JP2014031622A - Method of burying precast pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely present a supporting strength in tight contact with a solidified foot protection liquid over entire surfaces of protrusions of a precast pile inside of a foot protection part.SOLUTION: A bottom-end precast pile 1 to be used includes annular protrusions 5, 6 which are positioned in a foot protection part of a pile hole. A protection tube 11 to be used is configured by connecting operating rods 15, 15 to an upper end of a tubular substrate 11 covering at least the protrusions 5, 6 of the precast pile 1 and consecutively providing a rubber closing member 13 abutted to a bottom face of the precast pile 1 in a lower end (Figure 1). Along the outer circumference of the precast pile 1, the protection tube 11 is mounted so as to cover the protrusions 5, 6. In such a state, protrusions 4, 5 are positioned in a foot protection part 66 of a pile hole 65 by lowering the precast pile 1 while drilling the pile hole with a drill head 20 similarly to a normal hollow trench pressing fit technique. The drill head 20 is pulled up onto the ground, continuously, the operating rods 15 are pulled onto the ground, and the protection tube 10 is pulled up onto the ground. The protrusions 4, 5 to which mud is not deposited are buried within the foot protection part 66.

Description

  The present invention relates to a ready-made pile embedding method in which a ready-made pile is buried in a pile hole while excavating a pile hole or after excavating a pile hole.

  Conventionally, in the medium excavation method, the excavation rod 70 with the excavation head 20 is inserted into the hollow portion of the ready-made pile 1, the excavation head 20 is protruded from the tip, and the ready-made pile 1 is pushed downward while excavating the pile hole 65. (FIGS. 11A and 11B), before and after placing the ready-made piles 1 and 8 at predetermined positions in the pile hole 65 (FIG. 11C), the excavation rod 70 is moved from the pile hole 65. The piles 1 and 8 were pulled up to the ground 64, and the foundation pile 61 was constructed after the root hardening liquid (cement milk) 67 was solidified (FIG. 11 (d)). Further, in this case, in order to ensure more tip supporting force even in the digging method, a large-diameter root consolidation portion 66 having a large solidification strength is formed at the lower end portion of the pile hole 65, and a protrusion is provided at the lower end portion. Using the ready-made pile 1, the protrusion was positioned at the rooted portion (Patent Document 1).

In this case, in the medium excavation method, the outer diameter of the pile hole 65 is generally set to be equal to or less than the maximum outer diameter of the ready-made piles 1, 8. , 6, the lower surface sides 4 a, 5 a, 6 a of the projections 4, 5, 6 hit the wall of the pile hole 65, so that the outer surface of the ready-made pile 1 and the lower surfaces 4 a, 5 a of the projections 4, 5, 6, In a state where mud 75 is attached to 6a, it is lowered, and the protrusions 5 and 6 with 65 mud 75 may be disposed on the root hardening portion. Moreover, even if it is a case where the pile hole 65 is formed larger than the maximum outer diameter of the ready-made pile 1, if there is a lump of mud in the pile hole 65, the protrusions 4, 5, There was also a possibility that mud adhered to the lower surface side of 6.
Moreover, even in the ready-made pile 1 having no protrusion, mud may adhere to the outer surface and the lower surface of the ready-made pile 1 in the same manner.

  Further, the so-called pre-drilling method in which only the ready-made piles 1 and 8 are buried in the pile hole 65 after excavating the pile hole 65 with the excavation head 20 has the same problem (FIG. 12). That is, in the pre-drilling method, a pile hole 65 having a predetermined structure is excavated by the excavation head 20 (FIGS. 12A and 12B), and then the rooting liquid is discharged from the excavation head 20 (FIG. 11 ( c)), the excavation head 20 is pulled up to the ground 64 to form a pile hole 65 having a rooted portion 66 having a predetermined structure (FIG. 11 (d)), and then the projections 4, 5, 6 are provided in the pile hole 65. The ready-made piles 1 and 8 were lowered and the protrusions 5 and 6 at the lower end of the ready-made pile 1 were positioned in the root-solidifying portion 65, and the foundation pile 61 was constructed after the cement milk solidified (FIG. 11). (E)).

  Also in the case of the so-called pre-drilling method, the pile hole diameter is generally formed larger than the pile diameter, but the ready-made pile 1 may also come into contact with the wall of the pile hole 65 in the same manner.

