JP2997402B2 - Sheet pile press-in method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for press-fitting a sheet pile into a hard or super-hard ground where rock, rock, concrete or the like is present, and in particular, excavating such a hard or super-hard ground and press-fitting a sheet pile. And a construction method that is performed simultaneously.

[0002]

2. Description of the Related Art When the ground is relatively soft general soil, a sheet pile is supported along a rotation driven excavation spindle such as an earth auger, and a ground excavation bit at the tip of the excavation spindle is used. While excavating, sheet piles can be pressed in at the same time. However, in this case, in order to raise the excavation spindle while leaving the sheet pile in the excavation hole, in a conventional general excavator such as an earth auger, it is necessary to make the diameter of the excavation bit at the tip of the excavation spindle smaller than the width of the sheet pile. . That is, if the diameter of the excavation bit is larger than the sheet pile width, the excavation bit is caught on the tip of the sheet pile when the excavation spindle is pulled up, so that the excavation spindle cannot be pulled up. Therefore, the diameter of the excavation hole formed by the excavation bit is necessarily smaller than the width of the sheet pile to be press-fitted therein, and it is extremely difficult to press-fit the sheet pile.

On the other hand, when a sheet pile is pressed into a hard or super-hard ground in which rock, rock, concrete or the like is present, the ground cannot be excavated by an earth auger or the like. Or, by a drilling device equipped with a down-the-hole hammer, first excavate the ground to form a digging hole, and put a sheet pile support material such as sand, earth and sand into the digging hole, and then use an earth auger etc. A sheet pile is driven into the borehole. However, in such a so-called pre-boring method, the excavation of the ground and the press-fitting of the sheet pile are separate work, and the work of putting the sheet pile support material into the borehole is also necessary. In the case where the sheet pile exists, it is necessary to perform the correction work many times during the press-fitting, such that the pressed sheet pile shifts from a predetermined driving position due to a boulder or the like, or is inclined. The construction requires a lot of trouble and a long time, and the construction efficiency is remarkably reduced.

[0004] In view of the above problems, the present invention provides a method for quickly and easily press-fitting a sheet pile into a hard or ultra-hard ground in which rock, rock, concrete, or the like is present, at a predetermined position. The purpose is to provide.

[0005]

According to a first aspect of the present invention, a casing 6 is externally fitted to a rotary driven excavating spindle 5.
At the same time, a sheet pile 10 is arranged along the casing 6, and
Eccentric excavation on the excavation spindle 5 via the down-the-hole hammer 8
The cutting bit 9 is attached and the eccentric drill bit 9 bit
The main body 9a is used when the drill bit 9 is pulled out from the ground.
Excavation spindle to prevent collision with sheet pile 10 along casing 6
5 eccentrically with respect to the rotation center axis O of the down Zahoruhan
The hammer 8 is formed integrally with the hammer 8
Due to the rotational impact of the eccentric drill bit 9
The board is excavated, and the casing 6 and the sheet pile are excavated following the excavation.
10 after press-fitting of the sheet pile 10 is completed.
The eccentric drill bit is positioned so that the main body 9a does not collide with the sheet pile 10.
The casing 6 and the eccentric excavation in this state.
The bit 9 is pulled out from the ground .

According to a second aspect of the present invention, a plurality of excavating spindles 18 and 19 are provided with external casings 20 and 21, respectively. The eccentric drill bits 22 and 23 that can be pulled out from the ground so as not to collide with the sheet pile are attached via down-the-hole hammers 24 and 25,
By using a multi-axis excavator in which the maximum width H of the composite trajectory circle So formed so as to partially overlap by the rotation of each of the eccentric drill bits 22 and 23 is substantially the same as the sheet pile width W,
In the first sheet pile 10A, one joint engaging portion 10a is located within the compound locus circle So and the other joint engaging portion 1
0b is supported by the plurality of casings 20 and 21 so as to be located outside the compound locus circle So, and the eccentric drill bits 22 and 2 hit by the down-the-hole hammers 24 and 25.
The first sheet pile 1 while excavating the ground by the rotary impact action of 3
0A, and then the excavator is advanced approximately by sheet pile 10 minutes to support the second sheet pile 10B in the opposite direction to the first sheet pile 10A on the plurality of casings 20, 21 and the second sheet pile 10B.
B, one of the joint engaging portions 10b is positioned outside the compound locus circle So to engage with the joint engaging portion 10a of the first sheet pile 10A located in the excavated hole and the second sheet pile 10B. With the other joint engaging portion 10a positioned in the composite locus circle So, the second sheet pile 10B is press-fitted while excavating the ground with the eccentric excavation bits 22 and 23, and thereafter the above steps are repeated. It is characterized by.

