JP3920974B2 - Earth auger excavator and construction method of deep underground column wall in collapsible gravel layer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, as a type of retaining wall construction method, using a ground auger excavator to mix a cement-based hardener into the in-situ soil to create a columnar soil pile, and then a columnar column into which a core material is inserted The present invention relates to a technique for constructing a deep columnar continuous underground wall in a collapsible gravel layer by using an underground continuous wall method, a so-called in-situ agitated pile-type columnar continuous column wall method.
[0002]
[Prior art]
Conventionally, in the case of building a columnar continuous underground wall (hereinafter referred to as a “continuous wall”) in a collapsible gravel layer by the in situ soil mixing pile columnar column type underground continuous wall method, the following procedure is performed. It was. That is, first, in the earth auger excavator 1 ′ as shown in FIG. 9, the single-shaft auger 4 ′ of (a) is used, and after drilling while injecting poorly mixed CB liquid to the design depth of the soil pile, In the same manner, a poorly blended CB solution is injected and stirred while pulling out the shaft auger 4 '(preceding drilling). Next, the single-shaft auger 4 'is replaced with the triaxial auger 3' shown in FIG. 5B, and the pre-drilled portion is drilled to the same depth as the previous drill hole (main drilling). At this time, compressed air is discharged from the discharge hole at the tip of the triaxial auger 3 ′ in order to remove the already excavated soil from the portion so that the bit 31b at the tip of the triaxial auger 3 ′ always contacts the unexcavated surface. While drilling or discharging cement milk, which is a cement hardening agent, from another discharge hole different from the discharge hole, drilling is performed. Then, after drilling to a predetermined depth, the triaxial auger 3 ′ is rotated in the direction opposite to that at the time of drilling, and in the same manner as described above, the triaxial auger 3 ′ is discharged while discharging compressed air and cement milk as a cement hardening agent. The in-situ soil and the cement milk are stirred by the stirring blade 31d ′ while pulling up, and a columnar soil mortar (soil pile) is formed (injection stirring). Finally, before the soil mortar is hardened, an H-shaped steel as a core material is erected there (core material erection). In the preceding drilling step and the main drilling step, the next hole is constructed by overlapping the previously constructed hole in order to make the water stop performance of the continuous wall complete. A continuous wall is constructed by repeating these four steps of preceding drilling → main drilling → injection stirring → core material erection.
[0003]
[Problems to be solved by the invention]
However, although it is possible to construct a continuous wall having a depth of about 40 m or less according to the conventional method as described above, the construction of a so-called large-depth continuous wall having a depth of 40 m or more is as follows. It was more difficult.
[0004]
(1) In this drilling process, a large amount of existing excavated gravel will stick to the triaxial auger 3 'without being moved upward (jamming), and fine excavated soil such as fine sand and silt Since it sticks to the triaxial auger 3 ′ without being moved upward (squeezing / capping phenomenon), the drilling efficiency is extremely lowered, and further drilling becomes impossible.
[0005]
(2) In the agitating and agitating step, a large amount of already excavated gravel settles toward the bottom of the hole without being discharged, so that it is impossible to build a core material thereafter.
[0006]
(3) In this drilling step, the compressed air discharged from the discharge hole at the tip of the triaxial auger 3 'is not smoothly discharged, so that the pressure at the hole bottom at the tip of the bit 31b becomes excessive, and more It becomes impossible to drill holes.
[0007]
(4) In this drilling process, if the operator continues to work significantly exceeding the rated output of the earth auger excavator 1 'without being aware of the cases of (1) to (3) above, An overload is applied to the speed reducer and motor of the excavator 1 ', causing a failure.
[0008]
(5) Because of the large depth, the bending rigidity of the triaxial auger 3 ′ in this drilling process is insufficient, and it is difficult to drill vertically with the triaxial auger 3 ′. I can't hold it.
[0009]
Therefore, in order to solve the above-described problems, the present invention provides a construction method for preventing the excessive pressure at the bottom of a drilled hole, an earth auger excavator, in the construction of a deep wall in a collapsible gravel layer, the settling delay of existing excavated gravel and existing excavated soil, The purpose is to provide an earth auger excavator that enables smooth wall construction by preventing overloading and ensuring vertical accuracy of drilling holes, and a method for constructing deep wall walls in collapsible gravel layers. To do.