JP 2002-61178 A

In the conventional case, since the root-setting liquid (cement milk) of the root-solidifying portion 66 is solidified in the state where the mud 75 is attached to the protrusions 4, 5, 6 of the ready-made pile 1, the protrusion protrusions 4, 5 In some cases, the lower surface of 6 did not touch the solidified root solidified solution directly. Therefore, in this case, there is a problem that the function of the root consolidation part 66 is not sufficiently exhibited when the vertical load acting on the ready-made pile 1 is transmitted to the support ground via the root consolidation part 66.
In particular, this was conspicuous in the case of the medium excavation method in which a pile hole diameter equal to or less than the outer diameter of the ready-made pile 1 was set. In the conventional digging method, there was a feature that the ready-made pile was placed so that the outer surface of the ready-made pile was pressed directly on the outer wall of the pile hole with a relatively weak ground. However, there was a tendency to secure as much supporting force as possible, and it was necessary to form a rooted portion in the pile hole and to place a protrusion of the ready-made pile in the rooted portion.
It is considered that the vertical load of the ready-made pile 1 is transmitted from the surface directed downward of the protrusion of the ready-made pile 1 to the supporting ground through the solidified root hardening liquid. Therefore, it is important to increase the area of the surface of the ready-made pile 1 that faces the lower side of the protrusions 4, 5, 6, which is not preferable when mud adheres to the lower surface of the protrusion.

  Therefore, in the present invention, the above-mentioned problem has been solved since the bottom-end ready-made pile and other ready-made piles are buried in a state where the protective cylinder is attached to the protrusion of the bottom-end ready-made pile.

That is, the invention applied to the middle digging method is to connect the lowermost ready-made pile having a protrusion at the lower end and other ready-made piles, while excavating the pile hole, while positioning the protrusion at the rooted portion of the pile hole It is a construction method of installing the ready-made pile, and is a construction method of a ready-made pile characterized by the following configuration.
(1) Attach a protective cylinder so as to cover the protrusion located in the root-sealed portion at the outer periphery of the lower end portion of the pre-made pile at the lowermost front end.
(2) The lower end of the lifting operation rod is fixed to the upper end of the protective cylinder, and the tip of the excavating rod that has passed through the hollow portion of the pile hole protrudes from the lowermost ready-made pile and the tip of the protective cylinder. While drilling the pile hole with the excavation head at the tip of the excavation rod, the lowermost ready-made pile and the protective cylinder are lowered into the pile hole while excavating the pile hole to a predetermined depth.
(3) Next, connect the upper ready-made pile to the lowermost ready-made pile by a predetermined method, add the excavating rod, add the operation rod, and connect the lowermost ready-made pile and the upper ready-made pile. Then, it is lowered together with the protective cylinder.
Thereafter, a predetermined number of ready-made piles, excavation rods, and operation rods are added, and similarly, the ready-made piles and the protective cylinder are lowered into the pile holes.
(4) If the pile hole has been excavated to a predetermined depth and the rooted portion is formed at the lower end of the pile hole, or before the rooted portion is formed, the necessary projections of the ready-made pile are consolidated. The ready-made pile is lowered so as to be located in the part.
(5) The excavation rod is lifted to the ground simultaneously with the descent of the ready-made pile or before and after the descent of the ready-made pile.
(6) In a state where the ready-made pile reaches a predetermined depth, the ready-made pile is held on the ground, the operation rod is pulled up on the ground, and only the protective cylinder is attached to the outer periphery of the ready-made pile and the pile hole. The lower edge of the protective cylinder is positioned at least above the protrusion of the ready-made pile positioned in the root-fixed portion.
(7) Install the ready-made pile in the pile hole as described above.

In addition, the invention applied to the pre-digging method excavates a pile hole having a rooted portion formed at the lower end portion, and connects the lowermost ready-made pile having a protrusion at the lower end portion and other ready-made piles into the pile hole. It is a construction method for burying and installing the projections in the roots of the pile holes, and is a construction method for a ready-made pile characterized by the following configuration.
(1) The pile hole is excavated by a conventional arbitrary method to form a rooted portion at the lower end of the pile hole.
(2) Attach a protective cylinder so as to cover the protrusion located in the root-clamping portion on the outer periphery of the lower end portion of the ready-made pile at the lowermost end.
(3) The lower end of the operating rod for lifting is fixed to the upper end of the protective cylinder, and the ready-made pile at the lowermost end and the protective cylinder are lowered into the pile hole.
(4) Subsequently, the predetermined pile is connected to the lowermost ready-made pile, and the operation rod is added to the lowermost ready-made pile and the upper ready-made pile to connect the protection pile. Lower the tube in the same way. Thereafter, a predetermined number of ready-made piles and operation rods are added, and similarly, the ready-made pile and the protective cylinder are lowered into the pile holes.
(5) Install the lowermost ready-made piles and other ready-made piles so that the necessary projections of the lowermost ready-made piles are located in the rooting portion.
(6) In a state where the ready-made pile reaches a predetermined depth, the ready-made pile is held on the ground, the operation rod is pulled up on the ground, and only the protective cylinder is attached to the outer periphery of the ready-made pile and the pile hole. The lower edge of the protective cylinder is positioned at least above the protrusion of the ready-made pile positioned in the root-fixed portion.
(7) Install the ready-made pile in the pile hole as described above.

