Seismic wave field simulation spectrum unit modeling method suitable for complex terrain

Abstract

The invention provides an earth crust spectrum unit optimization modeling method suitable for strong seismic wave field simulation under complex topographic conditions, and relates to the field of seismic engineering, and the method comprises the steps: determining topographic parameters of a research area; according to wave velocity structure parameters of a research area, determining a mesh refinement multiple, and obtaining a minimum distance from a wave velocity contour surface to the bottom; determining the position of a refinement conversion layer of the earth crust spectrum unit; determining the total number of three-way units before mesh refinement according to the position of the earth crust spectrum unit refinement conversion layer; carrying out mesh generation in the whole domain by adopting hexahedron units; according to the layer number of the earth crust spectrum units at the upper part of the conversion layer, carrying out superficial earth crust model refinement processing; and calculating grid quality, counting the number of the earth crust spectrum units to obtain an expected value of the earth crust spectrum units, and comparing the expected value with the estimated value. According to the method, the quality problem of the spectrum unit during modeling of the earth crust structure in regions with complex topographic conditions such as alpine and canyon can be solved, meanwhile, the calculation freedom degree is reduced to the minimum, and stable and low-cost seismic oscillation simulation based on the spectrum element method is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of earthquake engineering, and in particular relates to a seismic wave field simulation spectrum unit modeling method suitable for complex terrain. Background Art

[0002] In the seismic design of structures, reasonable seismic motion parameters are the premise for ensuring the seismic safety of structures. For the seismic resistance of important structures such as high dams, large reservoirs, and nuclear power facilities, seismic motion time history is required as input. However, for specific projects, real records that meet similar seismic geological conditions are usually difficult to obtain, so artificial simulation methods are needed to supplement them.

[0003] At present, the commonly used methods for simulating earthquake motion include random methods and physics-based direct simulation methods. Physics-based direct simulation methods (such as finite difference method, finite element method, spectral element method, etc.) can fully consider various influencing factors related to the earthquake source, propagation path, and site, and are naturally reasonable based on the basic physical mechanism of wave propagation. Among them, the spectral element method combines the flexibility of the finite element method with the accuracy and fast convergence of the pseudo-spectral method, and is particularly good at simulating the propagation of earthquake motion in inhomogeneous media and complex terrain conditions.

[0004] Compared with random methods, direct simulation methods based on physics are often computationally intensive. In spectral element seismic simulation, the maximum simulation frequency is proportional to the wave velocity of the medium and inversely proportional to the distance between unit nodes. Therefore, shallow mesh refinement is usually required based on the crustal wave velocity structure to maximize computational efficiency. However, in areas with complex terrain conditions such as high mountains and canyons, steep and complex terrain mutations will degrade the mesh quality, resulting in non-convergence of the simulation process. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a spectral unit modeling method for seismic wave field simulation suitable for complex terrain, which can solve the quality problem of spectral units when modeling crustal structures in areas with complex terrain conditions such as high mountains and canyons, while minimizing the calculation degrees of freedom, thereby realizing stable and low-cost simulation of seismic motion based on the spectral element method.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is: a seismic wave field simulation spectrum unit modeling method suitable for complex terrain, comprising the following steps:

[0007] S1. Determine the topographic parameters of the study area;

[0008] S2. According to the wave velocity structure parameters of the study area, determine the grid refinement multiple and obtain the minimum distance between the wave velocity contour surface and the bottom;

[0009] S3, based on the determined topographic parameters and the minimum distance between the wave velocity isosurface and the bottom, determine the position of the crustal spectrum unit refinement conversion layer;

[0010] S4, according to the position of the conversion layer of the crustal spectrum unit, determine the total number of three-dimensional units before grid refinement;

[0011] S5. Based on the determined topographic parameters of the study area and the total number of three-dimensional cells before mesh refinement, hexahedral cells are used to perform mesh generation in the entire area;

[0012] S6. Refine the shallow crust model according to the number of crustal spectrum units above the conversion layer;

[0013] S7. According to the refinement results, the grid quality is calculated, the number of crustal spectrum units is counted to obtain the expected value of the crustal spectrum unit, and compared with the estimated value to complete the optimization modeling of the crustal spectrum unit.

