JP7404078B2 - Construction method for connecting rods and rotating piles with tip blades - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for constructing a connecting rod and a rotary pile with tip blades.

BACKGROUND ART Conventionally, in soft ground such as clayey ground or sandy ground, a technique is known in which rotating piles are driven into the soft ground up to the hard ground to perform ground reinforcement. Here, as the piles used for ground reinforcement, concrete piles and steel pipe piles may be used. As a technique using concrete piles, for example, the techniques described in Patent Document 1 and Patent Document 2 are known.

In the technologies of Patent Document 1 and Patent Document 2, ground excavation is carried out using an excavation propulsion casing that has approximately the same length as the pile length and is provided with excavation blades for excavation on the outer periphery of the tip in the excavation direction. Once the excavation to the desired depth is completed, concrete is poured inside the casing or precast concrete piles are inserted, and the concrete piles are excavated into the ground. After construction, the excavation blade at the tip is cut off and only the casing is taken out of the soil and used for the construction of the next pile.

On the other hand, in the case of rotating piles using steel pipes, a drilling blade is fixed by welding to the outer peripheral surface of the tip of the steel pipe in the excavation direction, and the rotating pile itself is rotated by an auger motor, etc., and the rotating pile is excavated into the ground. . After construction, the excavation blades will be buried in the hard ground together with the rotating pile, and will function as an anchor to the hard ground, reinforcing the supporting strength of the rotating pile.

Patent No. 4189550 Japanese Patent Application Publication No. 2002-155530

However, with the techniques described in Patent Document 1 and Patent Document 2, it is not possible to sufficiently connect the excavation blade buried in the hard ground with the concrete pile. There is a problem that an anchor effect cannot be expected. Furthermore, in a rotating pile using a steel pipe, the rotational shearing force of an auger motor or the like must be transmitted to the excavation blade at the tip of the pile itself. For this reason, rotating piles must be manufactured using steel pipes with larger wall thickness than steel pipes that meet the design support capacity normally required for rotating piles, which increases component costs for rotating piles. There is a problem with this.

In order to solve the above-mentioned problems, the present inventors have developed a construction method for a rotary pile that includes a steel pipe body and a rotating body that is provided at the tip of the steel pipe body in the excavation direction and excavates the ground by rotating. A process of inserting the rotating shaft of the construction jig into the shaft, a process of coupling the construction jig to the rotating pile, and a process of applying a rotational shearing force to the rotating shaft while the rotating pile and the construction jig are coupled. We have devised a construction method for rotating piles that includes (Patent application 2019-063935). According to this construction method, the anchor effect of the excavation blades can be sufficiently functioned, and the cost of the members of the rotating pile can be reduced.

For example, when carrying out the above construction method, a rod is inserted into the steel pipe body as a construction jig. The rod will ultimately be about the same length as the steel pipe body, so it will be divided into parts as necessary and inserted into the steel pipe body while being connected during construction. In this case, when connecting the rods, it is necessary to first remove the rod from the auger motor of the construction machine, connect the next rod upward, and then reattach the connected rod to the auger motor. In addition to the time required for this procedure, it also requires a temporary storage area for the rods that have not yet been connected, so it cannot be said that the workability is high.

Therefore, the present invention provides a construction method for a connecting rod and a rotary pile with tip blades that can improve workability in driving steel pipe piles using a rod inserted inside the pile body as a construction jig. The purpose is to

