JP2012092532A - Pile for soft ground reinforcement and construction method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pile for soft ground reinforcement which is a pile group including a plurality of irregularly curved piles that can be constructed by an operation from the ground only.SOLUTION: The pile (1A,1B) for the soft ground reinforcement includes a plurality of flexible curved pile parts (3a) and a base part (2) for gathering and fixing one end part of the plurality of curved pile parts (3a), and the curved pile parts (3a) are formed of a watertight cylindrical body (8) inside which a hardening material (16) can be filled.

Description

  The present invention relates to a pile for reinforcing soft ground, which is a group pile for strongly reinforcing soft ground mainly on a coast or an estuary, and a construction method thereof.

Conventionally, the ground around the shore and around the estuary has a soft layer consisting of sedimentary layers, and although it is not suitable for building buildings and structures, it is flat and has high utility value for industrial or residential use.
And in order to make it possible to construct a building or a structure with sufficient safety even in the ground having such a soft layer, several techniques relating to piles for strongly reinforcing the ground have been disclosed.

Patent Document 1 discloses a device related to a new pile that solves the problems of vibration and noise in the pile net method and problems in construction under the name of “cloth-like material reinforcing pile”.
A pile-net cloth-reinforced material pile that is a device disclosed in Patent Document 1 is a mortar or concrete pile whose outer periphery is reinforced with a cloth-like material, and at least the vicinity of the pile head is inserted into the inserted axial rebar. It is characterized by being reinforced.
According to the device disclosed in Patent Document 1, it is possible to reduce ground subsidence due to the load of the structure and lateral movement of the structure as compared with sand piles that have been used for reinforcement of soft ground having a soft layer. . In addition, in the soft ground, if there is a small hole in the soft ground, insert a cylindrical cloth material into it, press the mortar from the top and inflate it in the ground to make a pile. There is an advantage that it can be easily constructed without using a large-scale construction machine. In this case, generation of noise and vibration during construction can be reduced as compared with the conventional method.

Patent Document 2 discloses an invention related to an inexpensive foundation for supporting a large and heavy-duty steel tower under the name “steel tower foundation”.
The invention disclosed in Patent Document 2 is characterized in that a large number of piles are obliquely installed in the ground from the lower end of the main pillar material of the steel tower, and the upper ends thereof are joined and joined to the main pillar material. Is.
According to the invention disclosed in Patent Document 2 having the above-described configuration, a foundation is created by drilling an oblique hole using a small drilling machine in the ground, inserting a reinforcing bar, and injecting concrete or mortar around it. Can do. Moreover, since the invention disclosed by patent document 2 is a form in which the several slant pile was bundled, it can exhibit sufficient effect with respect to the raising force.

Patent Document 3 has the name “jacket-type underwater foundation” and is a jacket-type underwater in which a plurality of piles for fixing a jacket structure for constructing a structure such as a pier to the bottom ground are driven through the inside of the pile guide member. A basic invention is disclosed.
When the invention disclosed in Patent Document 3 is described using the reference numerals in the document as they are, a plurality of piles 8 and 9 for fixing the jacket structure 1 for constructing a building such as a bridge pier to the water bottom ground G, In the jacket-type underwater foundation that is driven through the inside of the pile guide members 5 and 6, the plate guide members 11 are respectively provided on two adjacent pile guide members (particularly, the oblique pile guide members 6) that extend substantially in parallel. The horizontal displacement suppression plate 12 is penetrated into the upper soft layer G1 of the water bottom ground G along these plate guide members so that the horizontal displacement of the jacket structure in the soft layer can be effectively suppressed. Is.
According to the invention disclosed in Patent Document 2, in a jacket-type underwater foundation in which a plurality of piles for fixing a jacket structure for constructing a structure such as a pier to the bottom floor is driven through the inside of the pile guide member, Since a plate guide member is provided on each of two adjacent pile guide members that extend substantially in parallel, and a horizontal displacement suppression plate penetrates into the upper soft layer of the water bottom ground along these plate guide members. The horizontal displacement of the jacket structure in the soft layer can be effectively suppressed, and the resistance force against the horizontal force such as an earthquake can be enhanced.

