JP4986799B2 - Embedded pile method using both earth drill and pile driver - Google Patents

Description

  The present invention relates to an embedded pile method, and more particularly to a pre-boring rooting method using a ground drill machine and a pile driving machine in combination with a construction machine.

  As one of the embedded pile methods, a pre-boring rooting method is known. In this construction method, a three-point support pile driver equipped with an auger drive device is generally used as a construction machine. Construction is carried out by excavating to a predetermined depth with an earth auger driven by an auger drive device, and after excavation, root hardening liquid and pile surrounding filling liquid are injected into the excavation hole from the tip of the auger and mixed with the excavated sediment and mixed. The procedure is to build a ready-made pile and press fit it.

  In the conventional construction method described above, since the three-point support pile driving machine does not have a crane function, it is necessary to use a companion crane that has been separately carried into the construction site for the construction of a ready-made pile. On the other hand, since the companion crane does not have a function of rotationally press-fitting ready-made piles, a three-point supported pile driver must be used again for rotational press-fitting after the ready-made piles are built.

  For this reason, during the construction work of ready-made piles, the three-point pile driver has to wait in its place, or if the next pile to be constructed is excavated, It is necessary to return to the place of the pile that was interrupted and completed the construction. That is, the conventional construction method has a problem that the construction efficiency is not good while using at least two heavy machines.

  Further, in the conventional construction method, excavation is performed only by the earth auger equipped in the three-point pile driver, and the excavated soil is hardly discharged. For this reason, more soil cement than necessary is formed in the excavation hole, and there is also a problem that the soil cement overflows due to embedding of the ready-made piles and industrial waste is generated.

The prior art information related to the invention of this application is as follows. Non-Patent Document 1 describes a general pre-boring rooting method using a three-point pile driver. In the same document, a cast-in-place pile method using an earth drill is described.
Satoshi Nakamura and Shinji Naito, “New Construction Series Vol. 2, Basics Rooted in the Earth”, Sankaido Co., Ltd., January 1994, p. 56-57, p. 106-107

The present invention has been made based on the technical background as described above, and achieves the following object.
An object of the present invention is to provide an embedded pile method capable of improving construction efficiency by using another construction machine instead of a companion crane.

  Another object of the present invention is to provide an embedded pile construction method in which industrial waste is not generated by erection of ready-made piles.

  The inventor of the present invention has made extensive studies in order to solve the above problems, and has focused on an earth drill machine known as a cast-in-place pile construction machine. The earth drill machine includes a kelly bar that applies a rotational force and a pushing force to the excavation bucket, and has a crane function using an auxiliary hoisting rope. Therefore, in the embedding method of ready-made piles, if the process of building ready-made piles and the subsequent rotary press-fitting process are carried out with an earth drill machine, the pile driver does not wait or return from the place where the next pile should be constructed. , Can do the required work. Moreover, it is possible to prevent the soil cement from overflowing due to the embedding of the ready-made pile by performing excavation by the excavation bucket of the earth drill machine and discharging the soil.

The present invention is based on the above knowledge and employs the following means.
That is, the present invention includes a revolving structure, a boom and a front arm equipped on the revolving structure, a hoisting rope and an auxiliary hoisting rope that hang from the tip of the boom, a kelly bar supported by the hoisting rope, and the front arm. An earth drill machine provided with a kelly bar driving device that is provided on the kelly bar and applies a rotational force and a pushing force to the kelly bar;
Pile driver comprising a revolving body, a leader equipped on the revolving body, an auger drive device provided on the leader so as to be movable up and down, and an auger screw attached to the auger drive device and having an excavation head at the tip It is in the embedded pile construction method using an earth drill machine and a pile driver characterized by performing the following processes using a machine.
a. Connecting a bucket to the kelly bar of the earth drill machine, and excavating and excavating the ground surface layer part to a predetermined depth b. A main drilling from the bottom of the preceding drilling hole to a predetermined depth by an auger screw of the pile driver c. Supplying root-setting liquid into the auger screw and injecting the root-setting liquid from the excavation head over a predetermined depth range above the bottom of the excavation hole; d. Elevating and lowering the auger screw to repeatedly stir up and down excavated earth and sand and mix with the root hardening liquid to form a root hardening part e. Pulling up the auger screw to above the root consolidation part, supplying pile circumference filling liquid into the auger screw, and extending the pile circumference filling liquid from the excavation head over a predetermined depth range above the root consolidation part. Injecting step f. Elevating and lowering the auger screw to repeatedly agitate the excavated earth and sand and mix with the pile circumference filling liquid to form a pile circumference fixing part g. Hung a ready-made pile by the auxiliary hoisting rope of the earth drill machine, and inserting the ready-made pile into the main excavation hole h. A step of connecting the upper end of the ready-made pile to the kelly bar and rotationally press-fitting the ready-made pile to a predetermined depth

