JPS6183718A - Excavating method - Google Patents

Abstract

PURPOSE:To enable to perform excavation through a single machine, by a method wherein a soft layer part in an excavating ground is excavated through rotation of a screw auger, and hard layer of cobble-stone and the like is excavated through hammering by a hammer and rotation of the screw auger. CONSTITUTION:A cylinder body 7 is brought into contact with a ground surface and a soft layer part at the upper layer part of a ground is excavated through rotation of a screw auger 1. After a cutter 6a of an auger 1 is lowered down to a hard layer part of limestone and the like, by feeding with a pressure a compressed air to an air cylinder 9 through an air passage 3 of a shaft 5 as the auger 1 is rotated, the compressed air pressurizes a piston rod 10 to bring a bit 12 into pressure contact with the hard layer part. When a pressure in the air cylinder 9 is increased, a valve 11a is opened, the compressed air is fed to the interior of the piston rod 10 and is exerted on a hammering member 13 to produce striking on the hard layer part by means of a hammer 8.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a milling method used for constructing cast-in-place piles.

[Conventional technology]

Up until now, the excavation method has mainly been based on augers. Various augers have already been developed, but they are aimed at soft ground.
Air hammers or drills were used to excavate hard strata such as boulders, boulders, and bedrock.

[Problem that the invention seeks to solve]

For the reasons described above, conventionally, when the l1iil excavation reaches the hard layer from the soft layer, it is necessary to change the cutting machine and the excavation tool to excavate the hard layer.

For this reason, it takes a lot of work to excavate the ground where the geology differs between the upper and lower layers, and the excavation process requires different hoeing machines halfway through the excavation, which poses problems such as poor construction accuracy.

[Means to solve the problem]

This invention has been devised to solve the above-mentioned problems of the conventional art.
A screw auger that has a cylindrical body with a diameter larger than the shaft and a screw connected to the screw on the outside, and a hammer inside the cylindrical body that hits the excavated ground with compressed air from the air passage. The soft layer in the excavated ground can be excavated by rotating the screw auger, and the solid layer made of boulders, boulders, bedrock, etc. can be excavated by the hammer blow and the rotation of the screw auger. .

[For production]

With this invention having the above configuration, it is possible to excavate the soft layer of the ground by rotating the screw auger, and when the solid layer is reached during excavation, there is no need to change the machine or excavation tool, and the compressed air is used to excavate the soft layer of the ground. The hammer is operated to impact and destroy the hard abdomen, and the excavated material generated there is transferred upward and discharged by the rotation of the screw auger.

Further, the present invention will be explained in detail with reference to illustrated embodiments.

〔Example〕

In the figure, reference numeral 1 denotes a screw auger, which includes a shaft 5 that has a water channel 2 and an air passage 3 inside, a screw 4 on the outside, and a screw 6 that has a larger diameter than the shaft 5 and connects with the screw 4 on the outside. Prepared Sha.

It is composed of a cylindrical body 7 at the tip of the foot.

A hammer 8 is provided inside the cylindrical body 7 for hitting the excavated surface with compressed air from the air passage. This hammer 8 is connected to an air cylinder 9 installed above the cylindrical body 7.
It is provided on the piston rod 10 of. The piston rod 10 is hollow and has a valve device 1 inside the end on the air cylinder side.
1, and a striking actuating member 13 is reliably provided between the valve device 11 and a bit 12 fitted to the tip of the rod.

Furthermore, splines 14a and 14b that fit into each other are vertically provided on the circumferential side of the piston rod 10 and the inside of the cylinder 7, and the hammer 8 can also rotate together with the cylinder 7 via these splines 14a and 14b. It's Nishide.

Reference numeral 15 denotes a plurality of water pipes connected to the water channel 3 of the shaft 5, which are vertically provided outside the cylindrical body 7, and whose lower ends are opened inside the cutting edge 6a at the tip of the screw 6. Note that this water pipe 15 may be provided inside the cylindrical body 7 in some cases.

