JP5753205B2 - Casting concrete pile construction method - Google Patents

Description

The present invention relates to a method for constructing cast-in-place concrete piles, and relates to a cast-in-place cast-in-place with a node that is spirally continuous in the axial direction of the pile body on the outer periphery of the pile body and an enlarged joint that is larger in diameter and thicker than the pile body. Concrete piles can be constructed very efficiently and easily.

  Conventionally, as a method of constructing foundation piles with cast-in-place concrete in the ground, a plurality of nodes are attached to the outer periphery of the pile body to increase the frictional force with the ground around the piles to ensure the support capacity of the piles There is a known construction method for cast-in-place concrete piles with knots.

  For example, in Patent Document 1, after drilling a pile hole having a plurality of enlarged diameter portions at arbitrary intervals on a hole wall by a screw auger having an enlarged blade that is enlarged by earth pressure resistance between screw blade pieces. A mortar or cement milk columnar body having a plurality of nodes is formed by placing mortar or concrete in the pile hole, and a prefabricated pile with a node is inserted into the uncured mortar column body and the mortar column A method of creating a cast-in-place concrete pile with a knot by associating a knot of the body with a knot of a ready-made pile with a knot is described.

  In Patent Document 2, a thin-walled cylindrical tube is built in the excavation hole for driving a pile, and a dedicated molding machine is inserted into the thin-walled cylindrical tube, and the thin-walled cylindrical tube is corrugated by the molding machine. A method for constructing a nodal cast-in-place concrete pile made of a thin-walled cylindrical tube and concrete is disclosed.

Japanese Patent Publication No. 60-35489 JP 2000-1849 A Japanese Patent Publication No. 60-26887

  However, each construction method uses a dedicated machine, and various operations such as excavation of pile holes, formation of enlarged diameter parts to be knots, and placement of concrete are performed in independent processes. There were problems such as inferiority.

  Moreover, there is not much known a method for efficiently constructing a knotted pile provided with a spiral-like knot on the outer periphery of a column-like pile main body by cast-in-place concrete.

This invention was made in order to solve the above subject, and it aims at providing the construction method of the cast-in-place concrete pile which enabled it to construct a cast-in-place cast-in-place concrete pile very efficiently and easily. Is.

  The present invention uses a pile construction casing having an enlarged blade integrally attached to a lower end portion of a casing main body and a bottom cover detachably attached, and a spiral continuous node around a columnar pile main body. It is the invention of the construction method of the cast-in-place concrete pile and the casing for pile construction which enabled it to construct the cast-in-place concrete pile with a node efficiently and easily.

  In addition, a method for constructing cast-in-place concrete piles that can easily construct an enlarged node with a diameter larger than that of the pile main body at any position in the axial direction of the pile main body, such as the tip or intermediate portion of the pile main body, and It is an invention of a casing for pile construction.

  According to the present invention, the pile construction casing is press-fitted (penetrated) into the ground to a predetermined depth while rotating the pile construction casing. While pulling out gradually, simultaneously pulling out the casing for pile construction, the concrete in the casing body is placed in the lower end of the casing body in the columnar cavity and spiral cavity formed by the casing body and the enlarged blades. The cast-in-place concrete pile with a knot with a spiral continuous knuckle on the outer periphery of the columnar pile body is formed extremely efficiently and easily by flowing out and filling in the cavity and solidifying in the cavity. be able to.

  In addition, by pulling out a predetermined amount of the pile construction casing without rotation (in a non-rotating state), a cavity is formed below the casing body by the casing body and the enlarged blades, and at the same time, the concrete in the casing body is placed in the cavity. By flowing out and solidifying, an enlarged node having a diameter larger than that of the pile main body and thicker can be easily formed at an arbitrary position in the axial direction of the pile main body such as a tip portion or an intermediate portion of the pile main body.

