JP3532449B2 - Excavation stirring device and ground improvement method using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digging and stirring apparatus used in a ground improvement method for stirring and mixing the ground while excavating the ground with a solidifying material sprayed from a spraying nozzle of a drilling rod, and a ground improvement method using the same. It is about.

[0002]

2. Description of the Related Art For example, for foundation slabs and parking lots of existing structures, or roads, railroad tracks, and other existing structures, where there is a possibility of sinking or collapsing under the bottom slab When the ground is improved by stirring and mixing, the improved body is constructed with a circular cross section whose radius is the length from the center of the excavating rod to the tip of the stirring blade protruding from it. However, it is necessary to form a drill hole having a diameter corresponding to the diameter of the improved body.

In this case, if the number of improved bodies to be constructed is large, it is necessary to dismantle and remove the entire concrete of the slab, and it is necessary to newly construct and restore the concrete slab after the improved body is constructed. Occurs.

Further, when the ground under the railroad is improved, the presence of sleepers laid under the rails makes it possible to construct an improved body having a diameter larger than the interval between the sleepers while the railroad is in use. Can not.

In the method of agitating and mixing the excavated soil and the solidified material by injecting the liquid solidified material from the injection nozzle attached to the lower end of the excavation rod, the solidified material is injected at a high pressure. Since the excavated soil and the solidified material in the mixed area are put under high pressure, there is a risk of collapsing the surrounding ground if the underground pressure is not relieved.

In view of the above background, the present invention provides a drilling and stirring device using an injection nozzle for constructing an improved body without forming a drill hole having a diameter corresponding to the diameter of the improved body, and a surrounding area when the injection nozzle is used. It proposes an excavator and agitator that prevents the collapse of the ground.

[0007]

According to a first aspect of the present invention, the stirring blade is opened and closed as the excavation rod rotates, so that the excavation stirring device descends with respect to the bottom slab of the existing structure with the stirring blade closed. It is possible to construct an improved body having a diameter larger than the diameter of the drilling hole under the bottom slab or the like only by forming the drilling hole having a size as large as possible.

The excavation rod has an injection nozzle for injecting a liquid solidified material toward the outside, and the outer periphery of the excavation rod is insulated from the rotation of the excavation rod, and ejects when the excavation rod rotates in either direction. A sleeve having an injection port that matches the nozzle and communicates with the nozzle is mounted.

On the outer circumference of the sleeve, an open / close stirring blade having an injection passage that opens and closes by rotating with respect to the sleeve as the excavating rod rotates and that is in communication with the injection port of the sleeve is rotatably connected.

The open / close stirring blade rotates with respect to the sleeve when the excavating rod rotates in either direction and the jet port of the sleeve matches the jet nozzle of the drill rod, and the jet passage matches the jet port of the sleeve. To do. The open / close stirring blade is closed when the excavating rod rotates in the direction opposite to the one direction, and at the same time, the sleeve rotates with respect to the excavating rod and the jet nozzle and the jet nozzle are separated.

In the excavating and agitating device of claim 1, when the ground improvement body is constructed under the bottom slab of an existing structure, the excavating rod rotates in the direction in which the open / close stirring blade is closed as described in claim 2. By doing so, with the open / close stirring blade closed, it descends through the excavation hole preformed in the bottom slab such as concrete slab or the surface ground, and the bit and claw at the tip of the drilling rod precede the bottom slab and the ground below the surface ground. Excavate.

After that, when the excavating rod is rotated in the direction in which the opening / closing stirring blade opens, the injection port of the sleeve matches the injection nozzle of the drilling rod, and the opening / closing stirring blade opens so that the injection path of the sleeve ejects. The ground improvement body having a radius larger than the length of the opening / closing stirring blade is constructed by agitating and mixing the solidified material and the excavated soil injected from the injection path through the injection nozzle and the injection port in the state matching the mouth.

In this case, after the ground improvement body is constructed, the excavator and agitator rotates the excavator rod in a direction in which the open / close agitator is closed to rotate the agitator blade with respect to the sleeve and close it. Be lifted.

Since the open / close stirring blade is held in the closed state by the inner peripheral surface of the drill hole when the drill stirring device descends in the drill hole, the drill stirring device when the open / close stirring blade is closed is installed in the drill hole. It only needs to be large enough to pass, and a diameter smaller than the diameter of the ground improvement body to be constructed is sufficient. As a result, even when the number of ground improvement bodies to be constructed is large, it is not necessary to dismantle and remove the entire concrete of the bottom slab and restoration work.

