JP3398659B2 - Geological wave propagation simulation system and its recording medium - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a geological wave propagation simulation system and its recording medium, and
In the geological wave propagation analysis, the present invention relates to a geological wave propagation simulation system in which the analysis is made efficient by using the homogenization of the mesh in the finite element method analysis, and to a recording medium in which a program for realizing the geological wave propagation simulation system is recorded.

[0002]

2. Description of the Related Art For example, a strong earthquake area that occurs when an earthquake occurs
It is often dependent on local geological structure, as represented by the Hyogoken Nanbu Earthquake. Therefore, at present, it is urgent to elucidate the relationship between the geological structure and the strong earthquake region. Therefore, in order to clarify the relationship, it is necessary to analyze the geological wave propagation.
This geological wave propagation analysis is very large-scale.
However, in order to realize this analysis, a high-speed and large-capacity computer is required, and the performance of the current computer is poor in feasibility.

Although there is general-purpose geological wave propagation analysis software, it is not a simulation system or simulation software specialized for geological wave propagation. Since this geological wave propagation analysis is a very large-scale analysis, it is a simple analysis that performs a two-dimensional analysis using the finite element method in the vertical direction, that is, the depth direction. In addition, a method of observing the vibration of the ground surface and performing the propagation analysis of the geological wave considering the empirical experimental data is also easily adopted for the geological wave propagation analysis.

[0004]

However, since these methods cannot perform accurate three-dimensional analysis,
It was difficult to elucidate the behavior of wave propagation especially in complicated geological structures. If the finite element method is applied to this three-dimensional analysis, in addition to computer problems, the input of mesh shape parameters related to the area where the geological model is meshed becomes enormous, so the operator's workload is measured. It becomes unknown.

Further, even if the geological structure exploration using the wave echo is used, the propagation behavior of the echo has not been sufficiently clarified, so that it is difficult to analyze a complicated geological structure. Therefore, the present invention is to specialize in geological wave propagation analysis, to easily perform three-dimensional analysis using the finite element method, and to construct a geological wave propagation simulation system in which the workload of the operator is reduced, and the simulation system thereof. An object of the present invention is to provide a recording medium in which a program for executing is recorded.

[0006]

In order to solve the above problems, in the present invention, in the geological wave propagation simulation system for performing the wave propagation analysis of the geological model by the finite element method, the geology of the geological wave propagation is targeted. and geological model creation means for creating a model, you in the geological model
And geologic property values defining means for respectively defining the geological property values for a plurality of regions kicking, the source model creation means for creating a source model to be input to the geological model, the geological model of the geologic property values are defined A display for displaying a simulation execution means for automatically creating a uniform mesh for a region and executing a geological wave propagation simulation according to the hypocenter model and analysis conditions using the mesh, the geological model, and an analysis result by the simulation execution means. And means.

The display means has a GUI operation screen, and in accordance with the display of the operation screen, at least the geological model is created, the geological property value is defined, the seismic source model is created, the analysis condition is defined, and the simulation is performed. Enabled execution instructions. Further, the simulation executing means automatically creates a uniform mesh for the area of the geological model in which the fitted geophysical property values are the same,
The uniform meshes having different mesh sizes were created for the fitted regions of the geological model having different geological property values, and the shape of the uniform mesh was made into a regular cube.

Further, the geological model creating means automatically creates a three-dimensional geological model based on depth boundary stratum boundary data from a plurality of ground surface positions, and uses the stratum boundary data as boring data, or A three-dimensional geological model is created based on the stored geological model data. Further, the geophysical property value defining means is to create the geophysical property value by complementing the seismic velocity gradient in the depth direction of the ground with a continuous function.

The source model creating means creates the source model by inputting a fault rupture process, by inputting spatial and temporal distribution behavior with respect to slip on the fault surface, and further by inputting a predetermined earthquake waveform. Thus, a point source model is created at a designated position in the geological model. The display means can display the seismic motion waveform at a designated position on the ground surface of the geological model, or can display the seismic wave propagation map on the designated surface in the geological model as an animation.

Further, according to the present invention, in a program recording medium in which a program for executing geological wave propagation simulation of the geological model is recorded by a finite element method analysis, a geological model which is a target of geological wave propagation is created, and the geological model is created. geological property values respectively defined for the plurality of regions in the middle, to create a source model to be input to the geological model, automatically creates a uniform mesh for the region of the said geological model geological property values is defined, the Using a mesh, a geological wave propagation simulation was executed according to the hypocenter model and analysis conditions, and a program for displaying the geological model and the analysis result by the simulation executing means was recorded.

