JPH0313371B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pile burying method. Generally, in order to bury concrete piles without noise or vibration, an excavator with an auger screw is used, and while pouring a weakly mixed cement milk containing bentonite into the tip of the excavator, a concrete pile with a diameter slightly larger than the pile diameter is injected from the tip of the excavator. While drilling a hole, the excavated soil and cement milk are stirred and kneaded, and when the above excavation reaches the supporting slab, the rich blended cement milk is switched to, and the same stirring and kneading as described above is carried out to form a soil cement-like product.

Then, a construction method is adopted in which the auger screw is pulled out and concrete piles are inserted and buried while the soil cement is still unhardened.

The bearing capacity of this method is achieved by hardening the tip of the pile and the friction effect of cement milk with the soil around the pile. If it hits a road (an old cave), the cement milk to be injected will flow into the old cave, and there will be no cement milk around the pile at all, and there will be a gap between the pile and the ground in the upper part of the old cave, so friction around the pile cannot be expected. Moreover, the piles cannot be used as piles because they have no bending resistance against horizontal action caused by earthquakes, etc.

In this invention, an excavator is constructed of a steel pipe having a diameter larger than that of a ready-made pile and an auger screw inserted into the steel pipe, and the steel pipe and auger screw are driven by a driving machine to raise the excavator from the ground. While digging underground, cement milk is injected using the hole provided in the axis of the auger screw during excavation, and when the tip of the steel pipe reaches a position deeper than the bottom of the old cave, the steel pipe Stop the drive and continue excavating with the auger screw while injecting cement milk, and when the above excavation reaches the supporting solid foundation, switch to rich blended cement milk or cement mortar and continue injecting it. To provide a method for burying piles in which the soil is used as root hardening milk, and then only the auger screw is pulled up so that the steel pipe remains underground, and the pile is inserted into the excavated hole from inside the steel pipe.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In the figure, A is an excavator that inserts and buries ready-made piles a.

The above excavator A includes a drive machine 1 and a drive machine 1.
A steel pipe 2 whose end (upper side in the figure) is detachably connected to the steel pipe 2 and driven in one direction, an auger screw 3 which is fitted into the steel pipe 2 and whose end is connected to the drive machine 1, and this auger screw. It is composed of an auger screw 3 and an auger screw 3 added to the screw 3.

The above-mentioned steel pipe 2 has a diameter approximately 10 cm larger than the diameter of the ready-made pile a to be inserted and buried, and has a length such that when the end reaches near the ground, the tip reaches a position slightly deeper than the depth of the bottom of the old cave. are used,
In the illustrated case, the end of the steel pipe 2 is attached and detached by overlapping the flanges and fixing them by a fastener consisting of a bolt and a nut or other means such as engagement.

Also, the attachment and detachment of the auger screws 3 and 3' to and from the drive machine 1 and the attachment and detachment of the end of the auger screw 3 to and from the lower end of the auger screw 3' are as follows:
In the case shown, the square shaft 4 and the square hole 5 are fitted together,
A tapered hole 6 is provided in the shaft of the auger screw 3, 3' so as to straddle the contact surface between the square hole 5 and the square shaft 4, and a taper pin 7 is driven into this taper hole 6.

The driving machine 1 moves up and down (by winding and unwinding the wire) using the leader mast 9 of the crawler 8 as a guide, and has two axes concentrically, with auger screws 3 and 3' inside. , steel pipe 2 on the outside
are now connected.

In addition, the shaft center of the auger screw 3, 3' is
A through hole 10 is formed.

Next, to explain the pile burying method, first,
As shown in the figure, after setting the auger screw 3 at a predetermined position on the ground and confirming that it is vertical, the steel pipe 2 and the auger screw 3 are rotated by the drive machine 1 and directed from the ground into the ground. excavate.

At this time, a poorly mixed cement milk containing bentonite is injected from the tip of the auger screw 3 using the through hole 10, and the cement milk and the excavated soil are stirred and kneaded to form soil cement.

As shown in Fig. 3, when the tip of the steel pipe 2 reaches a position deeper than the bottom of the old cave B, the driving machine 1 is stopped, leaving the steel pipe 2 and auger screw 3 underground. , the steel pipe 2 and the auger screw 3 are disconnected from the drive machine 1 .

