A dam anti-seismic performance evaluation method and device and a storage medium

Abstract

The present application relates to dam safety monitoring technical field, especially point to a kind of dam seismic performance evaluation method, device, equipment and computer storage medium.The dam seismic performance evaluation method described in the present application, comprehensive proposed cross-scale analysis method, high-performance computing technology, whole-process generalized plastic coarse-grained soil constitutive model, inversion constitutive model parameter and seismic safety classification evaluation index system carry out seismic response analysis and safety evaluation, reveal the real dynamic characteristics and seismic performance of dam, quantify the influence of rheological effect on dynamic deformation, establish the dam seismic performance evaluation system based on monitoring data, to accurately describe the seismic performance of dam.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dam safety monitoring, in particular to a dam seismic performance evaluation method, device, equipment and computer storage medium. BACKGROUND

[0002] Water energy resources are important clean and renewable energy, which plays an important role in meeting energy demand, improving energy structure, promoting economic development, and reducing carbon dioxide emissions. China has planned, constructed and operated numerous high dam hydropower projects, which have promoted the sustainable and healthy development of regional economy and achieved significant social and economic benefits. However, in high-intensity seismic areas with complex geological structure and frequent seismic activity, the probability of strong earthquakes during the service period of the dam is relatively high, and there is a risk of strong earthquake damage or even collapse. Therefore, how to reveal the real dynamic characteristics and seismic performance of the dam is a problem we need to pay attention to.

[0003] Due to the dispersion of earth and rockfill dam engineering soil yard, the difference in soil origin and physical and mechanical properties, and the great uncertainty of the calculation parameters of earth and rockfill materials, the existing various quantitative calculation and analysis methods based on indoor test material parameters cannot accurately reflect the stress, deformation and permeability of earth and rockfill dams. static behavior, it is more difficult to describe the complex dynamic characteristics and seismic performance of earth and rockfill dams. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the problem that the existing technology cannot accurately describe the seismic performance of high earth and rockfill dams.

[0005] To solve the above technical problems, the present application provides a dam seismic performance evaluation method, comprising:

[0006] establishing a geometric entity model of the dam, and performing cross-scale fine grid discretization on the geometric entity model based on an octree algorithm to obtain a volume grid model;

[0007] analyzing the volume grid model using a nonlinear polyhedral proportional boundary finite element method to establish a finite element model;

[0008] based on the finite element model, establishing a generalized plastic coarse-grained soil constitutive model using a static-flow-dynamic unified whole-process, and performing an elastoplastic inversion analysis of the generalized plastic coarse-grained soil constitutive model considering the long-term deformation of the dam based on the measured data;

[0009] inputting seismic motion to the generalized plastic coarse-grained soil constitutive model with the inversion analysis result material parameters to calculate the dam crest settlement rate;

[0010] evaluating the seismic performance of the dam according to the dam crest settlement rate.

[0011] Preferably, after obtaining the volume grid model, it further comprises:

[0012] The nodes at the interfaces between the components are fused and shared.

[0013] Preferably, the body grid model is analyzed by using a nonlinear polyhedral proportional boundary finite element method, and the establishment of the finite element model comprises:

[0014] The body grid model is subjected to block cone domain integral;

[0015] The nonlinear stiffness matrix of the polyhedral element is calculated according to the strain displacement conversion matrix and the material elastoplasticity constitutive matrix at the domain integral point;

[0016] The nonlinear stiffness matrix of the polyhedral element is calculated according to the strain displacement conversion matrix and the material elastoplasticity constitutive matrix at the domain integral point;

[0017] The external force load vector is obtained according to the surface force load vector and the volume force load vector of the polyhedron;

[0018] The internal force load vector of the polyhedral element is calculated according to the strain displacement conversion matrix and the material nonlinear constitutive matrix at the domain integral point.

[0019] Preferably, the method for calculating the nonlinear stiffness matrix of the polyhedral element comprises:

[0020] For the cube element in the body grid model, a similar element acceleration algorithm is used to calculate the nonlinear stiffness matrix of the cube element:

[0021] The stiffness matrix of the unit cube element or the stiffness matrix at the integral point of the unit size element is calculated and stored in advance;

[0022] Based on the stiffness matrix of the unit cube element or the stiffness matrix at the integral point of the unit size element, the stiffness matrix of any cube element is obtained according to the corresponding proportional coefficient.

[0023] Preferably, the method for establishing the generalized plastic coarse-grained soil constitutive model comprises:

[0024] Since the material nonlinear degree and the load step length are inversely proportional, according to statistical data, the correlation between the current stress state nonlinear degree index and the strain integral step length is established;

[0025] According to the correlation relationship, the constitutive integration of the adaptive step length is carried out, and the generalized plastic coarse-grained soil constitutive model is established.

[0026] Preferably, the method for obtaining the seismic input is:

[0027] According to the characteristics of the seismic wave, the seismic stage is divided into grades;

[0028] Different monitoring time steps are adopted for different levels of earthquake stages, wherein the earthquake stage level and the monitoring time step are inversely proportional;

[0029] The seismic wave monitoring data is acquired according to the adaptive monitoring time step;

[0030] The seismic wave is intercepted according to the Arias intensity, and the seismic input is obtained.

[0031] Preferably, the dam anti-seismic performance evaluation according to the dam crest seismic subsidence rate comprises:

[0032] Since the dam crest seismic subsidence rate and the dam slope slip amount are positively correlated, the dam slope slip amount is calculated according to the dam crest seismic subsidence rate;

[0033] If the dam slope slip amount is not higher than the non-failure dam index, the earthquake damage degree is judged according to the dam crest seismic subsidence rate and the pre-established seismic safety classification evaluation index.

