Simulation equipment, simulation methods, programs
A simulation device simulates soil mixing in a virtual shield tunneling machine, addressing the challenge of varying agitation levels by visualizing and quantitatively evaluating particle distributions to enhance soil mixing and prevent ground collapse.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- MAEDA CORP
- Filing Date
- 2022-06-30
- Publication Date
- 2026-07-07
Smart Images
Figure 0007886206000001 
Figure 0007886206000002 
Figure 0007886206000003
Abstract
Description
Technical Field
[0001] The present invention relates to a simulation device, a simulation method, and a program.
Background Art
[0002] Patent Document 1 discloses a measuring device for the flow of earth and sand in the chamber of an earth pressure balance shield tunneling machine. Patent Document 2 discloses a plastic fluidity evaluation method for creating an analysis model represented by a moving wall with movable stirring blades and evaluating the plastic fluidity of excavated soil.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] Here, the degree of agitation of the earth and sand excavated by the shield tunneling machine varies according to various designs, such as the tunneling speed of the shield tunneling machine, the rotational speed of the stirring blades, and the shape of the stirring blades. In order to properly design the shield tunneling machine, there is a need to simulate the degree of agitation of the earth and sand in advance.
[0005] An object of the present invention is to provide a simulation device, a simulation method, and a program for simulating the degree of agitation of excavated earth and sand.
Means for Solving the Problems
[0006] The invention disclosed in the present application has various aspects to solve the above problems, and the outlines of typical ones of these aspects are as follows.
[0007] (1) A simulation device for simulating the degree of soil mixing by displaying the soil being mixed by the mixing blades of a virtual shield tunneling machine as a group of particles in a virtual three-dimensional space, the simulation device comprising: a generation unit that generates at least a first group of particles, which is a part of the group of particles and to which a first attribute is assigned, and a second group of particles, which is another part of the group of particles and to which a second attribute is assigned, from different positions in the radial direction of the mixing blades, in conjunction with the tunneling operation of the virtual shield tunneling machine; and an acquisition unit that acquires first distribution information relating to the distribution of the first group of particles and second distribution information relating to the distribution of the second group of particles.
[0008] (2)(1) A simulation device having a model generation unit that generates a virtual shield tunneling machine having a chamber that forms a stirring region in which the particle group is stirred by the stirring blade, and the acquisition unit acquires the first distribution information and the second distribution information in at least a part of the stirring region.
[0009] (3)(1) A simulation device comprising a model generation unit that generates a virtual shield tunneling machine comprising a chamber that forms a stirring region in which the particle group is stirred by the stirring blades, and a discharge pipe that discharges the particle group to the outside of the chamber, wherein the acquisition unit acquires the first distribution information and the second distribution information in at least a portion of the region within the discharge pipe.
[0010] (4) A simulation device having an evaluation unit that evaluates the degree of mixing of the soil based on the first distribution information and the second distribution information in any of (1) to (3), wherein the evaluation unit evaluates the degree of mixing based on at least one of the number of particles included in the first particle group and the number of particles included in the second particle group.
[0011] (5) A simulation device having an evaluation unit that evaluates the degree of mixing of the soil based on the first distribution information and the second distribution information in any of (1) to (3), wherein the evaluation unit evaluates the degree of mixing based on the ratio of the number of particles in the second particle group to the number of particles in the first particle group.
[0012] (6) A simulation apparatus having an attribute assignment unit that assigns different attributes to the first particle group and the second particle group, respectively, so that in any of (1) to (5), the first particle group and the second particle group are displayed in a manner that makes them visually distinguishable.
[0013] (7)(6) A simulation device wherein the attribute assignment unit assigns a third attribute to the particle group in such a manner that it can be visually distinguished according to the time the particle group resides in the stirring region where it is stirred by the stirring blade.
[0014] (8) A simulation device having, in any of (1) to (7), a calculation unit that calculates the movement of particles included in the first particle group and the second particle group in the virtual three-dimensional space in conjunction with the excavation operation of the virtual shield tunneling machine, and a display control unit that dynamically displays the three-dimensional movement of particles included in the first particle group and the second particle group based on the calculation results of the calculation unit.
[0015] (9)(8) The display control unit is a simulation device that displays the movement trajectories of the particles included in the first particle group and the second particle group as lines.
[0016] (10) A simulation method for simulating the degree of soil mixing by displaying the soil being mixed by the mixing blades of a virtual shield tunneling machine as a group of particles in a virtual three-dimensional space, the simulation method comprising the steps of: generating at least a first group of particles, which is a part of the group of particles and to which a first attribute is assigned, and a second group of particles, which is another part of the group of particles and to which a second attribute is assigned, from different positions in the radial direction of the mixing blades, in conjunction with the tunneling operation of the virtual shield tunneling machine; and acquiring first distribution information relating to the distribution of the first group of particles and second distribution information relating to the distribution of the second group of particles.
