JPS6035489B2 - Construction method and equipment for cast-in-place knot piles - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for constructing knotted piles and an apparatus therefor.

Conventionally, when driving foundation piles, the friction method using so-called knotted piles, in which several knots are attached to the pile column surface, has been widely used in order to provide frictional support with the surrounding area. Recently, as a construction method for carrying out this process silently and without vibration, a screw auger is used to form a hole in the specified ground, filler such as mortar or cement milk is injected into the hole, and then the inside of the mortar column is injected. A cast-in-place method is being developed that involves inserting knotted piles into the ground. However, because the shape of the pile column constructed by this construction method is approximately cylindrical, the supporting force due to friction around the pile is extremely low, and it is extremely difficult to ensure strong stability using only the tip of the pile. Although knotted piles were used at great length, there was a serious drawback in that the functions of the knotted portions were wasted and the effects of the knotted piles could not be expected at all.

The present invention aims to fundamentally solve this drawback, and uses a screw auger that is provided with an enlarged blade between the screw blades that automatically spreads the friction due to the Tonosho resistance, etc. to vertically extend the peripheral wall. Then, a column of mortar or cement milk having a plurality of knots at arbitrary intervals is formed in the ground, and a ready-made pile with knots is inserted into the unhardened mortar column, and the knots and knots of the mortar column are inserted. By constructing cast-in-place knotted piles by matching the joints of ready-made piles, the function of the knotted ready-made piles can be fully demonstrated, and furthermore, the foundation can be strengthened by the supporting force created by the circumferential friction of the external knotted piles. The purpose is to make it stable and strong, and to carry out the construction quickly and reliably.

An example of the construction method of cast-in-place knot piles and the configuration of the device according to the present invention will be described below 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 includes enlarged blades 6 that are formed in the spiral grooves 5 of the screw blades 2 in the direction of Wakkanai along the outer periphery of the screw blades 2. One or more sheets are supported by a pin shaft 7 so as to be openable and closable.

The enlarged blade 6 is normally supported so as to form a gap through which soil can pass between the inner surface of the enlarged blade 6 and the auger touch 1 during excavation. The enlarged blade 6 has a blade size that is larger than the diameter of the hole A drilled by the screw auger S when it is expanded, and when the auger rotates normally, it closes in the spiral groove 5 and is reduced in diameter. However, by reversing the auger, the auger is automatically expanded and rotated due to the resistance of the surrounding soil, and the auger further excavates the circumferential wall of the trench A to form a nodal hole B with a larger diameter.

8 and 8' are screw wing pieces 2 that support the enlarged blade 6.
A stopper protruding from the inner surface of the auger shaft 1 and a part of the auger shaft 1 prevents the inner weave 6 of the enlarging blade 6 from opening and closing when the enlarging blade 6 is expanded or closed.
′ is valid and limits the range of the ship's side-closing operation. That is, when the screw auger S rotates normally, the enlarging blade 6 hides in the helical groove 5 and prevents its protrusion, allowing the screw auger S to perform the digging operation smoothly, and also prevents the enlarging blade 6 from returning naturally when drilling an enlarged hole. This allows powerful excavation to be achieved by completely blocking the movement, and at the same time, the earth and sand descending from between the screw blades 2 can be reliably stopped in the tube. Furthermore, by changing the supporting position of the pin shaft 7 or the blade size of the expanding blade 6 by locking the end portion 6' of the expanding blade 6 to the shaft surface stopper 8', it is extremely easy to enlarge the protrusion of the expanding blade 6. It can be adjusted to any desired gunwale. Reference numeral 9 is a nozzle port 1 which is connected to the lower end of the auger head 3 and is a port for injecting mortar, cement milk, etc., to conduct the inside of the auger koji 1.
0, but if the spout 11 is also provided in the part of the auger shaft 1 that supports the enlarged blade 6, mortar and cement milk can be reliably sent not only to the tip of the auger but also to the joint pile B. Pillars can be filled.

Although the above embodiment has a structure in which the enlarging blade 6 automatically expands and closes due to the Tonosho resistance, the present invention is not limited to such a structure; for example, as shown in FIGS. A rod 13 provided with an L-shaped fishing stop 12 is arranged in parallel with the auger shaft 1 so as to be movable up and down.By operating the rod 13, the fishing stop 12 is moved to the enlarged blade 6 when the auger rotates forward. The rod 13 is locked and housed in the spiral groove 5, and when the arm hole B is to be drilled, the rod 13 is pulled up to release the lock of the fishing stop part 12 and the auger is rotated in the normal direction in the same manner as described above. If so, the enlarging blade 6 can be automatically enlarged by the Tonosho resistance.

0 Also in this case, naturally, the green outer periphery of the end 6' of the enlarging blade 6 comes into contact with the stopper 8, and the range of enlarging is restricted.

Moreover, in the case of this embodiment, the above-mentioned nodal hole B drilling work performed by reversing the screw auger S can be easily performed and completed by pulling up the rod 13, and several holes can be removed in the auger axis direction. It is also possible to form a plurality of nodal holes B at the same time by arranging the enlarged blades 6 in a column. Next, a method for constructing cast-in-place knot piles using the above-mentioned device will be described. The screw auger S having the enlarged blade 6 is rotated by the drive motor M, and a pile hole A is dug in the ground where a desired foundation pile is to be constructed.