[0007]

In the sheet pile driving method according to the first aspect, the ground is excavated by the rotary impact action of the excavation bit 9 struck by the down-the-hole hammer 8, and the sheet pile 10 is press-fitted following this excavation. Excavation of a hard or super-hard ground in which rock, rock, concrete, or the like exists can be easily performed, and press-fitting of a sheet pile into such ground can be performed quickly, easily, and accurately at a predetermined position. Moreover, since the drill bit is an eccentric drill bit 9 that is eccentric so that the bit body 9a can be pulled out without colliding with the sheet pile 10 after the press-fitting of the sheet pile 10, the eccentric drill bit 9 is used. The boreholes (for example, indicated by 17A and 17B in FIG. 5) can have a sufficiently large inside diameter and can be formed to be equal to or larger than the sheet pile width W, so that the sheet pile 10 can be accurately positioned at a predetermined position while maintaining straightness. Can be press-fit.

[0008] In the sheet pile driving method according to the second aspect, the multi-axis excavator is disposed at a predetermined location on the ground, and the first sheet pile 10A is connected to one of the joint engaging portions 10a by the composite locus circle So. Are supported by both casings 20 and 21 so that the other joint engaging portion 10b is located outside the trajectory circle Sb of the composite trajectory circle So. The first sheet pile 10A is press-fitted to a predetermined depth in the ground while excavating the ground by the rotary impact action of the eccentric excavation bits 22 and 23 to be hit. After the press-in of the first sheet pile 10A is completed, the eccentric drill bits 22 and 2
3 is rotated to a position where it does not collide with the tip of the first sheet pile 10A.
Can be pulled out of the ground along.

Next, the multi-axis excavator is advanced substantially by the width of the sheet pile W to support the second sheet pile 10B in the opposite direction to the first sheet pile 10A by the casings 20, 21 and the second sheet pile 1
0B of the joint locus circle So
Of the first sheet pile 10A located in the already excavated hole, and the other joint engaging part 10a of the second sheet pile 10B. With the composite locus circle So positioned within the locus circle Sa, the second sheet pile 10B is press-fitted while excavating the ground with the eccentric excavation bits 22 and 23, and the second sheet pile 10B is joined to the first sheet pile 10A. . Thereafter, 10 rows of sheet piles can be formed by repeating the above steps.

According to the driving method of the second aspect, the maximum width H of the composite trajectory circle So formed so as to partially overlap with each rotation of the two eccentric drill bits 22 and 23 is substantially the same as the sheet pile width W. Two eccentric drill bits 22,
Since the sheet pile 10 is press-fitted using the 23, the drilling hole can be effectively excavated without forming an unexcavated portion between adjacent drilling holes, and the first sheet pile 10 already press-fitted can be drilled.
When the second sheet pile 10B is press-fitted into A, one of the eccentric digging bits 23 for digging the digging hole into which the second sheet pile 10B is press-fitted is engaged with the joint engaging portion of the first sheet pile 10A adjacent thereto. There is no collision with 10a. And especially according to the construction method of this claim 2, a large sheet pile 1 having a wide sheet pile width W.
Ideal for zero press fit. That is, in the case of a large sheet pile 10,
When a single-axis drilling rig is used, the inner diameter of the drilling hole drilled by one eccentric drilling bit tends to be larger and the ground tends to be unnecessarily drilled. Since the excavation hole is formed by the horizontally long compound trajectory circle So connected in the lateral direction by the eccentric drill bit, the ground having the minimum size necessary for press-fitting the sheet pile 10 can be excavated, and a plurality of eccentric drill bits can be formed. There is an advantage that it is possible to cope with sheet piles 10 of various shapes and sizes by the combination of.