[0034] The application also provides a dam anti-seismic performance evaluation device, comprising:

[0035] A grid model establishment module is configured to establish a geometric entity model of the dam and perform cross-scale fine grid discretization on the geometric entity model based on an octree algorithm to obtain a volume grid model;

[0036] A finite element module establishment module is configured to analyze the volume grid model using a nonlinear polyhedral proportional boundary finite element method to establish a finite element model;

[0037] An inversion analysis module is configured to establish a generalized plastic coarse-grained soil constitutive model using a static-flow-dynamic unified whole-process based on the finite element model, and perform an elastoplastic inversion analysis of the generalized plastic coarse-grained soil constitutive model considering long-term deformation of the dam based on measured data;

[0038] An anti-seismic index calculation module is configured to perform seismic input on the generalized plastic coarse-grained soil constitutive model using the inversion analysis result material parameters to calculate a dam crest seismic subsidence rate;

[0039] An anti-seismic performance evaluation module is configured to evaluate the dam anti-seismic performance according to the dam crest seismic subsidence rate.

[0040] The application also provides a dam anti-seismic performance evaluation device, comprising:

[0041] A memory is configured to store a computer program;

[0042] A processor is configured to execute the computer program to realize the steps of the above dam anti-seismic performance evaluation method.

[0043] The application further provides a computer readable storage medium, wherein a computer program is stored on the computer readable storage medium, and the computer program is executed by a processor to implement steps of the dam seismic performance evaluation method.

[0044] Compared with the prior art, the technical scheme has the following advantages:

[0045] The dam seismic performance evaluation method provided by the application comprehensively uses a cross-scale analysis method, a high-performance computing technology, a generalized plastic coarse-grained soil constitutive model, inverted constitutive model parameters and a seismic safety grading evaluation index system to perform seismic response analysis and safety evaluation, reveals real dynamic characteristics and seismic performance of the dam, quantifies influences of rheological effects on dynamic deformation, and establishes a dam seismic performance evaluation system based on monitoring data, so as to accurately describe the seismic performance of the dam. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to make the content of the application more easily understood, the application will be further described in detail below according to specific embodiments of the application and in combination with the drawings, in which:

[0047] Figure 1 is an implementation flowchart of the dam seismic performance evaluation method provided by the application;

[0048] Figure 2 is an integral point distribution schematic diagram of the domain integral scheme 1;

[0049] Figure 3 is a triangular domain integral point distribution comparison schematic diagram of the domain integral scheme 1 and 2;

[0050] Figure 4 is an integral point distribution schematic diagram of each tetrahedron in the domain integral scheme 3;

[0051] Figure 5 is a similarity relationship schematic diagram of a square element stiffness matrix in an elastic problem;

[0052] Figure 6 is a similarity relationship schematic diagram of a square element stiffness matrix in a Lee-Fenves plastic damage model;

[0053] Figure 7 is a similarity relationship schematic diagram of a square element stiffness matrix in a soil generalized plastic model;

[0054] Figure 8 is a precision comparison schematic diagram before and after optimization of a constitutive integral step;

[0055] Figure 9 is a time step optimization schematic diagram;

[0056] Figure 10 is an accuracy comparison schematic diagram before and after time step optimization;

[0057] Figure 11 is a seismic motion input schematic diagram;

[0058] Figure 12 is a schematic diagram of the relationship between the dam crest subsidence rate and the peak acceleration;

[0059] Figure 13 is a post-earthquake deformation schematic diagram. DETAILED DESCRIPTION

[0060] The core of the present application is to provide a dam seismic performance evaluation method, device, equipment and computer storage medium, which effectively improves the accuracy of dam seismic performance description.

[0061] In order to enable personnel in the art to better understand the present application, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0062] Please refer to Figure 1, Figure 1 is an implementation flowchart of a dam seismic performance evaluation method provided by the present application; the specific operation steps are as follows:

[0063] S101: Establish a geometric entity model of the dam, and perform cross-scale fine grid discretization on the geometric entity model based on an octree algorithm to obtain a volume grid model;

[0064] S102: Analyze the volume grid model using a nonlinear polyhedral proportional boundary finite element method to establish a finite element model;

[0065] S103: Based on the finite element model, establish a generalized plastic coarse-grained soil constitutive model using a static-flow-dynamic unified whole-process, and perform an elastoplastic inversion analysis of the generalized plastic coarse-grained soil constitutive model considering long-term deformation of the dam based on measured data;

[0066] S104: Perform seismic motion input on the generalized plastic coarse-grained soil constitutive model with inversion analysis result material parameters to calculate the dam crest subsidence rate;

[0067] S105: Evaluate the dam seismic performance according to the dam crest subsidence rate.

[0068] Based on the above embodiments, the step S101 is described in detail in the present embodiment:

[0069] According to the numerical calculation requirement, the discrete grid size of each component can be set, and the eight-part tree Octree cross-scale fine grid is directly dispersed to the created dam BIM geometric entity model. Subsequently, the coded data of the dispersed model can be converted into finite element data available for CAE software by self-programming.

[0070] 1. Based on the IFC standard, the BIM geometric entity of Dashixia is imported into the Octree grid generation software through an intermediate file.

[0071] 2. For some grid generation software, error checking function needs to be run in advance to recheck geometric errors (such as perforated surface, free edge, non-manifold node, non-manifold edge, etc.). If there are local detail errors, the model needs to be repaired through the automatic repair function of the software or manual edge structure operation, otherwise subsequent dispersion work cannot be carried out.

