JP3978469B2 - Expansion drilling equipment and pile bottom expansion method - Google Patents

Description

  The present invention relates to an expansion excavation apparatus and a pile bottom expansion method that are provided inside a cylindrical drill such as a casing tube used in the all casing method and excavate the surrounding ground.

  Conventionally, the all casing method is used when the hardness of the ground is high or when there is a concern about the collapse of the hole wall on the soft ground.

  In the all-casing method, first, the earth and sand in the casing tube is excavated and removed with a hammer grab while swinging, rotating, and pushing over the entire length of the drilling hole using an all-round rotating machine and a casing tube, and a predetermined depth is obtained. After drilling up to this point, hole bottom processing is performed. And it is the construction method which constructs a foundation pile by building in a reinforcing bar, driving concrete with treme, and pulling out and collecting a casing tube and treme with concrete pouring.

  The foundation pile constructed by the all-casing method is a cylinder that is slightly smaller than the casing tube, and the all-round rotating machine is provided corresponding to each diameter of the casing tube to grip and rotate the outer periphery of the casing tube. ing.

  The foundation piles have different diameters depending on the size of the building to be constructed and the condition of the ground, but it is difficult to construct two types of foundation piles at one site, and the cost also increases. Here, there is a method of increasing the support strength by expanding the diameter of the lower end portion of the foundation pile. An apparatus for expanding a cylindrical hole bottom has also been developed.

  For example, along the axial center of a cylindrical caisson, it is thrown into the caisson, and has a drilling blade to expand radially outward at a required opening degree. Drilling buckets have been developed (see, for example, Patent Document 1).

  In addition, a bottom expansion method has been developed in which a lower part of the casing is expanded using a cylindrical excavating casing provided with expanding blades on the outer periphery (see, for example, Patent Document 2). When the casing is rotated in the forward direction, the enlarged wing can be closed to form a small diameter hole, and when rotated in the opposite direction, the enlarged wing can be opened to form a large diameter hole. can do.

Japanese Patent Laid-Open No. 10-184257 (paragraph number 0010, FIG. 1) JP 09-228769 A (paragraph numbers 0019 to 0020, FIG. 5)

  However, since the drilling bucket described in Patent Document 1 is arranged separately from the caisson, it is necessary to provide a separate rotation driving means, which increases the equipment.

  Further, in the bottom expansion method described in Patent Document 2, since the expanding blade is integrally provided on the outside of the casing, when a large pressure is applied to the outer periphery of the casing, such as when excavating a hard rock, Even when the expanding blade is closed to form a small-diameter hole, a large pressure is applied to the expanding blade and the blade is damaged.

  Therefore, the problem to be solved by the present invention is to provide a widening excavation apparatus and a pile bottom expansion method that can be quickly attached with a simple structure and can reliably expand the diameter without reducing the strength of the casing. There is to do.

  In order to solve the above-described problem, an expanded excavation apparatus according to a first configuration of the present invention is an expanded excavation apparatus provided at a lower portion of a cylindrical casing having a cutting edge formed at a lower end portion thereof. A base part that is detachably fixed to the lower inner side of the base part, and a bit is fixed to a tip part attached to the lower side of the base part, and the bit is linearly moved outward from the outer peripheral surface of the casing. And an arm part to project.

  By forming a hole with a circular cross section up to a predetermined depth by the casing, removing the internal earth and sand by means of soil removal such as a hammer grab, and then lifting the casing a little, a cylindrical shape that is the same as the cross sectional shape of the casing at the bottom of the casing A space is formed.

  An expanding excavator is inserted into the casing from above, and the base is fixed to the inside of the lower part. Here, fixing so as to be detachable is only required to hold the expansion excavator so as not to fall out of the casing, and includes a state where there is some play.

  When the base portion is fixed to the casing, the arm portion attached to the lower side of the base portion is disposed below the front end of the casing. The arm part moves linearly, protrudes radially outward of the casing, and rotates together with the casing to form an enlarged hole part concentric with the casing. Therefore, when fixing the base part to the casing Moreover, it is not necessary to match the center position of the casing.

  Since the expanded excavator is fixed to the inside of the casing after the hole having a predetermined depth is formed, no load is applied to the expanded excavator when the hole that is not expanded by the casing is formed.

  Moreover, since the expansion excavator rotates together with the casing, it is not necessary to prepare a dedicated drive source for causing the rotational movement. The bit preferably has a high hardness, and for example, tungsten can be used.

The expansion excavation apparatus according to the second configuration of the present invention is attached to the arm portion, the first arm portion attached to the base portion and movable linearly to the side, and the first arm portion. Then, the bit is fixed to the tip, and a second arm that can move linearly to the side and protrude outward from the outer peripheral surface of the casing is provided.
According to this structure, the stroke of an arm part can be lengthened, and even when the diameter of a casing is small, the diameter of the expansion hole part formed in the lower part can be enlarged. Moreover, if the stroke of the first arm part and the stroke of the second arm part are set to different lengths, the protruding length of the bit can be set to a plurality, and a plurality of types of widened holes having different outer diameters. The part can be formed.

In a third configuration of the present invention, guide rail portions for guiding the base portion to the lower side of the casing are formed in parallel to the center line of the casing at a plurality of locations on the inner peripheral surface of the casing. .
According to this structure, the base part of an expansion excavation apparatus can be suspended with a crane etc., and it can insert in an inside from the upper end of a casing along a guide rail. When lowering the expanded excavator, even if the wire suspended on the crane is displaced from the center of the casing, the expanded excavator is held by the guide rail so that the expanded excavator is not displaced in the horizontal direction. Can be lifted and lowered easily.

