JP4066340B2 - Ground improvement method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ground improvement method for improving a ground under the surface of the water such as a seabed.
[0002]
[Prior art]
For example, underwater ground such as the seabed may be soft and require ground improvement. For ground improvement, it is common to use a dedicated work boat, but if work using the work boat is not possible due to some restrictions, a work facility will be installed on the surface of the water. Work and construction management on an unstable scaffolding.
However, when the ground below the water surface is soft, the support leg portion (leg) of the work facility may not be sufficiently supported.
In addition, if a large amount of fluid substances (so-called “slime”) is generated during ground improvement, the environment is adversely affected.
[0003]
In order to deal with such a problem, Japanese Patent Application No. 2002-200788 proposes a technique that firmly supports the leg of the work facility.
Alternatively, Japanese Patent Application No. 2002-200793 proposes a technique for collecting a large amount of fluid substances (for example, slime) generated during ground improvement without spreading.
These techniques are all useful. Here, in Japanese Patent Application No. 2002-200808 and Japanese Patent Application No. 2002-200793, a large amount of generated fluid substances (for example, slime) are all moved to an industrial waste treatment facility provided separately and processed. ing.
[0004]
However, in recent years, with increasing awareness of environmental problems, there is an increasing demand for effective use of the fluid substance (for example, slime) without processing it at an industrial waste treatment facility.
However, the technology that can respond to this request locally has not been established at present.
[0005]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above-mentioned problems of the prior art, and is performed on a stable scaffold without being affected by weather conditions, tide level, wave force, etc., when improving the ground of soft ground below the surface of the water. The purpose of this project is to provide a ground improvement method that can effectively use fluid substances generated in large quantities during ground improvement.
[0006]
[Means for Solving the Problems]
The ground improvement method of the present invention includes a container-like structure (both having a surface corresponding to the bottom and a case having no surface. For example, caisson 1, a ship, a frame, etc.) Installed on the ground (G) at the bottom of the river, etc., and installed the ground improvement equipment (4, 5) on the container-like structure (1). A ground improvement device or a ground improvement device previously installed on a container-like building and installed at a predetermined position), and the ground improvement device. (4, 5) is used for boring in the vertical direction to the lower area of the container-like structure (1) of the ground (G) below the surface of the water, and the solid material injection means (7) from the ground improvement equipment (4, 5) ) (Perform boring in the vertical direction and insert solidification material injection means into the boring hole. Or the solidification material injection means is inserted while excavating by high pressure jet injection), and the solidification material is injected in the horizontal direction while rotating the solidification material injection means (7). And a solidifying material injecting step for improving the ground by lifting the solidifying material injecting means (7) upward, and the soil and the solidifying material in the ground (G) below the water surface generated during the solidifying material injecting step are mixed. Emissions (including fluid substances such as so-called slime and solids such as solidified slime) discharged from the bottom of the seabed (sea, lake, river, etc.) are contained in the container-like structure (1). It is characterized by being accommodated (claim 1).
[0007]
According to the present invention having such a configuration, the generated slime (S) can be reused as filling (D) in the container-like building (1).
The container-like structure (1) filled with slime can be used as it is as a revetment or an artificial island.
[0008]
Here, there is no problem if the ground (G) below the water surface is hard enough to support the container-like structure (1), but it is soft to the extent that it is difficult to support the structure (1). Can be.
In such a case, prior to installing the container-like structure (1) on the ground (G) below the water surface, the surface layer (F) of the ground (G) below the water surface is improved ( T) is preferable (claim 2).
Thus, by improving the ground surface (T) of only the surface layer portion of the ground (G) below the water surface, the container-like structure (1) can be sufficiently supported by the improved surface layer portion (F). I can do it.
[0009]
In this case, after the surface improvement (T) of the ground surface (G) under the water surface is improved (T), before the container-like structure (1) is installed on the ground surface (G) under the water surface, ( It is preferable to perform a leveling (20F) step of flattening the surface layer portion (F) whose ground has been improved (T) using the leveling crushed stone 20 or the like (Claim 3).
[0010]
In the present invention, the place-through is carried out through the discharged substance (for example, slime S) accommodated in the container-like building (1) and the ground improvement region (8) below the container-like building (1). It is also convenient to provide a foundation (for example, a foundation on which various piles such as cast-in-place piles, steel pipe piles, and hollow piles 74 can be constructed) (Claim 4).
