JP3727017B2 - 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]
The conventional excavation method for constructing the soil cement continuous wall concerning FIG. 4 is shown. 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. The excavation shaft 3 may be discontinuous.
[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]
The continuous underground wall construction method using the pile piles of soil cement injects cement milk (cement + bentonite + water) as hardener 5 into the raw soil, and injects the amount of m ² × 60%. This is a method of building a wall body by stirring.
[0008]
For example, to build a unit wall that is 50cm wide, 20m deep and 1m long,
0.5 × 2.0 × 1 × 0.5 = 6m ³
Therefore, it is necessary to inject about 6 m ³ of cement milk. Cement milk of 6 m ³ was injected at the same time as drilling auger 1, and drilling while injecting up to a predetermined depth, and also injected slightly upon withdrawal of the auger 1, which construction while turning (forward and reverse) .
[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. 4, 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. 5, first, as shown in A and B as the first step, the auger 1 that 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 purpose of the present invention is to eliminate the inconvenience of the conventional example, and as a construction method for constructing continuous underground walls with soil cement, it can be constructed with almost no industrial waste residual soil, and the construction cost of residual soil treatment is also low. Therefore, it is an object of the present invention to provide a method for constructing a soil cement pile that can be constructed quickly and accurately without trouble.
[0019]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention firstly aligns the auger, performs a depth of about 40% of the predetermined length by air digging, and then mixes the remaining depth of about 60%. Stir excavation while injecting the hardener so that it is filled with the kneading material, and then pulling up the stirrer by reverse rotation while injecting the hardener so that the kneading material fills a depth of about several percent of the predetermined length Then, when drilling a predetermined depth again, the kneading material is filled with the remaining depth of the remaining several tens of the predetermined length, and the predetermined length is drilled again by forward rotation while injecting the hardening material. The relationship between the excavation part of the preceding soil unit and the excavation part of the succeeding soil unit in the drilling hole in the auger is appropriately spaced so that the excavation part of the preceding soil unit is located between the excavation part of the subsequent soil unit. Drilling more than one It is to some degree of solidification [0.102N / mm ² or more (※ Nt = 9.80665)] gist to carry out drilling of the trailing soil unit drilling portion after waiting for the preceding soil unit drilling portion.
[0020]
Second, in the case of stirring and pulling up by reverse rotation while injecting the hardening material, the kneading material is filled to a depth of about 20% of the predetermined length, and again injecting the hardening material when drilling the predetermined depth. The gist of the kneading material in the forward rotation is to fill a depth of about 20% of the predetermined length.
[0021]
According to the present invention of claim 1 and claim 2, it is general residual soil as raw soil that is first excavated to the ground by excavation at a depth of about 40%, and this is not industrial waste. Can be disposed of. Next, filling with the kneading material is performed in three stages of about 60%, about 20%, and about 20%, and each of them is stirred and excavated while injecting the hardened material, stirred and pulled up by reverse rotation, and again predetermined As deep drilling, excavated soil uses what is generated when excavating after general residual soil is discharged, and a soil cement pile body is constructed by sufficiently careful mixing of such excavated soil and hardener. Since there is no waste in continuous work and the hardened material such as cement milk is not thrown away with the soil, it is economically utilized. In particular, after excavation of general residual soil, stirring excavation is performed with the same excavator further injecting hardener with this drilling hole, and continuity can be ensured without raising the excavator, and it is necessary Excavated soil and hardened material can be secured.
[0022]
Furthermore, in addition to the above action, after waiting for a certain degree of solidification [0.102 N / mm ² or more (* Nt = 9.80665)] of the preceding soil unit excavation part, the subsequent soil unit excavation part is excavated. When constructing the trailing soil unit, if the auger is pulled down, the inconvenience that the upper unexcavated earth and sand is mixed into the left and right preceding soil units and a high quality soil wall cannot be formed can be solved.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a process explanatory view showing an embodiment of a method for constructing a soil cement pile according to the present invention.
[0024]
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. 3, the driving 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 extended to be long. The excavation shaft 3 may be discontinuous.
[0025]
