scale length in period j, L γj-1 is the scale length within j-1 period.

[0030] In the present invention, as an improvement, the tunnel facility risk prevention and control capability g(i) is calculated as follows:

[0031] F(K,δ,g(i))=0

[0032] Among them, δ is the rate of inspection and rectification of hidden dangers of tunnel facilities in period j;

[0033] The safety assessment value of tunnel facilities is calculated as follows:

[0034]

[0035] In the present invention, as an improvement, the total assessment value of tunnel facility safety risk is calculated as follows:

[0036] A=min{A(1),A(2),....,A(i)}.

[0037] In the present invention, as an improvement, the tunnel facility safety level assessment includes:

[0038] When the tunnel facility safety assessment value is less than 0.5, the tunnel risk level is high risk;

[0039] When the tunnel facility safety assessment value is greater than or equal to 0.5 and less than or equal to 1, the tunnel risk level is high risk;

[0040] When the tunnel facility safety assessment value is greater than or equal to 1 and less than or equal to 2, the tunnel risk level is low risk;

[0041] When the tunnel facility safety assessment value is greater than 2, the tunnel risk level is low risk.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) The present invention is a safety assessment method for tunnel facilities. By evaluating the chain safety risks of the entire life cycle of tunnel facilities, the risk generation, transmission and development of tunnel facilities and the risk control capabilities are coordinated. By describing the state of the risk-inducing environment and analyzing the safety risk prevention and control capabilities of tunnel facilities, the safety risk status of in-service tunnels considering the entire life cycle can be judged, providing a clear basis for the structural safety of the tunnel.

[0044] (2) This application starts from the nature of the safety hazards of tunnel facilities, considers the safety hazards that have a low risk level in the early stage of tunnel construction but have a greater impact over time, evaluates various risk states, and classifies tunnel facility risks based on the evaluation results, so as to fully understand the risk level of tunnel facilities and provide a basis for subsequent response measures and monitoring plans. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0046] Figure 1 Schematic diagram of the evaluation method of the present invention. DETAILED DESCRIPTION

[0047] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0048] A method for risk assessment of the whole life cycle of tunnel facilities. Tunnel facilities have a long service life in the tunnel, and some safety hazards in the early stage of construction will remain and be transmitted over time. The transmission of risk factors depends on the chain transmission of risks at various stages in the life cycle of the facility, the state of the risk-inducing environment, and the risk prevention and control capabilities of the facility. This application evaluates the risk impact of the life cycle of tunnel facilities from three aspects, specifically including the following steps:

[0049] (1) Clarify the transmission rules of tunnel facility risks during their life cycle and calculate the initial residual value of facility risks;

[0050] During the life cycle, transferable risks to tunnel facilities include:

[0051] Risk of sudden water inrush caused by lining and geological structure;

[0052] The risk of lining collapse caused by the transmission of lining construction hazards during the risk cycle;

[0053] The risk of tunnel entrance landslide caused by hidden dangers in tunnel entrance design and construction and hydrogeological conditions.

[0054] Through the analysis of the risk transmission of tunnel facilities, the risk transmission characteristics of the facilities are chain transmission mode. A certain type of risk remains in the previous cycle and is transmitted to the next cycle. The initial residual value of the risk is calculated as follows:

[0055] F(i)=F / 2

[0056] Among them, F(i) is the initial residual value of the risk of a certain type i facility, and F is the residual value of the type i risk during the construction period of the tunnel facility after taking control measures. The F value is selected according to the current safety risk level requirements for highway bridge and tunnel engineering design. Among them, when the tunnel safety risk level is level three, control measures need to be taken to eliminate the risk. Therefore, the maximum value of F is 2, and the value range of F(i) is between 0.5 and 1.

[0057] The risk transfer cycle is divided into years.

[0058] 2) Obtain the state of the risk-stimulating environment of the tunnel facility and determine the strength of the stimulating environment. The state of the risk-stimulating environment refers to the environmental state that can significantly increase the risk or make the risk appear. The environment that can stimulate the risk includes groundwater level changes, heavy precipitation, freeze-thaw, earthquakes and external construction disturbances. The functional relationship of the state of the risk-stimulating environment is as follows:

[0059]

[0060] Among them, p is the frequency of occurrence of an environment that significantly increases or manifests type i risk; j is the time period used for security risk assessment.

[0061] When E(i)<1, it indicates that the environmental factors that can trigger the occurrence of risks are becoming weaker and weaker; when E(i)>1, it indicates that the environmental factors that can trigger the occurrence of risks are becoming stronger and stronger.

[0062] 3) The risk transfer coefficient value is obtained based on the initial residual value of the facility risk and the occurrence strength of the risk excitation environment. Among them, the risk transfer capacity coefficient R(i) of type i is determined by the initial residual value F(i) and the occurrence state E(i) of the risk excitation environment, and there is the following functional relationship:

[0063] F(F(i),E(i),R(i))=0

[0064] Among them, when E(i)≤1, R(i)=F(i);

[0065] When E(i)>1, R(i)=F(i)E(i).