[0011]
With such a configuration, the ground-improved region (8) below the container-like building (1) and the discharge (D: a mixture of solidified materials) contained in the container-like building (1). And solidifying after storage), and further, by utilizing the shear strength of the cast-in-place foundation provided therethrough, it is possible to obtain resistance against horizontal external force.
The improved region (8) configured as described above is suitable for a foundation structure (for example, revetment or bridge) on a soft seabed ground or a site where waves are strong and shear force acts strongly.
When used as a bridge, a footing (88) is placed on top of the container-like structure (1) so that the load of the bridge is uniformly applied to a cast-in-place foundation (eg, piles 76, 85). It is preferable.
In addition, it can be applied to offshore wind power generation facilities, reaching shafts or starting shafts of the shield method.
[0012]
Here, when it becomes a shaft for shielding, it replaces with the said cast-in-place foundation (for example, the piles 76 and 85), the caisson (10) is discharged | emitted in the said container-shaped building (1) (S ) And the container-like building (1) and the ground-improved region (8) below are preferably embedded.
That is, in the present invention, the second through the discharge (S) housed in the container-like building (1) and the ground-improved region (8) below the container-like building (1). It is preferable to embed a container-like structure (for example, a large caisson 10).
[0013]
If comprised in this way, it will become possible to comprise a reaching shaft and a starting shaft using a caisson (10).
[0014]
In the implementation of the present invention, the discharge (for example, slime S) in which the soil of the ground (G) below the water surface and the solidified material generated in the solidified material injection step is mixed is accommodated in the container-like structure (1). When the space in the container-like building (1) is filled with the discharge (S), the container-like building (1) provided with ground improvement devices (4, 5) is installed. ), Another container-like building (1B) is arranged, and the waste (S) mixed with soil and solidification material in the ground (G) under the surface of the water in the other container-like building (1B) ) Is preferably accommodated (claim 6).
[0015]
In this way, in addition to the base container-like building (1), another container-like building (1B) is arranged, and the ground (G) below the water surface also in the other container-like building (1B). In order to accommodate the discharge (S) in which the soil and the solidified material are mixed, even when the discharge amount is large, for example, it is not necessary to carry out processing such as carrying out and dumping to other places on the ground. .
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The first embodiment will be described with reference to FIGS.
[0017]
In FIG. 1, a caisson 1 assembled at a production base (not shown) is towed in a sea area 2 by a tow ship 3 toward a construction site. In the figure, the symbol WL represents the sea surface.
[0018]
As shown in FIG. 2, a part of the upper surface of the caisson 1 is divided into 8 rows by partition walls 1b that divide the inside of the outer peripheral portion 1a surrounding the four surrounding surfaces, in the illustrated example, in the longitudinal direction (left and right direction on the paper surface). A plurality of rows of compartments C are provided by partition walls 1c that partition the width direction (the vertical direction in FIG. 2).
In addition, all the side views of FIGS. 1-18 except FIG. 2 have shown in the state which saw through a part of outer peripheral part 1a.
[0019]
Referring to FIG. 1 again, a top plate 1e is stretched on the top of the caisson 1, and a reinforcing horizontal member 1f is stretched below the top plate 1e. The top plate 1e and the horizontal member 1f are connected by an inclined beam 1g, and are reinforced so that, for example, a crawler crane 4 which is a construction machine for ground improvement described later can be installed on the top plate 1e.
As shown in FIG. 2, the top plate 1e is provided with a portion C partitioned into each room or inside the walls of the partition walls 1b and 1c (not shown) and at the intersections 1b and 1c (shown A). A first working hole 1k is provided for inserting a machine, for example, a boring rod (not shown).
[0020]
A bottom member 1 m is stretched on the bottom of the caisson 1. A second work hole (casing pipe) 1n (see FIG. 2) is provided at a position facing the first work hole (guide pipe) 1k provided in the top plate 1e of the bottom member 1m. However, the second work hole 1n is closed by a lid (not shown) in order to avoid submergence of the caisson 1 during towing.
[0021]
Further, a skirt 1s extends below the bottom member 1m to extend the outer peripheral portion 1a and the partition walls 1b and 1c for the purpose of mitigating the influence of tidal currents and transverse waves by penetrating into the seabed ground G described later. Is formed.
[0022]
When the tow ship 3 reaches the sea area 2 above the ground G on the seabed at the construction site, for example, at the standing position of the pier, the sea water is poured into several sections in the caisson 1 and the caisson 1 is set.