[0017] (11) A program that causes a computer to simulate the degree of soil mixing by displaying the soil being mixed by the mixing blades of a virtual shield tunneling machine as a group of particles in a virtual three-dimensional space, the program causing the computer to perform the following steps in conjunction with the tunneling operation of the virtual shield tunneling machine: a first group of particles which is a part of the group of particles and to which a first attribute is assigned, and a second group of particles which is another part of the group of particles and to which a second attribute is assigned, from different positions in the radial direction of the mixing blades; and a first distribution information relating to the distribution of the first group of particles and a second distribution information relating to the distribution of the second group of particles. [Effects of the Invention]
[0018] According to the present invention, it is possible to provide a simulation device, a simulation method, and a program for simulating the degree of mixing of excavated soil. [Brief explanation of the drawing]
[0019] [Figure 1] This is a schematic front view showing the virtual shield tunneling machine of this embodiment as seen from the front. [Figure 2] This is a cross-sectional view showing the cross-section cut along the line II-II in Figure 1. [Figure 3] This figure shows an example of the hardware configuration of the simulation device according to this embodiment. [Figure 4] It is a block diagram showing an example of the functional configuration of the simulation device according to this embodiment. [Figure 5] It is a schematic diagram schematically showing the movement of the first particle group in the chamber in the virtual three-dimensional space. [Figure 6] It is a schematic diagram schematically showing the movement of the second particle group in the chamber in the virtual three-dimensional space. [Figure 7] It is a diagram showing an example of the distribution of the first particle group and the second particle group in this embodiment. [Figure 8] It is a flowchart showing the processing in the simulation device according to this embodiment. [Figure 9] It is a diagram showing an example of the distribution of the number of particles on a cross-section orthogonal to the direction in which the rotation axis extends. [Figure 10] It is a diagram showing an example of the distribution of the number of particles on a cross-section orthogonal to the direction in which the rotation axis extends.
Mode for Carrying Out the Invention
[0020] Hereinafter, an embodiment according to the present invention (hereinafter referred to as this embodiment) will be described with reference to the drawings.
[0021] [Shield tunneling machine as an actual machine] In this embodiment, a virtual shield tunneling machine 1 obtained by three-dimensionally modeling a so-called earth pressure type shield tunneling machine that converts excavated earth and sand into mud by mixing it with a mud material (additive) and advances while maintaining a uniform force for pressing against the ground will be described. First, before describing the virtual shield tunneling machine 1 displayed in the virtual three-dimensional space, the actual shield tunneling machine will be described.
[0022] A shield tunneling machine is used, for example, when forming a tunnel or a subway. A shield tunneling machine is a machine that excavates the ground in front of its advancing direction, sends the excavated earth and sand to the rear, and assembles a cylindrical wall (segment) so that the ground does not collapse.
[0023] In this case, if the excavated soil is not sufficiently mixed in the shield tunneling machine, sparse areas may occur in the mixed fluid of the sludge material and soil, resulting in uneven pressure on the ground. Uneven pressure on the ground can lead to partial collapse of the ground.
[0024] The degree to which the soil is mixed depends on factors such as the mixing capacity, which is determined by the excavation speed of the shield tunneling machine, the rotation speed of the cutter head and mixing blades, and the shape of the cutter head and mixing blades, as well as the material of the sludge additive, the amount of sludge additive injected, and the injection location of the sludge additive.
[0025] For example, if the excavation speed is high, the work progresses quickly, but the time for mixing the excavated soil is shortened, resulting in insufficient mixing of the soil. Conversely, if the excavation speed is low, the time for mixing the excavated soil is longer, allowing for sufficient mixing of the soil, but the work progresses more slowly.
[0026] While a shield tunneling machine capable of sufficiently agitating soil is desirable, as mentioned above, the degree of agitation is determined by various factors, including the agitation capacity of the shield tunneling machine itself, making it difficult to design the desired machine in advance. Furthermore, if the degree of agitation could be visually confirmed during actual excavation work, future designs could be planned based on the results of the confirmation. However, it is not possible to visually confirm how the soil is being agitated. This is because, in earth pressure balance type shield tunneling machines, the area where the soil is agitated is obstructed by a partition wall.
[0027] Therefore, in this embodiment, a simulation device 100 is provided that simulates the degree of soil mixing by displaying the soil being mixed by the mixing blades 12 as a group of particles, together with a virtual shield tunneling machine 1 having mixing blades 12 in a virtual three-dimensional space.
[0028] [Virtual Shield Tunneling Machine 1] Referring to Figures 1 and 2, the virtual shield tunneling machine 1 displayed in the virtual three-dimensional space in the simulation device 100 according to this embodiment will be described. Figure 1 is a schematic front view showing the virtual shield tunneling machine of this embodiment as seen from the front. Figure 2 is a cross-sectional view showing the cut surface taken along the II-II cutting line in Figure 1. The virtual shield tunneling machine 1 is preferably displayed on the display 105 (see Figure 3), which will be described later.
