Method for generating earthquake vulnerability curve of water gate chamber structure

Abstract

The invention discloses a method for generating an earthquake vulnerability curve of a water gate chamber structure, which comprises the following steps of: determining a random sample for vulnerability analysis, and adopting a finite element numerical simulation technology to obtain an earthquake vulnerability curve of the water gate chamber structure on the basis of viscoelastic artificial boundary conditions; carrying out nonlinear seismic damage numerical simulation analysis on the random sample by considering an infinite foundation radiation damping effect, concrete dynamic damage, a bonding slippage effect of reinforced concrete and a fluid-solid coupling effect of a water body and a water gate structure; on the basis, discrimination standards of the water gate structure under different damage levels are provided, an earthquake vulnerability analysis method is combined, an earthquake vulnerability curve of the water gate structure under different damage levels is drawn, and the probability change rule of the water gate structure under different damage levels under the earthquake action is analyzed. According to the method, seismic oscillation vulnerability curves under different damage levels are fitted.

Description

Technical Field

[0001] The invention relates to seismic safety analysis, and in particular to a method for generating a seismic vulnerability curve of a sluice chamber structure. Background Art

[0002] Sluice gates have the dual functions of retaining water and releasing water, and are widely used in water conservancy projects. The seismic analysis of sluice gate structures is one of the important contents of the safety review of sluice gate structures. In recent years, a lot of research has been done at home and abroad on the seismic analysis of sluice gate structures.

[0003] Compared with how to accurately conduct seismic numerical simulation analysis on the sluice structure, how to reasonably evaluate the numerical simulation calculation results is also particularly important. At present, the seismic performance evaluation of sluices in my country still uses a single maximum design earthquake as the seismic fortification level, and cannot give the exceedance probability of the sluice reaching different damage levels under the action of earthquakes with different probability levels. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a method for generating seismic vulnerability curves of sluice chamber structures, so as to solve the problem that the existing seismic performance evaluation method of sluice structures is single and cannot give the exceedance probability of the sluice reaching different damage levels under the action of earthquakes with different probability levels.

[0005] Technical solution: The method for generating seismic vulnerability curve of water sluice chamber structure of the present invention comprises the following steps:

[0006] (1) Determine the target response spectrum based on the location of the target building, and use the trigonometric series expansion method to fit the artificial seismic wave;

[0007] (2) The Latin hypercube sampling method is used to determine the random samples for the seismic vulnerability analysis of the sluice chamber structure, and five artificial seismic waves are selected to simulate the uncertainty of the seismic load. The peak acceleration calculated for each seismic wave is selected as 0.1g, 0.15g, 0.2g, 0.3g, 0.4g and 0.5g respectively;

[0008] (3) According to the structural dimensions and reinforcement of the sluice chamber, a three-dimensional finite element model of the sluice chamber structure is established. The model includes the foundation, water body, sluice bottom plate, piers, steel gate, traffic bridge, upper hoist room structure and steel bars in concrete;

[0009] (4) Based on the viscoelastic artificial boundary conditions, taking into account the radiation damping effect of the infinite foundation, the dynamic damage of concrete, the bond-slip effect of reinforced concrete, and the fluid-solid coupling effect of the water body and the sluice structure, the model established in step (3) is used, the random sample determined in step (2), the selected seismic wave, and the determined seismic wave peak acceleration are selected, and the nonlinear dynamic time history calculation of the sluice chamber structure is performed;

[0010] (5) Summarize the calculation results of different samples and, based on the criteria for different damage levels of the sluice structure, calculate the probability of the sluice chamber structure reaching different damage levels and the corresponding peak acceleration values ​​of the seismic motion;

[0011] (6) Based on the data obtained in step (5), a vulnerability curve is obtained by fitting a probability distribution function.

[0012] Optionally, in step (2), the random sample includes the concrete tensile strength R t , concrete fracture energy G f , concrete elastic modulus E h , system damping ratio η and steel elastic modulus E g and the concrete elastic modulus E h , concrete fracture energy G f , concrete tensile strength R t and the elastic modulus of the steel bar E g The probability distribution of the uncertain parameters is assumed to be normal distribution, and the probability distribution of the system damping ratio η is assumed to be uniform distribution. The random sample form is as follows:

[0013]

[0014] The first line is the name of each random variable, and the corresponding column is the sample of each random variable. The samples of each random variable are sorted in a random manner, and each row of samples is used as a sample combination for finite element calculation.