Then, according to the display of the GUI operation screen,
A program recording medium for at least creating the geological model, defining the geophysical property values, creating the epicenter model, defining the analysis conditions, instructing simulation execution, and displaying analysis results. Further, a uniform mesh is automatically created for the regions of the geological model having the same fitted geological property value, and the sizes of the meshes are different for the regions of the geological model having different fitted geological property values. The uniform mesh program was recorded.

Further, a three-dimensional geological model is automatically created based on depth boundary data from a plurality of ground surface positions, and the seismic velocity gradient in the ground depth direction is complemented by a continuous function to obtain the geology. Create physical property values. Then, the source model can be created by inputting the fault rupture process, by inputting the spatial and temporal distribution behavior with respect to the slip on the fault plane, or by inputting a predetermined seismic waveform, and the specified position in the geological model can be created. A program that can create a point source model was recorded on a recording medium.

Further, a program capable of displaying a seismic motion waveform at a designated position on the ground surface of the geological model or displaying a seismic wave propagation map on a designated surface in the geological model as an animation is recorded on a recording medium. did.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A geological wave propagation simulation system according to this embodiment will be described below.
In the geological wave propagation simulation system of the present embodiment, various data can be input according to an operation screen by a graphical user interface (GUI) for a series of analysis work, creation of a geological model, definition of geophysical property values, and source model calculation. Creation, definition of analysis conditions, execution of analysis, and display of analysis results were made possible. Furthermore, by adopting the finite element method for this analysis and automatically generating a uniform mesh for the geological structure object to be analyzed, it is possible to simplify the three-dimensional analysis of the geological model. It facilitates realization of geological wave propagation simulation system.

A schematic block diagram of the geological wave propagation simulation system of this embodiment is shown in FIG. The geological wave propagation simulation system includes a control unit 1 including a CPU, a storage unit 2, a database unit 3, a display unit 4,
The operation unit 5, the output unit 6, and the transmission / reception unit 7 are included.

In addition to the operation program for driving the simulation system, the storage means 2 is for executing geological model creation, geological property value definition, seismic source model creation, analysis condition definition / analysis execution, and result display, respectively. Each program of is stored. Further, the database means 3 can store geological model data, boring data, and other geological property value data and vibration waveform data necessary for executing the above-mentioned programs, and also image file data.

The display means 4 has a display screen and displays a screen on which a GUI can be operated when the simulation system is executed. The operation unit 5 is a mouse, a keyboard or the like, and an operator inputs data or performs a pointer on the screen according to the GUI operation screen. In addition, a method using a touch screen can be included.

The output means 6 is for making a hard copy of the information displayed on the screen of the display means 4 by a printer or the like as required. The transmission / reception means 7 is an interface for transmitting / receiving data and the like between this simulation system and the outside. For example, when a personal computer incorporating this system is connected to another personal computer or a server by LAN, or when it is connected to the Internet, This is necessary when connecting to a wireless communication information terminal.

In the system configuration shown in FIG. 1, the personal computer has the storage means 2 and the database means 3 built therein. However, depending on the built-in memory capacity, the server connected to the LAN may be The storage means 2 and the database means 3 may be installed. In this case, the personal computer is provided with memory means necessary for system operation, and download or upload is performed via the transmission / reception means 7 when the simulation is executed.

The control means 1 controls each means in executing the geological wave propagation simulation.
According to the operation instruction input from the operation means 5, each data is read from the storage means 2 or the database means 3, a geological wave propagation simulation is executed, and a GUI operation screen is displayed on the display means 4, and the simulation is analyzed. The result is output to the display means 4, the database means 3 or the output means 6.

Here, in the present embodiment, by adopting the finite element method analysis by automatically generating a uniform mesh in the finite element method, the simulation of geological wave propagation can be easily executed by GUI operation. Explain what happened. The formula of the finite element method used in the geological wave propagation simulation of this embodiment is as follows.

[M] [u2] + [C] [u1] + [K] [u] = [P] (1) where [M], [C], and [K] are mass matrices,
Damping matrix, stiffness matrix, [u2], [u1],
[u] are an acceleration vector, a velocity vector, and a displacement vector, respectively. In addition, [P] is an external force vector.
Therefore, when the equation (1) is discretized in the time direction at intervals of dt, the displacement u _{t + dt} at the time _{t + dt} is expressed by the following equation.

[U _{t + dt} ] = [(dt) ² · [P _t ] + (2 [M] −dt · [C] − (dt) ² · [K]) · [u _t ] + (dt・ [C]-[M]) ・ [ut _-dt ]] / [M] (2) Here, if lumped mass is adopted, [M] in equation (2)
^-1 becomes a diagonal matrix, and the displacement u _{t + dt} can be calculated by the explicit method. In the finite element method analysis adopted in this embodiment, when a mesh is generated
In an arbitrary region designated by the user that is considered necessary for analysis efficiency, the shape is a uniform mesh, for example, a cube. In the same stratum, the parameters of the stratum are assumed to be uniform, and the uniformity of the stratum is also used during the analysis to improve the efficiency of the analysis.

