JP2576046B2 - Method of forming cured soil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a cured soil in a soil by mixing earth and sand of the original ground with a consolidation liquid.

[0002]

2. Description of the Related Art Conventionally, there has been known a method of mixing soil and sand of an original ground with a consolidation liquid to form a cured soil in the ground. However, when the soil and the consolidation liquid of the original ground are mixed with the consolidation liquid to form a soil hardened body in the ground, a mixture of the soil and the consolidation liquid of the original ground and the consolidation liquid such as cement milk overflows on the ground, and Mixtures of ground overfill with consolidation liquids such as cement milk contaminate the working environment on the ground, and this mixture must be disposed of as industrial waste, which is expensive. Further, since the consolidation liquid such as cement milk is discarded, the amount of the consolidation liquid used increases, and this also causes an increase in cost.

To solve the above problems, Japanese Patent Laid-Open Publication No. 4-49314 has been proposed. In the conventional example disclosed in Japanese Patent Application Laid-Open No. 4-49314,
Prior to the injection of cement milk, the target ground was drilled to a certain depth from the ground surface to a certain depth, and the earth and sand on the ground surface inside the drill hole was discharged and removed in an amount corresponding to the amount of cement milk to be injected. The drilled pilot hole was further excavated to a predetermined depth by an excavator, and then a predetermined amount of cement milk was injected from the excavator tip and kneaded, and it was confirmed that the mixture of excavated soil and cement milk had risen to the ground surface. By confirming this, the amount of cement milk to be injected is controlled.

[0004]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Laid-Open No. 4-49 is disclosed.
In the conventional example disclosed in Japanese Patent Publication No. 314 (hereinafter simply referred to as a conventional example), a prepared hole formed by anhydrous drilling is excavated and excavated, and a hollow formed by the anhydrous drilling is formed. The drilling shaft of the excavator is inserted into the hole, and the lower part of the hollow hole that has become a cavity is further excavated to a predetermined depth by the excavator to form a drilling hole. There is a possibility that the ground around the pilot hole may collapse due to the vibration or the like given by the excavator. In addition, when preparing the preparation hole and the excavation step below the preparation hole separately as a setup for the construction at the site, only the preparation hole is dug one after another first, and then a plurality of pre-drilled preparation holes In order to put the drilling shaft of the excavator in order to drill below the hollow hole,
The time during which the pre-drilled pilot hole is left in a hollow state is prolonged, and at this point, the peripheral wall of the pilot hole left in a hollow state may collapse due to various vibrations generated at the construction site. When the ground around the pilot hole collapses in this way, not only can the soil hardened body of a predetermined shape not be formed, but also, as in the conventional example, the mixture of the excavated soil and the cement milk rises to the ground surface, and the cement milk is injected. In the method of controlling the amount, the ratio of cement milk in the mixture of cement milk and earth and sand is relatively reduced due to the collapse of the ground around the pilot hole.

In the above conventional example, since the mixture of excavated soil and cement milk rises to the ground surface, the amount of cement milk used is controlled. It is necessary to leave the cavity until the point where the lower part of the pilot hole is excavated.For this reason, if the amount of cement milk is to be controlled by the conventional method, the hollow pilot hole is necessary. In addition, the fact that the ground around the hollow hole is apt to collapse is a problem that the above-described conventional method of controlling the injection amount of cement milk itself is necessarily incorporated.

[0006] In the field of underground construction, it has been generally practiced to fill the excavation hole with a liquid material for preventing the surrounding ground from collapsing in order to prevent the ground from collapsing. Have been done. However, in order to prevent ground collapse by filling a liquid material for preventing ground collapse in a conventional drilling hole, bentonite is used as a liquid material for preventing peripheral ground collapse, and bentonite is used in a hole. Is filled to prevent collapse of the ground around the hole, and at the time of forming the column in the hole, the bentonite is discharged from the hole while the cement-based liquid material that is the raw material of the column is injected and replaced in the hole This is a so-called replacement method. Therefore, if it is supposed to apply a conventionally known technique for preventing the collapse of the surrounding ground of the surrounding ground in order to prevent the collapse of the surrounding ground around the pilot hole that was previously excavated in the above-described conventional example, It is conceivable to fill the prepared hole with bentonite to prevent the ground around the prepared hole from collapsing. However, in this case, in the subsequent step, the drilling is performed below the pilot hole and excavated to a predetermined depth, filled with cement milk and replaced with bentonite, so that bentonite eventually overflows to the ground. Contrary to the idea of the above-mentioned conventional example that the mud does not overflow on the ground, after all, the technique of preventing the collapse of the surrounding ground by the replacement method known as the technique of preventing the surrounding ground forms the hollow hole. It cannot be applied to the conventional example.