  In this case, when the pile construction casing is pulled out while rotating the pile construction casing in the reverse direction by pulling out the integral multiple of the installation interval L of the blade construction of the enlargement blade without rotation, the blade section of the enlargement blade is the casing for pile construction. Passes through the spiral cavity formed by the blades of the enlarged blades.

  Thereby, the cavity part which continues in a spiral shape can be reliably formed around the columnar cavity part. These operations can be easily achieved by managing the press-fitting speed, pull-out speed and rotational speed of the pile construction casing.

  In addition, the press-fitting speed and pull-out speed of the pile construction casing and the rotation speed of the pile construction casing are the ground conditions, the diameter of the casing body (especially the expansion blades), the interval L between the blade portions of the expansion blades (see FIG. 2), etc. Can be determined. For example, if the interval L between the enlarged blades is about 160 mm to 170 mm and the penetration is about 1 m per minute, the pile construction casing may be rotated about 6 revolutions per minute.

  Moreover, the casing for pile construction can be made into a simple structure, and a steel pipe etc. can be utilized especially for a casing main body. In addition, the lower end of the casing body is supported via a steady rest, and the press-fitting (penetration) speed and pull-out speed of the pile construction casing and the rotation speed of the pile construction casing are kept constant, thereby expanding the blade section of the enlarged blade. The spiral cavity can be surely formed around the columnar cavity by rotating up and down while rotating at the same position during press-fitting and pull-out, so that the concrete flowing out from the lower end of the casing body is spiraled. Since it fills in the shape-shaped cavity part reliably, the spiral-shaped node part which continues at a fixed space | interval can be easily formed in the outer periphery of a pile main body.

  The pile construction casing is installed on a heavy construction machine equipped with a leader that supports the pile construction casing vertically and an auger motor that presses into the ground while rotating the pile construction casing. The auger motor follows the leader. By controlling the speed of raising and lowering and the rotation speed of the auger motor, the press-fitting speed, the drawing speed and the rotation speed of the pile construction casing can be easily controlled.

  Moreover, what is necessary is just to set the press injection speed of the casing for pile construction, the drawing-out speed, and the rotational speed according to conditions, such as the condition of the ground and the diameter of the casing for pile construction. Furthermore, lateral runout or the like of the pile construction casing can be prevented by steadying.

  The auger motor is attached to a chain spanned between the upper and lower sprockets installed at the upper end and the lower end of the leader, respectively, and the chain is swung between the upper and lower sprockets by the drive motor. Can be moved up and down (not shown).

  ADVANTAGE OF THE INVENTION According to this invention, the cast-in-place concrete pile with a node provided with the joint part spirally continued in the axial direction of a pile main body on the outer periphery of a pile main body can be constructed very efficiently and easily.

  In addition to the joints spirally extending in the direction of the pile axis on the outer periphery of the pile body, the diameter of the pile body is larger and thicker than the pile body at any position in the axial direction of the pile body, such as the tip and middle of the pile body. A cast-in-place concrete pile with a knot can be constructed very efficiently and easily.

It is a side view which shows the casing for pile construction installed with the leader of a construction heavy machine. It is a perspective view which shows the steadying which supports the casing for pile construction, and its lower end part. It is a perspective view which shows a part of casing for pile construction. Fig. 4 (a) is a perspective view showing a lower end portion of a pile construction casing, Fig. 4 (b) is a perspective view showing a casing body and an enlarged blade, and Fig. 4 (c) is an enlarged blade. FIG. FIG. 5 (a) is a perspective view showing a cast-in-place cast-in-place concrete pile having enlarged joints at the tip and intermediate parts and a spiral continuous joint between them, and FIG. 5 (b) is the tip. It is a perspective view which shows the cast-in-place concrete pile with a node provided with the enlarged node part in the upper part, and the node part which followed the spiral shape in the upper part. 6 (a) to 6 (c) are explanatory diagrams showing a construction procedure of a cast-in-place concrete pile with a node. FIGS. 7A to 7C are explanatory views showing a construction procedure of a cast-in-place concrete pile with a node. 8 (a) to 8 (c) are explanatory views showing a construction procedure of a cast-in-place concrete pile with a node. It is a side view of the completed cast-in-place concrete pile with a node.

