JPS6353330B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for horizontal ground improvement in civil engineering work.

Note that "horizontal" in the present invention includes an inclination that does not cause any problem during construction.

When building tunnels or underground structures during civil engineering work, it is necessary to prevent the loosening of the ground and deformation of the ground surface due to excavation, and to excavate the tunnels safely. When tunnel 1 is excavated near the ground surface, it is necessary to carry out construction work to prevent the ground above and on both sides from loosening prior to excavating tunnel 1.

Conventionally, pipe roof construction methods have been used to meet the above requirements. As shown in Figure 2a, this construction method involves press-fitting the steel pipe 4 while horizontally digging with an auger excavator 3.
There is an independent method shown in Figure c. Figure 2b shows special joint 5
If the steel pipe sheet pile 5 using a is used, there will be no water leakage or collapse from the surrounding ground. In FIG. 2c, cement milk 6 is poured around the steel pipe 4 to form a roof.

The conventional pipe roof construction method described above uses steel pipe sheet piles and steel pipes, so the material cost is high, and the drawbacks are that it takes time and effort to transport and handle heavy objects such as steel pipes.

The present invention has been made in view of the above-mentioned circumstances. First, pilot excavation is carried out using a pilot rod, and then the pilot rod is replaced with a stirring head having a co-rotation prevention device at the tip. After that, the pilot rod is replaced with a stirring head having a co-rotation prevention device at the tip. Attach one end of reinforcing material such as reinforcing steel, and rotate the stirring blades of the stirring head while spouting the soil solidification material from the spout at the base of the stirring head along the pilot excavation hole, and pull out the stirring head to improve the column. A method of horizontal ground improvement characterized by forming a horizontal ground improvement method, and a method of horizontal ground improvement characterized by constructing a predetermined number of improvement columns at the top and both sides of the tunnel prior to tunnel excavation by the above process, and installing column row walls. The purpose is to provide a method.

A detailed explanation will be given below based on FIGS. 3 to 6. FIG. 3a is an explanatory diagram of pilot excavation showing one embodiment of the present invention, and FIG. 3b is an explanatory diagram of stirring and pulling out using a stirring head equipped with a rotation prevention device.
Figure 4a is a perspective view of the pilot rod, Figure 4b
Figure 4c is a side view of the stirring head with a reinforcing material attached to the anti-rotation device, Figure 4c is a front view of the stirring head, and Figure 4d is a side view of the stirring head with a reinforcing material attached to the swivel at the tip of the excavation shaft. FIG. 5 is an explanatory diagram of the construction order of the present invention, and FIG. 6 is an explanatory diagram of the arrangement of column walls of the present invention.

In Fig. 3a, 7 is a boring machine installed in the starting shaft 8, and the tip of the drilling rod 9 is shown in Fig. 4a.
A pilot rod 10 having a bit 9a at its tip as shown in FIG. 1 is attached with a screw or the like. 11 is a reaching shaft. To carry out the present invention, FIG.
The procedure is as shown in FIG. 5g.

Figures 5a and b: Drilling rod 9 to which pilot rod 10 is attached is rotated and fed by a boring machine from the starting shaft side, and waterless or waterless (extremely small amount) drilling is performed.

FIGS. 5c and d As also shown in FIG. 3a, the pilot rod 10 penetrates the reaching shaft 11 and when the pilot excavation is completed, the pilot rod 10 is removed.

Fig. 5e Attaching the stirring head 12 having a co-rotation prevention device 12d at the tip,
One end of the reinforcing bar 16 is attached to the anti-rotation blade of the stirring head 12, and at the same time, a swivel 13 having a soil solidification material injection hose 13a is attached to the end of the drilling rod 9 on the side of the boring machine, as shown in FIG. 3b. .

Figure 5 f, g Spout 12 at the base of the stirring head 12
While ejecting the ground solidifying material from b (Fig. 4b), filling, excavation, stirring, and extraction are carried out along the pilot drilling hole that was penetrated earlier.
At this time, the co-rotation prevention blade 12d at the tip of the stirring head does not rotate, and the reinforcing bars 16 are buried in the area where the stirring blade 12a rotates and stirs the ground solidification material and soil.

When the above operation is performed up to the starting shaft and the stirring blade is pulled out toward the starting shaft, one improved column 14 is formed. Subsequently, as shown in FIG. 6, column walls 15 are installed by previously constructing the required number of improved columns 14 on the top and both sides of the tunnel 1 to be constructed.

The above-mentioned stirring head having the co-rotation prevention device was first developed by the applicant of the present invention in Japanese Patent Application No. 55-056970.
56-153013), and as shown in FIG.
It is rotatably inserted via f. Therefore, the rotation of the soil (soil clod) that is being stirred by the stirring blade 12a is temporarily stopped by the rotation prevention blade 12d, so that the rotation of the soil (soil clod) that is being stirred by the stirring blade 12a is temporarily stopped.
2a, the soil can be mixed and stirred efficiently, but when using the above-mentioned stirring head in the present invention, the fact that the co-rotation prevention blades do not rotate during construction is used to stir the co-rotation prevention blades. This is provided at the tip of the head, and a reinforcing material such as a reinforcing bar buried in the improved column is attached to the above-mentioned anti-rotation wing.

