JP3706354B2 - Construction method of soil cement pile - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for constructing a soil cement pile such as a soil cement continuous wall by a column pile.
[0002]
[Prior art]
The soil cement continuous underground wall is manufactured by mixing the excavated soil and a hardened material such as cement milk when excavating with an earth auger. A pile wall is constructed.
[0003]
FIG. 10 shows a conventional excavation method for constructing such a soil cement continuous wall. In the figure, reference numeral 1 denotes an earth auger. As is well known, the tip of a screw excavation shaft 3 that is rotationally driven by a drive device 2 such as a hydraulic motor is used as an excavation head 4, and cement milk that passes through the inside of the excavation shaft 3. The hardened material can be injected from the excavation head 4. In addition, although illustration is abbreviate | omitted, the drive device 2 is suspended from the leader mast of a base machine so that raising / lowering is possible, and the excavation axis | shaft 3 can be lengthened by adding suitably. Further, the excavation shaft 3 may have a discontinuous screw. Moreover, you may utilize the excavation axis | shaft which has a stirring blade protruded horizontally instead of a screw excavation axis | shaft.
[0004]
The auger 1 is positioned (A), the excavation head 4 of the excavation shaft 3 of the auger 1 is rotated forward, and drilling is started. At that time, the hardened material 5 such as cement milk and air are taken out from the excavation head 4 and injected into the hole, and filled with a kneading material (soil cement) in which the hardened material 5 and the excavated earth and sand are mixed (B). .
[0005]
If the injection and drilling are continued to the predetermined depth while rotating forward in this way (C) (D), the pulling up is started, and the hardening material 5 is also injected at that time. This pulling is by forward / reverse rotation (E) in which forward rotation and reverse rotation are alternately repeated.
[0006]
If it is pulled up to a certain extent, excavation and agitation are performed again in the normal rotation and reverse rotation (F), and finally, the rotation is performed while reverse rotation is performed (G).
[0007]
In the continuous underground wall construction method using the pile piles of soil cement, cement milk (cement + bentonite + water) as a hardener 5 is mixed into the raw soil, and the wall body is stirred and poured. This is a construction method.
[0008]
Cement milk is injected simultaneously with excavation of the auger 1, drilled while being injected to a predetermined depth, and slightly injected even when the auger 1 is pulled out, and construction is performed while turning (forward / reverse rotation).
[0009]
By the way, industrial waste residue (mixed with soil cement and raw soil) more than the amount of cement milk injected is generated. Incidentally, in the conventional method shown in FIG. 10, industrial waste residue is generated in all steps (A) to (G). And huge costs are required for disposal. Therefore, the inventors first discharged the excavated soil in an amount corresponding to the amount of the hardened material such as cement milk previously injected as a prior excavation to the ground, and then the hardened material such as cement milk at the same time as further excavation. Inject and mix the excavated soil and hardener in the subsequent excavation, and perform the preceding excavation by a different excavation means from the subsequent excavation and the subsequent excavation by the soil cement pile generator. The invention to be summarized was filed as Japanese Patent Application No. 7-235223, and the right was obtained as Japanese Patent No. 270081.
[0010]
According to this, it is the general residual soil as the raw soil that is discharged to the ground by the preceding excavation, and this can be disposed without industrial waste. The mixing of the hardened material such as cement milk and the excavated soil is the one in which the hardened material is filled in the excavated portion, and the excavated soil is generated when the subsequent excavation is performed after the preceding excavation. Since it is used to construct a soil cement pile by mixing such hardener and excavated soil, it can be constructed without generating industrial waste residue. Further, since the hardened material such as cement milk is not thrown away with the soil, it is economically utilized without waste.
[0011]
Furthermore, by performing the excavation with excavation means different from the subsequent excavation, it is possible to reliably perform the necessary amount of soil removal in advance.
[0012]
However, if the excavation is different from the subsequent excavation, it takes time and labor to replace heavy machinery, and if the auger 1 is not single-axis but multi-axis, the excavation shape is limited to that. Therefore, it is practically impossible to perform the preceding excavation and the subsequent excavation by different excavation means.
[0013]
In the above-mentioned Patent No. 270081, the preceding excavation is the same excavation means as the subsequent excavation, and it is possible to shift from the preceding excavation to the subsequent excavation in a continuous process by performing without injecting a hardening material such as cement milk. As shown in FIG. 11, first, as shown in A and B as the first step, the auger 1 which is a soil cement pile building machine is set and the preceding excavation hole 6 is drilled. Most of this excavated soil is discharged to the ground. Further, as shown in C, the preceding excavation hole 6 is drilled to a predetermined depth. Note that this excavated soil does not have to drain 100%. And this excavated soil is general residual soil, can be treated not as industrial waste, and can be reused.