In addition, in order to balance at the time of installation, the amount of water injection is adjusted for each section.
[0023]
On the seabed B at the construction site, the skirt 1s penetrates the ground G due to the weight of the caisson 1 itself.
[0024]
A boring rod 6 (described later) or a construction machine 4 equipped with a high-pressure jet injector (for example, “super jet”) and a boring support device 5 such as a compressor or a generator on the top plate 1e of the caisson 1 thus installed. Install.
[0025]
In FIG. 4, the boring rod 6 of the construction machine 4 is inserted into the first and second work holes 1k and 1n formed in the top plate 1e and the bottom member 1m of the caisson 1, and as shown in FIG. The ground G in the construction area directly under the caisson 1 is excavated to drill the borehole Hb.
[0026]
After the boring hole Hb is drilled, the attachment at the tip of the boring rod 6 is replaced with a monitor 7 which is a solidifying material injection means as shown in FIG. Alternatively, the high pressure jet injector is used as it is.
The monitor 7 or the high-pressure jet injector is rotatable about a vertical axis, and is configured to inject a jet J of a high-pressure solidified material in the horizontal direction.
Therefore, when the monitor 7 or the high-pressure jet injector is rotated (R arrow) and pulled upward (Y arrow), the ground G in the construction area is excavated by the force of the jet J, and the mixture of soil and solidified material generated by the excavation is obtained. The so-called “slime S” is generated.
[0027]
The soil firmly bonded with the solidified material improves the soil in the construction area immediately below the caisson 1 on the seabed. In FIG. 4, reference numeral 8 indicates an improved region.
In addition, the fluid slime S is sucked into the slime processing device 9 installed on the top plate 1e of the caisson 1 by, for example, a suction hose (not shown), and the slime S needs to increase in weight in the slime processing machine 9. In this case, after adding sand and, if necessary, solidifying material and kneading, the material is put into the room C partitioned by the partition wall of the caisson 1, the bottom member 1m, and the auxiliary member 1f by the discharge hose 91.
[0028]
Here, some compartments contain water, but some compartments are empty. Fill the empty compartment with slime.
Once the slime is filled and the required weight is obtained, the initially filled water is drained and emptied.
[0029]
In order to store the slime in the water-filled compartment (substitute with water), add a thickener or non-separation agent in the slime and put the water in the caisson in the manner of placing the concrete underwater. Can also be substituted.
[0030]
In this way, when each section C of the caisson 1 is sequentially filled with a mixture of sand or solidified material (the section in the filled state is labeled with D), it will eventually harden and become an artificial island, revetment, pier, etc. The base of is completed.
[0031]
In the first embodiment using the above-described configuration and construction method, the generated slime S can be reused as a filling of the caisson 1.
The caisson 1 filled with the slime S can be used as it is as a revetment or an artificial island.
[0032]
Next, a second embodiment will be described with reference to FIGS.
[0033]
In the first embodiment shown in FIGS. 1 to 6, the surface layer portion of the seabed B in the construction region is not very soft and can be supported even if the caisson 1 is installed on the surface layer portion as it is.
On the other hand, in the second embodiment shown in FIGS. 7 to 11, when the surface layer portion of the construction area is very soft and the caisson cannot be installed and supported as it is, the surface layer portion is strengthened and improved in advance. It is a form. It is also effective as a method for more strictly managing the slime leakage.
[0034]
In FIG. 7, since the surface layer portion F of the ground G including the region to be constructed is soft, a depth of, for example, 5 m from the sea floor B of the surface layer portion is strengthened / improved by a known method before the caisson 1 is installed. The symbol T in the figure indicates an improved area.
[0035]
On the surface layer of the improved region T, embankment or crushed stone 20 is laid and crushed and leveled by the thrust bar 3d of the submarine construction ship 3D. That is, leveling crushed stone (leveling process) is performed. Reference numeral 20F in the figure indicates a leveled area.
[0036]
In FIG. 8, the caisson 1 is towed by the tow ship 3 to the upper surface of the improvement area T of the construction area to above the area 20F leveled by the above-mentioned embankment or crushed stone 20.
[0037]
FIG. 9 shows a state in which the caisson 1 is installed on the above-described leveled area 20F.
[0038]
In FIG. 10, when a plurality of caissons 1 are required, a tow vessel 3 tows a second caisson 1 </ b> A different from the first caisson (first caisson) 1 to the vicinity of the first caisson 1.