According to a fourth configuration of the present invention, a guide member that guides the earth and sand excavated by the bit to the center side of the casing is provided in the arm part, and an accumulation bucket that accumulates the earth and sand is provided at a position below the arm part. It is provided.
According to this configuration, the arm portion can be reliably advanced and retracted, and the excavated earth and sand can be collected in the accumulation bucket according to the excavation amount. The hydraulic cylinder can be manually operated to make the exploration excavator lightweight and simple. For example, the hydraulic cylinder can be operated quickly using a hydraulic pump unit driven by an engine or electric motor. Can be configured.

In a fifth configuration of the present invention, a spacer member is detachably provided on the side opposite to the protruding direction of the arm portion of the base portion.
According to this configuration, when a large-diameter casing is used, the spacer member can be attached to the base portion. In this case, since the spacer member is provided on the side opposite to the protruding direction of the arm portion, the protruding length of the arm portion does not change, and the size of the expanded hole portion is determined depending on the presence or absence of the spacer member and the diameter of the casing. Regardless, it can be set to a constant size.

  The pile bottom expansion method according to the sixth configuration of the present invention is a method of excavating the ground using a cylindrical casing having a cutting edge formed at the lower end, and constructing a foundation in the casing. A step of removing earth and sand in the casing after excavating the ground, a base portion fixed to the lower portion of the casing in the casing, and a bit fixed to the tip portion attached to the lower side of the base portion Inserting a spreading excavator comprising an arm part linearly movable laterally and an accumulation bucket disposed at a position below the arm part from the upper part of the casing and fixing the drilling apparatus to the lower end part; and Extending the arm, projecting the bit outward from the outer peripheral surface of the casing, rotating the expanding excavator together with the casing to excavate the ground, and expanding the lower part of the casing A step of accommodating the earth and sand excavated in the accumulation bucket, and after retracting the arm portion and taking out the expanded excavator from the upper part of the casing, in the hole formed by the casing and the expanded excavator And a process for constructing a foundation made of concrete.

  According to this configuration, the expanded excavator is inserted into the casing, the earth and sand excavated while forming the expanded hole portion is stored in the accumulation bucket, and after the expanded opening is formed, the expanded excavator is Can be taken out with excavated soil.

An expansion excavation apparatus according to a seventh configuration of the present invention is an expansion excavation apparatus provided at a lower portion of a cylindrical casing having a cutting edge formed at a lower end portion, and is attachable to and detachable from a lower portion inside the casing. A fixed base part, a fixed overhanging grip that is attached to the base part and driven to extend and contract toward the inner surface of the casing, and a bit that is attached to the lower side of the base part and fixed to the tip part And an opening / closing blade that expands the bit outward from the outer peripheral surface of the casing.
With this configuration, a fixed overhanging grip is overhanged to fix the expanding excavator to the casing inner surface, the opening and closing blades are opened in the lower space of the casing, and the expanding excavator is rotated together with the casing to form a trapezoidal shape. Can be excavated.

According to an eighth aspect of the present invention, there is provided a hydraulic cylinder for extending and retracting the fixed overhanging grip and a hydraulic unit for supplying hydraulic oil to the hydraulic cylinder for expanding and driving the opening and closing blades on the ground. The hydraulic cylinders are connected with hydraulic hoses via hydraulic swivels.
With this configuration, the expansion excavator can be controlled by operating the hydraulic unit from the ground, and since the hydraulic swivel is used, the hydraulic oil of the expansion excavator can be used even when the casing is rotated. Can be supplied to the cylinder without any problem.

According to a ninth configuration of the present invention, a frame is installed at the upper end of the casing, and a hose take-up reel that winds up a hydraulic hose that supplies hydraulic oil to the hydraulic swivel and the hydraulic cylinders is installed in the frame. is there.
With this configuration, it is possible to suspend only the expansion excavator to a predetermined depth and supply hydraulic oil to the hydraulic cylinder.

The pile bottom expansion method according to the tenth configuration of the present invention is a method of excavating the ground using a cylindrical casing having a cutting edge formed at the lower end, and constructing a foundation in the casing. A step of removing earth and sand in the casing after excavating the ground, a step of lifting the casing a little to form a space in the lower portion of the casing, and a removably fixed inside of the lower portion of the casing in the casing. A fixed extension grip that is attached to the base part and is driven to extend and contract toward the inner surface of the casing, a bit that is attached to the lower side of the base part and is fixed to a tip part, and the bit Is inserted from the upper part of the casing, and the fixed overhanging grip is attached to the casing. A step of fixing the expansion excavator to the lower end of the casing by extending so as to be pressed against the circumference; and extending the opening / closing blade to project the bit outward from the outer peripheral surface of the casing, thereby expanding the excavation And rotating the device together with the casing to excavate the ground, expanding the diameter of the lower part of the casing and accommodating the excavated earth and sand inside the opening / closing blade, and closing the opening / closing blade to casing the expanding excavation device And a step of constructing a foundation made of concrete in the hole formed by the casing and the expanding excavation device.
With this configuration, the expanded excavator is inserted into the casing, and the earth and sand excavated while forming the expanded hole portion is stored inside the opening and closing blade, and after the expanded opening is formed, the expanded excavator is excavated. It can be taken out with the earth and sand.

