Ship impact resistance toughness evaluation method for long-piled wharf

Abstract

The invention discloses a ship impact resistance toughness evaluation method for a long-piled wharf, and belongs to the technical field of port engineering, and the ship impact resistance toughness evaluation method for the long-piled wharf comprises the following steps: collecting information of the long-piled wharf and a ship; acquiring a displacement ductility ratio data set of the pile foundation of the high-pile wharf under different ship masses and different impact speeds; establishing a corresponding relation between the damage index and the damage state of the pile foundation of the high-pile wharf; the damage probability and the exceeding probability of the high-pile wharf in different damage states under different ship masses are obtained, and vulnerability curves of the high-pile wharf in different damage states are generated; carrying out recoverability analysis on the high-pile wharf; and establishing a high-pile wharf toughness evaluation index system. According to the method, vulnerability analysis and recoverability after impact of the ship on the high-pile wharf are scientifically disclosed from the perspective of probability theory, full-chain closed-loop analysis of impact process simulation, damage probability and toughness quantitative evaluation is realized, and the overall safety of the high-pile wharf is improved.

Description

Technical Field

[0001] The invention relates to the technical field of port engineering, and in particular to a method for evaluating the toughness of a high-pile dock against ship impact. Background Art

[0002] As the main structural form of port construction, high-pile docks are widely used in my country's port projects due to their advantages such as light weight, good wave-breaking effect, and adaptability to soft soil foundations. However, during their entire life cycle, high-pile docks are often threatened by extreme dynamic loads such as typhoons, earthquakes, and ship collisions. In particular, as the trend of large-scale ships intensifies, collision accidents of ships that exceed the standard design occur frequently, making the dynamic response mechanism and damage evolution law of dock structures under impact loads a key safety issue.

[0003] Seismic resilience is defined as the ability of a building to maintain or restore its original function after being subjected to a certain level of earthquake, and seismic resilience index is a parameter used to evaluate the ability of a building to maintain or restore its original function under earthquake. At present, research on structural resilience at home and abroad is mainly concentrated in the field of seismic resilience, and the research objects are mostly houses and bridges. There is a serious lack of research on structural resilience under ship impact loads, and the existing resilience evaluation system lacks differentiated analysis of buildings of different structural types, functions and importance. It is difficult to conduct accurate quantitative risk assessment of ship collision accidents, and it is difficult to accurately predict and analyze the impact of impact loads on the dock structure to guide the reinforcement design and maintenance decisions of high-pile docks, which affects the overall safety of high-pile docks. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a method for assessing the ship impact toughness of a high-pile dock, which can accurately quantitatively assess the risk of a ship impact accident, reduce the disaster risk and operation and maintenance costs, improve the overall safety of the high-pile dock, and extend the service life of the dock.

[0005] The method for evaluating the ship impact resistance of a high-pile dock according to an embodiment of the present invention includes: S1: Collect the structural design information, component material information and ship information of the high-pile wharf; S2: Establish a finite element simulation model of a ship colliding with a high-pile dock, use the finite element simulation model to simulate the ship collision process, and obtain the displacement ductility ratio data set of the pile foundation of the high-pile dock under different ship masses and different impact speeds; S3: Obtain the corresponding relationship between the bending moment and curvature of the pile foundation section, determine the critical value of the pile foundation under different damage states through the corresponding relationship between the bending moment and curvature of the pile foundation section, and establish the corresponding relationship between the damage index and damage state of the high-pile wharf pile foundation in combination with the displacement ductility ratio data set; S4: According to the corresponding relationship between the damage index and damage state of the pile foundation of the high-pile wharf, the damage probability and exceedance probability of the high-pile wharf under different damage states under different ship masses are obtained, and then the vulnerability curve of the high-pile wharf under different damage states is generated; S5: Conduct recoverability analysis of high-pile piers according to different damage states of high-pile piers; S6: By coupling the fragility curve and the recoverability analysis results, the toughness evaluation index of the high-pile dock based on different recovery functions is calculated to achieve a quantitative assessment of the toughness level of the dock structure under ship impact conditions.