[0029] In each diagram, arrow X1 indicates the forward direction, arrow X2 indicates the backward direction, arrow Y1 indicates the left direction, arrow Y2 indicates the right direction, arrow Z1 indicates the upward direction, and arrow Z2 indicates the downward direction. The virtual shield tunneling machine 1 travels with the forward direction.
[0030] The virtual shield tunneling machine 1 has a cutter head 11 and a stirring blade 12. The cutter head 11 may be spoke-shaped, for example, as shown in Figure 1. That is, the cutter head 11 may have multiple fan-shaped openings that penetrate in the front-rear direction. With this shape, the soil excavated by the cutter head 11 flows through the openings formed in the cutter head 11 into the stirring region S described later, depending on the excavation speed of the virtual shield tunneling machine 1, and is stirred by the stirring blade 12 in the stirring region S.
[0031] The cutter head 11 constitutes the front part of the shield tunneling machine 1, and cutter bits 11a and 11b, which are cutting blades for excavation, are provided on its front surface. Figures 1 and 2 show the cutter bit 11a provided in the center of the cutter head 11 and multiple cutter bits 11b provided in the radial portions of the cutter head 11. Note that the shape of the cutter head 11 shown in Figure 1, and the arrangement and number of cutter bits 11a and 11b, are examples only and are not limited to these.
[0032] The cutter head 11 rotates in conjunction with the rotation of a rotating shaft 111 that extends in the front-rear direction. A stirring blade 12 is fixed to the rotating shaft 111, and rotates in conjunction with the rotation of the rotating shaft 111. The stirring blade 12 is preferably rod-shaped and extends rearward from the cutter head 11. The stirring blade 12 may be integrally constructed with the cutter head 11. In other words, the stirring blade 12 is part of the cutter head 11, and the cutter head 11 itself may have a stirring function.
[0033] Furthermore, the virtual shield tunneling machine 1 includes a chamber 13 that forms a stirring region S in which the soil excavated by the cutter bits 11a and 11b is stirred by the rotation of the stirring blades 12, a partition wall 14 that separates the stirring region S from the region on the opposite side of the direction of travel, and a discharge pipe 15 that discharges soil from inside the chamber 13.
[0034] Fixed blades 141 are attached to the bulkhead 14. The fixed blades 141 themselves do not rotate, but they contribute to agitation by disrupting the flow of soil and sediment when they hit them as the soil and sediment are shoved up by the rotation of the stirring blades 12.
[0035] The chamber 13 is cylindrical and forms a mixing region S behind the cutter head 11. In the mixing region S, the excavated soil and mud additive are kept in place while the virtual shield tunneling machine 1 is performing its excavation operation. The excavation operation refers to the operation in which the virtual shield tunneling machine 1 moves forward while excavating the ground G.
[0036] The discharge pipe 15 is a pipe that extends rearward from the mixing area S through a through-hole formed in the partition wall 14. The soil mixed in the mixing area S flows into the discharge port formed at the tip of the discharge pipe 15 and moves rearward beyond the partition wall 14. In other words, as soil is excavated in conjunction with the excavation operation of the virtual shield tunneling machine 1, new soil is generated in the mixing area S, and the soil in the mixing area S is successively discharged to the outside through the discharge pipe 15. As described above, since the mixing area S is kept filled with soil and sludge material, approximately the same amount of soil as the newly excavated soil flows into the discharge pipe 15.
[0037] Figures 1 and 2 show a virtual shield tunneling machine 1, which is a three-dimensional representation of only some of the components of an actual shield tunneling machine. However, the virtual shield tunneling machine 1 may be displayed as a more faithful reproduction of the actual machine, or it may be displayed in a more simplified form. For example, the cutter head 11 of the virtual shield tunneling machine 1 does not need to be displayed. Also, for example, the area between the cutter head 11 and the ground G, and the injection pipe for injecting mud filler into the chamber 13 may be displayed. Furthermore, erectors and the like that which grip the segments and set them in predetermined positions may also be displayed.
[0038] [Hardware configuration of simulation device 100] Referring to Figure 3, an overview of the hardware configuration of the simulation device 100 will be described. Figure 3 is a diagram showing an example of the hardware configuration of the simulation device according to this embodiment.
[0039] The simulation device 100 is a computer operated by the user. The simulation device 100 includes a control unit 101, a storage unit 102, a communication unit 103, an operation unit 104, and a display 105.
