JPH02217596A - Segment joint structure - Google Patents

Abstract

PURPOSE:To simplify the structure of joint by providing the first segment incorporated with a joint box to be slid in the axial direction, the second segment to be connected with the joint box, and a flexible packing to be jointed circumferentially. CONSTITUTION:In a flexible segment 1, a steel segment is fabricated into an arc-shaped plate form from a steel bottom plate and side plates, in which a recession 5 extending toward the circumferential both ends is formed on the axial joint face 1a and the both ends are opened toward the circumferential joint face 1b. An arc-shaped plate joint box 7 is housed in the recession 5 and connected to the joint face 2a of usual segment 2. A packing 3 is bonded to the whole face of each axial joint face 1a of a ring-shaped flexible segment 1 and the portion 3b between the joint box 7 and the joint face 2a of the segment 2 is clamped with bolts 11. The joint face can have a water-stopping effect.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a segment joint structure in a shield tunnel, and particularly to a segment joint structure adapted to absorb deformation in the axial direction of the tunnel.

"Conventional technology" In general, in locations where there is a possibility that the deformation of the ground during the primary lining of shield construction will be larger than the predicted amount of deformation of the shield tunnel, the joint structure of the segments can absorb the deformation of the ground. A similar structure is adopted. The following two methods are conventionally known as such segment joint structures.

One type of joint is a so-called spring type joint, in which a compressed ring-shaped rubber gasket is set on the axial joint surface of each segment assembled in the circumferential direction, and deformation of the ground is absorbed by the return of the compressed rubber gasket. be. Another type of joint is a so-called slide type joint in which a joint member that is slidable in the axial direction is provided on the joint side of the segment, and the axial segment is connected to this joint.

"Problems to be Solved by the Invention" However, the above two conventional systems have the following problems to be solved.

In other words, the former spring type joint has a relatively small deformation absorption capacity per location, and therefore requires the installation of multiple ring-shaped rubber gaskets in the tunnel axis direction, which increases construction costs. The latter slide type joint, like the cover-resistant one-way type, has a complicated joint structure and is expensive per piece, and the same problem as above is that the construction cost is high.

This invention was made in view of the above circumstances, and can effectively cope with ground deformation during shield construction, and
The purpose of the present invention is to provide a segment joint structure that has a simple structure and can reduce costs.

"Means for Solving the Problems" A segment joint structure according to the present invention includes a first segment that incorporates a joint box that is slidable in the axial direction, a second segment that is connected to the joint box, and a second segment that is connected to the joint box in the circumferential direction. a flexible packing attached to the entire joint surface of the first segment to be joined to the first segment; the packing has both ends tightly connected to the first segment; The structure is such that the part sandwiched between the joint boxes is tightly connected to both sides.

"Operation" According to the present invention, the ground deformation that occurs during the primary covering and construction of the shield work is absorbed by the joint box built into the first segment sliding in the tunnel axis direction. At that time, the first segment and the second segment are separated from each other, but the seal attached to the joint surface of the first segment expands following the sliding of the joint box, so that the water stop effect on the joint surface is maintained. Demonstrated.

Embodiment FIGS. 1 to 4 show an embodiment of the present invention. In these figures, numeral 1 is a flexible segment (first segment), numeral 2 is a normal segment (second segment), and numeral 3 is a packing;
3 to 3 mainly constitute the segment joint structure according to the present invention.

As shown in Fig. 1, the flexible segment (first segment) 1 is a steel segment constructed by assembling a steel bottom plate and side plates so that the whole forms an arcuate plate shape, and has an axial joint. A recess 5 extending to both ends in the circumferential direction is formed in the surface 1a by the recess forming plate 4, and both ends of the recess 5 are open to the circumferential joint surface 1b. Circumferential joint hole holes 6 are bored at equal pitches in the circumferential joint surface 1b.

The recess 5 accommodates an arc-shaped joint box 7 having a shape that follows the inner surface of the recess 5 . This joint box 7 is connected to a joint surface 2a of a normal segment (second segment; hereinafter referred to as segment) 2, and has an upper plate portion of the joint box 7 and a corresponding upper plate of the recess forming plate 4. A hand hole 8 for working on the inner surface is passed through the part.

The packing 3 is a ring-shaped piece of flexible elastic rubber with excellent elasticity, and as shown in FIG. 2, each of the flexible segments 1 assembled in the circumferential direction It is attached over the entire surface of the axial joint surface 1a. Then, as shown in FIG.
A is fastened to the joint surface 1a by a rectangular bran iron plate 9 and a port 10 which are curved in the circumferential direction. Patsukin 3
A portion 3b sandwiched between the joint box 7 and the joint surface 2a of the segment 2 is tightly connected to both by a port 11.