[0014] The beneficial effect of the present invention is that in areas with complex terrain conditions such as high mountains and canyons, steep and complex terrain mutations will deteriorate the quality of the spectral unit grid, resulting in non-convergence of the spectral element method simulation process. The present invention proposes a spectral unit modeling method for seismic wave field simulation suitable for complex terrain that comprehensively considers the spectral unit quality and the calculation efficiency of the spectral element method. By calculating the sizes of the upper and lower parts of the conversion layer, and using hexahedral units to perform grid division in the entire domain, and calculating the number of crustal spectral units, the optimized modeling processing of the crustal spectral units is achieved. The present invention can simultaneously solve the spectral unit quality problem and minimize the calculation degrees of freedom, thereby achieving stable and low-cost simulation of seismic motion using the spectral element method.

[0015] Furthermore, the step S1 includes the following steps:

[0016] S101, determining a minimum simulation altitude according to a maximum fault depth, and determining a simulation length L and a simulation width W according to a site and a relative position of the fault;

[0017] S102, modeling the terrain structure of the study area, and calculating the simulated height H from the highest point of the terrain altitude to the minimum simulated altitude;

[0018] S103, calculating the elevation difference ΔH between the lowest point and the highest point in the study area, and completing the parameter determination.

[0019] Furthermore, step S2 includes the following steps:

[0020] S201, three-dimensional modeling of the crustal wave velocity structure;

[0021] S202. Based on the modeling results, the surface shear wave velocity V s,0 and the regional maximum wave velocity V s,m , calculate the mesh refinement multiple;

[0022] S203, according to the mesh refinement multiple, calculate the minimum distance between the wave velocity contour surface and the bottom, where the minimum distance is the height H of the constant wave velocity surface r .

[0023] The beneficial effect of the above further scheme is: according to the site surface shear wave velocity V s,0 and the regional maximum wave velocity V s,m , calculating the mesh refinement factor can ensure that all meshes meet the requirements of the maximum simulation frequency.

[0024] Furthermore, the expression of the wave velocity isosurface is as follows:

[0025] V sr =n r ·V s,0

[0026]

[0027] Among them, V sr represents the wave velocity contour surface, n r Represents the grid refinement multiple, and ceil() represents the rounding up function.

[0028] The beneficial effect of the above further solution is that the minimum mesh refinement factor is determined according to the wave velocity, thereby avoiding the reduction of simulation efficiency due to too small a mesh.

[0029] Furthermore, the expression for refining the transition layer position of the crustal spectrum unit in step S3 is as follows:

[0030]

[0031] Among them, H2 represents the depth of the crustal spectrum unit refinement conversion layer, ΔH represents the elevation difference between the lowest point and the highest point in the study area, and C r and C H All represent constants, n r Indicates the grid refinement multiple, and H indicates the simulated height from the highest point of terrain elevation to the minimum simulated elevation.

[0032] The beneficial effect of the above further solution is that the present invention can determine the depth of the conversion layer when the number of units is minimized through the above formula.

[0033] Furthermore, step S4 includes the following steps:

[0034] S401. Calculate the vertical dimension D of the upper part of the crustal spectrum unit conversion layer using the following formula: near :

[0035]

[0036] Among them, D near (f m ) indicates that the maximum frequency to be simulated is f m The vertical dimension of the upper part of the transition layer of the crustal spectrum unit, f m Indicates the maximum frequency to be simulated, N gll Indicates the number of integration points of the crustal spectrum unit, D0 indicates the reference size of the eight-node hexahedral unit when the number of integration points of the crustal spectrum unit is 5, the maximum frequency is 1 Hz, and the surface shear wave velocity is 1000 m / s, V s,0 Represents the surface shear wave velocity at the site, N msh Indicates the number of node segments on the edge of the crustal spectrum unit. For eight-node hexahedral units, N msh =1, twenty-seven-node hexahedral surface element N msh =2;

[0037] S402, according to D near (f m ), the number of crustal spectral units above the transition layer n is calculated using the following formula: z1 :

[0038]

[0039] Among them, H2 represents the depth of the crustal spectrum unit refinement conversion layer;

[0040] S403, according to the number of crustal spectrum units n z1 , the horizontal dimension a1 of the upper part of the crustal spectrum unit transition layer is calculated using the following formula;

[0041]

[0042] Among them, H1 represents the depth from the lowest point of the regional terrain to the transition layer;

