JP6539925B2 - Construction method of hydraulic solidifying material liquid displacement column - Google Patents

Description

  The present invention relates to a hydraulic solidifying material liquid displacement column construction apparatus used for a foundation method of a relatively small structure such as a small scale building such as a detached house or a soil slab.

  A pillar improvement method (hereinafter referred to as "column method") by deep mixing method is widely adopted as a foundation method for detached houses and soil slabs. However, since the column method stirs and mixes the in-situ ground soil and the cement slurry, the co-rotation phenomenon occurs when the cohesive soil with high adhesive strength is targeted, causing poor quality due to poor mixing, or organic soil Depending on the type of ground such as, there is a problem that solidification failure occurs. In addition, unexpected soil quality that could not be found in the ground survey in advance may appear, and there is always a risk of poor quality.

  As prior art for solving this problem, a method of constructing a hydraulic solidifying agent liquid displacement column and a construction apparatus of the hydraulic solidifying agent liquid displacement column have been proposed (see Patent Document 1). In the first place, agitation and mixing of the hydraulic solidifying material solution and the in-situ soil is the cause that causes poor quality such as mixing failure and solidification failure of the soil cement which is built by stirring and mixing the ground soil and the hydraulic solidifying material solution. In view of the above, in the prior art, the columnar body is constructed only with the hydraulic solidifying agent solution without stirring and mixing the ground soil and the hydraulic solidifying agent solution. Therefore, the built-up hydraulic solidified material liquid displacement column has high strength and high quality because the surrounding in-situ soil is not mixed, and solidification failure does not occur even if the surrounding in-situ soil is an organic soil, High strength and high quality can be exhibited regardless of the soil quality.

  Moreover, as an improvement technique regarding the technique of patent document 1, the drilling head and drilling apparatus (refer patent document 2) of the drilling rod for hydraulic-solidification liquid solution substitution column construction are proposed. This technique can greatly improve the drilling performance by using a conical drilling head (conical head) provided with helical wings on the side. In addition, although a single-cone type conical head inevitably generates soil lumps attached to the claws at the time of rotary digging, the conical head can dramatically reduce the amount of sediment attached to it, and further, the drilling rod is pulled up There is an advantage that the earth and sand attached to the conical head can sometimes be prevented from falling.

The construction by the drilling head and the drilling apparatus of Patent Document 2 is a drilling head (conical head) having a spiral blade 13 and a discharge port 14 for hydraulic solidifying material solution as shown in FIG. A hydraulic solidifying material liquid displacement column in which a small diameter connecting rod 11b serving as a grip portion of an auger motor for rotating the drilling rod 11a is connected above a large diameter drilling rod 11a having no earth removing mechanism connected to the lower end 12 The construction apparatus 11 is used.

Then, the hydraulic solidifying material liquid displacement column construction apparatus 11 is mounted on a construction machine (not shown), and as shown in FIG. 5 , (a) set the tip center of the conical head 12 at the pile center position. . (B) Excavating while rotating the drilling rod 11a forward. At this time, the discharge of the hydraulic solidifying material solution from the discharge port 14 in the conical head 12 is not essential. (C) In the case where the predetermined drilling depth is shallower than the length of the drilling rod 11a, the drilling is stopped in a state where a part above the drilling rod 11a is on the ground. (D) If the predetermined drilling depth is deeper than the length of the drilling rod 11a, drilling is performed until a part of the connecting rod 11b penetrates into the ground, and stops at the predetermined depth position. When the predetermined depth is deeper, the connection rod 11b may be added. (E), (f) Thereafter, while discharging the hydraulic solidifying material solution 15 from the discharge port 14 in the conical head 12, the digging rod 11a is pulled up in a state of normal rotation. At this time, the pulling speed of the drilling rod 11a and the discharge amount of the hydraulic solidifying material solution 15 are adjusted to prevent the generation of negative pressure accompanying pulling of the drilling rod 11a. At this time, although the deposited soil on the drilling head 12 is slightly supported by the digging wing 13, it is better to rotate the drilling rod 11 a forward to prevent the deposited soil on the drilling head 12 from falling. preferable. (G) The drilling rod 11a is pulled up to the ground to adjust the amount of the hydraulic solidifying agent liquid 15, and the hydraulic solidifying agent liquid 15 is charged to a predetermined top end position.