[0015] Optionally, in step (3), the foundation unit range is based on the upstream, downstream, left, right and bottom elevations of the gate bottom plate, and extends upstream, downstream, left bank, right bank and vertically downward by twice the gate chamber height, respectively. The gate chamber height is the difference between the top elevation of the hoist room and the bottom elevation of the gate bottom plate; the upstream and downstream water body unit nodes are shared with the gate pier and steel gate nodes; the steel bar unit nodes are not shared with the concrete unit nodes, and are calculated in the form of interpolation. In the single spring connection unit method, the normal displacement of the steel bar node is calculated according to the following formula, which is as follows:

[0016]

[0017] In the formula, is the displacement value of the i-th dimension of the reinforcement node in the local coordinate system; n is the model dimension; r ij is the interpolation coefficient; u j is the displacement value of the j-th dimension of the concrete node in the global coordinate system.

[0018] When performing nonlinear dynamic time history calculation in step (4), a four-parameter dynamic damage constitutive model is used for concrete, and its failure criterion is:

[0019]

[0020] Where: ε * is the equivalent strain; A, B, C, and D are four test constants obtained by combining uniaxial tension test, uniaxial compression test, biaxial isobaric test, and triaxial compression test; I′1=(ε1+ε2+ε3) / 3 is the first invariant of the strain tensor; is the maximum principal strain; is the second invariant of strain deviator; J′3=ε1ε2ε3 is the third invariant of strain deviator; ε1, ε2, ε3 are the three principal strains respectively; ε m represents the strain under spherical stress;

[0021] Under the action of earthquake load, concrete inevitably has a softening section of unloading and reloading process. The residual strain calculation in this simulation uses the following formula:

[0022]

[0023] In the formula, ε p is the residual strain value, ε0=f t / E is the ultimate strain of concrete under tensile strength, f t is the tensile strength of concrete, E is the elastic modulus of concrete, ε un is the strain value at the unloading point;

[0024] The interaction between steel and concrete is simulated by the single spring coupling element method based on the mixed coordinate system, where the interaction equation between steel and concrete is as follows:

[0025]

[0026] In the formula, Δu, Δu * and ΔF, ΔF * Oxyz and O * x * y * z * Displacement vector increment and load vector increment in the coordinate system; k and k * Oxyz and O * x * y * z * Stiffness matrix in the coordinate system; k s and r are coordinate transformation matrices; r T is the transposed matrix of the coordinate transformation matrix;

[0027] The potential fluid unit is used to simulate the fluid-solid coupling between the water body before and after the gate and the gate pier and steel gate under the action of earthquake. The control equation is as follows:

[0028]

[0029] In the formula, P represents the dynamic water pressure, c is the speed of sound waves in water, is the Laplace operator, is the second-order derivative of the hydrodynamic pressure with respect to time;

[0030] Fluid-structure interaction boundaries are set between the water body and the gate pier, gate bottom plate, and steel gate to simulate the energy transfer between the water body and the steel gate, as follows:

[0031]

[0032] Where n is the external normal direction of the fluid domain on the fluid-solid coupling surface; is the absolute acceleration in the normal direction of the fluid-structure interaction surface, and ρ is the water density.

[0033] Optionally, in step (5), the criteria for distinguishing different damage levels of the sluice structure are as follows:

[0034]

[0035] The probability of the sluice structure reaching different damage levels under a certain earthquake intensity is calculated using the following formula:

[0036]

[0037] Where P(LS|IM=im) is the conditional probability that the concrete dam reaches a certain performance level or limit state LS under the earthquake intensity im; N and M represent the number of random samples and the number of earthquakes respectively; N LS It is the number of gate structures that exceed a certain performance level or limit state LS at each earthquake intensity in the N×M times sluice structure calculation and analysis model.