[0043] S404. According to the horizontal dimension a1 of the upper part of the crustal spectrum unit conversion layer, the number of horizontal units in the upper part of the conversion layer is calculated using the following formulas: and

[0044]

[0045] Wherein, L represents the simulation length, and W represents the simulation width;

[0046] S405, according to the horizontal dimension a1 of the upper part of the crustal spectrum unit conversion layer, the three-directional unit dimension a2 of the lower part of the conversion layer is calculated using the following formula;

[0047] a2=a1n r

[0048] Among them, nr Indicates the mesh refinement multiple;

[0049] S406. According to the three-dimensional unit size a2, the number of vertical units in the lower part of the conversion layer is calculated using the following formula: z2 :

[0050]

[0051] Where H represents the simulated height from the highest point of terrain elevation to the minimum simulated elevation;

[0052] S407, according to the number of horizontal units n x1 、n y1 and the number of vertical units n z2 , the total number of three-dimensional elements n before mesh refinement is calculated using the following formulas: x 、n y and n z , complete the determination of the crustal spectrum unit size:

[0053]

[0054] Among them, ceil() represents the rounding up function.

[0055] The beneficial effect of the above further solution is that the present invention can conveniently calculate the total number of units and estimate the total degree of freedom of the model by confirming the total number of three-dimensional units before mesh refinement.

[0056] Furthermore, the expression of the expected value of the crustal spectrum unit in step S7 is as follows:

[0057]

[0058] Where n represents the expected value of the crustal spectrum unit, C represents a constant, H2 represents the depth of the crustal spectrum unit refinement conversion layer, ΔH represents the elevation difference between the lowest point and the highest point in the study area, and n r represents the mesh refinement multiple, H represents the simulated height from the highest point of terrain elevation to the minimum simulated elevation, L represents the simulated length, W represents the simulated width, and D near (f m ) indicates that the maximum frequency to be simulated is f m Vertical dimensions of the upper part of the transition layer of the crustal spectrum unit.

[0059] The above further solution has the beneficial effect that the total number of calculated units can be easily compared with other projects, and the total degree of freedom of the model can be estimated. Based on the total number of degrees of freedom and the comparison results with other projects, reasonable computing resources can be allocated for earthquake simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 The present invention is a flow chart of the method.

[0061] Figure 2 It is a schematic diagram of the terrain profile in the present invention.

[0062] Figure 3 It is a schematic diagram of the decomposition of the global spectrum unit in the present invention.

[0063] Figure 4 This is a schematic diagram of the refinement of the shallow crustal unit in the present invention.

[0064] Figure 5 Schematic diagram of the overall skewness of the spectrum unit in this embodiment.

[0065] Figure 6 This is a schematic diagram of three-component earthquake motions simulated by the crustal spectrum unit model using the technical solution of the present invention in this embodiment. DETAILED DESCRIPTION

[0066] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0067] Example

[0068] like Figure 1 As shown, the present invention provides a seismic wave field simulation spectrum unit modeling method suitable for complex terrain, and its implementation method is as follows:

[0069] S1. Determine the terrain parameters of the study area. The implementation method is as follows:

[0070] S101, determining a minimum simulation altitude according to a maximum fault depth, and determining a simulation length L and a simulation width W according to a site and a relative position of the fault;

[0071] S102, modeling the terrain structure of the study area, and calculating the simulated height H from the highest point of the terrain altitude to the minimum simulated altitude;

[0072] S103, calculating the elevation difference ΔH between the lowest point and the highest point in the study area, and completing the parameter determination.

[0073] S2. According to the wave velocity structure parameters of the study area, determine the grid refinement multiple and obtain the minimum distance between the wave velocity contour surface and the bottom. The implementation method is as follows:

[0074] S201, three-dimensional modeling of the crustal wave velocity structure;

[0075] S202. Based on the modeling results, the surface shear wave velocity V s,0 and the regional maximum wave velocity V s,m , calculate the mesh refinement factor:

[0076]

[0077] Among them, ceil() represents the upward rounding function;

[0078] S203, according to the mesh refinement multiple, calculate the minimum distance between the wave velocity contour surface and the bottom, where the minimum distance is the height H of the constant wave velocity surface r ,like Figure 2 As shown;

[0079] V sr =n r ·V s,0 (2)

[0080] Among them, V sr represents the wave velocity contour surface, n r Indicates the mesh refinement multiple;