  1 to 4 show a pile construction casing used for construction of a cast-in-place cast-in-place concrete pile according to the present invention. A pile construction casing A has an enlarged blade 2 and a bottom at a lower end portion of a casing body 1 made of a steel pipe or the like. It is comprised by attaching the lid | cover 3 each.

  The expansion blade 2 is continuously formed on the outer periphery of the lower end portion of the casing body 1 in a spiral shape about one and a half to two turns in the tube axis direction of the casing body 1.

  The bottom cover 3 is formed to have substantially the same diameter as the outer diameter of the casing body 1, and the weight of concrete (described later) put into the casing body 1 by a method such as bonding to the lower end portion of the casing body 1 with an adhesive tape. It is attached so that it can easily fall off.

  For example, as shown in FIG. 4, a part of the expansion blade 2 (hereinafter referred to as “expansion blade 4”) is formed separately from the casing body 1 and is detachably attached to the lower end portion of the casing body 1. May be.

  The expansion blade 4 in this case is integrally formed from a cap portion 4a that can be mounted (covered) on the lower end portion of the casing body 1 and an expansion blade portion 4b that is formed in a spiral shape on the outer periphery of the cap portion 4a. Moreover, the bottom part of the cap part 4a comprises the bottom cover 4c, and the flat bar 4d is welded on the diameter direction of the cap part 4a on the bottom cover 4c.

  The enlarged blade 4 formed in this way is attached to the lower end of the casing body 1 and is detachably attached by fitting the flat bar 4d into a notch groove 1a formed in the lower end of the casing body 1. It has been.

  Accordingly, the expansion blade 4 rotates together with the casing body 1 and the expansion blade 2 and easily drops off due to the weight of concrete (described later) put into the casing body 1.

  In this way, by preparing a plurality of parts with different diameters of the enlarged blade part 4b and selecting and using them arbitrarily according to the conditions of the ground, etc., it is easy to form a cast-in-place concrete pile with a node part with the optimum diameter. can do.

  Reference numeral 5 denotes a construction heavy machine for constructing a pile using the pile construction casing A, and a leader 6 that vertically supports the pile construction casing A, and press-fitting into the ground while rotating the pile construction casing A. A yatco (connecting jig) 8 that transmits the rotational force of the auger motor 7 and the auger motor 7 to the pile construction casing A is provided, and a steady rest 9 that prevents lateral swing of the pile construction casing A is provided.

  In particular, the steady rest 9 is horizontally attached to the lower end portion of the leader 6 and rotatably holds the casing body 1 of the pile construction casing A to prevent the pile construction casing A from sideways.

  More specifically, the steady rest 9 is composed of a pair of gripping portions 9a, 9a formed in a semicircular shape, and the gripping portions 9a, 9a have a leader 6 side (fixed side) as a fulcrum and a distal end side (free end side). It opens and closes horizontally in the horizontal direction.

  Moreover, the fixing pin 10 which fixes the grip parts 9a and 9a in the closed state is attached to the front ends of the grip parts 9a and 9a in a detachable manner. The gripping portions 9a, 9a may be configured such that the leader 6 side (fixed side) opens and closes left and right with the tip side (free end side) as a fulcrum.

  In such a configuration, the upper end portion of the casing body 1 is connected to the auger motor 7 via the yatco 8, and the lower end portion of the casing body 1 is supported by the leader 6 via the contact stopper 9, and then the auger motor 7 is moved. When actuated (rotated) and lowered along the leader 6, the pile construction casing A rotates through the Yatco 8, and at the same time is guided by the steady rest 9, and gradually descends while rotating along the leader 6. Press-fitted into the ground.

  The auger motor 7 is moved up and down by a chain and a drive motor that rotates the chain between upper and lower sprockets installed at the upper end and the lower end in the leader 6 (not shown).