However, when a mesh is generated with this cubic shape for a stratum and a ground surface whose stratum conditions change, the mesh size is sufficiently large compared with the seismic motion wavelength, although it becomes stepwise at the boundary of each model. By making it small, the effect can be made small enough to be ignored. For this mesh size, a fine uniform mesh is used for the sedimentary layer with slow sound propagation, and a coarse uniform mesh is used for the rock layer with fast sound propagation to improve efficiency.

At the boundaries of regions having different mesh sizes, the boundary conditions can be satisfied by interpolating the nodal forces on the boundaries up to the nodes on the other boundaries and superposing them at each time step. . Here, in the conventional finite element method, the mass matrix shown in Equation (2) is used.
With respect to [M] _ij , damping matrix [C] _ij , and stiffness matrix [K] _ij , it is necessary to hold configuration parameters for the mesh shape for each mesh. The constituent parameters can be expressed by the following equation.

F (S ₁ , S ₂ , ..., S _n , [N ₁ , ..., N _k ] ₁ , [N ₁ , ..., N _l ] ₂ , ..., [N ₁ , ..., N _m ] _n ) (3) where S ₁ , S ₂ , ..., S _n are parameters of mass, damping, and rigidity for n uniform physical property value regions in the analysis region, and increase in proportion to the number of regions. Is. In addition, [N
₁ , ..., N _k ] ₁ , [N ₁ , ..., N _l ] ₂ , ..., [N ₁ , ..., N _m ] _n are the n uniform physical property value regions, each of which has individual parameters related to the mesh shape. The state is shown to be present, and increases in proportion to the number of meshes.

As described above, when performing the analysis by the conventional finite element method, it is understood that the parameters regarding the mesh shape must be prepared for all the meshes in the analysis area. These parameters must be manually input by the operator and consume a huge amount of memory. Therefore, in the finite element method adopted in the present embodiment, as shown by the following equation, regarding the mass matrix [M] _ij , the damping matrix [C] _ij , and the stiffness matrix [K] _ij , The uniform physical property value area is maintained.

F (S ₁ , S ₂ , ..., S _n , [N ₁ ] ₁ ,, [N ₁ ] ₂ , ..., [N ₁ ] _n ) (4) Here, S ₁ , S ₂ , ..., S _n is a mass, damping and stiffness parameter for each uniform physical property value area, and increases in proportion to the number of areas. Furthermore, [N ₁ ] ₁ , [N ₁ ] ₂ , ..., [N ₁ ] _n
Indicates a parameter relating to the mesh shape of n pieces of uniform physical property value areas, which increases in proportion to the number of uniform physical property value areas.

Comparing the equations (4) and (3), it is greatly different from the analysis by the conventional finite element method. In the conventional method, each mesh of the n uniform physical property value regions relates to the mesh shape. Whereas, in the finite element method analysis of the present embodiment, the parameters for the individual meshes of the n uniform physical property value regions are equal in the uniform physical property value region, and the parameters for one mesh are used.

This is realized by dividing the same stratum with, for example, a regular cube-shaped uniform mesh, and the parameters relating to the mesh shape are compressed for each uniform mesh region as shown in equation (4). . Therefore, holding these matrices requires at most a memory proportional to the number of uniform areas. Further, since the parameters relating to the mesh shape can be expanded and used at the time of calculation for each time step shown in the mathematical expression (2), the analysis can be efficiently performed. An outline of the flow of the analysis process using the finite element method using the uniform mesh described above is shown in FIG.

First, the conditions necessary for the analysis of the geological wave propagation simulation, that is, the simulation execution time and the simulation output interval dt are read (step a), and the mass matrix is calculated according to equation (4).
[M] _ij , damping matrix [C] _ij , and stiffness matrix [K] _ij are compressed in a uniform mesh (step b). Every time the read interval dt is updated (step c), the displacement u _{t + dt} on the mesh represented by the equation (2) is calculated by using the mass matrix [M] _ij , the damping matrix [C] _ij , and the stiffness matrix.
Calculation is performed by sequentially expanding [K] _ij (step d).

Then, until the simulation time is reached, the time is updated at intervals dt to calculate the displacement (step e), and when the time is reached (Y), the analysis process is ended. If the simulation time has not yet been reached (N), the calculation of the displacement is continued while updating the time for each interval dt until returning to step e and reaching the simulation time.

The displacement u obtained by such calculation
The state of geological wave propagation can be displayed on the GUI screen based on _{t + dt} . FIG. 3 shows a procedure of operation processing of the geological wave propagation simulation system adopting the finite element method using the uniform mesh described above. And
Corresponding to the procedure, specific examples of the GUI operation screen displayed on the display means 4 are shown in FIGS. 4 to 12.