Patent Document 4 discloses a device related to a foundation construction method for a structure such as a machine or a structure under the name of “a foundation construction method for a structure”.
The idea disclosed in Patent Document 4 is to drive a short range of piles in sequence while driving over a certain range, and finally lay reinforcing bars between the heads of the piles that were driven last. The part and the reinforcing bar are embedded in the concrete layer.
According to the idea disclosed in Patent Document 4 as described above, a stable foundation can be constructed by driving a plurality of piles so as to reach the hard layer beyond the soft layer in the ground while sequentially adding piles.

Patent Document 5 discloses an invention relating to a method for constructing a steel pipe slanting guillotine in soft ground under the name “construction method of a steel pipe slanting guilloid on soft ground”.
In the invention disclosed in Patent Document 5, a required number of quies are driven vertically toward the soft ground, and appropriate angles are provided on the left and right sides of the vertical quies so as to have a required angle with respect to the vertical lower direction. The slanted guillo is driven so that its lower end penetrates into the support layer, and then the tops of the slanted guilloids that have been driven in are tightened inward from each other so that the part embedded in the soft layer of the slanted guillois is footed outward. After bending and applying an amount of moment corresponding to the static load due to earth pressure applied to the slanted guillotine due to consolidation settlement expected on the ground, the vertical guy, the double-sided slanted guillo and the vertical gui In addition, footing concrete is placed on the protruding portions at both ends of the both side slanted gui and the upper ends of the respective quizzes are fixed.
According to the invention disclosed in Patent Document 5 as described above, a moment corresponding to the amount of ground subsidence in the soft ground layer can be given to the slanted guillo in advance. Even if ground subsidence occurs after the construction, it is possible to prevent the slanting guilloche from being bent inside the footing as in the conventional construction method. In addition, this makes it possible to remove the instability of slanted guillotes caused by ground subsidence and to exert the maximum ground reinforcement effect with the minimum number of slanted squirrels.

Japanese Utility Model Publication No. 61-76832 JP-A-48-69307 JP 2004-44115 A JP-A-50-114808 Japanese Patent Publication No. 48-6207

  Patent Document 1 discloses a technique related to a pile in which a steel bag and mortar or concrete are accommodated in a cylindrical bag body, but a technique for irregularly meandering and arranging this pile in a soft layer. The content is not disclosed or suggested or referred to at all.

  Although the technical content regarding the group pile made from a reinforced concrete is disclosed by patent document 2, the technical content which makes the diagonal pile which comprises a group pile meander irregularly in the ground is not disclosed at all.

  Patent Document 3 discloses a technical content related to a slant pile penetrating the soft ground into the water bottom ground, and the slant pile is arranged in a state of irregularly meandering in the soft ground. No technical content is disclosed.

  Although the technical content regarding the pile arrange | positioned in the state bent in the ground is disclosed by patent document 4, this pile consists of steel materials and is not made to bend intentionally. Therefore, Patent Document 4 also does not disclose any technical contents for arranging the reinforced concrete piles to meander irregularly in the ground.

  Patent Document 5 discloses the technical content of pre-curving steel slanted guillows, but it discloses nothing about the technical content of irregularly meandering and arranging reinforced concrete piles in the ground. It has not been.

Generally, it is known that the larger the contact area between the pile and the soil in the ground, the greater the pulling resistance of the pile and the higher the reinforcement effect of the ground. However, as in the past, placing the pile into the ground from the ground As long as the construction method was adopted, it was not realistic to arrange a group pile in the ground that was a bundle of randomly reinforced concrete piles.
On the other hand, once the soft ground is dug up, a huge hole is drilled in the ground, and the group pile made up of reinforced concrete piles that meander irregularly is housed in the hole and backfilled again, the bent pile is bundled. However, this method is not practical from the viewpoint of cost-effectiveness because it is very time-consuming.

