Buckling failure vulnerability analysis method for vertical storage tanks under coupled flood and hurricane conditions

Abstract

The present invention discloses a method for analyzing the vulnerability of a vertical storage tank to buckling failure under the coupling of flood and hurricane. The method comprises the following steps: determining the basic information of the vertical storage tank; determining the force acting on the vertical storage tank; calculating the resistance load of the vertical storage tank; calculating the external force acting on the vertical storage tank; establishing the limit state equation of the buckling failure of the storage tank under the coupling of flood and hurricane according to the judgment basis of the buckling failure of the storage tank; using the Monte Carlo simulation method to count the number of buckling failures of the target storage tank and calculate the failure probability; drawing the vulnerability curve of the storage tank under the coupling of flood and hurricane, and analyzing the influence of different wind speeds, water speeds, water depths and filling rates on the storage tank. The present invention can accurately calculate the buckling failure probability of the vertical storage tank under the coupling of flood and hurricane, and provide a strong basis for the vulnerability assessment of chemical process equipment under the coupling of multiple disasters.

Description

Technical Field

[0001] The invention relates to the field of vulnerability analysis of chemical process equipment, and in particular to a method for analyzing the buckling failure vulnerability of a vertical storage tank under the coupling effects of flood and hurricane. Background Art

[0002] Vertical storage tanks are an important part of industrial facilities and are widely used in the storage of various liquids such as crude oil and liquefied petroleum gas. With the rapid development of chemical parks, vertical storage tanks have been widely used. Due to convenient transportation and low economic cost, storage tanks are usually located in coastal areas, exposing them to natural disasters such as floods, hurricanes or waves, which leads to the leakage of a large number of harmful substances in chemical parks, resulting in catastrophic consequences. In coastal areas, hurricanes often cause floods, causing storage tanks to be coupled with floods and hurricanes at the same time. Therefore, conducting a vulnerability analysis of storage tank buckling failure under the coupling of floods and hurricanes has important engineering value for the construction of a multi-hazard coupling accident prevention and control system.

[0003] Currently, there are few analyses of vulnerability to flood and hurricane coupling, and most of them consider the vulnerability analysis methods of structures under the action of a single disaster. For example, an existing invention patent discloses a method for analyzing the vulnerability of concrete bridges to floods; an existing invention patent discloses a method for analyzing the vulnerability of transmission towers to wind disasters. The above methods propose a vulnerability analysis method for single loads such as floods or wind, but they cannot objectively reflect the safety performance of structures under the coupling of multiple disasters. Summary of the invention

[0004] The main technical problem solved by the present invention is the buckling failure vulnerability analysis problem of a vertical storage tank under the coupling effect of flood and hurricane.

[0005] In order to solve the above technical problems, the present invention provides a method for analyzing the buckling failure vulnerability of a vertical storage tank under the coupling action of flood and hurricane. The buckling failure probability of the storage tank under the coupling action of flood and hurricane can be calculated based on the basic parameters of the storage tank as well as the wind speed, flood speed and flood depth, thereby providing a strong basis for evaluating the safety performance of the storage tank under the coupling action of flood and hurricane.

[0006] The purpose of the present invention is achieved by at least one of the following technical solutions.

[0007] The buckling failure vulnerability analysis method of a vertical storage tank under the coupling of flood and hurricane includes the following steps:

[0008] S1. Determine the basic information of the vertical storage tank;

[0009] S2. Conduct a force analysis of the buckling failure of vertical storage tanks under the coupling of flood and hurricane to determine the forces acting on the vertical storage tanks;

[0010] S3. Calculate the resistance load of the vertical storage tank based on the basic information of the vertical storage tank;

[0011] S4. Determine the range and distribution of random parameters based on historical statistical accident data and calculate the external forces acting on the vertical storage tank;

[0012] S5. Based on the judgment basis of tank buckling failure, establish the limit state equation of tank buckling failure under the coupling of flood and hurricane;

[0013] S6. Use the Monte Carlo simulation method to count the number of buckling failures of the target tank and calculate the failure probability;

[0014] S7. Draw the vulnerability curve of the storage tank under the coupling of flood and hurricane, and analyze the impact of different wind speeds, water speeds, water depths and filling rates on the storage tank.