[0040] The control unit 101 includes at least one processor. The control unit 101 executes processing according to a program stored in the memory unit 102. The memory unit 102 includes a main memory unit and an auxiliary memory unit. For example, the main memory unit is a volatile memory such as RAM, and the auxiliary memory unit is a non-volatile memory such as a hard disk or flash memory. The communication unit 103 includes a communication interface for wired or wireless communication, and for example, performs data communication over a network. The operation unit 104 is an input device, such as a touch panel, a pointing device such as a mouse, or a keyboard. The operation unit 104 transmits the operation content to the control unit 101. The display 105 is, for example, a liquid crystal display or an organic EL display.
[0041] The program described as being stored in the memory unit 102 may be supplied to the simulation device 100 via a network. Furthermore, the hardware configuration of the simulation device 100 is not limited to the above example, and various hardware can be applied. For example, the simulation device 100 may include a reading unit for reading computer-readable information storage media (e.g., an optical disc drive or a memory card slot) and an input / output unit for directly connecting to external devices (e.g., a USB terminal). In this case, the program stored on the information storage media may be supplied to the simulation device 100 via the reading unit or the input / output unit.
[0042] [Functional configuration of simulation device 100] Referring to Figure 4, an overview of the functional configuration of the simulation device 100 will be described. Figure 4 is a block diagram showing an example of the functional configuration of the simulation device according to this embodiment. Note that Figure 4 does not show all the functions of the simulation device 100, and functions with little technical relevance to the present invention have been omitted.
[0043] The simulation device 100 includes a model generation unit 20, a generation unit 30, a calculation unit 40, an attribute assignment unit 50, an acquisition unit 60, an evaluation unit 70, and a display control unit 80. These functions are preferably implemented by a computer executing a program.
[0044] The model generation unit 20 generates a virtual shield tunneling machine 1 to be displayed in a virtual three-dimensional space. The virtual shield tunneling machine 1 generated by the model generation unit 20 is displayed on the display 105 by the display control unit 80.
[0045] The model generation unit 20 should be able to generate virtual shield tunneling machines 1 of various designs in response to user operations on the operation unit 104. For example, the shapes of the cutter head 11 and stirring blades 12, the position of the discharge pipe 15, and the position of the injection pipe displayed in the virtual three-dimensional space should be set in advance as appropriate.
[0046] The generation unit 30 generates a group of particles from the soil agitated by the stirring blades 12 of the virtual shield tunneling machine 1 in conjunction with the excavation operation of the virtual shield tunneling machine 1. The group of particles generated by the generation unit 30 is displayed on the display 105 by the display control unit 80. The model of the particles generated by the generation unit 30 may have a constant or variable kinematic viscosity coefficient.
[0047] The calculation unit 40 calculates the behavior (movement) of each particle in the particle group generated by the generation unit 30. The calculation unit 40 may calculate the three-dimensional movement of each particle in the particle group by calculating the three-dimensional position coordinates of each particle in the particle group that are displaced in conjunction with the excavation operation of the virtual shield tunneling machine 1.
[0048] Here, the behavior of each particle in the particle group is preferably calculated based on, for example, the particle method. The particle method is a technique that discretizes a fluid, which is a continuum, by representing it as a collection of multiple particles, assigns velocity and pressure values to each particle, and modifies the velocity and pressure due to the interaction of the particles with each other. Note that methods other than the particle method may be used to calculate the behavior of the particles. At a minimum, any method that can discretize a fluid, which is a continuum, by representing it as a collection of multiple particles and simulate the movement of the particles is acceptable; for example, the discrete element method may be used. In the particle method and the discrete element method, the Navier-Stokes equations, which are second-order nonlinear partial differential equations that describe the motion of fluids, are used.
[0049] The display control unit 80 may, based on the calculation results from the calculation unit 40, display on the display 105 that each particle in the particle group is displaced in the forward / backward, circumferential, and radial directions in accordance with the excavation operation of the virtual shield tunneling machine 1. That is, each particle in the particle group may be displayed as moving in the circumferential direction as the cutter head 11 and stirring blade 12 rotate, and also as diffusing in the forward / backward and radial directions. By representing the three-dimensional movement of each particle in the particle group in three-dimensional space in this way, the user can visually recognize the movement of soil and sand accompanying the excavation operation of the shield tunneling machine.
[0050] Furthermore, the display control unit 80 may display the movement trajectory of each particle in the particle group as a line. This makes it possible to visualize how the soil mixes inside the chamber 13, which cannot be seen in actual shield construction. In other words, the user can visually recognize the movement of the soil over time.
[0051] The attribute assignment unit 50 assigns attributes to the particle group representing soil and sand. In this embodiment, the attribute assignment unit 50 assigns a first attribute to the first particle group that originates from the inside of the stirring blade 12 in the radial direction, and assigns a second attribute to the second particle group that originates from the outside of the stirring blade 12 in the radial direction, compared to the first particle group.
