JP2618180B2 - Shield method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield method for constructing a sewer.

[0002]

2. Description of the Related Art Conventionally, when constructing a sewer by a shield method, a method of sequentially assembling divided segments or forming a segment at a face has been used.

[0003]

The conventional work of assembling a split type segment requires a lot of man-hours, and the method of forming a segment with a face is a reaction force at the time of shield excavation. There is a drawback that it takes a long time for the occurrence of.

SUMMARY OF THE INVENTION An object of the present invention is to provide a shield method in which a ground G is preliminarily improved with a chemical solution or the like to stabilize the ground, thereby performing lining without using segments.

[0005]

According to the construction method of the present invention, a plurality of chemical injection pipes are extruded into a ground at a front part of an outer periphery of a shield machine, and a chemical is injected to a predetermined area larger than at least the outer diameter of the shield machine. Improve the ground to obtain strength and work as a shoring (also serves as a shoring). It is characterized by:

The required strength of the ground improvement is preferably such that the sewer is held until the installation of the lining form, which also serves as a support, is completed.

[0007]

According to the construction method of the present invention, the ground can be improved by excavating the ground and the excavated portion can be covered without using segments.

That is, according to the shield method of the present invention, the ground is improved so that the required strength is obtained within a predetermined range larger than the outer diameter of the shield machine, and the reaction force is obtained by the lining form installed immediately after the tunnel construction. It excavates and forms a tunnel (excavation). In other words, in the shield method of the present invention, underground stabilization is performed by soil improvement by injecting a chemical solution, and a lining form installed immediately after tunnel construction is used as a means for obtaining a reaction force required for excavation. It is.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

First, as shown in FIG. 1 and FIG. 2, a plurality (7 in the illustrated example) is
The chemical injection pipe 2 of the present invention is moved to a position where the pitch circle 3 is larger than the outer diameter D of the shield machine 1 and the ground improvement portion is continuously stabilized by excavation of the shield machine to stabilize the ground. Extrude evenly.

Next, a chemical solution is injected while pulling the injection tube 2 into the shield machine 1, and the column-shaped improved portion 4 indicated by oblique lines is improved to a required strength. The improved portion 4 is arranged so as to cover a range larger than the outer diameter D of the shield machine 1 as a whole. In addition, the required strength of the improved portion 4 is set to a strength sufficient to maintain the shape of the tunnel T until the installation work of the lining form described later, which also acts as a support (also serves as a support), is completed. Has been taken.

Next, the improved portion 4 is dug by the shield machine 1 by applying a reaction force to the lining form in a manner described later.

Therefore, when the improved excavation section 5 formed by excavating the improved section 4 reaches the rear of the shield machine 1, the lining form serving also as a support is moved, installed and fixed, and immediately laid. I do.

FIG. 3 shows one mode of how to receive a reaction force during excavation of the shield machine. In this embodiment, the rear end of the shield jack 10 is brought into contact with the front surface of the formwork frame 12 of the lining formwork 11 for constructing the lining concrete layer 8A on the inner periphery of the ground improvement section 5 to reduce the reaction force. receive.

[0015]

As described above, according to the present invention, the ground is improved by injecting a chemical solution, the ground is excavated, the excavation is performed without using the conventional segment, and the lining is performed immediately after the excavation, so that the work can be performed. The man-hour can be saved, and the working time can be shortened.

[Brief description of the drawings]

FIG. 1 is a side cross-sectional view illustrating an improved part forming mode according to an embodiment of the present invention.

FIG. 2 is a front view of FIG. 1;

FIG. 3 is a side sectional view showing one mode of a reaction force receiver.

[Explanation of symbols]

 D: Outer diameter of shield machine G: Ground T: Tunnel 1: Shield machine 2: Chemical injection tube 3: Pitch circle 4: Improvement unit 5: Improvement Excavated part 8a ・ ・ ・ Concrete layer 10 ・ ・ ・ Shield jack 11 ・ ・ ・ Form for secondary lining 12 ・ ・ ・ Frame for form

Claims (1)

(57) [Claims] 1. A plurality of chemical liquid injection pipes are extruded into a ground at a front part of an outer periphery of a shield machine, and a chemical liquid is injected to improve a ground to obtain a required strength at least within a predetermined range larger than the outer diameter of the shield machine. A shield method comprising excavating by taking a reaction force on a lining formwork that also acts as an excavator, and lining the excavated and improved portion of the ground after excavation.