[0072] 3. According to the numerical calculation requirement, the discrete grid size parameters of each partition component can be set according to the calculation accuracy, and some methods can be used for local size control. Different grid size parameters can be combined to form multiple dispersion schemes, and the optimal scheme is calculated according to the total quality and quantity of the dispersed unit.

[0073] 4. Run the Octree dispersion program to get the volume grid model.

[0074] 5. Use the node fusion (merge) function to make the similar nodes at the interface between each component share, which is convenient for subsequent numerical calculation.

[0075] Based on the above embodiment, step S102 is described in detail:

[0076] Said analyzing the volume grid model by using the nonlinear polyhedral proportional boundary finite element method includes:

[0077] ·Integrating the volume grid model in the block cone domain:

[0078] The present application provides three different domain integral schemes, which are defined as scheme 1, scheme 2 and scheme 3 for simplifying naming and expression.

[0079] 1) Domain integral scheme 1

[0080] Figure 2 The integral point selection is shown in the schematic diagram, wherein is the polygon average value interpolation function, N FEM is the linear interpolation function of the triangular element, and the implementation process is introduced as follows:

[0081] Firstly, each ring boundary surface element is converted into a corresponding standard isoparametric regular polygon element. Then, the center of the circle and the corner point of the regular polygon are connected to divide each polygon into multiple triangles. Three integral points are selected in each triangular domain, whose local coordinates (r, s) are (1 / 6, 1 / 6), (2 / 3, 1 / 6), and (1 / 6, 2 / 3) respectively, and the corresponding weights are 1 / 3. These are referred to as boundary area integral points.

[0082] As shown in Figure 2 , the dimensionless radial coordinate ξ has a value range of [0, 1], and takes a value of 0 at the proportional center and a value of 1 at the boundary. According to the quadrature rule in one-dimensional problems, two integral points can be selected at positions . For three-dimensional problems, the two points in one-dimensional problems correspond to two planes in three-dimensional problems, as described in detail in Figure 2 . Then, integral points are inserted on the two selected ξ planes, and the positions of the inserted points are completely consistent with the boundary integral points, except that the weights will change to 1 / 6. These inserted integral points are referred to as domain integral points.

[0083] 2) Domain integral scheme 2

[0084] The idea of scheme 2 is completely similar to that of scheme 1, and the boundary integral points of the two schemes are completely consistent. The difference is the number of domain integral points selected. In scheme 2, only one integral point is allocated in each triangular domain within the two planes where the integral points are inserted, i.e., the integral accuracy is first-order accuracy, and the coordinates are (1 / 3, 1 / 3), as shown in Figure 3 .

[0085] 3) Domain integral scheme 3

[0086] In a polyhedral element, connecting the proportional center and the nodes of each ring boundary surface can obtain different conical elements. For any conical element, by connecting the proportional center (O) O and the center point of the ring boundary surface (O) O ׳ , and then connecting the center point of the ring boundary surface and the boundary surface nodes, the conical element can be divided into multiple tetrahedral elements. As shown in Figure 4 , in each tetrahedral element, according to the Hammer integral rule, four integral points (Wang Xu-cheng, 2002) are introduced, whose coordinates are represented as a (α, β, β, β), b(β, α, β, β), c (β, β, α, β), d (β, β, β, α), where α and β take values of 0.5854102 and 0.1381966 respectively, and the corresponding weights are 1 / 24.

[0087] Among them, scheme 3 is the optimal selected scheme, which has the highest calculation accuracy and the highest error reduction speed.

[0088] • The nonlinear stiffness matrix of the polyhedral element is calculated according to the strain-displacement transformation matrix and the material elastoplastic constitutive matrix at the integration points within the domain:

[0089] The nonlinear stiffness matrix calculation formula of the polyhedral element can be solved by the strain-displacement matrix and the constitutive matrix, see formula (1):

[0090] (1)

[0091] By selecting the integration points within the domain, the definite integral is calculated, and formula (1) can be expanded as formula (2):

[0092] (2)

[0093] Wherein m is the number of boundary surfaces of the polyhedral element, p k is the total number of integration points within the domain in the kth boundary surface, B i ( ξ , ξ 1, ξ 2) represents the strain-displacement transformation matrix at the ith integration point; is the material elastoplastic constitutive matrix value at the ith integration point; V i is the volume represented by the ith integration point V e .

[0094] • The nonlinear stiffness matrix of the polyhedral element is calculated according to the strain-displacement transformation matrix and the material elastoplastic constitutive matrix at the integration points within the domain:

[0095] • The external force load vector is obtained according to the surface force load vector and the volume force load vector of the polyhedral element:

[0096] The external force load vector R ext is expressed as formula (4-1-3).

[0097] (3)

[0098] Wherein the first term on the right side of the equation is the surface force load vector, on the boundary surface ( ξ = 1), the formula can be expanded as formula (4):

[0099] (4)

[0100] The second term on the right side of the equation is the volume force load vector, which can be expanded as formula (5) according to the numerical integration calculation:

[0101] (5)

[0102] The internal force load vector of the polyhedral element is calculated according to the strain-displacement conversion matrix and the material nonlinear constitutive matrix at the integration points in the domain:

[0103] The internal force load vector calculation formula can be written as (6).

[0104] (6)

[0105] According to the element strain calculation formula, the polyhedral element strain is solved ε ( ξ , ξ 1, ξ 2), see formula (7), using Hooke's law, the element stress is solved σ i ( ξ , ξ 1, ξ 2), see formula (4-1-8), wherein is the material nonlinear constitutive matrix.