By the way, in the hydraulic solidifying material liquid displacement column construction apparatus 11, as shown in FIG. 4 , a large diameter drilling rod 11a for excavating a region forming the hydraulic solidifying material liquid displacement column of the ground and the drilling rod 11a are rotated. A small-diameter connecting rod 11b to be a grip of the auger motor is connected. Since hydraulic solidifying material liquid displacement columns are assumed to be used as the foundation of light structures such as detached houses and slabs between soils, the construction machine itself is usually a compact column improvement machine or piling machine Is used. Therefore, the length of the digging rod 11a that can be attached to the small construction machine main body is about 4 m at maximum, and the small diameter connecting rod 11b is attached to the digging rod 11a.

JP, 2011-106253, A JP, 2013-234557, A

However, in the ground excavation by the hydraulic solidifying material liquid displacement column construction device 11, when the construction depth of the hydraulic solidifying liquid liquid substitution column exceeds 4 m, the digging rod 11a completely penetrates the ground, as shown in FIG. As shown in (a), the small-diameter connecting rod 11b further penetrates into the ground by a necessary length. Then, a gap G is generated between the connection rod 11a in the borehole H through which the drilling rod 11a has passed and the wall surface of the borehole H. Therefore, the wall surface of the borehole H at that portion is a free surface that can not be supported by anything It becomes. Therefore, from the moment when the wall surface of the drilling hole H becomes a free surface, the ground pushed and expanded by the drilling rod 11a starts elastic return in the direction of the arrow for reducing the diameter of the drilling hole H as shown in FIG . Earth pressure or water pressure promotes the movement, and the drill hole H further reduces its diameter at that site.

Next, the digging rod 11a whose digging has reached a predetermined depth stops digging and is pulled up as shown in FIG. 6 (c) while discharging the hydraulic solidifying material solution from the discharge port 14 of the digging head 12. At this time, the elastic return portion P of the wall surface of the excavated hole H reduced by the flat shoulder (stepped portion between the excavating rod 11a and the connecting rod 11b) 11c of the excavating rod 11a protruding outward from the connecting rod 11b. Is scraped off, and the scraped soil Q is lifted while being accumulated on the shoulder 11c as shown in FIGS. 6 (c) and 6 (d), and finally it is lifted to the ground as shown in FIG. 6 (e) . Exhausted. If the total amount of the discharged soil and sand Q becomes a non-negligible amount at the construction site, there is a disadvantage that a secondary disaster in the digging operation may be caused and an extra cost such as disposal of residual soil may occur. In addition, if the earth and sand accumulated on the shoulders fall during the raising operation of the drilling rod, it may hit a worker who is working on the ground, resulting in personal injury.

The present invention solves the above-mentioned conventional problems, and the object of the present invention is to remove the earth and sand of the elastic return portion of the drill hole reduced by the elastic return of the wall surface when pulling up the drill rod from the drill hole. Is forced to knead the wall by means of a conical connection, so that the elastic return of the earth and sand is avoided, and the secondary work on the excavation work by the earth and sand accumulated on the earth An object of the present invention is to provide a hydraulic solidifying material liquid displacement column construction apparatus capable of avoiding the occurrence of disasters and the occurrence of waste soil treatment costs.

In order to achieve the above object, a hydraulic solidifying material liquid displacement column construction device according to claim 1 of the present invention is provided above a large-sized drilling rod for excavating a region forming a hydraulic solidifying liquid liquid displacement column of ground. A hydraulic solidifying material liquid displacement column construction apparatus in which a small diameter connecting rod serving as a grip portion of an auger motor for rotating the drilling rod is connected;
A plurality of triangular plate pieces which are inclined gradually lower in height from the digging rod side to the connecting rod side are erected at predetermined intervals around the rod directly above the step portion generated between the digging rod and the connecting rod It is characterized in that a suitable conical connection is provided .