[0007] Further, in the above-mentioned conventional example, it is described that it is possible to excavate while drilling a cement hole into the lower part of the pilot hole after the drilling of the pilot hole is anhydrous. When excavating while injecting, the excavator's excavation axis's excavation descent speed is not constant depending on the condition of the ground,
Especially when there is obstacle such as hard ground or stone, the excavation speed of excavation axis is slow, and when cement milk is injected at the time of excavation descent by excavation axis, cement milk per unit excavation distance of excavation hole Injection amount increases,
When the drilling axis has not yet reached the target depth, the mixture of cement milk and drilling earth may rise to a predetermined ground level. However, in the conventional example, the management of the injection amount of the cement milk to be injected as described above is performed by confirming that the mixture of the cement milk and the excavated soil rises to a preset ground surface level. Therefore, the injection of the cement milk is stopped at this point, and thereafter, the excavation is performed by the excavation axis without injecting the cement milk to a predetermined depth. That is, in the conventional example, since the injection amount of the cement milk is controlled when the mixture of the cement milk and the excavated earth reaches a predetermined ground surface level, the cement milk is controlled according to the state of the ground. The depth of the excavation by the excavator at the time when the injection of the gas is stopped is varied. For example, as shown in FIG. 8A, the leading hole 1 is formed, and then the excavation is performed below the leading hole 1 in a hollow state. When the cement milk is discharged and mixed while stirring, for example, the injection of the cement milk is stopped at the depth of FIG. Considering the case where the injection of the cement milk is stopped at the depth of (), (the injection amount A of the cement milk in the case of FIG. 8B)
> (Injection amount B of cement milk in FIG. 8 (c)). That is, (the volume of the preceding holes) A = - a (Distance volume of drilling axis of an H ₁ minute), also, B = (volume prior hole)
− (The volume of the excavation axis for a distance H ₂ ), where H ₁
<Because it is H _2, in practice the injection of cement milk B
Is different depending on the difference in the descending speed of the excavating shaft 4 ', and there is a problem that the inflow amount B of cement milk cannot be controlled to be constant. It is not practical to excavate while injecting cement milk. In FIG. 8, reference numeral 1 denotes a preceding hole, and 4 'denotes an excavation axis. In FIG. 8, H ₃ is a target excavation depth.

[0008] On the other hand, in the case where the cement milk is injected at the time of lifting after the excavator has reached the predetermined depth, the mixture of the cement milk and the excavated earth and sand is set at the predetermined ground surface level during the lifting in the same manner as described above. When it rises, the cement milk injection is stopped, and thereafter, the cement milk is pulled up without being injected. In this case, when the pulling speed is constant, the level of the lower end of the excavation axis at the time when the injection of the cement milk is stopped can always be kept at a constant position. It is possible to control the injection amount of cement milk by the conventional method only when the pulling speed is constant, and it is possible to change the pulling speed or arbitrarily set the drilling axis to improve stirring and mixing. When raising and lowering, the level of the lower end of the excavation axis at the time of stopping the injection of the cement milk is not constant, and therefore, for the same reason as the above-described case of injecting the cement milk during insertion, It is not possible to control the amount of milk injection constantly.

As described above, in the conventional example in which the injection of the cement milk is controlled when the mixture of the cement milk and the excavated earth and sand rises to the preset ground surface level as in the conventional example, the excavation shaft is actually used. When excavating by inserting into the specified depth, the cement milk is not discharged, and only when the drilling shaft is pulled up at a constant speed without raising and lowering the drilling shaft while ejecting the cement milk from the drilling shaft at the time of lifting. It is impossible to control the amount of cement milk injected.

However, the fact that the lifting speed of the drilling shaft is constant and that the drilling shaft cannot be moved up and down at the time of injection leads to insufficient stirring and mixing of the cement milk and the drilling earth and sand. In other words, depending on the properties of excavated earth and sand, for example, in the case of stirring and mixing of cohesive soil and cement milk, and in the case of stirring and mixing of sandy soil and cement milk, cohesive soil is much more agitated than sandy soil. It is necessary to lengthen the mixing time, and if they are the same, the desired stirring and mixing cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and is intended to prevent muddy soil in which excavated earth and sand and a consolidation liquid are mixed from overflowing to the ground (or to allow a small amount to overflow). ) In this way, it is not necessary to dispose of mud as industrial waste, or only a very small amount of treatment is required. In order to improve the working environment, consolidation is used while preventing the ground around the pilot hole from collapsing. Liquid management is easy, and
The first purpose is to prevent the vertical moving speed and the vertical repetitive movement of the rotary kneading shaft from affecting the management of the consolidation liquid, and to use the consolidation used while preventing the ground around the pilot hole from collapsing. The second object is to make it possible to easily and accurately manage the liquid, and to make it possible to easily control the liquid used for consolidation while preventing collapse of the ground around the pilot hole, and at the lower side of the drilling hole. The third object is to prevent the shortage of the consolidation liquid, and to control all or most of the consolidation liquid to be used by controlling the amount of the consolidation liquid previously placed in the lower hole. Excavation and agitation and mixing of the ground below the pilot hole are performed effectively even though the consolidation liquid is not spouted from the rotary kneading shaft or is only ejected supplementarily during excavation and agitation mixing of the lower ground of The fourth object is to That the continuous underground wall sintered body is continuous can construction with extremely reduced disposal volume of ground mud is to a fifth object of.