[0106] (7)

[0107] (8)

[0108] Using the block cone domain integration scheme, (7) and (8) are substituted into formula (6), and the numerical integration calculation formula of the internal force vector of the polyhedral element can be obtained, see (9):

[0109] (9)

[0110] Wherein m is the number of boundary surfaces of the polyhedral element, p k is the total number of integration points in the kth boundary surface, B ki ( ξ , ξ 1, ξ 2) represents the strain-displacement conversion matrix at the ith integration point in the kth boundary surface, which is calculated by formula (6); is the material nonlinear constitutive matrix value at the ith integration point; V ki is the volume represented by the ith integration point in the kth boundary surface V e .

[0111] Based on the above embodiment, the calculation method of the nonlinear stiffness matrix of the polyhedral element comprises:

[0112] • For cube elements in the volume mesh model, a similarity element acceleration algorithm is used to calculate the nonlinear stiffness matrix of the cube elements:

[0113] • Pre-calculate and store the stiffness matrix of a unit cube element or the stiffness matrix at the integration point of a unit-size element;

[0114] • Based on the stiffness matrix of the unit cube element or the stiffness matrix at the integration point of the unit size element, the stiffness matrix of any cube element is obtained according to the corresponding scaling factor.

[0115] For a spatial eight-node isoparametric element in the finite element method, the stiffness matrix of each element is calculated as follows: The calculation formula expands to Solving for the element stiffness matrix requires 32,832 additions and 35,136 multiplications. Similarly, the mass matrix, permeability matrix, compression matrix, and coupling matrix in the analysis of saturated porous media all require numerous arithmetic operations. When performing large-scale calculations involving millions or even tens of millions of degrees of freedom, the computational load on elements is extremely high.

[0116] An octet tree is used for mesh discretization, and the large proportion of cubic elements is one of the significant characteristics of the mesh. In representative discretized models, approximately 50% to 65% of the elements are cubic. For cubic elements, their shapes are completely identical, differing only by a size factor; therefore, these elements are geometrically similar. Given the element matrix of a unit-size cube, it is easy to describe the element matrix of other cubes of the same material. The following examples, using elastic models, concrete plastic damage models, and generalized plasticity models, illustrate this in detail:

[0117] For elastic problems, when calculating element stiffness, the strain-displacement matrix of a cube element with side length l and a unit-size element is considered. B Material constitutive matrix D And the unit volume V exists Figure 5 The relationship shown can be easily obtained by substituting it into the stiffness matrix calculation formula. K l and K The proportional relationship is 1, where the proportionality coefficient is... S c Let the element side length l and the material elastic modulus be... E l The product of these components. Therefore, the stiffness matrix of a unit cube element can be pre-calculated and stored. K 1, then through the scaling factor S c This allows us to obtain the stiffness matrix of cube elements of any size. K1. According to statistics, the element stiffness matrix calculation adopts element similarity acceleration, without addition operation, and can reduce 98.4% of multiplication operation amount, greatly improving the calculation efficiency of element matrix. Similarly, mass matrix, damping matrix, etc. can also be solved through this idea.

[0118] From the elastic similar element algorithm, it can be seen that the similarity coefficient S c It is mainly related to the size of the element and the elastic modulus of the material. In the Lee-Fenves plastic damage model and the generalized plastic model of soil, when the element starts to damage or the soil enters the plastic state, the value of the material modulus at each integration point is different, so the overall element does not have similarity.

[0119] But at the integration point j with the same local coordinates, the material modulus has similarity, so the stiffness matrix at this point has similarity, so the stiffness matrix at the integration point of the unit size element [K l ] j Then the proportional coefficient at each integration point is used S cj Calculate the stiffness matrix of any element (K Figure 6 And Figure 7 ). Through statistics, after using similar elements to accelerate the calculation of each element stiffness matrix, the addition operation can be reduced by 85.9% and the multiplication operation can be reduced by 88.5%, which is quite remarkable.

[0120] Based on the above embodiments, step S103 is described in detail:

[0121] The analysis and analysis of the prototype monitoring data are very important for understanding the true deformation characteristics of the earth-rock dam and carrying out the inversion analysis work. For the inversion of the rockfill parameters, it is meaningful to carry out the inversion analysis work only on the premise of ensuring the rationality and reliability of the monitoring data. A large amount of measured data has been obtained during the filling period, impounding period and normal operation period of Nuozhadu super high core wall dam, which is very valuable for scientific research of earth-rock dam. Therefore, before carrying out the inversion analysis, the measured data is analyzed and analyzed, on the one hand, the true deformation characteristics of the super high core wall dam can be well understood, on the other hand, reliable basis is provided for the later inversion analysis work, so as to select reasonable and reliable inversion target measuring point and target value.

[0122] The improved generalized plastic model of Dagong has greater advantages than Duncan-Zhang E-B model in simulating the static deformation of dam. It not only agrees well with the measured value in vertical settlement, but also agrees well with the measured value in river direction displacement. At the same time, the improved generalized plastic model of Dagong can realize static, dynamic and post-seismic deformation analysis with a set of parameters, which is convenient for the research of dam seismic performance.

[0123] Through the analysis of the measured data, it can be seen that the rheological deformation of the rockfill material is large, and should be considered in numerical calculation. In the past, the inversion analysis or numerical simulation without considering rheology actually defaults to include rheological deformation in instantaneous deformation, which weakens the parameters of the instantaneous constitutive model, and the rheology of rockfill material refers to the change of deformation with time after loading (filling), that is, the crushing and rearrangement of stones over time, which is essentially different from instantaneous deformation, and the instantaneous deformation and rheological deformation should be considered comprehensively.