[1] A connecting rod that can be inserted into the inside of a pile body constituting a rotary pile with tip blades, including an inner rod body and a connecting rod formed at one end of the inner rod body and connectable to a construction machine . an inner rod having one connecting portion; an outer rod body capable of storing a side of the inner rod body opposite to the first connecting portion; and a side of the outer rod body opposite to the side where the inner rod body is stored. A plurality of rods having a nested structure including an outer rod having a second connecting portion formed at the end of the pile body and connectable to a rotor with blades disposed at the tip of the pile main body, Interlocking rods that can transmit torque to each other.
[2] Between the plurality of rods, the polygonal cross section formed on the inner periphery of the end of the rod on the storage side fits into the polygonal cross section formed on the outer periphery of the end of the rod on the storage side. The connecting rod according to [1], to which torque is transmitted.
[3] The plurality of rods further includes a first intermediate rod body that can accommodate a side of the inner rod body opposite to the first connecting portion, and the outer rod body is configured to accommodate the first intermediate rod body . 1. The connecting rod according to [1] or [2], which can accommodate an intermediate rod body.
[4] First holes are formed at both ends of the inner rod body, second holes are formed at each end of the first intermediate rod body on the inner rod side, and the first intermediate rod Third holes are formed at both ends of the main body, and a fourth hole is formed at the end of the outer rod body on the first intermediate rod side, and the first hole and the second The connecting rod according to [3], further comprising a first pin inserted into one of the holes, and a second pin inserted into one of the third holes and the fourth hole. .
[5] The plurality of rods further includes a second intermediate rod having a second intermediate rod body capable of housing the first intermediate rod body, and the outer rod body is capable of housing the second intermediate rod body. The connecting rod according to [3].
[6] A method for constructing a rotary pile with tip blades using the connecting rod according to any one of [1] to [5] , comprising: connecting the first connecting portion to the construction machine; , a step of inserting the connecting rod into the inside of the pile body with the inner rod body housed in the outer rod body, and connecting the bladed rotating body to the second connecting portion; and the connecting rod. a step of transmitting torque from the construction machine to the bladed rotating body to rotate and penetrate the bladed rotating body into the ground; pulling out the inner rod body from the outer rod body; A method for constructing a rotating pile with tip blades, which includes a step of rotating a rotating body into the ground.
[7] A method for constructing a rotary pile with tip blades using the connecting rod according to any one of [1] to [5] , wherein the plurality of rods are connected to the first base of the inner rod body. The construction method further includes a first intermediate rod body having a first intermediate rod body capable of housing the side opposite to the connecting portion, the outer rod body being capable of housing the first intermediate rod body, and the construction method including a step of connecting the first connecting portion to the construction machine, storing the first intermediate rod body in the outer rod body, and connecting the connecting rod to the construction machine with the first intermediate rod body stored in the first intermediate rod body; a step of inserting the bladed rotating body into the inside of the pile main body and connecting the bladed rotating body to the second connecting portion; and transmitting torque from the construction machine to the bladed rotating body via the connecting rod to generate the bladed rotating body. A step of rotating the rotating body into the ground, pulling out the first intermediate rod body and the inner rod body housed in the first intermediate rod body from the outer rod body, and further inserting the bladed rotating body into the ground. A method for constructing a rotary pile with tip blades, comprising the steps of: rotating the pile into the ground; pulling out the inner rod body from the first intermediate rod body; and further rotating the bladed rotating body into the ground.

According to the above configuration, the connecting rods are extended by pulling out each rod body from the other rod bodies, so after first connecting the first connecting part of the inner rod to the construction machine, the connection is released. It is possible to extend the connecting rod and continue pouring without any trouble. When extending the connecting rod, the newly pulled out rod is stored inside the previously driven rod, so there is no need for a temporary storage place on the ground for the rod before connecting. Therefore, workability can be improved when driving steel pipe piles.

FIG. 2 is a side view of a connecting rod according to an embodiment of the present invention. FIG. 2 is a side view of a rotary pile with blades at the tip, in which the connecting rod shown in FIG. 1 is used as a construction jig. 2 is a view taken along the line III-III in FIG. 1. FIG. 2 is a view taken along the line IV-IV in FIG. 1. FIG. 2 is a view taken along the line VV in FIG. 1. FIG. FIG. 2 is a side view of the connecting rod shown in FIG. 1 when it is stored. 7 is a sectional view taken along the line VII-VII in FIG. 6. FIG. It is a figure showing an example of the construction method of the rotary pile concerning one embodiment of the present invention. It is a figure showing an example of the construction method of the rotary pile concerning one embodiment of the present invention. It is a figure showing an example of the construction method of the rotary pile concerning one embodiment of the present invention. It is a figure showing an example of the construction method of the rotary pile concerning one embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that, in this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals and redundant explanation will be omitted.