First, the auger 1 is aligned (a). α is a predetermined length to be excavated.
[0026]
As a first step, a depth of about 40% of the predetermined length α is performed by air digging by air discharge in the auger 1 (b). In this case, most of the excavated soil is discharged to the ground. This excavated soil is general residual soil and can be treated and reused not as industrial waste.
[0027]
As the second step, as shown in (c), the remaining depth of about 60% is continuously filled with the kneading material (soil cement) 9 of the hardened material 5 such as cement milk and the excavated soil. Stirring excavation with a predetermined length α is performed while injecting the hardener 5.
[0028]
Thereafter, as shown in (d), stirring and pulling up by reverse rotation is performed while injecting the curing material 5 so that the kneading material 9 fills about 20% of the total length (predetermined length α).
[0029]
As shown in (e), when the predetermined depth is drilled again, the kneading material 9 is rotated forward while injecting the curing material 5 so as to fill a depth of about 20% of the total length (predetermined length α). The predetermined length α is drilled again, and then the auger 1 is pulled up as shown in (f). During this pulling up, air discharge is stopped.
[0030]
In the above-described embodiment, the ratio of filling the kneading material 9 in (d) and the filling ratio of the kneading material 9 in (e) are about 20% of the total length (predetermined length α). However, the ratio may be relatively different, for example, about 10% and about 30%.
[0031]
Thus, the hardened material 5 is filled in the place where the general residual soil is discharged, and all the excavated soil when excavating is mixed with this hardened material 5 and used as soil cement, so almost all industrial waste residual soil is generated. Construction can be done without
[0032]
The soil cement continuous underground wall, when excavated by the auger 1, stirs the excavated soil and the hardened material 5 such as cement milk to produce a pile body of soil cement in the ground. It is made by constructing row pile walls. The drilling holes in the auger 1 as shown in FIG. 2 include a leading soil unit excavation part A, a trailing soil unit excavation part B between a preceding soil unit excavation part A and a trailing soil unit excavation part B. A plurality of holes are drilled with a certain interval.
[0033]
More specifically, in the preceding soil unit excavation part A and the subsequent soil unit excavation part B, one excavation part of the excavation shaft 3 on the left and right outer sides of the auger 1 or a part of one excavation overlap. And drilling.
[0034]
In this case, after waiting for this leading soil unit excavation part A to solidify to some extent [0.102 N / mm ² or more (* Nt = 9.80665)], excavation of the trailing soil unit excavation part B is performed. And By doing this, when constructing the trailing soil unit, if the auger is drilled down, unexcavated earth and sand on the upper part of the preceding soil unit is mixed into the left and right preceding soil units, and a high-quality soil wall cannot be formed. The inconvenience is eliminated.
[0035]
In the above-described embodiment, the case where the auger 1 uses a multi-axis auger has been described.
[0036]
【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.
[0037]
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 process explanatory view showing one embodiment of a method for constructing a soil cement pile according to the present invention.
FIG. 2 is an explanatory diagram of a construction procedure for a continuous underground wall using soil cement.
FIG. 3 is a side view of a multi-axis auger used.
FIG. 4 is an explanatory view showing a conventional example.
FIG. 5 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

Claims (2)

While aligning the auger, performing about 40% of the predetermined length by air digging by air discharge, and then injecting the hardening material so that the remaining depth of about 60% is filled with the kneaded material Stirring excavation, and then stirring up by reverse rotation while injecting the curing material so that the kneaded material fills a depth of about several tens of the predetermined length, the kneaded material is Drilling the predetermined length again by forward rotation while injecting the hardening material so as to fill the remaining depth of about 10% of the predetermined length, and then pulling up the auger, and also the leading soil unit at the auger drilling The relationship between the excavation part and the subsequent soil unit excavation part is that the preceding soil unit excavation part has a plurality of holes drilled at an appropriate interval so that the subsequent soil unit excavation part is in between. There is Solidifying [0.102N / mm ² or more (※ Nt = 9.80665)] construction methods of soil cement Pile and performing drilling trailing soil unit drilling portion after waiting for.   In the case of stirring up by reverse rotation while injecting the hardening material, the kneading material is filled to a depth of about 20% of the predetermined length, and again in the normal rotation while injecting the hardening material when drilling the predetermined depth. The method for constructing a soil cement pile according to claim 1, wherein the kneaded material is filled at a depth of about 20% of a predetermined length.

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