[0038] Optionally, the fragility curve in step (6) has the earthquake peak acceleration as the horizontal axis and the probability under different damage states as the vertical axis;

[0039] The log-normal distribution function of the vulnerability curve is:

[0040]

[0041] Where F(im) is the probability that the sluice structure reaches a certain performance level or limit state LS under the earthquake intensity; Φ(·) represents the standard normal distribution function; η im and β imare the logarithmic mean and logarithmic standard deviation of the earthquake intensity parameter IM, respectively.

[0042] Beneficial effects: The present invention determines random samples for vulnerability analysis, and adopts finite element numerical simulation technology, considering the influence of factors such as dynamic damage of concrete, bond-slip effect of reinforced concrete, and fluid-solid coupling effect of water body and sluice structure, to perform nonlinear seismic damage numerical simulation analysis on random samples; proposes a discrimination standard for sluice structure at different damage levels, and based on the calculation results, combined with the seismic vulnerability analysis method, draws the seismic vulnerability curve of the sluice structure at different damage levels, analyzes the probability change law of different damage levels of the sluice structure under the action of earthquake, and solves the problem that the existing method for evaluating the seismic performance of sluice structure is single and cannot give the exceedance probability of the sluice reaching different damage levels under the action of earthquakes with different probability levels. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is the overall finite element model of the shallow hole gate chamber structure;

[0044] Figure 2 It is the finite element model of the shallow hole gate chamber structure;

[0045] Figure 3 It is the finite element model of the shallow hole gate pier and gate bottom plate;

[0046] Figure 4 Finite element model of shallow hole steel gate;

[0047] Figure 5 Finite element model of shallow hole gate hoisting and closing machine room

[0048] Figure 6 It is the finite element model of the steel bar inside the bent column of the shallow hole gate hoist room;

[0049] Figure 7 It is the finite element model of the shallow hole gate maintenance bridge;

[0050] Figure 8 It is a finite element model of a shallow hole gate highway bridge;

[0051] Fig. 9 It is the finite element model of the steel gate of the flood control gate and the water body in front of the gate;

[0052] Fig.10 is the standard design response spectrum;

[0053] Fig.11 is a certain acceleration time history curve;

[0054] Fig.12 is another acceleration time history curve;

[0055] Fig.13is a certain speed-time curve;

[0056] Fig.14 is another speed time history curve;

[0057] Fig.15 is a displacement time history curve;

[0058] Fig.16 is another displacement time history curve;

[0059] Fig.17 It is the seismic vulnerability curve of the chamber structure of the horizontal shallow-hole gate with slight damage;

[0060] Fig.18 It is the seismic vulnerability curve of the shallow-hole gate chamber structure with general damage level;

[0061] Fig.19 It is the seismic vulnerability curve of the shallow-hole gate chamber structure with medium damage level;

[0062] Fig. 20 It is the seismic vulnerability curve of the chamber structure of the horizontal shallow hole gate that is severely damaged;

[0063] Fig.21 is the seismic vulnerability curve of shallow-hole gate chamber structure with different damage levels; DETAILED DESCRIPTION

[0064] The present invention is further described below in conjunction with the accompanying drawings and specific examples.

[0065] The chamber structure of a shallow hole gate of a hub project has 22 holes, 2 holes in a unit, and new bridgeheads are built on both sides. There are gaps between the side walls of the bridgeheads and the side piers on both sides. For the convenience of analysis, a three-dimensional finite element analysis is performed on the middle hole of the shallow hole gate.

[0066] According to the structural characteristics of the flood control gate, a three-dimensional finite element model including the foundation, water body, gate bottom plate, gate pier, steel gate, highway bridge, upper hoisting and closing machine room and steel bars was established. The specific model is as shown in the attached manual. Figure 1-8 As shown. Among them, the scope of the foundation unit is based on the upstream, downstream, left, right and bottom elevations of the gate bottom plate, and extends upstream, downstream, left bank, right bank and vertically downward by 2 times the height of the gate chamber, respectively. The gate chamber height is the difference between the top elevation of the gate room and the bottom elevation of the gate bottom plate. The model has a total of 198,140 nodes and 162,958 units, all of which are spatially discretized using eight-node hexahedral units. The Cartesian coordinate system is used, with the cross-river direction as the X direction, the downstream direction as the Y direction, and the vertical direction as the Z direction.

