JP2014201926A - Oblique earth-retaining wall formation device and construction method of underground structure using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a practical oblique earth-retaining wall formation device for executing an oblique earth-retaining method.SOLUTION: This device comprises a chain conveyor cutter 7, a pile driving machine 2 for standing the chain conveyor cutter 7 by inclining at a predetermined angle θ to the vertical direction and a connection unit 20 for liftably connecting the chain conveyor cutter 7 to the pile driving machine 2. The connection unit 20 comprises a cutter holder 25 slidably peripherally contacting with a cutter guide bar 10 and having a first receiving surface 25a for enclosing the cutter guide bar 10 by exceeding the load direction by an inclination of the predetermined angle and a leader holder 24 slidably peripherally contacting with a leader guide bar 3a and having a second receiving surface 24a for enclosing the leader guide bar 3a by exceeding the load direction.

Description

  The present invention relates to an oblique earth retaining wall forming apparatus including a chain conveyor cutter for excavating underground and a method for constructing an underground structure using the apparatus.

  When constructing underground structures such as foundation footings, underground beams, underground pipes (including waterways), box culverts, etc. using the open-cut method, the method of excavating after earth retaining work and then building the underground structure is common. Is.

  In the case of earth retaining, if a certain excavation depth is exceeded, supporting work such as a cut beam, an uprising, a ground anchor, etc. that support the earth retaining wall is required.

  When using a support work, secondary work other than the original work, such as assembling the support work and casting the concrete away from the support work, and the time required for the work are required, and extension of the work period and cost increase can be avoided. Absent.

  For this reason, Patent Document 2 describes an oblique earth retaining method in which a steel sheet pile is tilted obliquely (for example, about 10 degrees with respect to the vertical).

  In the oblique earth retaining method, since no supporting work is used, excavation and the like are easy, but there is also a problem that deformation of the earth retaining wall tends to be large.

  For this problem, the rigidity of the earth retaining wall may be improved as compared with the case of using a steel sheet pile. Furthermore, it is desirable not to reinforce the steel sheet pile with another member but to increase the rigidity of the retaining wall itself.

  To do so, rotate one or more augers to excavate the ground, discharge cement milk to mix and agitate the excavated soil, and make the cylindrical soil cement pillar diagonally continuous, It is conceivable to form an oblique earth retaining wall made of soil cement.

  However, in the auger, the rotating blades attached to the tip of the rotating shaft are only supported in a cantilever manner.

  Therefore, if it is supported and rotated obliquely, it is expected that the rotating shaft that supports the auger, which is the tip, bends downward due to gravity and cannot maintain the specified angle as the excavation depth increases. For this reason, it is not practical with an auger type excavator.

  On the other hand, Patent Document 1 (Japanese Patent No. 45004095) describes a chain conveyor cutter that excels in carrying out performance such as earth and sand as an excavator that changes to an auger type. In particular, refer to FIG. 1, FIG. 2, and FIG.

The present application further improves the technique described in Patent Document 1 and intends to provide an oblique soil cement earth retaining wall by an oblique earth retaining method capable of maintaining a predetermined angle.
Japanese Patent No. 45004095 JP 2010-229626 A

  It is an object of the present invention to provide a practical oblique earth retaining wall forming apparatus and related technology for implementing the oblique earth retaining method.

  An oblique earth retaining wall forming apparatus according to a first aspect of the present invention is a chain conveyor cutter, a pile driving machine for standing the chain conveyor cutter at a predetermined angle with respect to the vertical direction, and the chain conveyor cutter with respect to the pile driving machine. And a connecting unit that is connected to be movable up and down.

  The chain conveyor cutter includes a post body, a chain having a plurality of bits for excavating the underground, and a cutter guide bar fixed in parallel to the longitudinal direction of the post body.

  The pile driver is a pile driver main body traveling on the ground, a pile driver leader supported to be tiltable with respect to the pile driver main body, and for raising and lowering the pile driver leader up and down with respect to the pile driver main body. It has an arm and a leader guide bar fixed parallel to the longitudinal direction of the pile driver.

