JP7574038B2 - Ground surface treatment method and ground surface treatment structure - Google Patents

Description

The present invention relates to a method for treating the surface of ground and a structure for treating the surface of ground.

The present applicants have developed techniques such as those described in Patent Documents 1 and 2 as a surface treatment method for ground to reinforce weak clayey soil. Planar members are laid on the ground, bags are arranged in a lattice on the planar members, and a fluid solidification material such as mortar is filled inside the bags and solidified to form a lattice-shaped rigid reinforcement. This surface treatment method allows the rigidity of the rigid reinforcement to distribute the load of the covering soil, and the soft ground can be made into a ground with sufficient bearing capacity that is less likely to settle unevenly. In addition, the presence of the planar members prevents the clayey soil from mixing with the covering soil (earth and sand or crushed stone), making it easy to carry out work to return the ground to its state before the ground reinforcement.

In Patent Document 1, a comb-shaped bag (surface treatment bag) is composed of a base end bag and two or more rows of branch side bags arranged in a direction perpendicular to the base end bag. A set of these comb-shaped surface treatment bags is prepared, and multiple rows of branch side bags constituting one surface treatment bag are stacked on top of multiple rows of branch side bags constituting the other surface treatment bag so that both branch side bags form a lattice. A fluid solidification material is then filled from the base end bag to the branch side bag, and a lattice-shaped rigid reinforcement is formed as the fluid solidification material solidifies.

According to the method described in Patent Document 1, by using a comb-shaped bag body (a bag body for surface treatment), the fluid solidification material can be filled inside the bag body without excessively increasing the injection pressure of the fluid solidification material into the bag body, thereby improving the work efficiency of ground surface treatment work.

In Patent Document 2, a temperature control member made of a tube member that circulates a heat medium is installed together with the bag body. By running hot or cold water through this temperature control member, the solidification temperature of the fluid solidification material filled inside the bag body can be adjusted, shortening the construction period and ensuring the quality of the rigid reinforcement body.

JP 2006-348481 A JP 2012-31596 A

Conventional surface treatment methods such as those described in Patent Documents 1 and 2 have left the following problems to be solved:

When the inside of the bag is filled with a fluid solidification material such as mortar, the internal pressure applied at that time causes the bag to expand and contract. Conventionally, the bags are laid either in a lattice pattern, with multiple horizontal rows of bags stacked on top of multiple vertical rows of bags, or in a lattice pattern, with multiple vertical rows of bags stacked on top of multiple horizontal rows of bags. As shown in FIG. 1 of Patent Document 2, the upper bag filled with the fluid solidification material has a mountain shape that overcomes the lower bag filled with the fluid solidification material at the lattice points, so the upper bag is made to a length that takes this amount (excess length) into account.

For example, when treating the surface of ground with an area of 100m x 100m, the internal pressure caused by filling with the fluid solidification material causes the bag to stretch, and the excess length at the end of the bag becomes excessive, causing the bag to protrude from the installation area. In this case, it is necessary to treat the protruding part of the bag, but cutting the protruding part is not desirable because cutting will cause the fluid solidification material to flow out. In addition, it is not easy to fold the protruding part of the bag and fix the bag in the folded state.

In addition, the internal pressure caused by filling with the fluid solidification material varies, making it difficult to accurately estimate the excess length, and the length of the bag may actually be insufficient. If the bag length is insufficient, it will not be possible to form a lattice-shaped rigid reinforcement over the entire installation range, and the strength of the ends of the installation range may decrease.

As described above, the conventional surface treatment methods described in Patent Documents 1 and 2 have the problem that it is difficult to control the length of the bag body.

As described above, the conventional laying of the bags is either a lattice pattern in which multiple horizontal rows of bags are stacked on top of multiple vertical rows of bags, or a lattice pattern in which multiple vertical rows of bags are stacked on top of multiple horizontal rows of bags. That is, multiple rows of bags extending in one direction are stacked on top of multiple rows of bags extending in another direction to form a lattice pattern. According to this stacking method, the lower bag is held down from above by the upper bag filled with a fluid solidification material, but since there is nothing on the upper bag, its movement is not particularly restricted before it is covered with soil or crushed stone. Therefore, the upper bag may shift due to the soil or crushed stone that falls when the soil is covered, causing the lattice points to shift. If the lattice points shift, the uniformity of the rigidity of the rigid reinforcement body is lost, which may have an adverse effect on the bearing capacity of the ground. Patent Document 1 states that the bags may be connected at the lattice points, etc., by belts or the like. However, with this method, the belt length takes into account the expansion of the bag body, and it is difficult to ensure that the upper and lower bags are firmly connected at the lattice points after the fluid solidification material is filled.