The present invention has the following effects.
(1) The expanded excavation device of the first configuration includes a base portion that is detachably fixed to the lower inner side of the casing, and an arm portion that moves the bit linearly outward from the outer peripheral surface of the casing and protrudes. Therefore, when the hole that does not expand is formed by the casing, a load is not applied to the expansion excavation apparatus, and the strength of the casing does not decrease. Moreover, since it is fixed to the casing and rotates together with the casing, the structure can be simplified and can be quickly attached, and since it moves linearly, the diameter can be surely increased.
(2) When the first arm portion and the second arm portion are provided, the stroke of the arm portion can be lengthened, and the diameter of the expanded hole portion formed in the lower portion can be increased even when the diameter of the casing is small.
(3) When the guide rail portion is formed on the inner peripheral surface of the casing, the base portion of the expansion excavator can be suspended by a crane or the like and inserted into the casing from the upper end along the guide rail. The open excavation device can be moved up and down easily by preventing the horizontal displacement.
(4) When the arm portion is constituted by a hydraulic cylinder and the accumulation bucket is provided on the base portion, the excavated earth and sand can be guided along the cylinder rod toward the center of the casing and collected in the accumulation bucket. It can save the trouble of collecting earth and sand.
(5) When the spacer member is detachably provided on the side opposite to the protruding direction of the arm portion of the base portion, when using a large-diameter casing, the spacer member can be attached to the base portion and used. The versatility of the expanded excavator is improved.
(6) In the sixth method of expanding the pile bottom, the expansion excavator provided with the accumulation bucket is inserted from the upper part of the casing and fixed to the lower end, and rotated together with the casing to excavate the ground, Since the expanded excavator is taken out from the upper part of the casing after being shrunk, the excavated excavator is excavated after storing the excavated earth and sand while forming the expanded hole in the accumulation bucket and forming the expanded opening. It can be taken out together with the earth and sand, and the expansion work can be easily performed in a short time.
(7) The expanded excavation device of the seventh configuration is attached to the base part, and is attached to the lower end of the base part and fixedly extended grip that is extended and contracted toward the inner surface of the casing. Since the bit is fixed and has an opening and closing blade that expands the bit outward from the outer peripheral surface of the casing, the fixed overhanging grip is extended to fix the expanding excavator to the casing inner surface, and the opening and closing blade is fixed to the lower part of the casing. The trapezoidal bottom expansion part can be excavated with a bit by opening in the space part and rotating the expansion excavation apparatus together with the casing.
(8) Install a hydraulic cylinder that extends and retracts the fixed overhanging grip and a hydraulic unit that supplies hydraulic oil to the hydraulic cylinder that drives the opening and closing blades to expand. The hydraulic unit and each hydraulic cylinder are connected to the hydraulic swivel. By connecting with a hydraulic hose, the expansion excavator can be controlled by operating the hydraulic unit from the ground, and since the hydraulic swivel is used, the hydraulic oil is supplied even when the casing is rotated. It can be supplied to the hydraulic cylinder of the expansion excavator without any trouble.
(9) A stand is installed at the upper end of the casing, and a hose take-up reel that winds up a hydraulic hose that supplies hydraulic oil to each hydraulic cylinder and a hydraulic hose is installed on the stand, so that only the expansion excavator is at a predetermined depth. The hydraulic oil can be supplied to the hydraulic cylinder by being suspended.
(10) According to the pile bottom expansion method according to the tenth configuration, the expanded excavation device is inserted into the casing, the earth and sand excavated while forming the expanded hole portion is stored in the opening and closing blade, and the expanded opening portion After forming, the expanded excavator can be taken out with the excavated earth and sand. As a result, the expansion work can be easily and safely performed in a short time.

Embodiments of the present invention will be described below.
(First embodiment)
FIG. 1 is a front sectional view of an expanded excavator according to the first embodiment of the present invention, FIG. 2 (A) is a plan view of the expanded excavator, and FIG. 1 (B) is a right side view of the expanded excavator. is there. As shown in FIGS. 1 and 2, the expanded excavation apparatus 1 according to the first embodiment is an apparatus provided at the lower part of a cylindrical casing 3 having a cutting edge 2 formed at the lower end.

  The expansion excavation apparatus 1 is formed in a shape in which a rectangular parallelepiped base portion 4 that is detachably fixed to a lower inner side of a casing 3 and square tubes that are open to the side are arranged in two upper and lower stages. A first arm portion 5 that is extrapolated to the base portion 4 and is movable in the longitudinal direction of the base portion 4, and is inserted movably to the lower portion of the first arm portion 5 to fix the bits 26 to 28 to the tip portion. A rectangular parallelepiped second arm portion 7 that moves linearly to the side and can protrude outward from the outer peripheral surface of the casing 3 is provided.

  Two guide rail portions 8 for guiding the base portion 4 to the lower side of the casing 3 are provided in parallel to the center line of the casing 3 at two opposing positions on the inner peripheral surface of the casing 3. At the lower end portion of the guide rail portion 8, there is a stopper portion 46 formed in a U-shape that opens upward to hold the expanding excavator 1 inserted from above at the lower end portion of the casing 3. 8 is provided so as to cover the lower end.

