JPS6026887B2 - Construction method and equipment for cast-in-place knot piles - Google Patents

Description

[Detailed description of the invention] The present invention relates to a construction method for cast-in-place piles and its counterfeiting.

Conventionally, the method of constructing foundation piles in the ground silently and without vibration involves digging a hole in the ground with a screw auger and injecting filler such as mortar or cement milk into the hole as appropriate.
The so-called flower IP method, MIP, in which a foundation pile is created by inserting core materials such as shaped steel, reinforcing bars, and ready-made piles into the unhardened pile-shaped body of the mortar.
The construction method is already known. Also known is a friction construction method using knotted piles, in which several knots are attached to the pillar surface of the pile in order to provide stronger frictional support with the surrounding area. A silent and vibrationless cast-in-place pile construction method is being developed in which a pile is inserted into a mortar column instead of the core material.

However, because the shape of the pile pillars created at the palace using these construction methods is cylindrical, the bearing capacity due to friction around the pile is extremely low, and the bearing capacity of the pile tips alone cannot provide strong and stable support. Even though pre-fabricated piles are used at all costs due to lack of hair, they have the drawback that they are difficult to demonstrate their original effect as foundation piles, and even when pre-fabricated piles with knots are used, the function of the knots is diminished. The desired effect of the joints could not be obtained at all. The present invention is intended to fundamentally solve this drawback, and uses a screw auger that is provided with enlarged blades that extend between the screw blades by hydraulic pressure to create an arbitrary space between the top and bottom of the peripheral wall. A column of mortar or cement milk having multiple joints is formed in the ground, and a pile-shaped reinforcing bar is inserted into the unhardened mortar column to create a cast-in-place joint pile. The purpose of this is to make the supporting force due to oka friction extremely stable and strong, and to carry out the construction quickly and reliably.

Hereinafter, an embodiment of the construction method of cast-in-place knot piles and the configuration of the device according to the present invention will be explained with reference to the drawings. It has an auger head 3 at its lower end, and its upper end is connected to a drive motor M via a connecting flange 4.

The present invention utilizes such a screw auger, and an enlarged blade 6 is formed in the spiral groove 5 of the screw blade 2 in a curved direction toward Wakkanai along the outer periphery of the screw blade 2. The opening/closing operation of the enlarged blade 6 is carried out by a swivel mechanism 8 installed on the drive shaft below the drive motor M, which is attached to the outer or inner wall of the auger shaft 1, as shown in the first figure. This is carried out by the reciprocating action of a piston punch 11 of a hydraulic cylinder 10 which is connected to an oil pipe 9, and has a blade size that is a tenth larger than the diameter of the hole A dug by the screw auger S during expansion. A closed blade stripe diameter is formed in the spiral groove 5 during rotary excavation,
When excavating the nodal hole B, the piston village 11 is actuated, the enlarged blade 6 is placed over the side, and the circumferential wall of the excavated hole A by the auger is further excavated to form the nodal hole B with a larger diameter.

The enlarging blade 6 is normally supported so that a gap is created between the inner surface of the enlarging blade 6 and the auger shaft 1 through which soil can pass during excavation. The diameter of the enlarged blade 6 can be adjusted to any desired diameter very easily by changing the supporting position of the pin shaft 7 or the blade size of the enlarged blade 6. Reference numeral 12 denotes a pouring hole for mortar, cement milk, etc. that can be conducted inside the auger shaft 1, and is connected to a nozzle port 13 that is connected to the lower end of the auger head 3, and the auger shaft 1 supports the enlarged blade 6. If the spout 14 is also provided in the auger tip, mortar and cement milk can be reliably injected and filled into the nodal hole B as well as the tip of the auger.

In the drawing, reference numerals 15 and 16 are stoppers for regulating the maximum extension or retraction, and 17 is a hydraulic pump.

Next, to explain the construction method of cast-in-place knot piles using the above-mentioned device, the screw auger S having the enlarged blade 6 is rotated by the drive motor M to drill a pile hole A in the ground where the desired foundation pile is to be constructed. When the excavation reaches a predetermined depth, the rotation is temporarily stopped, and the hydraulic cylinder 10
is actuated to extend the piston village 11 and rotate the enlarged blade 6 to open the widening portion, thereby drilling a larger nodal hole B in the circumferential wall of the hole A.

