JPS63171919A - Cast-in-place concrete piling work - Google Patents

Abstract

PURPOSE:To raise the efficiency of piling operation by a method in which outer and inner cylindrical excavating members are mutually reversely turned to form a pin in the ground, the inner excavating member is drawn out, a caged reinforcement is inserted and concrete is placed, and the cylindrical excavating member is pulled out. CONSTITUTION:An outer casing screw 9 with an excavating blade 13 and an inner casing screw 11 with an auger head 15 are rotationally driven in mutually opposite directions by drivers 21 and 23 to excavate the ground. When the tips of the screws 9 and 11 reach rocked, the screw 11 is drawn toward the direction of YC out of the screw 9 while being turned toward the direction of arrow YB to discharge soil, and remaining soil and slime are discharged by a specific bucket. A reinforcing bar cage 31 is inserted into the casing 9 and ready-mixed concrete 35 is placed through a tremie tube 33. The tube 33 is then pulled out and after a given time period, the casing 9 is turned alternately to the left and right directions to pull it out to the direction of arrow YD to form a cast-in-place concrete pile 37.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cast-in-place concrete pile construction method, and particularly to a construction method that uses a cylindrical excavation member (casing screw) along the entire excavation length.

[Conventional technology] Conventionally, as a cast-in-place concrete pile construction method in which piles are constructed by mechanical excavation, the all-casing (bed) method is used, in which the casing tube is oscillatedly press-fitted and excavated with a hammer grab (1985 edition "Architecture"). ``Guidelines for Construction Supervision'' Chapter 4, Section 5 (Published by the Management and Maintenance Association).

[Problems to be Solved by the Invention] However, in the conventional technology, there is a limit to the pushing force and force of the casing tube of the excavator, and there is a problem that efficiency decreases significantly depending on the ground, pile diameter, or excavation depth. Ta. Furthermore, if there is a fine layer of sand beneath the surface of the water, the surrounding sand is compacted by the seepage flow of water flowing downward along the outer surface of the casing and vibrations caused by the rocking, causing the problem that the casing cannot move.

The purpose of the cast-in-place concrete pile construction method of the present invention is to solve the above problems and improve the efficiency of constructing piles.

[Means for Solving the Problems] As a means for achieving the object of the present invention, the cast-in-place concrete pile method of the present invention includes: a cylindrical excavation member having an excavation blade at the tip; and a rotatably installed inside the cylindrical excavation member. a screw-shaped internal excavation member and a screw-shaped internal excavation member that are rotated in opposite directions to form an excavation hole, and after forming the excavation hole, the internal excavation member is extracted from the cylindrical excavation member, and the cylindrical excavation remains in the excavation hole. Insert a cage reinforcement into the member, pour concrete into the cylindrical excavation member into which the cage reinforcement has been inserted, and after placing the concrete, pour the cylindrical excavation member from the excavation hole, and pour the concrete into the cylindrical excavation member. The gist is to form a pile.

[Function] The cast-in-place concrete pile construction method of the present invention first excavates the ground by rotating the cylindrical excavation member and the internal excavation member in opposite directions to each other, and then excavates the ground with the excavation blades at the tips of both of the excavation members. The excavation hole is formed while removing soil with the screw.

Next, the internal excavation member is pulled out leaving the cylindrical excavation member in the excavation hole, and the cage-shaped reinforcement (
For example, reinforcing bars) are inserted and concrete is poured. After placing the concrete, only the cylindrical excavation member is used from the excavation hole. As a result, a concrete pile is formed in the excavated hole.

[Embodiment] Next, an embodiment of the cast-in-place concrete pile construction method of the present invention will be described based on the conceptual diagram of FIG. 1 showing the flow of work.

In the cast-in-place concrete pile construction method of this embodiment, first, an excavation hole for forming a concrete pile is auger-drilled using the auger device 1 shown in Fig. 2 (Step SA).
. The auger device 1 shown in FIG. 2 includes an excavating section 3 that excavates the ground, a driving section 5 consisting of an electric motor or the like that rotates the excavating section 3, and a support section 7 that supports the excavating section 3 and the driving section 5. It is composed of etc. The excavation section 3 is composed of a cylindrical outer casing screw 9, which is a cylindrical excavation member, an inner auger screw 11, which is an internal excavation member, and the like. An excavation blade 13 is provided at the tip of the outer casing screw 9, and an excavation blade (auger head) 15 is provided at the tip of the inner august screw 11.

The support section 7 includes a self-propelled section 17, a support column 19', and the like.

As shown in FIG. 3, in the auger device 1 having the above configuration, the outer casing screw 9 and the inner auger screw 11 of the excavating section 3 are arranged in opposite directions so that the outer casing screw 9 and the inner auger screw 11 cancel rotation torque with each other. 21 and the drive section 23 of the inner auger screw 11.

The excavating blades 13 and 15 of the excavating section 3 excavate the ground ET until the excavating section 3 reaches the bedrock GT which is a predetermined ground in the direction of the arrow YA force.

