JPS6088794A - Enlarging shield construction method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an expanding shield method for enlarging the diameter of a cut tunnel during excavation by a shield machine.

In the conventional shield construction method, the diameter of the cut tunnel may be expanded during excavation. Conventionally, in such cases, once the entire length has been excavated with a shield machine, only the areas to be enlarged are excavated using a plain excavation machine, which is a troublesome and dangerous work. The invention was made to solve the above-mentioned problems, and the purpose is to provide an expanding shield method that allows the diameter of a cut tunnel to be easily and safely expanded during excavation by a shield machine. do.

Structure of the Invention The expanding shield construction method according to the present invention involves cutting and excavating the ground larger than the outer diameter of the shield machine in front of the shield machine, and filling a bearing bag attached to the outer periphery of the shield machine with sand, etc. The earth pressure is temporarily supported by the shield machine, and the segments are assembled at the rear of the shield machine.As the shield machine moves forward, the outer periphery of each segment is The above objective is achieved by expanding the segment so as to come into contact with the ground and fitting a new segment into the gap created between the segments.

EXAMPLES Hereinafter, the present invention will be explained in detail based on examples shown in the drawings.

In the figure, 1 is a shield machine, and 2 is a segment assembled at the rear of the shield machine 1.

As the segment 2, for example, the knuckle joint type that can be expanded as shown in FIGS. A recess 2b is formed and the connection is completed by fitting the two.

When the shield machine 1 reaches a position where the diameter of the cutting tunnel is expanded during excavation, the ground is cut to a size larger than the outer diameter of the shield machine 1. It is conceivable to cut the ground by attaching an overcutter 3 to the front of the shield machine 1, but it is also conceivable to excavate by spouting jet water around the cutter's periphery.

A pressure-bearing bag 4 is placed on the outer periphery of the shield machine 1.

The pressure-bearing bag 4 has a storage part 5 installed inside the shield machine 1, and an openable case 5a that is flush with the skin plate 1a of the shield machine 1 is attached to the storage part 5, and the case 5a is opened. A bearing bag 4 is positioned between the outer periphery of the shield machine 1 and the ground.

In the embodiment, a double rubber bag is used as the pressure-bearing bag 4. This pressure-bearing bag 4 is filled with air and inflated in the gap between the cut tunnel earth excavated to a size larger than the outer diameter of the shield machine 1 and the outer periphery of the shield machine 1 to temporarily support the earth. Thereafter, the bearing bag 4 is filled with sand or the like to temporarily support the ground.

The pressure-bearing bag 4 is left behind as the shield machine 1 moves forward. After the rear end of the shielding machine 1 has passed, the pressure-bearing bag 4 is positioned on the outer periphery of the segment 2 assembled at the rear of the shielding machine 1.

The outer periphery of the segment 2 is expanded so that it comes into contact with the ground while removing sand and the like from the pressure-bearing bag 4. For example, a stand 6 for the reaction force receiver is placed in the assembled segment 2, and the reaction force receiver expands the segment 2 by means of a jack 7 attached to the stand 6.

When the segment 2 is enlarged, a part of the segment 2 is cut off and a gap is created, and a new segment 2' is fitted into the gap. The segments 2' may be of a knuckle joint type as shown in FIG. 8, or may be of a type in which a plug 2C is inserted after fitting as shown in FIG. 9.

Before segment 2 is expanded, there is a gap between segments 2 and 2 as shown in Figure 2, but after expansion, the gap between segments 2 and 2 is closed as shown in Figure 3. .

It is conceivable that the shield tunneling machine 1 assembles a truss within the expanded segment 2 and moves forward by taking a reaction force from the truss.

Effects of the Invention The present invention has the above-described configuration, and it is possible to enlarge the diameter of a cut tunnel during excavation by a shield machine very easily and safely.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of the construction state of this invention, Figures 2 and 3 are front views of the joint portion of the segment, and Figure 4 is
-■ Line sectional view, Figure 5 is ■-V line sectional view, Figure 6 is V+
-Vt line sectional view, FIG. 7 is a vertical sectional view of the storage portion, and FIGS. 8 and 9 are horizontal sectional views of the fitted segments. 1...Shield machine, 2...Segment, 3...Cutter, 4...Pressure bag, 5...Storage section, 6...Reaction force receiver is stand, 7
・Jyatsuki. A2 1 Figure, trial) i 2 1:;ヱ1 31shi1] Figure 5 Figure 6 Figure 7 Figure 8 Figure 91;'m+

Claims (1)

[Claims] At the front of the shield machine, excavate the ground by cutting the ground larger than the outside diameter of the shield machine, fill the pressure bag attached to the outer circumference of the shield machine with sand, etc. to temporarily support the tonosho, and then remove the ground behind the shield machine. Assemble the segments, and as the shield machine moves forward, while removing sand etc. from the bearing bag left behind, expand the outer circumference of each segment so that it touches the ground, and fill the gap created between the segments with a new one. Expanded shield construction method characterized by fitting segments.