[0067] At the same time, in order to facilitate the establishment of the model, the upstream and downstream water unit nodes are shared with the gate pier and steel gate nodes; the steel unit nodes are not shared with the concrete unit nodes, and the calculation is performed in the form of interpolation. In the single spring connection unit method, the normal displacement of the steel node is calculated according to the following formula. The specific formula is as follows:

[0068]

[0069] In the formula, is the displacement value of the i-th dimension of the reinforcement node in the local coordinate system; n is the model dimension; r ij is the interpolation coefficient, i.e. the coordinate transformation matrix element; u j is the displacement value of the j-th dimension of the concrete node in the global coordinate system.

[0070] The water levels before and after the gate under normal water storage level conditions of the shallow hole gate chamber structure are shown in Table 1.

[0071] Table 1 Water levels before and after the gate under normal water storage level conditions of the shallow hole gate chamber structure

[0072]

[0073] The structural material parameters of the flood gate chamber are shown in Table 2.

[0074] Table 2 Concrete material parameters of shallow hole gate chamber structure

[0075]

[0076] It should be pointed out that according to the "Standard for Seismic Design of Hydraulic Structures" (GB 51247-2018), the elastic modulus of concrete materials is increased by 50% on the basis of the static elastic modulus, the standard value of concrete dynamic compressive strength is increased by 20% compared with the standard value of static compressive strength, and the standard value of concrete dynamic tensile strength is 10% of the standard value of dynamic compressive strength. In addition, the water density in this numerical simulation is 1000kg / m 3 , the bulk modulus is 2.3 GPa.

[0077] According to the China Earthquake Motion Parameter Zoning Map (GB18306-2015), the earthquake fortification intensity in the hub project area is VIII, and the characteristic period of the foundation response spectrum of this project is T g Take 0.35s. According to the "Seismic Design Standard for Hydraulic Structures" (GB51247-2018), the horizontal design acceleration representative value α of the flood gate's middle hole lock chamber structure is h =0.2g. At the same time, according to the provisions of Table 4.3.3 of the "Standard for Seismic Design of Hydraulic Structures" (GB 51247-2018), the representative value of the maximum value of the response spectrum of the sluice structure β maxTaking 2.25, the sluice gate should consider the horizontal seismic effects both along the river direction and perpendicular to the river direction.

[0078] Attached Fig.10 This is the schematic diagram of the design response spectrum used in this calculation. According to this design response spectrum, the earthquake acceleration time history curve is generated by the trigonometric series expansion method. The generated curve needs to be analyzed for autocorrelation and cross-correlation to ensure that the fitted seismic wave is reasonable. The following autocorrelation function is used to perform autocorrelation analysis on the generated artificial seismic wave:

[0079]

[0080] In the formula, p f is the dimensionless autocorrelation function; R f is the autocorrelation function; R0 is the correlation of the same data; a r (r=1,2…N) is the acceleration value at any time; a r+f is the acceleration value at any other time. fΔt is the data a r and data a r+f The time interval between two adjacent data is Δt. When f=0, it indicates the correlation of the same data, which is R0.

[0081] The following cross-correlation function is used to perform cross-correlation analysis on the generated artificial seismic waves:

[0082]

[0083] In the formula, r f is the cross-correlation function; x k is the acceleration value at any time of an acceleration time history curve, (k=1,2…N); y k is the acceleration value of another acceleration time history curve at any time, y k+f It is the acceleration value at any other time of the acceleration time history curve.

[0084] Take two earthquake acceleration time history curves as examples. Figure 11-12 Two earthquake acceleration time history curves after autocorrelation and cross-correlation analysis are given, and the velocity and displacement time history curves are obtained by integration, as shown in the attached figure. Figure 13-14 and attached Figure 15-16 As shown, in the calculation process, based on the viscoelastic artificial boundary conditions, the velocity wave and displacement wave are input vertically from the bottom of the foundation.

[0085] The Latin hypercube sampling method is used to determine the random samples for seismic vulnerability analysis of the lock chamber structure. The random samples include the tensile strength R t , concrete fracture energy G f , concrete elastic modulus E h, system damping ratio η and steel elastic modulus E g and the concrete elastic modulus E h , concrete fracture energy G f , concrete tensile strength R t and the elastic modulus of the steel bar E g The probability distribution of the uncertain parameters is assumed to be normal distribution, and the probability distribution of the system damping ratio η is assumed to be uniform distribution.

