JP6380790B2 - Construction method of hydraulic solidifying liquid replacement column - Google Patents

Description

  The present invention relates to a construction method of a hydraulic solidifying material liquid replacement column constructed by a basic construction method for a relatively small structure such as a small-scale building such as a detached house or a soil slab.

  As a basic construction method for detached houses and soil slabs, a columnar improvement method (hereinafter referred to as a “column method”) by a deep mixed processing method is widely adopted. However, in the column method, in situ soil and cement slurry are stirred and mixed, so when cohesive soil with high adhesive strength is targeted, a co-rotation phenomenon occurs, resulting in poor quality due to poor mixing or organic soil. Depending on the type of ground such as, there was a problem that solidification failure occurred. In addition, unexpected soil quality that could not be found in prior ground surveys may appear, and there is always a risk of poor quality.

  As a prior art for solving this problem, a construction method of a hydraulic solidifying material liquid replacement column and a construction apparatus (see Patent Document 1) of a hydraulic solidifying material liquid replacement column have been proposed. In the first place, the cause of poor quality such as poor mixing and solidification of soil cement that is built by stirring and mixing the ground and hydraulic solidification liquid is the mixing and mixing of the hydraulic solidification liquid and the original ground soil In view of the above, the prior art is to build a columnar body with only the hydraulic solidifying material liquid without stirring and mixing the ground soil and the hydraulic solidifying material liquid. Therefore, the built-in hydraulic solidification material liquid replacement column is high strength and high quality because the surrounding in situ soil is not mixed, and even if the surrounding in situ soil is organic soil, solidification failure does not occur, High strength and high quality can be demonstrated without being affected by soil quality.

  Further, as an improved technique related to the technique of Patent Document 1, a drilling head and a drilling apparatus (see Patent Document 2) for a drill rod for building a hydraulic solidifying material liquid replacement column have been proposed. This technique can greatly improve the excavation performance by using a conical excavation head (conical head) provided with a spiral blade on the peripheral surface. In addition, a single-claw type drilling head inevitably generates a lump of dirt that adheres to the claw when rotating, but a conical head can dramatically reduce the amount of sediment that adheres to it, and the drill rod can be pulled up. There is an advantage that earth and sand adhering to the conical head sometimes can be prevented from falling.

  As shown in FIG. 11, the construction procedure by the excavation head and the excavation apparatus of Patent Document 2 includes (a) a excavation head having a spiral blade (spiral excavation blade) 2a and a hydraulic solidifying material liquid discharge port 2b on the side surface ( A hydraulic solidifying material liquid replacement column building apparatus 1 comprising a drilling rod 1a without a soil removal mechanism with a conical head 2 connected to the lower end is mounted on a construction machine (not shown), and the tip center portion of the conical head 2 is attached Set to the pile center position. (B) Excavating while rotating the excavating rod 1a in the forward direction. At this time, the discharge of the hydraulic solidifying material liquid from the discharge port 2b in the conical head 2 is not essential. (C) When the predetermined excavation depth is shallower than the excavation rod length, the excavation is stopped in a state where a part of the upper excavation rod 1a is on the ground. (D) When the predetermined excavation depth is deeper than the length of the excavation rod 1a, the excavation is performed until a part of the excavation rod 1a penetrates into the ground and stops at the predetermined depth position. If the predetermined depth is deeper, the connecting rod may be added. (E) Thereafter, the excavating rod 1a is pulled up in a forward rotation state while discharging the hydraulic solidifying material liquid 5 from the discharge port 2b in the conical head 2. At this time, the pulling speed of the excavating rod 1a and the discharge amount of the hydraulic solidifying material liquid 5 are adjusted so that no negative pressure is generated when the excavating rod 1a is pulled up. Although the rotation direction of the excavation rod 1a at this time may be reverse, the adhering earth and sand of the conical head 2 is supported by the spiral blade 2a although a little, so that the adhering earth and sand of the conical head 2 is prevented from falling. In order to achieve this, forward rotation is preferred. (F) The excavating rod 1a is pulled up to the ground, the filling amount of the hydraulic solidifying material liquid 5 is adjusted, and the hydraulic solidifying material liquid 5 is filled to a predetermined depth position.