Moreover, in each said invention, it is the burying construction method of the ready-made pile characterized by having formed as follows.
(1) When burying, the lower end of the protective cylinder is positioned below the lowermost protrusion formed on the shaft portion of the lowermost ready-made pile,
(2) A closing member for closing the gap between the shaft portion of the ready-made pile and the inner surface of the protection cylinder is continuously provided at the lower end of the protection cylinder.

  According to this invention, since the protective cylinder covers the outer surface and the lower surface of the ready-made pile, the outer surface of the ready-made pile and the solidified root-setting liquid are in close contact with each other in the rooting portion, and the vertical load can be reliably transmitted to the supporting ground. it can. In particular, when a protrusion is formed on the ready-made pile located at the lowermost end and the protrusion is positioned at the root consolidation part of the pile hole, the entire surface of the protrusion is in close contact with the solidified root-setting liquid, so that the vertical load is The pressing force acting downward from the lower surface and the pressing force acting upward from the upper surface of the protrusion when a pulling force is generated can be efficiently exhibited, and the supporting force of the entire foundation pile structure can be expanded.

FIG. 1 is a protective cylinder used in the practice of the present invention, (a) is a front view, (b) is a longitudinal sectional view, (c) is an AA sectional view, and (d) is a BB sectional view. . FIG. 2 is a front view of a ready-made pile used in the embodiment of the present invention. 3A and 3B are excavation heads used in the practice of the present invention. FIG. 3A is a front view and FIG. 3B is a right side view. 4A and 4B are excavation heads used in the practice of the present invention. FIG. 4A is a plan view and FIG. 4B is a bottom view. FIGS. 5A to 5F are longitudinal sectional views for explaining the excavation method (inner excavation method) of the present invention. FIG. 6 shows a non-rotating state in which the excavation head is connected to the excavation rod, (a) is a front view, and (b) is a right side view. FIG. 7 is a state in which the excavation head is connected to the excavation rod, (a) is a front view in a normal excavation state, and (b) is a front view in an enlarged excavation state. FIG. 8 shows a non-rotating state in which the excavation head is connected to another excavation rod, (a) is a front view, and (b) is a right side view. FIG. 9 is a state in which the excavation head is connected to another excavation rod, (a) is a front view in a normal excavation state, and (b) is a front view in an enlarged excavation state. 10 (a) to 10 (f) are longitudinal sectional views for explaining another excavation method (first excavation method) of the present invention. FIGS. 11A to 11D are longitudinal sectional views for explaining a conventional excavation method (intermediate excavation method). 12 (a) to 12 (e) are longitudinal sectional views for explaining a conventional excavation method (preliminary excavation method).

1. Configuration of ready-made pile 1

(1) The lowermost ready-made pile 1 used in the present invention has an upper shaft portion (thick diameter) 2 connected to an upper ready-made pile 8 and a lower shaft portion (thin diameter) 3 connected continuously. An annular projection 5 having a diameter D ₃ (about 5 cm above the surface) larger than that of the upper shaft portion 2 is formed on the step portion of the shaft portion 2 and the lower shaft portion 3. The annular projections 4 and 6 having the same outer diameter D ₃ are formed on the upper shaft portion 2 and the lower shaft portion 3, respectively.
Here, the projection 6 of the lower shaft portion 3 and the annular projection 5 of the stepped portion are planned to be positioned at the root-fixing portion 66.