When the construction target is a railway line, the area of the excavation stirring device when the opening / closing stirring blade is in a closed state is set to a size that fits within the interval between the sleepers, so that the construction can be performed without removing the sleepers. It is possible to construct a ground improvement body having a diameter larger than the interval between sleepers on the ground under the track while the track is in use.

According to a third aspect of the present invention, in the excavation and agitation apparatus according to the first aspect, by fixing the fixed agitation blade on the outer circumference of the excavation rod above or below the opening and closing agitation blade, the fixed agitation blade of the excavation agitation apparatus can be used during the excavation. It is possible to agitate the excavated soil in the excavation hole whose radius is the length and to vacate it.By loosening the ground by digging, the pressure at the time of injection of the solidifying material is relaxed, and there is a risk of collapsing the surrounding ground. To avoid.

In this case, a hollow hole is formed on the ground improvement body constructed by the injection of the solidifying material, so that an escape place for the excavated soil and the solidifying material placed under high pressure is secured and solidification is achieved. Since the pressure in the mixing and mixing areas at the time of material injection is relieved, collapse of the surrounding ground is prevented.

In the excavating and agitating device of the third aspect, when the excavation hole is dug only by the fixed agitating blade, the excavating rod is rotated in the direction in which the open / close agitating blade is closed as described in the fourth aspect. While the open / close stirring blade is closed, the ground is excavated while forming a drill hole having a radius corresponding to the length of the fixed stirring blade until the drill rod reaches the support layer.

Thereafter, as the excavating rod rotates in the direction in which the open / close stirring blade opens, the injection port of the sleeve matches the injection nozzle of the excavating rod, and the open / close stirring blade opens to inject the injection path of the sleeve. A ground improvement body having a radius larger than the length of the opening / closing stirring blade is constructed by injecting the solidifying material from the injection passage of the opening / closing stirring blade in the state matching the opening and the injection nozzle and the injection port.

[0020] When the ground on the ground improvement body is dug, the excavation stirring device of claim 1 or 3 is provided with a pawl on the opening / closing stirring blade and the opening / closing stirring blade is opened. It can also be done by lowering. In these cases, the opening / closing stirring blade opens up to the construction depth of the ground improvement body,
Although the injection path matches the injection port and the injection nozzle, the excavation hole is formed without injecting the solidified material.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIGS. 2, 3 and 9, an excavating and agitating device 1 according to a first aspect of the present invention includes an excavating rod 2 having an injection nozzle 22 to which an excavating claw 5 or a bit is connected, and an excavating rod. A sleeve 3 is attached to the outer periphery of the rod 2 in a state of being insulated from the rotation of the excavation rod 2, and an open / close stirring blade 4 rotatably connected to the outer periphery of the sleeve 3 to open and close as the excavation rod 2 rotates. .

As shown in FIGS. 1 to 3, the sleeve 3 is rotatable about the axis of the excavating rod 2 by a predetermined angle while restraining the vertical movement of the excavating rod 2 or limiting the movement to a certain amount or less. The open / close stirring blade 4 is attached to the sleeve 3 so as to be rotatable about a horizontal axis or an axis inclined to some degree with respect to the horizontal as shown in FIG.

As shown in FIG. 2, an inner pipe 21 for supplying a liquid solidifying material to a jet nozzle 22 is fixed inside the excavating rod 2, and at least one of the inner pipe 21 is opened and closed when it is opened. The injection nozzle 22 is fixed to the blade 4 side. Inner pipe
21 is fixed to the drilling rod 2 and rotates with the drilling rod 2.

The sleeve 3 is formed with an injection port 31 which is in communication with and in communication with the injection nozzle 22 when the excavation rod 2 is rotated in either direction, and the opening / closing stirring blade 4 has an injection port 31 when opened.
An injection path 41 that communicates with the injection nozzle 22 and the injection port 31 is formed in conformity with 31.

In the drawing, the injection nozzle 22 is directed to the side of the one open / close stirring blade 4, and the injection nozzle 22 is attached to the one open / close stirring blade 4.
Forming an injection path 41 communicating with the injection path 41 of the sleeve 3.
Although the injection port 31 communicating with the injection nozzle 22 is formed at a position corresponding to, the injection nozzle 22 is directed toward both the open / close stirring blades 4 and 4 and the injection path 41 is formed in the open / close stirring blades 4 and 4. At the same time, the injection port 31 may be formed at the position of both the open / close stirring blades 4 and 4.

