JP3353203B2 - Joint structure of shield segment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint (so-called joint between rings) structure for joining shield segments between rings.

[0002]

2. Description of the Related Art Conventionally, there is a following main structure between rings. Bolt box type This is a type frequently used for RC segments. As shown in FIG. 14, a bolt box 52 is provided on the inner peripheral side of a segment 51 to be joined.

[0005] As shown in FIG. 15, a T-shaped groove 54 is provided at an end of a segment 51, and a cotter 55 whose both ends are swelled is driven into a groove 54 where segments are joined to join.

A one-touch type steel frame segment using a spring is used. As shown in FIG. 16, a convex metal piece 56 is protruded from one segment 51a, and a coil spring is attached to the other segment 51b. A pair of clamp hardware 57 to which a rotational force is applied is mounted, and the convex hardware 56 is forcibly inserted between the pair of clamp hardware 57, and the convex hardware 56 is clamped by these clamp hardware 57.
Sandwich.

[0005]

However, in the case of the bolt box type, the bolt box becomes expensive and is reflected in the segment cost. Also, since the inside of the bolt box becomes hollow, the cross section of the joint is lost. In addition, there is a problem that the bolt box needs to be filled for corrosion prevention.

The cotter joint type has poor workability in assembling, and the one-touch type using a spring has a complicated structure and can be applied only to a steel frame segment.

By the way, a key lock type segment (referred to as "KL segment") as disclosed in Japanese Patent No. 2727419 has already been provided as a shield segment in which stress concentration on fittings is reduced. ing. This is because the joint surfaces of the segments are flat surfaces, one joint surface has a concave portion for stress dispersion that is concavely formed in an arc shape and extends in the longitudinal direction of the joint surface, and the other joint surface has a concave portion for stress distribution. Each of the stress-dispersing convex portions that protrude in an arc shape with a small radius of curvature and similarly extend in the longitudinal direction is provided,
When these concave portions and convex portions are fitted to each other, a minute gap due to the difference in the radius of curvature is formed only inside the concave portions so that the concave portions and the convex portions come into curved surface contact, and a flat joint surface between the concave portions and the convex portions is formed. When a shear load greater than the design proof stress is applied to the joint hardware, the joint surfaces that are in plane contact with each other are minute when the joint portion between the concave portion and the convex portion comes into planar contact on both sides in the thickness direction. Plane sliding is allowed in the thickness direction by the gap.

In the example disclosed in this patent publication, a C-shaped bolt is used as a fitting, and a stress dispersing concave portion and a stress distributing convex portion are provided between the C-shaped bolt and a bolt insertion hole through which the C-bolt is inserted. By forming a gap that is larger than the minute gap between them, the stress dispersing action of these concave portions and convex portions is effectively performed.

However, the use of a C-shaped bolt as a fitting hardware not only impairs the workability of assembling the segments, but also has disadvantages in forming the segments.

When the joint between the rings in the KL segment as described above is observed, the stress in the cross-sectional direction of the tunnel is fit between the stress-dispersing concave portion and the stress-dispersing convex portion (with a slight gap left). ) Is enough to support
As for the strength of the joint hardware, it is sufficient if the joint hardware can withstand the axial tension that separates the segments in the tunnel axial direction. However, it is necessary that the joint metal has a structure capable of allowing displacement between the segments due to a slight gap between the stress dispersing concave portion and the stress dispersing convex portion.

It is an object of the present invention to provide a joint structure for a KL segment which not only satisfies such requirements but also allows one-touch segment assembly between rings.

[0012]