[0010]
[Means for Solving the Problems]
  That is, the invention according to claim 1 is a continuous auger provided with moving blades over the entire length of the rod, the moving blade diameter at the upper end being substantially equal to the design diameter of the soil pile, and the lower moving blade diameter.Is onMoving blade diameterLarger diameterIt is an earth auger excavator characterized by mounting an auger that is a single axis or a multi-axis.
[0011]
Thus, according to the earth auger excavator equipped with the auger formed so that the moving blade diameter is increased at least downward, the lower the auger, the greater the force to move the already excavated gravel and the already excavated soil upward. Therefore, the sedimentation of the already excavated gravel and the already excavated soil can be delayed, and the jamming of the already excavated gravel into the auger, the filling and capping phenomenon of the already excavated soil can be prevented, and the core material can be built.
[0012]
  The invention according to claim 2 is the upper moving blade diameterBigger thanAn earth auger excavator characterized in that a single-axis or multi-axis auger having air vent holes drilled in a lower moving blade having a blade diameter is mounted.
[0013]
According to the earth auger excavator configured in this way, the compressed air discharged from the discharge hole at the tip of the auger at the time of main drilling can smoothly escape to the ground direction, so that excessive pressure at the bottom of the hole can be prevented. It will be possible to drill holes smoothly.
[0014]
  According to a third aspect of the present invention, in the first aspect of the invention, the upper moving blade diameterBigger thanAn earth auger excavator characterized by mounting a single-axis or multi-axis auger having air vent holes drilled in the lower moving blade having a blade diameter.
[0015]
By using an earth auger excavator equipped with an auger that combines the function of delaying sedimentation of already excavated gravel and soil and the function of preventing excessive pressure at the bottom of the hole, smoother drilling can be achieved. It becomes possible.
[0018]
According to a fifth aspect of the present invention, in the invention according to any one of the first to third aspects, the detection means for detecting the rotational load of the auger, and the display means for displaying the detection result in the detection means. And an earth auger excavator.
[0019]
In the earth auger excavator having such a configuration, the detection means detects that the auger is overloaded, and the result is displayed on the display means. When an operator performs an operation such as reducing the output as appropriate, an overload applied to the speed reducer and the motor can be prevented in advance, which contributes to a smooth continuous wall construction.
Also,An earth auger equipped with an auger that combines the function of delaying sedimentation of already excavated gravel and soil and the function of preventing excessive pressure at the bottom of the hole, and further adding an overload prevention function to an earth auger excavator equipped with the auger By using an auger excavator, even smoother drilling becomes possible.
[0020]
  Claim5The invention described in 1 is a method for constructing a deep underground column-type continuous underground wall in a collapsible gravel layer, characterized by comprising the following first to third steps.
  (1) Soil pile construction position with single axis auger to design depthHardens to the extent that it can prevent collapse of the drilled groundDrilling holes while injecting CB liquid and pulling up the single-axis auger into the original soilHardens to the extent that it can prevent collapse of the drilled ground1st process which inject | pours and stirs CB liquid.
  (2) The position constructed in the first step is a multi-axis auger type.4Drilling while injecting cement-based hardener to the design depth by the earth auger excavator according to any one of the above, injecting cement-based hardener into the original soil while stirring the multi-axis auger, stirring Second step of forming a soil pile.
  (3) A third step of inserting a core material into the soil pile formed in the second step before hardening.
[0021]
According to the above method, in order to use the earth auger excavator according to any one of claims 1 to 5, in the main drilling step of the continuous wall construction method in the conventional collapsible gravel layer, By taking advantage of the earth auger excavator, it is possible to smoothly construct a deep wall in the collapsible gravel layer.
[0022]
  Claim6The invention described in claim 15In the described invention,
The next step 0 is performed before the first step.5It is a construction method of the deep underground column type continuous underground wall in the collapsible gravel layer described.