[0012]

In order to solve the above-mentioned problems of the prior art and achieve the object of the present invention, a method for forming a cured soil according to the present invention comprises the steps of: In a method of forming a soil cured product in which a soil cured product is formed in the ground by mixing, a pilot hole 1 having a diameter substantially equal to the diameter of the soil cured product to be formed and having a shallower depth than the soil cured product to be formed. Is formed in the ground 2 by anhydrous drilling, and the excavated earth and sand generated by the drilling of the pilot hole 1 is discharged and removed to the ground, and a consolidation liquid 3 is poured into the pilot hole 1, and then the ground 2a below the pilot hole 1 , And the excavated earth and sand and the consolidation liquid 3 are stirred and mixed.

When excavating the ground 2a below the pilot hole 1, it is also preferable to excavate without discharging the consolidation liquid from the rotary kneading shaft 4 used for excavation. When excavating the ground 2a below the pilot hole 1, it is also preferable to excavate while ejecting the consolidation liquid 3 from the rotary kneading shaft 4 used for excavation. It is also preferable to mix the excavated earth and sand and the consolidation liquid 3 while injecting air 5 when excavating the ground 2a below the pilot hole 1.

It is also preferable that a plurality of rotary kneading shafts 4 are arranged in a multi-axis, and that the rotation trajectories of adjacent rotary kneading shafts 4 partially overlap in plan view.

[0015]

According to the method of the present invention as described above, a pilot hole 1 having a diameter substantially equal to the diameter of the soil hardened material to be formed and having a shallower depth than the soil hardened material to be formed is formed in the ground 2 in an anhydrous manner. The excavated earth and sand formed by the drilling of the pilot hole 1 is discharged and removed to the ground, and the consolidation liquid 3 is poured into the pilot hole 1. By stirring and mixing the excavated soil and the consolidation liquid 3, the amount of the consolidation liquid 3 corresponding to (or substantially corresponding to) the design amount used for stirring and mixing with the excavated earth and sand is previously prepared in the pilot hole 1. Before the excavation of the lower ground 2a, the consolidation liquid 3 to be used can be easily managed. That is, since the diameter and depth of the prepared hole 1 are known in advance,
The volume of the pilot hole 1 is known in advance, and based on this, it is easily determined how far the consolidation liquid 3 to be used should be filled in the pilot hole 1 (for example, to the upper end of the pilot hole 1). It is required to add the liquid 3 or the level of the liquid 3 from the upper end). Therefore, the consolidation liquid 3 to be used can be easily managed. And the consolidation liquid 3 used in advance in this way
Is inserted into the pilot hole 1 in advance, so that the lower ground 2a of the pilot hole 1
In the excavation, mixing and stirring of excavated earth and sand with the consolidation liquid 3, the vertical moving speed of the rotary kneading shaft 4 and the reciprocating up and down reciprocating movements impose restrictions on the management of the consolidation liquid 3. I will not receive it. In addition, the ground surrounding the pilot hole 1 is prevented from collapsing by directly using a consolidation liquid that is a material for forming a soil hardened body by stirring and mixing with excavated earth and sand in the lower ground 2 a of the pilot hole 1. Can be done.

When excavating the ground 2a below the pilot hole 1, a consolidation liquid 3 is supplied from a rotary kneading shaft 4 used for excavation.
In the case of excavating without excavating, the consolidation liquid 3 to be used can be managed only by controlling the consolidation liquid 3 put in the prepared hole 1, and the management of the consolidation liquid 3 can be more accurately performed. You can do it. In the case of excavating the ground 2 below the pilot hole 1 while excavating the consolidation liquid 3 from the rotary kneading shaft 4 used for excavation, the excavation hole 1 containing the consolidation liquid 3 is used. When the lower ground 2a is excavated and the excavated earth and sand and the consolidation liquid are stirred and mixed, the consolidation liquid 3 can be prevented from becoming insufficient even at a lower position of the lower ground 2a.

