Assessment Method for the Impact Toughness of High-Piled Wharves against Ship Collisions

Abstract

The present invention discloses a method for evaluating the impact toughness of high-piled wharves, belonging to the technical field of port engineering. The method for evaluating the impact toughness of high-piled wharves includes: collecting information on high-piled wharves and ships; obtaining a data set of displacement ductility ratios of the pile foundations of high-piled wharves under the action of different impact velocities with different ship masses; establishing the corresponding relationship between the damage index and the damage state of the pile foundations of high-piled wharves; obtaining the damage probability and the exceedance probability of high-piled wharves under different damage states with different ship masses, and generating the vulnerability curve of high-piled wharves under different damage states; conducting the recoverability analysis of high-piled wharves; and establishing a toughness evaluation index system for high-piled wharves. The present invention scientifically reveals the vulnerability analysis of ships impacting high-piled wharves and the recoverability after impact from the perspective of probability theory, realizes the full-chain closed-loop analysis from impact process simulation, damage probability, and toughness quantitative evaluation, and improves the overall safety of high-piled wharves.

Description

Technical Field

[0001] The present invention relates to the technical field of port engineering, and particularly relates to a method for evaluating the anti-ship impact toughness of high-pile wharves. Background Art

[0002] As a main structural form of port construction, high-pile wharves are widely used in China's port engineering due to their advantages such as light self-weight, good wave-dissipating effect, and adaptability to soft soil foundations. However, during their entire life cycle, high-pile wharves are often threatened by extreme dynamic loads such as typhoons, earthquakes, and ship impacts. Especially with the increasing trend of ship enlargement, collision accidents of ship types beyond the code design occur frequently, making the dynamic response mechanism and damage evolution law of the wharf structure under impact loads become key safety issues.

[0003] Seismic toughness is defined as the ability of a building to maintain or restore its original building function after suffering from a specific level of earthquake action, and the seismic toughness index is a parameter used to evaluate the ability of a building to maintain or restore its original function under earthquake action. Currently, domestic and foreign research on structural toughness mainly focuses on the field of seismic toughness, and the research objects are mostly buildings and bridges. There is a serious lack of research on the structural toughness under ship impact loads, and the existing toughness evaluation system lacks differential analysis of different structural types, functions, and important buildings, making it difficult to accurately quantitatively evaluate the risks of ship-wharf collision accidents. Furthermore, it is difficult to guide the reinforcement design and maintenance decision-making of high-pile wharves by accurately predicting and analyzing the impact of impact loads on the wharf structure, affecting the overall safety of high-pile wharves. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention proposes a method for evaluating the anti-ship impact toughness of high-pile wharves, which can accurately quantitatively evaluate the risks of ship-wharf collision accidents, reduce disaster risks and operation and maintenance costs, improve the overall safety of high-pile wharves, and extend the service life of wharves.

[0005] According to an embodiment of the present invention, the method for evaluating the anti-ship impact toughness of high-pile wharves includes:

[0006] S1: Collect the structural design information, component material information, and ship information of the high-pile wharf;

[0007] S2: Establish a finite element simulation model of a ship impacting a high-pile wharf, use the finite element simulation model to simulate the ship collision process, and obtain a displacement ductility ratio dataset of the high-pile wharf piles under different impact speeds with different ship masses;

[0008] S3: Obtain the corresponding relationship between the pile foundation section moment and curvature, determine the critical values of the pile foundation under different failure states through the corresponding relationship between the pile foundation section moment and curvature, and combine the displacement ductility ratio dataset to establish the corresponding relationship between the pile foundation damage index and the damage state of the high-piled wharf;

[0009] S4: According to the corresponding relationship between the pile foundation damage index and the damage state of the high-piled wharf, obtain the damage probability and exceedance probability of the high-piled wharf under different damage states with different ship masses, and then generate the vulnerability curve of the high-piled wharf under different damage states;

[0010] S5: Conduct the recoverability analysis of the high-piled wharf according to different damage states of the high-piled wharf;

[0011] S6: By coupling the vulnerability curve and the results of the recoverability analysis, calculate the toughness evaluation index of the high-piled wharf based on different recovery functions to achieve the quantitative evaluation of the toughness level of the wharf structure under the ship impact condition.