[0015] Furthermore, in step S1, the basic information of the vertical storage tank includes: the tank diameter D, the tank height H, the tank thickness t i , Young's modulus E, density of the medium in the tank ρ l and filling rate

[0016] Further, in step S2, the forces acting on the tank wall during buckling failure of the vertical storage tank under the coupling of flood and hurricane include the forces acting on the tank wall by wind load, flood load and wave load;

[0017] In the coupling of flood and hurricane, in addition to flood load and wind load, it also includes wave load caused by the interaction between flood and hurricane; wind load, flood load and wave load act on different parts of the tank wall, as follows:

[0018] Hurricanes, or wind loads, can create strong wind pressure on the top of the tank;

[0019] The hydrostatic and hydrodynamic pressures of the flood load act on the bottom of the tank and increase as the water level rises;

[0020] Hurricanes blowing over the water create waves, and storage tanks above the water level are subject to the forces of wave loads.

[0021] Furthermore, in step S3, the calculation formula for the tank load resistance is:

[0022]

[0023]

[0024] P r =P l +P cr

[0025] Among them, Pl P is the static pressure generated by the liquid in the tank; cr is the critical pressure of the tank; P r is the total resistance pressure of the tank; ρ l is the density of the liquid in the tank; is the tank filling rate; E is Young's modulus; g is the acceleration of gravity; t i is the tank wall thickness; D is the tank diameter; H is the tank height.

[0026] Further, in step S4, based on historical statistical accident data, the random parameters include wind speed, water speed, water depth and filling rate.

[0027] Furthermore, in step S4, the wind pressure of the wind load acting on the storage tank is specifically as follows:

[0028] P wind =C P (θ)P0

[0029]

[0030]

[0031]

[0032] q eq =k w P max

[0033]

[0034] Among them, C P (θ) is the wind pressure coefficient of the tank at different circumferential angles θ; θ is the circumferential angle; P0 is the reference wind pressure; ρ air V is the air density under standard atmospheric pressure; wind is wind speed; P max is the maximum wind pressure of non-uniform distribution; w0 is the length parameter of the tank wall, C θ is the external pressure buckling coefficient; q eq is the equivalent uniform wind pressure; k w is the equivalent wind pressure coefficient. According to European standard EN1993-1-6, k w The value range is [0.65,1];

[0035] The hydrostatic and hydrodynamic pressures of flood loads acting on the bottom of the tank are as follows:

[0036] P s =ρ w gh

[0037]

[0038] Among them, P s is the hydrostatic pressure; ρ w is the flood density; h is the depth of the flood inundating the storage tank; P d is the dynamic water pressure; C d is the resistance coefficient; V w is the flood velocity;

[0039] With the horizontal plane as the X-axis and the vertical direction perpendicular to the horizontal plane as the Z-axis, a rectangular coordinate system is established. The forces acting on the storage tank by the wave load are as follows:

[0040]

[0041]

[0042]

[0043] Among them, H w is the wave height; k is the wave number, w is the wave frequency, J′1(kd) is the derivative of the first-kind Bessel function, Y′1(kd) is the derivative of the second-kind Bessel function; d is the tank radius; f x (z) is the wave force per unit length in the Z direction; z is the independent variable; L is the wavelength; cosh(kh) is the hyperbolic cosine function with kh as the independent variable; δ is a constant, which is obtained by the formula;

[0044] The horizontal wave force F1 on the tank wall below the water surface is as follows:

[0045]

[0046] The horizontal wave force F2 on the tank wall above the water surface is as follows:

[0047]

[0048] Among them, H s is the vertical distance from the wave crest to the horizontal plane;

[0049] The calculation formula of wave elements is as follows:

[0050]

[0051]

[0052]

[0053] Where T is the wave period; m is the length of the wind zone.

[0054] Furthermore, the calculation formula of the external force on the storage tank under the coupling of flood and hurricane is:

[0055]

[0056] Where P is the maximum external force acting on the tank; t is time.

[0057] Furthermore, in step S5, the strong pressure generated by floods and hurricanes may cause the tank wall to buckle and fail, that is, when the external force acting on the tank wall is greater than the resistance pressure of the tank, the tank buckles and fails;

[0058] The limit state equation of the buckling failure of the storage tank under the coupling of flood and hurricane is:

[0059] Z=PP r =PP cr -P l

[0060] Among them, Z is the limit state function. When Z>0, the tank fails due to buckling.

[0061] Furthermore, in step S6, the Monte Carlo simulation method is used to count the number of buckling failures of the target tank and calculate the failure probability, which is as follows:

[0062] Solve the resistance load of the storage tank;

[0063] The external force on the tank wall is calculated and substituted into the limit state equation to determine whether the tank fails due to buckling.