  (0) Soil pile construction position with a single axis auger is drilled to a certain depth shallower than the design depth, and the single axis auger is pulled up to the original soilHardens to the extent that it can prevent collapse of the drilled groundThe 0th process which inject | pours and stirs CB liquid.
[0023]
Thus, by performing the so-called pre-drilling of the 0th step before the preceding drilling of the 1st step, the amount of sedimentation of the already excavated gravel and the already excavated soil at the time of drilling can be reduced and one drilling can be performed. The depth can be shortened and the vertical accuracy of the hole can be increased.
[0024]
  Claim7The invention described in claim 15Or claim6In the described invention, the cement-based curing agent is 1 m of target soil.^ThreeA deep column system in a collapsible gravel layer, characterized in that it is cement milk with a blend of 25 (kg) to 35 (kg) per bentonite and a water cement ratio of 130 (%) to 230 (%) It is a construction method of continuous underground wall.
[0025]
In this way, by increasing the viscosity and specific gravity of the cement-based hardener, it becomes possible to delay the sedimentation of the already excavated gravel and the already excavated soil after the formation of the soil pile, and the core material can be easily built.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is used for the same element and the overlapping description shall be abbreviate | omitted.
[0027]
1. Earth auger excavator
(1) Overall configuration
FIG. 1 is a side view showing an embodiment of an earth auger excavator according to the present invention. FIG. 1A is an earth auger excavator equipped with a single-shaft auger. The earth auger excavator 1 shown here is a three-point crawler auger machine 2 that includes a single-shaft auger 4 having a special shape and a speed reducer 5 of the earth auger excavator 1 for detecting the rotational load of the single-shaft auger 4. The tachometer 6 and the ammeter 7 are connected to the detection means, and the alarm buzzer 8 is a display means for displaying the detection result of the ammeter 7. FIG. 2B shows a triaxial auger 3 that can be exchanged for the single axis auger 4 in FIG. Hereinafter, the configuration of each part will be described in detail.
[0028]
(2) Configuration of each part
(1) Three-axis auger 3
FIG. 2 is an enlarged side view of the triaxial auger 3 shown in FIG. The triaxial auger 3 shown in the figure is formed by vertically connecting a lower first joint auger 31 and an upper second joint auger 32 by a vertical connection portion (not shown). The first joint auger 31 and the second joint auger 32 are horizontally coupled by a horizontal coupling device 33 at two upper and lower portions of the three-axis auger.
[0029]
As for the first-node auger 31, each auger is formed at the base 31a and a lower end of the rod 31a, and the rod 31a rotates about its axis to cut the hole bottom at the cutting edge. 31b, a moving blade 31c that is intermittently provided around the rod 31a and plays a role of pushing up the already excavated gravel and the like from below, and a predetermined position of the rod 31a. Etc. at the original position. Note that an air vent hole 31e is formed in the moving blade 31c.
[0030]
Here, as shown in the figure, the diameter of the moving blade 31 c of the lower first-node auger 31 is larger than the diameter of the moving blade 32 c of the upper second-node auger 32. The diameter of the moving blade 32c is the same as that of the conventional art, and specifically, is approximately equal to the design diameter of the soil pile. When the three-axis auger 3 formed with the moving blades 31c and 32c is rotated in this way, the already excavated gravel around the first-node auger 31 is pushed upward from below with a stronger force than before, An effect of delaying sedimentation of already excavated gravel at the time of drilling will be exhibited. Here, the diameter of the moving blades in the same node auger is made equal and the diameter of the lower moving blade is larger than the diameter of the upper moving blade, but the present invention is not limited to this, and the same node auger is used. The diameter of the moving wing may be continuously changed to form a so-called frustoconical outer shape that expands downward. However, in this case, care should be taken that the diameter of the moving blade at the upper end portion of the triaxial auger 3 is substantially equal to the design diameter of the soil pile. Of course, the lower end portion of the triaxial auger 3 is configured so that the moving blades 31c provided in the rods 31a do not interfere with each other.
