JP2920097B2 - Construction method and device for underground continuous wall - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for constructing a continuous underground wall for forming a continuous wall for waterproofing, foundation and the like underground.

[0002]

2. Description of the Related Art Conventionally, as a construction apparatus for forming an underground continuous wall, as shown in FIG. 4, a chain type cutter 2 is vertically mounted on a traveling cart (for example, a base machine of a crawler type crane). By rotating the vehicle 2 in the horizontal direction while traveling,
It is known to continuously excavate a groove G having a constant width (see JP-A-5-280043 and JP-A-5-280044).

[0003] The cutter 2 is an endless between a driving wheel (sprocket) 4 provided at an upper end of a cutter post 3 which is a box frame which is long vertically and an idler wheel (pulley) 5 provided at a lower end. The chain 6 is stretched over, and the groove G is excavated by a number of excavating blades 7 provided on the outer peripheral side of the chain 6.

An example of a construction method using this construction apparatus will be briefly described with reference to FIG.

(I) Excavation step As shown by a two-dot chain line in FIG. 5A, a cutter 2 is erected in a vertical hole excavated by an appropriate means, and the cutter 2 is horizontally moved with the traveling vehicle 1 while rotating the cutter 2. Thus, a continuous groove G having a predetermined length is excavated.

At this time, a drilling liquid (usually a bentonite aqueous solution) A is injected into the groove G for maintaining the excavated groove G, cooling the excavating blades 7...

(Ii) Solidifying liquid injection step As shown in FIG. 5B, the cutter 2 is moved to the excavation start end while the solidifying liquid (cement slurry) B is injected into the groove G, and the rotation of the cutter 2 is performed. The solidified liquid B and the drilling liquid A are stirred and mixed. At this time, a part of the drilling liquid A overflows and is discharged out of the groove.

(Iii) Re-stirring / mixing step As shown in FIG. 5 (c), the cutter 2 is moved to the end of excavation while rotating, thereby further stirring and mixing.

After the stirring and mixing, the soil cement, which is a mixture of the solidified liquid B, the excavated liquid A, and the in-situ soil (earth and sand generated by excavation) is solidified to form the wall C.

(Iv) Next Step Excavation Step As shown in FIG. 5D, a groove G having a predetermined length is excavated from the end of the formed wall body C.

[0011] By repeating the above steps, an underground continuous wall which is a continuous body of the wall C is formed.

[0012]

However, according to such a construction method, only the portion of the earth and sand generated in the excavated portion by the excavation, which overflows together with the excavation liquid A, is discharged out of the trench, and most of the soil remains in the trench. And mixed with the solidification liquid B as described above.

As a result, the continuous wall to be formed is not a pure cement wall, but a soil cement wall in which the drilling liquid A and a large amount of earth and sand are mixed in the solidified liquid B as described above.
The quality of the diaphragm was low.

When a core material such as an H-section steel is to be inserted into the solidified liquid, a method different from the above-mentioned method is to insert a steel cage and extrude concrete after the trench excavation to form a reinforced concrete wall. In some cases, it may be necessary to insert a steel or concrete panel into the groove and inject a solidifying liquid (eg, mortar) to join the panel and stabilize the panel. , It becomes difficult to insert the core material or the like.

In the excavated portion by the cutter 2, an upward flow is generated in the excavated liquid A in the excavated portion due to the rotation of the chain 6 (mainly the excavating blade 7), and the earth and sand floats on the liquid flow and is discharged. The action takes place.

However, since the generated liquid flow is diffused and weakened in the rear space, and the floating earth and sand is diffused in the groove, only a very small amount of earth and sand is discharged out of the groove. The effect was thin.

Accordingly, the present invention provides an underground continuous wall capable of efficiently discharging earth and sand generated by excavation to the outside of a trench by utilizing an upward flow of drilling fluid generated in a drilled portion by rotation of a cutter chain. A construction method and an apparatus are provided.

[0018]

According to the invention (construction method) of the present invention, an endless chain having an excavating blade is stretched over the upper and lower ends of a cutter post, and a chain type cutter is mounted on a traveling carriage. With the cutter installed in the ground, the cutter is rotated while pouring the drilling fluid, and is moved horizontally by the traveling carriage to continuously excavate a groove of a constant width. In the method of constructing an underground continuous wall by injecting and solidifying a solidified liquid in the groove, and forming an underground continuous wall, a partition plate on the outer surface of the cutter post, in the excavation direction ahead of the partition plate at the time of excavation. A pipe-shaped unloading space is provided in a state formed over substantially the entire length in the vertical direction, and drilling liquid is supplied to the unloading space while excavating a groove by the cutter, thereby performing excavation. The Flip sediment is intended to discharge into the groove outside by flotation together with the drilling fluid.