Next, with reference to these figures, an operation process of the geological wave propagation simulation system according to the present embodiment will be described. The operation process of the geological wave propagation simulation system includes the steps of creating a geological model, defining geophysical property values, creating a hypocenter model, defining analysis conditions and executing analysis, and displaying results. Therefore, when the operator operates the operation means 5 to activate the geological wave propagation simulation system, the control means 1
Reads the operation program from the storage means 2 and displays the initial screen of the system on the display means 4 as shown in FIG. On the displayed screen, a title of "geologic wave propagation simulation system", a menu field M, and an operation processing window W are displayed.

In the menu column M, a list of operation menus M1 to M5 required for simulation is displayed. M
1 to M5 are iconized, and the operation means 5 can be operated to sequentially select and instruct. M1 is "creation of geological model", M2 is "definition of geophysical property values", M3
Indicates "creation of epicenter model", M4 indicates "definition of analysis conditions and analysis execution", and M5 indicates "result display". When selecting and instructing these icons M1 to M5,
The control means 1 reads the corresponding operation processing program selected and instructed from the storage means 2 and executes the program. Further, the necessary GUI operation screen is displayed on the display means 4. In each figure, the icon selected on the screen is shown in a bold frame.

As a first procedure by the operator,
When the "Make geological model" icon M1 is selected,
The control means 1 reads the geological model creation program stored in the storage means 2 and displays the window W1 on the screen of the display means 4 as shown in FIG. 5 (step S1). The geological model creation program has a function of automatically creating a three-dimensional geological model by inputting geological boundary data in the depth direction from the ground surface based on the acquired boring data and the like. The created geological model can be stored in the geological model database DB1 in the database means 3, and the database DB1 can be reused.

In the displayed window W1, a menu of operation processing required for creating a geological model is displayed. The menus are "Registration of geological model data", "Read geological model data", "Create geological model data" and "Display geological model data". When the icon "geological model data registration" is selected and instructed, the boring data or the like can be input, or when the icon "geological model data read" is selected, the geological model data is read from the database DB1 stored in the database means 3. be able to.

In the window W1 of FIG. 5, the icon "Geological model data creation" is selected to show the automatic creation of the geological model data. 1 to N
A geological model composed of the first to fourth layers is automatically created from the geological boundary data in the depth direction input for No. No. described in the stratum model 1 to No.
6 represents the position of the input boring data.

When the icon "Display geological model data" is selected and instructed, a four-layered geological model is displayed in the window W1. Now that the geological model has been created,
Geophysical property values for each layer constituting the geological model are defined (step S2). As shown in FIG. 6, when the operator selects and instructs the “definition of geophysical property value” of the icon M2, the control means 1 reads the geophysical property value definition program stored in the storage means 2 and displays it. The window W2 is displayed on the screen of No. 4.

This geophysical property value definition program has a function of defining physical property values such as sound propagation velocity in the stratum or material rigidity and density for each layer, and the input physical property values are stored in the geophysical property value database DB2. Means 3
Can be stored in. Then, it has a function of associating the physical property value of the specified region in the geological model with the input physical property value, and further, a function of complementing the seismic velocity gradient in the ground depth direction with a continuous function to create a physical property value, and , And has a function of displaying the supplemented seismic velocity gradient in the window W2.

FIG. 6 shows a process of defining physical property values for each layer in the created stratum model. The window W2 when the icon "read geological property value data" is selected and instructed is displayed. The geophysical properties for each layer are selected from, for example, bedrock, sedimentary layer 1, sedimentary layer 2, sedimentary layer 3, and the like, and are associated with various layers. The figure shows a state in which "rock bed" is selected and instructed for the first layer, which is the lowest layer. When the geophysical properties are associated with all the geological formations, the physical property values regarding the designated geological physical properties are read from the geological physical property database DB2, and the physical property values are associated with the geological formation.

When the physical property values of each layer in the created geological model are defined, the preparation of a hypocenter model is started (step S3). Icon M3 by operator
When "create a hypocenter model" is selected and instructed, the control means 1 reads out the epicenter model creation program from the storage means 2 and, as shown in FIG.
Is displayed.

The hypocenter model creating program has a function of creating a hypocenter model by inputting a fault rupture process relating to a fault plane specified along the depth direction, for example. Further, it has a function of modeling a plurality of point epicenters at a position where an artificial earthquake is generated by geological exploration and a function of inputting arbitrary seismic waveforms. Then, in creating an earthquake model, the spatial and temporal distribution behavior with respect to slip on the fault plane can be input by inputting the rupture vibration waveform at each position on the fault plane in the time history.

