JPH06307197A - Joint construction of segment - Google Patents

Abstract

PURPOSE:To make breaking of a segment hard by tolerating displacement of the segment against external force and to promote durability by dispersing stress in broad range of the segment to bear. CONSTITUTION:Joint construction of segments is applied to a joint section between segments 10 adjacent in the circumferential direction, one of the joint ends of a pair of segments 10 butted to each other is formed into a projected curve 11, and the other is formed into a recessed curve 12. The projected curve 11 and recessed curve 12 are fitted to each other relatively in a slidable manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint for a segment in which a pair of arc-shaped plate segments to be joined are arranged along the circumferential direction and the joining end faces, which are end faces in the circumferential direction, are joined to join the two. Regarding the structure.

[0002]

2. Description of the Related Art In the recent tunnel construction method, while excavating the ground by a shield machine, arc-shaped segments (generally made of reinforced concrete) are sequentially joined behind the ground to construct a cylindrical tunnel wall. The so-called shield construction method has become popular.

As shown in FIG. 7, the above-mentioned segments are joined to each other by connecting the plate-like joint fittings 2 which are buried in the joining end faces 1a of the segments (in this case, reinforced concrete) 1 to be joined to each other with bolts 3 and nuts. The means of fastening by 4 is general. On the inner surface (concave surface) side of the segment 1, a fastening recess 5 is formed in advance for enabling the arrangement of the bolt 3 and the nut 4 and the fastening work thereof.

[0004]

However, in the case of joining the segments as described above, the external force acting relatively between the joined segments 1 and 1 is caused by the fastening force of the bolt 3 and the nut 4. Since it is supported, when the larger segment 1 is used or when the external force such as earth pressure is large, the bolt 3 and the nut 4 need to be large, which causes various inconveniences.

That is, as the effect of increasing the size of the bolts 3 and the nuts 4, the fastening recesses 5 and the bolt holes are increased in size, so that the proof strength is locally reduced particularly at the joint end of the segment 1 and There is a concern that the tools will become larger and the workability of fastening will decrease. Further, as measures against the decrease in the proof stress, it is conceivable to reinforce the vicinity of the joint end face of the segment 1 by reinforcing bars or the like to disperse the stress or increase the thickness of the segment 1, but in any case, It raises costs and does not lead to a fundamental solution to the problem.

The present invention has been made in view of the above-mentioned problems, and by allowing displacement of the segment with respect to an external force, it is difficult to break, and further, stress is dispersed and supported in a wide range of the segment to make it durable. An object of the present invention is to provide a joint structure for a segment with improved force.

[0007]

In the joint structure for a segment according to claim 1, a ridge is formed on one of the joint end faces to form a convex curved surface extending along the width direction of the segment, and the joint end face of the joint end face is formed. On the other hand, a concave curved surface having a shape that can be fitted to the convex curved surface was formed, and the concave curved surface and the convex curved surface were fitted so as to be slidable relative to each other.

The segment joint structure according to claim 2 is the segment joint structure according to claim 1, wherein the concave curved surface and the convex curved surface slide on at least one of the concave curved surface and the convex curved surface. The provision of a sliding member for smoothing the above is a means for solving the above problems.

The segment joint structure according to claim 3 is the segment joint structure according to claim 1 or 2, wherein at least one of the concave curved surface and the convex curved surface is
Applying a lubricant was used as a means for solving the above-mentioned problems.

[0010]

According to the joint structure of the segment described in claim 1, when the external force is unevenly distributed to the adjacent segments in the circumferential direction, the concave curved surface and the convex curved surface slide relative to each other according to the difference in the external force. , Is displaced until the uneven distribution of the external force is almost eliminated. For a segment whose joint end is displaced due to the displacement of the end face, the joint end on the other side is displaced in the opposite direction relative to the displacement of the joint end face on one side, so the segment center is rotated in the thickness direction. Move.

Further, since the segments adjacent in the circumferential direction support the external force via the concave and convex curved surfaces, the stress against the external force is generated in a wide range of the entire joint end portion.

According to the joint structure of the second aspect of the invention, the sliding member and the curved surface of any of the concavities and convexities, or the sliding members relatively smoothly slide, and the stress generated in the segment in the displaceable range is reduced.

According to the joint structure of the segment described in claim 3, in addition to the effect of the invention of claim 2, by supplementing the lubricant, the effect of the invention of claim 2 can be maintained. It's easy.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In the figure, reference numeral 10 is a segment constituting the joint structure of the present invention, 11 is a convex curved surface, 12 is a concave curved surface, 13 is an axial convex portion, 14 is an axial concave portion, 15 is a metal plate (sliding member), 16 is a lubricant.

In the figure, the same components as those in FIG. 4 are designated by the same reference numerals to simplify the description.

The segment joint structure of this embodiment is applied to the joint portion of the segments 10 which are adjacent to each other in the circumferential direction, and one of the joint end faces of the pair of segments 10 abutted to each other has the convex curved surface. 11 and the other is formed on the concave curved surface 12, and the convex curved surface 11 and the concave curved surface 12 are fitted so as to be slidable relative to each other.