[0011]

Embodiments will be described with reference to the drawings.
FIG. 1 shows an excavator 1 used to carry out the method of the present invention, and FIG. 2 shows an enlarged view thereof. As is apparent from these figures, the excavator 1 has an auger machine 4 supported so as to be able to move up and down along a leader 3 erected by a crawler crane 2. A hollow excavating spindle 5 rotationally driven by the auger machine 4 is hung and connected, and a casing 6 which is externally fitted to the excavating main spindle 5 is hung and connected. Is rotationally driven by a casing rotation driving means 7 provided in the first position. An eccentric drill bit 9 is integrally provided at the lower end of the drill spindle 5 via a down-the-hole hammer 8, and the eccentric drill bit 9 rotates with the rotation of the drill spindle 5 by the auger machine 4. At the same time as rotating around O, it is hit by a down-the-hole hammer 8 driven by compressed air supplied to the hollow portion 5a of the excavating main shaft 5. At an upper end portion of the casing 6, a chuck device 11 for supporting the sheet pile 10 is provided.
It is suspended by the sheet pile suspension means 12 shown in FIG.

FIGS. 3 and 4 show an eccentric drill bit 9 integrally mounted at the lower end of the drill spindle 5 via a down-the-hole hammer 8, and the eccentric drill bit 9 is formed by a bit body 9a and a bit shaft 9a. When the drill bit 9 is pulled out of the ground after the press-fitting of the sheet pile 10 is completed, the excavation main shaft 5 is arranged so that the bit body 9a does not collide with the sheet pile 10.
Is formed eccentrically with respect to the rotation center axis O. As shown in FIG. 3, the eccentric drill bit 9 is formed substantially in a boot shape in a side view, and the bit body 9a is formed in a substantially sector shape in a plan view or a bottom view (see FIG. 4). Also, a number of projections 13 are provided on the outer peripheral surface and the bottom surface of the bit main body 9a. In FIG. 4, reference numeral 14 denotes an air ejection hole which is opened on the bottom surface of the bit body 9a, and compressed air from the down-the-hole hammer 8 is ejected from the air ejection hole 14 so that excavated powder and the like are excavated when excavating rock or the like. It can be blown up to the ground through a gap between the drilling hole and the casing 6.

As shown in FIG. 4, the eccentric drill bit 9
The diameter of the maximum trajectory circle S of the eccentric digging bit 9 rotating about the rotation center axis O of the digging spindle 5 is formed to be substantially the same as the sheet pile width W. The sheet pile 10 has a center P of the sheet pile 10 with respect to a rotation center axis O of the drilling spindle 5 (which is also a rotation center axis of the eccentric drill bit 9 and a center axis of the casing 6) for each joint of the sheet pile 10. The engaging portions 10a,
It is supported by the casing 6 in a state shifted by a length E substantially corresponding to the width w of 10b. When mounting the sheet pile 10, the upper end of the sheet pile 10 is attached to the chuck device 1.
The lower end of the sheet pile 10 is supported by the casing 6 by inserting a fitting 15 provided on the casing 6 side into a receiving fitting 16 provided on the sheet pile 10 side (see FIG. 4).

Next, a method of press-fitting the sheet pile 10 by using the excavator 1 having the eccentric excavating bit 9 as described above will be specifically described with reference to FIGS.