[0014]
Next, as shown in D, as shown in D, the auger 1 is pulled up by normal rotation while injecting a hardener 5 such as cement milk, and as shown in E, the excavation head 4 is pulled up to near the ground surface.
[0015]
As shown in F and G in the third step, excavation is performed by forward rotation, and the undischarged earth and sand and the hardened material 5 in the excavation hole wall are agitated. In raising H, forward rotation and reverse rotation are alternately repeated.
[0016]
In this way, the hardener 5 is excavated without injection, and after reaching a predetermined depth, the hardener 5 is injected and pulled up.
[0017]
[Problems to be solved by the invention]
In the above method, the preceding excavation hole 6 for excavating most of the excavated soil is carried out to a predetermined depth as indicated by C, and it takes a long excavation time and a large amount of the excavated soil.
[0018]
The object of the present invention is to eliminate the inconvenience of the conventional example, and as a construction method for constructing a continuous underground wall or the like by soil cement, the generation of ordinary residual soil and industrial waste residual soil can be greatly reduced, and a hardening material Therefore, the present invention provides a method for constructing a soil cement pile that requires only a small amount of injection, is inexpensive, hassle-free, and can be constructed quickly and accurately.
[0019]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, firstly, a construction site filled with a kneading material (soil cement) of a hardened material such as cement milk and excavated soil in a soil cement pile building machine which is a multi-axis auger. for that construction a predetermined length, divided into inlet leg therebelow approximately about 30% of the soil discharge section of the full-length, aligns the auger, at its periphery the auger into the soil removing section as a first step excavation Insert the soil while leaving the soil, so that the soil for the volume of the inserted excavation shaft is discharged from the ground, and then the remaining depth, which is the injection section below it, is filled with the kneading material as the second stage excavation perform stirring excavation while injecting a hardening material, it is an Abstract that stirring and then injecting a hardening material the location of the first stage drilling a third step drilling.
[0020]
Second, the agitation of the third stage excavation is performed upward from the lower end position of the first stage excavation, or the agitation of the third stage excavation is performed downward from the upper end position of the part every time the first stage excavation is performed. The gist is to do.
[0021]
Third, whether the first stage excavation is performed while discharging air or water, or from the injection amount of air and the hardener in the second stage excavation (injection amount per 1 m ^{3 of} target soil) The main point is whether it is performed by injecting a small amount of the curing material or by discharging air and water.
[0022]
According to the first aspect of the present invention, in the first stage excavation, the auger is inserted at a predetermined depth while leaving the soil around, and then, in the second stage excavation, stirring excavation is performed while injecting the hardener under the second stage excavation. It is a thing, and the soil left in the circumference becomes a plug, so that the hardened material is prevented from leaking to the ground. Even if it oozes from the auger circumference, the amount is small. Further, the hardened material poured into the soil of the second stage excavation in the state where the upper portion is closed with soil penetrates into the cracks of the hole wall by the injection pressure, and the hole wall is made dense.
[0023]
Thus, the soil when excavating with an auger is hardly discharged to the ground, and even if it is slightly discharged, it is a small amount of the auger volume, and is a general residual soil. Similarly, there is almost no ground discharge of the hardener.
[0024]
Thereafter, stirring is performed while injecting the curing material so that the kneading material fills the predetermined depth of the first stage which has not been mixed and kneaded as the third stage.
[0025]
According to the second aspect of the present invention, in addition to the above-described action, the third stage agitation is carried out without lifting the auger from the second stage excavation process to the uninjected portion of the hardened material. It can be transferred as it is.
[0026]
According to the third aspect of the present invention, since the auger is once pulled up to the ground and inserted again in order to inject and stir the uncured portion of the hardened material, it can be performed while checking the depth.
[0027]
According to the present invention of claim 4, the first stage excavation is performed while discharging air, so that the auger can be efficiently inserted into the ground, and the auger volume soil when excavating with the auger is It is possible to increase the sealing effect of discharging to the ground together with air and stacking it in a mountain shape to prevent the hardened material from leaking to the ground as the soil in the second stage excavation becomes a plug.