[0052] In other words, the generation unit 30 generates a first particle group, which is a part of the particle group representing the excavated soil and is assigned a first attribute, and a second particle group, which is another part of the particle group representing the excavated soil and is assigned a second attribute, from different positions in the radial direction, in conjunction with the excavation operation of the virtual shield tunneling machine 1. The display control unit 80 may display the first particle group and the second particle group in a manner that makes them visually distinguishable. For example, each particle of the first particle group may be displayed in blue, and each particle of the second particle group may be displayed in red.
[0053] The acquisition unit 60 acquires first distribution information relating to the distribution of the first particle group and second distribution information relating to the distribution of the second particle group. For example, the acquisition unit 60 may acquire the number and proportion of particles of the first particle group and the second particle group present in a predetermined area after the excavation operation of the virtual shield tunneling machine 1 has been performed for a predetermined time. The acquisition unit 60 may acquire the number and proportion of particles of the first particle group and the second particle group present in the predetermined area multiple times each time a predetermined period of time has elapsed. Alternatively, for example, the acquisition unit 60 may acquire at least one of the total number of particles of the first particle group or the total number of particles of the second particle group that have passed through the predetermined area before the predetermined time has elapsed.
[0054] The predetermined region from which distribution information is acquired by the acquisition unit 60 is, for example, within the stirring region S, and is preferably on a cut surface cut in a direction perpendicular to the direction in which the rotation axis 111 extends.
[0055] Specifically, the acquisition unit 60 may define the area on the AA cross-section and the BB cross-section as predetermined regions, as shown in Figures 5 and 6 described later. That is, the acquisition unit 60 may acquire distribution information on the AA cross-section and the BB cross-section, respectively, after the excavation operation of the virtual shield tunneling machine 1 has been performed for a predetermined time.
[0056] The evaluation unit 70 evaluates the degree of soil mixing based on the first and second distribution information acquired by the acquisition unit 60. For example, the evaluation unit 70 may evaluate the degree of mixing by statistically processing the variation in the number of first and second particle groups in a predetermined area. Alternatively, the evaluation unit 70 may determine whether the design of the virtual shield tunneling machine 1 is appropriate based on the variation in particles. That is, the evaluation unit 70 may determine whether the tunneling speed of the shield tunneling machine, the rotation speed of the mixing blades and cutter head, the shape of the mixing blades and cutter head, the amount of sludge injected, and the injection position of the sludge injected are appropriate based on the variation in particles.
[0057] Furthermore, the predetermined region from which distribution information is acquired by the acquisition unit 60 may be, for example, the cross-section passing through the discharge pipe 15. Specifically, the predetermined region may be the CC cross-section shown in Figures 5 and 6 described later. That is, the acquisition unit 60 may acquire distribution information on the CC cross-section after the excavation operation of the virtual shield tunneling machine 1 has been performed for a predetermined time. The evaluation unit 70 may then evaluate the degree of mixing based, for example, on the ratio of the number of particles in the first particle group and the number of particles in the second particle group that have passed through the discharge port of the discharge pipe 15.
[0058] The predetermined region from which distribution information is acquired by the acquisition unit 60 is not limited to a two-dimensional region such as a cross-section, but may also be a three-dimensional region. That is, the predetermined region may be, for example, the entire agitation region S. In this case, the evaluation unit 70 may evaluate the degree of agitation based on the distribution information of the first particle group and the second particle group present in the entire agitation region S after the excavation operation has been performed for a predetermined time.
[0059] [Example of an evaluation method] Here, an example of a method for evaluating the degree of mixing will be described with reference to Figures 5 to 8. Figure 5 is a schematic diagram illustrating the movement of the first group of particles in the chamber in a virtual three-dimensional space. Figure 6 is a schematic diagram illustrating the movement of the second group of particles in the chamber in a virtual three-dimensional space. Figure 7 is a diagram showing an example of the distribution of the first and second groups of particles in this embodiment.
[0060] In Figure 7, the horizontal axis represents the stirring time, and the vertical axis represents the number of particles that passed through the outlet of the discharge pipe 15 (for example, the cross-section CC shown in Figures 5 and 6). In Figure 7, white circles represent the number of particles in the first particle group, and black circles represent the number of particles in the second particle group. That is, the white circles represent the first distribution information regarding the distribution of the first particle group, and the black circles represent the second distribution information regarding the distribution of the second particle group.
[0061] As shown in Figure 1, both the cutter head 11 and the stirring blade 12 rotate based on the rotation of the rotation axis 111. The peripheral speed is slow on the side of the cutter head 11 closer to the center of rotation, i.e., the radially inner side. On the other hand, the peripheral speed is fast on the side of the cutter head 11 closer to the outer edge, i.e., the radially outer side. The larger the diameter of the cutter head 11 and the stirring blade 12, the more pronounced the difference in peripheral speed between the radially inner and outer sides becomes. Due to this difference in peripheral speed in the radial direction, as well as the shape of the stirring blade 12, the soil excavated at different positions in the radial direction will move differently.