The present invention was made in consideration of the above circumstances, and its purpose is to provide a ground surface treatment method and ground surface treatment structure that makes it easy to manage the length of the bag body and that is less likely to cause the lattice points of the bag body to shift.

The present invention is a ground surface treatment method comprising a bag laying step of laying a plurality of bags filled with a fluid solidification material in a lattice pattern on the ground, and a solidification material filling and solidification step of filling the insides of the bags laid in a lattice pattern with a fluid solidification material and solidifying it, characterized in that the bags comprise a first bag extending in a first direction and a second bag extending in a second direction intersecting the first direction, and in the bag laying step, the first bag and the second bag are laid in a lattice pattern in which they overlap and intersect, as if they are woven together in both the first and second directions.

The ground surface treatment method of the present invention has the following effects:

At the lattice points where the bags overlap, the bag portion located on the lower side does not become a mountain shape like the upper bag portion even when filled with the fluid solidification material, so there is no need to expect as much excess length as the upper bag portion at the lattice points. When the bags are laid in a lattice shape by weaving them together as in the present invention, the second bag extending in the second direction is located above the first bag extending in the first direction at the lattice points where the bags overlap, or the second bag extending in the second direction is located below the first bag extending in the first direction. Therefore, according to the present invention, it is not necessary to expect a long excess length of the bag body (second bag body) which has a large uncertainty factor (= difficult to predict accurately) compared to the conventional bag body arrangement in which the second bag body extending in the second direction is always located above the first bag body extending in the first direction at the lattice points lined up in the first direction. As a result, the bag body (second bag body) can be made shorter than before, making it easier for construction workers to manage the length of the bag body.

In addition, with regard to the lattice points where the bags overlap, if a second bag extending in the second direction is positioned above a first bag extending in the first direction, or if a second bag extending in the second direction is positioned below a first bag extending in the first direction, the bag will be pressed from above by the other bag at some lattice points in both the first and second directions, making the bag less likely to shift. If the bag is less likely to shift, the restraining effect is enhanced, as the lattice points are also less likely to shift.

In the present invention, in the bag laying step, it is preferable to lay the first bag body and the second bag body in a lattice pattern so that the overlapping order of the first bag body and the second bag body is alternately reversed in both the first direction and the second direction.

This configuration improves the restraining effect, making it easier to manage the length of the bag body and preventing the lattice points of the bag body from shifting.

In the present invention, it is also preferable that in the bag laying step, the first bag and the second bag are laid in a lattice pattern so that the stacking order is alternately reversed for each bag.

This configuration further enhances the restraining effect, making it harder for the lattice points of the bag to shift.

In the present invention, it is also preferable that in the bag laying step, the bag is laid in a lattice pattern on a planar member laid on the ground.

With this configuration, the planar member can prevent the soil of the ground from mixing with the covering soil, etc., making it easier to carry out work to return the ground to the state it was in before surface treatment.

The present invention also relates to a ground surface treatment structure. The ground surface treatment structure of the present invention comprises a lattice-shaped rigid reinforcement body consisting of a plurality of bags laid on the ground in a lattice pattern and a fluid solidification material filled and solidified inside the bags, and the bags comprise a first bag body extending in a first direction and a second bag body extending in a second direction intersecting the first direction, and are laid in a lattice pattern in which the first bag body and the second bag body overlap and intersect with each other as if they are woven in both the first direction and the second direction.

With this configuration, the surface treatment structure has a restraining effect that makes it easier to manage the length of the bag body and makes it difficult for the lattice points of the bag body to shift, just like the ground surface treatment method of the present invention.

In the surface treatment structure of the present invention, it is preferable that the first bag body and the second bag body are laid in a lattice pattern so that the overlapping order of the first bag body and the second bag body is alternately reversed in both the first direction and the second direction.