[0081] S3, based on the determined topographic parameters and the minimum distance between the wave velocity isosurface and the bottom, determine the position of the crustal spectrum unit refinement conversion layer;

[0082] In this embodiment, the key to the present invention is to obtain a depth of H2 from the highest point above sea level (H2>HH r ) is set at a horizontal transition zone so that the spectral unit is relatively flat in this area. If H2 is small, a thin sheet-like unit will be generated near the lowest point of the terrain altitude, and its unit quality is also poor; if H2 is large, the simulation efficiency will be reduced because the density of the upper unit is much greater than that of the lower unit. Therefore, how to choose the depth of H2 so that the overall quality of the crustal spectral unit model is optimal and the simulation scale is minimized is the core of the present invention.

[0083] In this embodiment, the depth H2 of the conversion layer can be obtained by taking the derivative of the total number of upper and lower units of the conversion layer n with respect to H2, and minimizing the simulation scale is equivalent to solving the following equation:

[0084]

[0085] Among them, C r and C H Both represent constants, and ΔH represents the elevation difference between the lowest and highest points in the study area.

[0086]

[0087] Among them, n rIndicates the grid refinement multiple, and H indicates the simulated height from the highest point of terrain elevation to the minimum simulated elevation.

[0088] The following conditions must be met to solve equation (3):

[0089]

[0090] When n r When ≥2, the above formula always holds true. From formula (3), we can get that when H2 takes the following value, the total number of units n has a minimum value:

[0091]

[0092] S4. According to the position of the conversion layer of the crustal spectrum unit refinement, the total number of three-dimensional units before grid refinement is determined. The implementation method is as follows:

[0093] S401. Calculate the vertical dimension D of the upper part of the crustal spectrum unit conversion layer using the following formula: near :

[0094]

[0095] Among them, D near (f m ) indicates that the maximum frequency to be simulated is f m The vertical dimension of the upper part of the transition layer of the crustal spectrum unit, f m Indicates the maximum frequency to be simulated, N gll Indicates the number of integration points of the crustal spectrum unit, D0 indicates the reference size of the eight-node hexahedral unit when the number of integration points of the crustal spectrum unit is 5, the maximum frequency is 1 Hz, and the surface shear wave velocity is 1000 m / s, V s,0 Represents the surface shear wave velocity at the site, N msh Indicates the number of node segments on the edge of the crustal spectrum unit. For eight-node hexahedral units, N msh =1, twenty-seven-node hexahedral surface element N msh =2;

[0096] S402, according to D near (f m ), the number of crustal spectral units above the transition layer n is calculated using the following formula: z1 :

[0097]

[0098] Among them, H2 represents the depth of the crustal spectrum unit refinement conversion layer;

[0099] S403, according to the number of crustal spectrum units n z1, the horizontal dimension a1 of the upper part of the crustal spectrum unit conversion layer is calculated using the following formula. In this embodiment, the horizontal dimension a1 on the unit conversion layer is the same as the vertical dimension of the unit at the average terrain elevation, that is:

[0100]

[0101] Among them, H1 represents the depth from the lowest point of the regional terrain to the transition layer;

[0102] S404. According to the horizontal dimension a1 of the upper part of the crustal spectrum unit conversion layer, the number of horizontal units in the upper part of the conversion layer is calculated using the following formulas: and

[0103]

[0104] Wherein, L represents the simulation length, and W represents the simulation width;

[0105] S405, according to the horizontal dimension a1 of the upper part of the crustal spectrum unit conversion layer, the three-directional unit dimension a2 of the lower part of the conversion layer is calculated using the following formula;

[0106] a2=a1n r (13)

[0107] Among them, n r Indicates the mesh refinement multiple;

[0108] S406. According to the three-dimensional unit size a2, the number of vertical units in the lower part of the conversion layer is calculated using the following formula: z2 :

[0109]

[0110] Where H represents the simulated height from the highest point of terrain elevation to the minimum simulated elevation;

[0111] S407, according to the number of horizontal units n x1 、n y1 and the number of vertical units n z2 , the total number of three-dimensional elements n before mesh refinement is calculated using the following formulas: x 、n y and n z , complete the determination of the crustal spectrum unit size:

[0112]

[0113] Among them, ceil() represents the rounding up function.

