JP3358178B2 - Ground liquefaction experimental bottle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground liquefaction test bottle for performing a test of a liquefaction phenomenon in a closed container.

[0002]

2. Description of the Related Art FIG. 3 is a view for explaining the liquefaction phenomenon of the ground, FIG. 4 is a view showing a conventional example of a ground liquefaction experiment apparatus for science education, and FIG. 5 is a figure in which a heavy thing sinks and a light thing rises. It is a figure for explaining an experimental method. In the figure, 11 is a manhole, 12 is a utility pole, 13 is a building, 21, 25, 3
1, 41 are open containers, 22, 26, 34, 42 are sand bodies, 23 is a discharge valve, 24 is a water supply valve, 27 is a stirring rod, 32 is water, 33 is sand, 43 is heavy, and 44 is light. Show things.

[0003] The liquefaction phenomenon of the ground due to an earthquake occurs when, for example, powder such as sand is present in a liquid such as water, and sand and water are integrated into a liquid by a mechanical shock such as an earthquake. It is a phenomenon that behaves. The liquid behavior is a behavior in which the frictional force disappears and the buoyancy of sand water works. As an actual phenomenon, as shown in FIG. 3A, for example, an underground structure such as a manhole 11 floats due to buoyancy of sandy water,
As shown in FIG. 3 (B), an object such as a telephone pole which is protruding above the ground may penetrate into the underground due to the disappearance of the frictional force supporting it, or as shown in FIG. It is a phenomenon that a high thing leans. Heretofore, there have been several methods for easily demonstrating these phenomena.

First, in order to liquefy, sand particles must be in a loose state with many gaps. When liquefaction occurs, the gap is filled and tightened, so that in order to cause liquefaction again, it must be reset to a loose state. Conventional methods for producing sand in a liquefiable state include, for example, the following. Open container 2 containing sand water as shown in FIG.
A loose sand body 22 that can be liquefied by pouring water from the bottom of the container 1 using a water supply 24 or the like and flowing and stirring the sand water in the container is produced. As shown in FIG. 4 (C), by gradually putting sand 33 from above the open container 31 containing water 32,
As shown in (D), a loose sand body 34 that can be liquefied is made. As shown in FIG. 4 (B), an open container 25 containing a sand body.
A loose sand body 26 is made by stirring the sand water with a stirring rod 27. and so on. When the vibration is small, the container is hit, for example, and when the vibration is large, the container is placed on a vibrating table, for example.

In the conventional method of an experiment in which a heavy object sinks and a light object floats, a heavy object 43 is placed on the surface of sand water 42 from an open portion of an open container 41 as shown in FIG. The sand 44 is liquefied by burying the thing 44 in the sand 42 and giving an impact or vibration to the open container 41, so that the heavy thing 43 sinks and the light thing 44 floats as shown in FIG. 5 (B). Like that.

[0006]

However, the conventional methods for demonstrating the above liquefaction phenomenon have the following problems. For example, in the case of a method of forming a loose sand body, in the method shown in FIG. 4 (A) in which water is poured, the liquefiable state can be reset as many times as possible by pouring water, but the apparatus becomes large-scale. Fig. 4 (C), where sand is gradually introduced into the water
In the method shown in (D), sand and water must be completely exchanged in order to repeat the experiment, and the method shown in FIG. There were problems such as the inability to make loose sand bodies. Furthermore, in the conventional method of the experiment in which the heavy object 43 sinks and the light object 44 floats, the experimenter has to set the object directly in the sand water, and it is not easy to repeat the experiment.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a heavy or light object can be placed or buried on the surface of sandy water without putting a hand in a closed container. Liquefaction experiments.

Therefore, the present invention relates to a ground liquefaction test bottle for performing a test of a liquefaction phenomenon in an airtight container, wherein a liquid and powder particles having different specific gravities are deposited below the liquid. A layer is formed and accommodated in a volume, and the liquid and the powder particles are uniformly mixed, and the mixture is heavier and lighter than the sedimentary layer of the powder particles, or the mixture is lighter than the liquid. At least one of the heavy objects is accommodated, and the mixture is formed by swinging the closed container from a state in which the precipitate layer of the powder particles is formed. is there.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing an embodiment of a ground liquefaction experimental bottle according to the present invention, wherein 1 is a closed container, 2 'is an object, 3 is a sand / water mixture, 4 is water,
Numeral 5 indicates a precipitated layer of sand.

In FIG. 1, an airtight container 1 contains an object 2, water 4 and sand whose specific gravities are in a predetermined relationship. The specific gravity relationship between these is that the specific gravity of water 4 is ρ
4. The specific gravity of the sedimentary layer 5 of the sand when precipitated in the water 4 is ρ
5. Assuming that the specific gravity of the sand / water mixture 3 when the water 4 and the sand are made uniform is ρ3, the object 2 is selected such that the specific gravity ρ2 satisfies the relationship of ρ3>ρ2> ρ4. In the ground liquefaction experimental bottles having such a specific gravity relationship, the experiment in which the heavy object 43 shown in FIG. 5 sinks earlier can be performed.

