Granular material spread-out device and ground model manufacturing method

Abstract

To provide a granular material spread-out device that allows efficient manufacture of a ground model having a uniform relative density, and a ground model manufacturing method using the granular material spread-out device.SOLUTION: A granular material spread-out device 1 is used in accumulating granular material S constituting a ground model inside a soil tank 2, and comprises: a hopper 3 that is arranged at a position higher than the soil tank 2; a transport hose 4 that is extended from a lower part of the hopper 3; and an end cap 5 that is provided at a leading end of the transport hose 4. The end cap 5 exhibits a truncated cone shape in which the inner diameter of a leading end part 52 is larger than the inner diameter of a base end part 51 connected to the transport hose 4. The leading end of the end cap 5 is shielded by a bottom plate 54 that is formed with a plurality of through holes 53 through which the granular material S can pass. The inside of the end cap 5 is partitioned by partition walls so as to spread the granular material S to the plurality of through holes 53.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a granular material spreading device used for producing a ground model and a ground model production method.

Background Art

[0002] In order to understand the behavior of the ground during an earthquake, a centrifugal loading experiment may be conducted. The centrifugal loading experiment reproduces the same stress field as the actual object by applying an acceleration N times the gravitational acceleration to a ground model in a shear soil tank scaled down to 1 / N times the actual size. When producing a ground model, it is necessary to make the initial relative density of the ground uniform. As a method for producing a ground model, there is an air-drop method in which a hose with a funnel attached to its tip is moved while keeping the height of the funnel's discharge port constant to uniformly spread sand. However, when using this method, it is time-consuming and inefficient when the soil tank is large.

[0003] Patent Document 1 discloses a sand dropping device for reducing the labor required for producing a ground model, which includes a hopper disposed on a rail and a grooved feeder disposed in the hopper. In the sand dropping device of Patent Document 1, the hopper storing sand moves on the rail, the sand in the hopper enters the groove of the feeder, and the sand in the groove drops due to the rotation of the feeder, so that the sand can be dropped (spread) evenly in the length direction of the feeder.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The sand dropping device of Patent Document 1 deposits sand in the soil tank by dropping sand from above the soil tank. Therefore, when placing a structure model on the ground model, it is not possible to directly drop sand directly below the structure model. For this reason, there was a possibility that the density of the ground would not be uniform between directly below the structure model and around the structure model. Further, since the sand dropping device of Patent Document 1 drops sand from a hopper that moves on a rail laid on the soil tank, the height at which the sand is dropped (the height from the upper surface of the ground model to the supply body) changes as the work progresses. Therefore, there was a possibility that the density of the ground model would change in the depth direction.

[0006] An object of the present invention is to provide a granular material spreading device capable of efficiently producing a ground model with a uniform relative density and a ground model production method using this granular material spreading device.

Means for Solving the Problems

[0007] In order to solve the above problems, the present invention is a granular material spreading device used when depositing granular materials constituting a ground model in a soil tank, and includes a hopper disposed at a position higher than the soil tank, a transport hose extending from the lower part of the hopper, and an end cap provided at the tip of the transport hose. The end cap has a frustoconical shape in which the inner diameter of the tip portion is larger than the inner diameter of the base end portion connected to the transport hose, and the tip of the end cap is shielded by a bottom plate in which a plurality of through holes through which the granular material can pass are formed, and the inside of the end cap is partitioned so that the granular material reaches the plurality of through holes.

[0008] Further, in the ground model production method using the granular material spreading device, the granular material flowing down from the hopper through the transport hose is spread on the soil tank while moving the end cap, so that the granular material is deposited uniformly.

[0009] According to such a granular material scattering device and a ground model manufacturing method, since the inner diameter of the end cap is enlarged toward the tip (lower end), the granular material can be scattered over a wide range. Therefore, compared with the conventional sand scattering method using a funnel, a ground model can be manufactured efficiently. Further, since the height position of the end cap can be set at a predetermined position, a homogeneous ground model can be manufactured by the air-drop method. Furthermore, since the position and orientation of the end cap can be freely changed, even when a structure model is arranged on the ground model, the granular material can be scattered below the structure model.

