JP2000192453A - Method and apparatus for constructing underground continuous wall, and groove wall protective plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely construct an underground continuous wall in the soft ground in which a groove wall cannot be stabilized only by applying a slurry thereto, by using a groove wall protective plate and a slurry pressure alone without execution of auxiliary construction such as soil improvement which has been conventionally executed. SOLUTION: In this underground continuous wall construction method, a groove 2 is excavated while a slurry being charged thereinto by means of a continuous wall excavator, and efficiently and continuously excavated by filling mud of high gravity into the groove. Further, while a partitioner-cum-mud discharging device 3 discharges mud of high gravity within the excavated groove, it partitions the interior of the groove 2 to the groove 2 before the mud is discharged and the groove 2 after the mud is discharged. Alternatively, while the partitioner-cum-mud discharging device 3 extrudes the mud of high gravity within the excavated groove, it partitions the interior of the groove 2 to the groove 2 before the mud is extruded and the groove 2 after the mud is extruded. Further, a slurry of low gravity is supplied into the groove 2 after the mud is discharged or extruded. Then, reinforcing bars and/or steel frames are constructed in the thus excavated groove, and concrete is placed.

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 an underground continuous wall, and a formwork for retaining lands used for carrying out the method.

[0002]

2. Description of the Related Art In a conventional method of constructing a continuous wall, as shown in FIG. 11, when an underground wall (one element) having a large width B of usually 7 to 10 m is to be constructed on the ground 1, an excavation trench 1 is required.
The ditch is excavated by a continuous wall excavator while a low specific gravity stabilizing liquid is put in the stove 7 to stabilize the ditch wall. At this time, the excavation width (1 gut) that can be excavated at one time is b, and excavation of several guts is repeated to excavate the width B of one element. After completion of digging for one element, slime treatment is performed, a reinforcing bar is laid, concrete is poured, and a wall is built.

However, in such a series of operations, a trench excavation operation by a continuous wall excavator is performed by excavating several guts per element, so that the excavation operation requires a lot of labor and time. In addition, such excavation work involves a lot of uncertainties in the process, so that the efficiency of the entire continuous wall construction work cannot be improved.

[0004] For this reason, a chain saw type cutter device has been developed as one method of grooving machine of the soil cement continuous wall method. In this method, a trench excavated by a chainsaw type cutter is filled with high specific gravity mud, a solidifying material such as cement is added to the mud, a core material is built, and a soil cement wall is built.

According to this method, trench excavation is continuously performed,
It can be performed at a high speed. In addition, the excavation trench wall is held down by mud of high specific gravity and is stable, so that it can be continuously excavated. The length of the trench that can be dug is greatly improved, and it can be extended from several tens of meters to infinite length depending on the soil type.

[0006]

In the conventional method of constructing a continuous underground wall of a reinforced concrete wall, the length of a trench excavation (one element) per time is about 10 m, and excavation, rebar construction, and concrete casting are performed. Since the construction is performed while repeating the series of steps described above, the utilization rate of the machines used in each step is poor, and it takes time to replace the machines. In addition, in the soil cement underground continuous wall construction method, there is an advantage that the trench can be continuously excavated using a chain saw type cutter device or the like, but since the excavation trench is filled with high specific gravity mud, it is used as it is. In such a case, it was impossible to insert a reinforcing bar in the trench or cast concrete, and it was impossible to construct a concrete wall having high quality reliability.

The soil-cement continuous wall method is a method of stabilizing the ground and building the soil wall by stirring and kneading the soil of the ground and the solidifying material. Due to its high cost, it is an excellent construction method for the stability of the ground.However, because it is a soil cement wall of ground and solidified material, the strength varies, and the wall thickness is uneven due to unevenness of the wall. In addition, the wall has low strength due to poor vertical accuracy.

The present invention has been made to eliminate the above disadvantages.

[0009]

According to the method of constructing a continuous underground wall of the present invention, a ground is excavated from one side to another while a stabilizing liquid is injected by a continuous wall excavator to form a groove, and a high specific gravity is formed in the groove. A step of forming mud, a step of extruding the high specific gravity mud in the groove by using a partitioning and extruding device from one side to the other, and a step of forming a low specific gravity in the groove after the high specific gravity mud is extruded and partitioned. The method is characterized by comprising a step of supplying a stabilizing liquid and a step of placing concrete in the excavation groove to which the low specific gravity stabilizing liquid has been supplied.