FIG. 1 is a side view of a connecting rod according to an embodiment of the present invention. In the illustrated example, the connecting rod 10 includes a first rod 1, a second rod 2, and a third rod 3. The first rod 1 includes a first rod body 11, a first connecting portion 12 formed at one end of the first rod body 11, and a torque transmitting portion formed at the other end of the first rod body 11. It has a structure 13. The second rod 2 has a second rod main body 21 and torque transmission structures 22A and 22B formed at both ends of the second rod main body 21, respectively. The third rod 3 includes a third rod main body 31, a torque transmission structure 32 formed at one end of the third rod main body 31, and a second connection formed at the other end of the third rod main body 31. 33.

The connecting rod 10 according to this embodiment has a nested structure in which the first rod 1 is on the inside, the second rod 2 is in the middle, and the third rod 3 is on the outside. That is, the side of the first rod body 11 opposite to the first connecting part 12 can be stored in the second rod body 21, and the second rod body 21 can be stored in the third rod body 31 from the side opposite to the second connecting part 33. It can be stored in Here, being retractable means that the outer diameter of at least a portion of one rod is smaller than the inner diameter of at least a portion of the other rod, such that one rod is at least partially contained within the other rod. It means that it is possible.

Further, each rod is formed with a hole through which a pin is inserted to maintain each rod in the housed state and the pulled out state, as will be described later. Specifically, for the pin 101A inserted between the third rod 3 and the second rod 2, a hole 34 is formed at the end of the third rod body 31 on the second rod 2 side. Holes 24A and 24B are formed at both ends of 21, respectively. In addition, holes 14A and 14B are provided at both ends of the first rod body 11 on the first rod 1 side of the second rod body 21 for the pin 101B inserted between the first rod 1 and the second rod 2. A hole 25 is formed at each end.

FIG. 2 is a side view of a rotary pile with blades at the tip, in which the connecting rod shown in FIG. 1 is used as a construction jig. In the illustrated example, the connecting rod 10 is used as a construction jig for a rotating pile with blades at the tip, which includes pile bodies 4A to 4C and a bladed rotating body 5. The pile bodies 4A-4C are connected to each other using suitable joints (not shown). As shown in the figure, when each rod is pulled out, the connecting rod 10 is inserted inside the pile bodies 4A to 4C to connect the second connecting part 33 to the connecting part 51 of the bladed rotor 5. It has a possible length. The outer diameter of the third rod body 31 is smaller than the inner diameter of the pile bodies 4A to 4C so that it can be inserted into the pile bodies 4A to 4C. As will be described later, each rod is held in an extended state using pins 101A and 101B, and is connected to the first connecting portion 12 by transmitting torque using a torque transmission structure formed at the end of each rod. Torque can be transmitted from the construction machine to the bladed rotary body 5, and the bladed rotary body 5 can be rotated and penetrated into the ground.

3 is a view taken along the line III-III in FIG. 1 (lower side of the first rod 1), and FIG. 4 is a view taken along the line IV-IV in FIG. 1 (upper side of the second rod 2). As shown in FIG. 3, the torque transmission structure 13 formed at the lower end of the first rod 1 includes a polygonal cross section 131 formed at the outer periphery of the rod. Meanwhile, as shown in FIG. 4, the torque transmission structure 22A formed at the upper end of the second rod 2 includes a polygonal cross section 221 formed on the inner circumference of the rod. The polygonal cross section 131 and the polygonal cross section 221 correspond to each other. That is, the polygonal cross section 131 and the polygonal cross section 221 are similar polygons, and the size of the polygonal cross section 131 is slightly smaller than the size of the polygonal cross section 221. As a result, the polygonal cross section 131 on the outer periphery of the lower end of the first rod 1 and the polygonal cross section 221 on the inner periphery of the upper end of the second rod 2 are fitted into each other, and between the first rod 1 and the second rod 2. It becomes possible to transmit torque. Note that although a hexagon is illustrated as an example of a polygon, other polygons such as a triangle or a quadrangle may be used.