[0006] The ship impact toughness assessment method of a piled wharf according to an embodiment of the present invention has at least the following beneficial effects: by integrating the structural parameters of the piled wharf and the characteristic data of the ship to construct a simulation model to analyze and simulate the entire process of ship impact, the dynamic response of the pile foundation is quantitatively obtained, and then a probability statistical model is established based on the quantitative relationship between the damage index and the damage state to simulate the vulnerability curve of the piled wharf under different working conditions. On this basis, the recoverability analysis of the piled wharf is carried out in combination with the damage state classification, and finally the toughness index of the ship impacting the piled wharf is solved by coupling the vulnerability analysis and the recoverability analysis, and the vulnerability analysis of the ship impacting the piled wharf and the recoverability after the impact are scientifically revealed from the perspective of probability theory. A ship impact toughness assessment method for the piled wharf is established, and a full-chain closed-loop analysis of the impact process simulation, damage probability, and quantitative toughness assessment is realized, as well as the quantification of the dynamic damage of the wharf caused by the ship impact, so as to guide the reinforcement design and maintenance decision of the piled wharf, thereby reducing the disaster risk and operation and maintenance costs, extending the service life of the wharf, and improving the overall safety of the piled wharf, providing a theoretical reference for the evaluation and analysis of the toughness of the piled wharf under the impact of ships in the future.

[0007] According to some embodiments of the present invention, in S1, the structural design information includes the type and size of the wharf structure, the component material information includes the concrete strength, steel bar size and steel bar strength, and the ship information includes the maximum berthing ship mass and ship impact speed designed for the wharf.

[0008] According to some embodiments of the present invention, in S2, obtaining a displacement ductility ratio data set of a pile foundation of a high-piled pier under different impact speeds under different ship masses includes: constructing a finite element simulation model of a ship colliding with a high-piled pier based on finite element analysis software; assigning corresponding material properties to the ship model and the pier model respectively; using an embedded point method to perform equivalent simplification on the pile-soil interaction; simulating the energy transfer process of a ship colliding with the pier through an explicit dynamic analysis method; and obtaining a displacement ductility ratio data set of a pile foundation of a high-piled pier under different impact speeds under different ship masses.

[0009] According to some embodiments of the present invention, in S3, establishing a correspondence between the damage index of the pile foundation of the high-pile wharf and the damage state includes: obtaining the curvature of the steel bar at the equivalent yield and the curvature of the steel bar at the first yield, and calculating the equivalent yield strength displacement ductility ratio of the pile foundation of the high-pile wharf according to the curvature of the steel bar at the equivalent yield and the curvature of the steel bar at the first yield; obtaining the equivalent height of the pile foundation, the diameter of the longitudinal steel bar and the standard value of the tensile strength of the longitudinal steel bar, and calculating the plastic hinge length of the pile foundation according to the equivalent height of the pile foundation, the diameter of the longitudinal steel bar and the standard value of the tensile strength of the longitudinal steel bar; obtaining the The plastic hinge length is combined with the preset concrete strain curvature, the curvature of the steel bar at equivalent yield and the curvature of the steel bar at the first yield to calculate the displacement ductility ratio under the preset concrete strain value; the maximum displacement ductility ratio under the preset concrete strain value is obtained according to the displacement ductility ratio under the preset concrete strain value; the displacement ductility ratio of the first steel bar yield is obtained, and the damage index defined by the displacement ductility ratio of the pile foundation of the high-pile wharf is determined by combining the equivalent yield strength displacement ductility ratio of the pile foundation of the high-pile wharf, the displacement ductility ratio under the preset concrete strain value and the maximum displacement ductility ratio under the preset concrete strain value.

[0010] According to some embodiments of the present invention, obtaining the damage probability and exceedance probability of a high-pile pier under different damage states under different ship masses includes: determining the probability distribution of the ship pile foundation velocity; randomly generating a pile foundation velocity data set by using the Monte Carlo method; performing finite element explicit dynamic analysis on the pile foundation velocity sample set for different ship mass conditions to obtain a pile foundation displacement ductility ratio data set under different impact velocities; calculating the damage probability under different damage states under different ship masses based on the correspondence between the damage index of the high-pile pier pile foundation and the damage state, and then calculating the exceedance probability under different damage states under different ship masses.

[0011] According to some embodiments of the present invention, the damage status includes five levels: substantially intact, slightly damaged, moderately damaged, severely damaged, and completely damaged.

[0012] According to some embodiments of the present invention, in S5, conducting recoverability analysis of the high-pile pier includes: calculating the destruction probability of the high-pile pier based on the exceedance probability of different damage states, and calculating the remaining function in combination with the function loss ratio of different damage states; obtaining the repair method corresponding to each damage state, and determining the repair time of the pier according to the repair method corresponding to each damage state; using triangular distribution to establish a repair time sample, and obtaining the probability distribution of the repair time by normal distribution fitting.

[0013] According to some embodiments of the present invention, in S6, establishing a high-pile pier resilience evaluation index system based on different recovery functions includes: selecting a recovery function model to describe the high-pile pier function recovery process; calculating the resilience index through the recovery function model; and performing resilience evaluation based on the resilience index.

[0014] According to some embodiments of the present invention, the restoration function includes any one of a linear type, an exponential type and a triangular type, wherein: The mathematical expression of the straight line is: ; The mathematical expression of exponential type is: ; The mathematical expression of the triangle is: ; In the formula, and are two constants fitted through the data, is the initial time of ship collision, is the time of ship collision, For recovery time.