  The present invention has been made in response to such a conventional situation, and can be easily constructed only from the ground without digging up the ground, and is formed by bundling curved piles that meander irregularly in the ground. It is providing the pile for soft ground reinforcement which is a group pile, and its construction method.

In order to achieve the above object, the soft ground reinforcing pile according to the first aspect of the present invention collects and fixes a plurality of flexible pile portions and one end of the plurality of bent pile portions. The curved pile portion is formed of a cylindrical body having water-tightness that can be filled with a hardening material.
In the invention of the above configuration, the curved pile portion is arranged in an irregularly bent (meandering) state in the ground (mainly soft layer), thereby increasing the contact resistance with the ground and making it difficult to come off. Have Moreover, a base has the effect | action of becoming a foundation of a structure by gathering and fixing a curved pile part and exposing the one part on the ground.
In other words, in the invention according to claim 1, a curved foundation that bends irregularly like a tree root around the base is disposed in the ground, so that the soft layer is strongly reinforced and a highly stable foundation is provided. It has the effect of providing.
In addition, the curved pile portion is formed into a cylindrical body having water-tightness that can be filled with a hardener, so that the cylindrical body is first disposed in the ground without being filled with a filler, and then the cylindrical body. By filling the body with a hardener, it is possible to install a bent pile bent irregularly without digging the ground and drilling holes.

The pile for reinforcing soft ground according to claim 2 is the pile for reinforcing soft ground according to claim 1, and has at least one straight pile portion, and the base portion has at least one straight pile portion. And one end part of a plurality of curved pile parts is assembled and fixed.
The invention having the above-described configuration has the same function as that of the first aspect of the invention. Moreover, compared with the case where all piles are curved piles, a straight pile (which is a concept including slant piles) has an effect of facilitating its construction.

The pile for reinforcing soft ground according to claim 3 is the pile for reinforcing soft ground according to claim 1 or claim 2, wherein the other end portion on the side not fixed to the base of the plurality of curved pile portions is A drill for propelling by propelling itself in the soft layer is provided.
In the invention of the above configuration, in addition to the same action as that of the invention described in claim 1 or 2, the drill self-propels and propels in the ground (particularly the soft layer), and the cylinder is disposed in the passage. It has the effect of making it possible. Thereby, it has the effect | action of enabling arrangement | positioning of the curved pile which irregularly bent, without digging up the ground.

The construction method of the pile for reinforcing soft ground according to the invention of claim 4 drives the drill of the pile for reinforcing soft ground according to claim 3 to propel the curved pile portion into the soft layer, A first step of arranging the cylindrical body in the soft layer while being irregularly bent by the direction changing device, and after this first step, filling the cylindrical body provided in the soft layer with a hardening material. And a second step of curing to form a pile.
In the invention having the above-described configuration, the first step has an effect that the cylinder is disposed in the ground (particularly the soft layer) in an irregularly bent state only by an operation from the ground without digging up the ground.
The subsequent second step is an effect of forming a curved pile irregularly bent in the ground by filling and hardening the cylinder disposed in the ground in the first step. Have
Therefore, it has the effect | action of arrange | positioning the curved pile bent in arbitrary shapes in the ground, without dug up the ground by having the said 1st and 2nd process.

The method for constructing a pile for reinforcing soft ground according to claim 5 is characterized in that, in the first step, the traveling direction of the drill is determined by remote operation from the ground. Pile construction method.
In addition to the same effect as that of the invention according to claim 4, the invention of the above configuration increases the degree of freedom of the layout of the curved pile by determining the traveling direction of the drill in the first step by remote operation from the ground. Has an effect.

According to invention of Claim 1 of this invention, a group pile like the root of a tree formed by bundling a plurality of curved pile parts can be provided. In this case, since the contact resistance between the individual piles (curved pile portions) and the ground can be greatly increased, it is possible to exert a higher ground reinforcement effect than when using a group pile composed of straight piles. .
In addition, when forming the curved pile part, only the operation (work) from the ground without digging up the ground is made by filling the hardened material into a flexible and watertight cylinder and hardening it. It is possible to arrange curved piles that are irregularly bent in the ground.
That is, according to the first aspect of the present invention, it is possible to provide a group pile having a novel form that has not been conventionally provided, and to firmly reinforce the soft ground, and to facilitate the construction thereof.

