Seismic fragility analysis of precast concrete structures subjected to coupled blast and earthquake loads

Abstract

The present application relates to the field of building industrialization intelligent construction and disaster prevention and mitigation, in particular to a method for calculating the vulnerability of fabricated concrete structures under the action of earthquakes and explosions. The present application defines the damage state of the whole fabricated concrete structure under the combined action of earthquakes and explosions, and proposes a method for calculating the probability vulnerability of fabricated concrete structures under the combined action of earthquakes and explosions, which reveals the failure probability of fabricated concrete structures under the combined action of earthquakes and explosions.

Description

Technical Field

[0001] This invention relates to the fields of industrialized intelligent construction and disaster prevention and mitigation, specifically a method for calculating the vulnerability of prefabricated concrete structures under the coupled effects of earthquakes and explosions. Background Technology

[0002] Prefabricated concrete structures have been widely promoted and applied in the construction industry due to their advantages such as high construction efficiency, energy saving, and environmental protection. However, these structures may face the individual or coupled effects of various extreme disasters such as earthquakes and explosions throughout their entire life cycle. Although the probability of earthquakes and explosions occurring simultaneously is low, once they do, the secondary disaster effects caused by factors such as gas pipeline explosions after earthquakes may exacerbate the original damage to the structure, or even lead to severe structural failure or cascading collapse. Therefore, accurately assessing the disaster resistance performance of prefabricated concrete structures under the coupled effects of multiple disasters is of significant engineering practical importance.

[0003] However, current vulnerability analyses of concrete structures are usually based on single-hazard actions. Studies involving the combined effects of earthquakes and explosions are mostly based on empirical judgments of typical working conditions. There is a lack of a universal probabilistic assessment method to comprehensively reflect the overall structural damage state after the combined effects of the two hazards. It is impossible to reveal how the initial damage caused by the earthquake exacerbates the probability of structural failure under subsequent explosions. Therefore, this issue urgently needs to be addressed. Summary of the Invention

[0004] To avoid and overcome the technical problems existing in the prior art, this invention provides a method for calculating the vulnerability of prefabricated concrete structures under the coupled effects of earthquakes and explosions. This invention defines the overall damage state of prefabricated concrete structures under the combined effects of earthquakes and explosions, and proposes a probabilistic vulnerability calculation method for prefabricated concrete structures that simultaneously considers the coupled effects of earthquakes and explosions, revealing the failure probability of prefabricated concrete structures under dual-hazard conditions.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for calculating the vulnerability of prefabricated concrete structures under earthquake-blast coupling effects includes the following steps: S1. Establish a nonlinear finite element model of the prefabricated concrete frame structure; S2. Apply seismic loads and perform finite element analysis of the seismic stand-alone load case to obtain sample responses; S3. Perform failure judgment on the samples that have completed the seismic analysis. Include the samples that have reached the failure threshold in the failure sample set and terminate the subsequent calculation. Apply explosive load to the samples that have not reached the failure threshold with the final state of the seismic analysis as the initial condition, establish a combined seismic and explosive action model, carry out the combined seismic and explosive action, and obtain the response samples of the prefabricated concrete structure under the combined action. S4. Construct a structural performance demand function under multiple disasters, and perform regression analysis based on response samples to determine the undetermined coefficients of the structural performance demand function; S5. Based on the structural performance level, damage states are classified. Combined with the structural performance demand function, a multi-hazard vulnerability function is constructed, a joint vulnerability curve is plotted, and the probability of structural damage under different combinations of earthquake and explosion intensities is evaluated.

[0006] As a further aspect of the present invention: In S5, the multi-hazard vulnerability function is... P :

[0007] in, P This represents the conditional exceedance probability of a structure under the coupled effects of earthquake and explosion. Φ It is the standard normal distribution function; Structural performance requirements under multiple disasters; θ c These are the control indicator limits for each stage of the structure; The standard deviation of the log-normal distribution of structural disaster resistance performance requirements; μ C The standard deviation of disaster prevention capability.