In the method for constructing an underground continuous wall according to the present invention, the ground is excavated from one side to the other while a stabilizing liquid is injected by a continuous wall excavator to form a groove, and a high specific gravity mud is formed in the groove. A step of partitioning while discharging the high specific gravity mud in the groove from one side to the other by a partition and mud discharging device, and a low specific gravity stable liquid in the groove after the high specific gravity mud is discharged and partitioned. And a step of placing concrete in the excavation groove to which the low specific gravity stable liquid has been supplied.

[0011] The step of placing the concrete is performed by partitioning both end faces of one end of the groove after the high specific gravity mud is extruded or discharged and separated by a partition plate. Is provided.

[0012] The method for constructing an underground continuous wall according to the present invention is characterized in that the method further comprises a step of moving the groove wall protection plate from one side to the other relative to the cast concrete.

The partitioning and mud extruding apparatus of the present invention has a high specific gravity mud extruding means having an extruding means for extruding high specific gravity mud on a front surface thereof and a partitioning means on a rear surface thereof, and excavating the high specific gravity mud extruding means. And propulsion means for propelling from one side to the other in the groove.

The partitioning and mud discharging apparatus of the present invention has a high specific gravity mud separating and discharging means having an inlet for taking in high specific gravity mud on a front surface and a partitioning means on a rear surface, and the high specific gravity mud separating and discharging means. And propulsion means for propelling from one side to the other in the excavation trench.

The groove wall protection plate of the present invention is disposed opposite to the outer plate, a plurality of semicircular projecting portions provided on the inner surface of the outer plate so as to be spaced apart in the length direction, and the outer plate. An inner plate and an outward serrated portion located on the outer surface of the inner plate corresponding to the inward serrated portion.One end of the inward serrated portion is a vertical surface, and the other end is a slope. One end of the outward sawtooth-shaped portion is a slope, and the other end is a vertical surface.

The groove wall protection plate of the present invention comprises an outer plate, a plurality of mountain-shaped projecting portions provided on the inner surface of the outer plate so as to be spaced apart from each other in the length direction, and an inner plate arranged opposite to the outer plate. Board and
It is characterized by comprising a mountain-shaped protruding portion provided on the outer surface of the inner plate and corresponding to the mountain-shaped protruding portion.

Further, the groove wall protection plate of the present invention comprises: an outer plate;
A plurality of semi-arc-shaped projecting portions provided on the inner surface of the outer plate in the longitudinal direction, an inner plate disposed opposite to the outer plate, and the semi-arc formed on the outer surface of the inner plate; And a semicircular protruding portion positioned corresponding to the protruding portion.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

In the present invention, as shown in FIG. 1, a trench 2 is excavated in the direction of an arrow while injecting a stabilizing liquid into a ground 1 by a wall excavator (not shown). And a partitioning and mud discharging device 3 is set in the excavation groove 2 from behind the wall excavator, and the groove 2 is also moved in the direction of the arrow.
The high specific gravity mud in the inside is advanced while discharging, and the groove 2 after discharging the high specific gravity mud is partitioned by a partition plate (not shown).
A low specific gravity stabilizing liquid such as water is supplied into the partitioned groove 4 while discharging the high specific gravity mud, and both ends of a desired area of the partition groove 4 are partitioned by continuous wall partition plates 5 and 6, and the partition is performed. A groove wall protection plate 7 is provided on both walls of the groove 4 as necessary,
A reinforced basket 8 is put in an area surrounded by the partition plates 5 and 6 and the groove wall protection plate 7, and concrete 9 is cast as shown in FIG.

Next, the jack of the propulsion means 10 composed of, for example, a multi-stage jack is extended to apply a reaction force to the concrete 9 cast as shown in FIG. 3, and the partition and mud discharging device 3 is extruded in the direction of the arrow. The high specific gravity mud is discharged while the low specific gravity stable liquid is injected into the groove 4 partitioned by the partitioning and mud discharging device together with the groove wall protection plate 7 while the concrete 9 is cast. Backfill mortar 11 is injected into a gap formed after the groove wall protection plate 7 is pulled out between the grounds, and the propulsion means 10 is moved in a state where the groove wall protection plate 7 is separated from the concrete 9 cast. The steps of FIGS. 1 and 2 are repeated so that the jack is slightly reduced.