In the case where the amount of the consolidating liquid used is controlled by previously putting an amount (or almost the corresponding amount) corresponding to the consolidating liquid to be used into the prepared hole 1, the ground below the prepared hole 1 In excavation and stirring and mixing of 2a, during excavation and stirring and mixing of the ground below the pilot hole, the consolidation liquid is not spouted from the rotary kneading shaft 4 or is only spouted out auxiliaryly. Excavation of the lower ground 2a of the pilot hole 1 is more difficult to excavate than excavating while injecting a consolidation liquid at the time of excavation, and is also more agitated and mixed than what is agitated and mixed while injecting a consolidation liquid. Although the efficiency is low, the excavated earth and sand and the consolidation liquid 3 are stirred and mixed while injecting the air 5 when excavating the lower ground 2 a of the prepared hole 1.
When excavating the ground 2a below the pilot hole 1, the excavation can be performed with the air 5 and the excavated earth and sand and the consolidation liquid 3 can be effectively agitated and mixed by stirring with the air 5, and at this time, the rotary kneading shaft is used. The moving speed of the air 4 in the vertical direction is not affected (or hardly affected) by the management of the consolidation liquid 3, and the amount of the air 5 to be blown varies depending on the state of the ground (that is, the rotation according to the state of the ground). If the moving speed of the kneading shaft 4 in the vertical direction is different, the ejection amount of the air 5 at that position is different), and the excavation of the ground 2a below the pilot hole 1 is not affected by the management of the consolidation liquid 3 and according to the state of the ground. And the stirring and mixing efficiency can be facilitated.

In the case where the rotary kneading shaft 4 is a multi-axis in which a plurality of rotary kneading shafts 4 are arranged and the rotation locus of the adjacent rotary kneading shafts 4 partially overlaps in plan view, the continuous underground wall in which the soil-solidified body is continuous is provided. It is not necessary to dispose of the mud on the ground, or the disposal amount can be extremely reduced.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments shown in the accompanying drawings. 1 to 3 show one embodiment of the present invention. First, the pilot hole 1 is formed in the ground 2 by a drilling device such as a screw auger 6. The pilot hole 1 has a diameter substantially equal to the diameter of the soil cured body to be formed and has a depth smaller than that of the soil cured body to be formed. When forming the pilot hole 1, the drill hole is formed by anhydrous drilling, and the excavated earth and sand is discharged and removed to the ground when the pilot hole 1 is excavated by an excavator such as the screw auger 6. The excavation depth of the pilot hole 1 may be such that the volume of the pilot hole 1 is a volume corresponding to the amount of the consolidation liquid 3 used for forming the soil hardened body, or used for forming the soil hardened body. It may be larger than the volume that can contain the used amount of the consolidation liquid 3, or in the case of construction where a shallow trench is dug first and the pilot hole 1 is dug at the bottom of the trench,
Since it is permissible that a part of the consolidation liquid 3 flows into the trench, the volume may be slightly smaller than the amount of the consolidation liquid 3 used for forming the cured soil body in this case.

The excavated soil generated by the anhydrous drilling of the pilot hole 1 is discharged to the ground as shown in FIG. 1 or FIG. 2, but the earth and sand 8 discharged to the ground is not mixed with liquid. Even if it can be treated and treated as sediment for backfill at the site or transported outside the site, it is treated as soil and sand, so the processing cost is lower than that of industrial waste such as mud. Is much cheaper.

In the prepared hole 1 formed by the anhydrous drilling, a cementing liquid 3 such as cement milk or a cement-based liquid containing cement milk as a main component and other materials is introduced. In this case, the drill hole 1 is excavated by the screw auger 6 in the order shown in FIGS. 1A to 1E to remove the excavated earth and sand, and the screw auger 6 is completely pulled out from the pilot hole 1. As shown in FIG. 1, the consolidation liquid 3 is put into the lower hole 1 from the lower end of the screw auger 6 or the consolidation liquid 3 is put into the lower hole 1 by another means for injecting the consolidation liquid 3.
(F). In this case, the injection can be performed while directly checking the injection state of the consolidation liquid 3 into the lower hole 1 by eyes. As another method, FIG.
In the order of (a) to (c), the screw auger 6 is excavated to a predetermined depth while rotating the screw auger 6, and when the screw auger 6 is lifted while rotating, the excavated earth and sand is placed below the screw auger 6. When the screw auger 6 is pulled up as shown in FIG. 2D, the consolidation liquid 3 is formed from the lower end of the screw auger 6 at a position below the lower end of the screw auger 6 as shown in FIG. 2 (e) by sequentially filling the consolidation liquid 3 in the gap.