[0012] The anti-ship impact toughness evaluation method of the high-piled wharf according to the embodiment of the present invention has at least the following beneficial effects: By integrating the structural parameters of the high-piled wharf and the ship characteristic data to construct a simulation model to analyze and simulate the whole process of ship impact, quantitatively obtain the dynamic response of the pile foundation, and then establish a probability statistical model based on the quantitative relationship between the damage index and the damage state, simulate the vulnerability curve of the high-piled wharf under different working conditions, and on this basis, carry out the recoverability analysis of the high-piled wharf by combining the damage state classification. Finally, by coupling the vulnerability analysis and the recoverability analysis, solve the toughness index of the ship impacting the high-piled wharf, scientifically reveal the vulnerability analysis of the ship impacting the high-piled wharf and the recoverability after impact from the perspective of probability theory, establish an anti-ship impact toughness evaluation method for the high-piled wharf, realize the full-chain closed-loop analysis from the impact process simulation, damage probability, and toughness quantitative evaluation, as well as the quantification of the dynamic damage of the ship impact on the wharf, and then realize the guidance for the reinforcement design and maintenance decision-making of the high-piled wharf, thereby reducing the disaster risk and operation and maintenance costs, extending the service life of the wharf, improving the overall safety of the high-piled wharf, and providing a theoretical reference for the toughness evaluation analysis of the high-piled wharf under the action of ship impact in the future.

[0013] According to some embodiments of the present invention, in S1, the structural design information includes the wharf structure type and structural dimensions, the component material information includes the concrete strength, steel bar dimensions, and steel bar strength, and the ship information includes the maximum berthing ship mass and ship impact speed designed for the wharf.

[0014] According to some embodiments of the present invention, in S2, obtaining the displacement ductility ratio data set of the high-piled wharf pile foundation under different impact velocities with different ship masses includes: constructing a finite element simulation model of a ship impacting a high-piled wharf based on finite element analysis software; respectively assigning corresponding material properties to the ship model and the wharf model; adopting the fixed-point method to equivalently simplify the pile-soil interaction; simulating the energy transfer process of the ship colliding with the wharf through the explicit dynamic analysis method; and obtaining the displacement ductility ratio data set of the high-piled wharf pile foundation under different impact velocities with different ship masses.

[0015] According to some embodiments of the present invention, in S3, establishing the correspondence between the damage index and the damage state of the high-piled wharf pile foundation includes: obtaining the curvature when the steel bar equivalently yields and the curvature when the steel bar first yields, and calculating the equivalent yield strength displacement ductility ratio of the high-piled wharf pile foundation based on the curvature when the steel bar equivalently yields and the curvature when the steel bar first yields; 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 based on 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 plastic hinge length of the pile foundation, and combining the preset concrete strain curvature, the curvature when the steel bar equivalently yields, and the curvature when the steel bar first yields to calculate the displacement ductility ratio under the preset concrete strain value; obtaining the maximum displacement ductility ratio under the preset concrete strain value based on the displacement ductility ratio under the preset concrete strain value; obtaining the displacement ductility ratio when the first steel bar yields, and combining the equivalent yield strength displacement ductility ratio of the high-piled wharf pile foundation, the displacement ductility ratio under the preset concrete strain value, and the maximum displacement ductility ratio under the preset concrete strain value to determine the damage index defined by the displacement ductility ratio of the high-piled wharf pile foundation.

[0016] According to some embodiments of the present invention, obtaining the damage probability and the exceedance probability of the high-piled wharf under different ship masses and different damage states includes: determining the probability distribution of the pile foundation velocity of the ship; randomly generating a data set of pile foundation velocities through the Monte Carlo method; for different ship mass conditions, performing finite element explicit dynamic analysis on the pile foundation velocity sample set to obtain the displacement ductility ratio data set of the pile foundation under different impact velocities; calculating the damage probability under different ship masses and different damage states based on the correspondence between the damage index and the damage state of the high-piled wharf pile foundation, and further calculating the exceedance probability under different ship masses and different damage states.

[0017] According to some embodiments of the present invention, the damage states include five levels: basically intact, slightly damaged, moderately damaged, severely damaged, and completely damaged.

[0018] According to some embodiments of the present invention, in S5, the recoverability analysis of the high-piled wharf includes: calculating the failure probability of the high-piled wharf based on the exceedance probability of different failure states, and calculating the remaining function by combining the functional loss ratio of different failure states; obtaining the repair methods corresponding to each damage state, and determining the repair time of the wharf according to the repair methods corresponding to each damage state; establishing a sample of the repair time by using a triangular distribution, and obtaining the probability distribution of the repair time through normal distribution fitting.

[0019] According to some embodiments of the present invention, in S6, establishing a resilience evaluation index system for the high-piled wharf based on different recovery functions includes: selecting a recovery function model to describe the functional recovery process of the high-piled wharf; calculating the resilience index through the recovery function model; and performing resilience evaluation according to the resilience index.

