A quantitative evaluation method and system for the ultimate seismic resistance of gravity dams

Abstract

This invention discloses a quantitative evaluation method for the ultimate seismic resistance capacity of gravity dams, comprising: S1, constructing a finite element analysis model of the gravity dam-foundation system that simultaneously considers strength and stability failure; S2, using incremental dynamic analysis to scale the design earthquake to different seismic intensity levels; S3, conducting multiple sets of nonlinear dynamic response analyses to obtain the strong earthquake response results of the gravity dam-foundation system; S4, based on the response results, constructing evaluation indices characterizing the seismic performance of the gravity dam-foundation system; S5, constructing line graphs showing the variation of different performance evaluation indices with different scaling factors, and determining the ultimate seismic resistance capacity of the gravity dam based on the scaling factor corresponding to the maximum slope in the line graphs. This method represents a shift in the seismic safety evaluation of gravity dam-foundation systems from a single failure mode and single index to a comprehensive consideration of multiple failure modes and multiple evaluation indices, reflecting the synergistic effect of multiple failure mechanisms in actual engineering projects, and providing a theoretical basis for seismic safety assessment and risk management.

Description

Technical Field

[0001] This invention belongs to the field of gravity dam seismic evaluation technology, specifically relating to a quantitative evaluation method and system for the ultimate seismic resistance capacity of gravity dams. Background Technology

[0002] Seismic safety evaluation of gravity dams includes both dam strength safety evaluation and overall anti-sliding stability safety evaluation. Current seismic codes stipulate that the seismic safety evaluation of gravity dams is based on static and dynamic analysis results using materials mechanics methods, while the overall stability of the dam is based on the rigid body limit equilibrium method. For gravity dams classified as Class A seismic fortification, the finite element method should be considered for calculation. Therefore, in current seismic codes, strength and stability are considered separately. However, in actual dams under strong earthquakes, the sliding of the sliding blocks may lead to the release and transfer of seismic energy, mitigating dam damage and cracking; conversely, dam damage and cracking will also affect the sliding of the sliding blocks. Furthermore, most existing studies on the seismic safety evaluation of gravity dams rely on macroscopic judgments of whether through-cracks appear at the dam head or whether yielding occurs on the sliding surface. Few studies quantitatively and comprehensively evaluate the seismic safety of dams by considering multiple failure mode indicators.

[0003] Therefore, it is necessary to conduct nonlinear dynamic response analysis by simultaneously considering both strength and stability failure modes, and to propose performance evaluation indicators and corresponding quantitative evaluation criteria that are more in line with actual conditions. Summary of the Invention

[0004] To address the aforementioned shortcomings in existing technologies, this invention provides a quantitative evaluation method and system for the ultimate seismic resistance capacity of gravity dams. This solves the problem that existing methods for evaluating the seismic resistance capacity of gravity dams separate the analysis of strength and stability, thus failing to accurately and quantitatively evaluate the ultimate seismic resistance capacity of gravity dams.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is: a quantitative evaluation method for the ultimate seismic resistance capacity of gravity dams, comprising the following steps:

[0006] S1. Based on the location of the weak structural layer of the gravity dam to be evaluated, construct a finite element analysis model of the gravity dam-foundation system that simultaneously considers strength and stability failure.

[0007] S2. The incremental dynamic analysis method is used to scale the design earthquake to different earthquake intensity levels;

[0008] S3. Using the constructed finite element analysis model of the gravity dam-foundation system and the ground motion under different scaling factors as inputs, conduct multiple sets of nonlinear dynamic response analyses to obtain the strong earthquake response results of the gravity dam-foundation system;

[0009] S4. Based on the strong earthquake response results of the gravity dam-foundation system, construct evaluation indicators to characterize the seismic performance of the gravity dam-foundation system;

[0010] S5. Construct line graphs showing the variation of different performance evaluation indicators with different scaling factors, and solve for the slope of each segment of the line graph. Determine the ultimate seismic resistance of the gravity dam based on the scaling factor corresponding to the maximum slope.