When the second caisson 1A approaches the first caisson 1, the caissons are once connected by the mooring rope 30, and the rope 30 is moved by the winch 35 on the first caisson side, and the second of the tow ship 3 The caisson 1A is pushed, and the second caisson 1A is brought into contact with the first caisson 1.
[0039]
FIG. 11 is a view showing a construction mode for improving the construction area of the seabed ground G after contacting the two caissons 1 and 1A. The concrete construction contents are the same as those in the first embodiment. This is the same as the construction contents described in FIGS.
Instead of adding caisson, abandoned ships may be sunk. Further, any container-like structure may be used as long as it has a strength capable of withstanding water pressure and a volume capable of filling the generated slime.
[0040]
In this way, the caisson 1 can be reliably and firmly supported after the surface improvement F of the surface layer F requiring ground improvement in advance under the water surface.
[0041]
Next, with reference to FIGS. 12-16, the method of the large diameter cast-in-place construction which is 3rd Embodiment is demonstrated.
[0042]
In FIG. 12, the caisson 1 is in a state filled with a slime and / or a mixture D of slime and solidified material, sand, etc. accommodated in the compartment C of the caisson 1 according to the first embodiment of FIGS.
On the other hand, a construction machine (crawler crane) 4 and an all-round rotary excavator 46 are installed on the top plate 1 e of the caisson 1.
[0043]
Then, a large-diameter excavation bit 44 provided at the tip of the casing 42 is operated by an all-round rotary excavator 46 on the top plate 1 e and is discharged by a hammer grab 40 provided on the crawler crane 4. By these means, the large-diameter excavation hole H2 has a section C in the caisson filled with slime and / or a mixture D such as slime and a solidified material or sand, and an improved region 8 directly below the caisson. The ground G below the region 8 that has further improved the ground is drilled until reaching a predetermined depth.
[0044]
FIG. 13 shows an excavation drilled through the section C filled with the slime and / or the mixture D of slime and solidified material, sand, etc. in the caisson 1 and the ground improved region 8 immediately below the caisson. A state in which a double-structured cylindrical reinforcing bar 70 is suspended inside the hole H2 by the crane ship 3A is shown.
On the top plate 1e, a reinforcing bar temporary fixing device 72 for temporarily fixing a double-structured reinforcing bar rod 70 before placing concrete, which will be described later, is installed. A hollow member 74 is formed inside the reinforcing bar 70.
[0045]
FIG. 14 shows ready-mixed concrete from a concrete pump ship 3B which is formed by a drill hole H2 and the outer periphery of the hollow member 74 and floats on the sea (sea surface, water surface) WL in a region including the reinforcing bar 70 via a concrete hose P. A state in which is placed is shown.
In addition, the outer peripheral part of the hollow member 74 is comprised with the cylindrical body 75 made from steel, for example so that the ready-mixed concrete cast from the said outer peripheral part may not flow in the inside of the hollow member 74.
A hollow concrete column 76 is formed by placing ready-mixed concrete in an area including the rebar rod 70 formed with the excavation hole H2.
In addition, although the process so far (FIGS. 12-14) demonstrated that it constructs in the state which filled the slime or its mixture D in the division C of the caisson 1 as shown in FIG. Then, after the concrete column 76 is formed, the gap between the concrete column 76 and the section may be filled with slime or a mixture D thereof (or residual soil 82 described later).
Here, in order to use the frictional force between the high-pressure jet injection part and the pile of the solidified caisson part to effectively use the support force against the horizontal external force, the cast-in-place large-diameter pile may be used. desirable.
[0046]
FIG. 15 shows a state in which the excavation residual soil 82 generated during the above-mentioned drilling stored in the hopper 80 is backfilled in the hollow member 74 using the crane 4 and a new excavation hole H2 is excavated. FIG.
In addition, when the excavation residual soil 82 generated at the time of drilling cannot be accommodated in the hollow member and the caisson, it is carried out by the earth and sand transport ship 3C anchored at the sea WL.
[0047]
In FIG. 16, in the illustrated cross section, excavation holes H2 are formed in four sections of the caisson 1, and as described with reference to FIGS. 14 and 15, the hollow member 74 is filled with excavation residual soil 82 and the like. The filling (85) is tamped by known means.