JP2011-106253A JP2013-234557A

  The hydraulic solidified liquid replacement column according to the prior art is constructed in order to force the excavation rod 1a into the ground to forcibly displace the ground laterally, and then rub the surrounding ground hole wall with the excavation rod 1a. The replacement column is formed in a columnar shape. From this construction principle, the hydraulic solidifying material liquid replacement column has a feature that the peripheral friction force is large in the vertical support force. However, hydraulic solidification liquid replacement columns are mainly used for small-scale buildings such as detached houses and foundations for soil slabs. A small machine with relatively small capacity (digging torque, pushing force) is assumed, and the construction principle is that the ground is forcibly displaced laterally by the excavating rod 1a, so the outer diameter of the replacement column is simply increased. It is substantially difficult to do because the ground resistance during excavation can easily be assumed to exceed the excavation capability of the construction machine. Therefore, in actual construction, the outer diameter is most often about 200 mm (in practice, the outer diameter of the steel pipe standard is 216.3 mm). The upper limit of the outer diameter depends on the construction conditions such as the ground conditions, but is estimated to be about 300 mm (actually, the outer diameter of steel pipe standard is 318.5 mm) or less. For this reason, it has been difficult to implement a method for increasing the building diameter and further improving the vertical supporting force per replacement column.

  In addition, when using a hydraulic solidifying material liquid replacement column as the foundation of a detached house that is supported by a relatively soft support layer, the breakdown of the vertical support force is the fact that the peripheral friction force is superior to the tip support force. However, when the diameter of the hydraulic solidifying material liquid replacement column is increased, the vertical bearing capacity increases arithmetically, whereas the amount of hydraulic solidifying liquid used increases geometrically. There was a problem in cost because the cost performance decreased. That is, it is difficult to increase the vertical supporting force by increasing the diameter of the hydraulic solidifying material liquid replacement column in terms of both construction and economy.

  Further, although the vertical bearing force of the hydraulic solidifying material liquid replacement column according to the prior art is relatively large in peripheral friction force per unit area, the built diameter is as small as about 200 mm. There was a problem that the vertical supporting force per book was small. Therefore, compared to the column method with a relatively large construction diameter of 500 to 600 mm, the number of columns placed by the hydraulic solidification material liquid replacement column of the same length increases, and the number of columns of the hydraulic solidification material liquid replacement column is the same as the column method. In order to increase the vertical support force per piece, it was necessary to make the construction length relatively long. Therefore, when the hydraulic solidifying material liquid replacement column is adopted, there is a problem that the cost may be higher than the conventional column method.

  In view of these points, the present invention makes a new invention on a method for constructing a columnar hydraulic solidifying material liquid replacement column, without significantly changing the construction procedure, and without requiring a significant change in the construction procedure. The appearance of a hydraulic solidification material liquid replacement column is formed by integrally forming a reinforced ground layer with a predetermined thickness around the hydraulic solidification material liquid replacement column while maintaining the characteristics of stably exhibiting high strength and high quality. While trying to increase the strength by expanding the upper diameter and improve the indentation supporting force performance, the vertical supporting force for the hydraulic solidified liquid replacement column of the ground will be dramatically improved and cost performance will be improved. Is.

  That is, the present invention has been made to solve the above problems, and by excavating the ground using a drilling rod having a ground cutting blade, a hydraulic solidifying material liquid is formed on the outer peripheral surface of the hydraulic solidifying material liquid replacement column. The reinforced ground layer is formed integrally with each other, thereby increasing the peripheral friction force with the surrounding ground of the hydraulic solidification liquid replacement column, resulting in the vertical bearing capacity of the ground against the hydraulic solidification liquid replacement column The purpose is to increase.