[0011] Furthermore, in step S2, scaling the design ground motion to different earthquake intensity levels is expressed as follows:

[0012]

[0013] In the formula, Indicates the first One scaling factor, Indicates the first One scaling factor, Indicates the first Each scaling step.

[0014] Furthermore, in step S3, the strong earthquake response results of the gravity dam-foundation system include dam damage factors. Residual sliding displacement of characteristic points on the sliding surface Displacement of characteristic points on the dam crest and displacement of characteristic points at the bottom of the dam .

[0015] Furthermore, in step S4, the evaluation index includes the maximum damage depth ratio, which characterizes the damage and failure of the dam body. The sliding area ratio index characterizes the sliding instability and failure of the weak sliding surface of the dam body. And the relative residual displacement index of the dam crest relative to the dam base, which comprehensively characterizes the two failure modes. Weighted average mixed index Harmonic average mixed index Nonlinear transformation hybrid index .

[0016] Furthermore, the maximum damage depth ratio index for:

[0017]

[0018] In the formula, This indicates the depth of macroscopic cracking in the dam body. This indicates the thickness at the corresponding elevation where damage and cracking have occurred in the dam body;

[0019] The sliding area ratio index for:

[0020]

[0021] In the formula, This represents the total area on the sliding surface where sliding occurs. Represents the total area of ​​the sliding surface;

[0022] The relative residual displacement index of the dam crest relative to the dam base for:

[0023]

[0024] In the formula, This indicates the displacement of a characteristic point on the dam crest. Indicates the displacement of a characteristic point at the bottom of the dam;

[0025] The weighted average mixed index for:

[0026]

[0027] The harmonic average mixing index for:

[0028]

[0029] The nonlinear transformation hybrid index for:

[0030] .

[0031] Furthermore, step S5 includes the following sub-steps:

[0032] S51. Construct line graphs showing how different performance evaluation indicators change with different scaling factors;

[0033] S52. In the line graph of each performance evaluation index, calculate the slope of each segment of the curve showing the change of the performance evaluation index with different scaling factors, expressed as:

[0034]

[0035] In the formula, These are the 1st, 2nd, and 3rd lines in the line chart. The slope of segment i These are the 1st, 2nd, and 3rd lines in the line chart. The x-coordinates of the (i+1)th point These are the 1st, 2nd, and 3rd lines in the line chart. The y-coordinates of the i+1 points;

[0036] S52. Determine the maximum slope value among the slopes of each segment in the line graph. ;

[0037] S53. Scaling factor corresponding to the maximum slope value in the line graph of different performance evaluation indicators. , , , , Determine the ultimate seismic resistance of the gravity dam-foundation system. for:

[0038]

[0039] In the formula, , , , , This represents the scaling factor value corresponding to the maximum slope value in the line graph of the 1st to jth performance evaluation indicators.

[0040] A quantitative evaluation system for the ultimate seismic resistance capacity of gravity dams includes:

[0041] Model building module: Used to build a finite element analysis model of the gravity dam-foundation system that simultaneously considers strength and stability failure of the gravity dam to be evaluated;

[0042] Design Seismic Scaling Module: Used to scale the design seismic intensity level to different seismic intensity levels for nonlinear dynamic response analysis of gravity dam-foundation systems using incremental dynamic analysis methods;

[0043] Nonlinear dynamic response analysis module: used to perform multiple sets of nonlinear dynamic response analyses on the finite element analysis model of the gravity dam-foundation system under different scaling factors, and obtain the strong earthquake response results of the gravity dam-foundation system;

[0044] Performance evaluation index construction module: used to construct performance evaluation indexes for the ultimate seismic resistance of gravity dams based on the strong earthquake response results of the gravity dam-foundation system;

[0045] Evaluation module: Used to quantitatively determine the ultimate seismic resistance of gravity dams based on line graphs showing the changes of different performance evaluation indicators with scaling factors.

[0046] Furthermore, the strong earthquake response results of the gravity dam-foundation system obtained by the nonlinear dynamic response analysis module include dam damage factors. Residual sliding displacement of characteristic points on the sliding surface Displacement of characteristic points on the dam crest and displacement of characteristic points at the bottom of the dam .

