JP2010270511A - Pile head cap, and pile driving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pile head cap and a pile driving method allowing continuous driving up to a depth of a ground level or deeper, without replacing an adaptor or the like of a heavy machine from start of drilling to finish thereof, and used for drilling a recycle plastic pile or the like for reinforcing a building foundation of a dwelling house or the like. <P>SOLUTION: This pile head cap 1 includes a shaft part 3, and a cylindrical part 4 extended downwards from a lower end of the shaft part 3 to be engaged with an outer circumference of a head part of a pile 2. Level gauges 8, 9 are embedded into the shaft part 3. An upper end face 3a of the shaft part 3 is formed into a convex-curved face, and a pile core display mark 7 is marked on the upper end face. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pile used for reinforcing a foundation of a building such as a house, in particular, a pile head cap serving as a jig for placing a recycled plastic pile, and a pile placing method using the pile head cap.

  As a foundation reinforcement method when the ground strength is insufficient, there is a method of driving a pile to the supporting ground. For example, steel pipe piles are used as the piles, and a large number of such piles are arranged, for example, arranged at a constant pitch in the longitudinal direction under the cloth foundation.

  For example, the method shown in FIG. In the method shown in the figure, a cap-like adapter 25 for preventing the inclination of the pile 2 is attached to the lifting head 24 of the heavy machine 21, and the lifting head 24 is lowered to allow the pile 2 to penetrate deeper than the ground level GL. Since the foundation is constructed over the plurality of piles 2 above the piles 2, the piles 2 are placed slightly deeper (for example, about 300 mm) deeper than the ground level GL as shown in FIG. After the placement is completed, the center misalignment and inclination of the pile 2 are confirmed.

Japanese Patent No. 2939157 JP 2006-274639 A JP 2005-155285 A

In the conventional pile driving method of FIG. 7 (A), if the cap-shaped adapter 25 hits the ground surface as it is driven directly on the ground, it becomes an obstacle to penetration, or because the lower stroke end of the lifting head 24, It cannot be placed deeper than the ground level GL as in (B). Therefore, after placing the ground level to about GL, it is necessary to replace the adapter 25 with a non-cap type that does not interfere with the ground surface, or to dig a hole or a groove in the ground G in advance, which takes time. . In addition, if the non-cap type adapter is used from the beginning of placing, the pile 2 is inclined.
Moreover, since it is necessary to drive the pile 2 in the range of allowable inclination, it is necessary to confirm the inclination of the pile 2 in the middle of driving. Conventionally, it was necessary to interrupt the construction and apply a leveling device every time the inclination was confirmed, and this also took time. In addition, the measurement of misalignment, inclination, etc. after the placement is completed is performed with the upper end of the pile 2 positioned about 300 mm below the ground level GL. Difficult to measure misalignment and inclination.

  In addition, although the steel pipe is used for the pile 2 in the conventional ground reinforcement method, it is calculated | required to use a recycled plastic for the effective use of resources also in the field of construction. Therefore, the present inventors tried to use recycled plastic for the pile 2. In the case of recycled plastic piles, there is a risk that the pile head will be damaged when pushing down with heavy machinery. Therefore, prevention of damage to the pile head is also desired.

An object of the present invention is to provide a pile head cap and a pile driving method that can be driven continuously to a depth below the ground level without exchanging adapters or the like of heavy machinery from the start of driving to completion.
Another object of the present invention is to facilitate the management of the inclination during pile driving.
Still another object of the present invention is to facilitate the measurement of the misalignment of the pile head after completion of driving.

The pile head cap according to the present invention is a pile head cap that is a jig that is put on the top of the pile and is given a pressing force by a heavy machine on the upper surface, and serves as a jig that allows the pile to penetrate into the ground. A shaft portion that is in a standing posture in a state of being covered with, and a cylindrical portion that extends downward from the lower end of the shaft portion and fits to the outer periphery of the head of the pile, and the pile includes the pile portion. The pile head upper surface engaging surface which hits the upper surface of the head.
According to the pile head cap of this configuration, the pile head holding adapter attached to the lifting head of the heavy machinery can be driven by being fitted to the shaft portion of the pile head cap. In this case, since there is a shaft part above the cylindrical part that covers the pile head, even if the descent of the pile head holding adapter is stopped at the ground surface level, the pile is grounded by the length of the shaft part. Can be driven deeper. Therefore, it is possible to continuously place the ground up to the ground level without exchanging the adapter from the start to the end of the placement.