Here, torque transmission structures 22A and 22B are formed at both ends of the second rod 2, respectively, and in this embodiment, the torque transmission structures 22A and 22B have the same structure. That is, the polygonal cross section 221 on the inner circumference of the second rod 2 that fits into the polygonal cross section 131 formed on the outer circumference of the first rod 1 as described above is formed on both the torque transmission structures 22A and 22B. . This means that when the first rod body 11 is pulled out from the second rod body 21 as shown in FIG. 2, the upper end of the second rod 2 is aligned with the torque transmission structure 13 of the first rod 1. However, when the first rod body 11 is housed in the second rod body 21, the torque transmission structure 13 of the first rod 1 is aligned with the torque transmission structure 22A of the lower end of the second rod 2. This is because it is 22B. A polygonal cross section 222 on the outer periphery of the second rod 2, which will be described next, is also formed in both the torque transmission structures 22A and 22B for the same reason.

FIG. 5 is a view taken along the line VV in FIG. 1 (above the third rod 3). As shown in FIG. 4 described above, the torque transmission structure 22B (same structure as the torque transmission structure 22A) formed at the lower end of the second rod 2 has a polygonal cross section 222 formed on the outer periphery of the rod. include. Meanwhile, as shown in FIG. 5, the torque transmission structure 32 formed at the upper end of the third rod 3 includes a polygonal cross section 321 formed at the inner circumference of the rod. The polygonal cross section 222 and the polygonal cross section 321 correspond to each other. That is, the polygonal cross-section 222 and the polygonal cross-section 321 are similar polygons, and the size of the polygonal cross-section 222 is slightly smaller than the size of the polygonal cross-section 321. As a result, the polygonal cross section 222 on the outer periphery of the lower end of the second rod 2 and the polygonal cross section 321 on the inner periphery of the upper end of the third rod 3 are fitted into each other, and between the second rod 2 and the third rod 3. It becomes possible to transmit torque. Similar to the example above, the polygon need not be the hexagon illustrated. Furthermore, the polygons of the cross sections of the outer circumference of the first rod 1 and the inner circumference of the second rod 2 are not similar to the polygons of the cross sections of the outer circumference of the second rod 2 and the inner circumference of the third rod 3. Good too. That is, for example, the former may be a quadrangle and the latter may be a hexagon.

6 is a side view of the connecting rod shown in FIG. 1 when it is stored, and FIG. 7 is a sectional view taken along the line VII-VII of FIG. 6. As shown in FIG. 6, the connecting rod 10 is constructed by storing the first rod main body 11 in the second rod main body 21 and the second rod main body 21 in the third rod main body 31. It can be shortened to the length of the main job. Pins 101A and 101B are inserted to maintain each rod in its housed and pulled out states. Specifically, when each rod is kept housed as shown in FIGS. 6 and 7, the pin 101A is inserted between the hole 34 formed at the upper end of the third rod 3 and the upper end of the second rod 2. The pin 101B is inserted into a hole 25 formed at the upper end of the second rod 2 and a hole 14A formed at the upper end of the first rod 1. On the other hand, when each rod is held in the pulled out state as described above with reference to FIG. The pin 101B is inserted into the hole 25 of the second rod 2 and the hole 14B formed at the lower end of the first rod 1.

FIGS. 8A to 8D are diagrams illustrating an example of a method for constructing a rotating pile according to an embodiment of the present invention. In FIG. 8A, (1) the connecting rod 10 is connected in a shortened state, that is, in a state in which the second rod main body 21 is stored in the third rod main body 31 and the first rod main body 11 is stored in the second rod main body 21. Step of connecting the first connecting part 12 of the type rod 10 to the auger motor 6, (2) inserting the shortened connecting type rod 10 inside the pile body 4A of the lower pile, and connecting the second connecting part 33 to the pile body 4A (3) transmitting torque from the auger motor 6 to the vaned rotating body 5 via the connecting rod 10 to the vaned rotating body 5 and the pile body 4A; and (4) after rotating and penetrating to a predetermined depth, the pin 101A described above is extracted, and the second rod body 21 and the first rod body 11 housed in the second rod body 21 are The process of pulling out the three rods from the main body 31 is shown. At this time, the third rod 3 is left in the ground together with the pile main body 4A of the lower pile and the bladed rotating body 5.