[0008] As a further aspect of the present invention: In S4, the structural performance demand function under multiple disasters is: :

[0009] in, a, b, c All are undetermined coefficients; IM 1 Indicates the intensity of earthquake damage; IM 2 Indicates the intensity of the explosion hazard.

[0010] As a further aspect of the present invention, the intensity of earthquake disaster and the intensity of explosion disaster are characterized by peak ground acceleration and explosion ratio distance, respectively.

[0011] As a further aspect of the present invention: regression analysis is performed based on response samples. a = -9.83031; b =0.66089; c=﹣4.86142.

[0012] As a further aspect of this invention: the residuals reflect the dispersion of the non-systematic response of the structure under earthquake-blast coupled loading. When the residuals follow a normal distribution with a mean of zero in the logarithmic domain, the standard deviation of the log-normal distribution of the performance requirements of the demand structure under the two disasters is determined by the unbiased estimator of the residual variance. ;

[0013] in, Indicates the first i Earthquake disaster intensity level; Indicates the first j Level of explosion hazard intensity; Indicates based on the first i Earthquake disaster intensity level and the first j Structural performance requirements under the influence of a Class I explosion hazard intensity level; Since there are three groups of undetermined coefficients, the unbiased estimate of the residual variance is adopted. n-3 The degree of freedom is modified.

[0014] Since there are three groups of undetermined coefficients, the unbiased estimate of the residual variance is adopted. n-3 The degree of freedom is modified.

[0015] An electronic device includes a processor, an input device, an output device, and a memory, wherein the processor, input device, output device, and memory are connected in sequence, the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions to execute the aforementioned method for calculating the vulnerability of prefabricated concrete structures under seismic-explosion coupling.

[0016] A readable storage medium storing a computer program, the computer program including program instructions that, when executed by a processor, cause the processor to perform the aforementioned method for calculating the vulnerability of prefabricated concrete structures under seismic-explosion coupling.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention establishes a nonlinear finite element model of a prefabricated concrete frame structure and adopts a simulation strategy of sequential combined seismic and explosive effects. It establishes a loading regime that applies explosive loads based on the final state of the seismic analysis as the initial condition, constructs a probabilistic vulnerability performance requirement function for prefabricated concrete structures that can simultaneously consider the coupled effects of seismic and explosive effects, and establishes the criteria for determining the dual-hazard damage index and performance level classification of concrete structures under the coupled effects of seismic and explosive effects. This invention truly reflects the deterioration effect of seismic damage on the subsequent blast resistance of the structure, fully considers the influence of the initial damage caused by the earthquake on the explosive response, and makes the vulnerability analysis results closer to the actual disaster scenario. It can analyze the overall damage state of the concrete structure based on the combined effects of seismic and explosive effects, and reveals the failure probability of the structure under dual-hazard effects.

[0018] 2. This invention performs failure assessment on each sample that has completed seismic analysis. Samples that reach the failure threshold are included in the failure sample set and subsequent calculations are terminated. Only samples that have not reached the failure threshold are subjected to explosive loads for combined action simulation. This selective simulation strategy of assessment first and calculation later avoids redundant explosive analysis on structural samples that have already failed during the seismic phase, significantly reduces the amount of finite element calculations, and improves the efficiency of vulnerability analysis of concrete structures under multiple disasters.

[0019] 3. Before conducting the simulation of the combined effects of earthquake and explosion, this invention performs finite element analysis on the seismic and explosion-only action conditions to obtain response samples under single-hazard action. The single-hazard vulnerability curve can serve as a benchmark for comparing the vulnerability of multiple hazards, and can quantify the amplification effect of coupling on the failure probability, providing a more accurate calculation method for the damage assessment of structures under multiple hazard action. Attached Figure Description

[0020] Figure 1 This is a vulnerability analysis diagram of the structure when the support rotation angle is 1° in this invention.

[0021] Figure 2 This is a vulnerability analysis diagram of the structure when the support rotation angle is 3° in this invention.