[0020] According to some embodiments of the present invention, the recovery function includes any one of a linear type, an exponential type, and a triangular type, where:

[0021] The mathematical expression of the linear type is:

[0022] ;

[0023] The mathematical expression of the exponential type is:

[0024] ;

[0025] The mathematical expression of the triangular type is:

[0026] ;

[0027] In the formula, and are two constants obtained by data fitting, is the initial time of ship impact, is the ship impact time, is the recovery time.

[0028] According to some embodiments of the present invention, determining the resilience evaluation index of the high-piled wharf under different ship masses and impact speeds includes: selecting a recovery function; obtaining the initial time of ship impact and the structural performance recovery time of the high-piled wharf, and calculating and obtaining the resilience index based on the recoverability curve corresponding to different failure states.

[0029] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become obvious from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0030] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0031] Figure 1 It is a schematic flow chart of the method for evaluating the anti-ship impact toughness of a high-pile wharf in this specific embodiment;

[0032] Figure 2 It is a value-taking diagram of ship impact speeds with 1000 groups subject to the extreme value type I distribution obtained by Monte Carlo sampling provided by an embodiment of the present invention;

[0033] Figure 3 It is a vulnerability curve diagram of a high-pile wharf under the action of ship impact provided by a specific embodiment of the present invention;

[0034] Figure 4 It is a failure probability curve diagram of a high-pile wharf under the action of ship impact provided by a specific embodiment of the present invention;

[0035] Figure 5 It is a recovery curve diagram of a high-pile wharf under the action of ship impact provided by a specific embodiment of the present invention. Specific embodiments

[0036] In the description of the present invention, it should be understood that for the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present invention.

[0037] In the description of the present invention, the meaning of "several" is one or more, the meaning of "multiple" is more than two, greater than, less than, exceeding, etc. are understood as not including the original number, and "above", "below", "within", etc. are understood as including the original number. If there is a description of "first", "second", etc., it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0038] In the description of the present invention, unless otherwise clearly defined, words such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0039] Please refer to Figures 1 to 5 , this embodiment discloses a method for evaluating the anti-ship impact toughness of a high-pile wharf, including:

[0040] S1: Collect the structural design information, component material information and ship information of the high-pile wharf;

[0041] S2: Establish a finite element simulation model for a high-piled wharf under ship impact. Use the finite element simulation model to simulate the ship collision process and obtain a dataset of displacement ductility ratios of the high-piled wharf pile foundation under different ship masses and different impact velocities.

[0042] S3: Obtain the corresponding relationship between the bending moment and curvature of the pile foundation cross-section. Determine the critical values of the pile foundation under different failure states through the corresponding relationship between the bending moment and curvature of the pile foundation cross-section. Combine the displacement ductility ratio dataset to establish the corresponding relationship between the damage index and damage state of the high-piled wharf pile foundation.

[0043] S4: According to the corresponding relationship between the damage index and damage state of the high-piled wharf pile foundation, obtain the damage probability and exceedance probability of the high-piled wharf under different ship masses and different damage states, and then generate the vulnerability curve of the high-piled wharf under different damage states.

[0044] S5: Conduct a recoverability analysis of the high-piled wharf according to different damage states of the high-piled wharf.

[0045] S6: By coupling the vulnerability curve and the results of the recoverability analysis, calculate the toughness evaluation index of the high-piled wharf based on different recovery functions to achieve a quantitative assessment of the toughness level of the wharf structure under ship impact conditions.

[0046] By integrating the structural parameters of the high-piled wharf and the ship characteristic data to construct a simulation model to analyze and simulate the whole process of ship impact, quantitatively obtain the dynamic response of the pile foundation, and then establish a probability statistical model based on the quantitative relationship between the damage index and the damage state to simulate the vulnerability curve of the high-piled wharf under different working conditions. On this basis, combine the damage state classification to conduct a recoverability analysis of the high-piled wharf. Finally, by coupling the vulnerability analysis and the recoverability analysis, solve the toughness index system of the ship impact on the high-piled wharf, thereby scientifically revealing the vulnerability analysis of the ship impact on the high-piled wharf and the recoverability after impact from the perspective of probability theory, establishing a method for evaluating the anti-ship impact toughness of the high-piled wharf, realizing a full-chain closed-loop analysis from the impact process simulation, damage probability, and toughness quantitative assessment, realizing the quantification of the dynamic damage of the ship impact on the wharf, and establishing a systematic toughness evaluation system to guide the reinforcement design and maintenance decision-making of the high-piled wharf, reduce the disaster risk and operation and maintenance costs, extend the service life of the wharf, improve the overall safety of the high-piled wharf, and provide a theoretical reference for the toughness evaluation and analysis of the high-piled wharf under ship impact in the future.