First, the excavator 1 is arranged at a predetermined location on the ground, and as shown on the right side of FIG. It is supported by the casing 6 so that it is located within the maximum locus circle S and the other joint engaging portion 10b is located outside the maximum locus circle S. Then, the excavating spindle 5 is rotationally driven by the auger machine 4, and the eccentric excavating bit 9 is rotated by the rotation of the excavating spindle 5.
Is hit by a down-the-hole hammer 8, and the first sheet pile 10A is pressed into the ground to a predetermined depth while excavating the ground by the rotary hitting action of the eccentric drill bit 9. After the press-fitting of the first sheet pile 10A is completed, the rotation of the excavating spindle 5 is stopped at a position where the eccentric drill bit 9 does not collide with the tip of the first sheet pile 10A as shown by the phantom line on the right side of FIG. Then, the excavator 1 is pulled up to the ground, and the eccentric drill bit 9 is pulled out from the ground along the sheet pile 10. When the first sheet pile 10A is press-fitted, the joint engaging part 10b of the first sheet pile 10A is outside the maximum locus circle S and the part is not excavated. The ground portion to be excavated may be excavated by the excavator 1 in advance.

Next, after the excavator 1 lifted to the ground is advanced by the sheet pile width W, the second sheet pile 10B is moved to the first sheet pile 1.
0A, the first joint engaging portion 10b of the second sheet pile 10B is located outside the maximum locus circle S, and the first joint engaging portion 10b of the second sheet pile 10B is located in the excavated hole 17A.
The sheet pile 10A is engaged with the joint engagement portion 10a of the
With the other joint engaging portion 10a of the sheet pile 10B positioned within the maximum locus circle S, the ground is excavated by the rotary impact action of the eccentric excavation bit 9 as in the case of the first sheet pile 10A. The second sheet pile is press-fitted and joined to the first sheet pile 10A. After the press-fitting of the second sheet pile 10B is completed, the rotation of the excavating spindle 5 is stopped at a position where the eccentric drill bit 9 does not collide with the tip of the second sheet pile 10B as shown by the phantom line in the center of FIG. 1 is pulled up to the ground, and the eccentric drill bit 9 is pulled out from the ground along the second sheet pile 10B.

Subsequently, after the excavator 1 is further advanced by the sheet pile width W, the third sheet pile 10C is supported by the casing 6 in a direction opposite to the second sheet pile 10B, and the third sheet pile 10C is engaged with one of the joints. The portion 10b is positioned outside the maximum locus circle S and is engaged with the joint engaging portion 10a of the second sheet pile 10B located in the excavated hole 17B, and the other joint engagement of the third sheet pile 10C. In a state where the portion 10a is positioned within the maximum locus circle S, the third sheet pile 10C is press-fitted while excavating the ground by the rotary impact action of the eccentric excavation bit 9 as described above,
It is joined to the first sheet pile 10A. After the completion of the press-fitting of the third sheet pile 10C, the eccentric drill bit 9 is rotated by the eccentric drill bit 9 as shown in FIG.
As shown by the solid line on the left side of the figure, the vehicle is stopped at a position where it does not collide with the tip of the third sheet pile 10C, and the eccentric drill bit 9 is pulled out from the ground along with the third sheet pile 10C together with the excavator 1. Thereafter, the required number of sheet piles 10 such as the fourth sheet pile, the fifth sheet pile, and the like are press-fitted in the same manner as described above.

According to the press-fitting method of the above-described embodiment, the pile is excavated while the ground is excavated to form an excavation hole by the rotary impact action of the excavation bit 9 which is rotated by the excavation main shaft 5 and impacted by the down-the-hole hammer 8. Since it is possible to excavate hard or super-hard ground such as rock, boulder, concrete, etc., it is possible to press the sheet pile into the ground quickly, easily, and in a predetermined manner. Position can be done exactly. In this case, an eccentric drill bit 9 is used as the drill bit 9 so that the drill bit does not collide with the sheet pile 10 when the drill bit is pulled out of the ground. ) Can be formed to be sufficiently large and equal to or larger than the sheet pile width W, so that the sheet pile 10 can be easily press-fitted and accurately driven into a predetermined position while maintaining straightness.