[0022] Figure 3 This is a vulnerability analysis diagram of the structure when the support rotation angle is 6° in this invention.

[0023] Figure 4 This is a comparative analysis of vulnerability under the coupled action of earthquake and explosion versus the action of a single explosion, based on PGA=0.2g.

[0024] Figure 5 This is a comparative analysis of vulnerability under the coupled action of earthquake and explosion versus the action of a single explosion, based on PGA=0.4g.

[0025] Figure 6 This is a schematic diagram of the structural performance requirement model in this invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Please see Figures 1-6 In this embodiment of the invention, the method for calculating the vulnerability of prefabricated concrete structures under earthquake-blast coupling includes the following steps: S1. Establish a nonlinear finite element model of the prefabricated concrete frame structure; S2. Apply seismic loads and perform finite element analysis of the seismic stand-alone load case to obtain sample responses; S3. Perform failure judgment on the samples that have completed the seismic analysis. Include the samples that have reached the failure threshold in the failure sample set and terminate the subsequent calculation. Apply explosive load to the samples that have not reached the failure threshold with the final state of the seismic analysis as the initial condition, establish a combined seismic and explosive action model, perform dynamic response of combined seismic and explosive action, and obtain response samples of prefabricated concrete structures under combined action. S4. Construct the structural performance requirement function under multiple disasters. Regression analysis was performed based on the response samples to determine the undetermined coefficients of the structural performance demand function. a, b, c ;

[0028] in, a, b, c All are undetermined coefficients; IM 1 The intensity of earthquake damage is represented by peak ground acceleration. IM 2 The intensity of an explosion hazard is represented by the explosion-proportional distance. Regression analysis based on response samples, such as Figure 6 As shown, analysis reveals that, a = -9.83031; b =0.66089; c =﹣4.86142.

[0029] S5. Based on the structural performance level, damage states are classified. Combined with the structural performance demand function, a multi-hazard vulnerability function is constructed, a joint vulnerability curve is plotted, and the probability of structural damage under different combinations of earthquake and explosion intensities is evaluated.

[0030] The multi-hazard vulnerability function is P :

[0031] in, P This represents the conditional exceedance probability of a structure under the coupled effects of earthquake and explosion. Φ It is the standard normal distribution function; Structural performance requirements under multiple disasters; θ c These are the control indicator limits for each stage of the structure; The maximum inter-story drift angle under different failure states is used as the performance level of the structure. The failure states of prefabricated concrete frame structures are divided into five stages: basically intact (Ⅰ), slightly damaged (Ⅱ), moderately damaged (Ⅲ), severely damaged (Ⅳ) and collapsed (Ⅴ). Each stage corresponds to a specific inter-story drift angle limit. In the basically intact stage, the maximum inter-story drift angle is <0.002; in the slightly damaged stage, the maximum inter-story drift angle ranges from 0.002 to 0.005; in the moderately damaged stage, the maximum inter-story drift angle ranges from 0.005 to 0.01; in the severely damaged stage, the maximum inter-story drift angle ranges from 0.01 to 0.02; and in the collapse stage, the maximum inter-story drift angle is >0.02.

[0032] The performance level of the structure is determined by the support rotation angle under different failure states. The failure states are divided into four stages: minor damage (Ⅰ), moderate damage (Ⅱ), severe damage (Ⅲ) and complete damage (Ⅳ). Each level corresponds to a specific support rotation angle limit.

[0033] by θ B For the support rotation angle, in the stage of minor damage, 0 < θ B ≤1°; moderate injury stage, 1° < θ B ≤3°; in the severe injury stage, 3° < θ B ≤6°; complete damage stage, 6° < θ B .