Here, the amount of the consolidating liquid 3 to be put into the pilot hole 1 is an amount corresponding to an amount necessary for forming a cured soil body formed by using the pilot hole 1, or an amount substantially corresponding thereto. It is something to put. After the pilot hole 1 is formed and the consolidation liquid 3 is poured into the hole 1 as described above, the rotary kneading shaft 4 of the excavator is immediately formed.
The process may be shifted to the step of excavating the ground 2a below the pilot hole 1 (using a screw auger 6 different from the screw auger 6 for forming the pilot hole 1), but only the pilot hole 1 is formed one after another,
The consolidation liquid 3 may be added thereto, and after forming a certain number of prepared holes 1, the process may be shifted to the step of excavating the ground 2a below the prepared hole 1 sequentially with the rotary kneading shaft 4 of the excavator.

In any case, the pilot hole 1 is formed by anhydrous drilling, the excavated earth and sand generated by the drilling of the pilot hole 1 is discharged and removed to the ground, and the consolidating liquid 3 is introduced into the hollow pilot hole 1. 3 (a) in a state in which the surrounding ground in the pilot hole 1 is prevented by inserting
1 to 3, the rotary kneading shaft 4 is inserted into the pilot hole 1 and the ground 2a below the pilot hole 1 is excavated to a predetermined depth. Stirring means 7
Thus, the excavated earth and sand in the lower ground 2a is mixed with the consolidation liquid 3 which is put into the lower hole 1 and serves to prevent the ground around the lower hole 1 from collapsing. Therefore, the liquid put in the pilot hole 1 serves to prevent the ground around the pilot hole 1 from collapsing and also serves as a consolidation liquid for stirring and mixing with the excavated earth and sand in the ground 2 a below the pilot hole 1. As a result, the liquid 3 and the excavated sediment do not overflow with the liquid or the mud mainly composed of the liquid, which plays the role of preventing the collapse, even if it overflows. Can be formed in the hole. Note that FIG.
In the case of raising the rotary kneading shaft 4 as shown in (d), the excavated earth and sand and the consolidation liquid 3 may be agitated and mixed by raising the rotary kneading shaft 4 while rotating. In this way, the ground is filled with the mixture 20 in which the excavated earth and sand and the consolidation liquid 3 are stirred and mixed, and the columnar body 9 is formed.
(See (e)), and the columnar body 9 is cured to form a cured soil body. The columnar body 9 can form an underground wall by continuously forming a large number of the columnar bodies 9 so as to partially overlap with the adjacent columnar bodies 9 in plan view. Here, the rotary kneading shaft 4 used in the embodiment has stirring means 7 and a bit 10 is provided at the lower end.

In the embodiment shown in FIG. 3, when the ground 2 a below the pilot hole 1 in which the consolidation liquid 3 is filled is excavated by the rotary kneading shaft 4, the consolidation liquid 3 is discharged from the rotary kneading shaft 4. It shows an example of excavating without digging. In this embodiment, when excavating the ground 2a below the pilot hole 1, the consolidation liquid 3
Therefore, only the consolidation liquid 3 previously placed in the pilot hole 1 is used as the consolidation liquid 3 for forming the cured soil body. Can be managed only by managing the consolidation liquid 3 put in the pilot hole 1, and the consolidation liquid 3 can be easily and reliably managed.

In the embodiment of FIG. 4, when the ground 2a below the pilot hole 1 in which the consolidation liquid 3 is filled is excavated by the rotary kneading shaft 4, the consolidation liquid 3 2 shows an example in which excavation and agitation and mixing are performed while discharging. In this embodiment, the lower ground 2a of the pilot hole 1 in which the consolidating liquid 3 is filled.
When excavating and mixing the excavated earth and sand with the consolidation liquid 3,
The lower position of the lower ground 2a is lower than that of the upper
In such a case, the consolidation liquid 3 can be prevented from running short even at a position below the lower ground 2a.
And then excavate the lower ground 2a of the pilot hole 1 to form a hardened soil by stirring and mixing. The excavated earth and sand and the consolidating liquid 3 can be stirred and mixed over the entire length in the vertical direction. is there. In this case, it can be said that the consolidation liquid 3 is discharged from the rotary kneading shaft 4 when excavating the lower ground 2a and stirring and mixing. In this case, the consolidation liquid 3 discharged from the rotary kneading shaft 4 is auxiliary. Most of the consolidating liquid 3 to be used for forming the cured soil is mostly the consolidating liquid 3 previously placed in the pilot hole 1. Therefore, even if there is a difference in the discharge amount of the consolidation liquid 3 discharged from the rotary kneading shaft 4 due to the difference in the excavating speed of the rotary kneading shaft 4 depending on the state of the ground 2, The difference in the discharge amount due to the difference in the excavation speed is small in view of the total used amount. Therefore, most of the consolidation liquid 3 to be used can be controlled by the amount of the consolidation liquid 3 previously put in the pilot hole 1. Therefore, the mixture of excavated earth and sand and the consolidation liquid 3 may temporarily overflow. Even Tsu,
The amount is very small as compared with the conventional case, and even if it is treated as industrial waste, a very small amount is sufficient.