That is, first, as shown in FIG. 1 (A), the sealed container 1 is shaken, and the water 4 and the sand are uniformly mixed to form a sand / water mixture 3. In this state, since the object 2 is lighter than the sand / water mixture 3 and heavier than the water 4, the object 2 sinks together with the upper surface of the sand / water mixture 3 as shown in FIG. And object 2
, Finally land on the surface of the sedimented sand layer 5 which is sinking as shown in FIG. 1C, and the object 2 is stopped and fixed on the sand sediment layer 5. Here, when vibration is applied to the closed vessel 1, the sand 2 is liquefied as shown in FIG. 1D, and the object 2 sinks to a new equilibrium position. Again, as shown in FIG. 1 (A), the closed container 1 is shaken, and the water 4 and the sand are uniformly mixed to form the sand / water mixture 3 so that the closed container 1 is not opened many times. A similar experiment can be repeatedly performed as it is.

In addition, in the ground liquefaction experimental bottle shown in FIG. 2, the specific gravity ρ2 ′ of the object 2 ′ contained in the closed container 1 is ρ5> ρ2 ′> with respect to the object 2 having the specific gravity ρ2 shown in FIG. The one having the relationship of ρ3 is selected. In the ground liquefaction experimental bottle having such a specific gravity relationship, an experiment in which the light object 44 shown in FIG.

In this case as well, first, as shown in FIG. 2A, the closed container 1 is shaken, and the water 4 and the sand are uniformly mixed to form the sand / water mixture 3, whereby the object 2 'is formed. 2 (A) and 2 (B), the sand sinks first, and then the sand sinks to form a sand sediment layer 5 as shown in FIGS.
When the sand is completely settled, the object 2 ′ is completely buried in the sand sediment layer 5, as shown in FIG. Therefore, when vibration is applied to the closed container 1 here, the settled object 2 'rises to a position where buoyancy is balanced by liquefaction of the sand sediment layer 5 as shown in FIG. 2 (D). . Again, as shown in FIG. 2 (A), the closed container 1 is shaken, and the water 4 and the sand are uniformly mixed to form the sand / water mixture 3 so that the closed container 1 is not opened many times. A similar experiment can be repeatedly performed as it is.

Note that the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, in the above-described embodiment, an object 2 lighter than the sand / water mixture 3 or an object 2 ′ heavier than the sand / water mixture 3 is accommodated in the closed container 1, but these objects 2, 2 ′ are accommodated together. You may.
As the object, an object having a shape such as a needle having a large density and a small volume may be used as a weight, and an object having a shape such as a sphere having a small density and a large volume may be used as a float. It may be used in place of water. By doing so, it is possible to make the phenomenon easier to understand by increasing the sink distance.

[0015] Even if there is a loose sandy water layer, it does not liquefy if the thickness of the layer is small. For a simple experiment, the container needs to be small, but the sand water layer is also small and liquefaction is unlikely. In such a case, powder having a smaller particle size than sand, such as glass beads, may be used according to the size of the container. By doing so,
Any number of small scale experiments are possible.

[0016]

As is apparent from the above description, according to the present invention, there is provided a ground liquefaction test bottle for performing a test of a liquefaction phenomenon in a closed container, wherein a liquid and powder particles having different specific gravities are mixed. While accommodating, at least one of an object that is heavier than the mixture when the liquid and the powder particles are uniformly mixed and lighter than the precipitate layer of the powder particles, or lighter than the mixture and heavier than the liquid. After housing, the closed container is rocked to homogenize the powder particles and the liquid, and then the powder particles are settled to form a sedimentation layer. Therefore, it is possible to set a heavy thing which sinks by liquefaction so as not to sink on the surface of the sand water, and a light thing which rises by liquefaction can be set in the sand water. Moreover, it is possible to repeat the liquefaction experiment by placing or filling a heavy or light object on the surface of the sand water without putting a hand in the closed container.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a ground liquefaction experimental bottle according to the present invention.

FIG. 2 is a diagram showing an embodiment of a ground liquefaction experimental bottle according to the present invention.

FIG. 3 is a diagram for explaining the liquefaction phenomenon of the ground.

FIG. 4 is a diagram showing a conventional example of a ground liquefaction experiment device for science education.

FIG. 5 is a diagram for explaining an experimental method in which a heavy object sinks and a light object floats.

[Explanation of symbols]

1: Closed container, 2, 2 ': Object, 3: Sand / water mixture, 4:
Water, 5… sand sediment layer

──────────────────────────────────────────────────の Continuation of the front page (56) References: Jikken 48-38447 (JP, Y1) Kazuyuki Nakagawa, How to Tell the Essence of Natural Disasters to the Next Generation: A Practical Report on Children's Summer School, June 2002 4th, URL, http: // member. ni fitness. ne. jp / n-kaz / t anna / houkoku. htm "Let's Investigate Liquefaction", Children's Science, Seibundo Shinkosha Co., Ltd., August 1, 1998, Vol. 61, No. 8, pp. 44-45. Iruka ", Children's Science Separate Volume Summer Vacation for Elementary School 1-2 Years, Everything Book Nature Observation and Crafts, Seibundo Shinkosha Co., Ltd., July 27, 1979, p. 99 (58) Fields surveyed (Int. Cl. ⁷ , DB name) G09B 23/00-23/40

Claims (1)

(57) [Claims] 1. A ground liquefaction experimental bottle for performing an experiment of a liquefaction phenomenon in a closed container, wherein a liquid and powder particles having different specific gravities are formed with a precipitate layer of the powder particles below the liquid. At least one of an object that is heavier than the mixture when the liquid and the powder particles are uniformly mixed and lighter than the precipitate layer of the powder particles, or an object that is lighter than the mixture and heavier than the liquid. A ground liquefaction experimental bottle, wherein any one of the bottles is accommodated, and the mixture is formed by swinging the closed container from a state in which the precipitate layer of the powder particles is formed.