[0086]

[0087] The sample format is as above. The first line is the name of each random variable, and the corresponding column is the sample of each random variable. The samples of each random variable are sorted in a random manner, and each row of samples is used as a sample combination for finite element calculation. At the same time, for seismic loads, 5 artificial seismic waves are selected to simulate the uncertainty of seismic loads. The peak acceleration a is calculated for each seismic wave. PGA The selected amounts are 0.1g, 0.15g, 0.2g, 0.3g, 0.4g and 0.5g respectively.

[0088] For the above sample combination, the finite element numerical simulation technology is used, based on the viscoelastic artificial boundary conditions, taking into account the radiation damping effect of the infinite foundation, the dynamic damage of concrete, the bond slip of reinforced concrete, and the fluid-solid coupling of the water body and the sluice structure, to perform seismic calculation and analysis on the lock chamber structure. During the calculation, the concrete adopts a four-parameter dynamic damage constitutive model, and its failure criterion is:

[0089]

[0090] Where: ε * is the equivalent strain; A, B, C, D are four test constants, which can be obtained by combining uniaxial tension test, uniaxial compression test, biaxial isobaric test and triaxial compression test; I′1=(ε1+ε2+ε3) / 3 is the first invariant of the strain tensor; is the maximum principal strain; is the second invariant of strain deviator; J′3=ε1ε2ε3 is the third invariant of strain deviator; ε1, ε2, ε3 are the three principal strains respectively; ε m represents the strain under spherical stress.

[0091] Under the action of earthquake load, concrete inevitably has a softening section of unloading and reloading process. The residual strain calculation in this simulation uses the following formula:

[0092]

[0093] In the formula, ε p is the residual strain value; ε0=ft / E is the ultimate strain of concrete under tensile strength, f t is the tensile strength of concrete, E is the elastic modulus of concrete; ε un is the strain value at the unloading point.

[0094] The interaction between steel and concrete is simulated by the single spring coupling element method based on the mixed coordinate system, where the interaction equation between steel and concrete is as follows:

[0095]

[0096] In the formula, Δu, Δu * and ΔF, ΔF * Oxyz and O * x * y * z * Displacement vector increment and load vector increment in the coordinate system; k and k * Oxyz and O * x * y * z * Stiffness matrix in the coordinate system; k s and r are coordinate transformation matrices; r T is the transposed matrix of the coordinate transformation matrix.

[0097] The potential fluid unit is used to simulate the fluid-solid coupling between the water body before and after the gate and the gate pier and steel gate under the action of earthquake. The control equation is as follows:

[0098]

[0099] In the formula, P represents the dynamic water pressure, c is the speed of sound waves in water, is the Laplace operator, is the second-order derivative of the hydrodynamic pressure with respect to time.

[0100] Fluid-structure interaction boundaries are set between the water body and the gate pier, gate bottom plate, and steel gate to simulate the energy transfer between the water body and the steel gate, as follows:

[0101]

[0102] Where n is the external normal direction of the fluid domain on the fluid-solid coupling surface; is the absolute acceleration in the normal direction of the fluid-structure interaction surface, and ρ is the water density.

[0103] According to the results of the sluice earthquake damage investigation and the statistical results of a large number of sluice earthquake safety review calculations, the damage state of the sluice chamber structure is defined, and the cross-sectional area ratio of the concrete damage area of ​​the sluice chamber structure under the earthquake is used to determine the different damage levels of the sluice chamber structure. The specific judgment criteria are as follows:

[0104]

[0105] Based on the above calculation results and the above judgment criteria, the probability of the lock chamber structure reaching different damage levels and the corresponding peak acceleration values ​​of the earthquake motion are statistically calculated, and the fragility curve is obtained by fitting the probability distribution function. Among them, the probability of the lock structure reaching different damage levels under a certain earthquake motion intensity is calculated by the following formula:

[0106]

[0107] Where P(LS|IM=im) is the conditional probability that the concrete dam reaches a certain performance level or limit state LS under the earthquake intensity im; N and M represent the number of random samples and the number of earthquakes respectively; N LS It is the number of gate structures that exceed a certain performance level or limit state LS at each earthquake intensity in the N×M times sluice structure calculation and analysis model.