SUMMARY OF THE INVENTION The present invention relates to a shield segment joint structure in which segments are joined by a male joint provided on one segment and a female joint provided on the other segment. The joint surfaces between the rings are flat surfaces, one of the inter-ring joint surfaces has an arc-shaped concave portion for stress dispersion extending in the longitudinal direction of the inter-ring joint surface, and the other inter-ring joint surface has a stress dispersing portion. Each of the stress-dispersing convex portions, which protrude in an arc shape with a smaller radius of curvature than the concave portion and similarly extend in the longitudinal direction, is provided.When these concave portions and convex portions are fitted to each other, a minute gap due to a difference in the radius of curvature is reduced. The relationship between the concave portion and the convex portion formed only inside the concave portion so that the concave portion and the convex portion make a curved surface contact, and the flat inter-ring joint surface makes planar contact on both sides in the thickness direction of the fitting portion between the concave portion and the convex portion. did When male fitting has a two-stage head,
The part between them is the neck, and the two-stage head is projected from the inter-ring joint surface and buried in one segment, the female joint is in the recess formed in the inter-ring joint surface,
A frame plate for closing the opening surface of the recess, a fastening member for fastening the neck of the male joint, and an elastic member for biasing the fastening member are installed. An opening for receiving the two-stage head into the recess is provided, and the fastening member is prevented from falling out of the recess by the frame plate, and the sliding is guided by the frame plate, so that the elastic member biases the male joint. The neck is fitted and tightened. As a result, the extraction of the male joint from the female joint is prevented, and the segment is formed by the gap between the stress dispersing concave portion and the stress distributing convex portion. It is characterized in that mutual sliding in the thickness direction is allowed.

[0013]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

In FIG. 1, a flat ring-to-ring joint surface 3 between two segments 1 and 2 of an RC structure to be joined.
4, a stress dispersing concave portion 5 which is depressed in an arc shape and extends in the longitudinal direction and a stress dispersing convex portion 6 which protrudes in an arc shape and also extends in the longitudinal direction are formed.

The curved surface of the concave portion 5 has a radius of curvature of the convex portion 6 so that the concave portion 5 for stress distribution and the convex portion 6 for stress distribution have a small gap between the curved surfaces when they are fitted to each other. Is slightly larger than the radius of curvature of the curved surface, but the depth of the curved valley portion 5a of the concave portion 5 and the height of the curved surface top portion 6a of the convex portion 6 are equal, and the inter-ring joint surfaces 3.4 are brought into planar contact. At this time, the curved valley portion 5a of the concave portion 5 and the curved surface top portion 6a of the convex portion 6 make a curved surface contact with a required area. Normally, on both sides of the curved surface contact portion (in the thickness direction of the segments 1 and 2), only on the inside that does not exceed the range of the concave portion 5,
A minute gap 7 is formed.

Therefore, since the concave portion 5 and the convex portion 6 have different radii of curvature, they are slightly loosely fitted in the thickness direction of the segments 1 and 2, and the depth of the curved valley portion 5 a of the concave portion 5 and the convex portion are different. 6 is equal to the height of the curved surface top 6a, but since the concrete is compressible, the segments 1 and 2 can keep the gap 7 even when the flat ring-to-ring joint surfaces 3 and 4 maintain a planar contact state. That is, there is room for sliding in the thickness direction. For the shear stress in the thickness direction of the segment (the cross-sectional direction of the tunnel), the flat portions of the inter-ring joint surfaces 3 and 4 simply slide in parallel while being in plane contact. The top 6a of the curved surface of the projection 6 is
The sliding is performed while changing the curved surface in contact with the shallower surface, so that the stress is absorbed while being dispersed radially.

The shear stress in the thickness direction of the segments is handled by the joint formed by the arc-shaped concave portions 5 and the convex portions 6 formed on the joint surfaces 3 and 4 between the rings of the segments 1 and 2 as described above. However, the following fittings are used for the tension between the rings.

FIGS. 2 to 6 show a first example of such a case.
A male joint A is provided on one of the two, and a female joint B is provided on the other. In the illustrated example, the male joint A is provided on the segment 2 on which the convex portion 6 is formed, and the female joint B is provided on the segment 1 on which the concave portion 5 is formed, but may be reversed.

The male joint A is provided with two steps of circular heads 9 and 10 protruding from the inter-ring joint surface 4 on an embedding bolt 8 embedded in the segment 2 and a neck portion between the heads 9 and 10. The head 9 at the tip has a truncated cone at the tip to facilitate insertion into the female joint B.

The female joint B is embedded in the segment 1, that is, a frame 12 fitted in a rectangular recess 25 formed in the inter-ring joint surface 4, and a pair of tightening members mounted in the frame 12. 13 and 14 and elastic members 15 and 16 such as rubbers arranged in the frame 12 for urging the tightening members 13 and 14 respectively.