[0047] In some specific embodiments of the present invention, in S1, the structural design information includes the wharf structure type and structural dimensions, the component material information includes the concrete strength, steel bar dimensions, and steel bar strength, and the ship information includes the maximum ship mass that the wharf is designed to berth and the ship impact velocity.

[0048] In some specific embodiments of the present invention, in S2, obtaining the displacement ductility ratio dataset of the high-piled wharf pile foundation under different impact velocities with different ship masses includes: constructing a finite element simulation model of a ship impacting a high-piled wharf based on finite element analysis software; respectively assigning corresponding material properties to the ship model and the wharf model; using the fixed-point method to equivalently simplify the pile-soil interaction; simulating the energy transfer process of the ship colliding with the wharf through the explicit dynamic analysis method; obtaining the displacement ductility ratio dataset of the high-piled wharf pile foundation under different impact velocities with different ship masses.

[0049] In some specific embodiments of the present invention, in S3, establishing the correspondence between the damage index and the damage state of the high-piled wharf pile foundation includes:

[0050] S3.1: Obtain the curvature at the equivalent yield of the steel bar and the curvature at the first yield of the steel bar. Calculate and obtain the displacement ductility ratio of the equivalent yield strength of the high-piled wharf pile foundation according to the curvature at the equivalent yield of the steel bar and the curvature at the first yield of the steel bar. The specific calculation formula is as follows:

[0051] ;

[0052] In the formula, is the displacement ductility ratio of the equivalent yield strength of the high-piled wharf pile foundation, is the curvature at the equivalent yield of the steel bar; is the curvature at the first yield of the steel bar. It should be noted that the corresponding relationship between the bending moment and the curvature of the pile foundation section is determined by using the bending moment-curvature curve of the pile foundation section. and can be obtained through the analysis of 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 a conventional technical means, and its principle will not be further elaborated here.

[0053] S3.2: 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. Calculate and obtain 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. The specific calculation formula is as follows:

[0054] ;

[0055] In the formula, is the plastic hinge length, is the equivalent height of the pile foundation, is the diameter of the longitudinal steel bar, is the standard value of the tensile strength of the longitudinal steel bar.

[0056] S3.3: Obtain the plastic hinge length of the pile foundation. Combine the preset concrete strain curvature, the curvature at the equivalent yield of the steel bars, and the curvature at the first yield of the steel bars to calculate and obtain the displacement ductility ratio under the preset concrete strain value. The specific calculation formula is as follows:

[0057] ;

[0058] 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 when the concrete strain is 0.004, is the curvature at the equivalent yield of the steel bars, is the curvature at the first yield of the steel bars.

[0059] 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:

[0060] ;

[0061] In the formula, is the maximum displacement ductility ratio under the preset concrete strain value.

[0062] S3.5: Obtain the displacement ductility ratio at the first yield of the first steel bar. Combine the displacement ductility ratio at the equivalent yield strength of the pile foundation of the high-piled wharf, the displacement ductility ratio under the preset concrete strain value, and the maximum displacement ductility ratio under the preset concrete strain value to determine the damage index defined by the displacement ductility ratio of the pile foundation of the high-piled wharf.

[0063] In some specific embodiments of the present invention, obtaining the damage probability and the exceedance probability of the high-piled wharf in different damage states under different ship masses includes: determining the probability distribution of the pile foundation speed of the ship; randomly generating a pile foundation speed data set by the Monte Carlo method; for different ship mass conditions, performing a finite element explicit dynamic analysis on the pile foundation speed sample set to obtain a pile foundation displacement ductility ratio data set under different impact speeds; calculating the damage probability in different damage states under different ship masses based on the corresponding relationship between the pile foundation damage index of the high-piled wharf and the damage state, and then calculating and obtaining the exceedance probability in different damage states under different ship masses.

[0064] In some specific embodiments of the present invention, the damage states include five levels: basically intact, slightly damaged, moderately damaged, severely damaged, and completely damaged.

[0065] Specifically, the damage probability of the high-piled wharf in different damage states under different ship masses is calculated by the following formula:

[0066] ;

[0067] In the formula, ( i = 1, 2, 3, 4) are the damage probabilities of different ship masses in slight damage, medium damage, severe damage, and overall failure respectively, , , and are the data sets of slight damage, medium damage, severe damage, and overall failure that occur in n groups of ship impact simulations of different ship masses respectively, is the number of Monte Carlo sampling times.