This configuration improves the restraining effect, making it easier to manage the length of the bag body and preventing the lattice points of the bag body from shifting.

In addition, in the surface treatment structure of the present invention, it is preferable that the first bag body and the second bag body are laid in a lattice pattern so that the overlapping order is alternately reversed upside down for each bag body.

This configuration further enhances the restraining effect, making it harder for the lattice points of the bag to shift.

In addition, it is preferable that the surface treatment structure of the present invention further includes a planar member laid under the bag body.

With this configuration, the planar member can prevent the soil of the ground from mixing with the covering soil, etc., making it easier to carry out work to return the ground to the state it was in before surface treatment.

It is also preferable that the surface treatment structure of the present invention further comprises a crushed stone layer laid on top of the rigid reinforcement body formed in a grid pattern.

With this configuration, a surface treatment layer is formed in which the crushed stone layer is integrated with a rigid reinforcement body formed in a lattice shape made of the bag body filled with a fluid solidification material, and the restraining effect of the rigid reinforcement body in the lattice shape provides a higher compaction effect than when crushed stone is used alone.

The present invention provides a ground surface treatment method and ground surface treatment structure that makes it easy to manage the length of the bag body and is less likely to cause the lattice points of the bag body to shift.

FIG. 1 is a plan view showing a ground surface treatment structure according to a first embodiment of the present invention. FIG. 5 is a plan view showing a ground surface treatment structure according to a second embodiment of the present invention. FIG. 11 is a plan view showing a ground surface treatment structure according to a third embodiment of the present invention. FIG. 13 is a plan view showing a ground surface treatment structure according to a fourth embodiment of the present invention. 2 is a photograph showing an example of a surface treatment structure for the ground shown in FIG. 1. FIG. 1 is a plan view showing a conventional ground surface treatment structure.

The following describes the embodiment of the present invention with reference to the drawings.

The ground surface treatment structure 101 according to the first embodiment of the present invention will be described with reference to Figures 1 and 5.

The surface treatment structure 101 comprises a planar member 1 laid on the ground and a bag body 2 laid in a lattice pattern on the planar member 1. The bag body 2 is laid in a lattice pattern on the ground via the planar member 1.

The planar member 1 is a sheet member for preventing the soil of the ground from mixing with the covering soil, and is made of, for example, a synthetic fiber woven fabric. The thickness of the planar member 1 is, for example, 0.38 mm, and the tensile strength is, for example, 70 kN/m. The planar member 1 also has the function of dispersing the load of the covering soil together with the lattice-shaped rigid reinforcement body described below. Since the load can be dispersed by the lattice-shaped rigid reinforcement body alone, the planar member 1 may be omitted in cases where the soil of the ground and the covering soil may mix. In other words, the bag body 2 may be laid in a lattice pattern directly on the ground.

The bag body 2 is filled with a fluid solidification material such as mortar, and is called a jacket. When the filled fluid solidification material solidifies, a lattice-shaped rigid reinforcement body is formed. The rigidity of this rigid reinforcement body makes it possible to distribute the load of the covering soil, and it is possible to create a ground with sufficient bearing capacity that is less likely to settle unevenly. The bag body 2 is made of, for example, a tubular woven fabric made of synthetic fibers. The diameter of the bag body 2 is, for example, 100 mm, and the tensile strength is, for example, 130 kN/m. The surface treatment structure 101 includes the bag body 2 laid in a lattice on the ground, and the above-mentioned lattice-shaped rigid reinforcement body made of the fluid solidification material filled and solidified inside the bag body 2.

The bag body 2 comprises a first bag body 3 extending in a first direction X and a second bag body 4 extending in a second direction Y intersecting the first direction X. In this embodiment, the second direction Y (second bag body 4) is perpendicular to the first direction X (first bag body 3), but there are cases where the first direction X (first bag body 3) and the second direction Y (second bag body 4) are not exactly perpendicular to each other.

The grid formed by the multiple first bags 3 and the multiple second bags 4 has a square shape, and the grid spacing is 1m x 1m, 1.5m x 1.5m, 2m x 2m, etc.