[0031]
In addition, an air vent hole 31e is formed in the moving blade 31c. This is provided so that the compressed air discharged from the discharge hole at the tip of the bit 31b can be smoothly discharged in the ground direction during the main drilling. Here, since the diameter of the upper moving wing 32c is smaller than the diameter of the lower moving wing 31c, air can smoothly escape to the ground without providing an air vent hole in the upper moving wing 32c. Air vent holes may be formed in both the blades 31c and 32c. The position, shape, etc. of the air vent hole 31e are not limited to those shown in FIG.
[0032]
The triaxial auger 3 is configured as described above. However, the triaxial auger 3 in the present invention is not limited to the present embodiment. For example, not only two but also three or more nodes are vertically connected. Further, the auger is not limited to the three-axis type, and may be two axes or four axes or more. The shapes, positions, and the like of the moving blade 31c and the stirring blade 31d are not limited to those shown in the drawing, and may be determined as appropriate in consideration of necessary functions and mutual relationships.
[0033]
▲ 2 ▼ Single axis auger 4
As shown in FIG. 1A, the single-shaft auger 4 is simply a single-shaft type of the three-shaft auger 3. As will be described later, the three-point crawler auger machine 2 in the first drilling process and the preceding drilling process. Used by attaching to.
[0034]
(3) Tachometer 6, ammeter 7 (detection means), alarm buzzer 8 (display means)
As shown in FIG. 1, the speed reducer 5 of the earth auger excavator 1 is connected to a tachometer 6 and an ammeter 7 which are detection means for detecting the rotational load of the auger. More specifically, a tachometer 6 that measures the number of revolutions of the speed reducer 5 and converts it into an electrical signal is connected to the speed reducer 5, and a current that grasps the electrical signal converted by the tachometer 6 as a current value. A total 7 is connected to the tachometer 6. The driver's seat of the earth auger excavator 1 is provided with an alarm buzzer 8 as display means for displaying the detection result of the detection means. Specifically, when the current value measured by the ammeter 7 exceeds a preset constant value continuously for a preset time, the output is reduced to the worker at the driver's seat of the earth auger excavator 1. An alarm buzzer 8 is provided so as to emit a warning sound to the effect.
[0035]
According to such an earth auger excavator 1, for example, when a large amount of excavated gravel has stuck to the triaxial auger 3 in the present drilling process, the reduction in the drilling efficiency is reduced. As a result, it is possible to prevent a situation in which the operation of the motor significantly exceeds the rated output of the motor without being noticed by the increase in the output of the motor that rotates the motor. This can be prevented and contributes to smooth drilling.
[0036]
In the present embodiment, the tachometer 6 is connected to the alarm buzzer 8 via the ammeter 7. However, as another example, for example, only the tachometer 6 is connected to the speed reducer 5, and the number of revolutions measured there is calculated. The alarm buzzer 8 may be transmitted to the alarm buzzer 8 using a mechanical means, or the ammeter 7 is connected to the motor, and the current value measured here is managed and transmitted to the alarm buzzer 8. An aspect of operating this may be used. Moreover, the installation position of the alarm buzzer 8 is not limited to the inside of the driver's seat, but may be installed, for example, in a work indoor installed outside the earth auger excavator 1. Further, the display means other than the alarm buzzer 8 may be, for example, a pen recorder or a combination of the alarm buzzer 8 and the pen recorder. In short, the earth auger excavator 1 may be configured to include a detection unit that detects the rotational load of the auger by some method and a display unit that displays the detection result of the detection unit by any method. The combination with is also arbitrary.
[0037]
2. Construction method of deep wall in collapsible gravel layer
3 to 7 are process diagrams for explaining a method for constructing a deep deep wall in a collapsible gravel layer according to the present invention. Hereinafter, it demonstrates along the order of each process.