[0068] After obtaining the damage probabilities of different ship masses in each damage state, the exceedance probability of the slight damage state is defined as the sum of the probabilities of the slight damage state, medium damage state, severe damage state, and overall failure state. The exceedance probability of the medium damage state is defined as the sum of the probabilities of the medium 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 overall failure state. The exceedance probability of the overall failure state is defined as the probability of the overall failure state.

[0069] That is, the exceedance probability of the slight damage state corresponding to different ship masses is: = ; the exceedance probability of the medium damage state is = ; the exceedance probability of the severe damage state is = ; the exceedance probability of the overall failure state is = .

[0070] In some specific embodiments of the present invention, in S5, the recoverability analysis of the high-pile wharf includes:

[0071] S5.1: Calculate the failure probability of the high-pile wharf based on the exceedance probability of different failure states. The failure probability of the high-pile wharf is calculated using the following formula:

[0072] ;

[0073] In the formula: is the failure probability of the wharf damage state being i under the action of a certain ship mass, is the exceedance probability of each failure state under the action of a certain ship mass, i is the number of failure states.

[0074] Calculate the remaining function by combining the function loss ratios in different damage states. The mathematical expression of the remaining function loss function is as follows:

[0075] ;

[0076] In the formula: represents the failure probability corresponding to the damage state i , is the function loss ratio corresponding to the damage state i , as shown in Table 1.

[0077] Table 1 Function loss ratio

[0078]

[0079] S5.2: Obtain the repair methods corresponding to each damage state, as shown in Table 2.

[0080] Table 2 Repair time of each plan

[0081]

[0082] Determine the repair time of the wharf according to the repair methods corresponding to each damage state, as shown in Table 3.

[0083] Table 3 Repair time of different damage states

[0084]

[0085] S5.3: Establish a repair time sample using the triangular distribution and obtain the probability distribution of the repair time through normal distribution fitting. It should be noted that due to the randomness of the wharf repair time, Table 3 is a triangular distribution based on Table 2, which is used to calculate the repair time required for different ship masses to impact the wharf. Specifically, based on the distribution of each damage state in Table 3, randomly sample a preset number of times that follows the triangular distribution and establish a sample of the repair time using the formula. Then, statistically analyze the sample to obtain the probability distribution of different repair times, and use normal distribution fitting to select the mean value as the repair time after the ship impact.

[0086] In some specific embodiments of the present invention, in S6, establishing a high-piled wharf toughness evaluation index system based on different recovery functions includes: selecting a recovery function model to describe the function recovery process of the high-piled wharf; calculating the toughness index through the recovery function model; and performing toughness evaluation according to the toughness index.

[0087] 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, where:

[0088] The mathematical expression of the linear type is:

[0089] ;

[0090] The exponential mathematical expression is:

[0091] ;

[0092] The triangular mathematical expression is:

[0093] ;

[0094] Wherein, and are two constants obtained by data fitting, is the initial time of ship impact, is the ship impact time, is the recovery time.

[0095] In some specific embodiments of the present invention, the toughness evaluation indexes of high-pile wharves under different ship masses and impact speeds are determined, including: selecting a recovery function; obtaining the initial time of ship impact and the recovery time of the structural performance of the high-pile wharf, and calculating and obtaining the toughness index based on the recoverability curves corresponding to different failure states. Specifically, the calculation formula of the toughness index is as follows:

[0096] ;

[0097] Wherein, is the toughness index, is the initial time of ship impact, is the recovery time of the structural performance of the high-pile wharf, is the structural function of the high-pile wharf.

[0098] Table 4 Toughness evaluation criteria

[0099]

[0100] In some specific embodiments of the present invention, the seismic toughness evaluation criteria shown in Figure 4 can be referred to for evaluation.

[0101] The following describes the anti-ship impact toughness evaluation method of the high-pile wharf according to a specific embodiment.

[0102] S1: Collect the structural design information, component material information and ship information of the high-pile wharf.

[0103] S2: Establish a finite element simulation model of the ship impacting the high-pile wharf, use the finite element simulation model to simulate the ship collision process, and obtain the displacement ductility ratio data set of the high-pile wharf pile foundation under different impact speeds with different ship masses.

[0104] In this example, the design information, material information, and ship information of the wharf structure in the finite element simulation model of ship impact on high-piled wharf adopt the parameters in Tables 5-7.

[0105] Table 5 Design Information of Wharf Structure

[0106]

[0107] Table 6 Material Information of Wharf Components

[0108]

[0109] Table 7 Ship Information

[0110]

[0111] In a specific embodiment of the present invention, the maximum berthing ship mass specified in the design of the high-piled wharf to be studied is 30,000 tons. Therefore, 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, 30,000 tons) in the example of the present invention under 1,000 sets of random impact speeds subject to the extreme value type I distribution is carried out. The ship impact speeds subject to the extreme value type I distribution are as Figure 2 shown.