  Further, when the auger motor 7 is rotated in the reverse direction and raised along the leader 6, the pile construction casing A is gradually pulled out from the ground.

  At that time, by keeping the press-fitting (penetration) speed, the pull-out speed, and the rotation speed of the casing A for pile construction constant, the blade parts 2b, 2b of the enlarged blade part 2 are the same in the ground both during the press-fitting and during the penetration. Move up and down the position.

  This makes it possible to reliably form a columnar cavity (pile hole) that continues in the vertical direction in the ground and a spiral that continues spirally around the columnar cavity. These speeds can be easily controlled by adjusting the ascending / descending speed and rotation speed of the auger motor 7.

  Further, when the auger motor 7 is lifted along the rewinder 6 with the pile construction casing A in a non-rotating (non-rotating) state, the pile construction casing A rises vertically together with the auger motor 7.

  According to the above-described pile construction casing A, for example, a cast-in-place concrete pile with a node as illustrated in FIGS. 5A and 5B can be constructed very efficiently and easily.

  FIG. 5 (a) is provided with enlarged joints b and b formed at a predetermined thickness at the tip and intermediate parts of a pile body a continuous in a columnar shape, and spirally formed between the enlarged joints b and b. It shows a cast-in-place concrete pile with a knot provided with knots c formed continuously.

  Moreover, FIG.5 (b) was provided with the enlarged node part b formed in the predetermined | prescribed thickness in the front-end | tip part of the pile main body a, and the node part c formed continuously spirally above this. It shows a cast-in-place concrete pile with a knot.

  Next, a construction procedure for constructing a node cast-in-place concrete pile using the pile construction casing A of the present invention will be described (see FIGS. 6 to 9).

(1) First, a pile construction casing A is installed on the heavy construction machine 5 at a point where a cast-in-place cast-in-place concrete pile is to be constructed, and vertically laid. In this case, the pile construction casing A is vertically laid on the pile construction point along the leader 6 of the heavy construction machine 5. Then, the upper end of the casing body 1 is connected to the auger motor 7 via a yatco (connecting jig) 8 and the lower end is supported on the leader 6 via a steady rest 9 (see FIGS. 1 and 6 (a)). .

(2) Next, the auger motor 7 is actuated (rotated), and the pile construction casing A is rotated and press-fitted into the ground (see FIGS. 1 and 6 (b)). In addition, since the lower end part of the casing main body 1 is closed by the bottom lid 4, soil does not enter the casing main body 1 while the pile construction casing A is press-fitted into the ground.

(3) Next, when the pile construction casing A is press-fitted to a predetermined depth, the upper end of the casing body 1 is temporarily separated from the auger motor 7. Then, reinforcing bars d are arranged in the casing body 1 as necessary, and then concrete e is introduced (see FIGS. 1 and 6 (c)).

  The reinforcing bars d can be efficiently arranged by arranging bars assembled in a basket shape. In addition, it is desirable to use concrete or mortar having high fluidity for the concrete e because the filling property of the concrete is improved.

(4) Next, the upper end of the casing body 1 is reconnected to the auger motor 7 via the yatco 8, and the pile construction casing A is lifted up without rotating (rotating) the casing A for pile construction. A predetermined amount of the casing A is pulled out.

  When the pile construction casing A is pulled out by a predetermined amount, a predetermined amount of columnar cavity f is formed in the ground directly below the pile construction casing (see FIGS. 1 and 7 (a)).

  In addition, when the pile construction casing A is further pulled out while being reversely rotated by pulling out the pile construction casing A by an integral multiple of the installation interval L of the blade sections 2b, 2b of the expansion blade 2, the blade sections 2b, 2b passes through the spiral hollow portion f formed by the blade portions 2b and 2b of the expansion blade 2 when the pile construction casing A is press-fitted.

  Thereby, the cavity part f which continues in a spiral shape can be reliably formed around the columnar cavity part f. In addition, these things can be easily achieved by managing the press-fitting speed, extraction speed, and rotation speed of the casing A for pile construction.