In order to achieve the above object, the hydraulic solidifying material liquid replacement column construction method according to claim 1 of the present invention is the hydraulic property that leads to the lower end portion of the excavating rod having the hydraulic solidifying material liquid flow path. Using a hydraulic solidifying material liquid replacement column building apparatus that connects a drilling head having a discharge port for a solidifying material liquid and has at least one ground cutting blade projecting outward on the side surface of the lower part of the drilling rod, while rotating the drill rod by excavation to a predetermined depth of the ground, then drill rod drawn on up while rotating, and when the pulling of the drill rod even without low, while discharging hydraulic solidifying material liquid from the discharge port of the drilling head drilling The rod is pulled up while being rotated, and the cutting portion in the hole and the ground cutting blade is filled with a hydraulic solidifying material liquid.

  By this method, at least the hydraulic solidification material liquid discharged from the discharge port of the excavation head when the excavation rod is pulled up from the ground is an environment in which the negative pressure is not generated in the earth and sand cut around the excavation rod by the ground cutting blade. It is filled below to form a reinforced ground layer, and this reinforced ground layer can be solidified integrally in the ground together with the hydraulic solidifying liquid corresponding to the column shaft portion in the drilling hole after the excavation rod is pulled up. As a result, the hydraulic solidified liquid replacement column after solidification is apparently as the reinforced ground layer is integrally formed on the outer periphery of the column shaft to increase the diameter, and the peripheral frictional force of the entire hydraulic solidified liquid replacement column And an increase in the vertical supporting force of the ground with respect to the hydraulic solidifying liquid replacement column can be realized.

In the hydraulic solidification material liquid replacement column construction method according to claim 2 of the present invention, the hydraulic solidification material liquid is discharged from the discharge port of the excavation head at the time of excavation to a predetermined depth of the ground while rotating the excavation rod. It is characterized by that.

According to this method, since the hydraulic solidified material liquid discharged during excavation is reliably filled in the excavation part formed around the excavation rod, it is preferable to discharge it for ground strengthening.

  The ground cutting blade provided on the excavation rod of the hydraulic solidification liquid replacement column construction device forcibly cuts the ground near the circumference of the excavation rod that hits the rotation trajectory of the ground cutting blade when the column is constructed by this construction device. Therefore, the excavating rod that is constructed while discharging the hydraulic solidification liquid is filled with the hydraulic solidification liquid in addition to the part that corresponds to the column shaft during the excavation and lifting of the drilling rod. If the hardened solid solution is solidified as it is, it becomes a reinforced ground layer. Therefore, in the hydraulic solidified material liquid replacement column after solidification, a reinforced ground layer is formed by the hydraulic solidified material liquid on the outer peripheral side of the column shaft portion.

  This reinforced ground layer by the hydraulic solidification material liquid is integrated with the high-strength column shaft portion made of a hydraulic solidification material liquid that is filled in the drilling hole from which the excavation rod has been pulled out and does not contain earth and sand. As a result, a hydraulic solidifying material liquid replacement column having an appearance in which the outer diameter of the entire column is enlarged is constructed. The hydraulic solidifying material liquid replacement column constructed in this way strengthens the ground in the region larger than the diameter of the excavating rod, and increases the peripheral frictional force of the hydraulic solidifying material liquid replacement column. This will increase the vertical support force of the ground for the hard solidifying material liquid replacement column.

As long as at least one ground cutting blade protrudes, two ground cutting blades are fixed at an axially symmetric position on the outer periphery of the excavating rod (including a case where the ground cutting blades are provided at different levels in the axially symmetric position). If this is the case, it becomes easier to balance the excavating rod digging force and the pulling force during pulling. Therefore, the excavation rod can be prevented from decentering against the unbalanced resistance load that the ground cutting blade receives from the earth and sand, and the backlash of the excavation rod during construction is smaller than when only one ground cutting blade is used. This is preferable because the impact and load on the machine can be reduced.
Further, the two ground cutting blade positions may be fixed in steps in the axial direction of the excavation rod.

The form of the excavation head is not particularly limited, and a conventionally known one can be adopted, but a spiral in a direction to push up the excavated earth and sand at the time of the vertical protrusion along the peripheral surface or the normal rotation of the excavating rod on the peripheral surface. A conical shape with fixed wings is preferable because the excavation in the ground is good. In particular, in the case of a spiral blade that pushes up the excavated sediment during the forward rotation of the excavating rod, the formation of the excavated soil does not occur physically in the excavated part. Since there is no fear of mixing, it is more preferable.

