JPS59102091A - Drilling and enlarging of tunnel - 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 The present invention relates to a method for enlarging and excavating an already excavated normal diameter tunnel for external use, and in particular, a method for enlarging and excavating a tunnel at will by varying the diameter of the enlarged excavation or making it eccentric. It is related to construction methods.

The shield method is often used as an excellent construction method for tunnel excavation for subway construction and underground cable burying work, but when building subway stations or connecting underground cables, it is often necessary to use the shield method. It becomes necessary to enlarge the section. The conventional construction method for carrying out the above expansion work is as follows:
For example, there are methods to expand excavation by digging a vertical shaft from the ground for each area scheduled for expansion, or by cutting a normal diameter tunnel and adding an enlarged blade to the cutter head of a shield machine when the area is reached. It was five.

However, in recent years, the former has become increasingly difficult to implement due to restrictions on above-ground and underground structures, especially in urban areas, and the shafts that have been excavated have also had to be backfilled, with the exception of some areas during expansion work. There was also a cost problem.

In addition, the latter has limitations on the excavation diameter because as the expanded excavation diameter increases, it becomes difficult to resist the earth pressure from the surrounding surface.
This method has disadvantages such as not being able to carry out the excavation work of the normal diameter tunnel and the enlarged tunnel in parallel, and also having to attach and detach the S degree enlarged blade, which reduces the work efficiency of the normal diameter tunnel excavation. Ta.

Therefore, the applicant of the present application has previously proposed a tunnel expansion excavation method that improves the above-mentioned conventional construction method. This new construction method involves excavating a normal-diameter tunnel using a secondary shield machine, then removing a segment at one end of the area scheduled for expansion, enlarging the excavation, constructing a launch base, and then assembling and installing it at the launch base. A construction method in which an enlarged shield machine is propelled in the axial direction along the outer periphery of a normal diameter tunnel, and the enlarged section is constructed by removing some segments and attaching secondary segments to the enlarged excavation section while widening the section. It is.

Therefore, the present application proposes an enlarged tunnel excavation method suitable for carrying out enlarged excavation within a relatively short range in the axial direction, such as the above-mentioned starting base, and the gist of the present application is as follows.

This is a construction method in which some segments of the area to be expanded, which are set up in a normal tunnel, are sequentially removed and the outer circumference is enlarged and excavated. The proximal end side of a circumferential shield machine that excavates along the outer periphery of the tunnel is rotatably supported by a guide ring, and this guide ring is formed to have a smaller diameter than the second segment and is installed in the normal diameter tunnel, When enlarging excavation concentrically with a normal diameter tunnel, the center of the guide ring should be aligned with the center of the normal diameter tunnel, and when enlarging the enlarged part PJIJ in an eccentric manner, the center of the guide ring should be eccentric. A tunnel expansion excavation method characterized in that guide links are attached to some segments at both ends of an area to be expanded, and expansion excavation can be performed in an appropriate concentric or eccentric manner by changing the attachment position of the guide links.

As a result, there is no need to provide a vertical shaft when carrying out enlarged excavation, and enlarged excavation can be carried out efficiently in the area to be enlarged by parallel work with normal diameter tunnel excavation. In particular, by changing the mounting position of the guide ring that guides the proximal end of the circumferential shield machine, it is possible to carry out any enlarged excavation concentrically or eccentrically with the normal diameter tunnel. This is a tunnel expansion excavation method.

Examples of the construction method of the present invention will be described below with reference to the drawings.

First, as shown in FIGS. 1 and 2, among the partial segments 3 in the area 2 to be expanded, which are provided on the outer periphery of the normal diameter tunnel 1, the lower partial segment 3a is removed.
Guide rings 5 and 6 are respectively attached to the inner surface of the partial segment 4 adjacent to the partial segment 3 in the area to be expanded.

The guide rings 5 and 6 are formed by integrally joining valley guide ring pieces divided into circular arcs with valleys having a U-shaped cross section, and have a diameter smaller than the inner diameter of the tunnel 1 with a normal diameter at least. The center 02 of the cylinder 5°6 is located eccentrically from the center 01 of the normal diameter tunnel 1.

Each of the guide rings 5 and 6 is rotatably mounted on the proximal end side of the circumferential shield machine 7, respectively.

Although detailed illustrations of the circumferential shield machine 7 are omitted, similar to general shield machines, a cutting edge is formed at the tip of the propulsion side, a propulsion jack is built in, and the cross section has an arc shape on the outer circumferential side. It is roughly U-shaped. These guide rings6.
The circumferential shielding machine 7, which is rotatably supported on the proximal side by the circumferential shield machine 7, is installed by locally excavating the ground below the removed partial segment 3a, and A reaction force receiving plate 8 is attached to the ground surface on the opposite side to the direction in which the shield machine 7 is propelled.