[0010] In addition, a plurality of flow paths from the base end portion to the through holes may be formed in the end cap, or the inside may be divided in the radial direction by a plurality of concentric frustum-shaped partition walls, or the inside may be divided in the circumferential direction by a partition wall erected on the bottom plate. By doing so, since the granular material reaches all of the plurality of through holes, the granular material can be scattered over a wider range more reliably.

Advantages of the Invention

[0011] According to the granular material scattering device and the ground model manufacturing method of the present invention, it becomes possible to efficiently manufacture a ground model having a uniform relative density.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0013] In this embodiment, the case of fabricating a ground model in a centrifugal loading experiment will be described. The ground model is fabricated by depositing granular materials (e.g., sand, gravel, beads, etc.) S in a soil tank 2. In this embodiment, when fabricating the ground model, a granular material spreading device 1 is used. The granular material spreading device 1 is shown in FIG. 1. As shown in FIG. 1, the granular material spreading device 1 includes a hopper 3, a transport hose 4, and an end cap 5.

[0014] The hopper 3 is disposed at a position higher than the soil tank 2 by being provided on a gantry 6 formed by a scaffold or the like. The hopper 3 has a size capable of storing an amount of granular material S necessary for forming the ground model. A discharge port for the granular material S is formed at the lower end of the hopper 3. A transport hose 4 is attached to the discharge port. Note that the configuration of the gantry 6 is not limited, and it is not necessarily formed by a scaffold.

[0015] The transport hose 4 extends from the lower part of the hopper 3 to the soil tank 2. The transport hose 4 guides the granular material S discharged from the discharge port to the soil tank 2. The granular material S in the hopper 3 is discharged from the discharge port by natural fall and supplied to the soil tank 2 via the transport hose 4. An end cap 5 is provided at the tip (lower end) of the transport hose 4.

[0016] The end cap 5 is configured such that the base end portion 51 is connected to the lower end of the transport hose 4, and the granular material S transported by the transport hose 4 can be discharged from the tip end portion 52. As shown in FIGS. 2(a) to (c), the end cap 5 has a frustum shape, and the inner diameter of the tip end portion 52 is larger than the inner diameter of the base end portion 51. Further, the tip end (lower end) of the end cap 5 is shielded by a bottom plate 54 in which a plurality of through holes 53 through which the granular material S can pass are formed. Inside the end cap 5, a plurality of flow paths 55 extending from the base end portion 51 to the through holes 53 are formed. That is, the inside of the end cap 5 is partitioned such that the granular material S reaches the plurality of through holes 53, 53,.... In the present embodiment, the flow path 55 is constituted by a tube connected to each through hole 53. Note that the flow path 55 is not limited to a tube, and for example, a tubular body or a gutter-shaped member may be provided.

[0017] Next, when producing a ground model using the granular material spreading device 1, the granular material S that has flowed down naturally from the hopper 3 via the transport hose 4 is spread over the soil tank 2. The granular material S that has flowed down through the transport hose 4 is discharged from the through holes 53 of the end cap 5. At this time, by moving the end cap 5, the granular material S is spread so as to be deposited uniformly.

[0018] According to the method for producing a ground model using the granular material spreading device 1 of the present embodiment, since the inner diameter of the end cap 5 increases toward the tip end (lower end), the granular material S can be spread over a wide range. Therefore, compared with the conventional method of spreading sand using a funnel, a ground model can be produced efficiently.

[0019] Further, since the height position of the end cap 5 can be arranged at a predetermined position, a homogeneous ground model can be produced by the air-drop method. Furthermore, since the position and orientation of the end cap 5 can be freely changed, even when a structure model is arranged on the ground model, the granular material S can be spread below the structure model.

[0020] In addition, since a plurality of flow paths 55 extending from the base end portion 51 to the through holes 53 are formed inside the end cap 5, the granular material S can reach all of the plurality of through holes 53, 53,... evenly. Therefore, the granular material S can be spread more reliably over a wider range compared to the conventional method of spreading using a funnel. As a result, the granular material S can be spread to have a uniform layer thickness, and thus a model ground with a uniform relative density can be produced. Note that if only the number of discharge ports of the end cap 5 is increased, the granular material S will only flow to the central portion of the end cap 5, so the granular material S cannot be spread evenly. On the other hand, in the end cap 5 of the present embodiment, the granular material S can be spread evenly by causing the granular material S to reach all the through holes 53 through the flow paths 55.