  With this configuration, when the drilling rod is rotated and pulled up from the drilling hole, the earth and sand from which the elastic return of the drilling hole is scraped off by the flat shoulder (step between the drilling rod and the connecting rod) at the upper end of the drilling rod is The soil is supported by the shoulders and lifted while being filled and accumulated between the triangular plate pieces of the connection portion, but since the connection portion is also rotated by the rotation of the digging rod, the soil accumulated and filled between the triangular plate pieces is It is filled and fixed between the triangular plate pieces, and the whole triangular plate pieces form a conical lump. Therefore, after that, since it is pulled up in the state of a conical lump, it becomes a conical lump similarly to the case where the connection between the drilling rod and the connecting rod is formed conically. The joint portion is rotated in the direction of the outer diameter of the drilling rod while rotating so that the earth and sand of the elastic return of the wall surface in the drilling hole opposite to the outer periphery of the connecting rod are kneaded on the wall surface side of the drilling hole by the conical gradient. Push the hole until it reaches the original drilling hole diameter. For this reason, the situation in which the earth and sand of the elastic return on the wall surface of the hole is scraped off and lifted does not occur, and the initial hole diameter for drilling is maintained after pulling up the drilling rod. As a result, regardless of the pulling up of the drilling rod, it is prevented that the earth and sand of the elastic return in the drilling hole are placed on the step portion and discharged to the ground and accumulated as residual soil. The earth and sand discharged to the ground is only a portion of the lump that is filled and fixed between the triangular plate pieces and is small.

Further, in the hydraulic / solidifying material liquid displacement column construction apparatus according to claim 2 of the present invention, the maximum rotation diameter of the triangular plate piece is equal to or less than the drilling rod rotation diameter.

According to this configuration, since the maximum rotation diameter of the triangular plate piece is equal to or less than the drilling rod rotation diameter, the triangular plate piece does not scrape off the wall surface of the digging hole when pulling up the drilling rod. Further, the maximum diameter of rotation of the conical lump formed by filling and fixing the earth and sand between the triangular plate pieces is also equal to or less than the diameter of the drilling rod. Therefore, when pulling up the drilling rod, the elastic return portion is made to knead the earth and sand of the elastic return on the wall surface of the drilling hole while avoiding scraping off the wall surface of the drilling hole in the direction of expanding the drilling hole diameter. The borehole can then be maintained at the original borehole diameter.
In the present invention, the term "large diameter" of the large diameter drilling rod and "small diameter" of the small diameter connection rod are used as terms of large diameter and small diameter in comparison of the diameter of the drilling rod and the connecting rod. doing.

  According to the present invention, when pulling up the drilling rod from the drilled hole, the earth and sand of the elastic return generated on the wall surface of the drilled hole are not scraped off and discharged to the ground, whereby the sediment is deposited on the ground In this way, it is possible to prevent the occurrence of secondary disasters and waste disposal costs due to landslide falling in the excavation site and personal injury due to the fall of soil accumulated on the shoulder during the raising of the drilling rod.

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

It is a front view which shows the hydraulic-hardening-agent liquid displacement column construction apparatus by embodiment of this invention. It is an enlarged perspective view showing an essential part of the hydraulic solidifying material liquid replacement column construction device shown in FIG. Is a perspective view for explaining the operation of the hydraulic solidifying material liquid replacement column shown in FIG. It is a front view which shows the conventional hydraulic solidifying material liquid displacement column construction apparatus. Explanatory drawing (a) (b) (c) (d) (e) (f) which shows the construction procedure of hydraulic hardening material liquid substitution column implemented using hydraulic solidification material liquid substitution column construction device in Drawing 4 (G). It is explanatory drawing (a) (b) (c) (d) (e) which shows the condition where the elastic return which arises on the wall surface of a wellbore in the construction procedure of FIG. 5 is discharged | emitted on the ground.