[0108] The vulnerability curve adopts the log-normal distribution function, which is

[0109]

[0110] Where F(im) is the probability that the sluice structure reaches a certain performance level or limit state LS under the earthquake intensity; v(·) represents the standard normal distribution function; η im and β im They are the logarithmic mean and logarithmic standard deviation of the seismic intensity parameter IM. The fragility curve is drawn with the earthquake peak acceleration as the horizontal axis and the probability of different damage states as the vertical axis.

[0111] Attached Figure 17-20 The seismic vulnerability curve of the chamber structure of the shallow hole gate under different damage levels is given. As can be seen from the figure, with the increase of the peak acceleration of the earthquake, the probability of occurrence of different damage levels gradually increases. Taking the peak acceleration of the earthquake of 0.1g as an example, under the peak acceleration of the earthquake, the probability of exceeding the minor damage is 87.1%, the probability of exceeding the general damage is 80.5%, the probability of exceeding the moderate damage is 52.2%, and the probability of exceeding the severe damage is 22.7%. It can be seen that the seismic vulnerability curve can intuitively reflect the probability of the chamber structure reaching a certain damage level under different earthquake motions.

[0112] In order to more intuitively reflect the probability of occurrence of different damage levels under the same earthquake load, the attached Fig.21 The comparison of seismic vulnerability curves of shallow hole gate chamber structures under different damage levels is given. It can be seen that under the same earthquake peak acceleration, the exceedance probability of slight damage is the highest, followed by general damage, medium damage is relatively low, and severe damage is the lowest; at the same time, under the same exceedance probability of different damage levels, the required earthquake peak acceleration for slight damage level is smaller, the general damage level is relatively large, the medium damage level is relatively large, and the severe damage level is the highest.

Claims

1. A method for generating seismic vulnerability curve of a sluice chamber structure, characterized in that: The following steps are involved: (1) Determine the target response spectrum based on the location of the target building, and use the trigonometric series expansion method to fit the artificial seismic wave; (2) The Latin hypercube sampling method is used to determine the random samples for the seismic vulnerability analysis of the sluice chamber structure, and five artificial seismic waves are selected to simulate the uncertainty of the seismic load. The peak acceleration calculated for each seismic wave is selected as 0.1g, 0.15g, 0.2g, 0.3g, 0.4g and 0.5g respectively; (3) According to the structural dimensions and reinforcement of the sluice chamber, a three-dimensional finite element model of the sluice chamber structure is established. The model includes the foundation, water body, sluice bottom plate, piers, steel gate, traffic bridge, upper hoist room structure and steel bars in concrete; (4) Based on the viscoelastic artificial boundary conditions, taking into account the radiation damping effect of the infinite foundation, the dynamic damage of concrete, the bond-slip effect of reinforced concrete, and the fluid-solid coupling effect of the water body and the sluice structure, the model established in step (3) is used, the random sample determined in step (2), the selected seismic wave, and the determined seismic wave peak acceleration are selected, and the nonlinear dynamic time history calculation of the sluice chamber structure is performed; (5) Summarize the calculation results of different samples and, based on the criteria for different damage levels of the sluice structure, calculate the probability of the sluice chamber structure reaching different damage levels and the corresponding peak acceleration values ​​of the seismic motion; (6) Based on the data obtained in step (5), a vulnerability curve is obtained by fitting a probability distribution function.

2. The method for generating seismic vulnerability curve of sluice chamber structure according to claim 1, characterized in that: In step (2), the random sample includes the concrete tensile strength R t , concrete fracture energy G f , concrete elastic modulus E h , system damping ratio η and steel elastic modulus E g and the concrete elastic modulus E h , concrete fracture energy G f , concrete tensile strength R t and the elastic modulus of the steel bar E g The probability distribution of the uncertain parameters is assumed to be normal distribution, and the probability distribution of the system damping ratio η is assumed to be uniform distribution. The random sample form is as follows: The first line is the name of each random variable, and the corresponding column is the sample of each random variable. The samples of each random variable are sorted in a random manner, and each row of samples is used as a sample combination for finite element calculation.