The window W3 in FIG. 7 shows a state in which the tomographic plane position on the xy axis plane is specified.
The range of the fault plane is shown by the dotted line. A window W4 in FIG. 8 shows a state in which the time history variation of the fault plane slip distribution is input for the fault plane shown in the window W3. For the fault plane, time t1, t
The slip state in the fault plane at 2 and t3 is entered with an arrow. For multiple point hypocenters, their positions can be entered in the same way as when creating a hypocenter model by fault plane slip.

In the operation processing up to this point, it was possible to define the geophysical properties of the strata constituting the created geological model and input the hypocenter model to be assumed in the geological model. Here, the analysis processing in the geological wave propagation simulation is started (step S
4). Therefore, when the operator selects and instructs the "definition of analysis conditions and analysis execution" of the icon M4,
The control means 1 reads an analysis condition definition / analysis execution program from the storage means 2 and executes the program. Then, the window W5 is displayed on the display means 4.

In the window W5, an input field for defining the simulation time and an input field for defining the simulation output interval are displayed. FIG. 9 shows a state in which the simulation time is 20 seconds and the simulation output interval is 0.5 seconds. Further, in the window W5, an icon “input of seismic-motion waveform sampling position” is displayed in order to specify a position where the seismic-motion waveform is to be sampled as a simulation result. Select and instruct this icon to select the collection position ID1,
After inputting ID2 and ID3, select the icon "Display seismic wave waveform sampling position" to specify the specified sampling position ID
1, ID2, and ID3 are entered on the created geological model, and the geological model is displayed in the [seismic motion waveform sampling position] column of the window W5. With this, it is possible to easily grasp where in the geological model the sampling position is.

Since the analysis conditions for the geological wave propagation simulation could be defined in this way,
Icon "execute analysis" displayed in window W5
Select and instruct. The control means 1 receives the instruction of “analysis execution” and starts the analysis according to the analysis condition definition / analysis execution program read from the storage means 2. Therefore, in order to analyze the created geological model by the finite element method using the uniform mesh described above, the automatic mesh generation process is executed. In this automatic generation process, for each layer that makes up the geological model, according to the defined geophysical properties,
A uniform mesh having a size set in advance corresponding to these geophysical properties is fitted.

A geological model fitted with a uniform mesh is shown in the [Automatic finite element mesh generation] column of the window W6 in FIG. In the geological model shown in FIG. 10, the geological model is divided into a region 1 and a region 2,
The second to fourth layers composed of the sedimentary layers are defined as the area 1, and the first layer composed of bedrock is defined as the area 2. This is the case, for example, when the mesh size is determined by the difference in the velocity of sound propagation. In the sedimentary layer, the sound propagation is slow, so the mesh size is small, and in the bedrock, it is large, so it is large. I am doing it.

When the formation model automatically meshed in this manner is confirmed in the window 6 and the displayed icon "OK" is selected and instructed, the finite element method mesh automatic generation is terminated. The control means 1 receives the instruction of this understanding, calculates according to the analysis processing flow by the uniform mesh finite element method shown in FIG. 2, and executes the analysis. Then
When the operator selects and selects "result display" of the icon M5, the control means 1 outputs the result analyzed in step S4 to the screen of the display means 4 according to the result display program stored in the storage means 2. Yes (step S5).

This result display program has a function of displaying a seismic motion waveform and a seismic wave propagation map at a specified position based on the analysis result, and further has a function of animating the created seismic wave propagation map image. Then, the created image file data DB3 is stored in the database means 3
Can be stored in. The seismic wave propagation map output also has the function of adjusting the contour level.

FIG. 11 shows an example of a screen displaying the analysis result. In the window W7 of the screen, icons "earthquake motion waveform" and "seismic wave propagation map" are displayed, and the result display can be selected. Window W7 shows the case where "earthquake motion waveform" is selected. Figure 9
Corresponding to the seismic-motion waveform sampling positions ID1, ID2, and ID3 designated in the window W5 shown in, the seismic-motion waveform chart at that position is displayed on the time axis.

When the icon "seismic wave propagation map" is selected and instructed, the control means 1 receives this instruction and displays the window W8 as shown in FIG. In the window W8, in the [Seismic wave propagation map] column, the ground surface in the created stratum model and the designated y of the stratum model
The propagation state is displayed in the depth direction in the xz axis plane at the axial position.

The window W8 is displayed according to the analysis conditions defined in step S4, and the displayed seismic wave propagation diagram shows the propagation state after 10.5 seconds. Then, in order to animate this propagation state, select the icon "Next" and output interval 0.
The state of seismic wave propagation is continuously displayed every 5 seconds. Further, in the window W8, the image file related to this seismic wave propagation map is displayed as a result output file symbol "C-OUT10".
5 ”is displayed as being stored in the database means 3. If you enter this symbol, the window W8
This seismic wave propagation map can be displayed again.