  The connecting unit slidably contacts the cutter guide rod and slidably contacts the leader guide rod with a cutter holder having a first receiving surface that surrounds the cutter guide rod beyond a load direction due to a predetermined angle of inclination. And a reader holder having a second receiving surface that surrounds the leader guide bar beyond the load direction due to the inclination at a predetermined angle.

  With this configuration, the pile driving machine leader and the chain conveyor cutter can be supported at a predetermined angle with respect to the vertical direction.

  Therefore, when the underground is excavated by the chain conveyor cutter, a prismatic cutting space having the predetermined angle is formed. When the cement milk is discharged from the chain conveyor cutter, stirred with the earth and hardened, the oblique retaining pillars are formed. It is formed.

  Furthermore, the target diagonal earth retaining wall (made of soil cement) is formed by arranging diagonal earth retaining pillars in the horizontal direction.

  Here, the pile driving machine leader and the chain conveyor cutter are positioned in parallel by the connecting unit, and the chain conveyor cutter is sandwiched by four cutting surfaces formed in the ground, so that the auger type The cutting surface does not bend so that it hangs downward.

  On the other hand, since the chain conveyor cutter is inclined at a predetermined angle from the vertical direction, the weight of the chain conveyor cutter has a component for returning the inclination to the vertical direction, and the component is a first receiving surface provided on the reader holder. To the cutter guide rod, and from the second receiving surface provided on the cutter holder to the cutter guide rod.

  However, in the above configuration, since these receiving surfaces are formed so as to surround the respective guide rods beyond the load direction due to the inclination, the load can be received on a wide surface and the surface pressure can be suppressed. Therefore, the holder does not bite into these guide rods to damage the guide rods, and the guide rods do not wear unevenly, and the oblique earth retaining wall can be formed smoothly.

  In the oblique earth retaining wall forming apparatus according to the second invention, in addition to the first invention, the connecting unit is disposed at least under the pile driving machine leader.

  With this configuration, the chain conveyor can be supported at a position immediately before the chain conveyor is free from the pile driving machine, and the angle of the chain conveyor can be appropriately maintained.

  In the oblique earth retaining wall forming apparatus according to the third invention, in addition to the first invention, at the lower part of the chain conveyor cutter at least at a lower side by an inclination of a predetermined angle, a plurality of bit moving regions are formed. A sliding plate that fills a gap that can be formed between the outer edge and the side portion of the post body and that contacts the cutting surface formed in the ground is provided on the side portion of the post body.

  With this configuration, the gap between the side surface and the cutting surface, which is the side where the own weight of the chain conveyor cutter acts, is filled with a sliding plate, and the sliding plate and the cutting surface are in close contact with each other, thereby utilizing the drag from the cutting surface. The angle of the chain conveyor cutter can be maintained more accurately.

  Therefore, using the above-mentioned diagonal retaining wall forming device to form a pair of oblique retaining walls that are inclined and face each other, to remove the soil in the region sandwiched by the pair of oblique retaining walls, to form a space, Underground structures can be built in the space.

  ADVANTAGE OF THE INVENTION According to this invention, the diagonal slanting column which maintains a predetermined angle can be paralleled in the horizontal direction, and the target slanting retaining wall can be formed. Since the chain conveyor cutter is sandwiched by the cutting surface in the ground and supported by the connecting unit, the cutting surface is not bent so as to hang downward like the auger type.

  Moreover, the slant retaining wall can be smoothly formed without receiving damage from the guide bar by receiving the load on the wide receiving surface of the connecting unit.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 is a side view of an oblique earth retaining wall forming apparatus according to an embodiment of the present invention, FIGS. 2 and 3 are an enlarged side view and an enlarged plan view of the vicinity of the connecting unit, respectively, and FIG. FIG. 4B is an enlarged side view of the vicinity of the return portion, and is a view taken along line A in FIG.

  As shown in FIG. 1, the oblique earth retaining wall forming apparatus according to the present embodiment is moved up and down with respect to the pile driving machine 2 through a pile driving machine 2 traveling on the ground 1 and a connecting unit 20 to the pile driving machine 2. A chain conveyor cutter 7 that is freely supported is provided.