A leveler may be embedded in the shaft portion of the pile head cap. For example, a leveler may be embedded in the upper part of the upper end surface or the side surface of the shaft part.
In this way, when the leveling device is embedded in the pile head cap, the inclination of the pile can be measured by looking at the embedded leveling device without applying another leveling device to the pile. Therefore, it is not necessary to interrupt the construction for confirming the inclination, and the inclination can be confirmed while continuing the placement. Since the level is embedded, it does not hinder pile driving. When the leveling device is located on the top surface of the pile head cap, the leveling device can be seen and the inclination can be measured even when the installation is completed deeper than the ground level.

In this pile head cap, the upper end surface of the shaft portion may be a convex curved surface from which the shaft center portion projects, and a pile core display mark for displaying the pile shaft center may be provided on the upper end surface of the shaft portion.
In this way, when the pile core display mark is applied to the upper end surface of the pile head cap, after completing the pile placement, for example, when imaging the upper surface of the pile and trying to measure the misalignment of the pile by image processing The pile core position can be confirmed from the image of the pile core display mark. Therefore, it becomes easy to measure misalignment. In addition, since the pile uses a standard product, there is no pile core display mark, and it takes time and effort to apply the pile core display mark to each pile. In addition, when the upper end surface of the shaft part is a convex curved surface from which the shaft center part protrudes, when vibration is applied by heavy equipment, the pile head cap is not biased against the pile head holding adapter of the heavy equipment. It is difficult to cause damage due to local contact.

The pile driving method of the present invention is a pile driving method in which a pile head cap is put on the head of the pile, and a pressing force is applied to the upper surface of the pile head cap by a heavy machine to penetrate the pile into the ground. A pile head cap having any one of the above configurations of the present invention is used for the pile head cap.
According to this method, the above-described effects described with respect to the pile head cap of the present invention, for example, can be driven continuously to the ground level or below without exchanging adapters or the like of heavy machinery from the start to the end of driving. The effect is obtained.

The pile head cap according to the present invention is a pile head cap that is a jig that is put on the top of the pile and is given a pressing force by a heavy machine on the upper surface, and serves as a jig that allows the pile to penetrate into the ground. A shaft portion that is in a standing posture in a state of being covered with, and a cylindrical portion that extends downward from the lower end of the shaft portion and fits to the outer periphery of the head of the pile, and the pile includes the pile portion. Since it has a pile head upper surface engaging surface which hits the upper surface of the head, it can be driven continuously from the start to the end of the operation without exchanging adapters or the like of heavy machinery.
When a leveling device is embedded in the shaft portion, it becomes easy to manage the inclination during pile driving.
When the upper end surface of the shaft portion is a convex curved surface projecting from the shaft center portion, and the pile core display mark indicating the pile shaft center is applied to the upper end surface of the shaft portion, The misalignment can be easily measured, and it is difficult to damage even if vibration is applied during placement.
The pile driving method of the present invention is a pile driving method in which a pile head cap is put on the head of the pile, and a pressing force is applied to the upper surface of the pile head cap by a heavy machine to penetrate the pile into the ground. Since the pile head cap is a method using the pile head cap of any one of the above-described configurations of the present invention, it is continuously driven from the start to the end of the installation to the depth below the ground level without exchanging adapters of heavy machinery. be able to.

(A), (B), (C) is the top view of this pile head cap, the partial fracture front view, and the partial fracture front view of a pile fitting state, respectively. It is explanatory drawing of the pile driving process using the same pile head cap. It is an enlarged view of the upper surface of the pile head cap. It is explanatory drawing of the method of measuring misalignment after completion of placement by the pile placement method. It is explanatory drawing of the example of an image in the concentricity measuring method. It is explanatory drawing of the tolerance calculation corresponding to inclination in the concentricity measuring method. It is explanatory drawing of a prior art example.