[0047] Furthermore, the performance evaluation indicators obtained by the performance evaluation index construction module include the maximum damage depth ratio index, which characterizes dam damage and failure. The sliding area ratio index characterizes the sliding instability and failure of the weak sliding surface of the dam body. And the relative residual displacement index of the dam crest relative to the dam base, which comprehensively characterizes the two failure modes. Weighted average mixed index Harmonic average mixed index Nonlinear transformation hybrid index .

[0048] Furthermore, the evaluation module includes:

[0049] Line chart building unit: Used to draw line charts of different performance evaluation indicators as a function of different scaling factors;

[0050] Slope calculation unit: used to calculate the slope of each segment in the line graph corresponding to each performance evaluation index, where the performance evaluation index changes with different scaling factors, and to determine the maximum slope value;

[0051] Ultimate Seismic Capacity Determination Unit: Used to determine the ultimate seismic capacity of the gravity dam-foundation system based on the scaling factor corresponding to the maximum slope value in the line graphs of different performance indicators.

[0052]

[0053] In the formula, , , , , This represents the scaling factor value corresponding to the maximum slope value in the line graph of the 1st to jth performance evaluation indicators.

[0054] The beneficial effects of this invention are as follows:

[0055] (1) This invention constructs a nonlinear finite element analysis model that is more in line with actual engineering and considers the dynamic coupling effect of dam damage development and bedrock sliding instability failure process. It breaks through the limitation of existing studies that mostly adopt the assumption of a single failure mode and effectively reflects the synergistic effect of multiple failure mechanisms in actual engineering.

[0056] (2) This invention constructs multiple evaluation indicators that can characterize a single failure mode and comprehensively consider the coupling of multiple failure modes, and evaluates the seismic performance of gravity dam-foundation system from multiple perspectives. It overcomes the isolated evaluation of different failure modes in traditional methods and lays the foundation for subsequent quantitative evaluation of the ultimate seismic resistance of dams.

[0057] (3) This invention provides a method for quantitatively evaluating the ultimate seismic resistance of dams, which overcomes the problem that traditional methods are difficult to accurately define the critical failure state of gravity dams under complex nonlinear coupling. It realizes the quantitative assessment of the safety margin of dams from normal working state to final failure, and provides a theoretical basis for seismic safety assessment and risk management. Attached Figure Description

[0058] Figure 1 The flowchart of the quantitative evaluation method for the ultimate seismic resistance capacity of gravity dams provided by the present invention is shown.

[0059] Figure 2 The dam body-foundation finite element mesh model provided for this invention.

[0060] Figure 3 The finite element mesh model of the dam body provided for this invention.

[0061] Figure 4 The contact seam surface distribution diagram provided for this invention.

[0062] Figure 5 This is a schematic diagram of the maximum damage depth ratio as a function of the scaling factor, provided by the present invention.

[0063] Figure 6 This is a schematic diagram of the variation curve of the residual sliding displacement of the feature point with the scaling factor provided by the present invention.

[0064] Figure 7 This is a schematic diagram of the curve showing the change of the sliding area ratio with the scaling factor provided by the present invention.

[0065] Figure 8 This is a schematic diagram of the curve showing the change of the relative residual displacement of the dam crest relative to the dam bottom with the scaling factor, which is provided by the present invention.

[0066] Figure 9 This is a schematic diagram of the weighted average hybrid index as a function of the scaling factor, which is provided by the present invention.

[0067] Figure 10 This is a schematic diagram of the curve of the harmonic average mixing index as a function of the scaling factor, provided by the present invention.

[0068] Figure 11 This is a schematic diagram of the curve of the nonlinear transformation hybrid index as a function of the scaling factor, provided by the present invention. Detailed Implementation

[0069] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0070] This invention provides a method for quantitatively evaluating the ultimate seismic resistance of gravity dams, such as... Figure 1 As shown, it includes the following steps:

[0071] S1. Based on the location of the weak structural layer of the gravity dam to be evaluated, construct a finite element analysis model of the gravity dam-foundation system that simultaneously considers strength and stability failure.