(2) The ready-made pile 8 other than the ready-made pile 1 at the lowermost end uses a straight ready-made pile 8 having the same outer diameter as that of the upper shaft portion 2 of the ready-made pile 1 at the lowermost end.
The ready-made piles 8 other than the ready-made pile 1 at the lowermost end may adopt either a straight normal round pile, a node pile provided with an annular protrusion over its entire length, or other special-shaped ready-made piles. When using a ready-made pile having protrusions such as a joint pile, it is desirable that the outer diameter of the largest protrusion is approximately the same as the outer diameter of the annular protrusion of the lowermost ready-made pile.

(3) At the lowest ready-made pile 1,
The outer diameter of the lower shaft 3 is D ₁
The outer diameter of the upper shaft 2 is D ₂
The outer diameter of the annular projections 4, 5, 6 is set to D ₃
And

2. Configuration of protective cylinder 10

(1) the outer diameter _{D 11,} constitutes a tubular support 11 from the steel pipe inner diameter _{D 12.} The inner diameter _{D 12} is slightly to larger diameter than the outer diameter _{D 3} of the annular projection 4, 5 and 6 ready pile 1 the lowermost used.
Flexible resin material having an inner diameter D ₁₃ at a lower end inner surface of the tubular substrate 11 (e.g., rubber-like material) to secure the donut-shaped closing member 13 made. Outer diameter D ₁₁ is to be raised to the ground 64 through the Kuiana 65, a slightly smaller diameter than the diameter D ₀ of Kuiana 65 drilling plan.
The outer diameter D ₁₁ is the diameter D ₀ and the same diameter or Kuiana 65 slightly as a large diameter, the lower end of the tubular support 11 may also be dependent functions of friction cutter. In this case, as slightly smaller diameter than the diameter D ₀ of Kuiana 65 outer diameter D ₁₁ of the upper and middle portion of the tubular support 11, the diameter D of Kuiana 65 outer diameter D ₁₁ of the lower end of the tubular support 11 The diameter can be the same as ₀ or slightly larger.

(2) Further, the lower ends of the operating rods 15 and 15 are connected to the upper end of the cylindrical base 11. Operating rod 15 is a plurality in the rotational symmetrical positions in plan view, the operating rod 15, for example, the outer diameter _{D 11} of the tubular substrate, for 1050 mm, consist thickness 12.6mm about PC bars . The operating rod 15 is preferably formed so as not to protrude from the outer wall (diameter D ₁₁ ) of the cylindrical base 11. The protective cylinder 10 is configured as described above.

(3) Moreover, in the above, although the operation rod 15 used the PC steel rod, if there is a function which winds up the cylindrical base | substrate 11 and raises a cylindrical base | substrate (protection cylinder) from the front-end | tip part of the pile hole 65 to the ground, it will be material. Is optional. For example, a material softer than a PC steel rod such as a steel wire can be used (not shown).

3. Drilling head 20

(1) The excavation head 20 includes a head main body 22 connected to the excavation rod 70, and excavation arms 40 and 40 attached to the head main body 22 by a horizontal shaft 26 (FIGS. 3A and 3B).

(2) The head main body 22 includes a substantially rectangular parallelepiped main body upper portion 23 and a main body flat portion 31 continuous below the main body upper portion 23.
The main body upper part 23 has a rectangular parallelepiped lower part formed in a semicircular shape, and the lower part has a shape like a half-divided cylinder. The four side surfaces of the upper part 23 of the main body are defined as one side surfaces 24 and 24 opposed to each other, and the other side surfaces as other side surfaces 24a and 24a. A connecting portion 25 connected to the excavation rod 70 is provided at the upper end portion of the main body upper portion 23, a horizontal shaft 26 is provided on one side surface (semicircle side) 24, 24 of the main body upper portion 23, and an excavating arm 40 is provided on the horizontal shaft 26. , 40 is connected to the upper end of 40 in a freely rotatable manner. In addition, spiral blades 27 and 27 formed so as to be continuous with the lower end of the spiral blade 71 of the excavation rod 70 are provided on the other side surfaces (side surfaces on which the horizontal shaft 26 is not provided) 24a and 24a.
The main body flat portion 31 has one side 32 as a surface continuing from one side 24 of the main body upper portion 23 and another side 32a as a surface following the other side 24a of the main body upper portion 23. One aspect 32 of the main body flat portion 31 gradually broadens obliquely upper, middle and lower portions has a same width D _21. Further, another aspect 32a of the main flat portion 31 has an upper end formed so as to gradually wide from (lower edge of the upper body 23) to the lower end is narrowed is formed in the D ₂₂ at the lower end. Therefore, the lower surface 33 of the main body flat portion 31 is formed with a plane of “length D ₂₁ × length D ₂₂ ”.
Protrusions 34 having slopes 35 gradually moving downward from the central part are formed on both sides in the D ₂₁ direction on the lower surface 33 of the main body flat part 31, and horizontal surfaces 36 are formed at both ends of the projecting part 34. Fixed excavation blades 38 and 38 are fixed downward on the lower surface 33 of the main body flat portion 31, the slope 35 of the projection 34, and the horizontal surface 36, respectively. Fixed digging edge 38, the cutting edge is in a generally inverted U-shape, the length D ₂₂ direction, two cutting edges are formed.