[0015] According to some embodiments of the present invention, determining the toughness evaluation index of a high-pile pier under different ship masses and impact speeds includes: selecting a recovery function; obtaining the initial time of the ship impact and the recovery time of the high-pile pier structure performance, and calculating and obtaining the toughness index based on the recoverability curves corresponding to different damage states.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 This is a flow chart of a method for evaluating the toughness of a high-pile dock against ship impact in this specific embodiment; Figure 2 A Monte Carlo sampling diagram of 1000 groups of ship impact speed values ​​that obey extreme value type I distribution provided in an embodiment of the present invention; Figure 3 A vulnerability curve diagram of a high-pile dock under a ship impact provided by a specific embodiment of the present invention; Figure 4 A curve diagram showing the probability of damage to a high-pile dock caused by a ship impact provided in a specific embodiment of the present invention; Figure 5 A recovery curve diagram of a high-pile dock after a ship impact provided in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0018] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0019] In the description of the present invention, "several" means one or more, "multiple" means more than two, greater than, less than, and exceeding are understood as not including the number itself, and "above", "below", and "within" are understood as including the number itself. If there is a description of "first", "second", etc., it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0020] In the description of the present invention, unless otherwise clearly defined, words such as “setting”, “installation” and “connection” should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0021] Please refer to Figures 1 to 5 This embodiment discloses a method for evaluating the toughness of a high-pile dock against ship impact, comprising: S1: Collect the structural design information, component material information and ship information of the high-pile wharf; S2: Establish a finite element simulation model of a ship colliding with a high-pile dock, use the finite element simulation model to simulate the ship collision process, and obtain the displacement ductility ratio data set of the pile foundation of the high-pile dock under different ship masses and different impact speeds; S3: Obtain the corresponding relationship between the bending moment and curvature of the pile foundation section, determine the critical value of the pile foundation under different damage states through the corresponding relationship between the bending moment and curvature of the pile foundation section, and establish the corresponding relationship between the damage index and damage state of the high-pile wharf pile foundation in combination with the displacement ductility ratio data set; S4: According to the corresponding relationship between the damage index and damage state of the pile foundation of the high-pile wharf, the damage probability and exceedance probability of the high-pile wharf under different damage states under different ship masses are obtained, and then the vulnerability curve of the high-pile wharf under different damage states is generated; S5: Conduct recoverability analysis of high-pile piers according to different damage states of high-pile piers; S6: By coupling the fragility curve and the recoverability analysis results, the toughness evaluation index of the high-pile dock based on different recovery functions is calculated to achieve a quantitative assessment of the toughness level of the dock structure under ship impact conditions.

[0022] By integrating the structural parameters of the high-pile wharf and the characteristic data of the ship, a simulation model is constructed to analyze and simulate the entire process of ship impact, and the dynamic response of the pile foundation is quantitatively obtained. Then, a probability statistical model is established based on the quantitative relationship between the damage index and the damage state, and the vulnerability curve of the high-pile wharf under different working conditions is simulated. On this basis, the recoverability analysis of the high-pile wharf is carried out in combination with the damage state classification. Finally, by coupling the vulnerability analysis and recoverability analysis, the toughness index system of the ship impacting the high-pile wharf is solved. Therefore, from the perspective of probability theory, the vulnerability analysis of the ship impacting the high-pile wharf and the recoverability after the impact are scientifically revealed. A method for evaluating the toughness of the high-pile wharf against ship impact is established, and a full-chain closed-loop analysis from the impact process simulation, damage probability, and quantitative toughness evaluation is realized. The dynamic damage of the ship impact on the wharf is quantified, and a systematic toughness evaluation system is established to guide the reinforcement design and maintenance decisions of the high-pile wharf, reduce disaster risks and operation and maintenance costs, extend the service life of the wharf, and improve the overall safety of the high-pile wharf, providing a theoretical reference for the evaluation and analysis of the toughness of the high-pile wharf under the impact of ships in the future.

[0023] In some specific embodiments of the present invention, in S1, the structural design information includes the type and size of the wharf structure, the component material information includes the concrete strength, steel bar size and steel bar strength, and the ship information includes the maximum berthing ship mass and ship impact speed designed for the wharf.

[0024] In some specific embodiments of the present invention, in S2, obtaining a displacement ductility ratio data set of a pile foundation of a high-pile pier under different impact speeds under different ship masses includes: constructing a finite element simulation model of a ship colliding with a high-pile pier based on finite element analysis software; assigning corresponding material properties to the ship model and the pier model respectively; using the embedded point method to perform equivalent simplification on the pile-soil interaction; simulating the energy transfer process of the ship colliding with the pier through an explicit dynamic analysis method; and obtaining a displacement ductility ratio data set of a pile foundation of a high-pile pier under different impact speeds under different ship masses.