[0064] Write a Monte Carlo calculation program, taking into account the calculation accuracy and running time, and take the number of sampling cycles as 10 6 times, calculate the failure probability.

[0065] Furthermore, in step S7, the Monte Carlo method is used to sample random parameters, calculate the buckling failure probability of the tank under different wind speeds, water depths, water velocities and filling rates, draw the vulnerability curve of the tank under the coupling of floods and hurricanes, and analyze the impact of different wind speeds, water velocities, water depths and filling rates on the tank.

[0066] Compared with the prior art, the present invention has the following beneficial effects:

[0067] The present invention aims at the coupling effect of flood and hurricane, considers wind load, flood load and wave load, establishes the limit state equation of storage tank buckling failure under the coupling effect of flood and hurricane, and accurately calculates the probability of storage tank buckling failure under the coupling effect of hurricane and flood according to the basic information of storage tank, wind speed, flood speed, flood depth and other information. This method has important guiding significance for analyzing the safety performance of vertical storage tanks under the coupling effect of flood and hurricane, and can provide a strong basis for the vulnerability assessment of chemical process equipment under the coupling effect of multiple disasters. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a schematic diagram of the process steps of the present invention.

[0069] Figure 2 This is the stress analysis diagram of buckling failure of a vertical storage tank under the coupling of flood and hurricane.

[0070] Figure 3 It is the Monte Carlo calculation flow chart.

[0071] Figure 4 It is a schematic diagram of the vulnerability curve of buckling failure of a vertical storage tank under the influence of different filling rates under the coupling of flood and hurricane in Example 1;

[0072] Figure 5 It is a schematic diagram of the vulnerability curve of buckling failure of a vertical storage tank under the influence of different water depths under the coupling of flood and hurricane in Example 1;

[0073] Figure 6 It is a schematic diagram of the vulnerability curve of buckling failure of a vertical storage tank under the influence of different water velocities under the coupling of flood and hurricane in Example 1;

[0074] Figure 7 It is a schematic diagram of the vulnerability curve of buckling failure of a vertical storage tank under the influence of different filling rates under the coupling of flood and hurricane in Example 2;

[0075] Figure 8 It is a schematic diagram of the vulnerability curve of buckling failure of a vertical storage tank under the influence of different water depths under the coupling of flood and hurricane in Example 2;

[0076] Fig. 9 It is a schematic diagram of the vulnerability curve of buckling failure of a vertical storage tank under the influence of different water depths under the coupling of flood and hurricane in Example 3;

[0077] Fig.10 Schematic diagram of the vulnerability curve of buckling failure of a vertical storage tank under the influence of different water velocities under the coupling of flood and hurricane in Example 3. DETAILED DESCRIPTION

[0078] The present invention is further described below in conjunction with the accompanying drawings and specific implementations, but the implementation and protection of the present invention are not limited thereto.

[0079] Embodiment 1:

[0080] The vulnerability analysis method of buckling failure of vertical storage tanks under the coupling of flood and hurricane, such as Figure 1 As shown, the following steps are included:

[0081] S1. Determine the basic information of the vertical storage tank;

[0082] The basic information of vertical storage tanks includes: tank diameter D, tank height H, tank thickness t i , Young's modulus E, density of the medium in the tank ρ l and filling rate

[0083] S2. Conduct a force analysis of the buckling failure of a vertical storage tank under the coupling of flood and hurricane to determine the forces acting on the tank wall of the vertical storage tank;

[0084] The forces on the tank wall during the buckling failure of a vertical storage tank under the coupling of flood and hurricane include the forces of wind load, flood load and wave load on the tank wall;

[0085] In the coupling of flood and hurricane, in addition to flood load and wind load, it also includes wave load caused by the interaction between flood and hurricane; wind load, flood load and wave load act on different parts of the tank wall, as follows:

[0086] Hurricanes, or wind loads, can create strong wind pressure on the top of the tank;

[0087] The hydrostatic and hydrodynamic pressures of the flood load act on the bottom of the tank and increase as the water level rises;

[0088] Hurricanes blowing over the water create waves, and storage tanks above the water level are subject to the forces of wave loads.

[0089] Figure 2 This is the stress analysis diagram of buckling failure of a vertical storage tank under the coupling of flood and hurricane.