  Since invention of Claim 2 makes a part of the pile which comprises a group pile a straight pile (it is a concept containing a diagonal pile), since the construction method of the conventional straight pile can also be used together, a group The construction can be facilitated as compared with the case where all the pile portions constituting the pile are constituted by curved piles. Thereby, while shortening a construction period, construction cost can also be reduced.

  In addition to the same effect as that of the invention described in claim 1 or 2, the invention described in claim 3 is provided with a drill at the other end on the side not fixed to the base of the curved pile portion, so that Running and propelling can form an irregularly bent slot in the ground. And by arrange | positioning a cylinder to this elongate hole, the curved pile which bent irregularly can be arrange | positioned, without digging up the ground. Therefore, the soft ground reinforcing pile according to claim 3 can be constructed only by an operation (work) from the ground.

According to invention of Claim 4, a curved pile can be arrange | positioned in the ground, without digging up the ground. As a result, construction of a group pile having a plurality of curved piles can be facilitated, and the construction cost can be reduced.
The effect of the soft ground reinforcing pile constructed according to the invention of claim 4 is the same as that of the invention of claim 3.

In addition to the same effect as that of the invention of the fourth aspect, the invention according to the fifth aspect can determine the traveling direction of the drill by remote control from the ground, so that the degree of freedom of the layout of the curved pile can be increased. .
More specifically, if the drill cannot reach the obstacle (for example, rocks) in the ground at the time of construction and can not follow the planned course, the course that avoids this obstacle from the ground part is selected. Can be set.
As a result, it becomes easy to avoid a construction error or a situation where construction cannot be performed, and a construction method for a soft ground reinforcing pile with higher versatility can be provided.

It is a conceptual diagram of the pile for soft ground reinforcement which concerns on Example 1 of this invention. It is a fragmentary figure of the pile for soft ground reinforcement which concerns on Example 1 of this invention. (A)-(c) is a cross-sectional conceptual diagram which shows the procedure for arrange | positioning the curved pile of the soft ground reinforcement pile which concerns on Example 1 in all in the ground. It is a conceptual diagram which shows the construction state of the pile for soft ground reinforcement which concerns on Example 1 of this invention. It is a conceptual diagram which shows the construction state of the pile for soft ground reinforcement which concerns on Example 2 of this invention.

A soft ground reinforcing pile according to Embodiment 1 of the present invention will be described in detail with reference to FIGS. 1 to 3.
First, the form of the soft ground reinforcing pile according to the first embodiment will be described with reference to FIG. FIG. 1 is a conceptual diagram of a soft ground reinforcing pile according to Embodiment 1 of the present invention.
As shown in FIG. 1, the soft ground reinforcing pile 1A according to the first embodiment is a group pile in which a plurality of pile portions 3 are arranged in the ground like a tree root from the base portion 2, and in particular, the pile The part 3 includes a curved pile 3a disposed in an irregularly bent state in the ground (mainly in the soft layer).
Further, the bent pile 3a is provided with a drill 4 at the other end of the cylindrical body 8 made of a material having flexibility and water tightness, which is not fixed to the base 2. The drill 4 is propelled in the ground so that the cylindrical body 8 connected to the drill 4 is disposed in a state of being irregularly meandered (curved) in the ground, and then the ground. The curved pile 3a is formed by filling and curing, for example, mortar, concrete, synthetic resin, or the like as a hardener in the hollow portion from the end portion of the cylindrical body 8 arranged in the above. In addition, the detail of the formation method of the curved pile 3a is demonstrated in a back | latter stage.
Moreover, although all the pile parts 3 of the pile 1A for soft ground reinforcement which concerns on Example 1 may be comprised by the above-mentioned curved pile 3a, at least one part of the pile part 3 consists of steel materials 14, for example. You may comprise by the straight pile 3b (it is a concept containing a diagonal pile). In this case, it is not always necessary to provide the drill 4 at the end of the steel material 14.