[0025] In some specific embodiments of the present invention, in S3, establishing a corresponding relationship between the damage index of the pile foundation of the high-pile wharf and the damage state includes: S3.1: Obtain the curvature of the steel bar at equivalent yield and the curvature of the steel bar at the first yield. According to the curvature of the steel bar at equivalent yield and the curvature of the steel bar at the first yield, calculate the equivalent yield strength displacement ductility ratio of the pile foundation of the high-pile wharf. The specific calculation formula is as follows: ; In the formula, is the displacement-ductility ratio of the equivalent yield strength of the pile foundation of the high-pile wharf, is the curvature of the steel bar at equivalent yield; is the curvature of the steel bar when it yields for the first time. It should be noted that the corresponding relationship between the moment and curvature of the pile foundation section is determined by using the moment-curvature curve of the pile foundation section. and It can be obtained by analyzing the bending moment-curvature curve of the pile foundation section. Among them, obtaining the bending moment-curvature curve of the pile foundation section belongs to conventional technical means, and its principle will not be further described here.

[0026] S3.2: Obtain the equivalent height of the pile foundation, the diameter of the longitudinal reinforcement, and the standard value of the tensile strength of the longitudinal reinforcement. Calculate the plastic hinge length of the pile foundation based on the equivalent height of the pile foundation, the diameter of the longitudinal reinforcement, and the standard value of the tensile strength of the longitudinal reinforcement. The specific calculation formula is as follows: ; In the formula, is the length of the plastic hinge, is the equivalent height of the pile foundation, is the diameter of the longitudinal reinforcement, It is the standard value of longitudinal steel bar tensile strength.

[0027] S3.3: Obtain the plastic hinge length of the pile foundation, and calculate the displacement ductility ratio under the preset concrete strain value by combining the preset concrete strain curvature, the curvature of the steel bar at equivalent yield, and the curvature of the steel bar at the first yield. The specific calculation formula is as follows: ; In the formula, is the displacement ductility ratio under the preset concrete strain value, is the equivalent height of the pile foundation, is the curvature of the concrete when the strain is equal to 0.004, is the curvature of the steel bar at equivalent yield, is the curvature of the steel bar when it first yields.

[0028] S3.4: Obtain the maximum displacement ductility ratio under the preset concrete strain value according to the displacement ductility ratio under the preset concrete strain value. The specific calculation formula is as follows: ; In the formula, is the maximum displacement ductility ratio under the preset concrete strain value.

[0029] S3.5: Obtain the displacement ductility ratio of the first steel bar yielding, and determine the damage index defined by the displacement ductility ratio of the pile foundation of the high-pile wharf by combining the equivalent yield strength displacement ductility ratio of the pile foundation of the high-pile wharf, the displacement ductility ratio under the preset concrete strain value, and the maximum displacement ductility ratio under the preset concrete strain value.

[0030] In some specific embodiments of the present invention, obtaining the damage probability and exceedance probability of a high-pile wharf under different damage states under different ship masses includes: determining the probability distribution of the ship pile foundation velocity; randomly generating a pile foundation velocity data set by using a Monte Carlo method; performing a finite element explicit dynamic analysis on the pile foundation velocity sample set for different ship mass conditions to obtain a pile foundation displacement ductility ratio data set under different impact velocities; calculating the damage probability under different damage states under different ship masses based on the corresponding relationship between the damage index of the high-pile wharf pile foundation and the damage state, and then calculating the exceedance probability under different damage states under different ship masses.

[0031] In some specific embodiments of the present invention, the damage status includes five levels: substantially intact, slightly damaged, moderately damaged, severely damaged, and completely damaged.

[0032] Specifically, the damage probability of the high-pile dock under different damage states and different ship masses is calculated by the following formula: ; In the formula, ( i =1, 2, 3, 4) are the damage probabilities of slight damage, moderate damage, severe damage and overall failure for different ship masses, respectively. , , and These are the data sets of slight damage, moderate damage, severe damage and overall failure in n groups of ships with different ship masses in the collision simulation. is the number of Monte Carlo sampling.

[0033] After obtaining the damage probability of different ship masses in various damage states, the exceedance probability of the slight damage state is defined as the sum of the probabilities of the slight damage state, moderate damage state, severe damage state and overall failure state, the exceedance probability of the moderate damage state is defined as the sum of the probabilities of the moderate damage state, severe damage state and overall failure state, the exceedance probability of the severe damage state is defined as the sum of the probabilities of the severe damage state and the overall failure state, and the exceedance probability of the overall failure state is defined as the probability of the overall failure state.