[0072] S2. The incremental dynamic analysis method is used to scale the design earthquake to different earthquake intensity levels;

[0073] S3. Using the constructed finite element analysis model of the gravity dam-foundation system and the ground motion under different scaling factors as inputs, conduct multiple sets of nonlinear dynamic response analyses to obtain the strong earthquake response results of the gravity dam-foundation system;

[0074] S4. Based on the strong earthquake response results of the gravity dam-foundation system, construct evaluation indicators to characterize the seismic performance of the gravity dam-foundation system;

[0075] S5. Construct line graphs showing the variation of different performance evaluation indicators with different scaling factors, and solve for the slope of each segment of the line graph. Determine the ultimate seismic resistance of the gravity dam based on the scaling factor corresponding to the maximum slope.

[0076] In step S2 of this embodiment of the invention, the design ground motion is scaled to different earthquake intensity levels as follows:

[0077]

[0078] In the formula, Indicates the first One scaling factor, Indicates the first One scaling factor, Indicates the first Each scaling step.

[0079] In step S3 of this embodiment of the invention, nonlinear dynamic response analysis is performed using parallel computing software for seismic analysis of ultra-large-scale concrete dams to obtain the strong seismic response results of the gravity dam-foundation system, including dam damage factors. Residual sliding displacement of characteristic points on the sliding surface Displacement of characteristic points on the dam crest and displacement of characteristic points at the bottom of the dam .

[0080] In step S4 of this embodiment of the invention, the evaluation index includes the maximum damage depth ratio index, which characterizes the damage and failure of the dam body. The sliding area ratio index characterizes the sliding instability and failure of the weak sliding surface of the dam body. And the relative residual displacement index of the dam crest relative to the dam base, which comprehensively characterizes the two failure modes. Weighted average mixed index Harmonic average mixed index Nonlinear transformation hybrid index .

[0081] Among them, the maximum damage depth ratio index for:

[0082]

[0083] In the formula, This indicates the depth of macroscopic cracking in the dam body. This indicates the thickness at the corresponding elevation of the dam body where damage and cracking have occurred. Macroscopic cracking refers to a damage factor greater than 0.8.

[0084] Sliding area ratio index for:

[0085]

[0086] In the formula, This represents the total area on the sliding surface where sliding occurs. Represents the total area of ​​the sliding surface;

[0087] Relative displacement index of dam crest relative to dam base for:

[0088]

[0089] In the formula, This indicates the displacement of a characteristic point on the dam crest. Indicates the displacement of a characteristic point at the bottom of the dam;

[0090] Weighted average mixed index for:

[0091]

[0092] Harmonic Mean Mixed Index for:

[0093]

[0094] Nonlinear transformation hybrid index for:

[0095]

[0096] In this embodiment, As a weighted average mixed indicator, the importance of the two indicators can be quantified and they are complementary; As a harmonized average mixed index, this index can balance the shortcomings of the two indices. When the two values ​​differ greatly, the result is biased towards the lower value. This is a nonlinear transformation hybrid index, suitable for two independent indices that require a cumulative effect, and the results tend to favor higher values.

[0097] Step S5 of this embodiment of the invention includes the following sub-steps:

[0098] S51. Construct line graphs showing how different performance evaluation indicators change with different scaling factors;

[0099] S52. In the line graph of each performance evaluation index, calculate the slope of each segment of the curve showing the change of the performance evaluation index with different scaling factors, expressed as:

[0100]

[0101] In the formula, These are the 1st, 2nd, and 3rd lines in the line chart. The slope of segment i These are the 1st, 2nd, and 3rd lines in the line chart. The x-coordinates of the (i+1)th point These are the 1st, 2nd, and 3rd lines in the line chart. The y-coordinates of the i+1 points;

[0102] S52. Determine the maximum slope value among the slopes of each segment in the line graph. ;

[0103] S53. Scaling factor corresponding to the maximum slope value in the line graph of different performance evaluation indicators. , , , , Determine the ultimate seismic resistance of the gravity dam-foundation system. for:

[0104]

[0105] In the formula, , , , , This represents the scaling factor value corresponding to the maximum slope value in the line graph of the 1st to jth performance evaluation indicators.

