JPS6146611B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for adding and erecting PC piles (hollow circular ready-made concrete piles with prestress introduced), and its purpose is to arrange upper and lower piles concentrically. This is a new method that makes it easy to add accurately and ensure the verticality of the added top and bottom piles, which is extremely effective in preventing so-called high piles, and also enables efficient use of heavy machinery for pile erection. and propose a useful method.

Conventionally, in the cement milk injection method, PC
When adding piles and erecting them as long piles, as shown in Figure 1, the PC pile lower pile a is hung with a wire b, and then moved into the vertical hole d to the desired depth using a traveling heavy machine c. While it was inserted, another heavy machine was used to remove the PC.
Hang the upper pile e with the wire f and attach the PC pile lower pile a
After suspending the PC pile above and welding the end plates of the upper and lower piles e and a, remove the wire b of the lower PC pile a and lower the upper and lower piles e and a into the vertical hole d. was.

However, as shown in the figure, when the PC pile lower pile a is pulled laterally with the wire b and held at the desired depth, the PC pile lower pile a is inclined with respect to the vertical line. It was difficult to connect the PC pile top piles e in a concentric manner, and in some cases, they were bent in a dogleg shape and connected, which caused the so-called high-stacking phenomenon. In addition, even if the upper and lower piles e and a can be connected concentrically and accurately, when the wire f is wrapped around them and suspended, an eccentric load will be applied, so the entire pile will be slightly inclined with respect to the vertical line. In some cases, this caused the prices to remain high.

Moreover, in the above conventional method, the upper and lower piles e, a
Separate heavy machinery was required to suspend the pipes, which resulted in poor efficiency in the use of heavy machinery and increased construction costs.

The method of the present invention eliminates these conventional drawbacks, and after completing the excavation of the vertical hole, a frame is installed on the ground around the vertical hole, and the PC pile lower pile is suspended and inserted into the vertical hole to the desired depth. At the same time, the area near the pile head is supported on the frame via a ring-shaped metal fitting placed around the outer periphery of the area near the pile head, so as to be rotatable around mutually orthogonal axes in approximately the same horizontal plane, and the PC is loaded by its own weight.
Ensure the verticality of the lower pile, then install the upper PC pile,
The lower end of the PC pile is suspended in a vertical position via a bolt screwed into a screw hole formed in the upper end plate and a string-like body secured to the head of the bolt. By welding the plate and the upper end plate of the PC pile lower pile, the PC
The upper pile and the lower PC pile are connected concentrically, and then the supported state of the lower PC pile by the mount is released, and the upper PC pile and the lower PC pile are connected via the bolt and string-like body. The feature is that the lower pile is inserted into the vertical hole to the desired depth.

Embodiments of the present invention will be described below based on the drawings.

First, the devices used in the method for adding and erecting PC piles of the present invention will be explained.

Figures 2 and 3 show a holding device that vertically holds the PC pile lower pile A. Reference numeral 1 denotes a frame comprising an upper frame 1a, a lower frame 1b, and legs 1c. Recesses 1d for positioning are formed on the upper edges of the two opposing sides. 2 is configured so that it can be divided into two,
Specifically, by removing bolts and nuts 3,
It is a ring-shaped hardware consisting of two semicircular parts that can swing open and close around a hinge 4, and a pair of shaft bodies 5 protrude concentrically from each other at opposite positions on the outer surface. has been done. These shaft bodies 5...
... can be inserted into and removed from the recess 1d, and can rotate about its axis when fitted into the recess 1d. In the illustrated embodiment, a male thread is formed on the shaft body 5, and the ring-shaped hardware 2 is attached to the frame 1 by applying the nut 6, which is screwed to the male thread, to the outer surface of the upper frame 1a.
The shaft body 5 is configured to be positioned in the axial direction. Further, on the upper edge of the ring-shaped hardware 2, positioning recesses 7 are formed at positions that are 90 degrees out of phase with the shafts 5 in the circumferential direction of the ring-shaped hardware 2. On the other hand, in the vicinity of the pile head of the PC pile lower pile A, female screw bodies 8 perpendicular to the pile core are concentrically buried in advance at two positions in the diametrical direction. And these female screw bodies 8...
A pair of screw shafts 9 screwed into the recess 7...
It is constructed so that it can be freely inserted into and removed from and rotatably inserted into. 9a is...a ring-shaped rotation operation part, and 10... is applied to the outer surface of the ring-shaped hardware 2 to position the ring-shaped hardware 2 in the screw shaft 9...axial direction with respect to the PC pile lower pile A. It's Natsuto. 11 is an end plate on the upper end side of the PC pile lower pile A, and 12 is a screw hole used to apply tension to the PC steel material buried in the pile (not shown) during the manufacture of the PC pile.

Figure 4 shows the hanging jig for PC pile top pile B. This jig has a screw hole formed in the upper end plate 13 (similar to the screw hole 12 described above).
It was used to apply tension to prestressing steel. ) 14... and a string-like body 16, such as a wire with a hook or a chain with a hook, which is engaged with the ring-shaped head 15a of the bolt 15... , when the string-like body 16 is suspended by the hanging hook 17 of heavy machinery,
The PC pile top pile B is configured so that it assumes a vertical posture due to its own weight.

Next, the PC using the above holding device and hanging jig
The method of adding and erecting piles will be explained based on Fig. 5 A to D.

