JP3883686B2 - Diagonal pile drilling method using pressurized water and pressurized water supply equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a foundation structure such as a steel tower foundation or a road bridge of a transmission line constructed in a mountainous area or the like, and in particular, a slant pile foundation slant pile drilling method and a pressurized water supply device for a deep foundation or a circular bottom plate inverted T-type foundation. About.
[0002]
[Prior art]
Conventionally, transmission towers constructed mainly in mountainous areas have been selected based on comprehensive consideration of the characteristics of the superstructure, ground properties, topographic conditions, workability, etc. In many cases, a deep foundation is selected, and in the middle size, a circular bottom plate inverted T-type foundation is selected and a structure is installed thereon.
[0003]
And for the round bottom plate, many bottom-up foundations are used to reduce the construction cost by expanding the bottom plate part against the basic load of compressive force / lifting force received from the steel tower.
[0004]
In this case, a support work is necessary because the excavation of the bottom of the excavation is a drainage excavation, but in general, the work is mainly carried out with a support work for buried oblique pile steel bars.
[0005]
That is, in the excavation of the above-mentioned expanded foundation, a large number of slant pile steel rods that serve as supporters for earth retaining which are inclined so as to reach the natural ground from the height of the upper surface of the expanded bottom portion are embedded in a radial pattern.
[0006]
[Problems to be solved by the invention]
However, when constructing the above-mentioned support for buried pile steel rods using a combination of rock drill and breaker, if the geology is siltstone and there is spring water, rock powder, clay, etc. will be placed in the pit air hole of the rock drill during drilling. Since the chestnut powder contained water and clogged, there was a problem that the drilling operation was stopped each time.
[0007]
In such a case, it takes about 30 to 60 minutes to remove the clogging, and during this time, the drilling operation must be interrupted, and such a situation occurs several times to several times per leg. Repeatedly, it was a big loss of work time.
[0008]
Further, during the drilling operation, a large amount of dust is generated, resulting in poor visibility and sanitary problems, and causes a reduction in work efficiency.
[0009]
[Means for Solving the Problems]
The present invention provides a slant pile drilling method and a pressurized water supply device that eliminates the above-described problems in the hole drilling work, eliminates clogging of air holes, and enables slant pile drilling work to be performed with high efficiency. The solution to this problem is to prevent the adhesion of chestnut powder that clogs the bit air holes during the drilling operation using pressurized water.
[0010]
That is, the present invention embeds oblique pile steel rods radially along the inclined surface of the bottom as a deep foundation of a foundation for installing a steel tower of a transmission line or a bottom expansion support of a circular bottom plate inverted T type foundation. In the rock drilling for drilling the ground by drilling the bit forward and backward by air pressure, drilling the pressure pile from the tip of the rock drilling machine.
[0011]
The pressure water supply system to be injected from the tip of the bit during excavation has a water reservoir for storing water and a water pressurizer for pressurizing the water in the water reservoir. A compressor for driving the bit is provided above the water reservoir. A pressure air hose for introducing compressed air is connected via a pressure adjusting valve, and water whose pressure is adjusted by compressed air from the compressor is guided to a pressure water jet port.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to embodiments shown in the drawings.
FIG. 1 shows an example of a slant pile drilling method according to the present invention. Generally, a foundation such as a steel tower of a transmission line constructed in a mountainous area is a deep foundation or a circular bottom plate inverted T-type foundation 1 (FIG. 5). Reference) Although the base 1 has a trapezoidal upper part embedded in the base 1 at an appropriate depth from the ground surface, the widened bottom portion 1a of the base body is formed around the top surface from the ground surface. It has a height up to the upper surface of the expanded bottom portion 1a and is surrounded by an annular liner 2 for protecting a worker working inside, and the inclined pile hole 4 is formed by expanding the bottom of the foundation. It is constructed so as to go from the top to the ground along the inclined surface 1b formed around the portion 1a.
[0013]
This drilling hole 4 is made by using a rock drill 3 while an operator stands on the upper surface of the foundation body 1 in the liner 2, and on the ground is water such as a compressor 5, a water pressurizer 6, and a drum can. A reservoir 7 or the like is installed, and the air compressed by the compressor 5 is sent to the water pressurizer 6 and the other to the rock drill 3 through the air hoses 8 and 9, respectively. It is sent to the pressurizer 6 through the hose 10, pressurized here, and sent to the rock drill 3 through the high-pressure hose 11. In addition, the water to the water reservoir 7 is supplied through a hose 12 from a water source (not shown).
[0014]
