JPS5827366B2 - Head reinforcement pile construction equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for constructing head-reinforced piles that can support upper loads and sufficiently resist lateral forces caused by earthquakes, etc. The purpose of the present invention is to provide a device for extremely economically drilling a pile hole that increases the diameter of the hole near the pile head in order to strengthen the resistance against directional vibrations, and for creating a corresponding pile. It is something.

It goes without saying that foundation piles must have the ability to support upper loads, but they must also have cross-sectional properties that can sufficiently resist lateral forces caused by earthquakes and the like.

Therefore, when determining the cross-section of foundation piles, the necessary pile diameter to ensure sufficient resistance to lateral forces often has to be larger than the required pile diameter for vertical bearing capacity, especially when Consideration should be given to the pile head close to the ground surface.

In order to increase the diameter of the pile head in order to provide sufficient lateral resistance, conventionally an excavator with a small diameter auger inserted into a small diameter casing was used to remove cement and water from the tip of the screw auger. After performing primary excavation while spouting a mixture of cement and water, the work is temporarily stopped, and a mixture of cement and water ( Secondary excavation was carried out while squirting cement milk solution (g), and the pile head became large in diameter, and the head was reinforced with so-called fill cement, which is a mixture of a mixture of cement and water and excavated earth and sand. It was being created.

However, in such a conventional example, there was a problem that secondary excavation was required, which required a considerable amount of labor and increased construction costs.

The present invention aims to eliminate such conventional drawbacks, and an example of the implementation of the present invention will be explained with reference to the drawings.1. As shown in Fig. 1, the top of the small diameter casing 1 (that is, the normal diameter one) is inserted into the root of the large diameter casing 2, and the outer circumference of the small diameter casing 1 and the inner circumference of the large diameter casing 2 are connected. Several drilling blades 3 are circumferentially welded at appropriate intervals between the casings 1 and 2 to connect them, and the drilling blades 3 are used to remove earth and sand from the lower part of the large-diameter casing into the casing by rotating the casing. The large-diameter casing 2 is tilted in the direction of pushing into the large-diameter casing 2, and the large-diameter casing 2 is provided with a soil removal window 4 at an appropriate location, and its rotating motor box 5 is installed on the top. Large diameter and small diameter screw auger with 6.7 8゜9 screw auger for mud stirring excavation of different diameters (f) inserted 1. into the top of the large diameter auger screw 8 casing The apparatus is equipped with an auger screw motor box 10 that houses a motor that drives in the opposite direction to the rotational direction of the pile driver (not shown), and 11 is a small-diameter screw auger 9. This is a bit attached to the tip of the small diameter shaft 7.

Incidentally, instead of the screw auger described above, a mud stirring auger may be used which is attached to the center of the stirring plate shaft over its entire length.

To use the above device of the present invention, first place the center of the irregularly-shaped combined screw auger Y for mud stirring excavation in accordance with the site position where the pile is to be constructed, and then connect the combined screw auger Y and the irregularly-shaped combined casing X. When the respective motors are activated and rotated in different directions to start excavating the stratum, the soil excavated by the bit 11 of the small-diameter screw auger 9 rises inside the small-diameter casing 1 and is discharged into the large-diameter casing 2. It is discharged to the ground through the earthen window 4.

As the excavation progresses, the lower end of the large-diameter casing 2 comes into contact with the ground surface, and as the large-diameter casing 2 rotates, the drilling blade 3 drills the earth and sand at the bottom of the large-diameter casing 2.
With the rotation of the large-diameter screw auger 8, the earth and sand are pushed up inside the large-diameter casing 2 through the gap between the excavation blades 3, and are discharged from the earth removal window 4, while the large-diameter casing 2 also advances deep into the ground.

On the other hand, at the same time as the drilling starts, a mixture of cement and water, that is, a cement milk solution, which has flowed into the auger shaft 6.7, is discharged from the tip of the bit 11, and drilling continues as desired (see Fig. 4). After excavation has been carried out to a depth of
When the entire length of the pile is pulled out of the ground, a large-diameter hole is formed near the position of the pile head (see Figure 4).Then, a ready-made pile is inserted into the hole and all work is completed (see Figure 4). (See Figure 4)
.

When the fill cement (a mixed solution of cement and water mixed with excavated soil) in the hole reaches a material age that provides full strength, a complete pile is completed.

In the present invention, as described above, the auger for mud stirring excavation having a large diameter and a small diameter is inserted into the casing which is a combination of a small diameter casing and a large diameter casing.
As with the conventional method, a small-diameter screw auger is inserted into a small-diameter casing and excavation is performed using an excavator, and then the work is temporarily stopped.The excavator for secondary excavation is pulled up and a large-diameter screw is inserted into a large-diameter casing. There is no need for complex construction work that consumes labor and time, such as replacing it with an M11 machine with an auger inserted before starting work and performing secondary excavation, allowing continuous excavation at once. In addition, in the present invention, the top of the small-diameter casing is inserted into the root of the large-diameter casing, and the outer periphery of the small-diameter casing and the inner periphery of the large-diameter casing are separated. The two casings are joined by surrounding welding with several drilling blades placed at appropriate intervals between them, and the drilling blades are used in such a way that earth and sand at the bottom of the large diameter casing is pushed up into the casing as the casing rotates. Because it is tilted in the direction, even if the diameter of the temporary large-diameter casing is extremely large compared to the diameter of the small-diameter casing, the large-diameter casing will not be subjected to the above resistance when it advances underground. Therefore, it is possible to perform excavation work smoothly.

A reinforcing steel cage, iron pipe, etc. may be inserted into the large diameter head portion of the fill cement pile created in this way, or
Prefabricated concrete piles or steel piles may be inserted.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view of a screw-auger with a connecting casing of different diameters showing one embodiment of the device of the present invention, and Fig. 2 is an enlarged cross-sectional view taken along lines A and A in Fig. 1. side view,
FIG. 3 is an enlarged partially cutaway front view showing the joint between the small diameter casing and the large diameter casing in FIG. 1, and FIG. FIG. 1...Small diameter casing, 2...Large diameter casing, 3...Drilling blade, X...
Different diameter combined casing, Y...Auger for different diameter combined mud stirring excavation.

Claims (1)

[Claims] 1. Insert the top of the small-diameter casing into the root of the large-diameter casing, and surround the outer circumference of the small-diameter casing and the inner circumference of the large-diameter casing with several inclined drilling blades at appropriate intervals. The two casings are joined together by welding, and the drilling blade is tilted in such a direction that the earth and sand at the bottom of the large diameter casing is pushed up into the casing by the rotation of the casing, and the large diameter and A head-reinforced pile construction device in which a small-diameter combined mud agitation excavation auger is inserted and rotated in the opposite direction to the casing.