[0062] As shown in Figure 5, each particle in the first particle group, representing soil excavated on the radially inner side, tends to spread radially due to centrifugal force as it moves behind the mixing area S. On the other hand, as shown in Figure 6, each particle in the second particle group, representing soil excavated on the radially outer side, tends to maintain a state of being mixed radially outward in both the forward and backward directions.
[0063] In this embodiment, the outlet of the discharge pipe 15 is positioned at the bottom of the chamber 13. This is because the soil moves in accordance with the rotation of the stirring blade 12, but is also affected by gravity. By positioning the outlet of the discharge pipe 15 downwards, it becomes easier to discharge particles representing the soil in the stirring area S to the outside. In addition, the calculation unit 40 should take the effect of gravity into consideration when calculating the movement of each particle.
[0064] Here, if the number of particles that have passed through the outlet of the discharge pipe 15 after a predetermined time has elapsed is the same for the first particle group and the second particle group, it can be said that the soil and sand are well mixed. When the soil and sand are well mixed, there are few sparse regions in the mixed fluid of the sludge material and soil and sand, and the pressing force against the ground G is uniform.
[0065] Figure 7 shows an example where, with a short stirring time, most of the second particle group passes through the outlet, while most of the first particle group does not. Furthermore, Figure 7 shows an example where, as the stirring time increases, the number of particles in the second particle group passing through the outlet decreases, while the number of particles in the first particle group passing through the outlet increases.
[0066] Furthermore, Figure 7 shows an example where, after a predetermined stirring time T has elapsed, the number of particles in the first particle group passing through the discharge port stabilizes, as does the number of particles in the second particle group passing through the discharge port. In addition, the example shown in Figure 7 shows that after a predetermined time T has elapsed, the ratio of the number of particles in the first particle group to the number of particles in the second particle group is almost constant (see the dashed line in Figure 7).
[0067] As shown in the simulation results in Figure 7, it can be seen that in an actual shield machine, the excavation speed and other parameters should be set so that the stirring time is a predetermined time T.
[0068] Furthermore, the evaluation unit 70 may evaluate the degree of mixing based on the calculated values, for example, by calculating the standard deviation and coefficient of variation of the number of particles in the first particle group within the dashed line in Figure 7. Specifically, the evaluation unit 70 may calculate the standard deviation indicating the degree of variation of the first particle group based on the six pieces of information regarding the number of particles in the first particle group shown within the dashed line in Figure 7. Similarly, the evaluation unit 70 may calculate the standard deviation indicating the degree of variation of the second particle group based on the six pieces of information regarding the number of particles in the second particle group shown within the dashed line in Figure 7. In the example shown in Figure 7, the evaluation unit 70 will evaluate that the second particle group is mixed more evenly than the first particle group.
[0069] Furthermore, the acquisition unit 60 may acquire the ratio of the number of particles in a predetermined area at a predetermined timing two or more times, changing the excavation speed. In this case, the evaluation unit 70 may perform an evaluation based on the ratio of the number of particles (distribution information) acquired two or more times. For example, if the ratio of the number of particles in the second particle group to the number of particles in the first particle group at the excavation speed of the first simulation is 1.5, and the ratio of the number of particles in the second particle group to the number of particles in the first particle group at the excavation speed of the second simulation is 1.1, the evaluation unit 70 may determine that the excavation speed in the second simulation is better mixed. By repeatedly performing simulations with changing conditions in this way, the optimal design can be derived.
[0070] [flowchart] Now, with reference to Figure 8, the processing flow in the simulation apparatus according to this embodiment will be described. Figure 8 is a flowchart of the processing in the simulation apparatus according to this embodiment.
[0071] First, the model generation unit 20 generates a virtual shield tunneling machine 1 (S1). The generated virtual shield tunneling machine 1 is preferably displayed on the display 105 by the display control unit 80. Furthermore, various designs of the generated virtual shield tunneling machine 1 may be pre-set by user operation.
[0072] Next, the display control unit 80 displays the excavation operation of the virtual shield tunneling machine 1 (S2). In response to the excavation operation of the virtual shield tunneling machine 1, the generation unit 30 generates a group of particles to which attributes have been assigned (S3).
[0073] The calculation unit 40 calculates the movement of each particle in the particle group according to the excavation operation, and the display control unit 80 displays the results based on the calculation (S4). Furthermore, the acquisition unit 60 acquires the first distribution information of the first particle group and the second distribution information of the second particle group (S5). Then, the evaluation unit 70 evaluates the degree of mixing based on the first and second distribution information (S6).
[0074] [Other examples of evaluation methods] Next, other examples of methods for evaluating the degree of mixing will be described with reference to Figures 5, 6, and 9. Figure 9 shows an example of the particle number distribution on a cross-section perpendicular to the direction in which the rotation axis extends. Figure 9(a) shows an example of the particle number distribution on the AA cross-section in Figures 5 and 6, and Figure 9(b) shows an example of the particle number distribution on the BB cross-section in Figures 5 and 6. In Figure 9, each white circle represents one particle from the first group of particles excavated radially inward, and each black circle represents one particle from the second group of particles excavated radially outward.