The injection nozzle 22 is fixed to the inner pipe 21 while straddling a hole formed between the inner peripheral surface and the outer peripheral surface of the excavating rod 2 and the inner pipe 21, and the injection port 31 is formed on the inner peripheral surface of the sleeve 3. It is formed by forming a hole between the surface and the outer peripheral surface, or by inserting a pipe into the hole. When the jet 31 coincides with the jet nozzle 22, the jet 31 communicates with the jet nozzle 22 directly or through the hole of the drill rod 2.

The injection path 41 is provided with a pipe on the lower surface of at least one of the opening / closing stirring blades 4 and 4 connected to the sleeve 3.
Alternatively, it is formed by fixing a member having a groove-shaped cross section or a C-shaped cross section as shown in FIG. 4, or by forming a hole in the opening / closing stirring blade 4 in the length direction or by incorporating a pipe therein. .

When the injection passage 41 is formed by fixing a pipe or forming a hole, the opening / closing stirring blade 4 is opened at the end face of at least one of the injection port 31 and the injection passage 41 which communicate with each other, and the injection passage 41 is opened. If necessary, a sealant is attached to ensure the adhesion between both when 41 is aligned with the injection port 31 and to prevent a loss of pressure when the solidified material is injected from the injection nozzle 22.

As shown in FIG. 4, when a member having an open cross section is fixed to the lower surface of the opening / closing stirring blade 4 to form the injection passage 41, the injection port 31 of the sleeve 3 is formed by inserting a pipe into the hole of the sleeve 3. It is formed so as to project from the outer peripheral surface of the sleeve 3 toward the opening / closing stirring blade 4 side and overlap the injection passage 41, and the injection passage 41 is arranged so as to be located above the injection port 31 when the opening / closing stirring blade 4 is opened. .

When the injection path 41 is formed of a member having an open cross-section, the injection path 41 may be clogged with earth and sand when the solidifying material is not injected, but if the injection is started, the injection port 31
Since the solidified material injected from the device can remove the soil in the injection path 41, the injection path 41 is prevented from being clogged.

As shown in FIG. 2, the sleeve 3 is opposite to the excavation rod 2 when the excavation rod 1 rotates in one direction (forward rotation in the drawing) with respect to the excavation rod 2. It rotates around the axis by a certain angle and is locked to the excavation rod 2, and the injection port 31 matches the injection nozzle 22 and communicates therewith.

When the excavating rod 2 rotates in the opposite direction (reverse rotation), the sleeve 3 is moved to the excavating rod 2 as shown in FIG.
It rotates in the opposite direction to a certain angle and is locked to the excavation rod 2. At the same time that the drill rod 2 rotates in the reverse direction, the injection port 31 separates from the injection nozzle 22.

The open / close stirring blade 4 rotates and opens with respect to the sleeve 3 as shown in FIG. 2 when the excavating rod 2 rotates in either direction (forward rotation), and at the same time, is completely opened, and at the same time, jetting is performed. The passage 41 coincides with the injection port 31 and communicates with it. When the excavation rod 2 rotates in the opposite direction (reverse rotation), the sleeve 3 is rotated and closed as shown in FIG.
41 separates from the jet 31.

An upper stopper 6 and a lower stopper 7 are provided on the outer circumference of the excavating rod 2 above and below the mounting position of the sleeve 3 so as to restrain the vertical movement of the sleeve 3 with respect to the excavating rod 2 or to limit it to a certain amount or less. It Upper stopper 6
Also has a role of holding the open / close stirring blade 4 so as not to rotate further upward when the open / close stirring blade 4 changes from the closed state to the open state, and the lower stopper 7 rotates the open / close stirring blade 4 downward. It also has the function of holding it so that it does not close.

On the outer circumference of the excavating rod 2, a locked portion 23 for locking the sleeve 3 when the opening and closing stirring blade 4 is closed and opened is formed or projected, and the opening and closing stirring blade on the inner circumference of the sleeve 3 is formed. A locking portion 32 that locks with the locked portion 23 is formed or provided at a position corresponding to the locked portion 23 at the time of closing and opening of 4.