[0124] Therefore, based on the existing static and dynamic unified generalized plasticity model, a static and dynamic unified elastoplastic constitutive model of coarse-grained soil considering rheological effect is proposed. By using the proposed model, elastoplastic inversion analysis considering long-term deformation of the dam is carried out. The results show that, whether in the filling stage or in the normal operation stage of the dam, the calculated values of vertical settlement and river direction displacement of most measuring points in the downstream dam body are in good agreement with the measured values, proving the reliability of the inversion results and the rationality of the constitutive model parameters, and the inversion analysis results considering long-term deformation of the dam can accurately predict the deformation of the dam in the normal operation stage, and also lay a foundation for accurate prediction of dynamic response of the dam.

[0125] Based on the above embodiment, the method for establishing the generalized plastic coarse-grained soil constitutive model comprises:

[0126] · According to statistical data, an association relationship between the current stress state nonlinear degree index and the strain integral step is established, since the material nonlinear degree and the load step are inversely proportional;

[0127] · The constitutive integral of adaptive step is carried out according to the association relationship, and the generalized plastic coarse-grained soil constitutive model is established.

[0128] The nonlinear finite element analysis accuracy and convergence speed are closely related to the load step and the material nonlinear degree, and the stronger the nonlinear degree, the smaller the required load step. For high earth-rock dam engineering, the nonlinear degree of the whole model is not the same in space and time during the whole earthquake process. The present application establishes an association relationship between the current stress state nonlinear degree index and the strain integral step through statistical data, and proposes a constitutive integral method of adaptive step, which improves the calculation efficiency of constitutive integral by 4.2 times under the condition of ensuring the same accuracy (see Figure 8 ).

[0129] Based on the above embodiment, step S104 is described in detail in this embodiment.

[0130] · The dam slope slip amount is calculated according to the dam top seismic subsidence rate, since the dam top seismic subsidence rate and the dam slope slip amount are positively correlated;

[0131] If the dam slope slip amount is not higher than the non-failure dam index, the earthquake damage degree is judged according to the dam top subsidence rate and the pre-established earthquake safety classification evaluation index.

[0132] The basic understanding of dam anti-seismic fortification in China is that the dam does not break under medium earthquake, can be repaired under strong earthquake, and does not cross under extreme earthquake, that is, under the condition of extreme earthquake, the dam can be damaged to a certain extent or even seriously damaged, but the dam should be able to maintain its water storage capacity and not collapse. The safety problem of earth-rock dam under strong earthquake, namely the ultimate anti-seismic capacity of earth-rock dam, is concerned, and the main analysis contents include how much earthquake the earth-rock dam can withstand, the safety margin of the dam under strong earthquake, what damage the dam will have under strong earthquake and the damage mode, etc. The ultimate anti-seismic capacity of high earth-rock dam is relatively complex, and many scholars at home and abroad have carried out a lot of research on it, but there is no uniform specification or standard to explain the evaluation criteria of the ultimate anti-seismic capacity of earth-rock dam at present.

[0133] Reservoir water overtopping is the primary problem for judging the dam break of earth-rock dam under earthquake. The dam top subsidence will be obvious under strong earthquake, and if the dam top elevation is lower than the reservoir water level caused by earthquake, the risk of overtopping dam break will be caused. In order to prevent reservoir water overtopping, the allowed earthquake dam top settlement should be less than the water level superhigh on the upstream side, so the dam top subsidence is the key index for judging the dam break of high earth-rock dam.

[0134] The present application carries out the research on the ultimate anti-seismic capacity evaluation quantitative index of high earth-rock dam under different dam height, dam top width, dam slope gradient, peak intensity of ground motion and ground motion characteristics. For high core wall dam, through the summary of the design of high core wall rockfill dam built, under construction and to be built in China, the calculation conditions are set as dam height: 200m, 250m and 300m, dam top width is 16m, upstream and downstream dam slope is 1:1.9 and 1:1.8 respectively, the finite element model of high core wall dam typical working condition, wherein the dam slope is selected as the most unfavorable design condition of high dam, the input ground motion of actual engineering such as Lawa, Dashiqia, Houziyan, etc. is used, the dynamic response calculation uses the elastic-plastic dynamic analysis method, the constitutive model of rockfill material uses the generalized plastic model improved by Daigong, the dam slope slip amount is calculated by the finite element dynamic stability and slip deformation analysis method, so as to explore the correlation between the subsidence rate and the slip amount. In the dynamic calculation, the dam top subsidence rate refers to the ratio of the vertical settlement of the dam top midpoint to the dam height, and the slip amount is calculated by the sliding surface of the sliding arc position through the transition and filter interface. Through the calculation of different ground motion peaks of the set working condition, the relationship between the core wall dam top subsidence rate and the slip amount is sorted out, and it can be found that the dam top subsidence rate and the dam slope slip amount show obvious positive correlation, in addition, since the dam slope slip is only local shallow sliding, it can be considered that it has been reflected in the dam top subsidence, and the dam top subsidence is the true embodiment of the dam deformation.

[0135] In the design of dam, there is a certain height difference between the normal storage level of the dam and the elevation of the dam crest (referred to as height difference in the project, and the ratio of the height difference to the dam height is referred to as "height difference rate"). The project summarizes 35 earth-rockfill dam projects at home and abroad, with dam height ranging from 126m to 315m. According to the statistical results, the height difference rate of the built earth-rockfill dams at home and abroad is greater than 2%, that is, when the seismic subsidence rate of the dam is not greater than 2% during normal storage, the problem of reservoir water overflowing the dam crest will not occur.