According to the soft ground reinforcing pile 1A according to the first embodiment, by exposing at least a part of the upper portion of the base 2 from the ground, it can be used as a foundation of a building or a structure. For this reason, the base 2 is preferably made of metal or reinforced concrete.
Moreover, since the pile part 3 extended in the ground like the root of the tree from the base part 2 is provided with a plurality of curved piles 3a, the pulling resistance from the ground is increased as compared with a conventional group pile consisting only of straight piles. be able to. Thereby, the soft ground can be strongly reinforced by the soft ground reinforcing pile 1A according to the first embodiment.

Here, the curved pile 3a of the soft ground reinforcing pile 1A according to the first embodiment will be described in detail with reference to FIG.
FIG. 2 is a partial view of the pile for reinforcing soft ground according to the first embodiment of the present invention. In addition, the same code | symbol is attached | subjected about the part same as what was described in FIG. 1, and the description about the structure is abbreviate | omitted.
The curved pile 3a of the soft ground reinforcing pile 1A according to the first embodiment is provided with a drill 4 at the other end of the cylindrical body 8 having flexibility and water tightness that is not fixed to the base 2 (not shown). The motor 6 and the speed reducer 7 for driving the drill 4 are provided inside the other end of the cylindrical body 8 and are connected to the motor 6 from the ground through the cylindrical body 8 by a power transmission cable 9. Power is supplied to 6 and the drill 4 is driven.
Further, when the motor 6 is driven, the torque of the motor 6 is decelerated by the speed reducer 7 and transmitted to the drill 4, whereby a large torque is generated in the drill 4. And this drill 4 carries out the self-propelled propulsion in the ground which is not shown in figure, and the cylinder 8 connected to the drill 4 will be necessarily arrange | positioned on the channel | path, As a result, a cylinder in the ground The body 8 is arranged in an irregularly bent state.
In the first embodiment, the drive mechanism 5 includes a combination of the motor 6 and the speed reducer 7.

Here, with reference to FIG. 3, a method of arranging the curved piles in the ground will be described in detail. Here, the case where the curved pile is disposed in the ground where the soft layer is formed on the support base will be described as an example.
FIGS. 3A to 3C are cross-sectional conceptual diagrams showing a procedure for disposing the curved pile of the soft ground reinforcing pile according to the first embodiment in the ground. In addition, the same code | symbol is attached | subjected about the same part as what was described in FIG. 1 or FIG. 2, and the description about the structure is abbreviate | omitted.
In order to arrange the curved pile 3a of the soft ground reinforcing pile 1A according to the first embodiment in the ground, first, as shown in FIG. The drill 4 is driven to rotate, and the drill 4 is self-propelled and propelled in the soft layer 12 to form a long hole 15 for receiving the cylindrical body 8, and the cylindrical body 8 is received in the long hole 15. (Step S1).

Although not shown in particular, the drive mechanism 5 of the curved pile 3a is provided with a direction changing device for changing the traveling direction of the drill 4, for example, by remote operation using an electric signal or the like from the ground 11 The drill 4 can be propelled and propelled in the intended direction. By providing such a direction changing device in the drive mechanism 5, the drill 4 is propelled to a target depth and direction, and the cylinder 8 is bent into the shape intended by the installer (meandered) in the ground. Can be arranged.
Moreover, the reinforcement effect of the soft layer 12 by the curved pile 3a can be made still stronger by making the drill 4 of the curved pile 3a reach the support ground 13 beyond the soft layer 12 in the ground.
In addition, as a specific example of the direction change device, the drill 4 and the speed reducer 7 or the electric drive type having a structure in which the rotation shaft of the motor 6 is inclined by the combination of the motor and the gear, or the drill 4 by the tension of the wire. A mechanical device having a structure for changing the direction of the speed reducer 7 or the motor 6 is conceivable. However, it is sufficiently possible to provide the device itself by a known technique at the time of filing the present application.
In the first embodiment, the case where the motor 6 of the drive mechanism 5 is driven by electric power is described as an example. However, the motor 6 is configured to be driven using fluid such as hydraulic power or compressed air. May be. In this case, the power transmission cable 9 needs to be a supply pipe for supplying the fluid as described above.
Moreover, you may comprise so that the fluid utilized for the drive of the motor 6 can be temporarily filled in the cylinder 8 at this time. In this case, it is possible to prevent the cylinder 8 from being crushed by earth pressure when the drill 4 is propelled and propelled to dispose the cylinder 8 in the ground.