[0028]
The fifth to seventh aspects of the present invention are the same as the fourth aspect. In the case of claim 6, in the first stage excavation, the injection amount of the hardener is smaller than the injection amount of air and the hardener in the second stage excavation (injection amount per 1 m ^{3 of the} target soil). Thus, by injecting a small amount of the hardener, it is possible to prevent the hardener from leaking to the ground, which is economical.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1-7 is process explanatory drawing which shows one Embodiment of the construction method of the soil cement pile of this invention, FIG. 8 is a schematic diagram of this invention.
[0030]
In the figure, reference numeral 1 denotes an auger that is a soil cement pile building machine, and in the case of the present embodiment, a multi-axis auger. As is well known, the earth auger 1 has a drilling head 4 at the tip of a drilling shaft 3 with a screw or a stirring blade that is rotationally driven by a driving device 2 such as a hydraulic motor, and there are five such screw drilling shafts 3. The book is made so that a hardening material such as cement milk passing through the inside of the excavation shaft 3 can be injected from the excavation head 4. As shown in FIG. 9, the drive device 2 is suspended from the leader mast 7 of the base machine 8 so as to be lifted and lowered, and the excavation shaft 3 can be appropriately extended to be long. The excavation shaft 3 may be discontinuous.
[0031]
First, the auger 1 is aligned, and as shown in FIGS. 1 and 2, the auger is inserted at a predetermined depth (discharging section) while leaving the soil 10 in the first stage excavation process. This excavation is performed while discharging air 12 from the excavation head 4. In this case, the soil 10 having only the volume of the excavation shaft 3 to be inserted is discharged to the ground and piled on the ground. In FIG. 8, α is a predetermined length to be excavated.
[0032]
As the second stage excavation process, as shown in FIG. 3, the remaining depth below is continuously hardened so as to be filled with a kneading material (soil cement) 9 of hardened material 5 such as cement milk and excavated soil. While the material 5 is being injected, the agitation excavation is performed for a predetermined length α (the soil removal period + the injection period).
[0033]
In the second stage excavation process, the soil 10 left around the periphery serves as a plug to prevent the hardened material 5 from leaking to the ground. Although it may ooze out from the periphery of the auger 1 slightly, the amount is small. In particular, since there is soil 10 that is discharged to the ground and piled up as described above, the effect as a plug is great, and the leakage of the hardened material 5 to the ground can be prevented.
[0034]
Further, the hardened material 5 poured out into the soil of the second stage excavation in a state where the upper portion is closed with the soil 10 penetrates into cracks and the like of the hole wall by the injection pressure to make the hole wall dense.
[0035]
Further, as shown in FIG. 8B, in the portion of the soil 10, the hardener 5 injected in the second stage excavation process pushes up the lower side and penetrates to become a hardener permeation portion 11a.
[0036]
After the auger 1 reaches the depth of the full length (predetermined length α) as shown in FIG. 3, repeated stirring is performed as shown in FIG. 4, and by reverse rotation while injecting the curing material 5 as shown in FIG. 5. Pull up with stirring. The hardening material 5 to be injected at this stage also pushes up the lower side of the soil 10 and the hardening material permeating portion 11a to become a hardening material permeating portion 11b.
[0037]
Next, as shown in FIG. 6, as the third stage excavation process, the first stage excavation site, that is, the soil 10 and the hardener penetration portions 11a and 11b are stirred while the hardener 5 is injected. This agitation is turning that moves the auger 1 up and down.
[0038]
The agitation in the third stage excavation process may be performed upward from the lower end position of the location of the first stage excavation, or may be performed downward from the upper end position of the location every time the first floor excavation is performed. However, the third stage excavation can be transferred as it is without lifting the auger 1 to the ground from the second stage excavation process.
[0039]
In the latter case, the auger 1 is once pulled up to the ground and inserted again in order to inject and stir the uninjected portion of the hardening material 5.
[0040]
In the above-described process of the present invention, the amount of soil removal and the amount of hardener injected will be described. In the first stage excavation in FIG. 8 (a), the insertion of the auger 1 is about 30% of the total length α, and the remaining In the second stage excavation for a depth of 70%, about 40% of the soil 10 filling the periphery of the auger 1 of the first stage excavation is pushed up to the ground, and 60% remains.
[0041]
Furthermore, the injection of the hardener 5 in the third stage excavation after both of the hardener penetration portions 11a and 11b are formed may be small according to the amount of residual sediment in the hole.