[0090] S3. Calculate the resistance load of the vertical storage tank according to the basic information of the vertical storage tank;

[0091] The calculation formula for the tank resistance load is:

[0092]

[0093]

[0094] P r =P l +Pcr

[0095] Among them, P l P is the static pressure generated by the liquid in the tank; cr is the critical pressure of the tank; P r is the total resistance pressure of the tank; ρ l is the density of the liquid in the tank; is the tank filling rate; E is Young's modulus; g is the acceleration of gravity; t i is the tank wall thickness; D is the tank diameter; H is the tank height.

[0096] S4. Determine the range and distribution of random parameters based on historical statistical accident data and calculate the external forces acting on the vertical storage tank;

[0097] As shown in Table 1, based on historical statistical accident data, the random parameters include water depth, water speed, wind speed and filling rate.

[0098] Table 1 Related numerical parameters and their distribution

[0099]

[0100] The wind pressure acting on the storage tank is as follows:

[0101] P wind =C P (θ)P0

[0102]

[0103]

[0104] q eq =k w P max

[0105]

[0106] Among them, C P (θ) is the wind pressure coefficient of the tank at different circumferential angles θ; θ is the circumferential angle; P0 is the reference wind pressure; ρ air V is the air density under standard atmospheric pressure; wind is wind speed; P max is the maximum wind pressure of non-uniform distribution; w0 is the length parameter of the tank wall, C θ is the external pressure buckling coefficient; q eq is the equivalent uniform wind pressure; k w is the equivalent wind pressure coefficient. According to European standard EN1993-1-6, k w The value range is [0.65,1].

[0107] The hydrostatic and hydrodynamic pressures of flood loads acting on the bottom of the tank are as follows:

[0108] P s =ρ w gh

[0109]

[0110] Among them, P s is the hydrostatic pressure; ρ w is the flood density; h is the depth of the flood inundating the storage tank; P d is the dynamic water pressure; C d is the resistance coefficient; V w is the flood velocity;

[0111] like Figure 2 As shown, with the horizontal plane as the X-axis and the vertical direction perpendicular to the horizontal plane as the Z-axis, a rectangular coordinate system is established. The forces acting on the storage tank by the wave load are as follows:

[0112]

[0113]

[0114]

[0115] Among them, H w is the wave height; k is the wave number, w is the wave frequency, J′1(kd) is the derivative of the first-kind Bessel function, Y′1(kd) is the derivative of the second-kind Bessel function; d is the tank radius; f x (z) is the wave force per unit length in the Z direction; z is the independent variable; L is the wavelength; cosh(kh) is the hyperbolic cosine function with kh as the independent variable; δ is a constant, which is calculated by the formula.

[0116] The horizontal wave force F1 on the tank wall below the water surface is as follows:

[0117]

[0118] The horizontal wave force F2 on the tank wall above the water surface is as follows:

[0119]

[0120] Among them, H s H is the vertical distance from the wave crest to the horizontal plane, s =0.7H w .

[0121] The calculation formula of wave elements is as follows:

[0122]

[0123]

[0124]

[0125] Where T is the wave period; m is the length of the wind zone, and the value of m is 10 km.

[0126] The calculation formula of the external force on the storage tank under the coupling of flood and hurricane is:

[0127]

[0128] Where P is the maximum external force acting on the tank; t is time.

[0129] S5. Based on the judgment basis of tank buckling failure, establish the limit state equation of tank buckling failure under the coupling of flood and hurricane;

[0130] The strong pressure generated by floods and hurricanes may cause the tank wall to buckle. That is, when the external force on the tank wall is greater than the resistance pressure of the tank, the tank buckles and fails.

[0131] The limit state equation of the buckling failure of the storage tank under the coupling of flood and hurricane is:

[0132] Z=PP r =PP cr -P l

[0133] Among them, Z is the limit state function. When Z>0, the tank fails due to buckling.

[0134] S6, such as Figure 3 As shown in the figure, the Monte Carlo simulation method is used to count the number of buckling failures of the target tank and calculate the failure probability, as follows:

[0135] Solve the resistance load of the storage tank;

[0136] The external force on the tank wall is calculated and substituted into the limit state equation to determine whether the tank fails due to buckling.

[0137] In this embodiment, the Monte Carlo calculation program is written using MATLAB software. Taking into account the calculation accuracy and running time, the sampling cycle number is 10. 6 times, calculate the failure probability.