  In the present invention, the hydraulic solidifying material liquid is a self-hardening powder and water such as Portland cement that is hydrated and solidified with water as main components, for example, cement slurry (cement milk), A mortar containing fine aggregate made of sand, etc., and a fluid that is made of (cement) concrete that also contains coarse aggregate such as gravel or crushed stone with a small diameter that can be discharged from a discharge port, and that can be pumped. .

  According to the present invention, by excavating the ground using a drilling rod having a ground cutting blade, it is possible to form a hydraulic solidifying material liquid replacement column integrally with a reinforced ground layer on the outer peripheral surface of the column shaft. Thus, the peripheral friction force with the surrounding ground of the hydraulic solidifying material liquid replacement column can be increased, and the vertical supporting force of the ground with respect to the hydraulic solidifying material liquid replacement column can be increased.

  The present invention has been briefly described above. The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.

It is a front view of the principal part of the hydraulic solidification material liquid substitution column construction apparatus used by this invention. It is a side view of the hydraulic solidification material liquid substitution column construction apparatus shown in FIG. It is the sectional view on the AA line of FIG. It is explanatory drawing which shows the construction procedure of a hydraulic solidification material liquid replacement column. It is a cross-sectional view which shows the integral structure of the column axial part and reinforced ground layer of the constructed hydraulic solidification material liquid replacement column. Sectional plan view (a) of excavation rod (inner pipe omitted) implemented in the hydraulic solidification material liquid replacement column construction apparatus shown in FIG. 1, and hydraulic solidification material liquid constructed by the construction apparatus shown in (a) It is a section explanatory view (b) of a substitution column. It is a front view of the principal part of the other hydraulic solidification material liquid substitution column construction apparatus used by this invention. FIG. 8 is a sectional view taken along line BB in FIG. 7. Sectional plan view (a) of excavation rod (inner pipe omitted) implemented in the hydraulic solidifying material liquid replacement column building apparatus shown in FIG. 7, and hydraulic solidifying material liquid built by the building apparatus shown in (a) It is a section explanatory view (b) of a substitution column construction device. It is a front view of the principal part of the further another hydraulic solidification material liquid substitution column construction apparatus used by this invention. It is explanatory drawing which shows the conventional construction procedure of a hydraulic solidification material liquid replacement column.

  Hereinafter, a hydraulic solidifying material liquid replacement column building method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 10.

  1 and 2 are a front view and a side view of a hydraulic solidifying material liquid replacement column building apparatus used in the hydraulic solidifying material liquid replacement column building method of the present invention, and FIG. 3 is a sectional view taken along line AA in FIG. is there. This hydraulic solidifying material liquid replacement column building apparatus 1 includes a drilling rod 1a having a drilling head 2 connected to the lower end. On the excavation rod 1a, one ground cutting blade 3 is fixed to the lower peripheral surface so as to protrude outward. The ground cutting blade 3 is provided above the lower end H of the excavation rod 1a. Thereby, when the excavation rod 1a is rotated and pulled up, the hole wall surface can be rubbed and strengthened. In this embodiment, the excavation head 2 has a conical shape, and a spiral excavation blade (spiral blade) 2a is fixed on a side surface of the excavation head 2 and a discharge port 2b for hydraulic solidifying material liquid is provided. . A backflow prevention valve 2c for preventing backflow of earth and sand is attached to the discharge port 2b. The discharge port 2b communicates with the inner pipe 1d which is a passage (flow path) for the hydraulic solidifying material liquid.

The excavation head 2 is not particularly limited, and a conventionally known one can be employed. However, when the conical shape is obtained by fixing the spiral excavation blade 2a on the side surface as in this example, the excavation performance is good. Not only that, the formation of the soil block in the excavation part is physically impossible, and therefore, there is less possibility of the excavation soil block being mixed into the hydraulic solidifying material liquid replacement column, which is preferable.
The excavation head 2 may be fixed to the excavation rod 1a or may be detachably connected. For example, when the excavation head 2 is detachably connected by a joint, there is an advantage that excavation head 2 that is heavily worn can be easily replaced. When the excavation head 2 is fixed to the excavation rod 1a by welding, for example, the joint portion is not necessary, and the manufacturing cost is reduced.