[0048]
Ready concrete from the complete pump ship 3B anchored at sea is filled into the remaining space other than the slime and excavated soil filled section D, the hollow concrete pillar 76, and the filler 85 in the caisson 1. Is done. Further, for example, a footing 88 is constructed so that the load of the bridge is uniformly applied to the pile.
[0049]
As described above, since the cast-in-place foundation is provided through the fluid substance contained in the caisson 1, for example, the slime and the ground improved region 8 below the previous caisson 1, the ground improvement below the caisson 1 is improved. Utilizing the frictional force between the area 8 and the slime contained in the caisson 1 (because it is a mixture of solidified materials, it solidifies after storage. The solidified material may be stored), and against the external force in the horizontal direction. Support force can be obtained.
The improved region 8 configured as described above is suitable for a foundation structure (for example, a seawall or a bridge) on a soft seabed ground or a site where waves are strong and shearing force is strong.
When used as a bridge, it is preferable to cover the caisson 1 with a footing 88 so that the load of the bridge is uniformly applied to a cast-in-place foundation (for example, a hollow concrete column 76).
In addition, it can be applied to offshore wind power generation facilities, reaching shafts or starting shafts of the shield method.
[0050]
Next, a fourth embodiment will be described with reference to FIG.
[0051]
In the third embodiment of FIGS. 12 to 16, an embodiment in which one excavation hole H2 is excavated per one section C in the caisson 1 and a hollow concrete column 76 is formed using the excavation hole H2. Met.
[0052]
On the other hand, in the fourth embodiment of FIG. 17, in the example shown in the figure, a large excavation hole H3 is formed so as to penetrate the three sections D1, D2, and D3 and penetrate the ground improved region 8 below the caisson 1. In this embodiment, the large second caisson 10 is embedded in the excavation hole H3.
The second caisson 10 is the same as the third embodiment of FIGS. 12 to 16 except that the second caisson 10 is embedded in the three sections D1 to D3 of the caisson 1.
[0053]
The reason why the large second caisson 10 is embedded in the first caisson 1 is that, in the foundation structure on the soft submarine ground, the waves are strong and the shear force acts strongly. Examples of cases that can be used include offshore wind power generation facilities, the arrival of shield construction methods, and start shafts.
[0054]
Next, a fifth embodiment will be described with reference to FIGS. 18 and 19.
[0055]
18 and 19, when improving the lower seabed ground in the first caisson 1, the slime, which is a mixture of the soil and the solidified material of the ground G under the water surface generated in the solidified material injection process, is used as the first caisson. In the case where only one cannot be accommodated, another caisson 1B is towed by the tow ship 3 to be accommodated in another caisson 1B and brought close to the first caisson 1, and is moored by the mooring rope 30. Show.
Thereafter, the winch 35 provided in the first caisson 1 is rolled up, the first caisson 1 and another caisson 1B are brought into contact with each other, and slime is filled in another caisson 1B.
[0056]
As described above, another caisson 1B is arranged adjacent to the base caisson 1, and the slime that is a mixture of the soil and the solidified material of the ground G below the water surface is also accommodated in the other caisson 1B. Even when the amount of slime discharged is large, for example, processing such as carrying out and dumping to another place on the ground becomes unnecessary.
[0057]
It should be noted that the illustrated embodiments are merely examples, and are not intended to limit the technical scope of the present invention.
[0058]
【The invention's effect】
The effects of the present invention are listed below.
(1) By storing a fluid substance (slime), which is a mixture of soil and submerged soil under the surface of the water generated in the solidifying material injection process, in the container-like building, the generated slime is stored in the container-like building. It can be reused as a filling inside.
(2) Slime-filled container-like structures can be used as they are as revetments or artificial islands.
(3) By improving only the surface layer portion of the ground below the water surface in advance, the container-like building can be sufficiently supported by the improved surface layer portion.
(4) Cast-in-place foundations (for example, cast-in-place piles, steel pipe piles, hollow piles, etc.) through the flowable substance housed in the container-like building and the ground improved area below the container-like building Since the foundation that can construct the pile) is provided, utilizing the frictional force between the ground improved area under the container-like building and the fluid substance contained in the container-like building, Support force against external force in the horizontal direction can be obtained.
(5) A second container-like structure (for example, an elongated caisson) is embedded through the fluid substance contained in the container-like structure and the ground improved region below the container-like structure. By doing so, it is possible to configure the reaching shaft and the starting shaft using the caisson.