[0106] In this embodiment of the invention, a quantitative evaluation system for the ultimate seismic resistance capacity of gravity dams is also provided, implemented based on the above-mentioned quantitative evaluation method for the ultimate seismic resistance capacity of gravity dams, including:

[0107] Model building module: Used to build a finite element analysis model of the gravity dam-foundation system that simultaneously considers strength and stability failure of the gravity dam to be evaluated;

[0108] Design Seismic Scaling Module: Used to scale the design seismic intensity level to different seismic intensity levels for nonlinear dynamic response analysis of gravity dam-foundation systems using incremental dynamic analysis methods;

[0109] Nonlinear dynamic response analysis module: used to perform multiple sets of nonlinear dynamic response analyses on the finite element analysis model of the gravity dam-foundation system under different scaling factors, and obtain the strong earthquake response results of the gravity dam-foundation system;

[0110] Performance evaluation index construction module: used to construct performance evaluation indexes for the ultimate seismic resistance of gravity dams based on the strong earthquake response results of the gravity dam-foundation system;

[0111] Evaluation module: Used to quantitatively determine the ultimate seismic resistance of gravity dams based on line graphs showing the changes of different performance evaluation indicators with scaling factors.

[0112] In this embodiment of the invention, the nonlinear dynamic response analysis module performs nonlinear dynamic response analysis using parallel computing software for seismic analysis of ultra-large-scale concrete dams, obtaining the strong earthquake response results of the gravity dam-foundation system, including dam damage factors. Residual sliding displacement of characteristic points on the sliding surface Displacement of characteristic points on the dam crest and displacement of characteristic points at the bottom of the dam .

[0113] In this embodiment of the invention, the performance evaluation indicators obtained by the performance evaluation index construction module include the maximum damage depth ratio index, which characterizes dam damage and failure. The sliding area ratio index characterizes the sliding instability and failure of the weak sliding surface of the dam body. And the relative residual displacement index of the dam crest relative to the dam base, which comprehensively characterizes the two failure modes. Weighted average mixed index Harmonic average mixed index Nonlinear transformation hybrid index ;

[0114] Among them, the maximum damage depth ratio index for:

[0115]

[0116] In the formula, This indicates the depth of macroscopic cracking in the dam body. This indicates the thickness at the corresponding elevation of the dam body where damage and cracking have occurred. Macroscopic cracking refers to a damage factor greater than 0.8.

[0117] Sliding area ratio index for:

[0118]

[0119] In the formula, This represents the total area on the sliding surface where sliding occurs. Represents the total area of ​​the sliding surface;

[0120] Relative displacement index of dam crest relative to dam base for:

[0121]

[0122] In the formula, This indicates the displacement of a characteristic point on the dam crest. Indicates the displacement of a characteristic point at the bottom of the dam;

[0123] Weighted average mixed index for:

[0124]

[0125] Harmonic Mean Mixed Index for:

[0126]

[0127] Nonlinear transformation hybrid index for:

[0128]

[0129] In this embodiment, As a weighted average mixed indicator, the importance of the two indicators can be quantified and they are complementary; As a harmonized average mixed index, this index can balance the shortcomings of the two indices. When the two values ​​differ greatly, the result is biased towards the lower value. This is a nonlinear transformation hybrid index, suitable for two independent indices that require a cumulative effect, and the results tend to favor higher values.

[0130] The evaluation module of this invention includes:

[0131] Line chart building unit: Used to draw line charts of different performance evaluation indicators as a function of different scaling factors;

[0132] Slope calculation unit: used to calculate the slope of each segment in the line graph corresponding to each performance evaluation index, where the performance evaluation index changes with different scaling factors, and to determine the maximum slope value;

[0133] Ultimate Seismic Capacity Determination Unit: Used to determine the ultimate seismic capacity of the gravity dam-foundation system based on the scaling factor corresponding to the maximum slope value in the line graphs of different performance indicators.