In the above method,
i. You may make it provide the process of suspending a casing with the said supplementary hoisting rope and building this casing in the said preceding excavation hole.

  According to the present invention, each process of the embedded pile construction method can be shared by the ground drill machine and the pile driving machine, and can be effectively used without playing these construction machines. Therefore, the construction efficiency can be improved. . In addition, by excavating and excavating as in the case of the earth drill method, it is possible to prevent the soil cement rising from the excavation hole from overflowing and to suppress the generation of industrial waste.

  Embodiments of the present invention will be described below with reference to the drawings. In the present invention, a well-known general machine is used for both the earth drill machine and the pile driving machine. First, the schematic structure thereof will be described. 1 and 2 show an earth drill machine 1, FIG. 1 shows an excavation posture, and FIG. 2 shows a supplementary crane posture. A revolving unit 3 is mounted on the crawler traveling unit 2, and the revolving unit 3 includes a boom 4 and a front arm 5. The boom 4 is a lattice assembly and can be raised and lowered freely by a raising and lowering wire 6. The boom 4 includes a telescopic type and a reader type. A hoisting rope 7 fed out by a hoisting winch is suspended from the pulley 8 at the tip of the boom 4, and a kelly bar 9 is supported on the hoisting rope 7. In addition to the hoisting rope 7, the earth drill machine 1 has an auxiliary hoisting rope 32 that is fed out by an auxiliary winding winch.

  The front arm 5 is provided up and down by a hydraulic cylinder 10. At the front end of the front arm 5, a Keriba driving device 11 is provided. The keriba driving device 11 has a frame 12 supported by the front arm 5, and a rotational driving device 13 is provided on the frame 12. The rotary drive device 13 is of a rotary table type, and is used for fitting the kelly bar 9 so that it can be raised and lowered and not relatively rotatable so as to apply a rotational force to the kelly bar 9. Further, the frame 12 is provided with a pushing device 14 composed of a hydraulic cylinder for applying a pushing force to the kelly bar 9.

  FIG. 3 shows a three-point support type pile driving machine 20, in which a turning body 22 is mounted on a crawler traveling body 21, and the turning body 22 includes a leader 23 that can be raised and lowered. Two backstays 24 having a built-in cylinder are connected to the leader 23, and the backstay 24 supports the leader 23 from the rear when standing up.

  The leader 23 is provided with an auger drive device 25 that can be moved up and down along the leader. An auger screw 27 provided with an excavation head (auger head) 26 is connected to the auger drive device 25, and the auger screw 27 is given a rotational force and a pushing force to the ground by the auger drive device 25. The auger screw 27 is supplied with a drilling liquid, a root hardening liquid, and a pile circumference filling liquid by a supply system (not shown), and these liquids are poured out from the drilling head 26.

Next, an embodiment of the inventive construction method using the earth drill machine and the pile driving machine will be described.
1. Pile hole excavation (see Fig. 4)
(1) Pile core set The ground drill machine 1 is used for preceding excavation. Similar to the conventional earth drill method, the core of the Keriba 9 is matched with the pile core bar 30. In addition, the vertical accuracy of the Keriba 9 is confirmed from two directions by swinging down.