In particular, according to the press-fitting method of this embodiment, the first sheet pile 10A and the second sheet pile 10B are formed by using the eccentric excavation bit 9 in which the diameter of the maximum trajectory circle S due to the rotation of the bit is substantially the same as the sheet pile width W. , The third sheet pile 10C and the like are press-fitted in the manner described above, so that adjacent drill holes (for example, 17A, 17
B) It is possible to effectively excavate the excavation hole without forming an unexcavated portion during the excavation, and for example, the first sheet pile 1 already press-fitted.
When press-fitting the second sheet pile 10B with respect to 0A,
The eccentric digging bit 9 for digging the digging hole 17B into which the sheet pile 10B is press-fitted does not hit the joint engaging portion 10a of the first sheet pile 10A adjacent thereto. Incidentally, if the eccentric excavation bit 9 hits the joint engaging portion of the sheet pile 10 already press-fitted, the joint engaging portion is deformed or damaged, and the sheet pile 10 is removed from the ground. In the case of pulling out, it is very difficult to perform the pulling out operation.
0 cannot be reused. In this regard, according to the above-described method, deformation and damage of the joint engaging portion of the sheet pile 10 can be prevented, and the work of pulling out the sheet pile 10 can be performed without difficulty.
Zero can be used many times.

In the above embodiment, the sheet pile 10 is connected to the excavator 1
Although the excavation is performed only by press-fitting, the excavation is performed by the rotary impact action of the eccentric excavation bit 9 and, at the same time, the sheet pile 10 is forcibly forced using a press-fitting hydraulic cylinder or a wire-type or chain-drive type narrowing-down means. By press-fitting, the work of press-fitting the sheet pile 10 can be performed even more efficiently.

Since the eccentric excavating bit 9 performs excavation by rotating the excavating main shaft 5 and hitting by the down-the-hole hammer 8 as described above, for example, as shown in FIG. When the rock Go is present in the lower layer of the rock, the rock Go can be easily excavated. Also, the bit body 9 of the eccentric drill bit 9
Since a large number of projections 13 are provided on the outer peripheral surface and the bottom surface of a, it is particularly effective for excavating the rock Go.

FIGS. 6 and 7 show two excavating spindles 18 and 1.
9 (see FIG. 7), casings 20 and 21 are externally fitted to both excavating spindles 18 and 19, respectively.
Eccentric drilling bits 22 and 23 that can be pulled out of the ground so as not to collide with the sheet pile 10 after the completion of driving of the sheet pile 10 are down-hole hammer 24,
25, and both eccentric drill bits 22 and 2
3 using a multiaxial excavator in which the maximum width H of a composite trajectory circle So composed of two trajectory circles Sa and Sb formed so as to partially overlap each other is substantially the same as the sheet pile width W. 10 shows an embodiment of a method of performing press-fitting of No. 10. In this case, the two eccentric drill bits 22 and 23 are attached to the drill spindles 18 and 19 with a height difference from each other so as not to hit each other during rotation (see FIG. 6).

In this press-fitting method, first, a multi-axis excavator is arranged at a predetermined place on the ground, and the first sheet pile 10A is connected to one of the joints as shown in the left side of FIG. Part 10a is located within the trajectory circle Sa of the composite trajectory circle So, and the other joint engagement portion 10b is
o, so that both casings 2 are located outside the locus circle Sb.
It is supported at 0,21. Then, similarly to the previous embodiment, the excavating spindles 18 and 19 are rotationally driven by the auger machine,
While rotating the eccentric drill bits 22 and 23 in opposite directions, and excavating the ground while hitting the eccentric drill bits 22 and 23 with down-the-hole hammers 24 and 25, the first sheet pile 10A is pressed into the ground to a predetermined depth. .

Next, the multi-axis excavator is advanced to the right in FIG. 7 by the width of the sheet pile W, and the second sheet pile 10B is moved to the first sheet pile 10B.
A is supported in both casings 20 and 21 in the opposite direction to A, and one of the joint engaging portions 10b of the second sheet pile 10B is positioned outside the locus Sb of the composite locus circle So, and the already drilled hole is excavated. Is engaged with the joint engaging portion 10a of the first sheet pile 10A located inside the second sheet pile 10B and the other joint engaging portion 10a of the second sheet pile 10B is positioned within the locus circle Sa of the composite locus circle So. Then, the second sheet pile 10B is press-fitted while excavating the ground with the eccentric excavation bits 22 and 23. Later,
The above steps may be repeated.