[0034] That is, the probability of exceeding the slight damage state corresponding to different ship masses is: = ; The probability of exceeding the medium damage state is = ; The probability of exceeding the severe damage state is = ; The probability of exceeding the overall failure state is = .

[0035] In some specific embodiments of the present invention, in S5, conducting recoverability analysis of the high-pile wharf includes: S5.1: The failure probability of the high-pile wharf is calculated based on the exceedance probability of different failure states. The failure probability of the high-pile wharf is calculated using the following formula: ; Where: The damage state of the dock under the action of a certain ship mass is i The probability of damage, is the exceedance probability of each damage state under the action of a certain ship mass, i is the number of damaged states.

[0036] The residual function is calculated by combining the functional loss ratio of different damage states. The mathematical expression of the residual function loss function is: ; Where: Indication and damage status i The corresponding probability of damage is Damage status i The corresponding function loss ratio is shown in Table 1.

[0037] Table 1 Function loss ratio

[0038] S5.2: Obtain the repair method corresponding to each damage state, as shown in Table 2.

[0039] Table 2 Repair time of each solution

[0040] The repair time of the dock is determined according to the repair method corresponding to each damage state, as shown in Table 3.

[0041] Table 3 Repair time of different damage states

[0042] S5.3: Use triangular distribution to establish repair time samples, and obtain the probability distribution of repair time through normal distribution fitting. It should be noted that due to the randomness of the repair time of the dock, Table 3 is a triangular distribution based on Table 2, which is used to calculate the repair time required for different ship masses to hit the dock. Specifically, based on the distribution of each damage state in Table 3, random sampling follows the triangular distribution preset times combined with the formula to establish a sample of repair time, and then the samples are statistically analyzed to obtain the probability distribution of different repair times, and normal distribution fitting is used to select the mean as the repair time after the ship hits.

[0043] In some specific embodiments of the present invention, in S6, establishing a high-pile wharf resilience evaluation index system based on different recovery functions includes: selecting a recovery function model to describe the high-pile wharf function recovery process; calculating the resilience index through the recovery function model; and performing resilience evaluation based on the resilience index.

[0044] In some specific embodiments of the present invention, the recovery function includes any one of a linear type, an exponential type, and a triangular type, wherein: The mathematical expression of the straight line is: ; The mathematical expression of exponential type is: ; The mathematical expression of the triangle is: ; In the formula, and are two constants fitted through the data, is the initial time of ship collision, is the ship collision time, For recovery time.

[0045] In some specific embodiments of the present invention, determining the toughness evaluation index of the high-pile dock under different ship masses and impact speeds includes: selecting a recovery function; obtaining the initial time of ship impact and the recovery time of the high-pile dock structure performance, and calculating and obtaining the toughness index based on the recoverability curves corresponding to different damage states. Specifically, the calculation formula of the toughness index is as follows: ; In the formula, is the toughness index, is the initial time of ship collision, is the structural performance recovery time of the high-pile wharf, It is the structural function of the high-pile wharf.

[0046] Table 4 Toughness evaluation criteria

[0047] In some specific embodiments of the present invention, reference may be made to Figure 4 The seismic resilience evaluation criteria shown are used for evaluation.

[0048] The following is an explanation of the method for evaluating the toughness of a high-pile wharf against ship impact based on a specific embodiment.

[0049] S1: Collect the structural design information, component material information and ship information of the high-pile wharf.

[0050] S2: Establish a finite element simulation model of a ship colliding with a high-piled pier. Use the finite element simulation model to simulate the ship collision process and obtain a data set of displacement ductility ratio of the pile foundation of the high-piled pier under different ship masses and different impact speeds.

[0051] In this example, the finite element simulation model of a ship colliding with a high-pile dock is established to establish the dock structure design information, material information, and ship information using the parameters in Tables 5 to 7.

[0052] Table 5 Wharf structure design information

[0053] Table 6 Wharf component material information

[0054] Table 7 Ship information

[0055] In a specific embodiment of the present invention, the design of the high-pile wharf to be studied stipulates that the maximum berthing ship mass is 30,000 tons. Therefore, the present invention implements the structural dynamic response analysis of different ship masses (3,000 tons, 5,000 tons, 10,000 tons, 15,000 tons, 20,000 tons, 25,000 tons, and 30,000 tons) under 1,000 groups of random sampling impact velocities obeying extreme value type I distribution. The ship impact velocities obeying extreme value type I distribution are as follows: Figure 2 shown.

[0056] It should be further explained that a large number of numerical analyses are carried out according to the proposed study of different ship masses and different ship impact velocities, so as to obtain the displacement ductility ratio of the pile foundation of the high-piled pier under different ship masses and different impact velocities.