FIG. 5 shows a sleeve 3 to which an open / close stirring blade 4 is connected, and FIG. 6 shows a lower stopper 7 integrated with a drilling rod 2
Are shown respectively. FIG. 5- (a) shows a state when the open / close stirring blade 4 connected to the sleeve 3 is closed, and (b) shows a state when the open / close stirring blade 4 is opened. 6- (a) to (c) show the drilling rod 2
An example of the shape of the lower stopper 7 integrated with the above is shown.

In FIGS. 6 and 8, the upper stopper 6 and the lower stopper 7 are formed in such a manner that the open / close stirring blade 4 is rotated downward to be closed and is rotated upward to be opened.
As shown in (b), when the open / close stirring blade 4 is rotated upward to be closed and rotated downward to be opened, the shapes of the upper stopper 6 and the lower stopper 7 are reversed.

In the drawings, as shown in FIGS. 2 and 3, the sleeve 3 rotates 90 ° around the axis of the excavating rod 2 so that the open / close stirring blade 4 can be switched between the closed state and the open state. The locked portion 23 and the locking portion 32 are formed at two points of point symmetry, but it suffices if both the locked portion 23 and the locking portion 32 are formed at at least one location.

Since the sleeve 3 is insulated from the rotation of the excavating rod 2, until the engaging portion 32 engages with the engaged portion 23 in the direction opposite to the rotation direction of the excavating rod 2 as shown in FIG. After the rotation, the locking portion 32 is locked to the locked portion 23, the locking portion 32 and the drilling rod 2 rotate in the same direction as the drilling rod 2.

In the drawing, the drilling rod 2 is positive (clockwise)
When rotating, the engaging portion 32 engages with the engaged portion 23 in the reverse rotation direction (counterclockwise) to open the opening / closing stirring blade 4, and when the excavating rod 2 rotates in the opposite direction, the engaging portion 32. Is engaged with the engaged portion 23 in the direction of normal rotation to form the engaged portion 23 and the engaging portion 32 so that the opening / closing stirring blade 4 is closed, but when the excavating rod 2 rotates in the reverse direction. The open / close stirring blade 4 is opened to the open position, and the locked portion 23 and the locking portion are closed so that the open / close stirring blade 4 is closed when rotating forward.
It may form 32.

FIG. 6- (a) shows between the upper stopper 6 and the lower stopper 7, the upper stopper 6 fixed to the excavation rod 2 after mounting the sleeve 3 and the lower stopper fixed in advance. A holding material 8 for holding a space between
It shows the case where the bridge is installed in two places.

The holding member 8 also functions to stop the sleeve 3 after rotating the sleeve 3 with respect to the excavating rod 2 by a certain angle, instead of the engaged portion 23 of the excavating rod 2 or together with the engaged portion 23. To do. When the holding material 8 has a role of replacing the locked portion 23 of the drill rod 2, the locked portion of the drill rod 2
It is not necessary to form 23 and the locking portion 32 of the sleeve 3.

The open / close stirring blade 4 is horizontal to the plate 33 integrated with the outer periphery of the sleeve 3 by a pin 34 as shown in FIG. 1, or about an axis inclined to some extent with respect to the horizontal as shown in FIG. It is rotatably connected. In the case of the drawing, the opening / closing stirring blade 4 is opened by the resistance of the soil in the reverse direction when the excavating rod 2 is normally rotated and is guided by the guide along the edge of the lower stopper 7 as described later. It is closed by the resistance of the opposite direction and the guide of the lower stopper 7.

When the opening / closing stirring blade 4 is rotated downward to be closed and is rotated upward to be opened, the upper and lower surfaces are inclined with respect to the horizontal as shown in FIGS. In addition to the resistance of soil in the reverse direction when the rod 2 rotates forward, the resistance of soil in the upward direction when the excavation rod 2 descends causes switching from the closed state to the open state, and also when the excavation rod 2 rotates in the reverse direction. The resistance of the soil in the positive rotation direction and the resistance of the downward soil when the excavating rod 2 rises also switches from the open state to the closed state.

For example, when the opening / closing stirring blade 4 is provided with a claw and the excavation stirring device 1 is advanced to form an excavation hole 10 of a size having the length of the opening / closing stirring blade 4 as a radius, the ground is dug. The excavation and agitation device 1 descends while rotating forward.