  Both end portions 9 and 10 of the base portion 4 are formed in a circular arc shape that is convex according to the inner diameter of the casing 3. Further, on the side opposite to the protruding direction of the second arm portion 7 of the base portion 4, spacer members 11 and 12 having the same rectangular cross-sectional shape as the base portion 4 can be attached and detached using fastening members such as bolts. It is fastened to the fastening. As for the spacer members 11 and 12, the edge part by the side of the base part 4 becomes concave, and the other side becomes convex. The length of the base part 4 when the spacer members 11 and 12 are not attached is formed slightly smaller than 1500 mm, and the lengths of the spacer members 11 and 12 are respectively formed as 300 mm and 200 mm. With such a configuration, one spread excavator 1 can be used for a casing having a diameter of 1500 mm, 1800 mm, or 2000 mm.

  Rail guide portions 37 to 40 are formed in the vertical direction on both ends 9 and 10 of the base portion 4 and the end portions on the convex side of the spacer members 11 and 12 so as to cover the guide rail portion 8 and slide up and down. Has been.

  Rectangular through holes 14 and 15 into which the base part 4 and the second arm part 7 are respectively inserted are formed above and below the first arm part 5, and the through holes 14 and 15 are partitioned by a partition plate 16. Yes.

A through hole 13 is formed in the lower center of the base part 4, and a rod fixing part 17 is provided in the upper part of the partition plate 16 so as to protrude from the through hole 13 into the base part 4.
A hydraulic cylinder 18 is provided inside the through hole 14 on the upper side of the base part 4. The base side of the hydraulic cylinder 18 is fixed to one end portion 9 of the base portion 4, and the tip side of the hydraulic cylinder 18 is fixed to the rod fixing portion 17.

  A hydraulic cylinder 19 is provided in the second arm portion 7 disposed in the through hole 15 on the lower side of the base portion 4. The proximal side of the hydraulic cylinder 19 is fixed to one end 9 of the first arm portion 5, and the distal side of the hydraulic cylinder 18 is fixed to the second arm portion 7.

In the upper part of the first arm portion 5, a long hole is formed penetrating vertically through flexible oil supply pipes 20 to 23 that supply hydraulic oil to the hydraulic cylinders 18 and 19.
In addition, at both ends in the longitudinal direction of the upper portion of the first arm portion 5, suspension members that connect the wires when the expanding excavator 1 is inserted into the casing 3 and lowered and then lifted and taken out. 24 are provided.

  The second arm portion 7 includes a bit fixing plate 25 that protrudes from the lower through hole 15 on the lower side of the first arm portion 5 to the other end portion 10 side and is arranged vertically. 25 is provided with one or more, for example, three bits 26-28.

  The bits 26 to 28 are fixed to one side of the bit fixing plate 25 obliquely upward, horizontally, and obliquely downward, but can be attached in different directions depending on the properties of the ground.

  A groove-shaped guide member 29 for transporting the earth and sand excavated by the bits 26 to 28 to the center of the lower part of the expansion excavation apparatus 1 is fixed to the lower part of the bit fixing plate 25. The groove-shaped guide member 29 can move forward and backward together with the bit fixing plate 25.

FIG. 3A is a side view of the expanded excavator, FIG. 3B is a front sectional view showing a state in which the expanded excavator is in use, and FIG. 4 shows a state after use of the expanded excavator. FIG. As shown in FIGS. 3A, 3 </ b> B, and 4, at the lower part of the base part 4, a side wall 30 formed in a cylindrical shape and an openable / closable lid part 31 provided at the lower part of the side wall 30. A stacking bucket 41 including a top plate member 32 provided on the upper portion of the side wall 30 is detachably provided on the base portion 4.
In the side wall 30, a rectangular parallelepiped moving space 47 in which the base portion 4, the first arm portion 5 and the second arm portion 7 can move up and down is formed. The moving space 47 is isolated from the other spaces in the accumulation bucket 41 and is formed so that earth and sand do not enter.
The lid portion 31 of the accumulation bucket 41 is formed with two V-shaped cutout portions 44, and a valve body 45 made of a flexible member such as a rubber plate is provided to cover the cutout portions 44. . One end (shaded portion in FIG. 4) of the valve body 45 is fixed along one side in the circumferential direction of the notch 44, and the other end is in contact with the upper surface of the lid 31.

  When the casing 3 is pushed downward while rotating to one side in the circumferential direction, the earth and sand staying in the lower portion of the casing 3 passes through the notch portion 44 while pushing up the valve body 45 and is accommodated in the accumulation bucket 44. The When the casing 3 is rotated in the reverse direction or when the casing 3 is moved upward, the valve body 45 is not opened and the earth and sand in the accumulation bucket 41 does not spill out.

  The lid portion 31 is formed in an inverted conical shape with the apex protruding downward. The lid portion 31 is provided with a fixing portion 34 that can be opened and closed by an operation member 33 provided on the top plate member 32.

  Next, operation | movement of the expansion excavation apparatus 1 is demonstrated. The expansion excavation apparatus 1 moves the rods of the hydraulic cylinders 18 and 19 forward and backward by feeding hydraulic oil into the oil supply pipes 20 to 23, and the rods advance and retract so that the first arm portion 5 and the second arm portion 7 are linearly moved. The bits 26 to 28 can be projected outward from the outer peripheral surface of the casing.

  As shown in FIGS. 1 and 2, in the initial state of the expansion excavator 1, the rods of the hydraulic cylinders 18 and 19 are contracted, and the first arm 5 and the second arm 7 are also contracted. It has become. The tips of the bits 26 to 28 at this time are arranged closer to the center than the inner peripheral surface of the casing 3.