[0038]
(1) 0th step (first drilling)
FIG. 3 is a diagram for explaining a 0th step of the method for constructing a deep wall with a collapsible gravel layer according to the present invention. That is, as shown in FIG. 1 (a), first, the earth auger excavator 1 equipped with the single-shaft auger 4 shown in FIG. 1 (a) is installed at a predetermined position and drilled to a certain depth. The drilling depth at this time is sufficient to be shallower than the design depth of the soil pile pile to be constructed. Next, as shown in FIG. 5B, the poor blended CB liquid is poured into the original soil while stirring the single-shaft auger 4 and stirred. This poor blended CB liquid is hardly hardened unlike cement milk described later, and the state where the stirring pile C of the in-situ soil and the poor blended CB liquid is formed after the injection and stirring is completed is shown in FIG. (C). In this way, in the construction of a deep wall with a collapsible gravel layer, the agitation pile C is formed in the upper layer portion of the ground to reduce the sedimentation amount of the already excavated gravel and the already excavated soil at the time of drilling. The process for shortening the depth of the drilling holes to increase the vertical accuracy of the subsequent drilling is this 0th process (first drilling). Here, the single-shaft auger 4 described above is used as an auger. However, since the stirring pile C formed in this step is shallow, an auger similar to the conventional auger may be used.
[0039]
(2) First step (preceding drilling)
Subsequent to the 0th step (first drilling) shown in FIG. 3, the first step (preceding drilling) is performed as shown in FIGS. First, as shown in FIG. 4 (a), a stirring pile C was formed in the 0th step (first drilling) using the earth auger excavator 1 equipped with the single-shaft auger 4 shown in FIG. 1 (a). The hole is drilled while injecting the poor blended CB liquid. Then, further drilling is performed beyond the depth of the stirring pile C, and drilling is performed to the design depth of the soil pile of the continuous wall to be constructed. At this time, since the agitation pile C is formed in the upper layer of the ground in the previous 0th step (preliminary drilling), the upper layer of the ground collapses, and jamming occurs due to the sedimentation of the excavated gravel and the like. No further drilling is possible. And the state which this drilling was completed is shown in FIG.4 (b). The single-axis auger 4 at this time is preferably the one shown in FIG. 1A from the viewpoint of drilling ability, but this is not necessarily limited to this. In the case of a single shaft, unlike the case of a multi-shaft, the torque applied to one auger is large, so that there is little possibility of falling into a state in which drilling is impossible due to sedimentation of already excavated gravel and the like.
[0040]
Next, as shown in FIG. 5 (a), the single pile auger 4 is pulled up, and the poorly mixed CB solution is poured into the in-situ soil and stirred, so that the stirring pile reaches the design depth of the soil pile to be constructed. C is formed. That is, the stirring pile C formed in the previous 0th step (preliminary drilling) is formed over the entire design depth of the soil pile of the continuous wall to be constructed as well as the upper layer portion of the ground. As a result, in the subsequent second step (main drilling), drilling can be performed smoothly even when the torque applied to one auger is small as a multi-axis type, which contributes to improvement of drilling accuracy. FIG. 5B shows a state in which the stirring pile C at the completion of this process is formed.
[0041]
(3) Second step (main drilling)
Next, the second step (main drilling) shown in FIGS. 6 and 7 will be described. First, as shown in FIG. 6A, a stirring pile C was formed in the first step (preceding drilling) using the earth auger excavator 1 equipped with the triaxial auger 3 shown in FIG. 1B. A place is drilled while injecting a cement hardening agent to the same depth as the stirring pile C. At this time, in the previous first step (preceding drilling), since the stirring pile C is formed over the entire design depth of the soil pile of the continuous wall to be constructed, the torque applied to one auger as a triaxial type is Even when the hole is small, the hole wall does not collapse or the occurrence of jamming or the like due to sedimentation of already excavated gravel or the like does not make further drilling impossible. Further, the three-axis auger 3 used at this time has a moving blade of the first section larger in diameter than that of the second section and more, and has a function of delaying the settling of already excavated gravel or the like. However, the moving blades of the three-axis auger 3 are provided with air vent holes to prevent excessive pressure at the bottom of the holes, or although not shown, the earth auger excavator 1 has detection means and display means. Since it is provided and has a function of preventing overload applied to the earth auger excavator 1, smooth drilling is possible. And the state which this drilling was completed is shown in FIG.6 (b).
