JPS6229598B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for constructing a tunnel widening section and a segment used in the construction.

For example, one method of distributing power through high-voltage wires is to route power through a power transmission cable in a tunnel provided underground. Incidentally, since the cross section of the joint portion of this cable is larger than the cross section of other cable portions, the portion of the tunnel where the cable joint portions are concentrated is a widened portion with a wide space. Construction of this widening section often involved constructing a vertical shaft from ground level and then cutting and widening the tunnel to secure the space. However, according to this construction method, the construction of a shaft is severely restricted by ground conditions, such as route conditions and work environment, and in some cases, it has been impossible to construct a shaft.

The purpose of the present invention is to enable construction of widening sections without being influenced by ground conditions,
Another purpose is to facilitate construction work.

Examples of the present invention will be described below.

In FIG. 1, a tube body 1 is arranged on the inner peripheral surface of a tunnel constructed underground by a method such as a shield method, and this tube body has a plurality of segments 2...
It is composed of a combination of... Inside tube body 1,
A plurality of power transmission cables (not shown) are inserted through the tubular body 1, and widened portions 3 for housing the cable joints are provided in the pipe body 1 at locations where the joints of the cables are concentrated.

This widened portion 3 is provided over a certain section d in the axial direction of the tube body 1, and as shown in FIGS. 1 and 2, the width of the tube body is widened on both sides, and the cross section is non-circular. It is oval in shape. In the illustrated example, the widened portion 3 includes six segments 4 arranged almost symmetrically,
5, 6, 7, 8, and 9, and reinforcing members 10 and 10a are disposed facing each other in the center of the peripheral wall. One reinforcing member 10 is held between segments 4 and 9, and the other reinforcing member 10a is held between segments 6 and 7, respectively. Each segment can be a steel segment, a synthetic segment, a concrete segment, etc., and in this example, a steel segment is used. Segments 4 and 6 are attached to plate 4a as shown in FIGS.
One end side of the reinforcing members 10 and 6a extends outward from the ribs 4b and 6b to form cover parts 4c and 6c, and both cover parts 4c and 6c cover the outer surfaces of the reinforcing members 10 and 10a. Further, the inner circumferential surface of the widened portion 3 forms a concrete layer 11 to integrate the inside. In addition, on the outer periphery of the tube body 1 at both ends of the widened portion 3, a plurality of fan-shaped end plates 12 are provided in order to strengthen the surrounding ground.
... is pushed out into the ground from the peripheral wall of the widening section. The end plate 12 is inserted so as to be extrudable between the opposing end faces of the segments. In addition, if the ground is sandy soil, it is preferable to strengthen the ground by injecting chemical liquid instead of using gables. Chemical solution injection parts 15, 15 are installed at both ends of the construction section d of the widened part in place of the end plate.
(Fig. 1) may be provided.

Next, the construction method will be explained.

Before the construction of the widened section shown in FIG. 4, the segments 4 to 9 of the pipe body 1a in the construction section d are assembled as follows.
It is different from that of the tube segment. That is, the segments 4 located above and below the peripheral wall of the tube body 1a
and 9, segments 6 and 7 (FIG. 5) join each other in the center of the tube. In this state, construction section d
At both ends of the pipe body, end plates 12 are pushed out and installed in advance into the ground outside from the inside of the pipe body. Pipe body 1a
They may be placed around the entire outer periphery, but they may also be placed only on the right half of the circumference, as shown in FIG. Therefore, among the segments 4, 5, and 6 on the right side, for example, parts of the plates 4a, 5a of the segments 4, 5 are removed to provide windows 4d, 5b, and through these windows,
The ground outside the pipe body 1a is excavated. After that, window 4d,
After sealing the tube 5b, a plurality of jacks 13 are installed horizontally as shown in FIG. 6, and both ends of the jacks 13 are brought into contact with the peripheral wall of the tube 1a. When the jack 13 is actuated in this state, the segments 4, 5, and 6 on the right side are pushed outward by a certain distance as shown in FIG. 7 because the resistance on the right side of the tubular body 1a is smaller than on the left side. At this time, gaps 14 and 1 are provided in opposing portions of segments 4 and 9, and 6 and 7, respectively.
4a is opened, but since the cover portions 4c and 6c cover the gap, earth and sand outside the tube body 1a will not enter the tube body. Similarly, after placing the end plate 12 on the left outer periphery of the pipe body, excavating the ground outside the left segments 7, 8, and 9 through the window, and then operating the jack 13... When the left segment is pushed outward, a widened portion 3 having an oval cross section is formed in the tube 1a as shown in FIG.
is formed. Then, the reinforcing members 10, 10a are filled between the gaps 14, 14a. Then, as shown in FIG. 9, the ends 12a (FIG. 8) of the end plates 12 protruding into the widened portion 3 are cut.
Then, a concrete layer 11 is formed on the inner peripheral surface, and construction is completed (Fig. 2).

In addition, the pipe body 1a in the construction section d of the widened part
The widened portion may be formed by extruding only one side of the tube, and it is not necessarily necessary to widen both sides of the tube, and the cross-sectional shape of the widened portion is not limited to an elliptical shape.
Furthermore, objects inserted into the tube are not limited to power transmission cables, but include various objects such as water and sewer pipes and telephone cables.

A widened section can be formed in a tunnel without being affected by various conditions on the ground. In addition, one segment that holds the reinforcing member has a cover on its one end side, which protects the reinforcing member and prevents earth and sand from falling into the tube, providing special protection and fall prevention during work. Since there is no need to assemble any additional members, construction can be carried out smoothly. Further, by adjusting the width of the gap formed by pushing the segments outward, the cross-sectional shape of the widened portion can be easily changed as desired.

[Brief explanation of the drawing]

Figure 1 is a plan view of the widened part, Figure 2 is Figure 1-
Line enlarged sectional view, Figure 3 is a sectional view of the segment,
4 is a plan view of the tube before construction of the widened portion, and FIGS. 5 to 9 are explanatory diagrams showing the construction of the widened portion step by step. 1...Pipe body, 1a...Pipe body in the widened part construction section, 2...Segment, 3... Widened part, 4, 5,
6, 7, 8, 9...segment, 4c, 6c...
Cover part, 4d, 5b... Window, 10, 10a...
Reinforcement member, 11... Concrete layer, 12... End plate, 12a... End part of end plate, 13... Jacket, 1
4, 14a... Gap section, d... Widening section construction section.

Claims (1)

[Claims] 1. A window is provided by removing a portion of the peripheral wall segment at the location where the cable joint portion of the pipe body consisting of a plurality of segments is housed, and the ground outside the peripheral wall is excavated through this window. A method for constructing a widening section of a tunnel, which comprises: extruding a circumferential wall corresponding to an excavated location outward; and then filling a gap in the circumferential wall formed by this extrusion with a reinforcing member. 2. At the location where the cable joint part of the pipe body consisting of multiple segments is housed, a window is provided by removing some of the segments of the surrounding wall, and the ground outside the surrounding wall is excavated through this window to accommodate the excavated location. A segment used for carrying out a method for constructing a widened part of a tunnel, which is characterized by extruding a circumferential wall outward, and then filling a reinforcing member into a gap in the circumferential wall formed by this extrusion, the segment comprising: 1. A segment for use in constructing a widened part of a tunnel, characterized in that one segment that holds the member has an extended cover part that can cover the outer surface of the reinforcing member at one end thereof.