When the excavating rod 2 rotates forward and the open / close stirring blade 4 is opened, as shown in FIG. 7- (c), the sleeve 3
It is possible to lock the opening / closing stirring blade 4 downwardly to the lower stopper 7 and upwardly to the upper stopper 6 while the locking portion 32 of the above is locked to the locked portion 23 of the excavating rod 2 in the reverse rotation direction. Therefore, the open / close stirring blade 4 is kept open.

When the excavating rod 2 is rotated in the reverse direction and the opening / closing stirring blade 4 is closed, the opening / closing stirring blade 4 is disengaged from the lower stopper 7 as shown in FIG.
Is locked to the locked portion 23 of the excavating rod 2 in the direction of normal rotation, so that the open / close stirring blade 4 is maintained in the closed state.

FIG. 7 shows the combination of the opening / closing stirring blade 4 and the drilling rod 2 in the case where the sleeve 3 with the opening / closing stirring blade 4 shown in FIG. 5 and the drilling rod 2 with the lower stopper 7 shown in FIG. 6- (b) are combined. The relationship between the lower stopper 7 and the lower stopper 7 is shown.

FIG. 7- (b) shows a state in which the excavating rod 2 is started to rotate forward. In this state, the opening / closing stirring blade 4 receives the resistance of the soil in the reverse rotation direction, so that the locking portion 32 is disengaged from the locked portion 23, and the opening / closing stirring blade 4 rotates together with the sleeve 3 while the lower stopper 7 is rotated. It is opened by being guided to the edge of. When the ground is dug by the open / close stirring blade 4 with a claw, the excavating rod 2 descends at the time of forward rotation, so the open / close stirring blade 4 is also opened by receiving upward resistance of soil.

Opening and closing the stirring blade 4 from the closed state,
Maintaining the open state and conversely closing from the open state and maintaining the closed state are also not shown, but also the outer peripheral surface of the pin 34 penetrating the opening / closing stirring blade 4 and the pin 34.
Each of the drilling rods 2 is attached to the inner peripheral surface of the insertion hole through which 34 passes.
It is also ensured by forming a locked portion and a locking portion such as the locked portion 23 and the locking portion 32 of the sleeve 3.

In this case, when the open / close stirring blade 4 is opened, the engaging portion of the insertion hole is engaged with the engaged portion of the pin 34 formed at that position in the opening direction, and the excavating and stirring apparatus 1 is By continuing to descend, the opening / closing stirring blade 4 is maintained in the open state, and when the opening / closing stirring blade 4 is closed, the locking portion of the insertion hole is closed to the locked portion of the pin 34 formed at that position. , And the excavation and agitation device 1 keeps rising to maintain the closed state.

The lower stopper 7 is formed by notching the closing position of the opening / closing stirring blade 4 as shown in FIGS. 6 (a) and 6 (c), or as shown in FIGS. 6 (a) and 6 (b). The distance between the edge of the lower stopper 7 and the center of the excavating rod 2 is gradually shortened from the open position of the open / close stirring blade 4 to the closed position, so that the open / close stirring is performed at the closed position of the open / close stirring blade 4. The shape is such that no collision with the wing 4 occurs.

As shown in FIGS. 6- (a) and 6- (b), the lower stopper 7 is
The distance between the edge of the drill and the center of the drilling rod 2 is the opening / closing stirring blade 4
When the lower stopper 7 is gradually shortened from the open position to the closed position, the lower stopper 7 smoothly opens and closes the opening / closing stirring blade 4 from the closed state along the edge of the lower stopper 7 and from the open state. have.

In FIG. 8, the upper surface of the lower stopper 7 is inclined downward from the open position to the closed position of the opening / closing stirring blade 4 so that the opening / closing of the opening / closing stirring blade 4 in contact with the upper surface of the lower stopper 7 is guided. , Shows the case where the opening from the closed state and the closing from the open state are performed smoothly. Here, by making the lower stopper 7 absent at the closed position of the opening / closing stirring blade 4, the collision between the opening / closing stirring blade 4 and the lower stopper 7 does not occur at the closing position of the opening / closing stirring blade 4.

If the upper and lower stoppers 6 and 7 shown in FIG. 8 are interchanged, the open / close stirring blade 4 can be closed upward as shown in FIG. 12- (b). FIG. 9 shows the whole excavation and agitation device 1 of claim 1. (a) shows the state where the open / close stirring blades 4, 4 are open, and (b) shows the state when the excavating rod 2 rotates 90 ° from the state of (a) and the open / close stirring blades 4, 4 are closed. Indicates the status. In all the drawings, the opening / closing stirring blades 4 and 4 have no claws.
In some cases, a claw may be protrudingly provided at the lower end of the.