[0034] The standard deviation of the log-normal distribution of structural disaster resistance performance requirements; The residuals reflect the dispersion of the non-systematic response of the structure under seismic-blast coupled loading. When the residuals follow a normal distribution with zero mean in the logarithmic domain, the standard deviation of the log-normal distribution of the performance requirements of the demand structure under the two disasters is determined by the unbiased estimator of the residual variance. ;

[0035] in, Indicates the first i Earthquake disaster intensity level; Indicates the first j Level of explosion hazard intensity; Indicates based on the first i Earthquake disaster intensity level and the first j Structural performance requirements under the influence of a Class I explosion hazard intensity level; Since there are three groups of undetermined coefficients, the unbiased estimate of the residual variance is adopted. n-3 The degree of freedom is modified.

[0036] μ C The logarithmic standard deviation of disaster prevention capability is used to quantify the inherent uncertainty of the structure's own bearing capacity due to factors such as material performance dispersion, geometric dimension deviation, construction quality fluctuation and constitutive model simplification. Its value ranges from 0.25 to 0.4, and is preferably 0.3 in this embodiment.

[0037] like Figures 1-3 As shown, when the support rotation angle is 1°, 3° and 6°, under the action of earthquake only, the structure increases with the increase of disaster intensity when subjected to different earthquake intensities.

[0038] like Figure 4 As shown, a comparative analysis of the vulnerability of multiple disasters (earthquake (PGA=0.2g)-explosion) and single disaster (explosion) shows that the trend of vulnerability curve changes is consistent with the pattern under the action of a single disaster, both showing the characteristic of increasing with the increase of disaster intensity.

[0039] like Figure 5 As shown, a comparative analysis of the vulnerability of multiple disasters (earthquake (PGA=0.4g)-explosion) and single disaster (explosion) shows that the trend of vulnerability curve changes is consistent with the pattern under the action of a single disaster, both showing the characteristic of increasing with the increase of disaster intensity.

[0040] Compared to explosive forces, the failure probability of structures suffering minor, moderate, and severe damage under multiple disaster conditions increases with earthquake intensity. PGA The increase shows a clear upward trend; when PGA=0.2g and explosive strength Z =0.24m / kg 1 / 3 When the structure experiences minor, moderate, severe, and complete damage, the failure probabilities of these three adjacent limit states are 96.34%, 22.91%, and 1%, respectively; while when... PGA Increased to 0.4g ( Z= 0.24m / kg 1 / 3 When the seismic intensity remains constant, the corresponding limit state failure probabilities of the structure are 99.78%, 62.32%, and 9.85%, respectively. The results show that seismic intensity has a significant amplification effect on secondary damage to the structure.

[0041] Another embodiment of this application is an electronic device.

[0042] The electronic device can be the mobile device itself, or a standalone device that can communicate with the mobile device to receive the collected input signals from it and send the selected target decision behavior to it.

[0043] Electronic devices include one or more processors and memory.

[0044] A processor can be a central processing unit (CPU) or other form of processing unit with data processing and / or instruction execution capabilities, and can control other components in an electronic device to perform desired functions.

[0045] The memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and a processor may execute the program instructions to implement the multi-hazard vulnerability calculation method for prefabricated concrete structures considering the coupling effect of earthquakes and explosions described in the various embodiments of this application above.

[0046] In one example, the electronic device may also include input and output devices, which are interconnected via a bus system and / or other forms of connection. For example, the input device may include various devices such as on-board diagnostics (OBD), cameras, industrial cameras, etc. The input device may also include, for example, a keyboard, a mouse, etc. The output device may include, for example, a monitor, speakers, a printer, and communication networks and their connected remote output devices, etc.

[0047] In addition, depending on the specific application, electronic devices may include any other suitable components.

[0048] Another embodiment of this application may be a computer program product, which includes computer program instructions that, when executed by a processor, cause the processor to perform the calculation steps described in the above-described method for calculating the multi-hazard vulnerability of prefabricated concrete structures considering the coupling effect of earthquakes and explosions, according to various embodiments of this application.

[0049] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this application. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0050] Furthermore, embodiments of this application may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to execute a method for calculating the multi-hazard vulnerability of prefabricated concrete structures considering the coupling effect of earthquakes and explosions, as described in this specification.