[0114] S5. Based on the determined topographic parameters of the study area and the total number of three-dimensional cells before mesh refinement, hexahedral cells are used to perform mesh generation in the entire area;

[0115] In this embodiment, according to the determined terrain parameters and the determined total number of three-dimensional units, hexahedral units are used to perform meshing in the entire domain, and the results are as follows: Figure 3 shown.

[0116] S6. Refine the shallow crust model according to the number of crustal spectrum units above the conversion layer;

[0117] In this embodiment, the shallow crust model is refined according to the determined number of upper unit layers of the transition layer, and the result is as follows: Figure 4 shown.

[0118] S7. According to the refinement results, the grid quality is calculated, the number of crustal spectrum units is counted to obtain the expected value of the crustal spectrum unit, and compared with the estimated value to complete the optimization modeling of the crustal spectrum unit. The expression of the expected value of the crustal spectrum unit is as follows:

[0119]

[0120] Where n represents the expected value of the crustal spectrum unit, C represents a constant, H2 represents the depth of the crustal spectrum unit refinement conversion layer, ΔH represents the elevation difference between the lowest point and the highest point in the study area, and n r represents the mesh refinement multiple, H represents the simulated height from the highest point of terrain elevation to the minimum simulated elevation, L represents the simulated length, W represents the simulated width, and D near (f m ) indicates that the maximum frequency to be simulated is f m Vertical dimensions of the upper part of the transition layer of the crustal spectrum unit.

[0121] In this embodiment, Figure 5 As shown, the skewness distribution of the spectral unit using the technical solution of the present invention under complex terrain conditions is given. It can be seen that the maximum value of the unit skewness under complex terrain conditions is 0.708, which is less than the maximum limit of the spectral element method software specfem3D, that is, the model can directly simulate seismic motion without any additional processing, ensuring the stability and efficiency of the simulation.

[0122] In this embodiment, the number of spectral unit model units obtained by the technical solution of the present invention is relatively small, and the total number of spectral units of the technical solution of the present invention is 899232. The existing solution can correctly perform spectral element method simulation with 50% more total units than the technical solution of the present invention. The technical solution of the present invention significantly improves the simulation efficiency and saves about half of the simulation cost.

[0123] In this embodiment, the model obtained by the technical solution of the present invention can be directly used for spectral element method simulation, such as Figure 6 As shown, Figure 6 The three-component seismic motion of the site obtained by spectral element method simulation using the crustal spectral unit model of the technical solution of the present invention is given, and its maximum effective frequency meets the set target value, and there is no non-convergence in the simulation process.

Claims

1. A spectral unit modeling method for seismic wave field simulation suitable for complex terrain, characterized in that: The following steps are involved: S1. Determine the topographic parameters of the study area; S2. According to the wave velocity structure parameters of the study area, determine the grid refinement multiple and obtain the minimum distance between the wave velocity contour surface and the bottom; S3, based on the determined topographic parameters and the minimum distance between the wave velocity isosurface and the bottom, determine the position of the crustal spectrum unit refinement conversion layer; S4, according to the position of the conversion layer of the crustal spectrum unit, determine the total number of three-dimensional units before grid refinement; S5. Based on the determined topographic parameters of the study area and the total number of three-dimensional cells before mesh refinement, hexahedral cells are used to perform mesh generation in the entire area; S6. Refine the shallow crust model according to the number of crustal spectrum units above the conversion layer; S7. According to the refinement results, the grid quality is calculated, the number of crustal spectrum units is counted to obtain the expected value of the crustal spectrum unit, and compared with the estimated value to complete the optimization modeling of the crustal spectrum unit.

2. The method for modeling seismic wave field simulation spectrum units suitable for complex terrain according to claim 1, characterized in that: The step S1 comprises the following steps: S101, determining a minimum simulation altitude according to a maximum fault depth, and determining a simulation length L and a simulation width W according to a site and a relative position of the fault; S102, modeling the terrain structure of the study area, and calculating the simulated height H from the highest point of the terrain altitude to the minimum simulated altitude; S103, calculating the elevation difference ΔH between the lowest point and the highest point in the study area, and completing the parameter determination.