In FIG. 8B, (5) the pulled out second rod body 21 and first rod body 11 are inserted into the pile body 4B of the medium pile, and then the lower end of the second rod body 21 is inserted into the upper end of the third rod body 31. (6) inserting the pin 101A into the hole 34 and the hole 24B to fix the state in which the second rod body 21 is pulled out from the third rod body 31; (6) inserting the middle pile main body 4B into the lower pile After being connected to the pile main body 4A, torque is transmitted from the auger motor 6 to the bladed rotating body 5 via the connecting rod 10, and the bladed rotating body 5 and the pile bodies 4A, 4B are further rotated and penetrated into the ground. (7) After rotating and penetrating to a predetermined depth, the pin 101B is extracted and the first rod body 11 is pulled out from the second rod body 21; and (8) the pulled out first rod body 11 is attached to the upper pile. After inserting it into the main body 4C, the lower end of the first rod main body 11 is inserted into the upper end of the second rod main body 21, and the pin 101B is inserted into the hole 25 and the hole 14B. The process of fixing the drawn out state is shown.

In FIG. 8C, (9) the pile body 4C of the upper pile is connected to the pile body 4B of the middle pile, and torque is transmitted from the auger motor 6 to the bladed rotating body 5 via the connecting rod 10 to rotate the blades. (10) After rotating and penetrating to a predetermined depth, removing the second connecting portion 33 from the bladed rotor 5; (11) Connection (12) After fixing the position of the second rod body 21, the pin 101B is removed. A step of removing the first rod body 11, storing it in the second rod body 21, inserting the pin 101B into the hole 25 and the hole 14A, and fixing the state in which the first rod body 11 is stored in the second rod body 21 is performed. It is shown.

FIG. 8D shows (13) further pulling up the connecting rod 10 until the upper end of the third rod body 31 is above the ground, (14) fixing the position of the third rod body 31, and then removing the pin 101A; a step of storing the second rod body 21 in the third rod body 31 and inserting the pin 101A into the hole 34 and the hole 24A to fix the state in which the second rod body 21 is housed in the third rod body 31; (15) The step of further pulling up the connecting rod 10 until the lower end of the third rod main body 31 is above the ground is shown.

Through the steps described above, a rotary pile with a tip blade can be driven using the connecting rod 10. Since the connecting rod 10 is extended by pulling out the first rod body 11 from the second rod body 21 and pulling out the second rod body 21 from the third rod body 31, the first connecting portion of the first rod 1 is first expanded. After connecting the auger motor 6 to the auger motor 6, the connecting rod 10 can be extended to continue driving without breaking the connection. Since the rod newly drawn out when extending the connecting rod 10 is stored inside the previously driven rod, there is no need for a temporary storage place on the ground for the rod before connecting. In addition, the stored state and the pulled out state of each rod are fixed by inserting the pins 101A and 101B, but if the pins 101A and 101B are removed, the pulled out rod can be pulled out as is. Therefore, as shown in (4) and (7) above, the third rod 3 (and second rod 2) connected to the bladed rotating body 5 is left in the ground, and then the casting is carried out. The second rod 2 (or the first rod 1) can be easily inserted into the pile body.

In addition, in the embodiment described above, an example was explained in which the connecting rod 10 is used for driving a rotating pile with a tip blade, but the connecting rod is not limited to rotating piles, and for example, the connecting rod is used for driving a rotating pile with a tip blade. Connecting rods can also be used for press-fit piles, where the press-fit force is transmitted to the tip of the pile by means of a rod inserted inside. In the above example, the first connecting part formed on the first rod housed inside was connected to the construction machine, and the second connecting part formed on the third rod outside was connected to the tip of the pile. On the contrary, the first connecting part may be connected to the tip of the pile, and the second connecting part may be connected to the construction machine. Also, although in the above example the connecting rod includes three parts, the connecting rod may include two, or four or more parts. If the articulating rod comprises two parts, the second rod in the above example is provided with a second connection. When the connecting rod includes four or more sections, the intermediate second rod includes a plurality of rods capable of transmitting torque between each other in a nested structure.