3. The method for generating seismic vulnerability curve of sluice chamber structure according to claim 1, characterized in that: In the step (3), the foundation unit range is based on the upstream, downstream, left, right and bottom elevations of the gate bottom plate, and extends upstream, downstream, left bank, right bank and vertically downward by twice the gate chamber height, respectively. The gate chamber height is the difference between the top elevation of the hoist room and the bottom elevation of the gate bottom plate; the upstream and downstream water body unit nodes are shared with the gate pier and steel gate nodes; the steel bar unit nodes are not shared with the concrete unit nodes, and are calculated in the form of interpolation. In the single spring connection unit method, the normal displacement of the steel bar node is calculated according to the following formula, which is as follows: In the formula, is the displacement value of the i-th dimension of the reinforcement node in the local coordinate system; n is the model dimension; r ij is the interpolation coefficient; u j is the displacement value of the j-th dimension of the concrete node in the global coordinate system.

4. The method for generating seismic vulnerability curve of sluice chamber structure according to claim 1, characterized in that: When performing nonlinear dynamic time history calculation in step (4), a four-parameter dynamic damage constitutive model is used for concrete, and its failure criterion is: Where: ε * is the equivalent strain; A, B, C, and D are four test constants obtained by combining uniaxial tension test, uniaxial compression test, biaxial isobaric test, and triaxial compression test; I′1=(ε1+ε2+ε3) / 3 is the first invariant of the strain tensor; is the maximum principal strain; is the second invariant of strain deviator; J′3=ε1ε2ε3 is the third invariant of strain deviator; ε1, ε2, ε3 are the three principal strains respectively; ε m represents the strain under spherical stress; Under the action of earthquake load, concrete inevitably has a softening section of unloading and reloading process. The residual strain calculation in this simulation uses the following formula: In the formula, ε p is the residual strain value, ε0=f t / E is the ultimate strain of concrete under tensile strength, f t is the tensile strength of concrete, E is the elastic modulus of concrete, ε un is the strain value at the unloading point; The interaction between steel and concrete is simulated by the single spring coupling element method based on the mixed coordinate system, where the interaction equation between steel and concrete is as follows: In the formula, Δu, Δu * and ΔF, ΔF * Oxyz and O * x * y * z * Displacement vector increment and load vector increment in the coordinate system; k and k * Oxyz and O * x * y * z * Stiffness matrix in the coordinate system; k s and r are coordinate transformation matrices; r T is the transposed matrix of the coordinate transformation matrix; The potential fluid unit is used to simulate the fluid-solid coupling between the water body before and after the gate and the gate pier and steel gate under the action of earthquake. The control equation is as follows: In the formula, P represents the dynamic water pressure, c is the speed of sound waves in water, is the Laplace operator, is the second-order derivative of the hydrodynamic pressure with respect to time; Fluid-structure interaction boundaries are set between the water body and the gate pier, gate bottom plate, and steel gate to simulate the energy transfer between the water body and the steel gate, as follows: Where n is the external normal direction of the fluid domain on the fluid-solid coupling surface; is the absolute acceleration in the normal direction of the fluid-structure interaction surface, and ρ is the water density.

5. The method for generating seismic vulnerability curve of sluice chamber structure according to claim 1, characterized in that: In step (5), the criteria for distinguishing different damage levels of the sluice structure are as follows: The probability of the sluice structure reaching different damage levels under a certain earthquake intensity is calculated using the following formula: Where P(LS|IM=im) is the conditional probability that the concrete dam reaches a certain performance level or limit state LS under the earthquake intensity im; N and M represent the number of random samples and the number of earthquakes respectively; N LS It is the number of gate structures that exceed a certain performance level or limit state LS at each earthquake intensity in the N×M times sluice structure calculation and analysis model.

6. The method for generating seismic vulnerability curve of sluice chamber structure according to claim 1, characterized in that: In step (6), the fragility curve has the earthquake peak acceleration as the horizontal axis and the probability under different damage states as the vertical axis; The log-normal distribution function of the vulnerability curve is: Where F(im) is the probability that the sluice structure reaches a certain performance level or limit state LS under the earthquake intensity; Φ(·) represents the standard normal distribution function; η im and β im are the logarithmic mean and logarithmic standard deviation of the earthquake intensity parameter IM, respectively.

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