  In this example, the cutting depth is about 21 m, the inclination angle θ with respect to the vertical direction is about −5 to 10 degrees, and the cutting width is about 1 m.

  Here, as shown in FIG. 1, the angle θ is positive when the vertical direction is 0 degree and the upper ends of the pile driving machine leader 3 and the chain conveyor cutter 7 are inclined rearward from the vertical direction. . That is, the angle θ of −5 degrees indicates a case where the upper ends of the pile driving machine leader 3 and the chain conveyor cutter 7 are inclined 5 degrees forward from the vertical direction.

  In order to satisfy the above specifications, the total length of the chain conveyor cutter 7 is about 30 m, and the maximum effective cutting length is about 23 m. Of course, these numerical values are merely examples, and various changes may be made.

  The pile driving machine 2 is arbitrary as long as it can appropriately support the chain conveyor cutter 7, and a commercially available product may be used.

  The pile driver 2 includes a self-propelled pile driver main body 2a, a long pile driver leader 3 whose lower end is swingably supported in front of the pile driver main body 2a, and a hydraulic pressure inside. It has a hoisting arm 2b for housing a cylinder (not shown) and hoisting the upper portion of the pile driving machine leader 3.

  A leader guide rod 3 a parallel to the longitudinal direction of the pile driver leader 3 is fixed to the front surface of the pile driver leader 3. Further, a locking portion 4 that overhangs forward is provided at the upper end of the pile driving machine leader 3, and a pulley 4a is rotatably supported on the locking portion 4.

  A wire 5 is stretched over the pulley 4 a, and the opposite side of the wire 5 is connected to a cutter hook 6 at an upper end portion of the chain conveyor cutter 7. Therefore, when the wire 5 is expanded and contracted, the chain conveyor cutter 7 can be raised and lowered with respect to the pile driving machine leader 3.

  The upper end portion of the chain conveyor cutter 7 is a drive portion 19 that houses an electric motor, a drive sprocket, etc. (not shown) inside, and the lower end portion has a return roller 30, and this lower end portion is mainly ground. Work inside and do excavation work.

  As shown in FIG. 3 and FIG. 4A, a pair of chains 15 is bridged over the drive sprocket and return roller 30, and when the drive sprocket rotates, the chains 15 are arranged around the post body 8 along a fixed track. Go around.

  The lower end part of the chain conveyor cutter 7 is a return part 18 and is preferably configured as shown in FIGS.

  In particular, as shown in FIG. 4A, a slurry discharge port 16 is provided in the vicinity of the return portion 18, cement milk is supplied to the slurry discharge port 16, and the cement milk is surrounded by a cutting surface in the vicinity of the return portion 18. Discharged into the evacuated space and mixed with the cut soil.

  Moreover, as shown in FIG.4 (b), it is also preferable to arrange | position the inclinometer 17 in the return part 18 vicinity, and to detect whether the angle of the return part 18 in the ground belongs to the predetermined range.

Now, when the post body 8 or the like is cut along a horizontal plane, it becomes as shown in FIG. Here, it is preferable that the post body 8 is, for example, two types of general structural rolled steel having a longitudinal elastic modulus of about 2.1 * 10 ⁷ kgf / cm ² and a section modulus of about 4500 cm ³ . Of course, these numerical values are merely examples, and various changes may be made.

  A pair of partition walls 11 project outward from both side surfaces of the post body 8, and the pair of chains 15 move in a space sandwiched between the partition walls 11. Both ends of the scraper 14 are fixed between the pair of chains 15, and the scraper 14 pumps earth and sand as the chain 15 moves.

  Further, the bit plate 12 is fixed to the outside of the chain 15 via the scraper 14 at a predetermined pitch, and a plurality of bits 13 are fixed to each bit plate 12 so as to face outward. The leading edge of the partition wall 11 and the inner surface of the bit plate 12 are in slidable contact.

  These bits 13 are core elements for excavating the ground, and the shapes of the four cutting surfaces formed by the chain conveyor cutter 7 are determined by the locus of the tip of the bit 13.