[0112] It should be further noted that a large number of numerical analyses are carried out according to different ship masses and different ship impact speeds to be studied, so as to obtain the displacement ductility ratio of the high-piled wharf pile foundation under different impact speeds for different ship masses.

[0113] S3: Obtain the corresponding relationship between the pile foundation section moment and curvature, determine the critical values of the pile foundation under different failure states through the corresponding relationship between the pile foundation section moment and curvature, and establish the corresponding relationship between the pile foundation damage index and the damage state of the high-piled wharf in combination with the displacement ductility ratio data set.

[0114] It should be further noted that based on the performance-based pile foundation damage index, the displacement ductility ratio is selected as the wharf damage index, and combined with the curvature parameters obtained from the pile foundation section moment-curvature analysis, the critical values of the pile foundation in different failure states are calculated by combining formulas (1) to (4):

[0115] ;

[0116] In the formula, is the displacement ductility ratio of the equivalent yield strength of the high-piled wharf pile foundation, is the curvature when the steel bar yields equivalently, is the curvature when the steel bar first yields;

[0117] ;

[0118] 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 the tensile strength of the longitudinal reinforcement (MPa);

[0119] ;

[0120] 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 when the concrete strain is equal to 0.004, is the curvature when the reinforcement equivalently yields, is the curvature when the reinforcement first yields;

[0121] ;

[0122] 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.

[0123] In the 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.

[0124] Table 8 Damage Indexes Defined by the Displacement Ductility Ratio of the High-Pile Wharf Pile Foundation

[0125]

[0126] It should be noted that represents the displacement ductility ratio when the first reinforcement yields, and its value is 1.

[0127] S4: According to the corresponding relationship between the damage index of the high-pile wharf pile foundation and the damage state, obtain the damage probability and the exceedance probability of the high-pile wharf under different damage states for different ship masses, and then generate the vulnerability curve of the high-pile wharf under different damage states.

[0128] According to the corresponding relationship between the damage state and the damage index of the high-pile wharf in Table 8, calculate the damage probability of different ship masses under different damage states, where the damage probability is calculated by the following formula:

[0129] ；

[0130] In the formula, ( i = 1, 2, 3, 4) are the damage probabilities of different ship masses in the states of minor damage, moderate damage, severe damage, and overall failure, respectively. 、 、 and are the data sets of minor damage, moderate damage, severe damage, and overall failure that occurred in n sets of ship impact simulations of different ship masses, respectively. is the number of Monte Carlo sampling times. In this specific example, the random sampling times are 1000 times.

[0131] Before drawing the vulnerability curve, first obtain the damage probabilities of different ship masses in each damage state. The exceedance probability of the minor damage state is confirmed as the sum of the probabilities of the minor damage state, moderate damage state, severe damage state, and complete failure 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 overall failure state. The exceedance probability of the overall failure state is confirmed as the probability of the overall failure state.

[0132] That is, the exceedance probability of the minor damage state corresponding to different ship masses is: = ; the exceedance probability of the moderate damage state is = ; the exceedance probability of the severe damage state is = ; the exceedance probability of the complete failure state is = , and the exceedance probabilities of each damage state in this specific embodiment are calculated and obtained as shown in Table 9.

[0133] Table 9 Exceedance Probabilities of Each Damage State

[0134]

[0135] According to the relationship between different ship masses and the exceedance probabilities of the damage states of high-pile wharves, draw the vulnerability curves of the wharves in different damage states, as shown in Figure 3 .

[0136] S5: Conduct a recoverability analysis of the high-pile wharf according to different damage states of the high-pile wharf.

[0137] It should be noted that the remaining function of the ship impacting the high-pile wharf is directly related to its degree of damage. Based on the exceedance probabilities of the vulnerability of different damage states, the damage probability of the high-pile wharf is solved by combining the following formula:

[0138] ;

[0139] Wherein, is the failure probability of the pier damage state under the action of a certain ship mass being i , is the exceeding probability of each failure state under the action of a certain ship mass, i is the number of failure states. The solution results of this specific embodiment are as Figure 4 shown.

[0140] Combined with the functional loss ratio of different failure states, calculate the remaining function of the ship impacting the high-pile pier. The mathematical expression of the remaining function loss function is:

[0141] ;

[0142] Wherein, represents the failure probability corresponding to the damage state i , is the functional loss ratio corresponding to the damage state i . The solution results of this specific embodiment are shown in Table 10.