[0057] S3: Obtain the correspondence between the bending moment and curvature of the pile foundation section. Determine the critical value of the pile foundation under different damage states through the correspondence between the bending moment and curvature of the pile foundation section. Combined with the displacement ductility ratio data set, establish the correspondence between the damage index and damage state of the pile foundation of the high-pile wharf.

[0058] It should be further explained that the displacement ductility ratio is selected as the damage index of the wharf based on the performance of the pile foundation damage index. Combined with the curvature parameter obtained by the moment-curvature analysis of the pile foundation section, the critical values ​​of the pile foundation in different damage states are calculated by combining equations (1) to (4): ; In the formula, is the displacement-ductility ratio of the equivalent yield strength of the pile foundation of the high-pile wharf, is the curvature of the steel bar at equivalent yield, is the curvature of the steel bar when it first yields; ; In the formula, is the length of the plastic hinge (m), is the equivalent height of the pile foundation (m), is the diameter of the longitudinal reinforcement (m), is the standard value of longitudinal steel bar tensile strength (MPa); ; In the formula, is the displacement ductility ratio under the preset concrete strain value, is the length of the plastic hinge (m), is the equivalent height of the pile foundation (m), is the curvature of the concrete when the strain is equal to 0.004, is the curvature of the steel bar at equivalent yield, is the curvature of the steel bar when it first yields; ; In the formula, is the maximum displacement ductility ratio under the preset concrete strain value, is the displacement ductility ratio under the preset concrete strain value.

[0059] In a specific embodiment of the present invention, according to the above calculation results, the corresponding relationship between the damage index of the high-pile wharf pile foundation defined by the displacement ductility ratio of the high-pile wharf pile foundation and the damage state can be obtained, as shown in Table 8.

[0060] Table 8 Damage index defined by displacement ductility ratio of pile foundation of high-pile wharf

[0061] It should be noted that It represents the displacement ductility ratio of the first steel bar yielding, and its value is 1.

[0062] S4: According to the corresponding relationship between the damage index and damage state of the pile foundation of the high-pile pier, the damage probability and exceedance probability of the high-pile pier under different damage states under different ship masses are obtained, and then the vulnerability curve of the high-pile pier under different damage states is generated.

[0063] According to the corresponding relationship between the damage state and damage index of the high-pile wharf in Table 8, the damage probability of different ship masses under different damage states is calculated, wherein the damage probability is calculated by the following formula: ； In the formula, ( i=1, 2, 3, 4) are the damage probabilities of slight damage, moderate damage, severe damage and overall failure for different ship masses, respectively. , , and These are the data sets of slight damage, moderate damage, severe damage and overall failure in n groups of ships with different ship masses in the collision simulation. is the number of Monte Carlo samplings. This specific example uses 1000 random samplings.

[0064] Before drawing the fragility curve, we first obtain the damage probability of different ship masses in various damage states, and confirm the exceedance probability of the slight damage state as the sum of the probabilities of the slight damage state, moderate damage state, severe damage state and complete damage state; the exceedance probability of the moderate damage state is confirmed as the sum of the probabilities of the moderate damage state, severe damage state and overall failure state; the exceedance probability of the severe damage state is confirmed as the sum of the probabilities of the severe damage state and the overall failure state; and the exceedance probability of the overall failure state is confirmed as the probability of the overall failure state.

[0065] That is, the probability of exceeding the minor damage state corresponding to different ship masses is: = ; The probability of exceeding the medium damage state is = ; The probability of exceeding the severe damage state is = ; The probability of exceeding the complete destruction state is = , the exceedance probability of each damage state in this specific embodiment is calculated and obtained as shown in Table 9.

[0066] Table 9 Exceedance probability of each damage state

[0067] According to the relationship between the exceedance probability of different ship masses and the damage state of the high-pile dock, the vulnerability curve of the dock in different damage states is drawn, such as Figure 3 shown.

[0068] S5: Conduct recoverability analysis of high-pile piers based on different damage states of the high-pile piers.

[0069] It should be noted that the residual function of a ship hitting a high-pile dock is directly related to its degree of damage. The probability of damage to the high-pile dock is solved by combining the exceedance probability of the vulnerability of different damage states with the following formula: ; In the formula, The damage state of the dock under the action of a certain ship mass is i The probability of damage, is the exceedance probability of each damage state under the action of a certain ship mass, i is the number of failure states. The solution of this specific embodiment is as follows: Figure 4 shown.

[0070] The residual function of the ship hitting the high-pile dock is calculated by combining the function loss ratio of different damage states. The mathematical expression of the residual function loss function is: ; In the formula, Indication and damage status i The corresponding probability of damage is Damage status i The corresponding function loss ratio, the solution results of this specific embodiment are shown in Table 10.