FIG. 2 is a partially broken view of the water pressurizer 6 of FIG. 1. Pressurized air compressed by the compressor 5 (pressure is, for example, 5 to 7 kg / cm ² ) is regulated by the regulating valve 15. The pressurized air (the pressure is, for example, ^{2 to 3} kg / cm ² ) pressurizes the water in the water pressurizer 6, and the pressurized water pushed out from the water pressurizer 6 passes through the high-pressure hose 11 as described above. And reaches the pit 17 of the rock drill 3. A pressure water jet 13 is provided at the tip of the rock drill 3 bit 17.
[0015]
In FIG. 2, reference numeral 14 is a water gauge, 15a is a pressure gauge, and 16 is an adjustment valve for adjusting the amount of water.
[0016]
Therefore, when drilling with the rock drill 3, the sprayed pressure water from the pressure water outlet 13 at the tip of the bit 17 liquefies the chestnut powder etc. that caused the clogging of the air holes. The clogging of the air holes of the rod 17 and the rod 18 is eliminated.
[0017]
In this case, the water amount is adjusted by adjusting the pressure adjusting valve 15 provided in the upper part of the water pressurizer 6, and the water amount is adjusted by adjusting the adjusting valve 16 provided near the handle 3 b of the rock drill 3. Can be jetted.
[0018]
FIG. 3 is an enlarged view of the oblique pile portion of FIG. 1, and shows a state where the construction of the oblique pile hole 4 is completed and the steel bar 19 is driven by a breaker (not shown).
[0019]
The details of the liner 2 are such that the inner peripheral wall is backed and the mortar 2a is formed so that the top and bottom are adjacent to each other, and a reinforcing ring 20 such as H-shaped steel is installed around the lowermost part. A support portion 21a that hangs down is provided, and the upper end side of the steel rod 19 is supported by the support portion 21a.
[0020]
The dimensions of the base body 1a are as shown in FIG. 3, for example. The size of the steel bar 19 is, for example, about 32 mm in diameter and about 1500 mm in length.
[0021]
FIG. 4 is a plan view showing a state in which slant piles are driven, and a large number of the steel bars 19 are radially formed with respect to the center of the bottom expanded portion 1a of the foundation body (in the example shown, 40 per leg). Is embedded, thereby stabilizing the bottom expanded portion 1a of the base body.
[0022]
FIG. 5 shows an example of a state in which the steel tower 22 is installed on the upper part of the upper foundation body 1c, and the lower part of the expanded bottom part 1a of the foundation body supporting the legs of the steel tower 22 is formed by a circular bottom plate inverted T-type foundation. . In this case, the liner 2 is removed or embedded in the ground as it is.
[0023]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
1) According to the experimental results, when compared to the conventional air blow method, the workability of the rock drilling machine is less than the conventional 1.7 days (per leg) in the pressurized water blow method according to the present invention. In the invention, since there was no interruption due to removal of clogging of the air holes of the bit and rod, the time was significantly reduced to 1.0 days.
2) Regarding workability, the bit that was frequently generated in the conventional method even in the clay layer in the mudstone ground, which was the least compatible, compared to the state of only air pressure by adding water pressure effect by sending water together with air, Since the clogging of the air holes of the rod is eliminated, the removal work is not necessary, thereby enabling a smooth continuous work.
3) As for safety, since dust generated in large quantities by sending water is not generated at all, safety and hygiene are improved. As a result, workability is improved.
4) With regard to work and economy, the frictional heat generated between the rock and the bit is suppressed by the cooling effect of the water, and drilling work can be performed while cooling the bit, reducing the burden on the bit and durability. -Significantly improve work efficiency and slow down the deterioration rate, so it improves economically.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing an example of a diagonal pile drilling method according to the present invention.
FIG. 2 is a structural diagram showing a part of the water pressurizer of FIG.
FIG. 3 is an enlarged view of the diagonal pile portion of FIG. 1;
4 is a plan view of FIG. 3. FIG.
5 is an external view showing a state where a transmission tower tower is attached to the circular bottom plate inverted T-type foundation of FIG. 3; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Expanded foundation 1a, such as a steel tower 1a Expanded bottom part 1b Inclined surface 3 Rock drill 3b Handle 4 Inclined pile hole 5 Compressor 6 Water pressurizer 8, 9 Air hose 11 High pressure hose 13 Pressure water outlet 15 Air pressure adjustment valve 15a Pressure gauge 16 Water amount adjusting valve 17 Bit 18 Rod 19 Steel rod 22 Steel tower

Claims (1)

A slant pile for burying slant pile steel bars radially along the inclined surface of the bottom as a deep foundation of a foundation for installing a steel tower of a transmission line or a bottom expansion support for a circular bottom plate inverted T type foundation For drilling, drilling holes by jetting pressure water from the tip of the bit while advancing and retracting the bit of the rock drill with air pressure, the pressure water supply system includes a water reservoir and a water reservoir. There is a water pressurizer that pressurizes the water in the reservoir , and a pressure air hose that introduces compressed air from the compressor for driving the bit is connected to the upper part of the reservoir via a pressure adjustment valve, and the pressure is increased by the compressed air from the compressor. A pressurized water supply apparatus characterized in that the adjusted pressurized water is guided to a pressure water jet outlet.

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