[0075] Figure 9(a) shows that in the front of the stirring region S, the particles of the first particle group are relatively concentrated in the center, while Figure 9(b) shows that in the rear of the stirring region S, the particles of the first particle group and the particles of the second particle group are relatively evenly distributed throughout the mixture.
[0076] The evaluation unit 70 evaluates the degree of mixing based on the distribution information on the AA and BB cross-sections shown in Figures 5 and 6 over a predetermined time. If, over a predetermined time, the excavated soil is evenly distributed both radially inward and outward in any region, the soil can be evaluated as well mixed. For example, the evaluation unit 70 can evaluate that the soil is well mixed if the number of particles in the first particle group and the number of particles in the second particle group are equal in both the central region 1 shown in Figures 9(a) and 9(b), and in the entire mixing region S, which is region 2. In the example shown in Figures 9(a) and 9(b), since the first particles are densely concentrated in the center of the AA cross-section, the evaluation unit 70 evaluates that the excavated soil is well mixed as it moves backward, but not well mixed while it is in the forward position.
[0077] Furthermore, other examples of methods for evaluating the degree of mixing will be explained with reference to Figure 10. Figure 10 shows an example of the particle number distribution on a cross-section perpendicular to the direction in which the rotation axis extends. Both Figure 10(a) and Figure 10(b) show examples of the particle number distribution on the BB cross-section of Figures 5 and 6. Figure 10(a) is the result of the first simulation, and Figure 10(b) is the result of the second simulation, in which the drilling speed and other factors were changed from the first simulation.
[0078] Figure 10(a) shows an example where the first and second particles are present in similar proportions in regions 1 and 2. Figure 10(b) shows an example where the proportion of first particles to second particles is high in region 1. For example, if soil enters the mixing region S in a clump and mixing is not sufficiently performed in the mixing region S, an imbalance in the particle ratio tends to occur, as shown in Figure 10(b). Based on these results, the evaluation unit 70 determines that the first simulation result shown in Figure 10(a) is more preferable than the second simulation result shown in Figure 10(b).
[0079] [summary] By using the simulation device 100 according to this embodiment described above, the movement of soil and sediment from excavation to discharge from the outlet of the discharge pipe 15 can be simulated and evaluated with high reproducibility, which can be useful for the appropriate design of the shield tunneling machine. Furthermore, the simulation device 100 according to this embodiment can visualize and qualitatively represent the diffusion of excavated soil and sediment, and can quantitatively evaluate the degree of mixing based on the number and proportion of particles.
[0080] Furthermore, the attributes assigned to a group of particles are not limited to two types. For example, a group of particles representing soil excavated at three or more different locations in the radial direction may be displayed with a different color for each. In this case, the degree of mixing can be evaluated based on the distribution of each of the particle groups representing soil excavated at three or more different locations in the radial direction.
[0081] Furthermore, the evaluation of the simulation results is not limited to that performed by the evaluation unit 70 of the simulation device 100; it may also be subjectively evaluated by the user by visually observing the degree of particle mixing visualized and displayed in a virtual three-dimensional space. In other words, it is not essential for the simulation device 100 to have an evaluation unit 70.
[0082] Furthermore, for example, particles that remain in the agitation area S for a long period of time may be assigned a new attribute related to long-term retention. Specifically, for example, the attribute assignment unit 50 may assign an attribute related to long-term retention to particles that remain in the agitation area S without being discharged from the discharge pipe 15 even after 1 hour has elapsed since the start of the excavation operation. Particles assigned the attribute related to long-term retention may be displayed in a color other than red and blue by the display control unit 80. This makes it possible to identify areas in the shield tunneling machine where the flow tends to stagnate, such as corners. Alternatively, the evaluation unit 70 may detect areas where particles are stagnating based on the density of particles in a predetermined area within the shield tunneling machine 1. In this case, for example, the density of the first and second particles in that predetermined area may be obtained, and it may be evaluated whether the excavated soil is more likely to stagnate at the radially inner or outer position.
[0083] Furthermore, the virtual shield tunneling machine 1 only needs to move relative to the virtual ground G. That is, in a real shield tunneling machine, the machine moves forward, but in the virtual shield tunneling machine 1 of this embodiment, the virtual shield tunneling machine 1 may be displayed as fixed, and the ground G side may be displayed as moving backward. [Explanation of Symbols]
[0084] 1 Virtual shield tunneling machine, 11 Cutter head, 11a, 11b Cutter bits, 111 Rotating shaft, 12 Agitator blade, 13 Chamber, 14 Partition wall, 15 Discharge pipe, 20 Model generation unit, 30 Generation unit, 40 Calculation unit, 50 Attribute assignment unit, 60 Acquisition unit, 70 Evaluation unit, 100 Simulation device, 101 Control unit, 102 Storage unit, 103 Communication unit, 104 Operation unit, 105 Display, S Agitation area.