FIGS. 5 and 6 show still another embodiment of the present invention. In this embodiment, there is shown an example in which air 5 is blown from the rotary kneading shaft 4 when excavating the ground 2a below the pilot hole 1 and stirring and mixing the excavated earth and sand with the consolidation liquid 3. is there. In this case, when the air 5 is blown downward from the lower end of the rotary kneading shaft 4, it serves to excavate the lower ground 2a and more effectively mixes the excavated earth and sand with the consolidation liquid 3 by stirring. In particular, after the air 5 jetted from the lower end contributes to the excavation and stirring and mixing at the lower end portion of the rotary kneading shaft 4, the air 5 rises as bubbles upward, so that the excavated sediment is raised and each part in the vertical direction is raised. In this case, it contributes to the stirring and mixing of the consolidation liquid 3 and the excavated earth and sand. Therefore, in a state where the consolidation liquid 3 is previously placed in the pilot hole 1, the lower ground 2 a of the pilot hole 1 is excavated, and the excavated soil and the consolidation liquid 3 previously placed in the pilot hole 1 are stirred and mixed. In the method of the present invention, in order to manage the consolidation liquid 3 mainly by the amount of the consolidation liquid 3 put in the pilot hole 1, when excavating the lower ground 2a, the consolidation liquid 3 is used. The lower ground 2a is harder to excavate because it is not discharged or is only discharged as auxiliary if it is discharged.
When excavation is facilitated without affecting the management of the consolidation liquid, and the consolidation liquid 3 is mainly controlled by the amount of the consolidation liquid 3 previously put in the pilot hole 1, the consolidation liquid 3 3 and the excavated sediment tend to enrich the excavated sediment on the lower side.
By jetting, the excavated earth and sand below can be effectively transferred to be stirred and mixed effectively, and the soil hardened body in which the excavated earth and sand and the consolidation liquid 3 are well stirred and mixed in the vertical direction can be removed. It can be formed. Of course, the air 5 may also be ejected from a portion other than the lower end of the rotary kneading shaft 4 to contribute to the stirring and mixing, and the air 5 is ejected from a plurality of locations other than the lower end and the lower end of the rotary kneading shaft 4. This may be done. Figure 5 shows the lower ground 2
FIG. 6 shows a case where only air 5 is blown out when excavating a with the rotary kneading shaft 4, and FIG. 2 shows an embodiment showing an example in which is injected.

In the embodiment shown in FIG.
Shows an example of using a multi-axis excavator in which a plurality of drills are arranged.
Here, in the multi-spindle excavator, the rotation trajectories of the adjacent rotary kneading shafts 4 partially overlap in plan view. Specifically, the rotation trajectory of the bit 10 and the stirring means 7 provided on the rotary kneading shaft 4 partially overlaps in plan view with the rotation trajectory of the bit 10 and the stirring means 7 provided on the adjacent rotary kneading shaft 4. Is used. FIG. 7 shows an example in the case where the above-described multi-axis excavator is used. In this embodiment, as shown in FIG. 7A, a plurality of pilot holes 1 communicating with each other are formed in advance, and excavated earth and sand are discharged and removed to the ground.
As shown in FIG. 7 (b), the consolidation liquid 3 is put therein, and then, as shown in FIG. 7 (c), the plurality of rotary kneading shafts 4 of the multi-screw excavator are inserted into the plurality of pilot holes 1, The lower ground 2a of the plurality of pilot holes 1 is excavated to a predetermined depth, and the excavated earth and sand and the consolidation liquid 3 are stirred and mixed.
As shown in (e), a continuous underground wall 30 in which a plurality of columnar soil compacts are continuous can be formed. In this case, there are a case where the consolidation liquid 3 is not discharged from the rotary kneading shaft 4 during excavation of the lower ground 2a by the rotary kneading shaft 4 and a case where the consolidation liquid 3 is discharged auxiliary. When the consolidating liquid 3 is discharged in an auxiliary manner, whether the liquid is discharged from all of the plurality of rotary kneading shafts 4 or whether it is discharged from an arbitrary rotary kneading shaft 4 is determined as follows.
It can be set according to the condition of the ground at the site. Also,
When excavating the lower ground 2a, the excavation may be performed while the air 5 is ejected, and the excavated earth and sand and the consolidation liquid 3 may be mixed with stirring. Also in this case, there is a case where the consolidation liquid 3 is not discharged from the rotary kneading shaft 4 during the excavation of the lower ground 2a by the rotary kneading shaft 4, and a case where the consolidation liquid 3 is discharged auxiliary. Further, the rotary kneading shaft 4 for discharging the air 5 and the consolidating liquid 3 can be arbitrarily set according to the state of the ground.