  The hydraulic solidifying material liquid displacement column construction apparatus according to the embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a front view of a hydraulic solidifying material liquid displacement column constructing apparatus according to an embodiment of the present invention, and FIG. 2 is an enlarged perspective view showing the main part of the hydraulic solidifying material liquid displacement column construction apparatus shown in FIG. FIG. 3 is a perspective view for explaining the operation of the hydraulic / solidifying material / liquid displacement column constructing apparatus shown in FIGS. 1 and 2 .
A hydraulic solidifying material liquid displacement column construction apparatus 1E of this embodiment is an auger motor for rotating the digging rod 1a above a large diameter drilling rod 1a for digging a region forming a hydraulic solidifying liquid fluid displacement column of ground. The connecting rod 1b having a small diameter is connected, and the connecting rod 1b is connected to the connecting rod 1b directly above the stepped portion (shoulder) 1e generated between the drilling rod 1a and the connecting rod 1b. A plurality of triangular plate pieces 7 whose height gradually inclines toward the lower side are erected at predetermined intervals around the rod, and a connection portion 6 having a conical shape as a whole is provided. That is, the connecting rod 1b is connected to the upper end of the digging rod 1a via the connecting portion 6 in which a plurality of triangular plate pieces 7 are erected at predetermined intervals around the periphery.

Thereby, when the drilling rod 1a is rotated and pulled up from the drilling hole, the elastic return portion P of the drilling hole is scraped off by the flat shoulder (step between the drilling rod 1a and the connecting rod 1b) 1e at the upper end of the drilling rod 1a. The deposited soil is supported by being supported on the step portion (shoulder portion) 1e and lifted up while being filled and accumulated between the triangular plate pieces 7 of the connection portion 6, but the connection portion 6 is also rotated by rotation of the digging rod 1a. Therefore, the earth and sand packed and accumulated between the triangular plate pieces 7, 7 are filled and fixed between the triangular plate pieces 7, 7, and together with the triangular plate pieces 7, as shown in FIG. Is formed into a lump 8 of Therefore, after that, because the raised while holding the conical masses 8, a circular conical connecting portion 6 became masses 8, borehole facing the connecting rod 1b periphery by conical slope The earth and sand of the elastic return portion P of the wall surface in the above are kneaded on the wall surface side of the drilling hole, and while rotating, they are pushed outward in the outer diameter direction of the drilling rod 1a to the position of the initial drilling hole diameter. For this reason, the situation that the earth and sand of the elastic return portion P on the wall surface of the hole is scraped off and lifted (lifted) does not occur, and the initial digging hole diameter is maintained after pulling up the drilling rod 1a. As a result, regardless of the pulling up of the drilling rod 1a, the earth and sand of the elastic return P in the drilling hole is placed on the step portion 1e and discharged to the ground to be prevented from being accumulated as residual soil. It is also possible to prevent secondary disasters at the excavation site and accompanying costs such as waste disposal.

The maximum rotation diameter of the triangular plate pieces 7 in the construction apparatus 1E is an equal to or less than the rotation diameter of the drill rod 1a. Since the drilling hole is formed by the drilling rod 1a, the drilling hole diameter is substantially the same as the diameter of the drilling rod 1a. Therefore, when the maximum rotation diameter of the triangular plate piece 7 is larger than the rotation diameter of the drilling rod 1a, the wall surface of the drilling hole is scraped off. It is preferable that the maximum rotation diameter of the triangular plate piece 7 is equal to or less than the rotation diameter of the digging rod 1a because the triangular plate piece 7 does not scrape off the wall surface of the digging hole when pulling up the digging rod 1a. Further, if the maximum rotation diameter of the triangular plate piece 7 is equal to or less than the rotation diameter of the digging rod 1a, the earth and sand are filled and fixed between the triangular plate pieces 7, 7 The maximum rotation diameter is also equal to or less than the rotation diameter of the drilling rod 1a. Therefore, when pulling up the drilling rod 1a, the earth and sand of the elastic return portion P can be removed from the wall surface of the drilling hole while avoiding scraping off the wall surface of the drilling hole in the direction of expanding the drilling hole diameter. The borehole can be maintained at the original drilling bore diameter by

In FIG. 2 , a part of the triangular plate piece 7 of the connection portion 6 is cut out, but this cutaway portion is a portion to which the pin 9 of the joint is attached. This notch is omitted in FIG. In addition, this notch part is required when it is set as the structure which provides the connection part 6 which has the triangular-shaped board piece 7 in the upper end of the digging rod 1a with a coupling, and is not necessarily required.