[0143] Table 10 Functional loss ratio

[0144]

[0145] Referring to Table 11 and Table 12, to determine the repair time of the high-pile pier, it is necessary to determine the repair method of the pier in each damage state. Calculate the repair time based on the damage probability of different failure states of the high-pile pier. The specific calculation formula is as follows:

[0146] ;

[0147] Wherein, is the repair time of the high-pile pier, represents the failure probability corresponding to the damage state i , is the repair time corresponding to the damage state i .

[0148] Table 11 Repair time of each scheme

[0149]

[0150] The repair time is affected by many factors such as the repair method, the degree of structural damage, and material reserves, and there is a certain degree of uncertainty. Therefore, the repair time adopts a triangular distribution form, as shown in Table 12.

[0151] Table 12 Repair time of different damage states

[0152]

[0153] Based on the distribution of each damage state in Table 12, 1000 random samplings obeying the triangular distribution are carried out, and samples of repair time are established by combining with the formula. Then, the probability distribution of different repair times is obtained by statistically analyzing the samples, and the normal distribution is used for fitting. The mean value is selected as the repair time after ship impact. The results of this specific embodiment are as Figure 5 shown.

[0154] S6: By coupling the vulnerability curve and the recoverability analysis results, calculate the resilience evaluation index of the high-piled wharf based on different recovery functions to achieve the quantitative evaluation of the resilience level of the wharf structure under the ship impact condition.

[0155] The recovery function is mainly used to describe the repair method after the ship impacts the high-piled wharf. One of the empirical function recovery functions of linear type, exponential type, and triangular type is used for the recoverability evaluation standard. The mathematical expressions of the three empirical function recovery functions are as follows:

[0156] The mathematical expression of the linear type is:

[0157] ;

[0158] The mathematical expression of the exponential type is:

[0159] ;

[0160] The mathematical expression of the triangular type is:

[0161] ;

[0162] In the formula, and are two constants obtained by data fitting, is the initial time of ship impact, is the ship impact time, is the recovery time.

[0163] Based on the above vulnerability curve and the recoverable curve corresponding to different damage states, the resilience index of the high-piled wharf under different damage states can be obtained. It should be further noted that the linear recovery function is applicable to minor or moderate damage, the repair process does not require complex adjustment, the wharf repair resources are stable, the repair time requirements are predictable and there is no urgent need, allowing linear progress; the exponential recovery function is for the wharf to restore key functions in a short period, such as the port navigation capacity, with intensive resource input and non-linear acceleration requirements for the repair progress, and quickly restores the basic functions of the wharf through emergency repair; the triangular recovery function is applicable to the situation where the damage of large wharf structures is relatively serious, its repair resource response is relatively slow, and the repair process requires prioritization.

[0164] Specifically, the ductility index of the high-piled wharf structure is calculated from the recoverability curve T corresponding to different failure states, and the following formula is used to calculate the ductility index:

[0165] ;

[0166] In the formula, is the ductility index, is the initial time of ship impact, is the recovery time of the high-piled wharf structure performance, is the structural performance function of the high-piled wharf;

[0167] ;

[0168] In the formula, is the function loss function, is the different function recovery functions, is the structural performance function of the high-piled wharf.

[0169] It should be further noted that this specific embodiment is evaluated with reference to the seismic ductility evaluation standard and according to Table 4.

[0170] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge scope of those of ordinary skill in the art.