By the way, in any of the above embodiments of the present invention, the amount of the consolidation liquid 3 (or almost the corresponding amount) determined by the design used for the soil cured body using the plurality of pilot holes 1 is used.
Is put into the pilot hole 1 before excavation and stirring and mixing by the rotary kneading shaft 4 in the subsequent process, so that all or most of the consolidating liquid 3 to be used is put into the pilot hole 1 in advance. 3 can be managed. That is, it is possible to control the consolidation liquid to be used by pouring the consolidation liquid up to the upper end of the pilot hole 1 or by pouring the consolidation liquid from the pilot hole 1 to an arbitrary lower position. When the pilot holes 1 are formed at regular intervals at the bottom of the trench, the consolidating liquid 3 is poured up to the upper end of the pilot hole 1,
Alternatively, the consolidating liquid 3 is introduced from the prepared hole 1 to an arbitrary lower position, or the consolidating liquid 3 is set to an arbitrary depth of the trench.
Can be managed by putting in). This can be controlled, for example, by using a ruler or by visually checking how far the consolidation liquid 3 has entered the prepared hole 1. Therefore, excavation and stirring and mixing by the rotary kneading shaft 4 in the subsequent process are not affected by the management of the consolidation liquid 3. For this reason, the vertical moving speed of the rotary kneading shaft 4 when excavating and stirring and mixing with the rotary kneading shaft 4 in the subsequent process can be freely selected according to the state of the ground 2, and the vertical movement of the rotary kneading shaft 4 The stirring and mixing can be freely performed while repeating the steps many times, and the excavation and the stirring and mixing can be favorably performed according to the state of the ground. In this case, most of the consolidation liquid 3 to be used is controlled by the amount of the consolidation liquid put in the pilot hole 1 even when the consolidation liquid 3 is discharged auxiliary when the rotary kneading shaft 4 is excavated. As a result, the consolidation liquid 3 can be easily managed, and the difference in the amount of the consolidation liquid 3 discharged due to the difference in the vertical moving speed of the rotary kneading shaft depending on the state of the ground 2 is as follows. , A small percentage of the total consolidation liquid volume,
Therefore, even if some matter is discharged as mud, the amount can be reduced.

In any of the above-described embodiments, it is a matter of course that H steel or another stress material may be inserted into the soil hardened body as required.

[0030]

According to the first aspect of the present invention, as described above, the diameter of the soil hardened body to be formed is substantially equal to that of the soil hardened body to be formed, and the depth of the soil hardened body to be formed is smaller than that of the soil hardened body to be formed. A shallow pilot hole is formed in the ground by anhydrous drilling, and the excavated earth and sand generated by the drilling of the pilot hole is discharged to the ground and removed, a consolidation liquid is poured into the pilot hole, and then the ground below the pilot hole is excavated. The excavated earth and sand and the consolidation liquid are stirred and mixed.
It is possible to control all or most of the consolidation liquid used in the formation of the soil cured product by the amount of the consolidation liquid put in advance in the prepared hole. Regardless of the moving speed in the direction, it can be managed simply and reliably. Since the amount of the consolidating liquid used in this manner can be easily and reliably managed regardless of the vertical moving speed of the rotary kneading shaft, the rotary kneading shaft excavates the ground below the pilot hole, mixes and mixes the ground. The vertical movement speed of the rotary kneading shaft can be arbitrarily changed according to the conditions, and excavation and stirring and mixing can be performed according to the state of the ground. In addition, since all or most of the consolidation liquid used for forming the cured soil body can be controlled by the amount of the consolidation liquid previously placed in the lower hole, the consolidation liquid or the consolidation liquid and the excavated soil are not used. It is possible to prevent the mixed mud from overflowing to the ground, or even if it overflows, in a small amount, and it is not necessary to dispose of it as industrial waste, or if it is necessary to do so, only a small amount of treatment is required and it is used. The cost can be reduced because there is no waste of the consolidation liquid and there is no need to treat it as industrial waste, or even if it is treated in a very small amount. In addition, the consolidation liquid, which is placed in the pilot hole in advance and serves to prevent the ground around the pilot hole from collapsing, is used as it is as a material for forming a cured soil body by stirring and mixing it with the excavated earth and sand below the pilot hole. So
The desired soil cured product can be formed without overflowing a large amount of the liquid for preventing collapse or mud mixed with the liquid.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, when excavating the ground below the pilot hole, the solidification from the rotary kneading shaft used for excavation. Since the excavation is carried out without the use of the solution, the consolidation liquid used in the pilot hole can be managed only by controlling the consolidation liquid used.
The consolidation liquid can be more easily and accurately managed.