Next, the excavation method using the screw auger 1 will be explained in more detail with reference to FIG.

FIG. 3: First, the tip of the cylindrical body 7 is grounded on the excavated ground, and the screw auger 1 is rotated in the advancing direction. At this time, the above bit 1
2 is located at the cutting edge 6a at the tip of the screw.

By this rotation of the screw auger 1, the soft layer A in the upper layer of the ground is excavated by the screw 6, and the excavated soil is sequentially sent to the ground surface by the screw 4 around the shaft.

FIG. 4 If the tip of the screw auger 1, that is, the cutting edge 6a at the tip of the screw, reaches the solid layer B of limestone or the like and it becomes difficult to excavate by just rotating the screw auger 1, turn the screw auger 1. At the same time, compressed air is force-fed to the air cylinder 9 through the air passage 3 of the shaft 5. The compressed air in the air cylinder first pressurizes the piston rod 10,
The bit 12 at the tip of the rod is pressed against the solid layer 8. When the pressure inside the air cylinder further increases, the compressed air flows into the piston rod 10 through the valve 1laIfilitU of the valve device 11 and acts on the impact actuating member 13, whereupon the solid portion B is struck by the hammer 8. A blow occurs.

At this time, the air temperature temporarily decreases on the air cylinder side, so the valve 11a is closed again by the spring pressure. Further, the compressed air inside the piston rod after the impact flows out to the outside through an air passage formed in the impact operating member 13 and the rod 12.

The opening/closing operation of the valve 11a is based on the difference between the pressure on the air cylinder side and the pressure of the spring member 11b that presses the valve 1ia. The blows occur continuously.

The fragments of the solid layer B crushed by the hammer 8 are as follows:
The excavated soil is transferred upwards by the screw 6.4 around the rotating screw auger 1.

FIG. 5 As described above, mortar is injected into the hole C which is excavated in the soft layer A by the rotation of the screw auger 1 and in the solid layer nSB by the rotation of the screw auger 1 and the impact by the hammer 8. Injection of this mortar is carried out using the water pipe 15 opened at the tip of the screw auger, that is, the tip of the cylindrical body 7, while pulling up the screw auger 1, which has stopped rotating, as is normally practiced. The injection hole increases as the screw auger 1 is pulled up and becomes a mortar pile.

Fig. 6 Also, after creating a mortar pile, if a reinforcing bar cage or HIE is driven into the pile, it becomes a cast-in-place pile F.

Although the water pipe 15 is used for injecting mortar in the above construction example, it can also be used for injecting excavation water.

〔Effect of the invention〕

As described above, this invention connects a screw auger and a hammer so that soft layers can be excavated by the rotation of the screw, and sand layers can be excavated by the impact and rotation of the hammer. It is possible to excavate pile holes etc. using a single screw auger without affecting the geology.

In addition, there is no need to change machines or excavation tools during excavation, and drilling can be carried out from soft layers to sandy layers, resulting in high accuracy in drilling holes.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of the main part of the screw auger used in the excavation method of this invention, Figure 2 is a plan view taken along the line ■-■ in Figure 1, and Figures 3 to 6 are the steps from excavation to pile construction. FIG. 1...Screw auger 2...Waterway, 3...Air''lEr 4.6...Screw 5...Shaft 7...Cylindrical body, 8...Hammer
12... Bit Patent Applicant Tokki Kogyo Co., Ltd. Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] A cylindrical body having a diameter larger than that of the shaft and having a screw connected to the screw on the outside is connected to the tip of a shaft having a water channel and an air passage inside and a screw on the outside,
Using a screw auger equipped with a hammer inside the cylindrical body that hits the excavated ground with compressed air from the air passage, the soft layer in the excavated ground is excavated by rotation of the screw auger, such as boulders, boulders, bedrock, etc. An excavation method characterized in that excavation of the hard layer is carried out by the impact of the hammer and the rotation of the screw auger.