Next, when enlarging excavation by propelling the circumferential shield machine 7 in the direction of the arrow, first remove some segments (3b) in front and apply a reaction force to the propulsion gloss built in the circumferential shield machine (not shown). The receiving plate 8 is extended as a reaction force receiver, and the cutting edge part is pushed into the ground in front, and the machine moves forward to excavate the earth and sand inside the circumferential shield machine.

A circumferential segment 9 having an arcuate outer circumferential side and a U-shaped cross section is installed in the rear enlarged portion caused by the excavation of the circumferential shielding machine 7, and the circumferential segment 9 has an arcuate outer circumferential side and a U-shaped cross section, similar to the circumferential shielding machine. As shown in FIG. 3, a valley piece material 10.10 is placed between the segment 9 and a portion of the segment 4 adjacent to the planned expansion area 2.
After inserting the next segment 4 and the piece material 10
and the circumferential segment 9 are bolted together.

In the subsequent enlarged excavation, the reaction force is sequentially received by the newly installed circumferential segments 9 in place of the reaction force receiving plate 8, and each of the guide rings 5, 6 is sequentially removed while some segments 3 on the propulsion side are sequentially removed as before. The circumferential shield machine 7 is guided along the outer periphery of the normal diameter tunnel 1, and the desired enlarged excavation is performed over the entire circumference.

Through this enlarged excavation, the periphery is earth-retained with circumferential segments 9 as shown in FIGS. 4 and 5, and an enlarged tunnel 11 eccentric to the normal diameter tunnel 1 is constructed.

That is, by installing the guide rings 5 and 6 with their centers 02 shifted upwards from the center 01 of the normal diameter tunnel 1, the enlarged excavation by an eccentric circle in which the upper enlarged excavation part is large and the lower enlarged excavation part is small. has been done.

Therefore, by appropriately changing the center of the guide ring with respect to the center of the normal diameter tunnel, it is possible to perform enlarged excavation with any eccentric circle.

Next, FIG. 6 shows another embodiment of the present application, and for ease of understanding, the same members as in the previous embodiment are indicated by the same reference numerals. In this embodiment, a plurality of cylinders 12, 13 are attached to the outer periphery of each guide ring 5, 6.
Each guide ring is partially fixed to the segment 4 via 2.13.

That is, by expanding and contracting the valley cylinders 12 and 13 to an arbitrary length, it is possible to appropriately change the center of the guide rings 5 and 6 with respect to the center of the normal diameter tunnel 1.
Eccentric circles and concentric circles can be easily enlarged and excavated.

In the tunnel expansion excavation method of the present application, a guide ring that guides a circumferential shield machine that is propelled along the circumference is formed smaller than the inner diameter of the normal diameter tunnel and installed inside the normal diameter tunnel. However, with this, arbitrary enlarged excavation can be performed.

In the above embodiment, concentric circles and eccentric circles were illustrated, but
By changing the shape of the guide ring, it is also possible to perform concentrically or eccentrically expanded elliptical excavation 9 or rectangular expanded excavation with gentle arcs at the four corners.

[Brief explanation of the drawing]

Figure 1 and Figure 3 are process explanatory diagrams showing the excavation method of the present application, Figure 2 is a sectional view taken along the line ■-■ in Figure 1, Figure 4 is an end view of the enlarged tunnel in the completed state, and Figure 5 is the 6 is a sectional view similar to FIG. 2 according to another embodiment. [Explanation of symbols] 1...Normal diameter tunnel 2...Expansion planned area3.
4...-Next segment 5, 6...Guide ring 7.
... Circumference shield machine 8 ... Reaction force receiving plate 9 ... Circumferential segment 10 ... Piece material 11 ... Expanding tunnel 12.13 ... Cylinder 01 ... Center of normal diameter tunnel 02. ...Main patent applicant for guide rings Mitsui Construction Co., Ltd.

Claims (1)

[Claims] This is a construction method in which the primary segments of the area to be expanded, which are usually installed in a tunnel, are removed one by one and the outer circumference is enlarged and excavated, and the outer circumference of the normal diameter tunnel is excavated using a built-in propulsion jack with a cutting edge formed on the propulsion tip side. The proximal end side of the circumferential shield machine that excavates along When enlarging and excavating concentrically with a normal diameter tunnel, align the center of the guide link with the center of the normal diameter tunnel, and when enlarging and excavating eccentrically, set the center of the guide ring eccentrically, respectively. A tunnel expansion excavation method characterized in that the guide links are attached to the primary segments at both ends of the planned area, and expansion excavation can be performed in an appropriate concentric or eccentric manner by changing the attachment position of the guide links.