The segments having the structure described above are assembled and constructed as follows.

(1) Assemble the flexible segment 1 in the same way as normal segment assembly.

(2) After assembling the flexible segment 1, attach the packing 3 to the flexible segment 1 in a ring shape.

(3) While assembling segment 2, port up joint box 7, packing 3, and segment 2 onto flexible segment 1.

During use, (4) Loosen the temporary fixing bolt 12 (see Figure 3) that fastens the flexible segment 1 and the joint box 7 together through the hand hole 8, so that the joint box 7 can move in the tunnel axis direction. Make it. Note that depending on the size of the temporary bolt 12 and the bolt hole 12a, the joint bolt and the slot of the two
A limit can be added to the amount of id.

According to this embodiment, the following excellent effects are exhibited.

■ When constructing a shield tunnel, if there is a possibility that the ground deformation during the first lining exceeds the predicted amount of deformation of the shield tunnel, this deformation can be effectively suppressed by sliding the joint box 7 in the direction of the tunnel axis. can be absorbed into Therefore, the flexible segment 1 can be suitably used in locations where ground deformation as described above is likely to occur.

■ The sliding amount of the m-hand box 7 is small compared to the size of the joint box 7, and most of the joint box 7 is accommodated in the recess 5 of the flexible segment 1, so the joint structure Rigidity can be maintained approximately constant at all times.

(2) Since the flexible packing 3 expands in accordance with the movement of the joint box 7, the clean water effect on the joint surface between the flexible segments 1 and 2 is fully exhibited.

■ The flexible segment 1 that achieves the above-mentioned effects has a very simple structure that only includes the joint box 7 and the packing 3, so its manufacturing cost is low, and it can be used normally. By joining these segments, an excellent joint structure as described above can be obtained, which can significantly shorten the construction period and construction cost required for constructing a shield tunnel.

5 to 8 each show an example of use of the segment joint structure of the above embodiment.

FIG. 5 shows an example of use in a reclaimed area. When constructing a shield tunnel T that passes from an underground structure 21 to a ground improvement area 22 underground in a reclaimed land 20, ground deformation occurs during the next lining. Flexible segments 1 are provided between the segments 2 at locations where the deformation of the ground is likely to occur, that is, near the underground structure 21, near the shaft 23, and near the ground improvement area 22, so as to absorb ground deformation.

Figures 6 and 7 show examples of use in road construction areas and river management areas, respectively. Ground deformation when constructing the shield tunnel T under the m road 30, respectively.
This corresponds to the ground deformation near the shaft 32 when constructing the shield tunnel T under the river 31.

FIG. 8 shows an example of use in soft ground, in which when constructing a shield tunnel T in soft ground 40, flexible segments are used in the part 42 that collides with hard ground 41 (where the ground changes suddenly). In addition, the flexible segments 1 are also used at locations 43 that receive secondary stress due to other underground structures, to cope with ground deformation that occurs during secondary lining.

"Effects of the Invention" As explained in detail above, according to the present invention, a first segment incorporating an axially slidable joint box, a second segment connected to the joint box, and a circumferential A flexible packing is attached to the entire joint surface of the first segment to be joined in the direction, and the packing has a peripheral portion tightly connected to the first segment, and a flexible packing attached to the entire joint surface of the first segment to be joined in the direction Since the part sandwiched between the segment and the joint box is configured to be tightly connected to both, it is possible to create a simple joint structure that can effectively and reliably cope with the ground deformation that tends to occur during tunnel construction. By the action of the flexible packing, the clean water effect on the joint surfaces of the segments can be exerted in t minutes. This brings about the excellent effect that a segment joint structure with excellent reliability and durability can be provided at low cost.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the present invention.
The first part is a perspective view of the flexible segment which is the main part of the segment's grip structure, Figure 2 is a perspective view showing the state in which flexible chamois are joined in the circumferential direction, Figure 3 and Fourth
The figure is a sectional view showing the Φ action of the segment joint structure, Figures 6 to 8 are diagrams each showing specific application examples of the segment joint structure, and No. 9 is an enlarged view of circle I at the 8th deviation. be. l...Flexible segment (first segment)
, la... joint surface, 2... segment (second segment), 3...
・・・・・・Parts skin, 7・・・・Joint box.

Claims (1)

[Claims] A first segment that incorporates a joint box that is slidable in the axial direction, a second segment that is connected to the joint box, and a flexible structure that is attached to the entire joint surface of the first segment that is joined in the circumferential direction. A packing having a segment characterized in that a peripheral portion of the packing is tightly connected to the first segment, and a portion sandwiched between the second segment and the joint box is tightly connected to both. Joint structure.