[0134]

[0135] In the formula, , , , , This represents the scaling factor value corresponding to the maximum slope value in the line graph of the 1st to jth performance evaluation indicators.

[0136] In this embodiment of the invention, an engineering example of the above evaluation method is provided.

[0137] In this embodiment, taking a gravity dam as an example, a finite element analysis model of the gravity dam-foundation system is constructed based on the weak bedrock layer. This model is more realistic and comprehensively considers dam damage and sliding instability. Figure 2 , Figure 3 and Figure 4 As shown. The model has a total of 377,653 nodes and 349,864 elements. The dam body has a total of 71,906 nodes and 66,252 elements. The maximum dam height is 173.5m.

[0138] The material parameters used in the calculations are shown in the table below:

[0139] Table 1: Values ​​of physical and mechanical parameters of materials

[0140]

[0141] The loads applied in the calculation mainly include: the dam's self-weight, water load, silt load, uplift pressure, and seismic load.

[0142] Incremental dynamic analysis was employed, scaling the design earthquake by 1.0, 1.2, 1.4, 1.5, 1.6, 1.7, and 1.8 times. Multiple sets of nonlinear dynamic response analyses were conducted using the scaled seismic motions and the constructed finite element model of the gravity dam-foundation system as input. Based on the analysis results, line graphs were extracted and established to show the variations of maximum damage depth ratio, residual sliding displacement at characteristic points, sliding area ratio, relative residual displacement between the dam crest and dam base, weighted average mixed index, harmonic average mixed index, and nonlinear transformation mixed index as a function of the scaling factor. Figures 5-11 As shown.

[0143] according to Figures 5-11 As shown in Table 2, the line graphs of different performance evaluation indices as a function of scaling factors and the slope of each line segment reveal that the scaling factors corresponding to the maximum slope in the line graphs of maximum damage depth ratio, residual sliding displacement at characteristic points, sliding area ratio, relative residual displacement of dam crest to dam base, weighted average mixed index, harmonic average mixed index, and nonlinear transformation mixed index as a function of scaling factors are respectively... , , , , , , Therefore, the ultimate seismic resistance of the dam-foundation system can be determined. .

[0144] Table 2: Slope of each segment of the curve showing the change of different evaluation indicators with scaling factor

[0145]

[0146] Specific embodiments have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

[0147] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A method for quantitatively evaluating the ultimate seismic capacity of a gravity dam, characterized in that, The method comprises the following steps: S1, constructing a finite element analysis model of a gravity dam-foundation system considering both strength and stability failure according to the position of a weak layer of the gravity dam to be evaluated; S2, scaling the design earthquake to different seismic intensity levels by using an incremental dynamic analysis method; S3, carrying out a plurality of sets of nonlinear dynamic response analysis on the constructed finite element analysis model of the gravity dam-foundation system and the ground motion under different scaling coefficients to obtain strong earthquake response results of the gravity dam-foundation system; S4, constructing an evaluation index representing the seismic performance of the gravity dam-foundation system based on the strong earthquake response results of the gravity dam-foundation system; S5, constructing a broken line graph of different performance evaluation indexes varying with different scaling coefficients, and solving the slope of each broken line in the broken line graph, and determining the ultimate seismic capacity of the gravity dam according to the scaling coefficient corresponding to the maximum slope; The evaluation index in the step S4 includes a maximum damage depth ratio index representing damage and destruction of the dam body a sliding area ratio index representing sliding instability destruction of the weak sliding surface of the dam body and a relative residual displacement index of the dam top relative to the dam bottom comprehensively representing two destruction modes a weighted average mixed index a harmonic average mixed index a nonlinear transformation mixed index ; In the formula, represents the macroscopic cracking depth of the dam body damage, represents the thickness of the corresponding elevation of the dam body damage cracking, represents the total area of the sliding surface that occurs sliding, represents the total area of the sliding surface, represents the displacement of the characteristic point of the dam top, represents the displacement of the characteristic point of the dam bottom.