[0051] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may, for example, include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0052] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0053] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

Claims

1. A method for calculating the vulnerability of prefabricated concrete structures under seismic-blast coupling, characterized in that, Includes the following steps: S1. Establish a nonlinear finite element model of the prefabricated concrete frame structure; S2. Apply seismic loads and perform finite element analysis of the seismic stand-alone load case to obtain sample responses; S3. Perform failure judgment on the samples that have completed the seismic analysis. Include the samples that have reached the failure threshold in the failure sample set and terminate the subsequent calculation. Apply explosive load to the samples that have not reached the failure threshold with the final state of the seismic analysis as the initial condition, establish a combined seismic and explosive action model, perform dynamic response of combined seismic and explosive action, and obtain response samples of prefabricated concrete structures under combined action. S4. Construct a structural performance demand function under multiple disasters, and perform regression analysis based on response samples to determine the undetermined coefficients of the structural performance demand function; S5. Based on the structural performance level, damage states are classified. Combined with the structural performance demand function, a multi-hazard vulnerability function is constructed, a joint vulnerability curve is plotted, and the probability of structural damage under different combinations of earthquake and explosion intensities is evaluated.

2. The method for calculating the vulnerability of prefabricated concrete structures under seismic-explosive coupling action according to claim 1, characterized in that, In S5, the multi-hazard vulnerability function is: P : in, P This represents the conditional exceedance probability of a structure under the coupled effects of earthquake and explosion. Φ It is the standard normal distribution function; Structural performance requirements under multiple disasters; θ c These are the control indicator limits for each stage of the structure; The standard deviation of the log-normal distribution of structural disaster resistance performance requirements; μ C The standard deviation of disaster prevention capability.

3. The method for calculating the vulnerability of prefabricated concrete structures under seismic-explosive coupling action according to claim 2, characterized in that, In S4, the structural performance requirement function under multiple disasters is: : in, a, b, c All are undetermined coefficients; IM 1 Indicates the intensity of earthquake damage; IM 2 Indicates the intensity of the explosion hazard.

4. The method for calculating the vulnerability of prefabricated concrete structures under seismic-explosive coupling action according to claim 3, characterized in that, Peak ground acceleration and explosion-proportional distance are used to characterize the intensity of earthquake disasters and explosion disasters, respectively.

5. The method for calculating the vulnerability of prefabricated concrete structures under seismic-explosive coupling action according to claim 3, characterized in that, Regression analysis based on response samples a ＝﹣9.83031； b =0.66089； c =﹣4.86142。 6. The method for calculating the vulnerability of prefabricated concrete structures under seismic-explosive coupling action according to claim 2, characterized in that, The residuals reflect the dispersion of the non-systematic response of the structure under seismic-blast coupled loading. When the residuals follow a normal distribution with zero mean in the logarithmic domain, the standard deviation of the log-normal distribution of the performance requirements of the demand structure under the two disasters is determined by the unbiased estimator of the residual variance. ; in, Indicates the first i Earthquake disaster intensity level; Indicates the first j Level of explosion hazard intensity; Indicates based on the first i Earthquake disaster intensity level and the first j Structural performance requirements under the influence of a Class I explosion hazard intensity level; Since there are three groups of undetermined coefficients, the unbiased estimate of the residual variance is adopted. n-3 The degree of freedom is modified.

7. An electronic device, characterized in that, The system includes a processor, an input device, an output device, and a memory, which are connected in sequence. The memory is used to store a computer program, which includes program instructions. The processor is configured to call the program instructions to execute the method for calculating the vulnerability of prefabricated concrete structures under earthquake-blast coupling as described in any one of claims 1 to 6.

8. A readable storage medium, characterized in that, The storage medium stores a computer program, which includes program instructions that, when executed by a processor, cause the processor to perform a method for calculating the vulnerability of prefabricated concrete structures under seismic-explosion coupling as described in any one of claims 1 to 6.

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