As described above, the series of processing steps in the geological wave propagation simulation are divided into the steps of geological model creation, geophysical property value definition, hypocenter model creation, analysis condition definition and analysis execution, and result display. The description has been given with reference to a specific window display example on the display screen. Next, the processing procedure of each step will be described with reference to the flowcharts shown in FIGS.

FIG. 13 shows a processing flow relating to the creation of the geological model in step S1 shown in FIG. First, when the geological model data DB1 is stored in the database means 3 (step S11), the icon "read geological model data" displayed in the window W1 is selected (Y), and data is read from the geological model data DB1. Read (step S12), and proceed to the next step S13. If the geological model database is not stored (N), the process immediately proceeds to the next step S13.

In step S13, in order to create a geological model consisting of various layers to be simulated this time, the database DB4 such as boring data stored in the database means 3 is read in the depth direction from the ground surface. Enter the boundary position of the stratum.
Therefore, when the boundary position of the stratum is input, the boundary surface of each stratum can be calculated (step S14).

Then, as shown in the window W1, for the first to fourth layers in the geological model, the boundary surfaces of these layers are specified, and the boundaries are three-dimensionally displayed (step S15). For all geological layers of the geological model, the process returns to step S13 to perform modeling until the processing is completed (step S16). When the modeling is completed for this geological model (Y), the geological model data obtained here is stored in the database. It is stored in the means 3 as a geological model database DB1 (step S1).
7). When the storage is completed, the geological model creation process in step S1 ends.

Next, when the geological model is created, the process proceeds to step S2, and the process relating to the definition of the geological physical property value is performed. The processing flow is shown in FIG. First, in the created geological model, if the geological property value is not particularly defined (N in step S21), the predetermined physical property value data is read from the geological property value database DB2 stored in the database means 3. The geological model is associated with each layer (step S25).

On the other hand, when defining the geophysical property values for the created geological model (Y in step S21), the speed of sound is defined (step S22). At this time, the input data such as the speed of sound is stored in the geophysical property value database DB2. Furthermore, when the seismic velocity gradient is defined (step 23), the seismic velocity gradient is defined (step S24), and the defined seismic velocity gradient is defined as the geophysical property value, as in the definition of the sound velocity. It is stored in the database DB2.

Then, the physical property value defined here or a predetermined physical property value from the geological property value database DB2 is applied to the model region of the created geological model (step S25). Therefore, when the physical property value is fitted into the area of the geological model, the physical property value is displayed (step S26).
Until the physical property values are fitted to the entire area of the geological model, the process returns to step S25, the physical property value fitting process is performed, and the geological physical property value definition process ends.

When the fitting of the physical property values to the model area of the created geological model is completed, the process goes to the hypocenter model creating process of step S3. The flow of this epicenter model creation processing is shown in FIG. The hypocenter model creation process is divided into the creation of a fault plane rupture model and the creation of a point epicenter model.

In the case of creating the tomographic plane destruction model, the tomographic plane is defined as shown in the window W3 (step S31). Next, the epicenter distribution on this fault plane is defined (step S32). In the example shown in the window W4, the fault plane slip distribution is input as a hypocenter distribution by time-series fluctuation.

Then, the waveform file DB5 stored in the database means 3 is input (step S33),
The creation process of the fault plane rupture model ends. On the other hand, when the point source model creation process is performed, the "input point source" displayed in the window W4 is selected to define the point source position (step S34). And the waveform file D
B6 is read out from the database means 3 and input (step S35), and the point source model creation processing ends.

Next, the processing relating to the definition of analysis conditions and the execution of analysis in step S4 is performed. The flow of this processing is shown in FIG. First, the analysis time required for simulation is defined (step S41). Window W
In the example shown in FIG. 5, 20.0 seconds is input as the analysis time. After the input, the output interval of the seismic wave propagation map is defined (step S42). In the example shown in the window W5, 0.5 seconds is input as the interval.

Next, when it is necessary to collect the seismic motion waveform (Y in step S43), the sampling position that requires the seismic motion waveform is defined (step S44). According to the example shown in the window W5, the sampling position is ID1,
It is displayed as ID2 and ID3. Then, in order to analyze the created geological model by the finite element method using a uniform mesh, mesh generation is automatically performed (step S45). When generating this mesh, it corresponds to the input geophysical properties of each region, a uniform mesh is applied to the regions of the same geophysical properties, and the size of the regions of different geophysical properties is different between the multiple regions. Fit a uniform mesh. An example of a mesh-generated geological model is shown in the window W6.