  As described above, the chain conveyor cutter 7 and the pile driving machine leader 3 are connected to each other in parallel and slidable by the connecting unit 20. The connecting unit 20 will be described in detail with reference to FIG.

  The connecting unit 20 shown in FIG. 3 is supported near the lower end of the pile driving machine leader 3. In addition, it is desirable to provide similar connection units 20 'at the upper and lower portions of the drive unit 19 shown in FIG. 1, but the number and positions of the connection units 20 can be variously changed.

  Now, in FIG. 3, horizontal support plates 3b project from the side surface of the pile driving machine leader 3 toward the chain conveyor cutter 7, and both corners of the support plate 3b are perpendicular to the plane of FIG. The side surfaces of the pair of leader guide rods 3a are fixed to each other in a cylindrical shape.

  On the other hand, on the chain conveyor cutter 7 side, a pair of left and right arm plates 9 are extended from the post body 8 toward the pile driving machine leader 3 side, and are fixed to the side surfaces of the pair of cutter guide bars 10 at their tip portions. The

  Then, the next connecting unit 20 is mounted on the leader guide bars 3a and 3a and the cutter guide bars 10 and 10 so as to be slidable in the direction perpendicular to the plane of FIG.

  The connection unit 20 has the following elements. The center is a unit body 21 having a substantially rectangular or circular shape, and the bottom of the unit hook 22 having a through hole 22a on the center line is fixed so that the unit hook 22 stands.

  As shown in FIG. 2, a unit wire 23 is connected to the through hole 22 a of the unit hook 22. Note that the unit wire 23 is separate and independent from the wire 5. The position in the height direction where the connecting unit 20 is arranged is determined by extending or contracting the unit wire 23.

  As shown in FIG. 3, a leader holder 24 is provided on the pile driving machine leader 3 side of the unit main body 21, and a cutter holder 25 is provided on the chain conveyor cutter 7 side.

  The cutter holder 25 is formed with a first receiving surface 25a that is in contact with the circumferential surface of the cutter guide bar 10 about three-quarters. The reader holder 24 has a circumference of about three-fourths of the circumferential surface of the leader guide rod 3a. A second receiving surface 24a is formed in contact therewith.

  In particular, as indicated by the hatched portions in FIG. 3, these surfaces 25a and 24a surround the cutter guide bar 10 and the leader guide bar 3a, respectively, beyond the load direction (arrow W) due to a predetermined angle of inclination. Please pay attention to.

  As shown in FIG. 1, when the predetermined angle θ is positive and the upper ends of the pile driving machine leader 3 and the chain conveyor cutter 7 are inclined backward, the angle of gravity acting on the chain conveyor cutter 7. The θ tangential component acts from the chain conveyor cutter 7 to the pile driver leader 3 side as indicated by an arrow W.

  Here, in FIG. 3, if the hatched portion is not provided and omitted, the contact area between the cutter guide rod 10 and the first receiving surface 25a or between the leader guide rod 3a and the second receiving surface 24a is reduced, and the contact is made. The portion strongly bites into these guide rods 10, 3a, and it becomes easy to cause scratches or uneven wear.

  Once such damage occurs, the parallelism between the pile driver leader 3 and the chain conveyor cutter 7 decreases, and large-scale repairs such as parts replacement are essential. However, in this embodiment, since the contact area is increased and the surface pressure is reduced as described above, such inconvenience can be sufficiently suppressed.

  Furthermore, as shown in FIGS. 4A and 4B, it is desirable to apply the following allowance in the return portion 16 that is most flexible.

  A sliding plate 33 is added to the return unit 18 as follows. That is, in the side portion that is on the lower side due to the inclination of the predetermined angle θ (in this example, the angle θ is positive, the right side in FIG. 4A), the disc-shaped shaft portion slides at the center portion of the return roller 30. A plate 31 is attached, and a U-shaped peripheral sliding plate 32 is attached to the peripheral portion.

  In this way, the gap that can be formed between the outer edge of the moving region of the bit 13 and the side portion of the post body 8 is filled with the sliding plate 33, and the sliding plate 33 contacts the cutting surface formed in the ground. Will face.