[0071] Table 10 Function loss ratio

[0072] Referring to Tables 11 and 12, to determine the repair time of the high-pile wharf, it is necessary to determine the repair method of the wharf under various damage states, and calculate the repair time based on the damage probability of different damage states of the high-pile wharf. The specific calculation formula is as follows: ; In the formula, Time for repairing the high-pile dock. Indication and damage status i The corresponding probability of damage is Damage status i The corresponding repair time.

[0073] Table 11 Repair time of each solution

[0074] The repair time is affected by many factors such as the repair method, degree of structural damage, material reserves, etc., and there is a certain degree of uncertainty. Therefore, the repair time adopts a triangular distribution form, as shown in Table 12.

[0075] Table 12 Repair time of different damage states

[0076] Based on the distribution of each damage state in Table 12, random sampling follows triangular distribution 1000 times and combines the formula to establish a sample of repair time, and then statistically analyzes the samples to obtain the probability distribution of different repair times. The normal distribution is used for fitting, and the mean is selected as the repair time after the ship collision. The results of this specific embodiment are as follows: Figure 5 shown.

[0077] S6: By coupling the fragility curve and the recoverability analysis results, the toughness evaluation index of the high-pile dock based on different recovery functions is calculated to achieve a quantitative assessment of the toughness level of the dock structure under ship impact conditions.

[0078] The recovery function is mainly used to describe the repair method after the ship hits the high-pile dock. One of the empirical functional recovery functions of linear, exponential and triangular types is used as the recoverability evaluation standard. The mathematical expressions of the three empirical functional recovery functions are as follows: The mathematical expression of the straight line is: ; The mathematical expression of exponential type is: ; The mathematical expression of the triangle is: ; In the formula, and are two constants fitted through the data, is the initial time of ship collision, is the ship collision time, For recovery time.

[0079] Based on the above-mentioned fragility curve and the recoverable curve corresponding to different damage states, the resilience index of the high-pile wharf under different damage states can be obtained. It should be further explained that the linear recovery function is suitable for minor or moderate damage, the repair process does not require complex adjustments, the wharf repair resources are stable, the repair time requirements are predictable and there is no emergency demand, and linear advancement is allowed; the exponential recovery function is for the wharf that needs to restore key functions in a short period of time, such as port navigation capacity, and the resource investment is intensive. The repair progress requires nonlinear acceleration, and the basic functions of the wharf are quickly restored through emergency repairs; the triangular recovery function is suitable for large wharf structures with relatively serious damage, and its repair resources respond relatively slowly, and the repair process needs to be prioritized.

[0080] Specifically, the toughness index of the high-pile wharf structure is calculated from the recoverability curve T corresponding to different damage states, and the following formula is used to calculate the toughness index: ; In the formula, is the toughness index, is the initial time of ship collision, is the structural performance recovery time of the high-pile wharf, It is the structural function of the high-pile wharf; ; In the formula, is the functional loss function, Recover functions for different functions, It is the structural function of the high-pile wharf.

[0081] It should be further explained that this specific embodiment refers to the earthquake resilience evaluation standard and performs evaluation according to Table 4.

[0082] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A method for evaluating the toughness of a high-pile dock against ship impact, characterized in that: include: S1: Collect the structural design information, component material information and ship information of the high-pile wharf; S2: Establish a finite element simulation model of a ship colliding with a high-pile dock, use the finite element simulation model to simulate the ship collision process, and obtain the displacement ductility ratio data set of the pile foundation of the high-pile dock under different ship masses and different impact speeds; S3: Obtain the corresponding relationship between the bending moment and curvature of the pile foundation section, determine the critical value of the pile foundation under different damage states through the corresponding relationship between the bending moment and curvature of the pile foundation section, and establish the corresponding relationship between the damage index and damage state of the high-pile wharf pile foundation in combination with the displacement ductility ratio data set; S4: According to the corresponding relationship between the damage index and damage state of the pile foundation of the high-pile wharf, the damage probability and exceedance probability of the high-pile wharf under different damage states under different ship masses are obtained, and then the vulnerability curve of the high-pile wharf under different damage states is generated; S5: Conduct recoverability analysis of high-pile piers according to different damage states of high-pile piers; S6: By coupling the fragility curve and the recoverability analysis results, the toughness evaluation index of the high-pile dock based on different recovery functions is calculated to achieve a quantitative assessment of the toughness level of the dock structure under ship impact conditions.

2. The method for evaluating the ship impact resistance of a high-pile dock according to claim 1, characterized in that: In S1, the structural design information includes the type and size of the wharf structure, the component material information includes the concrete strength, steel bar size and steel bar strength, and the ship information includes the maximum berthing ship mass and ship impact speed of the wharf design.