Then, according to the processing flow of the analysis calculation shown in FIG. 2, the analysis by the finite element method is executed (step S46), and the step of the definition of the analysis condition and the analysis execution processing is completed. When the analysis execution process ends, the process proceeds to the result display process of step S5. The flow of this result display processing is shown in FIG.

The flow of the result display processing is divided into the case of displaying the seismic motion waveform and the case of displaying the seismic wave propagation diagram. In the case of seismic motion waveform display, first, the display data of the corresponding waveform is selected based on the result of the analytical calculation (step S
51) Further, after adjusting the waveform display time, the amplitude scale, etc. (step S52), the seismic-motion waveform is displayed for each designated sampling position as in the example shown in the window W7 (step S53). .

In the case of displaying the seismic wave propagation map, first, the contour value scale and the number of colors of the propagation map are adjusted (step S54). Here, the processing flow is divided depending on whether or not the animation of the seismic wave propagation map is displayed (step S
55). When displaying an animation (Y), animation display processing is performed on the seismic wave propagation data,
Animation of seismic wave propagation is displayed in window W8. Then, when the animation file created here is stored (step S57), the animation file is output (step S58), and the step of the result display processing is ended.

In step S55, when the animation is not displayed (N), it is selected at what timing the seismic wave propagation map is displayed in the window W8 (step S5).
9). The seismic wave propagation map designated there is displayed (step S60). If specified again, the specified seismic wave propagation map is displayed. Here, although the display of the seismic wave propagation map ends, if the created image file of the seismic wave propagation map is saved (step S61), the image file is output (step S62), and the step of the result display process ends. To do.

This completes a series of processing operations in the geological wave propagation simulation system. As described above, according to the present embodiment, a geological model is created by inputting boundary conditions of the stratum, and geological physical properties can be associated with each region of the geological model, and when the mesh is generated in the geological model, Corresponding to the entered geophysical properties, apply a uniform mesh for regions with the same geophysical properties, and apply uniform meshes of different sizes for regions with different geophysical properties between multiple regions. By the automatic generation of a uniform mesh by using, a geological wave propagation simulation system that can perform a three-dimensional simulation analysis of a geological model by the finite element method was created.

By adopting the uniform mesh generation for the finite element method analysis, the parameters relating to the mesh shape can be greatly reduced, data compression can be performed, memory consumption can be suppressed, and the operator's input The amount of work can be reduced. Furthermore, by the finite element method analysis using a uniform mesh, 3
The dimensional simulation analysis could be realized and the analysis efficiency could be improved.

For the processing operation, the GUI operation screen is used, and the programs for creating the geological model, defining the geological property values, creating the epicenter model, defining the analysis conditions / executing the analysis, and displaying the results are prepared. It was possible to simplify the simulation process of, reduce the input work, and automate the simulation process.

[0073]

As described above, according to the present invention, the geological wave propagation simulation is specialized in the geological wave propagation analysis, the three-dimensional analysis using the finite element method can be easily performed, and the workload of the operator is reduced. The system can be built,
It is possible to provide a recording medium recording a program that executes the simulation system.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic block configuration of a geological wave propagation simulation system according to the present embodiment.

FIG. 2 is a flowchart showing an analysis process using the uniform mesh finite element method according to the present embodiment.

FIG. 3 is a diagram showing a schematic system flow of a geological wave propagation simulation system according to the present embodiment.

FIG. 4 is a diagram showing an initial screen of GUI operation during analysis.

FIG. 5 is a diagram showing a screen display example when a geological model is created.

FIG. 6 is a diagram showing a screen display example when defining geophysical property values.

FIG. 7 is a diagram showing an example of a screen display when creating a hypocenter model.

FIG. 8 is a diagram showing a screen display example in which a fault plane is represented by a time axis in creating a hypocenter model.

FIG. 9 is a diagram showing an example of a screen display showing a seismic-motion waveform sampling position in a geological model.

FIG. 10 is a diagram showing a screen display example for explaining the automatic generation of a finite element method mesh.

FIG. 11 is a diagram showing a screen display example showing a seismic motion waveform at a designated position as an analysis result.

FIG. 12 is a diagram showing a screen display example in which a seismic wave propagation diagram is displayed as an analysis result.

FIG. 13 is a diagram showing a processing flow of step S1 of FIG.

FIG. 14 is a diagram showing a processing flow of step S2 of FIG.

FIG. 15 is a diagram showing a processing flow of step S3 of FIG.

16 is a diagram showing a processing flow of step S4 of FIG.

17 is a diagram showing a processing flow of step S5 of FIG.