The above-mentioned partitioning and mud discharging device 3 is constituted by, for example, a high-specific-gravity mud separating and discharging means having a take-in port for taking in high-specific-gravity mud on the front surface and a partitioning means on the rear surface.

If the multistage jack of the propulsion means 10 cannot be stored in the partitioning and mud discharging device 3, FIG.
As shown in (1), the jack storage tube 12 may be extended from the partitioning and mud discharging device 3 in the traveling direction so that a part of the jack can be stored.

If the groove wall of the partition groove 4 is a ground where the ground is stable without being collapsed only by the low specific gravity stabilizing liquid, the groove wall protection plate 7 is unnecessary, but the ground is soft and low. When the ground is not stabilized only with the specific gravity stabilizing liquid, the groove wall protection plate 7 is used to reinforce the groove wall, and the ground improvement and the like can be omitted.

As shown in FIG. 5, for example, the groove wall protection plate 7 includes an outer plate 13, a plurality of inward saw-toothed portions 14 provided on the inner surface of the outer plate 13 in the longitudinal direction, and the outer plate 13. An inner plate 15 disposed opposite to the plate 13; and an outward sawtooth portion 16 provided on the outer surface of the inner plate 15 and corresponding to the inward sawtooth portion 14. Is a vertical surface, the other end is a slope, one end of the outwardly sawtooth-shaped portion 16 is a slope, and the other end is a vertical surface.

When the concrete is cast, the slope of the inward saw tooth portion 14 and the slope of the outward saw tooth portion 16 engage as shown in FIG.
The interval 18 between them is maximized.

When the groove wall protection plate 7 is pulled out, the inner plate 15 is moved relative to the outer plate 13 in the advancing direction and the inward and outward sawtooth portions 14, 16 as shown in FIG. If the vertical surfaces are engaged with each other, the space 18 between the outer plate 13 and the inner plate 15 is minimized in this state, so that the groove wall protection plate 7 can be easily pulled out.

In another embodiment of the present invention, as shown in FIG. 7, the serrated portions 14, 16 may be replaced by mountain-shaped projecting portions 19, 20, or as shown in FIG. The projecting portions 21 and 22 may be used.

In this embodiment, when pulling out the groove wall protection plate 7, if the inner plate 15 is moved in the traveling direction relative to the outer plate 13 as shown in FIG. 9 or FIG. The gap 18 between the plate 13 and the inner plate 15 is minimized, and if the outer plate 13 and the inner plate 15 are simultaneously pulled, the groove wall protection plate 7 can be easily pulled out.

Further, in the present invention, instead of using the above-mentioned partitioning and mud discharging device 3, for example, a high-specific-gravity mud separating and extruding means having a pushing means for extruding high-density mud on the front face and a dividing means on the rear face is provided. Alternatively, the extruded high specific gravity mud may be discharged by a desired discharging means while extruding the high specific gravity mud.

[0030]

The method for constructing a continuous underground wall according to the present invention is as described above, and the following effects can be obtained.

Since the excavation can be performed continuously, the excavation speed is high and the construction cost can be greatly reduced.

Since the partitioning and mud discharging or extruding device is always immersed in the groove, the center of gravity is low and the safety of work is high.

Since an excavator having an expensive mechanical loss can be used continuously without waiting, the construction period can be shortened and the cost can be reduced.

When the ground is soft and lacks independence, the groove wall protection plate is used, so that an auxiliary construction method such as ground improvement is not required, and the construction period and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view for explaining a method for constructing an underground continuous wall according to the present invention.

FIG. 2 is a plan view for explaining a method of constructing an underground continuous wall according to the present invention.

FIG. 3 is a plan view for explaining a method of constructing an underground continuous wall according to the present invention.

FIG. 4 is a plan view of another embodiment of a partition and mud discharging device used in the method for constructing an underground continuous wall according to the present invention.

FIG. 5 is an explanatory plan view of a groove wall protection plate used in the method for constructing an underground continuous wall according to the present invention.

FIG. 6 is an explanatory plan view of a groove wall protection plate used in the method for constructing an underground continuous wall according to the present invention.