The third aspect of the present invention has the following effects in addition to the effects of the first aspect of the present invention. That is, the consolidation liquid is put in the pilot hole in advance, and most of the consolidation liquid to be used is controlled by the amount of the consolidation liquid put in the pilot hole in advance. In the case of excavation and stirring and mixing, the consolidation liquid tends to be insufficient at the position below the lower ground, but when excavating the ground below the pilot hole, the consolidation liquid is supplied from the rotary kneading shaft used for excavation. Excavation while blasting prevents soil shortage even in the lower part of the lower ground, preventing soil shortage. It is one that can form a body.

The invention according to claim 4 has the following effect in addition to the effect of the invention according to claim 1 or claim 2 or claim 3. I have. That is, the consolidation liquid is put in the pilot hole in advance, and all or most of the consolidation liquid to be used is controlled by the amount of the consolidation liquid put in the pilot hole in advance. When excavating the ground and mixing with stirring, it is difficult to excavate the lower ground inevitably, and the consolidation liquid tends to be insufficient at the position below the lower ground, and the stirring and mixing efficiency tends to deteriorate, Since air is injected when excavating the ground, excavation is facilitated by air, and the excavated earth and sand and the consolidation liquid can be effectively agitated and mixed by stirring with air. The moving speed of the kneading shaft in the vertical direction is not affected (or hardly affected) by the management of the consolidation liquid, and the amount of air jet varies depending on the state of the ground (that is, the rotational kneading depends on the state of the ground). The vertical movement speed of the axis And the amount of air blown out at that position is different). As a result, excavation of the ground below the pilot hole is facilitated according to the state of the ground without being affected by the management of the consolidation liquid, and The agitating and mixing can be satisfactorily performed, and when the air rises, the excavated sediment below is moved upward by the air and is agitated and mixed. Can be favorably stirred and mixed.

According to the fifth aspect of the present invention, in addition to the effects of the second aspect, the third aspect or the fourth aspect, in addition to the multi-rotation kneading shaft, a plurality of rotary kneading shafts are arranged. Because the rotating locus of the adjacent rotary kneading shaft partially overlaps in plan view, it is not necessary to dispose of the continuous underground wall where the solidified soil is continuous, The construction can be performed with extremely small amount of water.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a step of forming a pilot hole and pouring a consolidation liquid into the pilot hole in one embodiment of the present invention.

FIG. 2 is an explanatory view of another embodiment showing a step of forming a pilot hole and introducing a consolidation liquid into the pilot hole according to the first embodiment.

FIG. 3 is an explanatory diagram showing excavation and stirring and mixing processes of the ground below the pilot hole of the above.

FIG. 4 is an explanatory view showing a state in which a consolidation liquid is spouted and assisted in the excavation and stirring and mixing processes of the ground below the pilot hole.

FIG. 5 is an explanatory view showing a state in which the air is blown out to perform the construction.

FIG. 6 is an explanatory view showing an example in which the above-mentioned auxiliary jetting of the consolidation liquid and the jetting of air are both used.

FIG. 7 is an explanatory view showing a series of steps showing an example of a case of performing construction using a multi-axis excavator.

FIG. 8 is an explanatory diagram for explaining a problem of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Preparatory hole 2 Ground 2a Lower ground 3 Consolidation liquid 4 Rotary kneading shaft 5 Air

Claims (5)

(57) [Claims] 1. A method for forming a soil cured product in which soil is mixed with consolidation liquid of an original ground to form a soil cured product in the ground, wherein the diameter of the soil cured product is approximately equal to the diameter of the soil cured product to be formed. In addition, a drill hole shallower than the soil hardened body to be formed is formed in the ground by anhydrous drilling, and excavated earth and sand generated by drilling of the drill hole is discharged to the ground and removed. And then, excavating the ground below the pilot hole and stirring and mixing the excavated earth and sand with the consolidation liquid. 2. The method for forming a hardened soil body according to claim 1, wherein, when excavating the ground below the prepared hole, excavation is performed without discharging a consolidation liquid from a rotary kneading shaft used for excavation. . 3. The method for forming a cured soil body according to claim 1, wherein when excavating the ground below the pilot hole, excavation is performed while jetting a consolidation liquid from a rotary kneading shaft used for excavation. 4. The method according to claim 1, wherein the excavated earth and sand and the consolidation liquid are stirred and mixed while injecting air when excavating the ground below the prepared hole. The method for forming a cured soil according to any one of the above. 5. A multi-axis in which a plurality of rotary kneading axes are arranged,
5. The method for forming a cured soil body according to claim 2, wherein the rotation trajectories of adjacent rotary kneading shafts partially overlap in plan view.