Returning to the description of FIG. 3 again, after completing the above-described step S1, as shown in FIG. 3B, the connection between the speed reducer 7 and the motor 6 is released, for example, by an external operation, and the cylinder The motor 6 and the power transmission cable 9 are taken out from the body 8 (step S2). In FIG. 3, the case where the speed reducer 7 is left in the cylinder 8 is described as an example. However, the drill 4 and the speed reducer 7 can be separated from each other, and the cylinder in the above step S <b> 2. The speed reducer 7, the motor 6, and the power transmission cable 9 may be removed from the body 8.
There is no particular merit of leaving the speed reducer 7 in the cylinder 8, but when the structure for enabling the connection structure of the drill 4 and the speed reducer 7 to be separated becomes complicated, the speed reducer 7 is replaced with the cylinder 8. By leaving it inside, the manufacturing cost can be reduced. Of course, the same applies to the direction changing device. That is, it is desirable to take out from the cylinder 8, but it may be left in the cylinder 8 if the manufacturing cost can be reduced by leaving it.

And after this step S2, if necessary, at least one flexible wire 10 is inserted into the hollow part of the cylinder 8, and further, for example, concrete or mortar, What is necessary is just to fill and harden the hardening materials 16, such as a synthetic resin, (step S3).
Although not particularly shown in FIG. 3, the cylindrical body 8 is separately provided with a flexible reinforcing wire 10 on the inner side or the thickness portion thereof, and the cylindrical body 8 is inserted into the elongated hole 15. Even in this case, the outer shape of the cylindrical body 8 can be maintained. As such a cylindrical body 8, for example, a bellows-like one in which the flexible wire 1 is wound in a coil shape and the gap is covered with a synthetic resin may be used.
Further, for example, waste tires cut into chips may be dispersed and mixed in the hardener 16 filled in the cylinder 8. In this case, for example, by using a resin as the curing material 16, the curved pile 3a filled with the curing material 16 and cured can be made flexible and conventionally used as industrial waste. Waste tires that have no utility value can be used effectively. Furthermore, the construction cost of the soft ground reinforcing pile 1A according to the first embodiment can be significantly reduced by replacing most of the resin as the hardened material 16 with chip-shaped waste tires.

According to the procedure described in Steps S1 to S3 as described above, the irregularly meandering curved pile 3a is arranged in the ground without dug up the ground only by operation (work) from the ground. Can be set.
Further, when arranging a plurality of curved piles 3a in the ground, it is only necessary to repeat the steps S1 to S3, or the above steps S1 to S3 are simultaneously performed at a plurality of locations. Therefore, the soft ground reinforcing pile 1A, which is a group pile including a plurality of curved piles 3a, can be easily constructed, and its cost can be reduced.
In addition, when the soft layer 12 which arrange | positions the curved pile 3a contains many water | moisture contents, the curved pile 3a after construction is used by using the lightweight concrete etc. whose specific gravity is 1-0.7 as the hardening | curing material 16, for example. Sedimentation in the soft layer 12 due to the load can be prevented.