(3) The excavation arm 40 includes an upper part 41 connected to the horizontal shaft 26, a lower part 43 having moving excavation blades 45, 45 at the lower end, and an intermediate part 42 connecting the upper part 41 and the lower part 43. When viewed from the front (on the one side surface 24 side of the main body upper portion 23), the intermediate portion 42 side of the upper portion 41 is formed so that the width gradually decreases and reaches the intermediate portion 42. The lower portion 43 is formed so as to gradually increase in width from the intermediate portion 42 and has a maximum width at the lower end portion.
Further, when viewed from the side (on the other side 24a side of the main body upper portion 23), the excavation arms 40 are formed with substantially the same width, and the “intermediate portion 42” extends from the “lower side of the upper portion 41” to the one side surface 24 of the head main body 22. 32 is bent and inclined so that the two excavating arms 40 and 40 approach each other. Furthermore, the “lower part 43” of the excavating arm is bent and inclined toward the lower outer side so that the excavating arms 40 are separated from each other. At the lower end of the excavating arm 40, moving excavating blades 45, 45 facing the lower outside along the inclination of the “lower part 43” are connected.
Three movable excavating blades are provided, and when the excavating arm 40 swings in the forward rotation, the outermost moving excavating blade 45A is the longest (the tip is positioned downward), and the innermost moving The excavating blade 45C is the shortest (the tip is positioned upward), and the intermediate moving excavating blade 45B is positioned between the moving excavating blades 45A and 45C (FIGS. 3, 4, 6, and 7).
Further, a side of the excavation arm 40 that swings during normal excavation is defined as one side surface 44, and the other side is defined as another side surface 44a. The stirring plate 47 is fixed to the height from the intermediate part 42 to the lower part 43 on one side 44 of the excavating arms 40, 40.

(4) At the intermediate portion 42 of the excavating arms 40, 40, a frame-like stopper frame 51 is projected from the other side surface (side surface opposite to the side where the stirring plate is provided) 44a. The stopper frame 51 includes two support members 53, 53 projecting from the excavating arm 40 and a stopper bar 52 that connects the tips of both support members 53. The stopper bar 52 and the support members 53, 53 are substantially connected to each other. It is formed in a letter shape. The stopper bar 52 has the same direction as the axial direction of the excavating arm 40, but is set to have a slight angle.
Further, an upper projection 48 is provided on the upper end of the excavating arm 40 so as to face upward.

(5) When the excavation head 20 rotates forward and the excavation arms 40 and 40 are swung, they are swung at a predetermined angle to excavate the shaft portion 66a of the pile hole 65 (FIG. 7A). )). A stopper receiver 56 for locking the stopper bar 52 of the stopper frame 51 of the excavating arm 40 is provided on the main body flat portion 31 of the head main body 22 so as to maintain the swing angle of the excavating arm at that time.
Further, the excavation head 40 rotates forward, the excavation arms 40 and 40 further swing, swing at a predetermined angle, and the pile hole 65 is expanded and excavated (FIG. 7B). The upper protrusion 48 of the excavating arm 40 abuts on one side surface 24 of the main body upper portion 23 of the head body 22 so that the excavating arm 40 swings at that time, and the excavating arm 40 swings more greatly. A first stopper projection 57 that regulates the projection is provided. At this time, a second stopper projection 58 that abuts the intermediate portion 42 of the excavating arm 40 and restricts the excavating arm 40 from swinging further is provided on the main body flat portion 31 of the head main body 22. To do.
Further, a spring is provided in a direction protruding from the one side surface 32 on one side surface 32 of the main body flat portion 31 of the head main body 22 so that the excavation head 40 rotates forward and maintains the swing angle at which the pile hole 65 is enlarged and excavated. A protrusion / depression projection 59 urged by is provided. In this state, the protruding and protruding protrusions 59 are in a protruding state and are fitted into recesses (not shown) provided on the back side of the excavating arm 40 (side facing the head main body 22). Inadvertent pressurization during forward rotation prevents it from returning. If the excavation head 40 is temporarily stopped and the excavation head 40 is pressed against the bottom of the pile hole, the movable excavation blades 45 and 45 of the excavation arm 40 are pressurized, and the distance between the tips of the excavation arm 40 is increased. The back surface of the arm can get over the protrusions and the excavation arm 40 can be returned to the other side.