Therefore, instead of attaching reinforcing materials such as reinforcing bars to the co-rotation prevention blades provided at the tip of the stirring head as described above, a swivel 18 is provided at the tip of the excavation shaft 12e as shown in FIG. etc., the reinforcing material 16 is attached, and the reinforcing material 16 does not rotate due to the friction on the circumferential surface of the reinforcing material 16, and the reinforcing material 16 does not rotate between the excavation shaft 12e and the stirring blade 12a.
You can also use a method of rotating and pulling out.
In this case, an improved column with a reinforcing material such as a reinforcing bar buried in the center can be obtained.

The column wall 15 is connected to the improved column 14 as shown in FIG. 6b.
Construction should be done so that there is a gap between them, or
The pitch p between the axes of the improved columns can be made equal to or less than the improved column outer diameter D so that the improved columns 14 overlap each other as shown in FIG.

To construct a row of pillars that wrap around each other as shown in Figure 6a, first construct an improved pillar at every other pillar, and then construct further improved pillars between the improved pillars to prevent the curvature of the pilot excavation hole. The overlap between the improved pillars is completely completed. Since the improved pillars overlap each other, water leakage from the surrounding ground can be prevented.

As explained in detail above, according to the method of the present invention, construction accuracy can be maintained through pilot excavation, and horizontal ground improvement can be carried out inexpensively and efficiently. It is possible to form a strong improved ground with column walls that are strong against the ground. Therefore, by implementing the horizontal ground improvement according to the present invention before constructing a tunnel or underground structure, it is possible to prevent loosening of the ground and deformation of the ground surface due to excavation.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of horizontal ground improvement when constructing a tunnel near the ground surface under railway tracks, Figure 2 is an explanatory diagram of the pipe roof construction method for horizontal ground improvement, and Figure 3a is an example of the present invention. Fig. 3b is an explanatory diagram of stirring and extraction by a stirring head with a co-rotation prevention device, Fig. 4a is a perspective view of the pilot rod, and Fig. 4b is a co-rotation of the tip. Fig. 4c is a side view of the stirring head with a reinforcing material attached to the prevention device, Fig. 4d is a side view of the stirring head with a reinforcing material attached to the swivel at the tip of the excavation shaft, and Fig. 5 is a front view. FIG. 6 is an explanatory diagram of the construction order of the present invention, and is an explanatory diagram of the arrangement of column walls in which reinforcing materials are embedded. 1...tunnel, 7...boring machine, 8...
Starting shaft, 9... Excavation rod, 10... Pilot rod, 10a... Bit, 11... Arrival shaft, 12... Stirring head, 12a... Stirring blade, 1
2b... spout, 12c... co-rotation prevention device,
12d...Co-rotation prevention wing, 14...Improved column, 1
5... Column row wall, 16... Rebar, p... Pitch, D
...Improved column outer diameter, 18...Swivel.

Claims (1)

[Scope of Claims] 1. A drilling machine installed in the starting shaft is used to rotate and feed a drilling rod equipped with a pilot rod having a bit at the tip, so that the distance between the starting shaft and the destination shaft is horizontal. Perform pilot excavation, and after the pilot rod has penetrated the reaching hole, replace the pilot rod with a stirring head that has a co-rotation prevention device at the tip, and then attach one end of reinforcing material such as reinforcing steel to the co-rotation prevention device at the tip. Reinforcement is carried out in the axial direction by rotating the stirring blades of the stirring head and pulling out the stirring head together with the reinforcing material to the starting shaft while spouting the soil solidifying material from the spout at the base of the stirring head along the pilot excavation hole. A horizontal ground improvement method characterized by forming improved pillars with buried timber. 2 Pilot excavation is performed horizontally between the starting shaft and the destination shaft by rotating and feeding a drilling rod equipped with a pilot rod with a bit at the tip using a boring machine installed in the starting shaft. After the pilot rod penetrates the reaching hole, replace the pilot rod with a stirring head that has a co-rotation prevention device at the tip, then attach one end of reinforcing material such as a reinforcing bar to the co-rotation prevention device at the tip, and insert it into the pilot drilling hole. An improvement in which reinforcing material is buried in the axial direction by rotating the stirring blade of the stirring head and pulling out the stirring head together with the reinforcing material to the starting shaft while jetting out the soil solidifying material from the spout at the base of the stirring head. A horizontal method characterized in that a column wall is installed by forming columns and subsequently forming a predetermined number of improved columns on the top and both sides of the tunnel, underground structure, etc. to be excavated in the above process. Method of ground improvement. 3. The method for horizontal ground improvement according to claim 2, characterized in that there is a gap between the improved pillars forming the pillar row walls. 4. The method for horizontal ground improvement according to claim 2, characterized in that the pitch between the axes of the improved columns forming the column walls is set to be equal to or less than the outer diameter of the improved columns.