In addition, the curved pile 3a is arranged according to the procedure as described above, and if necessary, at least one straight pile 3b (concept including a slant pile) is driven by a conventionally known method, or The part where the drill 4 of the curved pile 3a is self-propelled and propelled vertically downward when performing the steps S1 to S3 described above to form the straight pile 3b, and the ends of the curved pile 3a and the straight pile 3b on the ground 11 side are gathered Is tightened with a reinforcing bar or the like as necessary, and fixed, for example, with concrete or the like, or an end disposed on the ground 11 side of the pile portion 3 using steel or the like for a metal base body By forming the base portion 2 by tightening the portion (step S4), the soft ground reinforcing pile 1A according to the first embodiment is obtained.
In addition, the base 2 of the pile 1A for soft ground reinforcement which concerns on Example 1 is used as a foundation of a building or a structure. In this case, the risk of damage and collapse of buildings and structures due to earthquakes and natural phenomena can be greatly reduced.

FIG. 4 shows a state in the ground of the soft ground reinforcing pile 1A constructed according to the procedure as described above.
FIG. 4 is a conceptual diagram showing a construction state of the pile for reinforcing soft ground according to the first embodiment of the present invention. The same parts as those described in FIGS. 1 to 3 are denoted by the same reference numerals, and description of the configuration is omitted. FIG. 4 shows an example in which only one soft ground reinforcing pile 1A is constructed on the ground having the soft layer 12, but a plurality of soft ground reinforcing piles 1A are provided next to the ground. By doing so, the soft ground of a fixed area | region can be strengthened firmly.
As shown in FIG. 4, the soft ground reinforcing pile 1A according to the first embodiment is such that the curved pile 3a mainly meanders irregularly in the soft layer 12 and radiates around the base 2 as if it is a tree root. It is arranged. Moreover, although the case where the straight pile 3b is driven vertically in the ground is described as an example in FIG. 4, the straight pile 3b may be a slant pile. In any case, it is desirable that the direct pile 3b penetrates the soft layer 12 and reaches the support ground 13.
Moreover, the reinforcement effect of the soft layer 12 by the soft ground reinforcement pile 1A according to Example 1 is further enhanced by allowing at least some of the curved piles 3a to reach not only the soft layer 12 but also the supporting ground 13. Can do.
According to the pile 1A for soft ground reinforcement according to the first embodiment, a plurality of bent piles 3a are mainly disposed in the soft layer 12, and the bent pile 3a has a resistance to pulling out from the ground 3b. Therefore, it is possible to reinforce the soft layer 12 more firmly than in the case of using a group pile composed only of the straight piles 3b. Therefore, a foundation excellent in load resistance and earthquake resistance can be provided. Moreover, the area where the soft ground reinforcement pile 1A is constructed, such as a mangrove forest that grows in the vicinity of the coast, can be protected from damage caused by waves and earthquakes.

  Moreover, by adopting steps S1 to S3 as described above as a construction method of the curved pile 3a, the curved pile 3a is disposed in the ground without digging up the ground only by an operation (work) from the ground portion. Can do. As a result, the construction of the soft ground reinforcing pile 1A according to the first embodiment can be facilitated and the spread thereof can be promoted.

The soft ground reinforcement pile according to the second embodiment will be described in detail with reference to FIG.
FIG. 5: is a conceptual diagram which shows the construction state of the pile for soft ground reinforcement which concerns on Example 2 of this invention. The same parts as those described in FIGS. 1 to 4 are denoted by the same reference numerals, and description of the configuration is omitted.
The soft ground reinforcement pile 1B according to the second embodiment has the same configuration as the soft ground reinforcement pile 1A according to the first embodiment described above, and includes a plurality of straight piles 3b, and the straight piles 3b are inclined piles. is there.
Generally, the resistance to pulling out from the ground is greater when the pile is placed diagonally than when the straight pile is placed vertically in the ground. In addition, the reinforcement effect of the soft layer 12 can be further enhanced by placing a plurality of oblique piles having a large pulling resistance. Moreover, although the curved pile 3a can be constructed only by the operation from the ground, when all the pile portions 3 are the curved pile 3a, the construction is performed when constructing a group pile composed of an assembly of oblique piles. Compared to this, it becomes complicated.
For this reason, in the pile 1B for soft ground reinforcement which concerns on Example 2, replacing the part of the pile part 3 which comprises a group pile with a diagonal pile, fully exhibiting the reinforcement effect of the soft layer 12, Construction can be facilitated.
Moreover, also in the soft ground reinforcing pile 1B according to the second embodiment, it is desirable that all of the straight piles 3b and some of the curved piles 3a reach the support ground 13 beyond the soft layer 12. .
Thus, the reinforcement effect of the soft layer 12 can be heightened by making the other end part (drill 4) of the side which is not fixed to the base 2 of the pile part 3 reach the support ground 13.