According to a second aspect of the present invention, in the configuration of the first aspect, the drilling fluid is supplied to the earth removal space while the trench is being drilled by the cutter, and the solidification fluid is injected into the space behind the partition plate in the direction of the drilling. It is.

According to a third aspect of the present invention, in the configuration of the first or second aspect, the compressed air is supplied to the earth discharging space from the lower end side.

According to a fourth aspect of the present invention (construction apparatus), a chain type cutter having an endless chain provided with an excavating blade spanned between upper and lower ends of a cutter post is attached to a traveling carriage, and the cutter is mounted on a ground. In the state where it was erected inside, it was rotated while pouring the drilling liquid, and it was horizontally moved by the traveling cart to continuously excavate a groove of a constant width, and the solidified liquid was poured into the excavated groove. In the construction apparatus for an underground continuous wall configured to inject and solidify to form an underground continuous wall, a partition plate is provided on an outer surface of the cutter post, and a pipe-shaped drain is provided ahead of the partition plate at the time of excavation. An earth space is formed so as to protrude over substantially the entire length in the vertical direction, and a cutter post is provided with a drilling liquid pipe for supplying drilling liquid to the earth discharging space.

According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the cutter post is provided with an air pipe for sending compressed air to the lower end side of the earth discharging space.

According to the above construction, a pipe-shaped discharging space is formed in the excavated portion by the partition plate while being substantially isolated from the rear space, and in this discharging space, the drilling liquid is directed upward by rotation of the cutter chain. The flow of
Sediment generated by excavation floats on this liquid flow and is discharged out of the ditch.

That is, since the earth floating and discharging action is concentrated only in the earth discharging space and the conventional liquid flow and the diffusion of the earth and sand in the groove are prevented, the soil discharging action is actively and efficiently performed. Can discharge most of the sediment.

[0025] For this reason, when a method of injecting cement into a groove as a solidifying liquid and solidifying the cement is adopted, a high-quality continuous wall with high cement purity can be formed.

Alternatively, when the method of inserting the core material, the reinforcing bar cage, and the panel is adopted, the insertion of the core material and the like is not hindered by earth and sand.

Further, the drilling liquid is supplied only to the earth discharging space,
And since it flows upwards in the same space, the amount of drilling liquid that enters the rear space is almost eliminated.

Therefore, even if the solidification liquid is injected into the rear space while digging, there is almost no possibility that the drilling liquid will be mixed with the solidification liquid.

According to the third and fifth aspects of the present invention, the upward air flow is assisted and enhanced by the compressed air, so that the earth discharging operation is more actively performed.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

In this embodiment, the same parts as those of the conventional construction apparatus shown in FIGS. 4 and 5 are indicated by the same reference numerals, and the description thereof will not be repeated.

Partition plates 8, 8 are attached to outer surfaces (hereinafter, referred to as abdominal surfaces according to a common name) 3a, 3a of the cutter 2 attached to the traveling carriage 1 in both directions perpendicular to the direction of excavation of the cutter post 3.

As shown in detail in FIGS. 2 and 3, the partition plates 8, 8 are provided at the front portions of the abdominal surfaces 3a, 3a in the direction of excavation.
In a state projecting at a right angle to a and 3a, the tip is attached to a length almost in contact with the inner surface of the groove G to be dug, and is attached over substantially the entire vertical direction excluding the lower end of the post.

With respect to the above-mentioned length of the partition plate, from the viewpoint of reducing the insertion resistance of the core material, the rebar cage, and the panel, the groove G is formed so as to discharge only the earth and sand exceeding a certain grain size.
The length may be such that a small gap is formed between it and the inner surface.

By providing such partition plates 8, 4 at the time of excavation, four rounds are substantially closed by the partition plates 8, 8, the cutter post 3, and the groove inner surface ahead of the partition plates 8, 8 in the excavation direction. Thus, a pipe-shaped discharging space S substantially isolated from the rear space is formed over substantially the entire vertical direction.