  An embodiment of the present invention will be described with reference to FIGS. 1A to 1C are a top view, a partially broken front view, and a partially broken front view of a pile fitting state of the pile head cap, respectively. The pile head cap 1 is used for placing the pile 2. The pile 2 serves as a pile in a pile foundation of a building such as a house or a piled raft foundation which is a composite foundation of a direct foundation such as a cloth foundation and a pile, and is made of, for example, recycled plastic. The pile 2 has dimensions of, for example, a diameter of 60 to 100 mm and a length of 900 to 2,400 mm. The pile 2 may be made of steel pipe or other material.

The pile head cap 1 includes a shaft portion 3 and a cylindrical portion 4 that extends downward from the lower end of the shaft portion 3 and fits to the outer periphery of the head portion of the pile 2. The shaft portion 3 and the cylindrical portion 4 are made of a steel material that is integral with each other. The cylindrical portion 4 has a stepped cylindrical shape having a plurality of pile-diameter fitting portions 4a, 4b, and 4c having different inner diameters so that the diameter gradually decreases toward the upper side. The inner diameters of the fitting portions 4a, 4b, and 4c corresponding to the respective pile diameters are dimensions to be fitted to the piles 2 (2 _A , 2 _B , 2 _C ) having outer diameters of φ100, φ80, and φ60 (unit mm), respectively. . Pile diameter corresponding fitting portions 4a, 4b, the stepped surface between 4c, and the bottom surface of the minimum diameter of the pile diameter corresponding fitting portion 4c, respectively, pile 2 of the corresponding diameter (2 _A, 2 _B, 2 _C) It is set as the pile head upper surface engaging surface 5a, 5b, 5c which hits the upper surface of a head.

  The outer peripheral surface of the pile head cap 1 extends over the shaft portion 3 and the cylindrical portion 4 and is a cylindrical surface without a step. The outer diameter of the shaft portion 3 and the cylindrical portion 4 is equal to the outer diameter of the pile 2 having the largest diameter among the piles 2 to be used by the thickness that ensures the strength of the fitting portion 4a corresponding to the lowermost pile diameter. It is made larger than the diameter. The length of the shaft portion 3 is, for example, about 300 mm.

  The entire inner surface of the cylindrical portion 4 is covered with a cushioning material 6 made of a rubber-like elastic body. A rubber material such as hard rubber or a resin material is used for the rubber-like elastic body serving as the buffer material 6. The cushioning material 6 may be coated on the inner surface of the cylindrical portion 4, or may be molded, fitted into the inner surface of the cylindrical portion 4, and bonded. These rubber materials and resin materials are assumed to have a lower surface hardness than the pile 2. When the buffer material 6 is provided, the inner diameter of each of the pile diameter-corresponding fitting portions 4 a, 4 b, and 4 c is an inner diameter in which each corresponding pile 2 is fitted via the buffer material 6. In FIG. 1C, the buffer material 6 is not shown.

  The upper end surface 3a of the shaft portion 3 is a convex curved surface from which the shaft center portion protrudes, and the protrusion height is a fraction to several tens of minutes with respect to a chord in a gentle spherical shape, for example, an arc-shaped cross section of the spherical surface. It has a spherical shape of about one degree. A pile core display mark 7 for displaying the pile axis O is provided on the upper end surface 3 a of the shaft portion 3. In the illustrated example, the pile core display mark 7 is divided into four sections by a cross-shaped mark composed of two orthogonal straight lines 7a and 7b passing through the axis of the upper end surface 3a of the shaft portion 3, and the two straight lines. It consists of colored portions 7c and 7d that are colored so that each of the divided two divided sections has the same color. The colors of the coloring portions 7c and 7d may be chromatic colors or achromatic colors. The straight lines 7a and 7b may be lines provided separately from the colored portions 7c and 7d, or may be lines that appear as edges of the colored portions 7c and 7d.