As shown in FIG. 1, in this embodiment, in order to further enhance the integrity of the lattice-shaped rigid reinforcement body formed by filling and solidifying a fluid solidifying material such as mortar inside the bag body 2, the first bag body 3 and the second bag body 4 are laid in a lattice shape as if they are woven together so that the overlapping order of the first bag body 3 and the second bag body 4 is alternately reversed upside down for each bag body in both the first direction X and the second direction Y at the lattice point P where the first bag body 3 in the first direction X and the second bag body 4 in the second direction Y overlap and intersect.

As shown in FIG. 5, in order to efficiently fill the insides of the multiple first bags 3 with the fluid solidification material, in this embodiment, the ends of the multiple first bags 3 are connected to the side of the base-end bag 5, and the fluid solidification material is filled from the base-end bag 5 into the multiple first bags 3. Similarly, in order to efficiently fill the insides of the multiple second bags 4 with the fluid solidification material, the ends of the multiple second bags 4 are connected to the side of another base-end bag 6, and the fluid solidification material is filled from the base-end bag 6 into the multiple second bags 4.

The base end bag body 5 and the base end bag body 6 are connected to each other, and a supply port fitting 10 for supplying a fluid solidifying material such as mortar is attached to the end of the base end bag body 6.

Next, an example of a method for treating the ground surface using the planar member 1 and the bag body 2 will be described. Note that the following explanation will be given using an example in which a rice field is temporarily turned into a road (temporary road).

(Bag laying process)
The rice field is excavated, and the excavated ground is shaped and compacted. Then, the planar member 1 is laid on the compacted ground. After that, as shown in Fig. 1, the first bag body 3 and the second bag body 4 are laid on the planar member 1 in a lattice pattern in which the first bag body 3 and the second bag body 4 overlap and cross each other, so that the overlapping order of the first bag body 3 and the second bag body 4 is reversed up and down for each bag body in both the first direction X and the second direction Y, as if they are woven. The base end side bag body 5 and the base end side bag body 6 (see Fig. 5), which are omitted in Fig. 1, are also laid on the planar member 1.

(Solidifying material filling and solidifying process)
Next, mortar (fluid solidification material) is filled into the bag bodies 2 laid in a lattice pattern and solidified. Mortar is supplied from the supply port fitting 10 into the inside of the base end bag body 6. The mortar is filled from the base end bag 6 into the plurality of second bags 4, and is also filled from the base end bag 5 into the plurality of first bags 3. When the mortar filled inside the first bag 3, the second bag 4, the base end bag 5, and the base end bag 6 hardens, a lattice-shaped rigid structure is formed on the planar member 1. A reinforcement is formed.

(Soil covering process)
When the lattice-shaped rigid reinforcement body consisting of the bag body 2 filled with mortar and solidified is formed, crushed stone is poured on the rigid reinforcement body and the planar member 1 and spread evenly to obtain a predetermined finished thickness. Then, the crushed stone is compacted by a rolling machine. Next, the heated asphalt mixture is spread evenly and compacted. In this case, the surface treatment structure 101 of this embodiment further includes a crushed stone layer laid on the lattice-shaped rigid reinforcement body.

After going through the above process, the temporary road will be completed.

When returning the temporary road to its original state, the asphalt and the surface treatment structure 101 (crushed stone (crushed stone layer), the bag body 2 (= lattice-shaped rigid reinforcement body) with mortar filled and solidified inside, and the planar member 1) containing crushed stone (crushed stone layer) are removed. The planar member 1 separates the rice field soil from the crushed stone, making it easy to remove the crushed stone.

Figure 2 is a plan view showing a ground surface treatment structure 102 according to the second embodiment of the present invention. The differences between the second embodiment and the first embodiment are as follows. Note that in the surface treatment structure 102 of the second embodiment, the same reference numerals are used for components that are similar to the components constituting the surface treatment structure 101 of the first embodiment (the same applies to the other embodiments described below).

In the surface treatment structure 101 of the first embodiment, the shape of the grid formed by the multiple first bags 3 and the multiple second bags 4 is a square. In contrast, in the surface treatment structure 102 of the second embodiment, the shape of the grid formed by the multiple first bags 3 and the multiple second bags 4 is a rectangle. The grid spacing is 1 m x 1.5 m, 1 m x 2 m, etc.