FIG. 10 shows a construction procedure when the method of claim 2 is constructed by using the excavating and stirring apparatus 1 shown in FIG. The second aspect is a method of constructing the ground improvement body 11 under the bottom slab of an existing structure.

As shown in (a) and (b), the excavating rod 2 is rotated in either direction (reverse rotation in the drawing), and the excavating rod 2 is supported by the support layer while the open / close stirring blades 4 and 4 are closed. Until it reaches 9, the ground is excavated by the excavation claws 5 and bits at the tip of the excavation rod 2. Closed open / close stirring blades 4, 4
When it is necessary to form a drill hole 10 having a cross section surrounding the drill bit, a bit having a corresponding size is connected to the tip of the drill rod 2.

Further, for the purpose of relaxing the pressure in the mixing and mixing regions at the time of solidifying material injection at the construction position of the ground improvement body 11, while excavating the ground by the open / close stirring blades 4 with claws, the excavation stirring device 1 When advancing, the excavation and agitation device 1 rotates forward and descends with the open / close agitation blades 4 and 4 open.

When the tip of the excavating rod 2 reaches the support layer 9, the excavating rod 2 is rotated in the opposite direction (normal rotation in the drawing) to open the open / close stirring blades 4, 4 as shown in (c). At the same time, as shown in (d), the solidification material is sent to the inner pipe 21 at a high pressure while pulling up the excavation rod 2, and the injection nozzle 22
The solidifying material is injected from the injection path 41 through.

As it is shown in (e), the open / close stirring blades 4,
The rotation of the excavation rod 2 and the injection of the solidifying material are continued until 4 rises to the target depth, and the construction is completed when the construction of the ground improvement body 11 is completed. The ground improvement body 11 is completed with a radius larger than the length of the opening / closing stirring blade 4, the excavation stirring device 1 rotates in the reverse direction, and the opening / closing stirring blades 4 and 4 are pulled out in a closed state.

11 to 13 show an example of the construction of the excavating and stirring apparatus 1 according to claim 3, wherein the fixed stirring blades 12, 12 are fixed above or below the opening / closing stirring blades 4, 4 on the outer circumference of the drilling rod 2. . Figure 11
Shows the case where the fixed stirring blades 12, 12 are arranged below the opening / closing stirring blades 4 and 4, and FIGS. 12 and 13 show the case where they are arranged above the opening / closing stirring blades 4 and 4.

The fixed stirring blades 12 and 12 are fixed while stirring the excavated soil of the excavation claw 5 and the excavation hole 10 excavated by the bit at the time of the excavation stirring device 1 or while excavating the ground together with the excavation claw 5 and the bit. Drilling hole 10 with radius of stirring blade 12
The earth is agitated to make a hollow excavation, and it is projected so as to loosen the ground by empty excavation. When the ground is excavated by the fixed stirring blades 12, claws are projected from the lower end portions of the fixed stirring blades 12, 12.

FIG. 13 is for protecting the hole wall of the excavation hole 10 and for excavating and agitating device 1 in the excavation hole 10 especially in the case of boring.
The case where the stabilizer 13 is fixed to the tip of the fixed stirring blade 12 in order to ensure the stability of FIG.

FIG. 14 shows a construction procedure when the method of claim 4 is constructed using the excavation and agitation device 1 shown in FIG. The fourth aspect is a method of constructing the ground improvement body 11 under the hollow excavated hole 10, and the construction procedure is the same as in the case of FIG.

As shown in (a) and (b), the length of the fixed stirring blade 12 is set with the excavating rod 2 rotated in one direction (reverse rotation) and the open / close stirring blades 4 and 4 closed. The excavation hole 10 having a radius corresponding to is formed, and while excavating by the fixed stirring blade 12, the ground is excavated by the excavation claw 5 and the bit at the tip of the excavation rod 2 until the excavation rod 2 reaches the support layer 9. .

When the excavation and agitation device 1 is advanced while the ground is being dug by the opening and closing agitation blade 4 with a claw,
The excavation and agitation device 1 rotates forward and descends with the open / close agitation blades 4 and 4 opened.