Claims

1. A method for evaluating the anti-ship impact toughness of a high-piled wharf, characterized in that, Including: S1: Collect the structural design information, component material information, and ship information of the high-piled wharf; S2: Establish a finite element simulation model of a ship impacting a high-piled wharf, use the finite element simulation model to simulate the ship collision process, and obtain a data set of the displacement ductility ratios of the high-piled wharf pile foundation under different impact speeds with different ship masses; S3: Obtain the corresponding relationship between the pile foundation section moment and curvature, determine the critical values of the pile foundation under different failure states through the corresponding relationship between the pile foundation section moment and curvature, and establish the corresponding relationship between the high-piled wharf pile foundation damage index and the damage state in combination with the displacement ductility ratio data set; Establishing the corresponding relationship between the high-piled wharf pile foundation damage index and the damage state includes: Obtain the curvature when the steel bar is equivalent to yield and the curvature when the steel bar first yields, and calculate the displacement ductility ratio of the equivalent yield strength of the high-piled wharf pile foundation according to the curvature when the steel bar is equivalent to yield and the curvature when the steel bar first yields; 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 in combination with the preset concrete strain curvature, the curvature when the steel bar is equivalent to yield, and the curvature when the steel bar first yields; Obtain the maximum displacement ductility ratio under the preset concrete strain value according to the displacement ductility ratio under the preset concrete strain value; Obtain the displacement ductility ratio when the first steel bar yields, and determine the damage index defined by the displacement ductility ratio of the high-piled wharf pile foundation in combination with the displacement ductility ratio of the equivalent yield strength of the high-piled wharf pile foundation, the displacement ductility ratio under the preset concrete strain value, and the maximum displacement ductility ratio under the preset concrete strain value; S4: According to the corresponding relationship between the high-piled wharf pile foundation damage index and the damage state, obtain the damage probability and exceedance probability of the high-piled wharf under different damage states with different ship masses, and then generate the vulnerability curve of the high-piled wharf under different damage states; S5: Conduct a recoverability analysis of the high-piled wharf according to different damage states of the high-piled wharf; Conducting a recoverability analysis of the high-piled wharf includes: Calculate the failure probability of the high-piled wharf based on the exceedance probability of different failure states, and calculate the remaining function in combination with the functional loss ratio of different failure states; Obtain the repair methods corresponding to each damage state, and determine the repair time of the wharf according to the repair methods corresponding to each damage state; Establish a repair time sample using a triangular distribution, and obtain the probability distribution of the repair time through normal distribution fitting; S6: By coupling the vulnerability curve and the results of the recoverability analysis, calculate the high-piled wharf toughness evaluation index based on different recovery functions to achieve a quantitative assessment of the toughness level of the wharf structure under the ship impact condition.

2. The method for evaluating the impact toughness of a high-piled wharf according to claim 1, wherein, In S1, the structural design information includes the wharf structure type and structural dimensions, the component material information includes the concrete strength, steel bar dimensions, and steel bar strength, and the ship information includes the ship mass and ship impact speed of the maximum berthing designed for the wharf.

3. The method for evaluating the anti-ship impact toughness of a high-piled wharf according to claim 1, characterized in that, In S2, obtaining the data set of the displacement ductility ratios of the high-piled wharf pile foundation under different impact speeds with different ship masses includes: Build a finite element simulation model of a high-piled wharf impacted by a ship based on finite element analysis software; Assign corresponding material properties to the ship model and the wharf model respectively; Adopt the fixed-point method to equivalently simplify the pile-soil interaction; Simulate the energy transfer process of the ship colliding with the wharf by the explicit dynamic analysis method; Obtain a data set of the displacement ductility ratio of the high-piled wharf piles under different impact velocities with different ship masses.

4. The method for evaluating the anti-ship impact toughness of a high-piled wharf according to claim 1, wherein, Obtain the damage probability and exceedance probability of the high-piled wharf under different damage states with different ship masses, including: Determine the probability distribution of the pile foundation velocity of the ship; Randomly generate a data set of pile foundation velocities by the Monte Carlo method; For different ship mass conditions, conduct finite element explicit dynamic analysis on the pile foundation velocity sample set to obtain a data set of the displacement ductility ratio of the pile foundation under different impact velocities; Calculate the damage probability under different damage states with different ship masses based on the corresponding relationship between the damage index of the high-piled wharf pile foundation and the damage state, and then calculate and obtain the exceedance probability under different damage states with different ship masses.

5. The method for evaluating the anti-ship impact toughness of a high-piled wharf according to claim 4, characterized in that, The damage states include five levels: basically intact, slightly damaged, moderately damaged, severely damaged, and completely damaged.

6. The method for evaluating the anti-ship impact toughness of a high-piled wharf according to claim 1, characterized in that, In S6, establish a toughness evaluation index system for high-piled wharves based on different recovery functions, including: Select a recovery function model to describe the functional recovery process of the high-piled wharf; Calculate the toughness index through the recovery function model; Conduct toughness rating according to the toughness index.

7. The method for evaluating the anti-ship impact toughness of a high-piled wharf according to claim 6, characterized in that, The recovery function includes any one of the linear type, exponential type, and triangular type, where The mathematical expression of the linear type is: ； The mathematical expression of the exponential type is: ； The mathematical expression of the triangular type is: ； In the formula, and are two constants obtained by data fitting, is the initial time of ship impact, is the ship impact time, is the recovery time.

8. The method for evaluating the anti-ship impact toughness of a high-piled wharf according to claim 6, characterized in that, Determine the toughness evaluation index of the high-piled wharf under different ship masses and impact velocities, including: Select a recovery function; Obtain the initial time of ship impact and the structural performance recovery time of the high-piled wharf, and calculate and obtain the toughness index based on the recoverability curve corresponding to different damage states.

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