The auger device 1 used for the auger drilling described above was previously published by the applicant of the present application in Japanese Patent Application No. 156689/1989 (see Figure 4) or Japanese Patent Application No. 183191/1983 (see Figure 5).
You may use the technique disclosed in . The technique shown in FIG. 4 above forms a spiral guide projection 25 on the outer periphery of the outer casing screw 9, and
This improves excavation efficiency by removing the earth and sand around the excavation. The technique shown in FIG. 5 allows the outer casing screws ga and gb to be easily connected by the joint member 27, thereby making it easier to drill deeper holes with an auger than in the past.

Next, as shown in FIG. 6, the inner auger screw 11
While rotating it in the direction of arrow YBC, handle it from the outer casing screw 9 in the direction of arrow YC,
Discharge the earth and sand inside the outer casing screw〇 (first
Step SB in the figure).

Following the soil removal by the inner auger screw 11, as shown in FIG. 7, the remaining soil and slime in the outer casing screenie 9 are discharged using the special packet 29 (Step SC in FIG. 1), and after the slime is processed. Excavation depth measurement (
Check the bottom of the pile) etc. (Step SD).

Next, the reinforcing bar cage 31 is
are assembled, and the reinforcing bar cage 31 is inserted into the outer casing screw 9 (installation of reinforcing bars) as shown in FIG. 8 (step SE in FIG. 1).

Next, as shown in FIG. 9, the tremor tube 33 is inserted into the reinforcing bar cage 31 (step SF in FIG. 1).

Next, as shown in FIG. 10, using the toremi tube 33,
Concrete 35 is poured into the outer casing screw 9 (step SG in FIG. 1), and after a predetermined amount of concrete 35 is poured, the tremor pipe 33 is handled.

After a predetermined time of pouring the concrete 35, as shown in FIG. 11, while the inner auger screw 11 prevents the reinforcement cage 31 from becoming stiff, the outer casing screws 9 are slowly turned left and right alternately to apply a force of arrow YD. As shown in FIG. 12, construction of the cast-in-place concrete pile 37 is completed as shown in FIG. 12 by pulling up from the ground ET (step SH in FIG. Step SI).

As described above, the cast-in-place concrete construction method of this embodiment allows easy excavation of gravel, cobblestones, boulders, etc. in the middle part, and excavation of bedrock.Furthermore, the use of an auger device that easily removes soil makes it possible to excavate the ground with high efficiency. However, by performing this method reliably, the construction efficiency of cast-in-place concrete piles can be improved, and the tip of the pile can be embedded into the bedrock, which is an extremely excellent effect.

Moreover, it has the excellent effect of being able to perform construction with low noise and low vibration.

Note that the present invention is not limited to the above-described embodiments, and various embodiments can be implemented without changing the gist of the present invention.

[Effects of the Invention] The cast-in-place concrete pile construction method of the present invention allows the ground to be excavated with high efficiency using the tips of the excavating members that rotate in opposite directions, and moreover, the earth and sand can be discharged while excavating using the screw-shaped internal excavating member. Therefore, the efficiency of forming the excavated hole is significantly improved, and as a result, the construction time for concrete piles can be extremely shortened, and the construction can be performed with low noise and low vibration, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing the work flow of an embodiment of the present invention, FIG. 2 is a configuration diagram of an auger device used in the embodiment, FIG. 3 is an explanatory diagram of the excavation state of the auger device of the embodiment, and FIG. 4 and 5 are explanatory diagrams showing the various aspects of the orga device of the embodiment, FIG. 6 is an explanatory diagram of the handling of the inner auger screw of the embodiment, and FIG. 7 is an explanatory diagram of the slime processing of the embodiment. Figure, 8th
The figure is an explanatory diagram of setting up reinforcing bars in the example, Figure 9 is an explanatory diagram of a set of tremor pipes in the example, Figure 10 is an explanatory diagram of pouring concrete in the example, and Figure 11 is an explanatory diagram of the concrete placement in the example. FIG. 12 is an explanatory diagram of the river bed of the outer casing screw, and FIG. 12 is an explanatory diagram of the cast-in-place concrete pile of the embodiment in a completed state. 1...Auger device 3...Drilling part 5...Drive part 7...Support part 9...Outer casing screw 11...Inner auger screw 13.15...Drilling blade

Claims (1)

[Scope of Claims] A cylindrical excavation member having an excavation blade at the tip and a screw-shaped internal excavation member rotatably provided within the cylindrical excavation member are rotated in opposite directions to form an excavation hole, and the above-mentioned excavation hole After forming, the internal excavation member is extracted from the cylindrical excavation member, a cage-shaped reinforcement is inserted into the cylindrical excavation member left in the excavation hole, and the cage-shaped reinforcement is inserted into the cylindrical excavation member. A cast-in-place concrete pile method in which concrete is poured into the hole, and after the concrete is poured, the cylindrical excavated member is pulled out of the excavated hole to form a concrete pile.