  Level portions 8 and 9 are embedded in the shaft portion 3 at the upper end surface 3a and the upper portion of the outer peripheral surface. The leveling device 8 on the upper end surface 3a is positioned away from the axis O and not on the straight lines 7a and 7b. These levelers 8 and 9 are liquids such as water sealed so that one bubble 8a and 9a is generated in a sealed chamber in which a surface exposed to the outer surface of the pile head cap 1 is a transparent window. The transparent window of the leveling device 9 on the outer peripheral surface is divided into a plurality of rows aligned in the circumferential direction. The transparent window is made of a transparent resin material or glass. The inner surface of the transparent window has a spherical shape in the level device 8 of the upper end surface 3a, and the bubble 8a moves to a position corresponding to the inclination by the inclination of the shaft portion 3. The inner surface of the transparent window of the leveling device 9 on the outer peripheral surface has a curvature along the shaft portion 3, and the bubbles 9 a move according to the inclination of the shaft portion 3.

Next, a pile driving method using the pile head cap 1 will be described. As shown in FIG. 1C, the pile head cap 1 is put on the head of the pile 2. At this time, according to the outer diameter of the pile 2, it is made to fit in the corresponding pile diameter corresponding | compatible fitting part 4a, 4b, 4c. In addition, since the pile diameter corresponding | compatible fitting parts 4a, 4b, and 4c are provided in order with the level | step difference, if the cylindrical part 4 of the pile head cap 1 is covered as much as possible in the pile 2, the pile corresponding to a pile diameter will be shown. It fits into the diameter corresponding fitting parts 4a, 4b, 4c. FIG. 1 (C) the three types of the pile 2 _A to 2 _C of diameter, shows a state in which the pile 2 _B is fitted in the intermediate diameter, fitted in the middle of the pile diameter corresponding fitting portion 4b Yes. As shown by broken lines in the figure, the pile 2 _A maximum diameter is fitted to the lower part of the pile diameter corresponding fitting portions 4a, pile 2 _C of minimum diameter is fitted to the top of the pile diameter corresponding fitting portion 4c To do.

  In this way, the pile head cap 1 is put on the pile 2, and the pile 2 is penetrated into the ground G by the heavy machine 21 which is a pile driving machine as shown in FIG. The heavy machine 21 is configured such that a propulsion 23 is provided on a travelable vehicle body 22 having wheels, and an elevating head 24 that moves up and down along the prop 23 is provided. A lift driving source (not shown) such as a hydraulic cylinder for moving the lifting head 24 up and down is provided on the vehicle body 22 or the column 23. The elevating head 24 may have a vibration device (not shown). A cap-shaped adapter 25 is attached to the lifting head 24. The cap-shaped adapter 25 is fitted to the upper end of the pile head cap 1 and the elevating head 24 is lowered, whereby the pile 2 is pushed down through the pile head cap 1 and is inserted into the ground G by press fitting.

  FIG. 2 (A) shows a state in which the pile 2 is being placed, and the lower end of the pile 2 is at a height at which it hits the surface of the ground G at the start of placement. When the placement is performed as described above and substantially the entire pile head cap 1 penetrates the ground G as shown in FIG. 2 (B), the pile driving work is completed. The slope of the pile 2 is confirmed by looking at the leveling device 9 on the outer peripheral surface of the pile head cap 1 during this pile driving operation. When the allowable inclination is exceeded, the pile 2 is pulled out and redoing is performed.

According to this construction method, since the pile head cap 1 having the shaft portion 3 is used, as shown in FIG. 2B, the upper end of the pile 2 has a predetermined depth H (for example, 300 mm) below the ground level GL. Until it reaches For this reason, it is possible to drive continuously from the ground level to the ground level GL without replacement of the adapter 25 of the heavy machine 22 from the start to the end. Pile cap 1, a plurality of different pile diameter corresponding fitting portion 4a of the inner diameter, 4b, because it has 4c, it is used in common to the pile 2 _A, 2 _B, 2 _C of different outer diameter it can.