[0138] S7. The Monte Carlo method is used to sample random parameters to obtain the probability of buckling failure of the tank under different wind speeds, water depths, water velocities and filling rates, draw the vulnerability curve of the tank under the coupling of floods and hurricanes, and analyze the impact of different wind speeds, water velocities, water depths and filling rates on the tank.

[0139] In this embodiment, the diameter of the storage tank is 22m and the height of the storage tank is 11m. Figure 4 , Figure 5 and Figure 6 It is the fragility curve of buckling failure of vertical storage tank under the coupling of flood and hurricane.

[0140] Embodiment 2:

[0141] In this embodiment, the tank diameter is 15m, the tank height is 10m, and the vertical tank buckling failure vulnerability analysis method under the coupling of flood and hurricane is selected. A vertical tank type different from that in Example 1 is selected. The tank diameter is 15m, the tank height is 10m, the tank thickness is 0.015m, and the tank filling rate varies uniformly between 0-0.7, that is, the filling rate (0, 0.7), and the rest is the same as Example 1. According to the above seven steps, the buckling failure probability of the storage tank under different wind speeds, water depths, water velocities and filling rates is obtained, and the vulnerability curve of the storage tank under the coupling of floods and hurricanes is drawn. Figure 7 and Figure 8 It is the fragility curve of buckling failure of vertical storage tank under the coupling of flood and hurricane.

[0142] Embodiment 3:

[0143] In this embodiment, the tank diameter is 27m, the tank height is 12.6m, and the vertical tank buckling failure vulnerability analysis method under the coupling of flood and hurricane is selected. A vertical tank type different from that in Embodiment 1 and Embodiment 2 is selected. The tank diameter is 27m, the tank height is 12.6m, the tank thickness is 0.0125m, and the tank filling rate varies uniformly between 0-0.8, that is, the filling rate (0, 0.8), and the rest is the same as Example 1. According to the above seven steps, the buckling failure probability of the storage tank under different wind speeds, water depths, water velocities and filling rates is obtained, and the vulnerability curve of the storage tank under the coupling of floods and hurricanes is drawn. Fig. 9 and Fig.10 It is the fragility curve of buckling failure of vertical storage tank under the coupling of flood and hurricane.

[0144] As shown in the above embodiments, compared with the prior art, the present invention has the following beneficial effects:

[0145] The present invention aims at the coupling effect of flood and hurricane, considers wind load, flood load and wave load, establishes the limit state equation of storage tank buckling failure under the coupling effect of flood and hurricane, and accurately calculates the probability of storage tank buckling failure under the coupling effect of hurricane and flood according to the basic information of storage tank, wind speed, flood speed, flood depth and other information. This method has important guiding significance for analyzing the safety performance of vertical storage tanks under the coupling effect of flood and hurricane, and can provide a strong basis for the vulnerability assessment of chemical process equipment under the coupling effect of multiple disasters.

Claims

1. A method for analyzing the vulnerability of vertical storage tanks to buckling failure under the coupling of flood and hurricane, characterized in that: The following steps are involved: S1. Determine the basic information of the vertical storage tank; The basic information of vertical storage tanks includes: tank diameter D, tank height H, tank thickness T i , Young's modulus E, density of medium in the tank ρ l and filling rate g is the acceleration due to gravity; S2. Conduct a force analysis of the buckling failure of vertical storage tanks under the coupling of flood and hurricane to determine the forces acting on the vertical storage tanks; S3. Calculate the resistance load of the vertical storage tank based on the basic information of the vertical storage tank; S4. Determine the range and distribution of random parameters based on historical statistical accident data and calculate the external forces acting on the vertical storage tank; According to historical statistical accident data, the random parameters include wind speed, water speed, water depth and filling rate; The wind pressure acting on the storage tank is as follows: P wind =C P (θ)P0 q eq =k w P max Among them, C P (θ) is the wind pressure coefficient of the tank at different circumferential angles θ; θ is the circumferential angle; P0 is the reference wind pressure; ρ air V is the air density under standard atmospheric pressure; wind is wind speed; P max is the maximum wind pressure of non-uniform distribution; w0 is the length parameter of the tank wall, C θ is the external pressure buckling coefficient; q eq is the equivalent uniform wind pressure; k w is the equivalent wind pressure coefficient. According to European standard EN 1993-1-6, k w The value range is [0.65,1]; The hydrostatic and hydrodynamic pressures of flood loads acting on the bottom of the tank are as follows: P s =ρ w gh Among them, P s is the hydrostatic pressure; ρ w is the flood density; h is the depth of the flood inundating the storage tank; P d is the dynamic water pressure; C d is the resistance coefficient; V w is the flood velocity; With the horizontal plane as the X-axis and the vertical direction perpendicular to the horizontal plane as the Z-axis, a rectangular coordinate system is established. The forces acting on the storage tank by the wave load are as follows: Among them, H w is the wave height; k is the wave number, w is the wave frequency, J′1(kd) is the derivative of the first-kind Bessel function, Y′1(kd) is the derivative of the second-kind Bessel function; d is the tank radius; f x (z) is the wave force per unit length in the Z direction; z is the independent variable; L is the wavelength; cosh(kh) is the hyperbolic cosine function with kh as the independent variable; δ is a constant, which is obtained by the formula; The calculation formula of wave elements is as follows: Where, T is the wave period; m is the length of the wind zone; S5. Based on the judgment basis of tank buckling failure, the limit state equation of tank buckling failure under the coupling of flood and hurricane is established; S6. Use the Monte Carlo simulation method to count the number of buckling failures of the target tank and calculate the failure probability; S7. Draw the vulnerability curve of the storage tank under the coupling of flood and hurricane, and analyze the impact of different wind speeds, water speeds, water depths and filling rates on the storage tank.