3. The method for evaluating the ship impact toughness of a high-pile dock according to claim 1, characterized in that: In S2, the displacement ductility ratio data set of the pile foundation of the high-piled pier under different ship masses and different impact speeds is obtained, including: Construct a finite element simulation model of a ship hitting a high-pile dock based on finite element analysis software; Assign corresponding material properties to the ship model and the dock model respectively; The embedded point method is used to simplify the pile-soil interaction. The energy transfer process of a ship colliding with a dock is simulated by explicit dynamic analysis method; The displacement ductility ratio dataset of the pile foundation of the high-piled pier under different ship masses and different impact velocities is obtained.

4. The method for evaluating the ship impact resistance of a high-pile dock according to claim 1, characterized in that: In S3, the corresponding relationship between the damage index and damage status of the pile foundation of the high-pile wharf is established, including: Obtain the curvature of the steel bar at equivalent yield and the curvature of the steel bar at the first yield, and calculate the equivalent yield strength displacement ductility ratio of the pile foundation of the high-pile wharf according to the curvature of the steel bar at equivalent yield and the curvature of the steel bar at the first yield; Obtain the equivalent height of the pile foundation, the diameter of the longitudinal steel bar and the standard value of the tensile strength of the longitudinal steel bar, and calculate the plastic hinge length of the pile foundation according to the equivalent height of the pile foundation, the diameter of the longitudinal steel bar and the standard value of the tensile strength of the longitudinal steel bar; Obtain the plastic hinge length of the pile foundation, and calculate the displacement ductility ratio under the preset concrete strain value by combining the preset concrete strain curvature, the curvature of the steel bar at equivalent yield, and the curvature of the steel bar at the first yield; Obtaining a maximum displacement ductility ratio under a preset concrete strain value according to the displacement ductility ratio under a preset concrete strain value; The displacement ductility ratio of the first steel bar yielding is obtained, and the damage index defined by the displacement ductility ratio of the pile foundation of the high-pile wharf is determined by combining the equivalent yield strength displacement ductility ratio of the pile foundation of the high-pile wharf, the displacement ductility ratio under the preset concrete strain value, and the maximum displacement ductility ratio under the preset concrete strain value.

5. The method for evaluating the toughness of a high-pile dock against ship impact according to claim 4, characterized in that: Obtaining the damage probability and exceedance probability of the high-pile dock under different damage states under different ship masses includes: Determine the probability distribution of the ship's pile speed; The pile velocity data set was randomly generated by Monte Carlo method; According to different ship mass conditions, the finite element explicit dynamic analysis is performed on the pile foundation velocity sample set to obtain the pile foundation displacement ductility ratio data set under different impact velocities; Based on the correspondence between the damage index and damage state of the pile foundation of the high-pile wharf, the damage probability under different damage states with different ship masses is calculated, and then the exceedance probability under different damage states with different ship masses is calculated.

6. The method for evaluating the ship impact resistance of a high-pile dock according to claim 5, characterized in that: The damage status includes five levels: basically intact, slightly damaged, moderately damaged, severely damaged and completely destroyed.

7. The method for evaluating the ship impact resistance of a high-pile dock according to claim 1, characterized in that: In S5, the recoverability analysis of the high-pile wharf includes: The failure probability of the high-pile pier is calculated based on the exceedance probability of different failure states, and the remaining function is calculated based on the function loss ratio of different failure states; Obtain the repair method corresponding to each damage state, and determine the repair time of the dock according to the repair method corresponding to each damage state; The repair time samples were established using triangular distribution, and the probability distribution of the repair time was obtained by normal distribution fitting.

8. The method for evaluating the toughness of a high-pile dock against ship impact according to claim 1, characterized in that: In S6, the high-pile wharf resilience evaluation index system based on different recovery functions is established, including: Select the recovery function model to describe the high-pile wharf function recovery process; The resilience index is calculated through the recovery function model; Resilience rating is performed based on resilience indicators.

9. The method for evaluating the toughness of a high-pile dock against ship impact according to claim 8, characterized in that: The recovery function includes any of the linear, exponential and triangular types, where The mathematical expression of the straight line is: ； The mathematical expression of exponential type is: ； The mathematical expression of the triangle is: ； In the formula, and are two constants fitted through the data, is the initial time of ship collision, is the ship collision time, For recovery time.

10. The method for evaluating the toughness of a high-pile dock against ship impact according to claim 8, characterized in that: The toughness evaluation indexes of high-pile docks under different ship masses and impact speeds include: Select the recovery function; The initial time of ship impact and the structural performance recovery time of the high-pile wharf are obtained, and the toughness index is calculated based on the recoverability curves corresponding to different damage states.

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