[0066] 4) Calculate the maintenance health coefficient of tunnel facilities and obtain the risk prevention and control capabilities of tunnel facilities based on the health coefficient;

[0067] The ability to prevent and control tunnel risks lies in identifying tunnel facility risks, avoiding the impact of risks on tunnel facilities, and reducing the risk-inducing environment through maintenance of tunnel facilities and inspection and rectification of safety hazards.

[0068] 5) Calculate the safety assessment value of the tunnel facility based on the risk prevention and control capability of the tunnel facility and the risk coefficient value.

[0069] 6) Coordinate various risk safety assessment values ​​to calculate the total safety risk assessment value of tunnel facilities, and assess the safety level of tunnel facilities based on the total safety risk assessment value.

[0070] The maintenance level of tunnel facilities is expressed by the health coefficient K. j and j-1 are two adjacent cycles. The health coefficient K is calculated as follows:

[0071]

[0072] Among them, γ j is the technical status value in period j, γ j-1 is the technical status value in the j-1 period, L γj is the scale length in period j, L γj-1 is the scale length within j-1 period;

[0073] γ is determined based on the technical condition of the tunnel facility in the tunnel facility construction standard, and the value range is 1-4.

[0074] When K=1, it means that the maintenance level of tunnel facilities remains stable; K>1 means that the maintenance level of tunnel facilities is improved and the health of tunnel structure is improved; K<1 means that the maintenance level of tunnel facilities is reduced and the health of tunnel structure is deteriorated.

[0075] The K value ranges from 0.25 to 4. Based on the analysis of previous engineering data, the tunnel health coefficient K in actual projects ranges from 0.5 to 1.5.

[0076] Among them, for the i-type risk with a technical status value of 4:

[0077] When L i4 =0, the tunnel maintenance level is good, K is [1,1.5], and the exponential relationship between g(i) and K is g(i)=K δ , at this time, the maximum value of g(i) is 1.5, and the value range is 1-1.27;

[0078] When L i4 When ≠0, the tunnel maintenance level is poor, K is [0.5, 1], and there is a product relationship g(i) = Kδ. At this time, the maximum value of g(i) is 1, and the value range is 0.3-0.6.

[0079] The completion rate of safety hazard inspection and rectification in period j is δ, and the prevention and control capability of tunnel facility type i risk is expressed as:

[0080] F(K,δ,g(i))=0

[0081] The safety assessment value A(i) of risk type i is calculated as follows:

[0082]

[0083] The total assessment value of tunnel facility safety risk is determined by the minimum value of each risk category:

[0084] A=min{A(1),A(2),....,A(i)}.

[0085] The risk level classification range is derived based on the technical specifications of tunnel facilities and the actual engineering database. When the tunnel facility safety assessment value is less than 0.5, the tunnel risk level is high risk; when the tunnel facility safety assessment value is greater than or equal to 0.5 and less than or equal to 1, the tunnel risk level is high risk; when the tunnel facility safety assessment value is greater than or equal to 1 and less than or equal to 2, the tunnel risk level is low risk; when the tunnel facility safety assessment value is greater than 2, the tunnel risk level is low risk.

[0086] Embodiment 1:

[0087] A highway tunnel put into operation in 2021 is 2,447 meters long. The tunnel section adopts a three-center circle section type, with a net width of 14.992 meters and a net height of 7.90 meters.

[0088] The tunnel site is a low mountain and hilly landform area with an annual minimum temperature of 3°C and relatively developed interlayer joints and fissures. No large-scale karst development or large caves were found during the survey, and only local dissolution grooves and small dissolution holes were found. The tunnel site belongs to the sedimentary rock fissure water aquifer, and the stable groundwater level is lower than the tunnel design elevation. According to statistics, the precipitation in the tunnel site is stable and there is no extreme weather. There were 8 days with a single precipitation intensity greater than 90 mm in 2021-2022, and 11 days with a single precipitation intensity greater than 90 mm in 2022-2023. No earthquakes occurred in the tunnel site during the operation period. From May to November 2022 and from March to April 2023, large equipment entered the construction site 1.5 kilometers away from the tunnel.

[0089] After the investigation of existing data, the residual risk level values ​​of civil facilities and electromechanical facilities after the completion of the tunnel are both 1. In the annual inspections conducted by the superior competent department, the implementation of risk assessment and hidden danger investigation in 2022 and 2023 reached 100%; the assessment results and scale length of tunnel facilities are shown in Table 1:

[0090] Table 1 Technical status assessment and scale of tunnel facilities in 2022 and 2023

[0091]

[0092]

[0093] A risk assessment of the tunnel is now conducted, including two types of risks: tunnel water inrush and lining collapse. Tunnel water inrush is defined as risk 1 and lining collapse is defined as risk 2.

[0094] The evaluation cycle is divided into years, j1 is 2021-2022, and j2 is 2022-2023.