As is clear from FIGS. 2, 5 and 6, the frame 12 has four frame plates 17 and 18 made of steel.
・ It is box-shaped in 19 ・ 20, and the outer frame plate 1
7 closes the opening surface of the recess 25 and the outer surface is flush with the inter-ring joint surface 4. A circular opening 21 is provided at the center of the outer frame plate 17, and a circular opening 22 provided at the center of the inner frame 18 is formed from the opening 21.
Up to this point is a hole 23 that can receive the heads 9 and 10 of the male joint A.

The pair of fastening members 13 and 14 are also made of steel,
These are arranged on both sides of the hole 23 between the four frame plates 17, 18, 19, and 20, and
・ Sliders are slidable using 18, 19, and 20 as guides. On the opposing surfaces of the fastening members 13 and 14,
5 so that the neck 11 of the male joint A can be held together.
As shown in the figure, semicircular concave portions 13a and 14a are formed respectively. The peripheral portions of the recesses 13a and 14a are cut to facilitate the penetration of the head 9 of the male joint A.

The pair of elastic members 15 and 16 urge the pair of tightening members 13 and 14 toward the hole 23, respectively.
They are fixedly arranged between the frame plates 17, 18, 19, 20.

The joining of the segments 1 and 2 by the male joint A and the female joint B having such a structure is performed as follows (see FIGS. 2 to 4). When the heads 9 and 10 of the male joint A are inserted into the holes 23 through the openings 21 of the frame plate 17 on the outside of the female joint B, the head 9 at the distal end is turned into a pair of fastening members 13.
14 is pushed open over it to the opening 22 of the inner frame plate 18 and the other head 10 remains in the opening 21 of the outer frame plate 17. Since the pair of tightening members 13 and 14 are urged by the elastic members 15 and 16, the two members together clamp the neck 11 between the heads 9 and 10 of the male joint A, and thereafter, the male joint A Withdrawal from the female joint B is prevented, and the segment 1 and 2 resist pulling that separates the segments 1 and 2 in the tunnel axial direction. However, since the pair of fastening members 13 and 14 are urged by the elastic members 15 and 16, the gap 7 between the arc-shaped stress-dispersing concave portion 5 and the arc-shaped stress-dispersing convex portion 6 is equal to that of the gap 7. Sliding is acceptable.

FIGS. 7 to 12 show a second example of a joint structure using joint hardware. In this case, the male joint A is the same as above, but the structure of the female joint is different. This female joint C has a form in which only the outer frame plate 17 in the above-described example is fixed to the segment 1 with the anchor 24 shown in FIG. A pair of semi-cylindrical fastening members 26 and 27 and a ring-shaped elastic member 29 for urging them from the outer periphery are arranged.

A hole 30 having a length capable of receiving the head 9 and the neck 11 of the male joint A is provided between the pair of tightening members 26 and 27. Projections 26a and 27a that fit between the heads 9 and 10 are formed on the inner periphery of the fastening members 26 and 27. The elastic member 29
Grooves are formed on the outer periphery to enhance elasticity.

In the case of the joint structure of the second example, the heads 9 and 10 of the male joint A are connected to the female joint C as shown in FIGS.
A pair of tightening members 26.
27 into the hole 30 by the tip
Moves over the projections 26a and 27a so as to push open the pair of fastening members 26 and 27. And these protrusions 26
a and 27a fit between the heads 9 and 10, the pair of tightening members 26 and 27 clamp the neck 11, and the head 10 stays in the opening 21 of the frame plate 17, and thereafter, the male joint A is prevented from coming off from the female joint C.

FIGS. 13A, 13B and 13C show other cross-sectional shapes of the elastic member for urging the pair of tightening members 13 and 14 or 26 and 27, respectively.

[0029]

As described above, according to the joint structure of the present invention, the two-stage head of the male joint is simply inserted straight into the opening of the frame plate of the female joint, and the female joint is tightened. Since the member fits into the neck between the two heads of the male joint to prevent the male joint from being pulled out, the segment assembly between the rings can be easily performed with one touch.

In addition, the male joint and the female joint correspond to the tension between the segments, and the shearing is performed by fitting the arc-shaped stress-dispersing concave portion with the arc-shaped stress-dispersing convex portion having a smaller radius of curvature. The former joint, which responds to stress and is responsible for tension, has a simple structure that can easily displace the displacement required for dispersing the stress of the latter joint, which is responsible for shear stress, that is, the gap between the concave part for dispersion and the convex part for stress dispersion. Because it is acceptable, it is possible to make a shield tunnel structure with excellent earthquake resistance,
The manufacturing cost of the segment itself, the cost required for assembling the segment, and the time can be reduced.