In addition, the cylinder 8 which comprises the curved pile 3a of the soft ground reinforcement piles 1A and 1B according to Examples 1 and 2 is made of synthetic resin, rubber, non-woven fabric, woven fabric, or at least two of these. (For example, a woven fabric surface coated with a synthetic resin). That is, the material constituting the cylindrical body 8 is flexible so that it can be bent irregularly in the ground, and when the hardening material 16 is filled, the hardening material 16 hardly leaks to the outside, and is durable. Any material may be used as long as it has a property.
Moreover, you may use what processed the waste tire as the cylinder 8. As shown in FIG. In this case, industrial waste can be used effectively.

According to the piles 1A and 1B for soft ground reinforcement according to the first and second embodiments as described above, the ground having a soft layer near the coast or the estuary can be strongly reinforced and effectively used. Moreover, since the soft ground reinforcing piles 1A and 1B can be used as a foundation for a bridge pier or the like, it is possible to provide a building or structure having sufficient resistance against a natural disaster such as an earthquake.
Further, the soft ground reinforcing pile 1A according to the first embodiment and the soft ground reinforcing pile 1B according to the first embodiment or the soft ground reinforcing pile 1B according to the first embodiment are combined. The reinforcing pile 1B may be used in combination with a conventionally known direct resistance, oblique pile or group pile. In this case, it is possible to simultaneously achieve a sufficient reinforcing effect for the soft ground and a reduction in construction cost.

  As described above, the present invention is a soft ground reinforcing pile that is a group pile including a plurality of irregularly bent piles that can be constructed only by operation from the ground, and a construction method thereof. It can be used in the field of civil engineering.

DESCRIPTION OF SYMBOLS 1A, 1B ... Pile for soft ground reinforcement 2 ... Base part 3 ... Pile part 3a ... Curve pile 3b ... Straight pile 4 ... Drill 5 ... Drive mechanism 6 ... Motor 7 ... Reducer 8 ... Cylindrical body 9 ... Power transmission cable 10 ... Wire DESCRIPTION OF SYMBOLS 11 ... Above-ground 12 ... Soft layer 13 ... Support ground 14 ... Steel material 15 ... Long hole 16 ... Hardening material

Claims (5)

A plurality of curved pile portions having flexibility, and a base portion that collects and fixes one end of the plurality of curved pile portions;
The curved pile portion is formed of a cylindrical body having water-tightness capable of being filled with a hardening material, and a soft ground reinforcing pile.   2. The apparatus according to claim 1, further comprising at least one straight pile portion, wherein the base portion collects and fixes one end portion of the at least one straight pile portion and the plurality of curved pile portions. Pile for soft ground reinforcement.   The other end of the side of the plurality of curved piles not fixed to the base includes a drill for self-propelled propulsion in the soft layer. Pile for ground reinforcement. While driving the drill of the soft ground reinforcement pile according to claim 3 to propel the curved pile portion into the soft layer and bending the tube body irregularly in the soft layer by the direction changing device. A first step of disposing;
A soft ground reinforcing pile comprising: a second step after the first step, comprising: a second step of filling the cylindrical body disposed in the soft layer with a hardening material and curing it into a pile. Construction method.   5. The method for constructing a pile for reinforcing soft ground according to claim 4, wherein in the first step, the traveling direction of the drill is determined by remote control from the ground.