The conical connection 6 may also be provided integrally with the drilling rod 1a and / or the connecting rod 1b. Moreover, it can also be installed and used between the drilling rod 1a and the connecting rod 1b as an adapter which is an independent single installation part. In this case, when the connection portion 6 is worn due to frictional force in the ground excavating process, it can be replaced with a new one as a replaceable part. As a result, the same drilling rod 1a and connecting rod 1b can be used for a long time, which contributes to the reduction of the construction cost.

Further, by making the maximum rotation diameter of the triangular plate piece 7 substantially equal to or smaller than the outer diameter of the drilling rod 1a, the triangle plate piece 7 further increases the diameter of the drilling hole H by the drilling rod 1a when pulling up the drilling rod 1a. It is possible to eliminate the removal of the wall surface of the well B in the expanding direction, and to keep the well H at the well diameter as originally designed.

As described above, the hydraulic solidifying material liquid replacement column construction device 1E according to this embodiment, the grip portion of the auger motor for rotating the drill rod 1a of the drill rod 1a Toko of large diameter drilling a ground for replacement column formation The connecting rod 1b having a small diameter is provided, and the connecting portion 6 between the drilling rod 1a and the connecting rod 1b is formed conically.

Thereby, the conical connection portion 6 pushes the outer diameter direction of the digging rod 1a to the position of the initial digging hole H diameter while rotating the elastic return P of the reduced diameter bored wall surface. For this reason, the original drill hole H diameter is maintained, without removing the earth and sand for the said diameter reduction in a wall surface. As a result, regardless of the pulling up of the drilling rod 1a, the soil in the drilling hole H is not placed on the connection portion 1c and is not discharged to the ground. Therefore, the soil is left as soil on the ground around the drilling hole H. It does not accumulate. In addition, there is no risk of personal injury caused by the fall of earth and sand.

  The hydraulic solidifying material liquid displacement column construction device of the present invention avoids that the drilling rod scrapes off the elastic return of the hole surface of the drilling hole when pulling up the drilling rod from the drilling hole, thereby the elastic returning portion It has the effect of being able to avoid the possibility of causing secondary disasters on excavating work due to sediment deposited on the ground and the cost of waste disposal to be eliminated before being discharged to the ground. It is useful for hydraulic solidifying material liquid displacement column construction equipment used for foundation construction methods of relatively light structures such as small scale buildings and soil slabs.

1E Hydraulic solidifying material liquid displacement column construction device 1a drilling rod 1b connecting rod 1e shoulder
4 Discharge port 6 Connection part 7 Triangular plate piece 8 Mass H Drill hole P Elastic return Q Shaved soil

Claims (2)

A hydraulic solidifying consisting of a small diameter connecting rod which is to be a grip portion of an auger motor for rotating the drilling rod above a large diameter drilling rod for drilling a region forming a hydraulic solidifying material liquid displacement column of the ground In the material liquid displacement column construction device,
A plurality of triangular plate pieces which are inclined gradually lower in height from the digging rod side to the connecting rod side are erected at predetermined intervals around the rod directly above the step portion generated between the digging rod and the connecting rod An apparatus for constructing a hydraulic-solidified material / liquid displacement column characterized in that a suitable conical connection portion is provided. The construction apparatus for a hydraulic-solidified material liquid-displacement column according to claim 1, wherein the maximum rotation diameter of the triangular plate piece is approximately equal to or less than the drilling rod rotation diameter.

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