JPS6353329B2 - - 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.

Conventional pipe roof construction methods as described above have the drawbacks of high material costs due to the use of steel pipe sheet piles and steel pipes, and the time and effort required 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, after replacing the pilot rod with a stirring head, the ground solidification material is injected from the spout at the base of the stirring head along the pilot excavation hole. A horizontal ground improvement method characterized by forming an improved column by rotating, stirring, and pulling out the stirring head while ejecting water, and by the above process, a predetermined number of improved columns are formed at the top and both sides of the tunnel prior to tunnel excavation. It is an object of the present invention to provide a method for horizontal ground improvement characterized by constructing and installing columnar walls.

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, Fig. 3b is an explanatory diagram of stirring and drawing by the stirring head, Fig. 4 is a perspective view of the pilot rod, and Fig. 4b is an explanatory diagram of the pilot excavation. Side view of the stirring head,
FIG. 4c is a front view of the same, 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, reference numeral 7 denotes a boring machine, which is installed in a starting shaft 8, and a pilot rod 10 having a bit 10a at its tip, as shown in FIG. 4a, is attached to the tip of a drilling rod 9 with screws or the like. 11
is the reaching shaft. To carry out the present invention, first, as shown in FIGS. 5a and 5b, the drilling rod 9 to which the pilot rod 10 is attached is rotated and fed by a boring machine from the starting shaft side, and the drilling rod 9 is rotated and fed from the starting shaft side, and the drilling rod 9 is rotated and fed from the starting shaft side. Perform excavation. When the pilot rod 10 penetrates the reaching shaft 11 and the pilot excavation is completed as shown in Fig. 5c and Fig. 3a,
Remove the pilot rod 10 as shown in (e) and attach the stirring head 12 as shown in (e). In the example shown in FIGS. 4B and 4C, the stirring head 12 has stirring blades 12a at several locations, and the base of the stirring head 12 is provided with spouts 12b for the ground solidifying material. 12c is a co-rotation prevention device having a co-rotation prevention blade 12d, which includes a rotating stirring blade 12a and a non-rotating co-rotation prevention blade 1.
The applicant of the present invention previously filed Japanese Patent Application No. 55-056970 (Japanese Unexamined Patent Application Publication No. 56-056-2000).
153013), the present invention can be carried out more effectively by using a stirring head having this co-rotation prevention device 12c, but the method of the present invention can be carried out more effectively by using a stirring head having the co-rotation prevention device 12c. The present invention is not limited to the use of a stirring head, and a stirring head having only stirring blades may be used. At the same time as the stirring head 12 is attached as shown in FIG. 5e, the swivel 13 having the soil solidification material injection hose 13a is attached to the boring machine side end of the excavation rod 9 as shown in FIG. 3b. Next, the fifth
As shown in Figures f and g, the ground solidifying material is jetted out from the spout 12b (Figure 4b) at the base of the stirring head 12, and the material is filled, excavated, stirred, and pulled out along the pilot drilling hole that was penetrated earlier. I do. 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 a predetermined number of improved columns 14 at the top and both sides of the tunnel 1 to be constructed.

The column walls 15 are constructed so that there are gaps between the improved columns 14, as shown in FIG. 6b, or so that the improved columns 14 overlap each other, as shown in FIG. 6a.
The pitch p between the axes of the improved column can be made equal to or less than the outer diameter of the improved column.

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 improved pillars between the improved pillars to reduce the bending of the pilot excavation hole. , the lap condition between the improved pillars is also 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, horizontal ground improvement can be carried out at low cost and efficiently, and basic preparations can be carried out before constructing a tunnel or underground structure. By implementing the horizontal ground improvement according to the invention, loosening of the ground and deformation of the ground surface due to excavation can be suppressed.

[Brief explanation of the drawing]

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 conventional pipe roof construction method for horizontal ground improvement,
Fig. 3a is an explanatory diagram of pilot excavation showing one embodiment of the present invention, Fig. 3b is an explanatory diagram of stirring and drawing by the stirring head, Fig. 4a is a perspective view of the pilot rod, Fig. 4b 4c is a side view of the stirring head, FIG. 4c is a front view thereof, 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. 1...tunnel, 7...boring machine, 8...
Starting shaft, 9...Drilling rod, 10...Pilot rod, 10a...Bit, 11...Achievement shaft, 12...Stirring head, 12b...Ejection port, 1
4...Improved pillar, 15...Column row wall, p...Pitzchi,
D...Improved column outer diameter.

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. Pilot excavation is carried out, and after the pilot rod has penetrated the reaching hole, the pilot rod is replaced with a stirring head, and then the stirring head is rotated while spouting the ground solidifying material from the spout at the base of the stirring head along the pilot excavation hole. - A horizontal ground improvement method characterized by forcibly stirring the soil and ground solidifying material by stirring and pulling it out to the starting shaft to form an improvement column. 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, the pilot rod is replaced with a stirring head, and then the stirring head is rotated, stirred, and pulled out while jetting the ground solidification material from the spout at the base of the stirring head along the pilot excavation hole. By this, the soil and ground solidification material are forcibly stirred and pulled out to the starting shaft to form an improved pillar, and then in the above steps,
A method of horizontal ground improvement characterized by installing column walls by forming a predetermined number of improvement columns in advance on the top and both sides of tunnels, underground structures, etc. to be excavated. 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 wall. 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.