4). Drilling method (medium digging method)

(1) The protective cylinder 10 is mounted so as to cover the protrusions 5 and 6 and the protrusions 4 located in the root hardening part 66 at the outer periphery of the lower end part of the ready-made pile 1 at the lowest end. In this case, the closing member 13 at the lower end of the protective cylinder 10 covers the lower surface 1 a of the ready-made pile 1. The excavation rod 70 with the excavation head 20 attached to the tip is passed through the hollow portion of the ready-made pile 1 (FIG. 6), the excavation arms 40, 40 of the excavation head 20 are taken out from the lower end of the ready-made pile 1, and the excavation rod 70 (excavation head 20 ) Is rotated forward (FIG. 7 (a)) and lowered while excavating the lower side of the ready-made pile 1 (FIG. 5 (a)).
At this time, the ready-made pile 1 and the operation rod 15 of the protection cylinder 10 are held on the ground 64. When the pile hole 65 is deep, the ready-made pile 8, the excavation rod 70, and the operation rods 15 and 15 are lowered to the ready-made pile 1 while being added.

(2) When the predetermined depth is reached, the swing angle of the excavation arm 40 of the excavation head 20 is increased (FIG. 7B), and the excavation head 20 is greatly projected from below the ready-made pile 1, The root consolidation portion 66 having an enlarged diameter of 65 is excavated (FIG. 5B).

(3) When a predetermined root consolidation part 66 is excavated, the root consolidation liquid 67 is discharged from the lower end of the head main body 23 of the excavation head 22, and the root consolidation part excavation head 22 together with the excavation rod 70 is brought to the ground 64. Pull up (FIG. 5C).

(4) At the same time as or before and after the excavation head 22 is pulled up, if the root-setting liquid 67 is filled in the root-setting part 66, the ready-made pile 1 is installed at a predetermined depth (FIG. 5 (d)). . Thereafter, only the protective cylinder 10 is pulled up by pulling the operating rod 15 on the ground 64 (FIG. 5E).

(5) In this ready-made pile 1, the protrusions 5 and 6 are located in the rooting portion 66, but the protrusion 5, 6 and 6 are not attached to the protrusions 4, 5 and 6 and the lower surface 1 a of the ready-made pile 1. 6, the lower surfaces 5 a and 6 a, the entire protrusions 4 and 5, and the lower surface 1 a are contained in the root hardening liquid 67 (FIG. 5E).
Therefore, after the root hardening liquid 67 is solidified, the foundation pile structure 60 is configured. In the foundation pile structure 60, since the projections 5 and 6 and the lower surface 1a of the ready-made pile 1 are in close contact with the solidified root-solidifying liquid 67, the vertical load is reliably transmitted to the root-solidifying portion 66, and the vertical load is reliably supported by the supporting ground. The

5. Drilling method (pre-drilling method)

(1) The excavation rod 70 attached to the tip of the excavation head 20 is rotated forward (FIG. 7A), and the shaft portion 66a of the pile hole 65 is excavated (FIG. 10A). The swing angle of the excavation arm 40 of the excavation head 20 is increased (FIG. 5B), and further rotated forward to enlarge the excavated portion 66 of the pile hole 65 (FIG. 10B).

(2) When the shaft portion 66a and the root consolidation portion 66 of the pile hole 65 of a predetermined design are constructed, the inside of the root consolidation portion 66 is discharged by the excavation head 20 while discharging the root consolidation liquid 67 from the lower end of the excavation head 20. Repeatedly and stirred (FIG. 10 (c)), the pile hole 65 filled with the root hardening liquid 67 in the root fixing part 66 is constructed, and then the excavation head 20 is pulled up (FIG. 10 (d)).