  When hydraulic pressure is applied to the oil supply pipe 20, the rod of the hydraulic cylinder 18 expands, the first arm portion 5 moves outward in the radial direction of the casing 3, and the bits 26 to 28 protrude outward from the outer peripheral surface of the casing 3. To do. By rotating the casing 3 in this state, it is possible to excavate the earth and sand on the outer side in the radial direction from the outer peripheral surface of the casing 3 with the bits 26 to 28. The excavated earth and sand enters the groove-shaped guide member 29. By continuing excavation, the earth and sand move toward the center of the casing 3 and are accumulated in the accumulation bucket 41.

  Next, when oil pressure is applied to the oil supply pipe 22, the rod of the hydraulic cylinder 19 expands, the second arm portion 7 moves outward in the radial direction of the casing 3, and the bits 26 to 28 move further outward. By rotating the casing 3 in this state, the outer earth and sand can be excavated with the bits 26 to 28.

  After excavation, when hydraulic pressure is applied to the oil supply pipes 21 and 23, the rods of the hydraulic cylinders 18 and 19 contract.

  The rod of the hydraulic cylinder 19 can be extended with the hydraulic cylinder 18 contracted. For example, if the strokes of the hydraulic cylinders 18 and 19 are 40 cm and 60 cm, respectively, the settable expansion radii are three types of 40 cm, 60 cm, and 100 cm. The enlargement width is managed by the operator, and the operator can freely set the enlargement width from the outside of the casing 3.

  As shown in FIGS. 3A and 3B, the stacking bucket 41 can freely move up and down with respect to the base portion 4, and the height position is determined by the bottom surface of the space portion 36. When the height of the space portion 36 is low, the relative position of the stacking bucket 41 with respect to the base portion 4 rises. At this time, the base part 4 moves downward in the movement space part 47 in the accumulation bucket 41. Further, as shown in FIG. 3B, when the height of the space portion 36 is high, the base portion 4 moves upward in the movement space portion 47.

Next, the pile bottom expansion method using the expansion excavation apparatus will be described.
5 (A) to 5 (E) are explanatory views showing a work procedure of the pile bottom expansion method. As shown in FIGS. 5 (A) to 5 (E), the pile bottom expansion method excavates the ground using a cylindrical casing 3 having a cutting edge 2 formed at the lower end, and constructs a foundation in the casing 3. In this construction method, the expansion excavator 1 is used.

(Drilling)
As shown in FIG. 5A, an all-round rotating machine 35 is installed at the site, the casing 3 is rotationally pressed to a specified depth to excavate the ground, and the earth and sand in the casing 3 is removed using a hammer grab 43 To do.

(Preparation for diameter expansion)
As shown in FIG. 5B, the casing 3 is lifted by a necessary stroke based on the expansion plan and supported by the all-around rotating machine 35, and a space 36 is formed in the lower part of the casing 3. The height of the space portion 36 is set to be equal to or higher than the height at which the expansion excavation apparatus 1 is mounted on the casing 3 and is operable.

(Expansion drilling device inserted)
Next, as shown in FIGS. 5B and 5C, the rail guide portions 37 and 40 of the expansion excavator 1 are extrapolated to the guide rail portion 8 of the casing 3 by using a hanging means such as a crane. Then, the rail guide portions 37 and 40 are gradually lowered until they are hooked on the stopper portion. In addition, it is also possible to form a hooking part separately from the stopper part and add a structure for preventing the vertical excavation apparatus 1 from moving up and down relative to the casing 3. For example, if the same length as the guide rail portion 8 at the lower end portion of the rail guide portion is offset in the circumferential direction, the expanding excavation apparatus 1 comes into contact with the stopper portion and stops, and then the casing 3 is turned around. When rotating in the direction, the guide rail portion 8 of the expanding excavator 1 is engaged with the offset portion at the lower end of the rail guide portion and cannot be removed.

(Expansion)
As shown in FIG. 5D, a plate-like operation panel 42 is put on the upper portion of the casing 3. On the plate-like operation panel 42, the opening and closing operation of the oil supply pipes 20 to 23, the supply of hydraulic pressure, or the control of the all-around rotating machine 35 can be performed. By installing an electric panel or display showing these control states, management during the expansion operation can be visually confirmed.

  The first and second arm portions 5 and 7 are expanded and contracted, the bits 26 to 28 are projected by a predetermined length, and the casing 3 is rotated, whereby the surrounding earth and sand are excavated, and the space below the casing 3 is excavated. The diameter of the part 36 can be expanded.

  As shown in FIG. 3 (B), earth and sand are accumulated in the accumulation bucket 41 by performing the expansion work. The expansion work is performed from the upper side of the space 36. The excavated earth and sand are supported so as not to fall by the lower ground that has not yet been expanded, and the earth and sand are efficiently guided to the accumulation bucket 41. As excavation progresses from the upper side to the lower side of the space portion 36, the base portion 4 moves to the lower side in the accumulation bucket 41, but the movement space portion 47 is provided in the accumulation bucket 41. In addition, since the earth and sand do not enter the moving space 47, the earth and sand can be accommodated smoothly.

(Discharge)
As shown in FIG. 5 (E), the first and second arm portions 5 and 7 are contracted to take out the expanded excavator 1 from the upper portion of the casing 3, and the lid portion 31 is opened to discharge the earth and sand. In addition, since the residual slime is also taken in from the notch part 44 of the lower part of the accumulation bucket 41, a complete slime process becomes possible.