[0042]
Thus, the general residual soil is left in the upper end portion of the excavation hole and is plugged, and the lower portion thereof is filled with the hardener 5 by excavation, and all of the excavated soil at the time of the lower excavation is mixed with the hardener 5. Because it is used as soil cement, it can be constructed with little industrial waste residue.
[0043]
In the above embodiment, the first stage excavation process is performed while discharging the air 12 from the excavation head 4. However, as the second embodiment, when water is injected alone, In the first stage excavation, when the injection amount of the hardener is smaller than the injection amount of air and the hardener in the second stage excavation (injection amount per 1 m ^{3 of the} target soil), the first stage excavation is performed as the fourth embodiment. May be performed while discharging air and water.
[0044]
In comparison with the injection amount Qt per 1 m ³ of the injection section target soil in FIGS. 1 to 7, the injection amount of water of the second embodiment, the hardening material of the third embodiment, and the injection amount of water of the fourth embodiment are all this injection. It is smaller than the quantity Qt.
[0045]
【The invention's effect】
As described above, the soil cement pile construction method according to the present invention is a construction method for constructing continuous underground walls and the like with soil cement, so that it can be constructed with almost no industrial waste residue, and the construction cost of residual soil treatment is also low. In order to reduce the cost, it is possible to perform construction quickly, with high accuracy and without any hassle.
[0046]
Further, since the hardened material such as cement milk is not thrown away with the soil, it is economically utilized without waste.
[Brief description of the drawings]
FIG. 1 is a first process explanatory view showing one embodiment of a method for constructing a soil cement pile according to the present invention.
FIG. 2 is a second process explanatory view showing an embodiment of a method for constructing a soil cement pile according to the present invention.
FIG. 3 is an explanatory diagram of a third step showing an embodiment of a method for constructing a soil cement pile according to the present invention.
FIG. 4 is a fourth process explanatory view showing an embodiment of a method for constructing a soil cement pile according to the present invention.
FIG. 5 is a fifth process explanatory view showing one embodiment of a method for constructing a soil cement pile according to the present invention.
FIG. 6 is an explanatory diagram of a sixth step showing one embodiment of a method for constructing a soil cement pile according to the present invention.
FIG. 7 is a seventh process explanatory view showing one embodiment of a method for constructing a soil cement pile according to the present invention.
FIG. 8 is a schematic diagram of a method for constructing a soil cement pile according to the present invention.
FIG. 9 is a side view of a multi-axis auger used.
FIG. 10 is an explanatory diagram showing a conventional example.
FIG. 11 is an explanatory diagram showing another conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Auger 2 ... Drive apparatus 3 ... Excavation shaft 4 ... Excavation head 5 ... Hardening material 6 ... Prior excavation hole 7 ... Leader mast 8 ... Base machine 9 ... Kneading material 10 ... Soil 11a, 11b ... Hardening material penetration | invasion part 12 ... Air

Claims (7)

With a soil cement pile construction machine that is a multi-axis auger, to construct a predetermined length of construction site filled with a kneading material (soil cement) of hardened material such as cement milk and excavated soil,
Divide into approximately 30% of the entire length of the soil removal section and the injection section below it.
Align the auger,
As a first stage excavation, the auger is inserted into the soil excavation section while leaving the soil around it, and the soil for the volume of the excavation shaft to be inserted discharges the ground,
Next, as the second stage excavation, stirring excavation is performed while injecting the hardener so that the remaining depth of the lower injection section is filled with the kneading material,
After that, as a third stage excavation, the site of the first stage excavation is agitated while injecting a hardener, and a method for constructing a soil cement pile. The method for constructing a soil cement pile according to claim 1, wherein the stirring of the third stage excavation is performed upward from the lower end position of the location of the first stage excavation. The method for constructing a soil cement pile according to claim 1, wherein the agitation of the third stage excavation is performed downward from the upper end position of the location every time the first stage excavation is performed.   The construction method of the soil cement pile according to any one of claims 1 to 3, wherein the first stage excavation is performed while discharging air.   The soil cement pile construction method according to any one of claims 1 to 3, wherein the first stage excavation is performed while discharging water. 4. The first stage excavation injects a hardener injection amount less than the injection amount of air and the hardener in the second stage excavation (injection amount per 1 m ^{3 of} target soil). Construction method of the soil cement pile described.   The method for constructing a soil cement pile according to any one of claims 1 to 3, wherein the first stage excavation is performed while discharging air and water.

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