As shown in FIG. 5A, after the excavation of the vertical hole 18 is completed, the pedestal 1 is installed on the ground around the vertical hole 18.
Next, wind the wire 19 around the PC pile lower pile A,
Suspend it with heavy machinery and insert the PC pile lower pile A into the vertical hole 18. In this case, as shown in the figure, by screwing the screw shaft 9 into the female threaded body 8 of the PC pile lower pile A, the screw shaft 9 can be connected to the wire 19.
Can be used as a non-slip member. After inserting the PC pile lower pile A into the vertical hole 18, the ring-shaped hardware 2
It may be placed around the lower pile A and pivotally supported by the pedestal 1, or if it does not get in the way of the wire 19, it may be pivotally supported by the pedestal 1 in advance as shown.

When the lower PC pile A is inserted to the desired depth, the screw shaft 9 is fitted into the recess 7 of the ring-shaped hardware 2, as shown in FIG. In this state, the vicinity of the pile head is attached to the ring-shaped hardware 2 by the screw shaft 9.
Since the ring-shaped hardware 2 is rotatably supported around the axis of the shaft 5 on the frame 1, the lower end of the PC pile lower pile A The sides can swing freely in any direction, and due to their own weight
The verticality of the PC pile lower pile A is ensured. Note that cement milk or soil cement (a mixture of cement milk and excavated soil) exists in the vertical hole 18, and buoyancy acts on the PC pile lower pile A, so that the shaft body 5..., the screw shaft 9... Even if the diameter of ... is not set too large, there is no risk of it breaking due to the weight of PC pile lower pile A.

Next, as shown in FIG. The PC pile lower pile A is welded to the upper end side end plate 11, and the upper and lower piles B and A are concentrically connected. In this case, the PC pile lower pile A is held in a vertical position in advance, and the PC pile upper pile B also uses the bolts 15... and the string-like body 16. It does not tilt due to eccentric loads, and maintains a vertical posture due to its own weight. Therefore, the upper and lower piles B and A can be easily connected concentrically. In addition, place the PC pile lower pile A on the frame 1.
Therefore, the heavy machinery used to suspend the lower pile A can be used to suspend the upper PC pile B, and no heavy machinery is required.

After that, as shown in Fig. 5 D, the supporting state of the PC pile lower pile A by the frame 1 is released, and the PC pile upper pile B and the PC pile lower pile A are maintained in a vertical position by their own weight, and the vertical hole is 18 to the desired depth.

6 and 7 show another embodiment, in which the screw shaft 9
... is formed in the ring-shaped metal fitting 2 (in the illustrated embodiment, the nut 2 welded to the ring-shaped metal fitting 2
It is formed by a. ) is provided in a screwed state, and at the inner end of the screw shaft 9..., an arc-shaped backing plate part 20... that makes surface contact with the outer peripheral surface of the PC pile lower pile A...
It is characterized in that the PC pile lower pile A is held between the backing plate part 20 and the backing plate part 20 by being fitted so as to be relatively rotatable. According to this embodiment, there is no need to bury the female screw body 8 in the vicinity of the pile head of the lower PC pile A.

As is clear from the above examples, according to the method of the present invention, the vicinity of the pile cap of the PC pile lower pile is placed on the frame,
The PC pile is supported rotatably around mutually orthogonal axes in approximately the same horizontal plane via a ring-shaped hardware, and the verticality of the PC pile lower pile is ensured by its own weight, while the PC pile upper pile is supported at its upper end. Suspended in a vertical position via a bolt screwed into a screw hole formed in the end plate and a string-like body secured to the head of the bolt,
Since the two are connected by welding, the upper and lower piles can be easily and accurately connected concentrically.
Since the entire upper and lower piles can be lowered in a vertical position, this is extremely effective in preventing the piles from staying too high.

In addition, since the PC pile lower pile is supported on the frame, the heavy machinery used to hang the lower PC pile can be used to hang the PC pile upper pile, and there is no need for heavy machinery to accompany it, making the use of heavy machinery more efficient. construction costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional example. Figure 2 and subsequent figures show embodiments of the present invention, where Figure 2 is a longitudinal sectional front view of the main part, Figure 3 is a plan view of the main part, Figure 4 is a partially cutaway front view of the main part, and Figure 5. A, B, C, and D are explanatory diagrams of the steps, and FIGS. 6 and 7 are a longitudinal sectional front view and a partially cutaway plan view of the main part showing another embodiment. A... PC pile lower pile, B... PC pile upper pile, 1... Frame, 2... Ring-shaped hardware, 13... End plate, 14... Screw hole, 15... Bolt, 15a...
...head, 16... string-like body.

Claims (1)

[Claims] 1 After completing the excavation of the vertical hole, install a frame on the ground around the vertical hole, suspend the PC pile lower pile and insert it into the vertical hole to the desired depth, and place the area near the pile cap on the frame. The verticality of the PC pile lower pile is ensured by its own weight by placing it around the PC pile or supporting it rotatably around mutually orthogonal axes in approximately the same horizontal plane through a ring-shaped hardware, and then A PC pile-top pile is suspended in a vertical position via a bolt screwed into a screw hole formed in the upper end plate and a string-like body secured to the head of the bolt. By welding the lower end plate of the upper pile and the upper end plate of the PC pile lower pile, the PC pile upper pile and the PC pile lower pile are connected concentrically, and then the PC pile is lowered by the mount. A method for adding and erecting a PC pile, which comprises loosening the supporting state of the pile and inserting a PC pile upper pile and a PC pile lower pile into a vertical hole to a desired depth via the bolt and string-like body.