  Moreover, at the same time as the pile construction casing A is pulled out, the bottom lid 3 attached to the lower end of the pile construction casing A falls off to the bottom of the cavity f by the weight of the concrete e in the casing body 1, It becomes a reinforcement for the tip of cast-in-place concrete piles with nodes (see Fig. 1 and Fig. 7 (b)).

  Further, the concrete e in the casing body 1 flows out from the lower end portion of the casing body 1 into the cavity portion f, is filled in the cavity portion f, and is solidified in the cavity portion f, so that the diameter is larger than that of the pile body a. In addition, a thick enlarged node (enlarged bottom) b is formed (see FIGS. 1 and 7C).

  In this case, the hollow portion f is formed with an inner diameter larger than the outer diameter of the casing body 1 by partially lifting up the soil in the upper portion of the enlarged blade 2 by the enlarged blade 2. Thereby, the expansion node part b formed in the cavity part f can be formed in the diameter larger than the outer diameter of the pile main body a.

(5) Next, the casing A for pile construction is gradually pulled out while rotating in the reverse direction. If it does so, the column-shaped cavity part f continuous in the axial direction of the casing main body 1 will be continuously formed in the downward direction directly under the casing main body 1 upward. In addition, a hollow portion f that is continuous in a spiral shape is formed continuously around the hollow portion f in a spiral shape.

  Then, the concrete e in the casing body 1 flows out from the lower end portion of the casing body 1 into these cavities f, fills the cavities f, and solidifies integrally in the cavities f. Thereby, the pile main body a and the spiral-shaped node part c are continuously formed integrally (refer FIG.7 (c)).

(6) Next, the auger motor 7 is stopped to temporarily stop the rotation of the pile construction casing A, and the pile construction casing A is rotated in a non-rotation state (not rotated) in the manner described in the above (4). Pull out. Then, a cavity part f is formed in the ground directly under the pile construction casing (see FIGS. 1 and 8 (a)).

  At the same time, the concrete e in the casing body 1 flows out from the lower end portion of the casing body 1 into the cavity portion f, fills the cavity portion f, and solidifies in the cavity portion f, whereby the node portion b becomes a spiral-shaped node. It is formed continuously with the portion c (see FIGS. 1 and 8B). As a result, a node portion b having a diameter larger than that of the pile body a and thicker than the spiral node portion c is formed at an intermediate portion of the pile body a.

  In the same manner, the total length of the cast-in-place cast-in-place concrete can be efficiently and easily performed by alternately and continuously performing the steps (5) and (6) (FIG. 8 (c), (See FIG. 9).

  The present invention provides a highly efficient and cast-in-place cast-in-place concrete pile with a spiral continuous spiral in the axial direction of the pile body and an enlarged joint at any position in the pile axial direction on the outer periphery of the columnar pile body. Easy to install.

A Pile construction casing 1 Casing body 2 Enlargement blade 3 Bottom cover 4 Enlargement blade 5 Construction heavy machinery 6 Leader 7 Auger motor 8 Yatco (connecting jig)
9 steady rest 9a gripping part 10 fixing pin

Claims (1)

A pile construction casing having an enlarged blade integrally attached to the lower end portion of the casing body and a bottom cover detachably attached is press-fitted into the ground while rotating , and concrete is put into the casing body of the pile construction casing. And then gradually pulling out the pile construction casing while rotating it in the reverse direction, and simultaneously filling the columnar cavity and the spiral cavity formed by the casing body and the expanding blade with the concrete in the casing body. In the construction method of a cast-in-place cast-in-place concrete pile that integrally forms a pillar-shaped pile body and a spiral-shaped joint portion, the casing for pile construction is pulled out by a predetermined amount without rotation, and the casing body and the expansion blade are provided below the casing body. The cavity is formed by the casing book at the same time in the cavity Construction method of in-place concrete piles characterized by integrally formed enlarged knuckles on the outer periphery of the pile body by filling concrete in the.

Images