Then, when the screw auger S punches the punch, the punch is stopped at the point where the screw auger S hits the punch, and the enlarged blade 6 is expanded by hydraulic pressure in the same manner as described above to form several nodal holes B. Further, at the same time as the mapped holes are filled, a filler such as mortar or cement milk is discharged from the nozzle port 13 of the auger head 3 and the injection port 14 of the auger shaft 1, and the trench hole A and the nodal hole B are filled with this. After the filling is completed, the piston punch 11 is operated to open the enlarged blade 6.
The diameter of the mortar column P is reduced by closing the blade, but during this time the mortar continues to be discharged, and the screw auger S is pulled out to the ground, thereby forming a mortar column P having a plurality of joints E over the top and bottom.
can be created underground. A pile-shaped reinforcing bar C3 is inserted into the unhardened columnar body of the mortar column P thus formed as shown in FIG. This makes it possible to extremely easily and reliably construct a cast-in-place joint pile ○ having an integrally strong joint around its periphery.

By arranging several enlarging blades 6 of the device of the present invention in tandem in the same direction as the auger shaft 1, a large number of nodal holes B can be formed at the same time.

As described above, the present invention involves forming a mortar or cement milk mortar-shaped body in the ground, which has a plurality of knots at arbitrary intervals vertically on the peripheral wall, and installing pile-shaped reinforcing bars in the unhardened mortar columns. Since the roof was inserted, the mortar column, which has joints extending upward and downward, is firmly integrated into the ground, and the mortar column and the pile-shaped rebar hammer with many brocade marks are also firmly integrated. The supporting force due to circumferential friction is extremely strong, and the stress is transmitted into the ground from the reinforcing bar key through the mortar column, and the stress is reliably and smoothly transmitted into the ground. This allows the pile to fully perform its functions and provide strong supporting capacity.

In addition, in the second aspect of the present invention, an expanding blade that can be expanded and contracted by a hydraulic mechanism is provided between the screw blades of the screw auger, so that it can be expanded even though the hole is raised and raised while excavating the soil. The blade can form a nodal hole, and since the expanding blade is supported by a pin shaft so that there is a gap between the auger shaft and the auger shaft, there is no gap between the auger shaft and the expanding blade during normal digging. Even though there was an enlarged blade for forming the nodal hole, it did not normally interfere with drilling, and the opening and closing of the enlarged blade was performed by a hydraulic mechanism. Therefore, the opening/closing is reliable, and the degree of diameter expansion of the enlarged blade can be easily controlled from the outside by adjusting the oil pressure.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the present invention; Fig. 1 is an external view of the construction device of the present invention, Fig. 2 is a plan view of the same, Fig. 3 is a schematic diagram of the construction method, and Fig. 4 is a portrait of a nodal hole. Figure 5 illustrates a completed construction diagram with each pile core inserted. Explanation of symbols 1...Auger touch, 2...Screw wing piece, 3...Auger head, 4...Flange, 5
...Spiral groove, 6...Enlarged blade, 7...Pin koji, 8...
- Swivel mechanism, 9... Oil feed pipe, 10... Hydraulic cylinder, 11... Piston, 12... Mortar injection hole, 13... Nozzle port, 14... Spout hole, 15, 16...
Stopper, 17... Hydraulic pump, S... Screw auger, M... Drive motor, A... Boring hole, B... Node hole, C3... Rebar key, P... Mortar column, E... Knot, D... Knot pile. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. Mortar or mortar having a plurality of joints at arbitrary intervals vertically on the peripheral wall of a screw auger, which is provided with an expanding blade that expands the diameter by hydraulic pressure between the screw blades. 1. A construction method for cast-in-place knotted piles, which comprises forming columns of cement milk in the ground, and inserting pile-shaped reinforcing bars into the unhardened mortar columns to create cast-in-place knotted piles. 2. Support the enlarged blade between the screw blades of the screw auger with a pin shaft so that there is a gap between the inner surface of the enlarged blade and the auger shaft, and when drilling a nodal hole, the expanded blade protrudes from the outside of the screw blade. A construction device for a cast-in-place joint pile, characterized in that it is provided with a hydraulic mechanism that drives the screw blade to expand in diameter so as to reduce the diameter inward from the outer peripheral edge of the screw blade during normal excavation.