Drilling liquid pipes 9 and air pipes 10 are provided on both sides of the cutter post 3 in a direction orthogonal to the excavation direction over substantially the entire length of the post 3.

The lower ends of the two pipes 9 and 10 are respectively led out from the lower ends of the posts, and the lower discharge ports 9 are provided.
a, 10a face the earth discharging space S from below the partition plate 8.

On the other hand, the upper end of the drilling liquid pipe 9 is connected to a drilling liquid preparation unit, and the upper end of the air pipe 10 is connected to a compressor (both not shown) via hoses. Is drilling fluid piping 9
Compressed air supplied from the compressor to the discharge space S from the discharge port 9a through the discharge port 1a through the air pipe 10
0a are respectively sent to the earth discharging space S.

When the underground continuous wall is formed by this device, the excavating liquid A is injected into the unloading space S while excavating the groove G by the cutter 2 built in the ground, The solidification liquid B is injected backward.

In the case of this construction method, the drilling liquid A does not have the role of maintaining the groove G in the conventional construction method, but plays a role of cooling the excavating blade 7 and loosening the ground, and floating the soil as described below. It has the effect of discharging.

In FIG. 1, S1 is a sand puddle excavated in advance by a hydraulic shovel or the like on the ground surface in the excavation direction prior to the excavation work by the cutter 2 or as the excavation work proceeds. is there.

In this way, by injecting the drilling liquid A into the earth discharging space S while rotating the cutter 2 (chain 6) in the direction of arrow A in FIG.
..) Generates an upward flow in the drilling liquid A, and the upward liquid flow is assisted by blowing compressed air.

Thus, the earth and sand generated in the earth discharging space S by the excavation floats on the upward liquid flow, and the excavated liquid A
Sediment pool S excluding fines that overflow with
1 is stored.

As described above, the floating and discharging action of the earth and sand at the excavated portion is concentrated only in the earth discharging space S, and the diffusion of the liquid flow and the earth and sand in the conventional groove is suppressed, so that the earth discharging action is activated. It is performed efficiently.

Thus, since most of the earth and sand can be discharged, the solidified liquid B injected into the rear space does not mix with the earth and sand, and a high-quality continuous wall with high cement purity can be formed.

Further, when a core material such as an H-beam is inserted into the solidified liquid B, or when a method of forming a reinforced concrete wall by inserting a steel cage into the groove and hitting concrete as a separate method is adopted, When the panel is inserted into the mortar and the method of joining and stabilizing with a mortar is adopted, earth and sand do not hinder the insertion of the core material and the like.

The sediment accumulated in the sediment pool S1 is
A hydraulic excavator or the like may be used for scooping, or the excavated liquid may be sucked up with a hose and conveyed to a sediment separator, separated from the excavated liquid and discarded or reused as concrete aggregate or the like according to the particle size.

On the other hand, the earth discharging space S cannot actually be a completely closed space, and is in a state of communicating with the rear space at the bottom of the groove, but the drilling liquid A in the space S flows upward. thing,
And since the communication port is very small, there is almost no possibility that the drilling liquid A is mixed with the solidified liquid B.

Other Embodiments (1) In the above embodiment, the continuous construction method of injecting the solidified liquid B into the rear space while excavating is employed. After excavation while pouring the liquid, a method of pouring the solidified liquid B may be adopted.

Also in this case, the basic effect of the present invention that the earth and sand generated in the excavated portion can be efficiently discharged can be obtained.

Alternatively, a core material may be inserted into the solidified liquid B, or a method of inserting a reinforced cage and extruding concrete after digging a groove, or a method of inserting a steel or concrete panel into a groove and inserting a mortar. And a method of bonding and stabilizing may be employed.

(2) In the above embodiment, the compressed air is blown into the discharging space S together with the drilling liquid A in order to strengthen the upward liquid flow in the discharging space S. The upward liquid flow may be generated only by the rotation of the chain 6.

[0053]

As described above, according to the present invention, a pipe-shaped discharging space is formed in the excavated portion by the partition plate in a state substantially isolated from the rear space, and the cutter chain is formed in the discharging space. The upward rotation of the drilling fluid is generated by the rotation of the excavation fluid, and the sediment generated by the excavation is floated on this fluid flow and discharged out of the ditch, so the sediment lifting and discharging action is concentrated only in the discharging space However, since the diffusion of the liquid flow and the earth and sand in the grooves as in the related art is suppressed, the soil discharging action is actively and efficiently performed.