  The shape of the ground cutting blade 3 of the present embodiment may be a plate-like or bar-like protruding blade that can rotate and cut the ground. For example, a form in which a thick plate material made of the same material (metal) as the excavation rod 1a is fixed at a predetermined angle (for example, 30 °) as shown in FIG. 2 can be shown. In addition, it can also be fixed horizontally without inclining. This ground cutting blade cuts the surrounding ground while rotating when the excavation rod is excavated and pulled up.

Next, a method of building a hydraulic solidifying material liquid replacement column using the hydraulic solidifying material liquid replacement column building apparatus 1 will be described.
FIGS. 4A to 4E are explanatory views showing a construction procedure of the hydraulic solidifying material liquid replacement column. The hydraulic solidifying material liquid replacement column building apparatus 1 used in this replacement column building method is provided with one ground cutting blade 3 on the lower peripheral surface of the drill rod 1a shown in FIGS. 1 and 2, and the drill rod A conical excavation head 2 having a spiral excavation blade (spiral blade) 2a fixed to the side surface is connected to the lower end of 1a.
First, the center of the excavation rod 1a tip attached to the auger motor (not shown) of the construction apparatus is set according to the pile center position of the ground (FIG. 4 (a)). Next, the excavating rod 1a is fed forward into the ground while rotating forward, and is excavated and pressed to a predetermined depth (FIGS. 4B and 4C). At this time, it is not essential to discharge the hydraulic solidified material liquid from the discharge port 2b of the excavation head 2, but the hydraulic solidified material liquid discharged at the time of excavation is reliably filled in the excavation part formed around the excavation rod. For this reason, discharging is preferable for strengthening the ground. Thereafter, the excavation rod 1a is rotated and pulled up while discharging the hydraulic solidifying material liquid from the discharge port 2b of the excavation head 2 (FIG. 4D). At this time, the pulling speed and the hydraulic solidifying material liquid discharge amount are balanced so that no negative pressure is generated. Preferably, the liquid level position formed by the discharged hydraulic solidifying material liquid is always positioned above the ground cutting blade 3 and maintained. The excavation rod 1a is rotated and pulled up, and the top level (pile head level) is adjusted to a predetermined position by replenishing hydraulic solidifying material liquid or the like (FIG. 4 (e)). Here, the excavation rod 1a can be pulled up by rotating either forward or reverse. In addition, it is preferable for discharging the hydraulic solidifying material liquid not only when the excavating rod 1a is pulled up but also when excavating for strengthening the ground.
When the hydraulic solidifying material liquid is discharged during excavation, the ground cutting blade 3 rotates while cutting the ground around the excavating rod 1a while the portion where the discharged hydraulic solidifying material liquid exists is discharged. The hydraulic solidifying material liquid thus made comes to exist in the peripheral ground where it has been cut, and the peripheral ground of the excavation rod 1a is strengthened.