  Since the upper end surface 3a of the shaft portion of the pile head cap 1 is a gently spherical convex curved surface, even if vibration is applied to the lifting head 24 of the heavy machinery 22, the pile head cap 1 is hardly damaged. Moreover, since the shock absorbing material 6 is provided in the inner surface of the cylindrical part 4 of the pile head cap 1, even if it adds a vibration, the head of the pile 2 is hard to be damaged. In addition, although the steel pipe is used for the pile 2 in the conventional ground reinforcement method, it is calculated | required to use a recycled plastic for the effective use of resources also in the field of construction. Therefore, the present inventors tried to use recycled plastic for the pile 2. In the case of the recycled plastic pile 2, the pile head may be damaged when a 21-pushing force is applied by a heavy machine. In such recycled plastic 2 as well, scratching of the pile head is prevented by providing the cushioning material 6.

  Moreover, since this pile head cap 1 is provided with the level device 9 in the outer periphery, the inclination of the pile 2 can be confirmed during placement. This eliminates the need for a dedicated leveler and improves workability. Although the leveling device 9 on the outer peripheral surface is buried under the ground G in the state where the pile 2 is completely placed, the inclination can be confirmed even in the state where the pile 2 is completed by looking at the leveling device 8 on the upper end surface 3a. The level 8 can grasp the approximate inclination degree by the position of the bubble 8a. Since the pile core display mark 7 is provided on the upper end surface 3a of the pile head cap 1, the misalignment from the target position of the pile 2 can be easily performed.

  An example of a method for measuring the misalignment of the pile 2 will be described with reference to FIGS. When the pile 2 is driven below the fabric foundation or the like, as shown in FIG. 4, a plurality of piles 2 are driven side by side along the core of the foundation. The pile head cap 1 is left on the pile 2 until the pile driving of all the piles 2 for one building is completed even after the pile driving is completed. The pile head caps 1 of the plurality of piles 2 are simultaneously imaged by the camera 31, and are subjected to image processing by the misalignment confirmation means 32 configured by a personal computer, a program, and the like to confirm misalignment. After this confirmation, the pile head cap 1 of each pile 2 is removed and used for reuse.

  FIG. 5 shows an example of the image. Since the pile core display mark 7 is provided on the upper surface of the pile head cap 1, image processing indicating the pile core can be easily performed. The misalignment can be confirmed by comparing the difference between the center of the display mark 7 in the image and the pile driving target line or the target position.

However, as shown in FIG. 6, when the pile 2 is inclined, an error from the actual misalignment amount occurs depending on the length of the pile head cap 1.
For example, if the inclination is 1/50 and the pile head depth H ′ generated in the pile head cap 1 is 300 mm below the ground level GL, the allowable margin B depending on the length of the pile head cap 1 is about 6 mm. It becomes. Therefore, if the allowable misalignment value A is 100 mm, the allowable misalignment distance A ′ to be measured is set to about 94 mm obtained by subtracting the margin length of 6 mm.

DESCRIPTION OF SYMBOLS 1 ... Pile head cap 2 ... Pile 3 ... Shaft part 4 ... Cylindrical part 4a, 4b, 4c ... Pile diameter corresponding fitting part 5a, 5b, 5c ... Pile head upper surface engagement surface 6 ... Buffer material 7 ... Pile core display Marks 8, 9 ... Level 21 ... Heavy machine 24 ... Lifting head 25 ... Cap-shaped adapter

Claims (4)

It is a pile head cap that is a jig that penetrates the pile into the ground by covering the head of the pile and applying a pressing force on the upper surface by a heavy machine,
A shaft portion that is in a standing posture in a state where the pile head cap is put on the pile, and a cylindrical portion that extends downward from the lower end of the shaft portion and fits to the outer periphery of the head of the pile. The pile head cap which has a pile head upper surface engagement surface which hits the upper surface of the head of the said pile in a shape part.   The pile head cap according to claim 1, wherein a leveling device is embedded in the shaft portion.   The pile head cap according to claim 1 or 2, wherein the upper end surface of the shaft portion is a convex curved surface from which an axial center portion projects, and a pile core display mark for displaying a pile shaft center is provided on the upper end surface of the shaft portion. . A pile driving method in which a pile head cap is put on the head of the pile, and the upper surface of the pile head cap is pushed down by a heavy machine to penetrate the pile into the ground,
The pile driving method characterized by using the pile head cap of any one of Claim 1 thru | or 3 for the said pile head cap.

Images