JP2000226982A - Grouting reinforcing method in tunnel excavation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the efficiency of work and definitely improve and reinforce a target place. SOLUTION: A preceding heading 2 having its center O located outside the cross section of a main tunnel 1, and is almost on the vertical center line CL of the cross section is located above the cross section of the main tunnel 1 to be excavated, and the preceding heading 2 is driven, straight-shaped grouting pipes 10 are respectively inserted from the heading 2 to a region above the cross section of the main tunnel 1 at both the sides sandwiching the vertical center line CL, and the grout is injected through the grouting pipes 10, thereby reinforcing the target region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grouting reinforcement method for tunnel excavation.

[0002]

2. Description of the Related Art When excavating a tunnel with low autonomy, prior to excavation of a main shaft, the surrounding ground is reinforced by grouting.

[0003] This grout injection can be performed by inserting an injection pipe from the ground at a place where the tunnel is shallow from the surface of the ground, but grout cannot be injected from the ground deep below the ground.

Therefore, it is known to reinforce grout by using a small diameter shaft. A typical example is disclosed in Japanese Patent No. 2721950. This means that the center of the tunnel is located below the tunnel section or below the tunnel section, and the injection pipe is inserted radially upward from inside the tunnel, outside the top of the tunnel and outside the mirror. One area is reinforced by grouting.

[0005]

However, according to this method, the distance between the shaft and the improved part is extremely long, as is apparent from the typical example shown in FIG. However, the length of the hole for inserting the injection pipe becomes long, and the construction speed is reduced. Further, when the hole is bent at the time of drilling, the interval between adjacent injection pipes is not as designed, and an unimproved region may even be generated.

Further, all the injection pipes are upwardly injected, and a special setup for the upward injection is required, which also lowers the work efficiency.

Accordingly, an object of the present invention is to improve the construction efficiency and to reliably improve and reinforce a target location.

[0008]

According to a first aspect of the present invention, there is provided a method for manufacturing a vehicle, comprising the steps of: (a) forming a tunnel above a tunnel to be excavated and substantially on a vertical center line of the section; Digging an advanced shaft outside the section of the tunnel, inserting a straight injection pipe from inside the advanced shaft into the upper region of the tunnel section on both sides sandwiching the vertical center line, and grouting through the injection pipe. This is a grout injection reinforcement method in tunnel excavation characterized by injecting and reinforcing a target area.

According to a second aspect of the present invention, there is provided a grouting reinforcement method for tunnel excavation according to the first aspect, in which an injection pipe is inserted at a plurality of locations on one side of the cross section of the main tunnel to reinforce it by grouting. It is.

According to a third aspect of the present invention, injecting pipes are inserted at a plurality of locations on one side of the tunnel in an upper section of one cross section, and the inserting direction of each of the injecting pipes is horizontal or downward. A grout injection reinforcement method in tunnel excavation according to claim 1.

According to a fourth aspect of the present invention, there is provided a method for reinforcing grout in a tunnel excavation according to the first aspect of the present invention, wherein a substantially fan-shaped cross section is provided in the upper region of the cross section of the main tunnel on both sides of the vertical center line. It is.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the embodiments shown in the drawings.

Reference numeral 1 denotes a main tunnel (main shaft) to be excavated, which is an advanced shaft 2 having a center O outside the cross section of the main tunnel 1 above the cross section and substantially on the vertical center line CL of the cross section.
Dig in advance.

From the inside of the advanced shaft 2, a straight injection pipe 10
Are respectively inserted into the upper region of the cross section of the main tunnel 1 on both sides of the vertical center line CL. When the injection pipe 10 is inserted, in the case of the casing digging type, the casing is dug, and after inserting the injection pipe 10 therein, the casing is pulled out. When rod injection is performed, holes can be drilled with the rod to use the rod as an injection tube.
In order to insert the injection pipe from inside the advanced shaft 2, a small drilling machine may be selected and brought into the advanced shaft 2.

[0015] A plurality of injection pipes 10, 10 pre-installed
.. Or grout is injected through an injection pipe 10 which is erected sequentially to reinforce the target area.

After completion of the reinforcement, the tunnel 1 is excavated thereafter.

As is particularly clearly shown in FIG. 1, the injection pipe 10 is inserted at a plurality of locations in the upper region of one section of the tunnel 1 without depending on one injection pipe per one side, and is reinforced by grout injection. Is preferable in order not to leave an unimproved region.

In the present invention, from the positional relationship of the advanced shaft 2 with respect to the main tunnel 1, preferably, when the injection pipe 10 is inserted at a plurality of locations per one side in the upper region of one cross section of the main tunnel 1, The insertion direction of the injection tube 10 can be horizontal or downward. Therefore, it is not necessary to perform an upward injection.

The range of improvement is that the main tunnels 1 on both sides of the vertical center line CL are located outside the top end and outside the mirror surface of the tunnel.
In the region above the cross section, a substantially fan-shaped cross section can be set as the improvement range Z.

In the present invention, the present invention is not limited to the injection method and the injection tube type, or the grout material.

[0021]

As described above, according to the present invention, the construction efficiency can be improved and the target portion can be surely improved and reinforced.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a relationship between an advanced shaft and a cross section of the tunnel.

FIG. 2 is a schematic longitudinal sectional view showing a relationship between an advanced shaft and a section of the tunnel.

[Explanation of symbols]

 1 ... this tunnel, 2 ... advanced shaft, 10 ... injection pipe.

Claims (4)

[Claims] An excavation is performed on an advanced shaft above the cross section of the tunnel to be excavated and substantially on the vertical center line of the cross section, and the center is outside the cross section of the tunnel. Grout injection in tunnel excavation, wherein grout is injected through the injection pipe to reinforce a target area, by inserting respective injection pipes into upper regions of the cross section of the tunnel on both sides of the vertical center line. Construction method. 2. The grouting reinforcement method in tunnel excavation according to claim 1, wherein a plurality of injection pipes are inserted at a plurality of locations on one side of the tunnel in the cross section to reinforce the grout by grouting. 3. The injection pipe according to claim 1, wherein injection pipes are inserted at a plurality of locations on one side of the tunnel in one section, and the insertion direction of each injection pipe is horizontal or downward, and reinforcement is performed by grout injection. Grout injection reinforcement method in tunnel excavation. 4. The grout injection reinforcement method in tunnel excavation according to claim 1, wherein a substantially fan-shaped cross section is improved in an upper region of the cross section of the main tunnel on both sides of the vertical center line.