[0095] Calculation of risk transfer capacity R:

[0096] ① Initial residual value of tunnel facility risk F(i)

[0097] F(i)=1 / 2=0.5

[0098] ② The endowment state of the risk-inducing environment E(i)

[0099] 1) Risk of sudden water inrush in tunnels

[0100]

[0101] 2) Tunnel lining collapse risk

[0102]

[0103] ③Risk transfer capability R

[0104] E(1)>1, R(1)=F(1)E(1)=0.5×1.375=0.6875

[0105] E(2)<1, R(2)=F(2)=0.5

[0106] (2) Calculation of risk prevention and control capability g(i):

[0107] ① Tunnel structure health effectiveness coefficient K

[0108] Substituting the data in Table 1, we can get:

[0109]

[0110] ② The completion rate of safety hazard investigation and rectification is 100%, and the value is 1

[0111] ③Risk prevention and control capabilities g(i)

[0112] L i4 = 0, g(i) = K δ=1.06(i=1,2)

[0113] (3) Chain safety risk assessment value A(i) for class i tunnel

[0114]

[0115] (4) The overall chain safety risk assessment value A of the tunnel takes the minimum value of A(i) 1.54. It can be seen from Table 2 that:

[0116] Table 2 Determination of tunnel risk level

[0117] The value range of A A<0.5 0.5≤A≤1 1≤A≤2 A>2 Tunnel risk level Significant risks Greater risk General Risks Low risk

[0118] The tunnel as a whole is in a general risk state, and corresponding technical measures can be taken according to the risk status in the future.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for risk assessment of the whole life cycle of tunnel facilities, characterized in that: The steps include: 1) Clarify the transmission rules of tunnel facility risks during the life cycle and calculate the initial residual value of facility risks; 2) Obtain the state of the risk-stimulating environment of the tunnel facilities and determine the strength of the risk-stimulating environment; 3) Obtain the risk transfer capacity coefficient value based on the initial residual value of the tunnel facility risk and the strength of the risk excitation environment; 4) Calculate the maintenance health coefficient of tunnel facilities and obtain the risk prevention and control capabilities of tunnel facilities based on the health coefficient; 5) Calculate the safety assessment value of tunnel facilities based on the risk prevention and control capability of tunnel facilities and the risk coefficient value; 6) Calculate the total safety risk assessment value of tunnel facilities by coordinating the safety assessment values ​​of various risks, and assess the safety level of tunnel facilities based on the total safety risk assessment value; The initial residual value of facility risk is calculated as follows: The initial residual value of the risk of type i facility is F(i), which is expressed as: F(i)=F / 2 Among them, F is the residual value of the i-type risk during the construction period of the tunnel facility after taking control measures. The F value is taken from the tunnel facility safety risk level standard; The state of the excitation environment is determined as follows: Among them, p is the frequency of occurrence of the environment that significantly increases or manifests the risk of type i; j is the time period used for security risk assessment; The functional relationship between the risk transfer coefficient value R of type i risk and the initial residual value and environmental state occurrence state is as follows: F(F(i),E(i),R)=0; Among them, when E(i)≤1, R(i)=F(i); when E(i)>1, R(i)=F(i)E(i).

2. The tunnel facility life cycle risk assessment method according to claim 1 is characterized in that: The risk of tunnel facilities is transmitted in a chain manner during the life cycle, specifically including: risks appear in the whole life cycle, remain from the previous time node and are transmitted to the next time node. The whole life cycle refers to a tunnel facility risk assessment cycle based on an annual unit, which is divided into multiple time nodes.

3. The tunnel facility life cycle risk assessment method according to claim 1 is characterized by: The transferable risks of tunnel facilities include the risk of tunnel lining collapse, the risk of tunnel sudden water inrush and the risk of tunnel portal landslide.

4. The tunnel facility life cycle risk assessment method according to claim 1 is characterized in that: The health factor of tunnel facility maintenance is calculated as follows: Among them, γ j is the technical status value in period j, γ j-1 is the technical status value in the j-1 period, L γj is the scale length in period j, L γj-1 is the scale length within j-1 period.

5. The tunnel facility life cycle risk assessment method according to claim 1 is characterized in that: The tunnel facility risk prevention and control capability g(i) is calculated as follows: F(K,δ,g(i))=0 Among them, δ is the rate of inspection and rectification of hidden dangers of tunnel facilities in period j; The safety assessment value of tunnel facilities is calculated as follows:

6. The tunnel facility life cycle risk assessment method according to claim 1 is characterized in that: The total safety risk assessment value of tunnel facilities is calculated as follows: A=min{A(1),A(2),....,A(i)}.

7. The tunnel facility life cycle risk assessment method according to claim 1 is characterized by: Tunnel facility safety level assessment includes: When the tunnel facility safety assessment value is less than 0.5, the tunnel risk level is high risk; When the tunnel facility safety assessment value is greater than or equal to 0.5 and less than or equal to 1, the tunnel risk level is high risk; When the tunnel facility safety assessment value is greater than or equal to 1 and less than or equal to 2, the tunnel risk level is low risk; When the tunnel facility safety assessment value is greater than 2, the tunnel risk level is low risk.

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