(Foundation construction)
A foundation made of concrete is constructed in the hole formed by the casing 3 and the expansion excavator 1. The casing 3 is gradually pulled upward while placing concrete.
In this way, it is possible to construct a foundation whose lower part has an enlarged diameter.
(Second Embodiment)
FIG. 6 is a front sectional view of the expanded excavation apparatus during lifting according to the second embodiment of the present invention, FIG. 7 is a front sectional view of the expanded excavation apparatus during bottom expansion according to the second embodiment, FIG. ) Is a plan view when the expansion excavation apparatus is lifted and lowered, and (B) is a plan view when the expansion excavation apparatus is expanded.
As shown in FIGS. 6 and 7, the expanded excavation apparatus 51 according to the second embodiment of the present invention is an apparatus provided at a lower portion of a cylindrical casing 53 having a cutting edge 52 formed at a lower end portion.

  The expansion excavator 51 includes a base portion 55 that is suspended from the upper portion of the casing 53 by a suspension wire 54 and a plurality of fixed overhanging grips 56 that can be moved forward and backward toward the inner wall of the casing 53. And a hydraulic cylinder 58 having a base end fixed to the center pole 57 of the base portion 55 and the other end fixed to a fixed overhanging grip 56.

  A pedestal 59 is provided at the upper end of the casing 53, and a hydraulic hose 61 from the ground hydraulic unit 60 is guided to the pedestal 59 via a hydraulic swivel 62 so as to be rotatable. The hydraulic hose 63 connected to the hydraulic swivel 62 is guided to the base portion 55 via the hose take-up reel 64, and a part is branched to the hydraulic cylinder 58. The hydraulic hose 63 is further guided to a lower portion of the base portion 55 and supplies hydraulic pressure to a hydraulic cylinder 66 for opening / closing the opening / closing blade 67 via a hydraulic pipe 65. The gantry 59 is provided with a measuring reel 69 for measuring the suspending depth of the expanding excavator 51 by winding and unwinding the measuring tape 68 fixed to the lower end of the hanging wire 54. .

  The opening / closing blade 67 is configured to open and close inward and outward by a vertical hinge 72 provided on a cylindrical frame 71 connected to the lower side of the base portion 55, and a bit 70 is provided at an end portion. It has been. By supplying hydraulic pressure to the hydraulic cylinder 66, it is driven from the closed state in FIG. 6 to the expanded state in FIG. A lid 73 is provided at the bottom of the cylindrical frame 71.

  FIG. 9 is an overall configuration diagram for carrying out a construction method using the expanded excavation device 51 according to the second embodiment. In the figure, 80 is an all-round rotary excavator that excavates while adding a casing 53, 81 is a crawler crane for excavation for ascending and descending a suspension wire 54 that suspends the expansion excavator 51, and 82 is an expansion excavator 51. The dump truck 83 transports the excavated earth and sand, 83 is a hydraulic excavator for loading and leveling the excavated soil, and 84 is for raising the ready-mixed vehicle to the height of the upper part of the all-round rotary excavator 80 when placing the foundation concrete. Ready-to-use car chassis, 85 is a reinforcing bar used to strengthen the strength of foundation concrete placed on site, 86 is a welding machine, 87 is a tremy tube for placing concrete, and 88 is used to generate power for construction work on site The generator 89 to be used is a high-pressure washing machine used for washing work.

Next, the pile bottom expansion method using the expansion excavation apparatus will be described.
(Drilling)
As shown in FIG. 9, an all-round rotary excavator 80 is installed at the site, the casing 53 is rotationally press-fitted to a specified depth, the ground is excavated by the cutting blade 52, and the earth and sand in the casing 53 is hammered (not shown). Remove using a hammer grab 43 in FIG.

(Preparation for diameter expansion)
The casing 53 is lifted by a necessary stroke based on the expansion plan and supported by the all-around rotary excavator 80, and a space is formed in the lower part of the casing 53. The height of the space portion is set to be equal to or higher than the height at which the expansion excavator 51 is attached to the casing 53 and becomes operable.

(Expansion drilling device inserted)
Next, the expanding excavator 51 is lowered to the space at the bottom of the casing 53 by using the crawler crane 81 for excavation. At this time, with the gantry 59 remaining at the upper end of the casing 53, only the expansion excavator 51 is lowered. The lowered position is a position where the lower end of the fixed overhanging grip 56 substantially coincides with the lower end of the casing 53. Next, hydraulic oil is supplied to the hydraulic cylinder 58 by the hydraulic unit 60 so that the fixed overhanging grip 56 advances outward, and the contact surface of the fixed overhanging grip 56 with the inner surface of the casing 53 as shown in FIG. With this frictional force, the expanded excavation device 51 is fixed in an immobile state.

(Expansion)
As shown in FIG. 7, the hydraulic oil is supplied from the hydraulic unit 60 to the hydraulic cylinder 66 through the hydraulic hose 63 and the hydraulic pipe 65, and the opening / closing blade 67 is expanded outward. Initially, since the space portion below the casing 53 has substantially the same diameter as the outer diameter of the casing 53, the degree of expansion of the opening / closing blade 67 is small. Next, the casing 53 is rotated using the all-around rotary excavator 80. As the casing 53 rotates, the expanded excavation device 51 also rotates together, so that the inner periphery of the hole is excavated by the bit 70 provided at the end of the opening / closing blade 67. As the excavation progresses, by opening the opening / closing blade 67, the bottom of the hole can be expanded in a trapezoidal shape as shown in FIG. The earth and sand excavated by the spreading is collected in a space surrounded by the lid 73 and the cylindrical frame 71. An intake hole is provided at the top of the lid 73, and the bottom slime is scooped up from the intake hole and collected.