According to this hydraulic solidification material liquid replacement column construction method, the ground is generated while the excavation rod 1a having the excavation head 2 connected to the lower end and the ground cutting blade 3 fixed to the lower peripheral surface is rotated forward. The excavation rod 1a is rotated while the excavation rod 1a is rotated while the hydraulic solidification material liquid is discharged from the discharge port 2b provided in the excavation head 2, and the excavation rod 1a is lifted below the excavation hole. To fill with hydraulic solidifying material liquid. During this operation, the ground cutting blade 3 cuts the ground around the excavation rod 1a, and this cutting ground is reinforced with a hydraulic solidifying material liquid. For this reason, after hardening of the hydraulic solidification material liquid, as shown in FIG. 5, the hydraulic solidification which integrally has the reinforcement | strengthening ground layer 4b in the surrounding surface of the column shaft part 4a of the center part which consists only of hydraulic solidification material liquid. The material liquid replacement column 4 is constructed. The manner in which the reinforced ground layer 4b is formed on the peripheral surface of the column shaft portion 4a will be described with reference to FIGS.
6A is a cross-sectional plan view in which the inner pipe 1d of the excavation rod 1a of the hydraulic solidifying material liquid replacement column building apparatus 1 of the embodiment shown in FIG. 1 is omitted, and FIG. 6B is built by the building apparatus. FIG. 6 is a cross-sectional explanatory view of a hydraulic solidifying material liquid replacement column 4. Since the ground cutting blade 3 of the hydraulic solidifying material liquid replacement column construction apparatus 1 is one piece, for example, the excavating rod 1a is rotated as shown in FIG. 6A while discharging the hydraulic solidifying material liquid. When it is digged up or pulled up, the hydraulic solidifying material liquid is mixed or infiltrated into the rotation locus portion of the ground cutting blade 3 and is filled and filled in the peripheral surface of the column shaft portion 4a as shown in FIG. The hydraulic solidifying material liquid replacement column 4 having the reinforced ground layer 4b integrally is built. The hydraulic solidified material liquid replacement column 4 thus constructed becomes apparently as the reinforced ground layer 4b is integrally formed on the outer periphery of the column shaft portion 4a to increase the diameter, and the hydraulic solidified material liquid replacement column 4 as a whole. It is possible to realize an increase in the peripheral surface friction force and an increase in the vertical support force of the ground for the hydraulic solidifying material liquid replacement column 4.
Further, since there is an interval H below the ground cutting blade 3 in the excavation rod 1a, when the excavation rod 1a is rotated and pulled up, the excavation rod 1a between the intervals H rubs the hole wall surface. To be strengthened.

  FIG. 7 is a front view of a main part of another hydraulic solidifying material liquid replacement column building apparatus used in the present invention, and FIG. 8 is a sectional view taken along line BB in FIG. This hydraulic solidifying material liquid replacement column building apparatus 1A includes a drilling rod 1a having a drilling head 2 connected to the lower end. In the excavation rod 1a, one (two in total) ground cutting blades 3 are axially symmetrically arranged on the lower peripheral surface. The ground cutting blade 3 is provided above the lower end H of the excavation rod 1a. Thereby, when the excavation rod 1a is rotated and pulled up, the hole wall surface can be rubbed and strengthened. The excavation head 2 has a conical shape, and a spiral excavation blade (spiral blade) 2a is fixed on a side surface of the excavation head 2 and a discharge port 2b for hydraulic solidifying material liquid is provided. A backflow prevention valve 2c for preventing backflow of earth and sand is attached to the discharge port 2b. The discharge port 2b communicates with the inner pipe 1d which is a passage (flow path) for the hydraulic solidifying material liquid.

  Since the excavation head 2 has a conical shape in which a spiral excavation blade 2a is fixed on the peripheral surface, not only excavation is good, but also the formation of a lump in the excavation part cannot be physically performed. There is little risk of contamination of excavated soil blocks during construction. The excavation head 2 may be fixed to the excavation rod 1a or may be detachably connected. For example, when the excavation head 2 is detachably connected by a joint, there is an advantage that excavation head 2 that is heavily worn can be easily replaced. When the excavation head 2 is fixed to the excavation rod 1a by welding, for example, the joint portion is not necessary, and the manufacturing cost is reduced.

  The method of building a hydraulic solidifying material liquid replacement column using such a hydraulic solidifying material liquid replacement column building apparatus 1A is similar to the case described with reference to FIG. Set according to the center position, the excavation rod 1a is fed forward into the ground while rotating forward, and the excavation press fits to a predetermined depth. Although it is not essential to discharge the hydraulic solidifying material liquid during excavation, the hydraulic solidifying material liquid discharged during excavation is surely filled in the excavation part formed around the excavation rod. Preferred for strengthening. Subsequently, the excavation rod 1 a is rotated and pulled up while discharging the hydraulic solidification material liquid from the discharge port 2 b of the excavation head 2. At this time, the pulling speed and the hydraulic solidifying material liquid discharge amount are balanced so that no negative pressure is generated. Furthermore, preferably, the liquid level formed by the discharged hydraulic solidifying material liquid is always positioned above the ground cutting blade 3 and is maintained. The excavation rod 1a is rotated and pulled up, and the top level is adjusted to a predetermined position by replenishing hydraulic solidifying material liquid or the like. Here, the excavation rod 1a may be rotated either forwardly or reversely when it is pulled up.