Claims
1. A simulation device that simulates the degree of soil mixing by displaying the soil being mixed by the mixing blades of a virtual shield tunneling machine as a group of particles in a virtual three-dimensional space, A generating unit generates, in conjunction with the drilling operation of the virtual shield tunneling machine, at least a first group of particles which is part of the particle group and is located on the radially inner side of the stirring blade in the initial stage of generation, and a second group of particles which is another part of the particle group and is located on the radially outer side of the stirring blade beyond the inner side in the initial stage of generation, An attribute assignment unit assigns a first attribute to the first particle group and a second attribute to the second particle group so that the first particle group and the second particle group are displayed in a manner that makes them visually distinguishable; An acquisition unit that acquires first distribution information relating to the distribution of the first particle group from the initial stage of generation to a predetermined time after a predetermined time has elapsed, and second distribution information relating to the distribution of the second particle group. A simulation device having the following features.
2. The model generation unit generates a virtual shield tunneling machine which has a chamber that forms a stirring region in which the particle group is stirred by the stirring blades, The acquisition unit acquires the first distribution information and the second distribution information in at least a portion of the stirring region. The simulation apparatus according to claim 1.
3. The model generation unit generates a virtual shield tunneling machine comprising a chamber that forms an agitation region in which the particle group is agitated by the agitation blades, and a discharge pipe that discharges the particle group to the outside of the chamber. The acquisition unit acquires the first distribution information and the second distribution information in at least a portion of the area within the discharge pipe. The simulation apparatus according to claim 1.
4. It has an evaluation unit that evaluates the degree of soil mixing based on the first distribution information and the second distribution information, The evaluation unit evaluates the degree of stirring based on at least one of the number of particles in the first particle group and the number of particles in the second particle group. A simulation apparatus according to any one of claims 1 to 3.
5. It has an evaluation unit that evaluates the degree of soil mixing based on the first distribution information and the second distribution information, The evaluation unit evaluates the degree of stirring based on the ratio of the number of particles in the second particle group to the number of particles in the first particle group. A simulation apparatus according to any one of claims 1 to 3.
6. The attribute assignment unit assigns a third attribute to the particle group in such a manner that it can be visually distinguished according to the time the particle group resides in the stirring region where it is stirred by the stirring blade. A simulation apparatus according to any one of claims 1 to 3.
7. A calculation unit that calculates the movement of particles included in the first particle group and the second particle group in the virtual three-dimensional space in conjunction with the excavation operation of the virtual shield tunneling machine, A display control unit that dynamically displays the three-dimensional movement of particles included in the first particle group and the second particle group based on the calculation results of the calculation unit, A simulation apparatus according to any one of claims 1 to 3.
8. The display control unit displays the movement trajectories of the particles included in the first particle group and the second particle group as lines. The simulation apparatus according to claim 7.
9. A simulation method for simulating the degree of soil mixing by displaying the soil being mixed by the mixing blades of a virtual shield tunneling machine as a group of particles in a virtual three-dimensional space, The steps include generating, in conjunction with the drilling operation of the virtual shield tunneling machine, at least a first group of particles which is part of the particle group and is located on the radially inner side of the stirring blade at the initial stage of generation, and a second group of particles which is another part of the particle group and is located on the radially outer side of the stirring blade at the initial stage of generation, The steps include assigning a first attribute to the first particle group and a second attribute to the second particle group so that the first particle group and the second particle group are displayed in a manner that makes them visually distinguishable, The steps include obtaining first distribution information regarding the distribution of the first group of particles from the initial stage of generation to a predetermined time after a predetermined period of time has elapsed, and second distribution information regarding the distribution of the second group of particles, A simulation method having the following characteristics.
10. A program that causes a computer to simulate the degree of soil mixing by displaying the soil being mixed by the mixing blades of a virtual shield tunneling machine as a group of particles in a virtual three-dimensional space, A procedure for generating, in conjunction with the drilling operation of the virtual shield tunneling machine, at least a first group of particles which is part of the particle group and is located on the radially inner side of the stirring blade at the initial stage of generation, and a second group of particles which is part of the particle group and is located on the radially outer side of the stirring blade at the initial stage of generation, A procedure for assigning a first attribute to the first particle group and a second attribute to the second particle group so that the first particle group and the second particle group are displayed in a manner that makes them visually distinguishable, A procedure for obtaining first distribution information relating to the distribution of the first group of particles from the initial stage of generation to a predetermined time after the elapsed time, and second distribution information relating to the distribution of the second group of particles. A program that causes a computer to execute something.