(3) Subsequently, the protective cylinder 10 is mounted so as to cover the protrusions 5 and 6 and the protrusion 4 positioned in the root-clamping portion 66 on the outer periphery of the lower end portion of the ready-made pile 1 at the lowermost end. In this case, the closing member 13 at the lower end of the protective cylinder 10 covers the lower surface 1 a of the ready-made pile 1. The ready-made pile 1 is lowered together with the protection cylinder 10 in the pile hole 65, and the ready-made pile 1 and the protection cylinder 10 are connected to each other while connecting the other ready-made piles 8 and the operation rods 15 and 15 according to the depth. It is installed at a depth (FIG. 10 (e)).

(4) After that, if only the protective cylinder 10 is pulled by pulling the operating rod 15 on the ground 64 and lifted up, this ready-made pile 1 has the projections 5 and 6 positioned in the root-fixing portion 66, but the projection 4, 5, 6 and the lower surface 1a of the ready-made pile 1 are not attached to the mud, and the lower surfaces 5a and 6a of the protrusions 5 and 6 as well as the whole of the protrusions 4 and 5 and the lower surface 1a are contained in the rooting liquid 67 ( FIG. 5 (f)).
Therefore, after the root hardening liquid 67 is solidified, the foundation pile structure 60 is configured. In the foundation pile structure 60, as in the case of the medium excavation method, the protrusions 5 and 6 and the lower surface 1a of the ready-made pile 1 are in close contact with the solidified root-setting liquid 67. The load is reliably supported by the supporting ground.

6). Other embodiment (1) In the said embodiment, although the case where it has the protrusions 4, 5, and 6 in the ready-made pile 1 of the lowest end is optimal, even if it is a straight-shaped ready-made pile, it is outside by the protection cylinder 10. Since mud does not adhere to the side surface and the lower end 1a, a sufficient effect can be exhibited (not shown).

(2) Further, in the above embodiment, the root consolidation portion 66 of the pile hole 65 is expanded and excavated, but it can also be formed to have the same diameter as the shaft portion 66a (not shown).

(3) Moreover, although the protection cylinder 10 was pulled up to the ground 64 in the above embodiment, the protection cylinder 10 can be stopped in the shaft portion 66a of the pile hole 65 (not shown). In this case, the cylindrical base body 11 of the protective cylinder 10 may be pulled up to a position above the root-fixing portion 66 (that is, positioned at the shaft portion 66a of the pile hole 65). More precisely, the lower edge of the cylindrical base body 11 of the protective cylinder 10 is pulled up so as to be positioned at least above the protrusions 6 and 5 of the ready-made pile 1 positioned in the root-fixing portion 66.

(4) In the above embodiment, the moving excavation blade 45C of the excavation head 20 has the longest moving excavation blade 45A located at the outermost side when the excavation arm 40 swings in the forward rotation, and the movable excavation blade 45B. Although it formed short according to the moving excavation blade 45A, it can also be set as another structure. For example, in the case of three, the movable excavating blades 45A and 45C on both sides can be formed long (the tip is positioned downward) and the intermediate movable excavating blade 45B can be formed short (the tip is positioned upward) (FIG. 8). , FIG. 9). In this case, the operation of the excavation head 20 is the same, and can be used in the same manner in each of the above embodiments.

1 Ready-made pile (lower pile)
DESCRIPTION OF SYMBOLS 1a Lower surface 2 of ready-made pile Upper shaft part 3 Lower shaft part 4, 5, 6 Protrusion 4a, 5a, 6a Lower surface of protrusion 8 Ready-made pile (upper pile)
10 protective cylinder 11 cylindrical substrate (protective cylinder)
13 Blocking member (protection cylinder)
15 Operation rod (protection cylinder)
20 Excavation head 22 Head body (Excavation head)
23 Upper body (head body)
24 One side surface 24a of the upper part of the main body 24a Other side surface of the upper part of the main body 25 Connecting portion (head main body)
26 Horizontal axis 27 Spiral splash (head body)
31 Main body flat part (head main body)
32 One side surface 32a of the main body flat portion 32a The other side surface of the main body flat portion 33 The lower surface 34 of the main body flat portion The protrusion 35 on the lower surface of the main body flat portion The slope 36 of the protrusion 36 The horizontal surface 38 of the protrusion A fixed excavating blade (head main body)
40 Excavation arm 41 Upper part of excavation arm 42 Intermediate part of excavation arm 43 Lower part of excavation arm 44 One side surface of excavation arm 44a Another side surface of excavation arm 45 Moving excavation blade (excavation arm)
47 Stirring plate (excavation arm)
48 Upper projection (excavation arm)
51 Stopper frame (excavation arm)
52 Stopper Bar Stopper Bar 53 Stopper Frame Support Material 56 Stopper Receiver (Head Body)
57 First stopper protrusion (head body)
58 Second stopper protrusion (Head body)
59 Intrusion protrusion (head body)
60 Foundation pile structure 61 Foundation pile structure (conventional example)
64 Ground 65 Pile hole 66 Pile hole root consolidation part 66a Pile hole shaft 67 Root consolidation liquid 70 Drilling rod 71 Spiral splash 75 Mud