[Explanation of symbols] 1 ... Control means 2 ... storage means 3 ... Database means 4 ... Display means 5 ... Operation means 6 ... Output means 7 ... Transmission / reception means M1-M5 ... Operation menu W1-W8 ... window

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Claims (26)

(57) [Claims] 1. A geological wave propagation simulation system for performing wave propagation analysis of a geological model by the finite element method, comprising: a geological model creating means for creating a geological model to be the target of geological wave propagation ; Geophysical property value defining means for defining the geophysical property value for each region, a hypocenter model creating means for creating a hypocenter model to be input to the geological model, and the region of the geological model in which the geophysical property value is defined A uniform mesh is automatically created, and using this mesh,
A geological wave propagation simulation system comprising: simulation executing means for executing geological wave propagation simulation according to the hypocenter model and analysis conditions; the geological model; and display means for displaying an analysis result by the simulation executing means. 2. The display means has a GUI operation screen, and according to the display of the operation screen, at least the creation of the geological model, the definition of the geological physical property value, the creation of the epicenter model, the definition of the analysis condition, and the simulation. Execution instructions,
The geological wave propagation simulation system according to claim 1, which displays an analysis result. 3. The geological wave propagation simulation system according to claim 1, wherein the simulation executing unit automatically creates a uniform mesh for the fitted regions of the geological model having the same geological property values. 4. The geological wave propagation according to claim 3, wherein the simulation executing unit automatically creates the uniform meshes having different mesh sizes for the fitted regions of the geological model having different geological property values. Simulation system. 5. The geological wave propagation simulation system according to claim 4, wherein the shape of the uniform mesh is a cube. 6. The geological model creating means calculates 3 based on stratum boundary data in a depth direction from a plurality of ground surface positions.
The geological wave propagation simulation system according to claim 1, which automatically creates a three-dimensional geological model. 7. The geological wave propagation simulation system according to claim 6, wherein the geological boundary data is boring data. 8. The geological wave propagation simulation system according to claim 1, wherein the geological model creating means creates a three-dimensional geological model based on the stored geological model data. 9. The geological wave propagation simulation system according to claim 1, wherein the geophysical property value defining means creates a geophysical property value by complementing the seismic velocity gradient in the depth direction with a continuous function. 10. The geological wave propagation simulation system according to claim 1, wherein the hypocenter model creating unit creates the hypocenter model by inputting a fault rupture process. 11. The geological wave propagation simulation system according to claim 10, wherein the seismic source model creating means creates the seismic source model by inputting spatial and temporal distribution behavior with respect to a slip on a fault plane. 12. The hypocenter model creating means creates the hypocenter model by inputting a predetermined earthquake waveform.
The geological wave propagation simulation system described in. 13. The geological wave propagation simulation system according to claim 1, wherein the source model creating means creates a point source model at a designated position in the geological model. 14. The geological wave propagation simulation system according to claim 1, wherein the display means displays a seismic wave waveform at a position designated on the ground surface of the geological model. 15. The geological wave propagation simulation system according to claim 1, wherein the display means displays an animation of a seismic wave propagation map on a designated surface in the geological model. 16. Create a subject to geological model of geologic wave propagation, the geological property values respectively defined for the plurality of areas during the geological model, to create a source model to be input to the geological model, the A uniform mesh is automatically created for the area of the geological model in which the geophysical property values are defined, and using the mesh,
A geological wave propagation simulation is executed according to the hypocenter model and analysis conditions, the geological model and the analysis result by the simulation executing means are displayed, and a program for executing the geological wave propagation simulation of the geological model by finite element method analysis is recorded. Program recording medium. 17. At least creation of the geological model, definition of the geophysical property values, according to display of a GUI operation screen,
The program recording medium according to claim 16, wherein a hypocenter model is created, the analysis condition is defined, a simulation execution instruction is given, and an analysis result is displayed. 18. A mesh size is automatically created for regions of the geological model having the same fitted geophysical property values, and mesh sizes of regions of the fitted geological model having different geophysical property values are automatically generated. The program recording medium according to claim 16, wherein the uniform meshes having different sizes are used. 19. The program recording medium according to claim 16, wherein a three-dimensional geological model is automatically created based on stratum boundary data in the depth direction from a plurality of ground surface positions. 20. The geophysical property value is created by complementing the seismic velocity gradient in the depth direction with a continuous function.
The program recording medium according to 1. 21. The program recording medium according to claim 16, wherein the hypocenter model is created by inputting a fault rupture process. 22. The program recording medium according to claim 21, wherein the seismic source model is created by inputting spatial and temporal distribution behavior with respect to a slip on a fault plane. 23. The program recording medium according to claim 16, wherein the epicenter model is created by inputting a predetermined earthquake waveform. 24. The program recording medium according to claim 16, wherein a point source model is created at a designated position in the geological model. 25. The program recording medium according to claim 16, wherein a seismic motion waveform at a position designated on the ground surface of the geological model is displayed. 26. The seismic wave propagation map on a designated surface in the geological model is displayed as an animation.
The program recording medium according to 1.