When the tip of the excavating rod 2 reaches the support layer 9, the excavating rod 2 is rotated in the opposite direction (forward rotation) to open the open / close stirring blades 4, 4 as shown in (c). , (D), the solidified material is sent to the inner pipe 21 at a high pressure while pulling up the excavation rod 2, and the solidified material is injected from the injection path 41 through the injection nozzle 22.

As it is shown in (e), the open / close stirring blades 4,
The rotation of the excavation rod 2 and the injection of the solidifying material are continued until 4 rises to the target depth, and the construction is completed when the construction of the ground improvement body 11 is completed. The ground improvement body 11 is completed with a radius larger than the length of the opening / closing stirring blade 4, the excavation stirring device 1 rotates in the reverse direction, and the opening / closing stirring blades 4 and 4 are pulled out in a closed state.

[0069]

According to the first aspect of the present invention, a sleeve having an injection port communicating with the injection nozzle when the excavation rod rotates is attached to the outer circumference of the excavation rod having the injection nozzle for injecting the solidified material.
Existing structure to open and close with the rotation of the excavating rod on the outer circumference of the sleeve, and to rotatably connect the open and close stirring blade having an injection path communicating with the injection port of the sleeve when opening, and to open and close the opening and closing stirring blade with the rotation of the drilling rod. For bottom slabs of objects, it is possible to construct an improved body with a diameter larger than the diameter of the digging hole under the slab by only forming a digging hole with a size that allows the digging and stirring device to descend with the stirring blade closed. Become.

Since the open / close stirring blade is kept closed by the inner peripheral surface of the drill hole when the drill stirring device descends in the drill hole, the drill stirring device when the open / close stirring blade is closed is installed in the drill hole. It only needs to be large enough to pass, and a diameter smaller than the diameter of the ground improvement body to be constructed is sufficient. As a result, even when the number of ground improvement bodies to be constructed is large, it is not necessary to dismantle and remove the entire concrete of the bottom slab and restoration work.

When the construction target is a railway, the area of the excavation stirring device when the open / close stirring blade is in a closed state is set to a size that fits within the interval between the sleepers, so that the construction can be performed without removing the sleepers. Therefore, it is possible to construct a ground improvement body having a diameter larger than the interval between the sleepers on the ground below the railroad while keeping the railroad in use.

According to a third aspect of the present invention, in the excavation and agitation apparatus according to the first aspect, the fixed agitation blade is fixed on the outer circumference of the excavation rod above or below the open / closed agitation blade, so that the fixed agitation blade of the excavation agitation apparatus can be used when the excavation is performed. Since it is possible to stir and excavate the excavated soil in the excavation hole whose radius is the length, it is possible to secure an escape area for the excavated soil and the solidified material that are placed under high pressure, and to stir and mix the solidified material during injection. The pressure of is relaxed and the surrounding ground can be prevented from collapsing.

[Brief description of drawings]

FIG. 1 is a perspective view showing a relationship between a drilling rod and an opening / closing stirring blade of a drilling and stirring apparatus according to claim 1 or 3;

FIG. 2 (a) is a cross-sectional view showing the relationship with the excavating rod when the open / close stirring blade is opened, and (b) is a vertical cross-sectional view of (a).

3 (a) is a cross-sectional view showing the relationship with the excavating rod when the open / close stirring blade is closed, and (b) is a vertical cross-sectional view of (a).

FIG. 4 (a) is a cross-sectional view showing a configuration example of an excavation stirring device in which an opening / closing stirring blade is inclined with respect to the horizontal and connected to a sleeve, and (b) is an elevation view of (a). is there.

5A is a plan view showing the sleeve when the opening / closing stirring blade is closed, and FIG. 5B is a plan view showing the sleeve when the opening / closing stirring blade is opened.

6 (a) to 6 (c) are plan views showing an example of the shape of a lower stopper fixed to an excavating rod.

7 (a) to 7 (c) are plan views showing the relationship with the lower stopper shown in FIG. 6- (b) from the closed state to the open state of the open / close stirring blade.

8A is a perspective view showing a case where a lower stopper having an inclined upper surface is fixed to a drill rod, and FIG. 8B is a perspective view showing the relationship between the drill rod and the opening / closing stirring blade of FIG. 8A. is there.