[0136] According to the statistical data of actual seismic damage of earth-rockfill dams in Swaisgood (2003) and the seismic damage of Zipingpu Dam, it can be seen from the statistical results that the seismic subsidence rate of the earth-rockfill dam increases gradually with the increase of the peak acceleration, but there is no sudden change trend between the seismic subsidence rate and the peak acceleration. According to the existing seismic damage results, when the seismic subsidence rate of the core wall rockfill dam is less than 1.1%, there is no problem of the dam being unable to repair and meet the subsequent operation function after the earthquake; in addition, multiple earth dams and hydraulic filling dams have a seismic subsidence rate greater than 1.5% without catastrophic damage (the construction and control standards of earth-rockfill dams are better than those of earth dams and hydraulic filling dams, so they should be safer under the same seismic subsidence rate conditions).

[0137] Considering that the construction quality and control standards of the current roller compacted earth-rockfill dam are far superior to those of the earth dam and the hydraulic filling dam, and combining with the existing roller compacted earth-rockfill dam seismic damage case, while making a certain conservative treatment, it is suggested that the seismic subsidence rate of the high core wall dam without dam failure index is 1.3%.

[0138] The calculation results show that there is a positive correlation between the dam crest seismic subsidence rate and the dam slope slip amount. For the core wall dam, when the seismic subsidence rate is 1.1%, 1.2% and 1.3% respectively, the boundary maximum value of the dam slope slip amount is about 1.0m, 1.2m and 1.4m respectively. According to this, it is suggested that the dam slope slip amount of the high face slab dam without dam failure index is 1.2m, and the dam slope slip amount of the high core wall dam without dam failure index is 1.4m.

[0139] Since the dam crest subsidence is the concentrated embodiment of the overall deformation of the dam, the local shallow slip of the dam slope has been reflected in the dam crest subsidence, and the dam crest subsidence deformation is the core problem of the seismic safety of the modern roller compacted earth-rockfill dam. Therefore, on the basis of the determined dam crest subsidence without dam failure index, the dam crest subsidence is divided into five levels, as shown in Table 1, and the seismic safety classification evaluation index of the core wall dam is established.

[0140] Table 1 Seismic safety classification evaluation index

[0141]

[0142] Based on the above embodiments, the method for obtaining the seismic input is:

[0143] · According to the characteristics of the seismic wave, the seismic stage is divided into levels;

[0144] adopt different monitoring time steps for different levels of earthquake stages, wherein the earthquake stage level and the monitoring time step are inversely proportional;

[0145] obtaining the seismic wave monitoring data according to the adaptive monitoring time step;

[0146] The time step of the nonlinear finite element is related to the load size and the nonlinear degree, wherein the larger the load and the stronger the nonlinear degree, the smaller the required time step. In view of this, according to the characteristics of the seismic wave during the calculation of the earth-rock dam, a larger time step can be adopted in the small earthquake stage to improve the calculation efficiency; and a smaller time step can be adopted in the strong earthquake stage to improve the calculation accuracy, as shown in Figure 9 The calculation accuracy before and after optimization is compared in Figure 10 In the case of unchanged accuracy, the calculation efficiency is improved by 12%.

[0147] performing seismic wave interception on the seismic wave monitoring data according to the Arias intensity to obtain the seismic input.

[0148] The acceleration time history of the seismic event generated by the strong earthquake monitoring system of the Nuozhadu Project is as long as 180s. However, the main energy of the earthquake is concentrated in the middle part of dozens of seconds, and if the monitoring data is directly used as the seismic input, the calculation of the 180s earthquake process is required, which will greatly increase the calculation time and is difficult to meet the requirements of the earthquake rapid analysis and evaluation. Therefore, the influence of the seismic wave truncation length on the calculation result is studied.

[0149] In the present application, 71 actual seismic waves with shear wave velocity vs30 of 600-2000m / s and magnitude of 4-8.5 are selected to carry out elastic-plastic dynamic response analysis of the core wall dam with a height of 300m, the Arias intensity is calculated, and the dam top settlement difference before and after the seismic wave truncation is quantified as an evaluation index defined by the duration.

[0150] Under different seismic intensities, the influence of the seismic wave interception length on the calculation result is shown in Table 2. When the seismic wave with 90% Arias intensity is intercepted, the average error is about 10%, and the average calculation time is saved by about 60%; when the seismic wave with 95% Arias intensity is intercepted, the average error is about 5%, and the average calculation time is saved by about 55%; and when the seismic wave with 99% Arias intensity is intercepted, the average error is about 1%, and the average calculation time is saved by about 35%.

[0151] Table 2 Influence of seismic wave interception range on calculation result

[0152]

[0153] The application introduces an octant algorithm in the field of computer graphics, and realizes fast cross-scale refined grid discretization by continuously recursively octantizing a discrete domain; a polygon average value interpolation function is used to interpolate the circumferential boundary surface of a polyhedron, and SBFEM of a complex polyhedron is derived and numerically realized, the solving problem of the polyhedron element caused by the octant modeling which is difficult to be solved by the conventional finite element method is solved, and finally a high earth-rock dam cross-scale modeling and analysis method coupled with proportional boundary elements and finite elements is established.

[0154] The application adopts a similar unit acceleration algorithm, and can greatly save the calculation amount of the unit stiffness matrix for elastic problems and nonlinear problems of rock-soil materials. Combined with the developed adaptive constitutive integration, variable solving time step and seismic motion truncation algorithm, fast analysis of high earth-rock dams is realized, and technical support is provided for rapid risk assessment and early warning of strong earthquakes.