[0042]
Next, as shown in FIG. 7A, a cement pile hardener is poured into the in-situ soil while the triaxial auger 3 is pulled up and stirred to form a soil pile S. The cement-based hardener at this time has a function of delaying the settlement of the already excavated gravel and the already excavated soil, and in order to smoothly perform the subsequent third step (building the core material), the viscosity and specific gravity are higher than usual. The formulation is increased. Specifically, for example, target soil 1m^ThreeCement milk (water cement ratio 180 (%)), which is a mixture of 250 (kg) cement, 30 (kg) bentonite, and 450 (kg) water, is used. In addition, in this invention, not only this mixing | blending but the conventional normal mixing | blending (target soil 1m^Three1 m of target soil than per cement (250 kg), bentonite 15 (kg), water cement ratio 230 (%) to 280 (%)^ThreeBy increasing the bentonite by 10 (kg) to 20 (kg) and reducing the water-cement ratio by 50 (%) to 100 (%),^ThreePercent bentonite may be cement milk having a blend of 25 (kg) to 35 (kg) and a water cement ratio of 130 (%) to 230 (%). FIG. 7B shows a state in which the soil pile S has been formed when this process is completed.
[0043]
(3) Third step (built-in core material)
As shown in FIG. 8, the third step is a step of building an H-shaped steel H as a core material as a reinforcing material of the soil pile S, and needs to be completed before the soil pile S is hardened. Specifically, as shown in FIG. 8 (a), the H-section steel H is suspended and built by a crane or the like, but the length of each H-section steel H is about 10 m depending on transportation circumstances. Therefore, in the construction of deep multi-story walls to which the present invention is applied, they are performed while reinforcing them with a joint. FIG. 8B shows a state in which the building of the H-section steel H is completed in this way. In addition, as a core material, a sheet pile or the like may be used.
[0044]
(4) Other
By repeating the above-described steps, a deep wall can be smoothly constructed in the collapsible gravel layer. As described above, the method for constructing a deep wall in the collapsible gravel layer according to the present invention is to prevent sedimentation of already excavated gravel and already excavated soil, to prevent excessive pressure at the bottom of the borehole, and to prevent overload applied to the earth auger excavator. By ensuring the vertical accuracy of the drilling holes, smooth continuous wall construction can be achieved, and various design cases can be dealt with by making appropriate design changes in accordance with this purpose.
[0045]
【The invention's effect】
As described above, the present invention has the following remarkable effects. That is, according to the first aspect of the present invention, the lower the auger, the greater the force for moving the already excavated gravel and the already excavated soil upward, so that the sedimentation of the already excavated gravel and the already excavated soil is delayed, This prevents jamming of existing excavated gravel, clogging / capping of existing excavated soil, and enables smooth wall construction.
[0046]
According to the second aspect of the present invention, the compressed air discharged from the discharge hole at the tip of the auger can be smoothly discharged in the ground direction during the main drilling. Make wall construction possible.
[0047]
According to invention of Claim 3, it becomes an earth auger excavator equipped with the auger which has both the sedimentation delay function of the already excavated gravel and the already excavated soil, and the pressure excess prevention function of the bottom of the hole. Drilling is possible.
[0048]
According to the invention described in claim 4, since the detection means detects that the auger is overloaded and the result is displayed by the display means, the worker of the earth auger excavator who notices the display. However, by performing operations such as reducing the output as appropriate, it is possible to prevent overloads applied to the speed reducer and the motor, thereby contributing to smooth continuous wall construction.
[0049]
  AlsoAn auger that combines the function of delaying settling of already excavated gravel and soil and the function of preventing excessive pressure at the bottom of the hole was installed, and an overload prevention function was added to the earth auger excavator equipped with the auger. Since it becomes an earth auger excavator, even smoother drilling becomes possible.
[0050]
  Claim5According to the invention described in claim 1, in the drilling step of the conventional method for building a continuous wall in a collapsible gravel layer, the claims 1 to4Since the earth auger excavator as described in any one of the above is used, it is possible to smoothly construct a deep wall with a collapsible gravel layer by taking advantage of the earth auger excavator.
[0051]
  Claim6According to the invention described in the above, it is possible to reduce the sedimentation amount of the already excavated gravel and the already excavated soil at the time of drilling, to reduce the depth of one drilling hole, and to increase the vertical accuracy of the drilling hole. This contributes to the smooth wall construction.