  By doing so, the sliding plate 33 and the cutting surface are brought into close contact with each other, and a drag force from the cut surface acts on the sliding plate 33, so that the angle θ of the chain conveyor cutter 7 can be held more accurately.

  Of course, a similar sliding plate may be provided on the opposite side of the shaded portion in FIG. Further, in this example, the sliding plate 33 is divided into the shaft sliding plate 31 and the peripheral sliding plate 32. However, if there is no particular problem, these may be integrated.

If you use the above diagonal retaining wall forming device,
(Step 1) A step of forming a pair of diagonal earth retaining walls that are inclined backward and face each other.
(Step 2) A step of forming a space by removing soil in a region sandwiched between a pair of diagonal retaining walls,
(Step 3) It will be easily understood that a method comprising the step of building an underground structure in the formed space can be carried out.

  The underground structure is optional. For example, well-known things such as foundation footings, underground beams, underground pipes, and box culverts can be freely combined.

  Further, the process may be left as it is (Step 3), or the soil may be backfilled again to be the same level as the outer side of the oblique earth retaining wall. Furthermore, before refilling the soil, the oblique earth retaining wall may be removed or left as it is.

The side view of the diagonal earth retaining wall forming apparatus in one embodiment of this invention The expanded side view near the connection unit in one embodiment of the present invention The enlarged plan view near the connection unit in the embodiment of the present invention (A) Enlarged side view of the vicinity of the return portion in one embodiment of the present invention (b) View along arrow A in FIG. 4 (a)

DESCRIPTION OF SYMBOLS 1 Ground 2 Pile driver 2a Pile driver main body 2b Hoisting arm 3 Pile driver leader 3a Leader guide rod 4 Locking part 5 Wire 6 Cutter hook 7 Chain conveyor cutter 8 Post body 9 Arm plate 10 Cutter guide rod 11 Bulkhead 12 Bit plate 13 Bit 14 Scraper 15 Chain 16 Slurry discharge port 17 Inclinometer 18 Return portion 19 Drive portion 20 Connecting portion 21 Unit body 22 Unit hook 23 Unit wire 24a Second receiving surface 25 Cutter holder 25a First receiving surface 30 Return roller 31 Shaft sliding plate 32 Perimeter sliding plate W Load direction

Claims (4)

Chain conveyor cutter,
A pile driver for inclining the chain conveyor cutter at a predetermined angle with respect to the vertical direction;
An oblique earth retaining wall forming device comprising a connecting unit that connects the chain conveyor cutter to the pile driving machine so as to be movable up and down,
The chain conveyor cutter is
The post body,
A chain having a plurality of bits excavating in the ground and circling the post body;
A cutter guide bar fixed parallel to the longitudinal direction of the post body,
The pile driver is
A pile driver body traveling on the ground,
A pile driver reader supported to be tiltable with respect to the pile driver body;
A hoisting arm for hoisting the pile driver leader with respect to the pile driver body;
A leader guide bar fixed parallel to the longitudinal direction of the pile driver,
The connecting unit is
A cutter holder having a first receiving surface that slidably surrounds the cutter guide rod and surrounds the cutter guide rod beyond a load direction due to the inclination of the predetermined angle;
A slanted earth retaining member comprising a leader holder having a second receiving surface surrounding the leader guide rod in a slidable manner around the leader guide rod and exceeding the load direction due to the inclination of the predetermined angle Wall forming device. The oblique earth retaining wall forming device according to claim 1, wherein the connection unit is disposed at least in a lower portion of the pile driving machine leader. In the lower part of the chain conveyor cutter, at least the side part which is the lower side by the inclination of the predetermined angle is filled with a gap that can be formed between the outer edge of the moving area of the plurality of bits and the side part of the post body. The sloping retaining wall forming apparatus according to claim 1, wherein a sliding plate that is in contact with a cutting surface formed in the ground is provided on a side portion of the post body. A pair of diagonal earth retaining walls that are inclined and faced using the oblique earth retaining wall forming device according to claim 1,
Removing the soil in the region sandwiched by the pair of diagonal retaining walls to form a space;
An underground structure construction method for constructing an underground structure in the space.