FIG. 7 is a plan view for explaining another embodiment of the groove wall protection plate used in the method for constructing an underground continuous wall according to the present invention.

FIG. 8 is a plan view for explaining another embodiment of the groove wall protection plate used in the method for constructing an underground continuous wall according to the present invention.

FIG. 9 is a plan view for explaining another embodiment of the groove wall protection plate used in the method for constructing an underground continuous wall according to the present invention.

FIG. 10 is a plan view for explaining another embodiment of the groove wall protection plate used in the method for constructing an underground continuous wall according to the present invention.

FIG. 11 is an explanatory view of a conventional underground continuous wall construction method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ground 2 Groove 3 Partition and mud discharging device 4 Groove filled with low specific gravity stabilizing liquid 5 Partition plate for newly constructed continuous underground wall 6 Partition plate for existing built underground wall 7 Groove wall protective plate 8 Reinforcing cage 9 Concrete Reference Signs List 10 Propulsion means 11 Backfill mortar 12 Jack storage tube 13 Outer plate of groove wall protection plate 14 Inward saw tooth portion 15 Inner plate of groove wall protection plate 16 Outward saw tooth portion 17 Drilling groove 18 Spacing of groove wall protection plate 19 Mountain shape Projecting portion 20 Mountain-shaped projecting portion 21 Semi-arc-shaped projecting portion 22 Semi-arc-shaped projecting portion

Claims (9)

[Claims] A step of forming a groove by excavating the ground from one side to the other while injecting a stabilizing liquid by a continuous wall excavator, and forming a high specific gravity mud in the groove; A step of partitioning while extruding the high specific gravity mud from one side to the other; a step of supplying a low specific gravity stable liquid into the groove after the high specific gravity mud is extruded and partitioned; and A step of casting concrete in the supplied excavation trench portion, comprising: 2. A step of excavating the ground from one side to the other while injecting a stabilizing liquid with a continuous wall excavator to form a groove, and forming a high specific gravity mud in the groove, A step of partitioning the high specific gravity mud in the groove while discharging it from one side to the other; a step of supplying a low specific gravity stable liquid into the groove after the high specific gravity mud is discharged and partitioned; Casting concrete in the excavation trench to which the liquid has been supplied. 3. The step of placing concrete includes partitioning both end faces of one end of the groove after the high specific gravity mud is extruded or discharged and partitioned, and arranging groove wall protection plates on both side walls. 2. The method according to claim 1, further comprising the step of:
Or the method for constructing an underground continuous wall according to 2. 4. Relative to said cast concrete,
4. The underground continuous wall construction method according to claim 1, further comprising a step of moving the groove wall protection plate from one side to the other side. 5. A high specific gravity mud separating and extruding means having an extruding means for extruding high specific gravity mud on a front surface and a partition means on a rear surface, and propelling the high specific gravity mud extruding means from one side to the other in a digging groove. And a mud extruding device comprising: 6. A high specific gravity mud partitioning / discharging means having an intake for taking in high specific gravity mud on a front surface and a partitioning means on a rear surface, and the high specific gravity mud separating / discharging means being provided from one side to the other within a drilling groove. And a mud discharging device comprising a propelling means for propelling the mud. 7. An outer plate, a plurality of inward saw-toothed portions provided in the inner surface of the outer plate in the longitudinal direction, an inner plate arranged opposite to the outer plate, and an inner plate of the inner plate. One end of the inward sawtooth portion is a vertical surface, the other end is a slope, and one end of the outward sawtooth portion is formed of an outward sawtooth portion provided corresponding to the inward sawtooth portion provided on the outer surface. A groove wall protection plate, wherein the side is a slope and the other end is a vertical surface. 8. An outer plate, a plurality of mountain-shaped protruding portions provided on the inner surface of the outer plate in the longitudinal direction, an inner plate arranged opposite to the outer plate, and an inner plate of the inner plate. A groove wall protection plate comprising: a mountain-shaped protruding portion provided on an outer surface corresponding to the mountain-shaped protruding portion. 9. An outer plate, a plurality of semicircular projecting portions provided on the inner surface of the outer plate so as to be spaced apart from each other in the length direction, an inner plate arranged opposite to the outer plate, and the inner plate. And a semi-arc-shaped protruding portion provided on the outer surface of the groove wall corresponding to the semi-arc-shaped protruding portion.