[0155] Based on the above embodiment, the material parameters of the embodiment are obtained from the inversion analysis results, the damping ratios of all materials are fixed, the bedrock is 0.003, and the core wall material and the rockfill material are 0.05. Seismic motion is given in the vertical direction, the river direction and the dam axial direction, wherein the peak value of the vertical seismic motion is 2 / 3 of the horizontal direction, and the seismic acceleration time history (taking the design earthquake as an example) is shown in Figure 11 The wave input method based on artificial boundary and equivalent load is used for seismic motion input, which considers the interaction between the dam and the bedrock and the seismic radiation damping effect, and the theoretical calculation result should be more reasonable. Based on the above settings, the seismic response prediction of the super-high core wall dam under the design earthquake (PGA=0.283g) and the checking earthquake (PGA=0.345g) is carried out (the peak value of the seismic motion of the design earthquake and the checking earthquake refers to the horizontal peak value).

[0156] The dam seismic safety grading evaluation index system established by the application is used to evaluate the safety of the super-high core wall dam under the design earthquake and the checking earthquake, as shown in Table 3, under the action of the design earthquake and the checking earthquake, the seismic subsidence of the dam top is 0.54% and 0.63% respectively, which is slight damage.

[0157] In addition, without considering the rheological effect, the modulus of the dam is underestimated, and the post-seismic deformation of the dam is overestimated, wherein the deformation in the river direction is 15-40% larger, and the vertical deformation is 10% larger.

[0158] Table 3 Dam dynamic response and safety evaluation

[0159]

[0160] The application combines the high earth-rock dam non-failure quantitative index system introduced above, and analyzes the ultimate seismic capacity based on the elastoplastic inversion analysis results of whether considering the rheology in the inversion process. On the basis of analyzing the dam suffering from the design earthquake and the checking earthquake, gradually increasing the peak acceleration of ground motion, and developing the ground motion response prediction of the horizontal peak acceleration of ground motion being 0.6g, 0.65g, 0.7g, 0.75g and 0.8g respectively, it can be found from the calculation results that the maximum vertical settlement occurs at the dam top near the typical section, the relationship between the dam top earthquake subsidence rate and the peak acceleration is shown in Figure 12 , and the post-earthquake deformation mode is shown in Figure 13 . When the inversion parameters considering the rheological effect are used, the ultimate seismic capacity of the dam is about 0.75g; when the inversion parameters not considering the rheological effect are used, the modulus of the dam body is underestimated, and the ultimate seismic capacity of the dam is about 0.05g.

[0161] The dam seismic performance evaluation device provided by the embodiment of the application also provides a dam seismic performance evaluation device; the specific device can include:

[0162] A grid model establishing module is configured to establish a geometric entity model of the dam, and perform cross-scale fine grid discretization on the geometric entity model based on an octree algorithm to obtain a volume grid model;

[0163] A finite element module establishing module is configured to analyze the volume grid model by using a nonlinear polyhedral proportional boundary finite element method to establish a finite element model;

[0164] An inversion analysis module is configured to establish a generalized plastic coarse-grained soil constitutive model using a static-rheological-dynamic unified whole process based on the finite element model, and perform elastoplastic inversion analysis on the generalized plastic coarse-grained soil constitutive model considering the long-term deformation of the dam based on the measured data;

[0165] An anti-seismic index calculating module is configured to input the generalized plastic coarse-grained soil constitutive model using the inversion analysis result material parameters into the seismic motion, and calculate the dam top earthquake subsidence rate;

[0166] An anti-seismic performance evaluation module is configured to evaluate the dam seismic performance according to the dam top earthquake subsidence rate.

[0167] The dam seismic performance evaluation device of the embodiment is used to realize the dam seismic performance evaluation method described above, so the specific embodiments in the dam seismic performance evaluation device can be seen from the embodiment part of the dam seismic performance evaluation method, for example, the grid model establishing module, the finite element module establishing module, the inversion analysis module, the anti-seismic index calculating module and the anti-seismic performance evaluation module are respectively used to realize steps S101, S102, S103, S104 and S105 in the dam seismic performance evaluation method, so the specific embodiments can refer to the description of the corresponding respective embodiment part, and will not be repeated here.

[0168] The embodiment of the present application further provides a dam anti-seismic performance evaluation device, comprising: a memory for storing a computer program; and a processor for realizing the steps of the dam anti-seismic performance evaluation method when the computer program is executed.

[0169] The embodiment of the present application further provides a computer readable storage medium, wherein the computer readable storage medium stores a computer program, and the computer program realizes the steps of the dam anti-seismic performance evaluation method when the computer program is executed by a processor.

[0170] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. In addition, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage media, etc.) containing computer-usable program code.

[0171] The present application is described with reference to the flowcharts and / or block diagrams of the method, device (system), and computer program product according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be realized by computer program instructions. The computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device implemented in the flowcharts and / or block diagrams. Figure 1 The function specified in one or more flows and / or blocks Figure 1 The device that realizes the function specified in one or more flows or blocks.

[0172] The computer program instructions can also be stored in a computer readable memory capable of guiding the computer or other programmable data processing devices to work in a specific manner, so that the instructions stored in the computer readable memory produce a manufactured product including instruction devices, which realize the functions specified in the flowcharts and / or block diagrams. Figure 1 The function specified in one or more flows and / or blocks Figure 1 The device that realizes the function specified in one or more flows or blocks.

[0173] The computer program instructions can also be loaded into the computer or other programmable data processing devices, so that a series of operation steps are performed on the computer or other programmable devices to produce a computer-implemented process, so that the instructions executed on the computer or other programmable devices provide a process for realizing the functions specified in the flowcharts and / or block diagrams. Figure 1 The function specified in one or more flows and / or blocks Figure 1steps of the functions specified in the one or more blocks.

[0174] Obviously, the above-mentioned embodiments are only examples for clearly illustrating the present application, and are not intended to limit the present application. Based on the above-mentioned embodiments, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary or possible to enumerate all the embodiments. The obvious changes or variations derived from the above-mentioned embodiments are still within the protection scope of the present application.