2. The method for analyzing the buckling failure vulnerability of vertical storage tanks under the coupling of flood and hurricane according to claim 1 is characterized in that: In step S2, the forces acting on the tank wall during buckling failure of the vertical storage tank under the coupling of flood and hurricane include the forces acting on the tank wall by wind load, flood load and wave load; In the coupling of flood and hurricane, in addition to flood load and wind load, it also includes wave load caused by the interaction between flood and hurricane; wind load, flood load and wave load act on different parts of the tank wall, as follows: Hurricanes, or wind loads, can create strong wind pressure on the top of the tank; The hydrostatic and hydrodynamic pressures of the flood load act on the bottom of the tank and increase as the water level rises; Hurricanes blowing over the water create waves, and storage tanks above the water level are subject to the forces of wave loads.

3. The method for analyzing the vulnerability of vertical storage tanks to buckling failure under the coupling of flood and hurricane according to claim 1 is characterized in that: In step S3, the calculation formula for the tank load resistance is: P r =P l +P cr Among them, P l P is the static pressure generated by the liquid in the tank; cr is the critical pressure of the tank; P r is the total resistance pressure of the tank; ρ l is the density of the liquid in the tank; is the tank filling rate; E is Young's modulus; t i is the tank wall thickness; D is the tank diameter; H is the tank height.

4. The method for analyzing the vulnerability of vertical storage tanks to buckling failure under the coupling of flood and hurricane according to claim 1 is characterized in that: The calculation formula of the external force on the storage tank under the coupling of flood and hurricane is: Where P is the maximum external force acting on the tank; t is time.

5. The method for analyzing the vulnerability of vertical storage tanks to buckling failure under the coupling of flood and hurricane according to any one of claims 1 to 4, characterized in that: In step S5, when the external force acting on the tank wall is greater than the resistance pressure of the tank, the tank buckles and fails; The limit state equation of the buckling failure of the storage tank under the coupling of flood and hurricane is: Z=P-P r =P-P cr -P l Among them, Z is the limit state function. When Z>0, the tank fails due to buckling.

6. The method for analyzing the vulnerability of vertical storage tanks to buckling failure under the coupling of flood and hurricane according to claim 5 is characterized in that: In step S6, the Monte Carlo simulation method is used to count the number of buckling failures of the target tank and calculate the failure probability, which is as follows: Solve the resistance load of the storage tank; The external force on the tank wall is calculated and substituted into the limit state equation to determine whether the tank fails due to buckling. Write a Monte Carlo calculation program, taking into account the calculation accuracy and running time, and take the number of sampling cycles as 10 6 times, calculate the failure probability.

7. The method for analyzing the vulnerability of vertical storage tanks to buckling failure under the coupling of flood and hurricane according to claim 6 is characterized in that: In step S7, the Monte Carlo method is used to sample random parameters, calculate the probability of buckling failure of the storage tank under different wind speeds, water depths, water velocities and filling rates, draw the vulnerability curve of the storage tank under the coupling of floods and hurricanes, and analyze the impact of different wind speeds, water velocities, water depths and filling rates on the storage tank.

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