[0052]
  Claim7According to the invention described in (2), it becomes possible to delay the sedimentation of the already excavated gravel and the already excavated soil after the formation of the soil pile, and the construction of the core material is facilitated, which contributes to the smooth continuous wall construction. .
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of an earth auger excavator according to the present invention, in which (a) is an earth auger excavator equipped with a single-shaft auger, and (b) is a single-shaft in (a). It is a triaxial auger that can be exchanged with an auger.
FIG. 2 is a partially enlarged side view of the triaxial auger shown in FIG. 1 (b).
FIG. 3 is a process diagram showing an embodiment of a method for constructing a deep underground column wall in a collapsible gravel layer according to the present invention, showing the 0th step thereof.
FIG. 4 is a process diagram illustrating a process subsequent to FIG. 3, and illustrating a first process.
FIG. 5 is a process diagram showing a process following the process shown in FIG. 4, and showing a first process.
FIG. 6 is a process diagram showing a process following the process shown in FIG. 5, and showing a second process.
7 is a process diagram showing a process following the process shown in FIG. 6, and showing a second process. FIG.
8 is a process diagram showing a process continued from FIG. 7, and showing a third process. FIG.
FIG. 9 is a side view showing a conventional earth auger excavator.
[Explanation of symbols]
1 Earth auger excavator
1 ’Earth auger excavator
2 Three-point crawler auger machine
2a motor
3 Triaxial auger
3 'triaxial auger
4 Single axis auger
4 'single axis auger
5 Reducer
6 Tachometer (detection means)
7 Ammeter (detection means)
8 Alarm buzzer (display means)
31 Section 1 Ogre
31a Rod
31b bit
31c Mobile wing
31d stirring blade
31d 'stirring blade
31e Air vent hole
32 Section 2 Ogre
32a rod
32c Mobile wing
32d stirring blade
33 Horizontal coupling device
C Stirring pile
H H-section steel (core material)
S soil pile

Claims (7)

A continuous auger having a moving blade over the entire length of the rod, approximately equal movement blade diameter of the upper end is designed diameter of Soirupairu, and the auger is greater diameter than the moving blade diameter of the upper side is moved wings diameter of the lower An earth auger excavator having single or multi-axis mounting. An earth auger excavator characterized in that an auger having air vent holes drilled on a lower moving blade having a larger blade diameter than an upper moving blade diameter is mounted on a single shaft or multiple shafts. 2. The earth auger excavator according to claim 1, wherein a single-axis or multi-axis auger provided with air vent holes is attached to the lower moving blade having a larger blade diameter than the upper moving blade diameter.   The earth auger excavator according to any one of claims 1 to 3, further comprising: a detection unit that detects a rotational load of the auger; and a display unit that displays a detection result of the detection unit. . A method for constructing a deep underground column-type continuous underground wall in a collapsible gravel layer, comprising the following first to third steps.
(1) Soil pile construction position with a single-axis auger is drilled while injecting CB liquid that hardens to the design depth to prevent collapse of the drilled ground. A first step of injecting and stirring a CB solution that cures to such an extent that collapse of the resin can be suppressed.
(2) A cement-based hardener is injected to the design depth by the earth auger excavator according to any one of claims 1 to 4, wherein the position constructed in the first step is a multi-axis auger type. A second step of forming a soil pile by drilling and injecting a cement-based hardener into the in-situ soil while pulling up the multi-axis auger and stirring.
(3) A third step of inserting a core material into the soil pile formed in the second step before hardening. 6. The method for constructing a deep columnar continuous underground wall in a collapsible gravel layer according to claim 5, wherein the next step 0 is performed before the first step.
(0) The soil pile construction position is drilled to a certain depth shallower than the design depth with a single-shaft auger, and a CB solution that hardens to the extent that the collapse of the drilled ground can be suppressed while pulling up the single-shaft auger. Step 0 of stirring. The cement-based hardener is cement milk having a blend of 25 (kg) to 35 (kg) bentonite and 130 (%) to 230 (%) water cement ratio per 1 m ³ of the target soil. The construction method of the deep underground column type continuous underground wall in the collapsible gravel layer of Claim 5 or Claim 6.

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