Figure 3 is a plan view showing a ground surface treatment structure 103 according to the third embodiment of the present invention. The differences between the third embodiment and the first embodiment are as follows:

In the surface treatment structure 101 of the first embodiment, the first bag body 3 and the second bag body 4 are laid in a lattice pattern so that the overlapping order of the first bag body 3 and the second bag body 4 is alternately reversed upside down for every two bags in both the first direction X and the second direction Y at the lattice point P where the first bag body 3 in the first direction X and the second bag body 4 in the second direction Y overlap and intersect. In contrast, in the surface treatment structure 103 of the third embodiment, the first bag body 3 and the second bag body 4 are laid in a lattice pattern so that the overlapping order of the first bag body 3 and the second bag body 4 is alternately reversed upside down for every two bags in both the first direction X and the second direction Y at the lattice point P where the first bag body 3 in the first direction X and the second bag body 4 in the second direction Y overlap and intersect.

The first bag body 3 and the second bag body 4 may be laid in a lattice pattern so that the stacking order of the first bag body 3 and the second bag body 4 is alternately reversed upside down every three bags, every four bags, etc.

Figure 4 is a plan view showing a ground surface treatment structure 104 according to the fourth embodiment of the present invention. The differences between the fourth embodiment and the first embodiment are as follows:

In the surface treatment structure 104 of the fourth embodiment, at the lattice point P at the upper left of the figure among the multiple lattice points P, the second bag body 4 is superimposed on the first bag body 3. At the lattice point P one lattice point (right) next to this lattice point P in the first direction X and the lattice point P two lattice points (right), the first bag body 3 is superimposed on the second bag body 4. At the lattice point P three lattice points (right) next to this lattice point P in the first direction X, the second bag body 4 is superimposed on the first bag body 3. Similarly, at the lattice point P one lattice point (down) next to the lattice point P at the upper left of the figure in the second direction Y and the lattice point P two lattice points (down), the first bag body 3 is superimposed on the second bag body 4. At the lattice point P three lattice points (down) next to this lattice point P in the second direction Y, the second bag body 4 is superimposed on the first bag body 3.

In this way, the first bag body 3 and the second bag body 4 may be laid in a lattice pattern by weaving the first bag body 3 and the second bag body 4 together. Although not shown, when laying the first bag body 3 and the second bag body 4 in a lattice pattern by weaving the first bag body 3 and the second bag body 4 together, the order of overlapping the first bag body 3 and the second bag body 4 at the lattice point P is not limited to that shown in Figures 1 to 4, and there are various orders.

Figure 6 is a plan view showing a conventional ground surface treatment structure 50.

In the conventional surface treatment structure 50, at lattice points P aligned in the first direction X, a second bag body 4 extending in the second direction Y is always stacked on top of a first bag body 3 extending in the first direction X.

At the lattice point P where the first bag body 3 and the second bag body 4 overlap, the bag body portion located on the lower side does not become a mountain shape like the upper bag body portion even if filled with a fluid solidification material such as mortar (see FIG. 5), so there is no need to expect an excess length like the upper bag body portion at the lattice point P. When the bag body 2 is laid in a lattice shape by weaving the first bag body 3 and the second bag body 4 as in the embodiment shown in FIGS. 1 to 4, with respect to the lattice point P where the bags overlap, the second bag body 4 extending in the second direction Y is located above the first bag body 3 extending in the first direction X, or the second bag body 4 extending in the second direction Y is located below the first bag body 3 extending in the first direction X. Therefore, according to this embodiment, for example, in the lattice points P arranged in the first direction X, the second bag body 4 extending in the second direction Y is always located above the first bag body 3 extending in the first direction X, compared to the conventional surface treatment structure 50 shown in FIG. 6, in which there are many uncertainties (= difficult to estimate accurately), there is no need to estimate the excess length of the bag body (second bag body 4) long. As a result, the bag body (second bag body 4) can be made shorter than before, making it easier for contractors to manage the length of the bag body during on-site construction.