(6) By placing another container-like building on the base container-like building, a fluid substance that is a mixture of soil and solidified material under the surface of the water also in another container-like building. Even when the amount of fluid substance discharged is large, for example, it is not necessary to carry out processing such as carrying out or dumping to another place on the ground.
[Brief description of the drawings]
FIG. 1 is a first process diagram showing an initial process in carrying out a first embodiment of the present invention.
FIG. 2 is a top view showing a part of the upper surface of the caisson when carrying out the first embodiment of the present invention.
FIG. 3 is a second process diagram showing an intermediate process in carrying out the first embodiment of the present invention.
FIG. 4 is a process diagram showing a process near a final process when the first embodiment of the present invention is implemented.
FIG. 5 is a partial cross-sectional view showing the main part of a boring excavation process when carrying out the first embodiment of the present invention.
FIG. 6 is a partial cross-sectional view showing a main part when a solidifying material is ejected when carrying out the first embodiment of the present invention.
FIG. 7 is a first process diagram showing an initial process when carrying out a second embodiment of the present invention.
FIG. 8 is a second process diagram showing an intermediate process in carrying out the second embodiment of the present invention.
FIG. 9 is a third process diagram showing an intermediate process in carrying out the second embodiment of the present invention.
FIG. 10 is a fourth process diagram showing an intermediate process in carrying out the second embodiment of the present invention.
FIG. 11 is a process diagram showing a near final process when carrying out the second embodiment of the present invention.
FIG. 12 is a process diagram showing a process of drilling a drilling hole through the improved ground in an intermediate process when carrying out the third embodiment of the present invention.
FIG. 13 is a process diagram showing a process of inserting a double reinforcing bar into a drilling hole drilled in an intermediate process when carrying out the third embodiment of the present invention.
FIG. 14 is a process diagram showing a process for placing ready-mixed concrete in a double rebar insertion place of a drilling hole drilled in an intermediate process when carrying out the third embodiment of the present invention.
FIG. 15 shows a process of filling a hollow pile formed in the center of an excavation hole drilled in an intermediate process when carrying out the third embodiment of the present invention and cutting a new excavation hole. Process diagram.
FIG. 16 is a process diagram showing a final process in carrying out the third embodiment of the present invention.
FIG. 17 is a process diagram showing an intermediate process in carrying out the fourth embodiment of the present invention.
FIG. 18 is a process diagram showing an intermediate process in carrying out the fifth embodiment of the present invention.
FIG. 19 is a top view corresponding to FIG. 18;
[Explanation of symbols]
1 ... Caisson
2 ... Sea area
3 ... Towing ship
4 ... Construction machinery
5 ... Boring support device
6 ... Boring rod
7 ... Monitor
8 ... Improved area
B ... Submarine
C ... compartment
F ... Surface part
G ... Soil
Hb ... Boring hole
J ... Jet
T ... Improvement area

Claims (6)

A step of installing a container-like building on the ground below the surface of the water and installing a ground improvement device on the container-like building, and a region below the container-like structure of the ground below the water surface using the ground improvement device Boring in the vertical direction to insert the solidifying material injection means from the ground improvement device, injecting the solidifying material in the horizontal direction while rotating the solidifying material injection means, and pulling the solidifying material injection means upward A solidifying material injection step for improving the ground, and the waste discharged from the bottom of the water where the soil and solidifying material in the ground below the water surface generated during the solidifying material injection step are mixed in the container-like building A ground improvement method characterized by being housed in the ground. The ground improvement construction method according to claim 1, further comprising a step of improving the surface layer of the ground below the water surface prior to installing the container-like building on the ground below the water surface. 3. After leveling the surface layer of the ground below the water surface, before leveling the container-like structure on the ground below the water surface, performing a leveling step of flattening the surface layer improved by the ground surface Ground improvement method. The ground improvement construction method according to any one of claims 1 to 3, wherein a cast-in-place foundation is provided by penetrating a discharge housed in the container-like building and a ground-improved region below the container-like building. 4. The second container-like building is embedded in the second container-like building, penetrating through the discharge housed in the container-like building and the ground-improved region below the container-like building. Ground improvement method. Another container-like building is arranged with respect to the container-like building on which the ground improvement equipment is installed, and the flow that is a mixture of soil and solidified material in the ground below the surface of the water in the other container-like building. The ground improvement construction method of any one of Claims 1-5 which accommodates a sexual substance.

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