(2) Precise excavation The excavation bucket 31 having the same diameter as the casing (mouth pipe) to be built in the next process is set at the lower end of the kelly bar 9, and the surface layer part is excavated while discharging.

(3) Casing construction The kelly bar 9 is pulled toward the boom 4, the casing 33 is suspended by the auxiliary winding rope 32, and this casing 33 is installed in the preceding excavation hole 34. The diameter of the casing 33 is determined in consideration of the pile diameter (node diameter) of a ready-made pile built in a later process. After the casing 33 is built, the preceding excavation hole 34 is further dug down and the soil is discharged. At this time, when it is difficult to dig due to the formation, a stabilizer such as bentonite is used in combination. The digging hole 34a indicated by the chain line in the figure has substantially the same diameter as the main digging hole excavated in a later process, and the amount of soil discharged by the digging hole 34a takes into account the amount of soil cement produced in the later process. The amount of soil cement will not overflow into the pile heads of ready-made piles.

(4) Main drilling The pile driver 20 is used for the main drilling. That is, excavation is started from the bottom of the digging hole 34a by pushing the auger screw 27 into the ground while rotating the auger screw 27 by the auger driving device 25. Depending on the type of formation, excavation water may be supplied to the auger screw 27 and excavated while being injected from the excavation head 26.
(5) Completion of excavation After excavation to a predetermined depth, the excavation is completed.

2. Established root-fixed part and pile circumference fixing part (see Fig. 5)
(6) Root hardening liquid injection The pile driving machine 20 is used as it is for the construction of the root hardening part and the pile periphery fixing part following the main excavation. That is, when the drilling fluid is used, the fluid supplied to the auger screw 27 is switched to the rooting fluid, and this rooting fluid is injected into the drilling hole from the drilling head 26. The root-setting liquid is injected over a predetermined depth range from the bottom of the excavation hole while rotating the auger screw 27 upward. As this root hardening liquid, cement milk having a predetermined blending ratio is used.

(7) Construction of root-solidifying part After injecting the root-solidifying liquid, the auger drive device 25 is moved up and down, so that the excavated soil is repeatedly stirred up and down while rotating the auger screw 27 and mixed with the root-solidifying liquid. As a result, a solidified portion 35 made of soil cement is constructed.

(8) Pile circumference filling liquid injection The liquid supplied to the auger screw 27 is switched to the pile circumference filling liquid, and this pile circumference filling liquid is injected into the excavation hole from the excavation head 26. The pile circumference filling liquid is injected over a predetermined depth range from the root hardening portion 35 while the auger screw 27 is rotated upward. As this pile circumference filling liquid, cement milk having a predetermined blending ratio is used.

(9) Pile circumference fixing part construction After injecting the pile circumference filling liquid, the auger drive device 25 is moved up and down to repeatedly agitate the excavated earth and sand while rotating the auger screw 27 and mix with the pile circumference filling liquid. Thereby, the pile periphery fixing | fixed part 36 by soil cement is built.

3. Built-in piles (see Fig. 6)
(10) Inserting the lower pile Use the earth drill machine 1 again to build the ready-made pile. The ready-made pile used in this embodiment is a joint pile composed of a lower pile and an upper pile, and a node pile is used for the lower pile. The kelly bar 9 is pulled toward the boom 4 and the lower pile 37 is suspended by the auxiliary winding rope 32 and inserted into the excavation hole.

(11) Inserting the upper pile With the lower pile 37 supported by the casing 33 via the jig 41 composed of a pair of bars, the upper pile 38 is connected to the upper end of the lower pile 37 and the upper pile 38 is supplementally wound. It is suspended by the rope 32 and inserted into the excavation hole. A weldless joint is used for connecting the upper and lower piles.

(12) Rotational press-fitting Connect the kelly bar 9 to the upper end of the upper pile 38 via a yatco 39, and rotate and press-fit the joint piles 37, 38 to a predetermined depth by the rotation and pushing force of the kelly bar 9.
(13) Pile top end set Level 40 is used to set the pile top end.
(14) Pulling out the casing The Yatco 39 is separated and removed from the upper pile 38, the kelly bar 9 is pulled toward the boom 4, and the casing 33 is pulled out by the auxiliary winding rope 32. The construction is completed as described above.