(Discharge)
When the expansion operation is completed to a predetermined plan value, the hydraulic cylinder 66 is reduced by the hydraulic unit 60 and the opening / closing blade 67 is closed. At the same time, the hydraulic oil in the hydraulic cylinder 58 is also removed, and the fixed overhang grip 56 is moved backward. Thereby, a clearance gap arises between the expansion excavation apparatus 51 and the inner periphery of the casing 53, a fixed state is cancelled | released, and it will be in the state shown in FIG. In this state, the suspension wire 54 is lifted by the crawler crane 81 for excavation, the expanding excavator 51 is taken out from the upper part of the casing 53, the lid 31 is opened, and the earth and sand are discharged.

(Foundation construction)
A reinforcing bar 85 is inserted into the hole formed by the casing 53 and the expansion excavator 51, and concrete is placed to construct a foundation. The casing 53 is gradually pulled upward while placing concrete.
In this way, it is possible to construct a foundation whose lower part has an enlarged diameter.

  In the second embodiment, the hydraulic power source is the ground hydraulic unit 60, and the hydraulic cylinders 58 and 66 inside the expansion excavator 51 are driven via the hydraulic swivel 62. Therefore, the first embodiment As described above, the work on the plate-like operation panel 42 can be unmanned, and a safe work can be performed. Further, it is not necessary to form the guide rail portion 8 in the casing.

  In the second embodiment described above, an example in which four hydraulic cylinders 58 are used as means for expanding and contracting the four fixed overhanging grips 56 as shown in FIG. It can also be driven by two hydraulic cylinders in two stages which are three-dimensionally crossed as a pair. Further, as shown in FIG. 10, opposing fixed overhanging grips 56 each having a taper on the inner peripheral surface thereof are slidably connected with two stages of connecting slide bars 74 and 75, and the inner peripheral surface of the fixed overhanging grip 56. It is also possible to provide an elevating piece 76 having a taper surface that is in contact with the outer periphery thereof, and to connect the connecting slide bar 74 and the elevating piece 76 with a single hydraulic cylinder. In addition, springs 78 and 79 are provided so as to attract the opposing fixed overhanging grips 56. With this configuration, when the hydraulic cylinder 77 is extended, a gap is formed between the fixed overhang grip 56 and the casing 53 as shown in FIGS. 10A and 10B. In the state where the cylinder 77 is contracted, the elevating piece 76 is raised as shown in FIG. 10C and the fixed overhanging grip 56 is pushed outward by the taper surface, and the outer periphery of the fixed overhanging grip 56 is the inner periphery of the casing 53. The expansion excavation device 51 can be fixed to the casing 53.

  The expansion excavation apparatus of the present invention is useful as an expansion excavation apparatus and a pile bottom expansion method for excavating the surrounding ground provided inside a cylindrical drill such as a casing tube used in the all casing method, It is suitable for building foundations for high-rise buildings in the construction field and foundations for bridges in the civil engineering field.

1 is a front sectional view of an expanded excavation device according to a first embodiment of the present invention. (A) is a top view of the expansion excavation apparatus, (B) is a right side view of the expansion excavation apparatus. (A) is a side view of the expansion excavation apparatus, (B) is a front sectional view showing a state in use of the expansion excavation apparatus. It is a front view which shows the state after use of the expansion excavation apparatus. (A)-(E) are explanatory drawings which show the work procedure of a pile bottom expansion construction method. It is a front sectional view at the time of raising and lowering of the expansion excavation device according to the second embodiment of the present invention. It is a front sectional view of the expansion excavation apparatus at the time of bottom expansion according to the second embodiment. (A) is a top view at the time of raising / lowering of the said expansion excavation apparatus, (B) is a top view at the time of the bottom expansion of the said expansion excavation apparatus. It is a whole block diagram for enforcing the construction method using the expansion excavation apparatus which concerns on 2nd Embodiment. The other example in 2nd Embodiment is shown, (a) is a top view of an expansion excavation apparatus, (b) is a front sectional view at the time of raising / lowering of an expansion excavation apparatus, (c) is the expansion excavation apparatus It is a front sectional view at the time of bottom expansion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Expanding excavation apparatus 2 Cutting blade 3 Casing 4 Base part 5 1st arm part 7 2nd arm part 8 Guide rail part 9,10 End part 11,12 Spacer member 13 Through-hole 14,15 Through-hole 16 Partition plate 17 Rod fixing portion 18 Hydraulic cylinder 19 Hydraulic cylinder 20-23 Oil supply pipe 24 Hanging member 25 Bit fixing plate 26-28 Bit 29 Groove-shaped guide member 30 Side wall 31 Lid portion 32 Top plate member 33 Operation member 34 Fixing portion 35 Full circumference Rotating machine 36 Space part 37-40 Rail guide part 41 Stacking bucket 42 Plate-like operation panel 43 Hammer grab 44 Notch part 45 Valve body 46 Stopper part 47 Moving space part 51 Expanding excavator 52 Cutting blade 53 Casing 54 Hanging wire 55 Base unit 56 Fixed overhang grip 57 Center pole 58 Hydraulic cylinder 59 Mounting frame 60 Hydraulic pressure Knit 61 Hydraulic hose 62 Hydraulic swivel 63 Hydraulic hose 64 Hose take-up reel 65 Hydraulic pipe 66 Hydraulic cylinder 67 Opening and closing wing 68 Inspection tape 69 Inspection reel 70 Bit 71 Cylindrical frame 72 Hinge 73 Lid 74, 75 Connecting slide bar 76 Lifting frame 77 Hydraulic cylinder 78, 79 Spring 80 Full-rotation excavator 81 Crawler crane for excavation 82 Dump truck 83 Excavator 84 Ready-mixed vehicle chassis 85 Rebar rod 86 Welding machine 87 Toremy tube 88 Generator 89 High pressure washer