In addition, with regard to the lattice points P where the bags overlap, if a second bag body 4 extending in the second direction Y is positioned above a first bag body 3 extending in the first direction X, or if a second bag body 4 extending in the second direction Y is positioned below a first bag body 3 extending in the first direction X, the bag body 2 (first bag body 3, second bag body 4) in either the first direction X or the second direction Y will be pressed from above by the other bag body at some lattice points P, making the bag body 2 (first bag body 3, second bag body 4) less likely to shift. If the bags are less likely to shift, the lattice points P are also less likely to shift.

In addition, when the bag body 2 (first bag body 3, second bag body 4) is pressed from above at some lattice points P in either the first direction X or the second direction Y, the lattice-shaped rigid reinforcement body formed by filling it with a fluid solidification material such as mortar becomes more integrated than before and is less likely to bend. Note that in the conventional surface treatment structure 50 shown in Figure 6, the second bag body 4 is simply placed on top of the first bag body 3, so it lacks integration.

As in the embodiment shown in Figures 1 to 3, when the first bag body 3 and the second bag body 4 are laid in a lattice pattern so that the overlapping order of the first bag body 3 and the second bag body 4 is alternately reversed upside down in both the first direction X and the second direction Y, the effects of easier management of the bag body length and less misalignment of the lattice point P of the bag body are further enhanced.

As in the embodiment shown in Figures 1 and 2, if the first bag body 3 and the second bag body 4 are laid in a lattice pattern so that the stacking order of the first bag body 3 and the second bag body 4 is alternately reversed upside down for each bag body, the effect of preventing the lattice points P of the bags from shifting is further enhanced. In addition, the integrity of the lattice-shaped rigid reinforcement body formed by filling it with a fluid solidification material such as mortar is further improved, making it less likely to bend.

The above embodiment can be modified as follows:

Instead of providing base end bags 5 and 6 as shown in FIG. 5 and filling the fluid solidification material from the base end bag 5 into the first bags 3 or filling the fluid solidification material from the base end bag 6 into the second bags 4, the fluid solidification material may be filled into the first bags 3 and the second bags 4 one by one.

The above describes an embodiment of the present invention. Of course, various other modifications are possible within the scope of what a person skilled in the art can imagine.

1: Planar member 2: Bag body 3: First bag body 4: Second bag body 101 to 104: Surface treatment structure P: Lattice point X: First direction Y: Second direction

Claims (7)

a bag laying process for laying a plurality of bags filled with the fluid solidification material in a lattice pattern on the ground;
a solidification material filling and solidification process for filling the inside of the bag body laid in a lattice pattern with a fluid solidification material and solidifying it;
A method for treating a surface layer of ground comprising:
The bag body includes a first bag body extending in a first direction and a second bag body extending in a second direction intersecting the first direction,
In the bag laying process, the first bag body and the second bag body are woven so that the overlapping order of the first bag body and the second bag body is alternately reversed upside down in both the first direction and the second direction, and the first bag body and the second bag body are laid in a grid pattern in which they overlap and cross. The method for treating a surface layer of ground according to claim 1 ,
In the bag laying step, the first bag body and the second bag body are laid in a lattice pattern so that the overlapping order is alternately inverted upside down for each bag body. The method for treating the ground surface according to claim 1 or 2 ,
In the bag laying step, the bag is laid in a lattice pattern on a planar member laid on the ground, in the ground surface treatment method. A ground surface treatment structure comprising a lattice-shaped rigid reinforcement body consisting of a plurality of bags laid in a lattice pattern on the ground and a fluid solidification material filled and solidified inside the bags,
The bag body includes a first bag body extending in a first direction and a second bag body extending in a second direction intersecting the first direction,
The bag body is laid in a grid pattern in which the first bag body and the second bag body are overlapped and crossed by weaving the first bag body and the second bag body so that the overlapping order of the first bag body and the second bag body is alternately reversed in both the first direction and the second direction. In the ground surface treatment structure according to claim 4 ,
The ground surface treatment structure is configured such that the first bag body and the second bag body are laid in a lattice pattern so that the overlapping order is alternately inverted upside down for each bag body. In the ground surface treatment structure according to claim 4 or 5 ,
The ground surface treatment structure further comprises a planar member laid under the bag body. In the ground surface treatment structure according to any one of claims 4 to 6 ,
The ground surface treatment structure further comprises a crushed stone layer laid on the rigid reinforcement body formed in a lattice shape.

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