Claims (3)

By connecting the bottom-most ready-made pile having a protrusion at the lower end and other ready-made piles, while excavating the pile hole, the protrusion is positioned at the root-fixed portion of the pile hole and the ready-made pile is installed. A method for burying a ready-made pile characterized by the following configuration.
(1) Attach a protective cylinder so as to cover the protrusion located in the root-sealed portion at the outer periphery of the lower end portion of the pre-made pile at the lowermost front end.
(2) The lower end of the lifting operation rod is fixed to the upper end of the protective cylinder, and the tip of the excavating rod that has passed through the hollow portion of the pile hole protrudes from the lowermost ready-made pile and the tip of the protective cylinder. While drilling the pile hole with the excavation head at the tip of the excavation rod, the lowermost ready-made pile and the protective cylinder are lowered into the pile hole while excavating the pile hole to a predetermined depth.
(3) Next, connect the upper ready-made pile to the lowermost ready-made pile by a predetermined method, add the excavating rod, add the operation rod, and connect the lowermost ready-made pile and the upper ready-made pile. Then, it is lowered together with the protective cylinder.
Thereafter, a predetermined number of ready-made piles, excavation rods, and operation rods are added, and similarly, the ready-made piles and the protective cylinder are lowered into the pile holes.
(4) If the pile hole has been excavated to a predetermined depth and the rooted portion is formed at the lower end of the pile hole, or before the rooted portion is formed, the necessary projections of the ready-made pile are consolidated. The ready-made pile is lowered so as to be located in the part.
(5) The excavation rod is lifted to the ground simultaneously with the descent of the ready-made pile or before and after the descent of the ready-made pile.
(6) In a state where the ready-made pile reaches a predetermined depth, the ready-made pile is held on the ground, the operation rod is pulled up on the ground, and only the protective cylinder is attached to the outer periphery of the ready-made pile and the pile hole. The lower edge of the protective cylinder is positioned at least above the protrusion of the ready-made pile positioned in the root-fixed portion.
(7) Install the ready-made pile in the pile hole as described above. Excavating a pile hole having a rooted portion formed at the lower end, and burying the pile hole in the pile hole while connecting the lowermost ready-made pile having a protrusion at the lower end and other ready-made piles, A method of laying a pre-made pile, which is constructed as follows.
(1) The pile hole is excavated by a conventional arbitrary method to form a rooted portion at the lower end of the pile hole.
(2) Attach a protective cylinder so as to cover the protrusion located in the root-clamping portion on the outer periphery of the lower end portion of the ready-made pile at the lowermost end.
(3) The lower end of the operating rod for lifting is fixed to the upper end of the protective cylinder, and the ready-made pile at the lowermost end and the protective cylinder are lowered into the pile hole.
(4) Subsequently, the predetermined pile is connected to the lowermost ready-made pile, and the operation rod is added to the lowermost ready-made pile and the upper ready-made pile to connect the protection pile. Lower the tube in the same way. Thereafter, a predetermined number of ready-made piles and operation rods are added, and similarly, the ready-made pile and the protective cylinder are lowered into the pile holes.
(5) Install the lowermost ready-made piles and other ready-made piles so that the necessary projections of the lowermost ready-made piles are located in the rooting portion.
(6) In a state where the ready-made pile reaches a predetermined depth, the ready-made pile is held on the ground, the operation rod is pulled up on the ground, and only the protective cylinder is attached to the outer periphery of the ready-made pile and the pile hole. The lower edge of the protective cylinder is positioned at least above the protrusion of the ready-made pile positioned in the root-fixed portion.
(7) Install the ready-made pile in the pile hole as described above. It formed as follows, The embedding construction method of the ready-made pile of Claim 1 or Claim 2 characterized by the above-mentioned.
(1) When burying, the lower end of the protective cylinder is positioned below the lowermost protrusion formed on the shaft portion of the lowermost ready-made pile,
(2) A closing member for closing the gap between the shaft portion of the ready-made pile and the inner surface of the protection cylinder is continuously provided at the lower end of the protection cylinder.

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