2. The method according to claim 1, wherein, In the step S2, scaling the design ground motion to different seismic intensity levels is represented as: wherein denotes the th scaling coefficient, denotes the th scaling coefficient, denotes the th scaling step.

3. The method according to claim 1, wherein, The strong earthquake response result of the gravity dam-foundation system in the step S3 includes a dam body damage factor , a residual sliding displacement of a sliding surface feature point , a dam top feature point displacement , and a dam bottom feature point displacement .

4. The method according to claim 1, wherein, The step S5 comprises the following sub-steps: S51, constructing a broken line graph of different performance evaluation indexes varying with different scaling coefficients; S52, solving the slope of each segment of the performance evaluation index curve varying with different scaling coefficients in the broken line graph of each performance evaluation index, which is represented as: In the formula, These are the 1st, 2nd, and 3rd lines in the line chart. The slope of segment i These are the 1st, 2nd, and 3rd lines in the line chart. The x-coordinates of the (i+1)th point These are the 1st, 2nd, and 3rd lines in the line chart. The y-coordinates of the i+1 points; S52, determine the maximum slope value in the slope of each segment in the broken line graph : S53, scaling factor corresponding to the maximum slope value in the different performance evaluation index broken line graph , , , , , determine the ultimate seismic capacity of the gravity dam-foundation system : In the formula, , , , , represents the value of the scaling factor corresponding to the maximum slope value in the first to jth performance evaluation index line graph.

5. A system for quantitatively evaluating the ultimate seismic capacity of a gravity dam, based on the method for quantitatively evaluating the ultimate seismic capacity of a gravity dam according to any one of claims 1 to 4, characterized in that, It comprises: A model construction module for constructing a finite element analysis model of a gravity dam-foundation system considering both strength and stability failure for a gravity dam to be evaluated; A design earthquake scaling module for scaling the design earthquake for carrying out nonlinear dynamic response analysis of the gravity dam-foundation system to different seismic intensity levels by using an incremental dynamic analysis method; A nonlinear dynamic response analysis module for carrying out a plurality of sets of nonlinear dynamic response analysis on the finite element analysis model of the gravity dam-foundation system under different scaling coefficients to obtain strong earthquake response results of the gravity dam-foundation system; A performance evaluation index construction module for constructing a performance evaluation index of the ultimate seismic capacity of the gravity dam according to the strong earthquake response results of the gravity dam-foundation system; An evaluation module for quantitatively determining the ultimate seismic capacity of the gravity dam according to the broken line graph of different performance evaluation indexes varying with scaling coefficients.

6. The system for quantitatively evaluating ultimate seismic capacity of gravity dam according to claim 5, characterized in that, The strong earthquake response results of the gravity dam-foundation system obtained by the nonlinear dynamic response analysis module include a dam body damage factor , a residual sliding displacement of a sliding surface feature point , a dam top feature point displacement , and a dam bottom feature point displacement .

7. The system according to claim 6, wherein, The performance evaluation index obtained by the performance evaluation index construction module includes a maximum damage depth-thickness ratio index representing damage and destruction of the dam body , a sliding area ratio index representing sliding instability and destruction of a weak sliding surface of the dam body , and a relative residual displacement index of the dam top relative to the dam bottom comprehensively representing two destruction modes , a weighted average mixed index , a harmonic average mixed index , and a nonlinear transformation mixed index .

8. The system for quantitatively evaluating ultimate seismic capacity of gravity dam according to claim 7, characterized in that, The evaluation module comprises: A broken line graph construction unit for drawing a broken line graph of different performance evaluation indexes varying with different scaling coefficients; A slope solving unit for solving the slope of each segment of the performance evaluation index curve varying with different scaling coefficients in the broken line graph corresponding to each performance evaluation index, and determining the maximum slope value; An ultimate seismic capacity determination unit for determining the ultimate seismic capacity of the gravity dam-foundation system according to the scaling coefficient corresponding to the maximum slope value in the broken line graph of different performance indexes, which is In the formula, , , , , represents the value of the scaling factor corresponding to the maximum slope value in the first to jth performance evaluation index line graph.

Images