Claims (9)

An expanded excavator provided at the lower part of a cylindrical casing having a cutting edge formed at the lower end,
A base portion detachably fixed to the lower inner side of the casing;
An arm that is attached to the lower side of the base and has a bit fixed to a tip, and moves the bit linearly outward from the outer peripheral surface of the casing ;
The arm portion is attached to the base portion, and a first arm portion that is linearly movable laterally;
A second arm portion that is attached to the first arm portion, fixes the bit to the tip portion, moves linearly to the side, and protrudes outward from the outer peripheral surface of the casing ; A featured exploration rig. A plurality of locations of the inner peripheral surface of the casing, the guide rail portion for guiding the base portion below the casing, according to claim 1, characterized in that it is formed in parallel to the center line of the casing Expanding drilling rig. The arm portion is provided with a guide member for guiding the earth and sand excavated by the bit to the center side of the casing, and an accumulation bucket for accumulating the earth and sand is provided at a position below the arm portion. The expansion excavation apparatus according to claim 1 or 2 , characterized in that: The expansion excavation apparatus according to any one of claims 1 to 3 , wherein a spacer member is detachably provided on a side opposite to a protruding direction of the arm part of the base part. . In the method of excavating the ground using a cylindrical casing with a cutting edge formed at the lower end, and constructing a foundation in the casing,
Removing the earth and sand in the casing after excavating the ground with the casing;
Slightly lifting the casing to form a space in the lower part of the casing;
In the casing, a base part fixed to the lower part of the casing, an arm part attached to a lower side of the base part and having a bit fixed to a tip part, and linearly movable laterally and the arm A step of inserting an expanding excavator provided with an accumulation bucket disposed at a lower position of the part from the upper part of the casing and fixing it to the lower end part;
The arm is extended, the bit protrudes outward from the outer peripheral surface of the casing, the expansion excavator is rotated together with the casing to excavate the ground, and the lower portion of the casing is expanded and excavated. Storing earth and sand in the accumulation bucket;
A step of constructing a foundation made of concrete in the hole formed by the casing and the expansion excavation device after the arm portion is contracted and the expansion excavation device is taken out from the upper part of the casing. Pile-bottom expansion method that is characteristic. An expanded excavator provided at the lower part of a cylindrical casing having a cutting edge formed at the lower end,
A base portion detachably fixed to the lower inner side of the casing;
A fixed overhanging grip attached to the base and driven to extend and contract toward the inner surface of the casing;
An expansion excavation apparatus, comprising: an opening / closing blade attached to a lower side of the base portion, having a bit fixed to a tip portion thereof, and expanding the bit outward from an outer peripheral surface of the casing. A hydraulic cylinder for extending and retracting the fixed overhanging grip and a hydraulic unit for supplying hydraulic oil to the hydraulic cylinder for expanding and driving the opening and closing blades are installed on the ground, and the hydraulic unit and each hydraulic cylinder are connected to a hydraulic swivel. The expansion excavation apparatus according to claim 6 , wherein the expansion excavation apparatus is connected by a hydraulic hose through the pipe. The expansion according to claim 7 , wherein a frame is installed at an upper end of the casing, and a hose take-up reel for winding a hydraulic hose that supplies hydraulic oil to the hydraulic swivel and the hydraulic cylinders is installed on the frame. Open excavation equipment. In the method of excavating the ground using a cylindrical casing with a cutting edge formed at the lower end, and constructing a foundation in the casing,
Removing the earth and sand in the casing after excavating the ground with the casing;
Slightly lifting the casing to form a space in the lower part of the casing;
In the casing, a base part detachably fixed to the lower inner side of the casing, a fixed overhanging grip attached to the base part and driven to extend and contract toward the inner surface of the casing, A spreading excavator equipped with an opening / closing blade attached to the lower side and having a bit fixed to the tip end and expanding the bit outward from the outer peripheral surface of the casing is inserted from the upper part of the casing, and the fixed tension Fixing the expanded excavation device to the lower end of the casing by extending the output grip so as to be in pressure contact with the inner periphery of the casing;
Extending the opening and closing wings, the bit protrudes outward from the outer peripheral surface of the casing, the expansion excavator is rotated together with the casing to excavate the ground, and the lower portion of the casing is expanded and excavated. Containing earth and sand in the open / close wing;
And a step of constructing a foundation made of concrete in a hole formed by the casing and the spread excavation device after closing the opening and closing blade and taking out the spread excavation device from the upper part of the casing. Pile-bottom expansion method that is characteristic.

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