[Brief description of the drawings]

FIG. 1 is a view showing a fitting state of a concave portion for dispersion and a convex portion for stress distribution formed on a joint surface between rings of a segment in the present invention.

FIG. 2 is a cross-sectional view showing a first example of a joint structure using joint hardware in the present invention, in a state before a head of a male joint is inserted into a hole of a female joint.

FIG. 3 shows a state in which the head of the male joint is inserted partway into the hole of the female joint.

FIG. 4 shows a state in which the head of the male joint is completely inserted into the hole of the female joint.

FIG. 5 is a sectional view of the female joint in a sliding direction of a tightening member.

FIG. 6 is a cross-sectional view of a position different from FIG.

FIG. 7 is a cross-sectional view showing a second example of the joint structure using the joint hardware in the present invention, in a state before the head of the male joint is inserted into the hole of the female joint.

FIG. 8 shows a state in which the head of the male joint is inserted partway into the hole of the female joint.

FIG. 9 shows a state where the head of the male joint is completely inserted into the hole of the female joint.

FIG. 10 is a perspective view of a frame plate in a second example.

FIG. 11 is a plan view of the same.

FIG. 12 is a diagram showing a relationship between a frame plate, a pair of fastening members, and an elastic member.

FIG. 13 shows other cross-sectional shapes of the elastic member (A), (B),
It is a figure shown in each of (C).

FIG. 14 is a view showing a conventional bolt box type joint.

FIG. 15 is a view showing a conventional cotter joint type joint.

FIG. 16 is a view showing a conventional one-touch type joint using a spring.

[Explanation of symbols]

 1.2 Segment 3.4 Joint surface between rings 5 Stress dispersing concave portion 6 Stress dispersing convex portion 7 Gap A Male joint 9.1 Head 11 Neck BC female connector 17 Frame plate 21 Opening 23/30 Hole 15・ 16 ・ 29 Elastic member 25 recess

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toru Ikegami 2-5-8 Kitaaoyama, Minato-ku, Tokyo Intra-company group (72) Inventor Hideo Watahiki 4-191-1, Shibaura, Minato-ku, Tokyo TEPCO (56) References JP-A-9-273395 (JP, A) JP-A 4-46195 (JP, U) JP-A 55-96997 (JP, U) Patent 2727419 (JP) , B2) (58) Field surveyed (Int. Cl. ⁷ , DB name) E21D 11/04 E21D 11/08

Claims (1)

(57) [Claims] A joint structure of a shield segment in which segments are joined by a male joint provided in one segment and a female joint provided in the other segment, wherein a joint surface between the rings of the segments is flattened. Surface and
One of the inter-ring joint surfaces has an arc-shaped concave portion for stress dispersion extending in the longitudinal direction of the inter-ring joint surface, and the other inter-ring joint surface has an arc-shaped projection with a smaller radius of curvature than the stress dispersive concave portion. Similarly, a stress dispersing convex portion extending in the longitudinal direction is provided, and when these concave portions and convex portions are fitted to each other, a minute gap due to a difference in curvature radius is formed only inside the concave portion and the concave and convex portions are formed. Part and curved surface contact,
The flat ring-to-ring joint surfaces are in a relationship of making planar contact on both sides in the thickness direction of the fitting portion between the concave portion and the convex portion. The male joint has a two-stage head, and The gap is the neck, and the two-stage head is projected from the inter-ring joint surface and buried in one segment. The female joint is formed in a recess formed in the inter-ring joint surface,
A frame plate for closing an opening surface of the recess, a fastening member for fastening a neck portion of the male joint, and an elastic member for biasing the fastening member are provided; An opening for receiving the two-stage head of the joint into the recess is provided, and the tightening member is prevented from falling out of the recess by a frame plate, and is guided by the frame plate to slide to attach the elastic member. The male joint is fitted to the neck of the male joint by force and tightened, and as a result, the extraction of the male joint from the female joint is prevented, and the stress dispersing concave portion and the stress dispersing convex portion are formed. Wherein the sliding in the thickness direction of the segments due to the gap between the segments is allowed.