Although preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person with ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea stated in the claims. It is understood that these also naturally fall within the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10... Connecting rod, 1... First rod, 11... First rod main body, 12... First connecting part, 13... Torque transmission structure, 14A, 14B... Hole, 2... Second rod, 21... Second rod main body , 22A, 22B... Torque transmission structure, 24A, 24B, 25... Hole, 3... Third rod, 31... Third rod body, 32... Torque transmission structure, 33... Second connecting part, 34... Hole, 101A, 101B ...Pin, 4A, 4B, 4C...Pile body, 5...Rotating body with vanes, 51...Connection part, 6...Auger motor.

Claims (7)

A connecting rod that can be inserted inside a pile body constituting a rotating pile with tip blades,
an inner rod body, and an inner rod having a first connecting portion formed at one end of the inner rod body and connectable to a construction machine ;
an outer rod body capable of accommodating the side of the inner rod body opposite to the first connecting portion; and the pile body formed at an end of the outer rod body opposite to the side where the inner rod body is housed. an outer rod having a second connection part that can be connected to a bladed rotating body disposed at the tip of the rod, and a plurality of rods having a nested structure, and capable of mutually transmitting torque between the plurality of rods. , articulating rod. Torque is transmitted between the plurality of rods by fitting the polygonal cross section formed on the inner circumference of the end of the rod on the storage side with the polygonal cross section formed on the outer circumference of the end of the rod on the storage side. The connecting rod according to claim 1. The plurality of rods further include a first intermediate rod having a first intermediate rod body capable of accommodating a side of the inner rod body opposite to the first connecting portion ,
The connecting rod according to claim 1 or 2, wherein the outer rod body can accommodate the first intermediate rod body. first holes are formed at both ends of the inner rod body;
a second hole is formed at each end of the first intermediate rod body on the inner rod side;
Third holes are formed at both ends of the first intermediate rod body, and
A fourth hole is formed at the end of the outer rod body on the first intermediate rod side,
a first pin inserted into either the first hole and the second hole; and a second pin inserted into either the third hole and the fourth hole. The connecting rod according to claim 3, comprising: The plurality of rods further include a second intermediate rod having a second intermediate rod body capable of accommodating the first intermediate rod body,
The connecting rod according to claim 3, wherein the outer rod body is capable of housing the second intermediate rod body. A method for constructing a rotary pile with tip blades using the connecting rod according to any one of claims 1 to 5, comprising:
a step of connecting the first connecting part to the construction machine;
inserting the connecting rod inside the pile body with the inner rod body housed in the outer rod body, and connecting the bladed rotating body to the second connecting portion;
transmitting torque from the construction machine to the bladed rotating body via the connecting rod to rotate and penetrate the bladed rotating body into the ground;
A method for constructing a rotary pile with blades at the tip, comprising the steps of pulling out the inner rod body from the outer rod body, and further rotating and penetrating the bladed rotor into the ground. A method for constructing a rotary pile with tip blades using the connecting rod according to any one of claims 1 to 5, comprising:
The plurality of rods further include a first intermediate rod having a first intermediate rod body capable of accommodating a side of the inner rod body opposite to the first connecting portion ,
The outer rod body can accommodate the first intermediate rod body,
The construction method includes a step of connecting the first connecting portion to the construction machine;
The first intermediate rod body is stored in the outer rod body, and the connecting rod is inserted inside the pile body with the inner rod body stored in the first intermediate rod body, and the second connecting portion is inserted into the pile body. a step of connecting the bladed rotating body to the
transmitting torque from the construction machine to the bladed rotating body via the connecting rod to rotate and penetrate the bladed rotating body into the ground;
pulling out the first intermediate rod body and the inner rod body housed in the first intermediate rod body from the outer rod body, and further rotating the bladed rotating body into the ground;
A method for constructing a rotary pile with blades at the tip, the method comprising: pulling out the inner rod body from the first intermediate rod body, and further rotating the bladed rotor into the ground.

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