3. The method for modeling seismic wave field simulation spectrum units suitable for complex terrain according to claim 1, characterized in that: The step S2 comprises the following steps: S201, three-dimensional modeling of the crustal wave velocity structure; S202. Based on the modeling results, the surface shear wave velocity V s,0 and the regional maximum wave velocity V s,m , calculate the mesh refinement multiple; S203, according to the mesh refinement multiple, calculate the minimum distance between the wave velocity contour surface and the bottom, where the minimum distance is the height H of the constant wave velocity surface r .

4. The method for modeling a seismic wave field simulation spectrum unit suitable for complex terrain according to claim 3, characterized in that: The expression of the wave velocity isosurface is as follows: V sr =n r ·V s,0 Among them, V sr represents the wave velocity contour surface, n r Represents the grid refinement multiple, and ceil() represents the rounding up function.

5. The method for modeling seismic wave field simulation spectrum units suitable for complex terrain according to claim 1, characterized in that: The expression for refining the conversion layer position of the crustal spectrum unit in step S3 is as follows: Among them, H2 represents the depth of the crustal spectrum unit refinement conversion layer, ΔH represents the elevation difference between the lowest point and the highest point in the study area, and C r and C H All represent constants, n r Indicates the grid refinement multiple, and H indicates the simulated height from the highest point of terrain elevation to the minimum simulated elevation.

6. The method for modeling seismic wave field simulation spectrum units suitable for complex terrain according to claim 1, characterized in that: The step S4 comprises the following steps: S401. Calculate the vertical dimension D of the upper part of the crustal spectrum unit conversion layer using the following formula: near : Among them, D near (f m ) indicates that the maximum frequency to be simulated is f m The vertical dimension of the upper part of the transition layer of the crustal spectrum unit, f m Indicates the maximum frequency to be simulated, N gll Indicates the number of integration points of the crustal spectrum unit, D0 indicates the reference size of the eight-node hexahedral unit when the number of integration points of the crustal spectrum unit is 5, the maximum frequency is 1 Hz, and the surface shear wave velocity is 1000 m / s, V s,0 Represents the surface shear wave velocity at the site, N msh Indicates the number of node segments on the edge of the crustal spectrum unit. For eight-node hexahedral units, N msh =1, twenty-seven-node hexahedral surface element N msh =2; S402, according to D near (f m ), the number of crustal spectral units above the transition layer n is calculated using the following formula: z1 : Among them, H2 represents the depth of the crustal spectrum unit refinement conversion layer; S403, according to the number of crustal spectrum units n z1 , the horizontal dimension a1 of the upper part of the crustal spectrum unit transition layer is calculated using the following formula; Among them, H1 represents the depth from the lowest point of the regional terrain to the transition layer; S404. According to the horizontal dimension a1 of the upper part of the crustal spectrum unit conversion layer, the number of horizontal units in the upper part of the conversion layer is calculated using the following formulas: and Wherein, L represents the simulation length, and W represents the simulation width; S405, according to the horizontal dimension a1 of the upper part of the crustal spectrum unit conversion layer, the three-directional unit dimension a2 of the lower part of the conversion layer is calculated using the following formula; <h2 style=";text-align:left;direction:ltr">a2=a1n<h2 style=";text-align:left;direction:ltr"> r Among them, n r Indicates the mesh refinement multiple; S406. According to the three-dimensional unit size a2, the number of vertical units in the lower part of the conversion layer is calculated using the following formula: z2 : Where H represents the simulated height from the highest point of terrain elevation to the minimum simulated elevation; S407, according to the number of horizontal units and the number of vertical units n z2 , the total number of three-dimensional elements n before mesh refinement is calculated using the following formulas: x 、n y and n z , complete the determination of the crustal spectrum unit size: Among them, ceil() represents the rounding up function.

7. The method for modeling seismic wave field simulation spectrum units suitable for complex terrain according to claim 1, characterized in that: The expression of the expected value of the crustal spectrum unit in step S7 is as follows: Where n represents the expected value of the crustal spectrum unit, C represents a constant, H2 represents the depth of the crustal spectrum unit refinement conversion layer, ΔH represents the elevation difference between the lowest point and the highest point in the study area, and n r represents the mesh refinement multiple, H represents the simulated height from the highest point of terrain elevation to the minimum simulated elevation, L represents the simulated length, W represents the simulated width, and D near (f m ) indicates that the maximum frequency to be simulated is f m Vertical dimensions of the upper part of the transition layer of the crustal spectrum unit.

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