Also in the press-fitting method of this embodiment, the maximum width H of the composite trajectory circle So composed of the two trajectory circles Sa and Sb formed so as to partially overlap with each rotation of the eccentric excavation bits 22 and 23 is set. In order to press-fit the sheet pile 10 by using two eccentric drill bits 22 and 23 having almost the same width as the sheet pile width W, the drill hole is effectively formed without forming a remaining part between adjacent drill holes. The second sheet pile 10B can be excavated and, for example, the first sheet pile 10A already press-fitted.
When the press-fitting is performed, one eccentric digging bit 23 for digging a digging hole into which the second sheet pile 10B is press-fitted is brought into contact with the joint engaging portion 10a of the first sheet pile 10A adjacent thereto. Nothing.

In this embodiment, two excavating spindles 18, 1
Although the multi-axis excavator equipped with the excavator 9 was used, a multi-axis excavator having three or more excavation spindles can be used, and an eccentric drill bit may be attached to each excavation spindle at the lower end side. . Thus, according to the press-fitting method using such a multi-axis excavator, it is most suitable for driving a large sheet pile 10 having a wide sheet pile width W. That is, in the case of a large sheet pile 10,
When a single-axis excavator is used, the inner diameter of a drill hole excavated by one eccentric drill bit tends to increase and the ground tends to be unnecessarily excavated. According to this, since the excavation hole is formed by the horizontally long compound trajectory circle So connected in the lateral direction by the plurality of eccentric excavation bits, there is an advantage that the ground having the minimum size necessary for press-fitting the sheet pile 10 can be excavated. In addition, there is an advantage that a combination of a plurality of eccentric drill bits can cope with sheet piles 10 having various shapes and sizes.

In the above embodiment, the down-the-hole hammer driven by air pressure has been described, but the down-the-hole hammer driven by hydraulic pressure can also be used in the method of press-fitting a sheet pile according to the present invention.

[0028]

According to the method for press-fitting a sheet pile according to the first aspect, press-fitting of a sheet pile into a hard or super-hard ground in which rock, rock, concrete or the like is present can be performed quickly, easily and accurately at a predetermined position. It can be carried out. In addition, since the drill bit can be pulled out after the sheet pile press-in is completed without the bit body colliding with the sheet pile, its diameter is sufficiently large, so that the inside diameter of the drill hole is formed to be equal to or larger than the sheet pile width. The press-fitting of the sheet pile can be performed more easily, and the straight sheet can be maintained at a predetermined position while maintaining the straightness.

According to the method of press-fitting a sheet pile according to claim 2,
After completion of press-fitting of each sheet pile, by rotating the eccentric drill bit to a position where it does not collide with the pressed sheet pile tip,
The eccentric drill bit can be easily pulled out of the ground along the sheet pile. As described above, since the eccentric drill bit is eccentric so that the drill bit does not collide with the sheet pile when the drill bit is pulled out of the ground, the inner diameter of the drill hole can be formed sufficiently large, thereby facilitating press-fitting of the sheet pile. It is possible to press-fit into a predetermined position accurately while maintaining straightness, but in particular according to the method of this claim 2,
The excavation hole can be effectively excavated without forming an unexcavated portion between adjacent excavation holes, and when the second sheet pile is press-fitted into, for example, the first sheet pile already press-fitted, the second sheet pile is press-fitted. Eccentric digging bit for digging a digging hole without hitting the joint engaging portion of the first sheet pile adjacent thereto,
Therefore, deformation and damage of the joint engaging portion of the sheet pile can be prevented,
The sheet pile can be easily pulled out and the sheet pile can be used any number of times.