When the excavation reaches a predetermined depth, the rotation is stopped and the screw auger S is reversed, and the expanding blade 6 automatically expands due to the surrounding pressure resistance and further enlarges the diameter on the peripheral wall of the borehole A. Drill a nodal hole B.

Also, at the same time as such a hole, the nozzle port 1 of the auger head 3
A filling material such as mortar or cement milk is discharged from the injection row 1 of the auger shaft 1 or the like, and the dug hole A and the nodal hole B are filled with this.

When the above-mentioned filling is completed, the screw auger S is returned to normal rotation and the enlarged blade 6 is opened to reduce the size of the blade, but the screw auger S is returned to the ground while discharging the filler material such as mortar. By punching, a mortar column P having joints E can be created underground. In addition, when removing the auger, the removal is stopped at the number and location of joints E, etc., and the auger is rotated in the opposite direction in the same manner as described above, and the hole is expanded with the expander blade 6 and filled with mortar. As a result, mortar columns P having several joints E at appropriate intervals can be easily constructed underground.

Next, before the filling material to be filled is hardened in the mortar column P formed by the above method, a knotted ready-made pile C having several knots R is placed as shown in Fig. 7. The joints R are inserted and arranged so as to correspond to the joints E of the mortar pillar P, and then they are solidified to form a large-diameter and strong pile pillar that can be easily placed underground. Therefore, it is possible to carry out the construction.

As described above, the present invention involves forming columns of mortar or cement milk in the ground having a plurality of knots at arbitrary intervals vertically on a peripheral wall, and inserting ready-made knotted piles into the hardened mortar columns. Therefore, a mortar column having knots extending above and below is firmly integrated into the ground, and a prefabricated knotted pile having knots above and below is firmly integrated into the mortar column. The bearing capacity due to surface friction is extremely strong, and the stress is transmitted from the knotted ready-made pile to the ground through the mortar column, and the knots of the mortar column are matched with the knots of the knotted ready-made pile. Therefore, stress is reliably and smoothly transmitted from the joints of the knotted ready-made pile to the joints of the mortar pillar, and stress is reliably and smoothly transmitted from the joints of the mortar pillar to the ground.

Therefore, according to the present invention, stress is reliably and smoothly transmitted into the ground, allowing the pile to fully perform its functions and providing a strong supporting force. Further, in the second invention of the present invention, an expanding blade is arranged between the screw blades of the screw auger, which automatically expands the sex due to the Tonosho resistance and shrinks inward from the outer periphery of the screw blade during normal excavation. Therefore, although it is a device that lifts the soil upward while excavating the soil and makes a hole, it can form a node hole with an enlarged blade, and moreover, a gap is usually formed between the enlarged blade and the auger shaft during excavation. Since the enlarged blade is supported by a pin shaft on the outer periphery between the screw blades, it is possible to raise the hole through the gap between the auger shaft and the enlarged blade during normal excavation. Even if there is an enlarged blade for forming, it usually does not interfere with excavation.

[Brief explanation of drawings]

The drawings illustrate embodiments of the present invention, and FIG. 1 is an external view of the construction apparatus of the present invention, FIG. 2 is a plan view of the same as above, FIG. 3 is a view of another embodiment of the above, and FIG. 4 is a plan view of the same as above. , FIG. 5 is a schematic illustration of the construction method, FIG. 6 is a diagram of a drilled hole in a knot hole, and FIG. 7 is a diagram of a completed construction in which a ready-made knotted pile can be inserted. Explanation of symbols, 1...Auger shaft, 2...
・Screw wing piece, 3...Auger head, 4
．． ．．・．． ...Flange, 5...Spiral groove, 6...
...Enlarged blade, 7...Pin shaft, 8...
Stopper, 9...Mortar pouring hole, 10...
... Nozzle port, 11 ... Mortar injection port, 12
...Fishing stop part, 13...Rod, S...
... Screw auger, M ... Drive motor, A ... Drilling hole, B ... Nodal hole, C.
... Ready-made pile with knots, R ... Same joint part, P...
...Mortar column, B...Knot, D...
Knot pile. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Scope of Claims] 1. A screw auger that is provided with an expanding blade that automatically expands the diameter due to earth pressure resistance etc. between the screw blades, and a plurality of joints are formed vertically on the peripheral wall at arbitrary intervals. forming a column of mortar or cement milk in the ground,
A cast-in-place knotted pile is created by inserting a knotted ready-made pile into the unhardened mortar column and making the knotted portion of the mortar column correspond with the knotted portion of the knotted ready-made pile. Construction method of knotted piles. 2 An enlarged blade is placed between the screw blades of the screw auger that automatically expands in diameter due to earth pressure resistance and contracts inward from the outer periphery of the screw blade during normal excavation. A construction device for cast-in-place joint piles, characterized in that an enlarged blade is supported by a pin shaft on the outer periphery between the screw blades so that a gap is formed between the blade and the auger shaft.