According to the above embodiment of the present invention, the following effects can be expected.
Each process of the embedded pile method can be shared by an earth drill machine and a pile driver. For example, when the main excavation for the n-th pile and the construction process of the root-clamping part / pile circumference fixing part are carried out by the pile driving machine, the earth drill machine is used for the (n-1) -th pile. It is possible to effectively use these construction machines without letting the construction / rotation press-fitting process or the preceding excavation process for the (n + 1) -th pile be performed. Thereby, the improvement of construction efficiency can be aimed at. In order to improve the construction efficiency by such a technique, the number of earth drill machines is not limited to one, and two or more earth drill machines may be used.

  By performing prior excavation and discharging in the same manner as the earth drill method, it is possible to prevent overflow of the soil cement rising from the excavation hole, and to suppress the generation of industrial waste.

  By installing the casing, it is possible not only to secure a scaffold for construction using this, but also to maintain excavation accuracy, and to ensure quality and safety even when connecting the upper and lower piles can do.

It is an example of the earth drill machine used for this invention construction method, Comprising: It is a side view which shows a drilling attitude | position. It is a side view which shows the auxiliary winding crane attitude | position of the ground drill machine. It is a side view which shows an example of the three-point pile driver used for this invention construction method. It is a figure which shows the construction procedure of this invention construction method. It is a figure which shows the construction procedure following FIG. It is a figure which shows the construction procedure following FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground drill machine 2 Crawler traveling body 3 Revolving body 4 Boom 5 Front arm 7 Hoisting rope 9 Kelly bar 11 Keriba driving device 13 Rotation driving device 14 Pushing device 20 Three-point support pile driver 21 Crawler traveling body 22 Revolving body 23 Leader 25 Auger drive device 26 Excavation head 27 Auger screw 31 Excavation bucket 32 Supplementary winding rope 33 Casing 35 Root consolidation part 36 Pile circumference fixing part 37 Lower pile 38 Upper pile

Claims (2)

A swivel body, a boom and a front arm equipped on the swivel body, a hoisting rope and an auxiliary hoisting rope hanging from the tip of the boom, a kelly bar supported by the hoisting rope, and a kerry bar provided on the front arm. An earth drilling machine equipped with a Keriba drive device that gives rotational force and pushing force to
Pile driver comprising a revolving body, a leader equipped on the revolving body, an auger drive device provided on the leader so as to be movable up and down, and an auger screw attached to the auger drive device and having an excavation head at the tip An embedded pile construction method using an earth drill machine and a pile driving machine, characterized by using the machine and performing the following steps.
a. Connecting a bucket to the kelly bar of the earth drill machine, and excavating and excavating the ground surface layer part to a predetermined depth b. A main drilling from the bottom of the preceding drilling hole to a predetermined depth by an auger screw of the pile driver c. Supplying root-setting liquid into the auger screw and injecting the root-setting liquid from the excavation head over a predetermined depth range above the bottom of the excavation hole; d. Elevating and lowering the auger screw to repeatedly stir up and down excavated earth and sand and mix with the root hardening liquid to form a root hardening part e. Pulling up the auger screw to above the root consolidation part, supplying pile circumference filling liquid into the auger screw, and extending the pile circumference filling liquid from the excavation head over a predetermined depth range above the root consolidation part. Injecting step f. Elevating and lowering the auger screw to repeatedly agitate the excavated earth and sand and mix with the pile circumference filling liquid to form a pile circumference fixing part g. Hung a ready-made pile by the auxiliary hoisting rope of the earth drill machine, and inserting the ready-made pile into the main excavation hole h. A step of connecting the upper end of the ready-made pile to the kelly bar and rotationally press-fitting the ready-made pile to a predetermined depth i. The embedded pile construction method using both the earth drill machine and the pile driving machine according to claim 1, comprising a step of suspending the casing by the auxiliary hoisting rope and building the casing in the preceding excavation hole.

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