[0021] In the conventional spreading method, it may be considered to increase the diameter of the transport hose 4 to increase the spreading amount. However, if the diameter of the transport hose 4 is increased, the weight of the transport hose 4 increases and it becomes difficult to bend, so it becomes difficult to handle. On the other hand, according to the granular material spreading device 1 of the present embodiment, the granular material S can be spread over a wider range than before without increasing the diameter of the transport hose 4, so it is efficient.

[0022] Further, according to the granular material spreading device 1 of the present embodiment, even when performing an experiment in which a structure is provided on the model ground, the granular material S can be spread evenly and in a short time even directly under the structure or at the end of the soil tank 2. Therefore, it is possible to reduce the labor of the work.

[0023] The granular material spreading device 1 has a relatively simple configuration, so the manufacturing cost is low. In addition, since the cleaning after use is completed only by cleaning the transport hose 4 and the end cap 5, the time for tidying up can be shortened. In addition, since it does not require the operation of special machinery or the like, anyone can produce a high-quality model ground without requiring special skills.

[0024] As described above, the embodiments of the present invention have been explained. However, the present invention is not limited to the above-described embodiments, and each of the above-described components can be appropriately changed without departing from the spirit of the present invention. For example, in the above embodiment, the case where the inside of the end cap 5 is divided by the flow path 55 has been described. However, the configuration of the end cap 5 is not limited to this. FIGS. 3 and 4 show other forms of the end cap 5.

[0025] As shown in FIG. 3(b), the inside of the end cap 5 may be divided in the radial direction by a plurality of frustum-shaped (tapered) partition walls (radial partition walls 56, 56,...). The plurality of radial partition walls 56 are concentrically arranged. The granular material S flowing in from the base end portion 51 of the end cap 5 spreads from the center portion to the edge portion of the bottom plate by the radial partition walls 56. Further, as shown in FIG. 3(a), it is desirable that the end cap 5 is further divided by a second partition wall (circumferential partition wall 57) arranged radially in addition to the radial partition wall 56. By doing so, the granular material S can be more surely spread over each through hole 53.

[0026] Also, as shown in FIGS. 4(a) and (b), the end cap 5 may be divided in the circumferential direction by a circumferential partition wall 57 erected on the bottom plate. The granular material S flowing in from the base end portion 51 of the end cap 5 is guided to the regions divided by the circumferential partition wall 57, so that the granular material S is discharged from all the through holes 53. The circumferential partition wall 57 is arranged so that the granular material S is evenly spread over the entire bottom plate 54 (all the through holes 53).

Explanation of Reference Numerals

[0027] 1 Granular material spreading device 2 Soil tank 3 Hopper 4 Transport hose 5 End cap 51 Base end portion 52 Tip end portion 53 Through hole 54 Bottom plate 55 Flow path 56 Radial partition wall (partition wall) 57 Circumferential partition wall (partition wall) 6 Stand S Granular body

Claims

1. A granular material spreading device used when depositing granular materials that make up a ground model in a soil tank, a hopper disposed at a position higher than the soil tank, a transport hose extending from the lower part of the hopper, and an end cap provided at the tip of the transport hose, and the end cap has a frustum shape with an inner diameter at the tip larger than the inner diameter at the base end connected to the transport hose, the tip of the end cap is shielded by a bottom plate in which a plurality of through holes through which the granular material can pass are formed, the granular material spreading device, characterized in that the inside of the end cap is partitioned so that the granular material reaches all of the plurality of through holes.

2. The granular material spreading device according to claim 1, characterized in that a plurality of flow paths from the base end portion to the through holes are formed inside the end cap.

3. The granular material spreading device according to claim 1, characterized in that the inside of the end cap is partitioned in the radial direction by a plurality of frustum-shaped partition walls.

4. The granular material spreading device according to claim 1, characterized in that the inside of the end cap is partitioned in the circumferential direction by a partition wall erected on the bottom plate.

5. A method for producing a ground model using the granular material spreading device according to any one of claims 1 to 4, characterized in that the granular material flowing down from the hopper through the transport hose is spread on the soil tank while moving the end cap, thereby depositing the granular material uniformly.

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