Claims

1. A method for evaluating the seismic performance of a dam, characterized in that, The method comprises the following steps: a geometric entity model of a dam is established, and the geometric entity model is discretized by a cross-scale fine grid based on an octree algorithm to obtain a volume grid model; the volume grid model is analyzed by using a nonlinear polyhedral proportional boundary finite element method to establish a finite element model; the volume grid model is subjected to block cone domain integral; a nonlinear stiffness matrix of a polyhedral element is calculated according to a strain displacement conversion matrix and an elastic-plastic constitutive matrix of a material at a domain integral point; the nonlinear stiffness matrix of the polyhedral element is assembled according to degrees of freedom to obtain a total stiffness matrix of the domain; an external force load vector is obtained according to a surface force load vector and a volume force load vector of the polyhedron; an internal force load vector of the polyhedral element is calculated according to a strain displacement conversion matrix and a nonlinear constitutive matrix of a material at the domain integral point; based on the finite element model, a generalized plastic coarse-grained soil constitutive model using a static-rheological-dynamic whole-process unified model is established, and an elastic-plastic back analysis of the generalized plastic coarse-grained soil constitutive model considering long-term deformation of the dam is carried out based on measured data, and the method for establishing the generalized plastic coarse-grained soil constitutive model comprises the following steps: a correlation between a nonlinear degree index of a current stress state and a strain integral step is established according to statistical data, since the nonlinear degree of the material and the load step are inversely proportional; the constitutive integral of the adaptive step is carried out according to the correlation to establish the generalized plastic coarse-grained soil constitutive model; the generalized plastic coarse-grained soil constitutive model using the back analysis result material parameters is subjected to seismic input, and a dam crest seismic subsidence rate is calculated; the dam seismic resistance performance is evaluated according to the dam crest seismic subsidence rate.

2. The method for evaluating seismic performance of a dam according to claim 1, wherein after the volume grid model is obtained, the following steps are further included: nodes at the interfaces between the components are fused and shared.

3. The method of claim 1, wherein, the method for calculating the nonlinear stiffness matrix of the polyhedral element comprises the following steps: for a cubic element in the volume grid model, a similar element acceleration algorithm is used to calculate the nonlinear stiffness matrix of the cubic element: the stiffness matrix of a unit cubic element or the stiffness matrix at the integral point of a unit size element is calculated and stored in advance; based on the stiffness matrix of the unit cubic element or the stiffness matrix at the integral point of the unit size element, the stiffness matrix of an arbitrary cubic element is obtained according to a corresponding proportional coefficient.

4. The method of claim 1, wherein, the method for obtaining the seismic input comprises the following steps: seismic stages are divided into grades according to seismic wave characteristics; different monitoring time steps are used for different grades of seismic stages, wherein the grade of the seismic stage and the monitoring time step are inversely proportional; seismic wave monitoring data are obtained according to the adaptive monitoring time step; the seismic input is obtained by cutting the seismic wave monitoring data according to the Arias intensity.

5. The method of claim 1, wherein, since the dam crest seismic subsidence rate and the dam slope slip amount are positively correlated, the dam slope slip amount is calculated according to the dam crest seismic subsidence rate; if the dam slope slip amount is not higher than a non-failure dam index, the degree of earthquake damage is judged according to the dam crest seismic subsidence rate and a pre-established seismic safety grading evaluation index. ​ 6. A dam seismic performance evaluation device characterized by comprising: ​ The grid model establishing module is configured to establish a geometric entity model of the dam and perform cross-scale fine grid discretization on the geometric entity model based on an octree algorithm to obtain a volume grid model. The finite element module establishing module is configured to analyze the volume grid model by using a nonlinear polyhedral proportional boundary finite element method to establish a finite element model. The volume grid model is subjected to block cone domain integral; The nonlinear stiffness matrix of the polyhedral element is calculated according to the strain displacement conversion matrix and the material elastoplasticity constitutive matrix at the domain integral point; The nonlinear stiffness matrix of the polyhedral element is assembled according to the degrees of freedom to obtain the total stiffness matrix of the domain; The external force load vector is obtained according to the surface force load vector and the volume force load vector of the polyhedron; The internal force load vector of the polyhedral element is calculated according to the strain displacement conversion matrix and the material nonlinear constitutive matrix at the domain integral point; The inversion analysis module is configured to establish a generalized plastic coarse-grained soil constitutive model using a static-rheological-dynamic unified whole-process method based on the finite element model, and perform elastoplastic inversion analysis of the generalized plastic coarse-grained soil constitutive model considering long-term deformation of the dam based on measured data, and the establishment method of the generalized plastic coarse-grained soil constitutive model comprises: Since the material nonlinear degree and the load step length are inversely proportional, the correlation between the current stress state nonlinear degree index and the strain integral step length is established according to statistical data; The generalized plastic coarse-grained soil constitutive model is established by constitutive integration with adaptive step length according to the correlation; The seismic index calculation module is configured to input seismic motion to the generalized plastic coarse-grained soil constitutive model with material parameters obtained by inversion analysis to calculate the dam crest seismic subsidence rate. The seismic performance evaluation module is configured to evaluate the seismic performance of the dam according to the dam crest seismic subsidence rate.

7. A dam seismic performance evaluation apparatus characterized by comprising: It comprises: A memory for storing a computer program; A processor for executing the computer program to realize the steps of the dam seismic performance evaluation method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer program is stored on the computer readable storage medium, and the computer program is executed by the processor to realize the steps of the dam seismic performance evaluation method according to any one of claims 1 to 5.

Images