Thus, most of the earth and sand can be discharged, so that a high-quality continuous wall with high cement purity can be formed.

Further, when a core material is inserted into the solidification liquid, or when a method of forming a continuous wall of reinforced concrete or a method of inserting a panel and joining and stabilizing with the solidification liquid is employed, the earth and sand are removed from the core material or the like. Does not hinder insertion.

Further, since the drilling fluid is supplied only to the earth removal space and flows upward in the space, the amount of the drilling fluid entering the rear space is almost eliminated.

Therefore, even when the solidified liquid is injected into the rear space while excavating as in the second aspect of the present invention, there is almost no possibility that the excavated liquid is mixed with the solidified liquid.

On the other hand, according to the third and fifth aspects of the invention, the upward flow of liquid is assisted and strengthened by the compressed air, so that the earth discharging action is more actively performed.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a construction apparatus according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of the same device.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a schematic front view of a conventional construction apparatus.

FIGS. 5 (a), (b), (c) and (d) are views for explaining a conventional construction method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Traveling trolley 2 Chain type cutter 3 Cutter cutter post 6 Endless chain 4 Driving wheel over which a chain is hanged 5 Idling wheel 7 Drilling blade 8 Partition plate 9 Drilling liquid piping 10 Air piping G groove S Unloading space

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroaki Kondo 2-3-1 Shinhama, Arai-machi, Takasago City, Hyogo Prefecture Inside Kobe Steel, Ltd. Takasago Works (72) Inventor Masayuki Hamaguchi 2-3-3 Niihama, Araimachi, Takasago City, Hyogo Prefecture No. 1 Kobe Steel, Ltd. Takasago Works (72) Inventor Toshiyuki Ueda 2-3-1, Shinai, Araimachi, Takasago City, Hyogo Prefecture Kobe Steel Co., Ltd., Takasago Works (72) Inventor Takuya Izumiya Araicho, Takasago City, Hyogo Prefecture 2-3-1, Shinhama Kobe Steel, Ltd. Takasago Works (56) References JP-A-6-123117 (JP, A) JINKO Sho 57-12052 (JP, Y2) (58) Fields investigated (Int .Cl. ⁶ , DB name) E02F 5/02 E02F 5/06 E02D 5/18-5/20

Claims (5)

(57) [Claims] An endless chain provided with an excavating blade is attached to a traveling carriage by straddling between an upper end and a lower end of a cutter post. The cutter is rotated while pouring the liquid, and is continuously excavated in a groove of a constant width by being horizontally moved by the traveling cart. In the method of constructing an underground continuous wall for forming a continuous wall, a partition plate is formed on the outer surface of the cutter post, and a pipe-shaped discharge space is formed over the entire length in the vertical direction in front of the partition plate at the time of excavation in the excavation direction. The drilling fluid is supplied to the earth discharging space while the trench is being drilled by the cutter, so that the earth and sand generated by the drilling are floated together with the drilling fluid and out of the trench. An underground continuous wall construction method characterized by discharging. 2. The underground continuity according to claim 1, wherein the drilling fluid is supplied to the earth removal space while the trench is being drilled by the cutter, and the solidification fluid is injected into the space behind the partition plate in the direction of the drilling. Wall construction method. 3. The underground continuous wall construction method according to claim 1, wherein the compressed air is supplied to the earth discharging space from a lower end side. An endless chain having an excavating blade is attached to a traveling carriage by crossing the end between upper and lower ends of a cutter post, and the cutter is buried in the ground. By rotating while pouring the liquid, and moving horizontally by the traveling cart, a groove of a constant width is continuously excavated, and a solidified liquid is poured into the excavated groove to be solidified, and the underground continuous wall is formed. In the construction apparatus for an underground continuous wall configured to create a wall, a partition plate is provided on an outer surface of the cutter post, and a pipe-shaped discharge space is provided in the excavation direction ahead of the partition plate at the time of excavation over substantially the entire length in the vertical direction. While being protruded in the state formed by
An underground continuous wall construction apparatus, wherein a drilling liquid pipe for supplying drilling liquid to the above-mentioned earth removal space is provided on a cutter post. 5. The underground continuous wall construction apparatus according to claim 4, wherein the cutter post is provided with an air pipe for sending compressed air to a lower end side of the earth discharging space.