FIG. 9 (a) is an elevational view showing a configuration example of the excavation stirring device according to claim 1 in a state where the opening / closing stirring blade is opened, and FIG. 9 (b) shows a state in which the opening / closing stirring blade is closed. FIG.

10 (a) to (e) are elevation views showing a construction procedure in the case of constructing a ground improvement body by using the excavation and agitation device shown in FIG. 9.

FIG. 11 (a) shows a state in which the opening / closing stirring blade is opened.
An elevation view showing an example of the configuration of the excavator and agitator, (b) is a side view of (a), (c) is a plan view of (a), and (d) is a state in which the open / close stirring blade is closed. It is an elevation view.

FIG. 12 (a) shows a state in which the opening / closing stirring blade is opened.
FIG. 3B is an elevational view showing another configuration example of the excavation and agitation device of FIG. 3B, and FIG.

13 is an elevational view showing a modified example of the excavating and stirring device of FIG.

14 (a) to (e) are elevation views showing a construction procedure in the case of constructing a ground improvement body by using the excavation and agitation device shown in FIG.

[Explanation of symbols]

1 ... Drilling stirring device, 2 ... Drilling rod, 21 ... Inner tube,
22 ... injection nozzle, 23 ... locked part, 3 ... sleeve,
31 …… injection port, 32 …… locking part, 33 …… plate, 34 ……
Pins 4 …… Opening / closing stirring blades, 41 …… Injection passages, 5 …… Drilling claws, 6 …… Upper stoppers, 7 …… Lower stoppers, 8 ……
Holding material, 9 ... Support layer, 10 ... Drill hole, 11 ... Ground improvement body, 12 ... Fixed stirring blade, 13 ... Stabilizer plate.

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Claims (4)

(57) [Claims] 1. A drill rod having an injection nozzle for injecting a liquid solidifying material toward the outside, and an outer periphery of the drill rod ,
It is attached so that it can rotate around the axis of the drilling rod by a fixed angle ,
Drilling when the drill rod is rotated in one direction
Rotate a fixed angle around the axis of the drilling rod in the opposite direction to the rod
And engaged with the drill rod, when its time the communicated conform to the injection nozzle, drill rod is rotated in the opposite direction
Turning the drill rod in the opposite direction to the drill rod
When the excavation rod is rotatably connected to the sleeve having an injection port that is locked and separated from the injection nozzle at that time, and is rotated in either direction.
The sleeve is rotated against the sleeve to open and the drilling rod is
When it is rotating, it rotates and closes against the sleeve,
Communicated to conform to the injection port of the sleeve at the time of the opening, at the time of closure
An excavation stirring device including an opening / closing stirring blade having an injection path separated from the injection opening of the sleeve, and the injection path of the opening / closing stirring blade matches the injection opening of the sleeve when the injection opening of the sleeve matches the injection nozzle of the drilling rod. . 2. The ground is excavated by rotating the excavating rod of the excavating and stirring apparatus according to claim 1 in a direction in which the opening / closing stirring blade is closed and closing the opening / closing stirring blade until the drilling rod reaches the support layer. After that, the excavating rod is rotated so that the opening / closing stirring blade opens, and the injection port of the sleeve is matched with the injection nozzle of the drilling rod, and the opening / closing stirring blade is opened so that the injection path is matched with the injection port of the sleeve. Inject the solidified material from the injection path of the open / close stirring blade through the injection nozzle and the injection port,
A soil improvement method for constructing a soil improvement body having a radius larger than the length of the open / close stirring blade. 3. An open / close stirring blade on the outer periphery of the drilling rod,
Alternatively, the excavating and stirring apparatus according to claim 1, wherein a fixed stirring blade is fixed to the bottom. 4. The excavation rod of the excavation and agitation device according to claim 3 is rotated in a direction in which the opening and closing agitating blade is closed, and with the opening and closing agitating blade closed, excavation having a radius corresponding to the length of the fixed agitating blade. After forming the hole, after excavating the ground until the excavation rod reaches the support layer, the excavation rod is rotated in the direction in which the opening / closing stirring blade opens, and the injection port of the sleeve is matched with the injection nozzle of the excavation rod. The opening and closing agitating blade is opened so that its injection path matches the injection port of the sleeve, and the solidification material is injected from the injection path of the opening and closing agitating blade through the injection nozzle and the injection port, and the ground improvement body has a radius larger than the length of the opening and closing agitating blade. Ground improvement method to build.