According to this hydraulic solidifying material liquid replacement column construction method, the inside of the excavation hole where the excavating rod 1a is pulled up is filled with the hydraulic solidifying material liquid from below, and the ground cutting blade 3 cuts the ground around the excavating rod 1a. However, in order to fill the hydraulic solidifying material liquid, the hydraulic solidifying material liquid replacement column 4 having the reinforced ground layer 4b on the peripheral surface of the column shaft portion 4a is constructed after the hydraulic solidifying material liquid is cured. 9A and 9B illustrate how the reinforced ground layer 4b is formed on the peripheral surface of the column shaft portion 4a when the hydraulic solidifying material liquid replacement column building apparatus 1A shown in FIG. 7 is used.
9A is a cross-sectional plan view in which the inner pipe 1d of the excavation rod 1a of the hydraulic solidifying material liquid replacement column building apparatus 1A of the embodiment shown in FIG. 7 is omitted, and FIG. 9B is built by the building apparatus. FIG. 6 is a longitudinal sectional explanatory view of a hydraulic solidifying material liquid replacement column 4. Since the two ground cutting blades 3 of this hydraulic solidifying material liquid replacement column construction apparatus 1A are provided at the axially symmetric position of the excavating rod 1a, for example, FIG. 9A while discharging the hydraulic solidifying material liquid. When the excavation rod 1a is rotated and advanced as shown in FIG. 9, the discharged hydraulic solidifying material liquid and the cut ground soil are agitated in the passage portion of the ground cutting blade 3, as shown in FIG. 9B. Thus, the reinforced ground layer 4b is formed. Therefore, as shown in FIG. 9 (b), the hydraulic solidifying material liquid replacement column 4 having the reinforced ground layer 4b integrally is built on the peripheral surface of the column shaft portion 4a. In this case, since at least two ground cutting blades 3 are fixed at the axially symmetric position on the outer periphery of the excavating rod 1a (including the case where the excavating rod 1a is provided in a stepped manner at the axially symmetric position), This makes it easier to balance the lifting force. Accordingly, the excavation rod 1a can be prevented from decentering even against unbalanced resistance load that the ground cutting blade 3 receives from the earth and sand, and the excavation rod 1a is less loose at the time of construction than when only one ground cutting blade is used. The impact and load on the construction machine can be reduced. Further, since there is an interval H below the ground cutting blade 3 in the excavation rod 1a, when the excavation rod 1a is rotated and pulled up, the excavation rod 1a between the intervals H rubs the hole wall surface. To be strengthened.

  FIG. 10 is a front view of a main part of still another hydraulic solidifying material liquid replacement column building apparatus used in the present invention. This hydraulic solidifying material liquid replacement column building apparatus 1B has a peripheral surface in place of the spiral excavation blade (spiral blade) 2a of the excavating head 2 in the hydraulic solidifying material liquid replacement column building apparatus 1 shown in FIGS. Are the same as those of the embodiment shown in FIGS. 1 to 3, and the same components are described with the same reference numerals.

  This hydraulic solidifying material liquid replacement column building apparatus 1B includes a drilling rod 1a having a drilling head 2 connected to the lower end. A ground cutting blade 3 is fixed to the excavating rod 1a so as to protrude outwardly on the lower peripheral surface. In this embodiment, the excavation head 2 has a conical shape, and on its side surface (circumferential surface), a vertical protrusion 2d along the peripheral surface is fixed, and a hydraulic solidifying material liquid discharge port is provided. 2b is provided. When the ridge 2d is excavated into the ground, the ridge 2d excavates the ground and improves the excavation performance. Therefore, it is sufficient that at least one ridge 2d is provided. In this example, the case where four pieces are provided on the outer periphery at equal intervals is shown. A backflow prevention valve 2c for preventing backflow of earth and sand is attached to the discharge port 2b. The discharge port 2b communicates with the inner pipe 1d which is a passage (flow path) for the hydraulic solidifying material liquid.