In particular, the method of press-fitting a sheet pile according to the second aspect is effective in press-fitting a large sheet pile having a wide sheet pile width. That is, in the case of a large sheet pile, the use of a single-axis excavator tends to increase the inner diameter of the excavation hole excavated by one eccentric excavation bit and excavate the ground more than necessary. According to the method of the second method, according to the use of the multi-axis drilling device, the drilling hole is formed by a plurality of eccentric drilling bits formed in a horizontally long compound trajectory circle connected in the lateral direction. In addition to being able to excavate the ground with a minimum size, it is possible to cope with sheet piles of various shapes and sizes by combining a plurality of eccentric excavation bits.

[Brief description of the drawings]

FIG. 1 is a side view of an excavator used for carrying out the method of the present invention.

FIG. 2 is an enlarged side view of the above-described excavator.

FIG. 3 is an enlarged side view of an eccentric drill bit.

FIG. 4 is a bottom view of the eccentric drill bit shown in FIG. 3;

FIG. 5 is an enlarged cross-sectional view for explaining a sheet pile press-fitting step.

FIG. 6 is a side view showing an embodiment using a multi-axis excavator.

FIG. 7 is a cross-sectional view of the multi-axial excavator according to the first embodiment.

[Description of Signs] 1 Excavator 3 Leader 4 Auger machine 5 Drilling spindle 6 Casing 8 Down the hole hammer 9 Eccentric drill bit 9a Bit body 9b Bit shaft section 10 Sheet pile (general name) 10A Sheet pile 10B Sheet pile 10C Sheet pile 10a Joint joint joint 10b Joint engaging portion 13 Projection 17A Drilling hole 17B Drilling hole 18 Drilling spindle 19 Drilling spindle 20 Casing 21 Casing 22 Eccentric drilling bit 23 Eccentric drilling bit 24 Down-the-hole hammer 25 Down-the-hole hammer O Center axis of rotation of drilling spindle W Sheet width w Width of joint part for sheet pile joint S Maximum locus circle H Maximum width So Compound locus circle

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E02D ^7/ 00-13/10

Claims (2)

(57) [Claims] [Claim 1] A casing is mounted on a rotary driven excavating spindle.
Equipped with external fittings and a sheet pile along the casing
And the eccentric shaft is eccentric via a down-the-hole hammer
Drill bit is mounted, eccentric drill bit bit book
When the body is pulled out of the ground,
To the rotation center axis of the excavation spindle so as not to collide with the sheet pile along
Eccentrically and integrally formed with the tow hole hammer,
Eccentric drill bit hit by unza hole hammer
Excavates the ground by the rotating impact action of
Press the casing and the sheet pile in, and press-fit the sheet pile.
Eccentric drilling to a position where the bit body does not collide with the sheet pile after completion
Rotate the bit, and in this state casing and eccentric drilling
A method of press-fitting a sheet pile so that the bit is pulled out from the ground . 2. A plurality of excavating spindles driven by rotation are each provided with an outer casing, and an eccentric that can be pulled out from the ground at the tip of each excavating spindle so that the bit body does not collide with the sheet pile after completion of press-fitting of the sheet pile. Attaching the drill bit via the down-the-hole hammer, and using a multi-axis drilling machine in which the maximum width of the compound trajectory circle formed so as to partially overlap with each rotation of these eccentric drill bits is almost the same as the sheet pile width, The first sheet pile is supported by the plurality of casings such that one joint engaging portion is located within the compound locus circle and the other joint engaging portion is located outside the compound locus circle, The first sheet pile is press-fitted while excavating the ground by the rotary striking action of each eccentric drill bit hit by the down-the-hole hammer, and then the excavator is advanced substantially by the sheet pile width, and the second sheet pile is moved. Instruct the plurality of casings in the direction opposite to the first sheet pile, and position one joint engagement portion of the second sheet pile outside the compound locus circle, and connect the joint of the first sheet pile located in the excavated hole. The second sheet pile while excavating the ground by the rotary striking action of each excavation eccentric bit in a state where the second joint sheet is engaged with the second sheet pile and the other joint engagement section of the second sheet pile is positioned in the compound locus circle. Press-fitting, and thereafter repeating the above steps.