Next, the driving machine 1 is raised, and the end of the replenishing auger screw 3' is attached to the driving machine 1 as shown in FIG. 4, and the tip of the auger screw 3' is left in the ground. Connect the ends of the auger screws 3 that have been screwed together.

After the above connection work is completed, excavation continues while the auger screws 3, 3' are rotated by the driving machine 1.

At this time, a poor blend of cement milk is injected in the same manner as described above.

When the tip of the auger screw 3' reaches a predetermined depth (supporting solid base), the poor mix of cement milk is switched to the rich mix of cement milk or cement mortar, and as the injection progresses, the process shown in Fig. 5 is carried out. Stir and knead with the excavated soil to make root hardening milk C.

Thereafter, as shown in FIGS. 6 and 7, the auger screws 3 and 3' are pulled up, and the ready-made pile a is inserted and buried in the drilled hole.

In addition, instead of the excavator A shown in Fig. 1 above,
As shown in FIG. 9, there is a steel pipe 2 whose upper end is detachable from the drive machine 1, an auger screw 3 which passes through the drive machine 1 and is fitted into the steel pipe 2, and an auger screw 3 whose upper end is attached to the drive machine 1. Using excavator A, which is composed of a drive machine 1' installed to drive the auger screw 3, excavation is carried out from the ground to a position deeper than the bottom of old cave B (see Fig. 10). When the tip of the steel pipe 2 reaches the tip (as shown in Fig. 11), the driving machine 1 is stopped, and the auger screw 3 excavates only, until the above-mentioned excavation reaches a predetermined depth as shown in Fig. 11. When the steel pipe 2 is reached, the auger screw 3 is pulled up together with the drive unit 1 removed from the steel pipe 2, the steel pipe 2 is left underground, and then a ready-made pile a is inserted into the drilled hole from the inside of the steel pipe 2. Good too.

As described above, according to the pile burying method according to the present invention, the steel pipe and the auger screw inserted into the steel pipe are mutually driven by a drive machine to excavate from the ground into the earth. During excavation, cement milk is injected using the hole in the axis of the auger screw, and when the tip of the steel pipe reaches a position deeper than the bottom of the old cave, the drive of the steel pipe is stopped and the auger screw is inserted. As the excavation continues with the screw, cement milk is injected, and when the above excavation reaches the supporting solid foundation, the mixture is switched to cement milk or cement mortar with a rich mixture, and while injecting it, the cement milk is used as a hardening milk. In order to leave the steel pipes in the ground, only the auger screws were pulled up and ready-made piles were inserted and buried in the excavated holes, so cement milk would not flow into the gaps in the old caves due to the steel pipes penetrating the old caves. prevent.

For this reason, there are no gaps around the piles in the old cave ground, and friction can be expected.

In addition, the inside of the steel pipe left underground is hardened with piles and cement milk, and from the part deeper than the old cave to the supporting rock, it is hardened with soil cement made by stirring and mixing cement milk and soil. Since the tips of the piles are hardened with the hardening milk, a friction effect is exerted directly on the surrounding ground along the entire length of the piles, and strong bearing capacity can be expected.

[Brief explanation of drawings]

The drawings show embodiments of the invention.
The figure is a side view of the excavator, Figures 2 to 7 are longitudinal sectional front views showing the order of burying piles, Figure 8 is a cross-sectional enlarged plan view showing the connecting part of the auger screw, and Figures 9 to 11 are The figures up to the drawings are longitudinal sectional front views showing the order of excavation using an excavator of another embodiment. A...Excavator, a...Ready-made pile, C...Milk,
1... Drive machine, 2... Steel pipe, 3, 3'... Auger screw, 4... Square shaft, 5... Square hole, 6...
Tapered hole, 7... Taper pin, 10... Through hole.

Claims (1)

[Claims] 1 A steel pipe and an auger screw inserted into the steel pipe are driven together by a drive machine to excavate from the ground to the ground, and during this excavation, a through hole provided in the axis of the auger screw is When the tip of the steel pipe reaches a position deeper than the bottom of the old cave, the drive of the steel pipe is stopped and excavation continues using only the auger screw, and cement milk is injected. When the above-mentioned excavation reaches the supporting rock, we switch to cement milk or cement mortar with a rich mixture and use it as a hardening milk, and then pull only the auger crease so that the steel pipe remains underground. A pile burying method in which the piles are inserted into a drilled hole from the inside of the steel pipe.