Since the excavation head 2 in this example has a conical shape provided with vertical protrusions 2d along the peripheral surface, the excavation head 2 can be excavated in the ground while excavating the ground with the protrusions 2d, and the excavation performance is improved. Workability is improved.
The shape of the ground cutting blade 3 may be a plate-shaped or rod-shaped protruding blade that can rotate and cut and agitate the ground, and can be the one described in the above embodiment as an example. The rest is the same as the embodiment shown in FIGS.

The method of building a hydraulic solidifying material liquid replacement column using this hydraulic solidifying material liquid replacement column building apparatus 1B is the same as the method shown in FIG.
Therefore, according to this hydraulic solidifying material liquid replacement column building method, as in the embodiment shown in FIGS. 1 to 3, the inside of the excavation hole in which the excavation rod 1a is pulled up is the hydraulic solidification material from below. Since the ground cutting blade 3 is filled with the hydraulic solidifying material liquid while cutting the ground around the excavation rod 1a, after the hardening of the hydraulic solidifying material liquid, as shown in FIG. 5 and FIG. 6 (b). The hydraulic solidifying material liquid replacement column 4 having the reinforced ground layer 4b is built on the peripheral surface of the column shaft portion 4a.

  As described above, according to the embodiment, the hydraulic solidifying material liquid replacement column building apparatus 1, 1 </ b> A, 1 </ b> B for building the hydraulic solidifying material liquid replacement column 4 in the drilled hole using the excavating rod 1 a is used. In addition, when at least one ground cutting blade 3 is fixed to the lower peripheral surface of the excavation rod 1a, when the ground is excavated using the excavation rod 1a having the ground cutting blade 3, the hydraulic property The solidified material liquid replacement column 4 can be integrally formed with the outer peripheral surface of the column shaft portion 4a and the reinforced ground layer 4b can be integrally formed, thereby increasing the peripheral frictional force with the peripheral ground of the hydraulic solidified material liquid replacement column 4. As a result, the vertical supporting force of the ground with respect to the hydraulic solidifying material liquid replacement column 4 can be increased.

  The hydraulic solidifying material liquid replacement column construction method of the present invention increases the peripheral friction force with the surrounding ground of the hydraulic solidifying material liquid replacement column and increases the vertical supporting force of the ground with respect to the hydraulic solidifying material liquid replacement column. It is useful for the construction method of hydraulic solidification material liquid replacement columns that are built by the basic construction method of small-scale buildings such as detached houses and relatively light structures such as soil slabs. It is.

DESCRIPTION OF SYMBOLS 1, 1A, 1B Hydraulic solidification material liquid substitution column construction apparatus 1a Drilling rod 2 Drilling head 2a Spiral excavation blade 2b Discharge port 2c Backflow prevention valve 2d Projection 3 Ground cutting blade 3a Horizontal piece 3b Inclined piece 4 Hydraulic solidification material Liquid replacement column 4a Column shaft 4b Reinforced ground layer

Claims (2)

A drilling head having a hydraulic solidifying material liquid discharge port connected to the flow path is connected to a lower end portion of the drilling rod having a hydraulic solidifying material liquid flow path, and at least one side surface of the lower part of the drilling rod the ground cutting blade outward with hydraulic solidifying material liquid replacement column construction device which projects, while rotating the drill rod by excavation to a predetermined depth of the ground, pulled up while rotating the subsequent drill rod, without low In both cases, when the excavation rod is lifted, the excavation rod is pulled up while rotating the excavation rod while discharging the excavation head from the discharge port of the excavation head, and the cutting portion of the excavation hole and ground cutting blade is filled with the hydraulic solidification material liquid. A hydraulic solidifying material liquid replacement column construction method characterized by that. 2. The hydraulic solidifying material liquid replacement column construction method according to claim 1, wherein the hydraulic solidifying material liquid is discharged from a discharge port of a drilling head when the excavation rod is rotated while excavating to a predetermined depth of the ground.

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