The convex curved surface 11 has a ridge line in the segment 10.
Is formed in a shape extending along the width direction of the. The concave curved surface 12 is formed on an outer surface that substantially matches the outer surface of the convex curved surface 11.

On the surfaces of the convex curved surface 11 and the concave curved surface 12, a smooth polished metal plate 15 is attached. Further, a lubricant 16 such as grease is applied to the surface of the metal plate 15 so that the convex curved surface 11 and the concave curved surface 12 slide smoothly.

By replenishing the lubricant 16, it is easy to maintain the smooth sliding motion between the convex curved surface 11 and the concave curved surface 12.

The metal plate 15 may be provided on only one of the convex curved surface 11 and the concave curved surface 12, or may be installed between the convex curved surface 11 and the concave curved surface 12. . Further, the lubricant 16 is made of resin or the like and is made of a metal plate 15.
It is also possible to apply a material that forms a coating that reduces friction on the surface.

The segment 10 is an arc-shaped plate made of reinforced concrete, and a plurality of segments are connected in the circumferential direction to form a single ring body as shown in FIG. Each segment 10 has a convex curved surface 11 on one side.
However, a concave curved surface 12 is formed on the other side, and the convex curved surface 11 and the concave curved surface 12 are combined with each other to be joined to each other to form the ring body.

An axial convex portion 13 is formed on the end surface of each segment 10 on one side in the axial direction so as to be joined to another segment 10 in the axial direction. On the other hand, an axial concave portion 14 that fits with the axial convex portion 13 is provided on the end surface of the segment 10 on the other side in the axial direction. The axial convex portion 13 is
It is a groove having a trapezoidal cross section formed in the central portion of the segment 10 in the thickness direction, and extends in the entire length direction of the segment 10. A gap of several millimeters is formed between the axial convex portion 13 and the axial concave portion 14 when they are fitted together. In the ring body, since the segments 10 constituting the ring body are aligned in the same direction, the axial convex portion 13 extends on one side of the axial end surface in the entire circumferential direction of the ring body, and on the other side. The axial recess 14 extends in the entire circumferential direction. The joint structure of the segment includes a metal plate 15
By the action of the lubricant 16, the convex curved surface 11 and the concave curved surface 12 slide smoothly with respect to each other. However, as shown in FIG. 3, all the segments 10 forming the ring are of the present embodiment. When connected in a joint structure, the joint portion has a bending moment of zero with respect to an external force, while each segment 10 receives a bending moment of either positive bending or negative bending. Therefore, the center of deformation (rotation) of each segment 10 forming the ring is
It is rational to set the center of the arc length of the segment 10. As shown in FIG. 4, a distance Rp from the center of the joint to the rotation center of the segment 10, a distance Rc between the ring center and the center of the joint, and a central angle corresponding to the segment 10 at the ring center. Where θ is θ, the equation of Rp = Rctan (θ / 2) is established.

The segments 10 are joined together in the circumferential direction to form a ring body, and the ring bodies are joined together by fitting the axial projections 13 and the axial recesses 14 into the tunnel wall body. Is configured.

The operation and effect of this embodiment will be described below.

In the joint structure of the segments, when the external force is unevenly distributed to the adjacent segments 10 in the circumferential direction, the convex curved surface 11 and the concave curved surface 12 are mutually opposed in the thickness direction of the segment 10 according to the difference in the external force. It slides and is displaced until the uneven distribution of the external force is almost eliminated. Segment 10 whose joint end is displaced by displacement of convex curved surface 11 or concave curved surface 12
With respect to the displacement of the joint end surface on one side, the joint end portion on the other side is displaced in the opposite direction, so that it rotates in the thickness direction about the center of the segment 10.

Further, the segments 10 adjacent in the circumferential direction
Since the external force is supported via the concave and convex curved surfaces 11 and 12, the stress against the external force is generated in a wide range of the entire joint end portion where the convex curved surface 11 and the concave curved surface 12 are in contact with each other. In addition,
The range of relative sliding between the convex curved surface 11 and the concave curved surface 12 is determined by the interval of the gap formed between the axial convex portion 13 and the axial concave portion 14.

On the other hand, the joint structure of this embodiment generally exhibits an elastic response to a relatively small bending moment.

There is a spring constant of the joint for handling this elastic state. In FIG. 5, if the spring constant is k, the bending moment is M, and the member rotation angle is θ, k = M /
The relational expression of θ is established.

Further, as shown in FIG. 6, in order to prevent cracks and cracks in the corners between the segments 10 connected by the joint, when the interval δ is provided, the size of the above-mentioned gap at the outermost portion of the joint. If the opening angle of the joint center with respect to the length δ is θ and the thickness of the segment 10 is h, then δ = h / 2 · tan θ
The relational expression of is established.

Therefore, according to the joint structure of the segments, since the displacement of the segment 10 against the external force is allowed, the stress against the external force is applied until the convex curved surface 11 and the concave curved surface 12 are displaced to the limit of relative sliding. Hardly occurs, and when the convex curved surface 11 and the concave curved surface 12 are displaced to the limit of relative sliding, the axial convex portion 13 and the axial concave portion 14
The stress against the external force can be generated and dispersed in a wide range at the overlapping portion of 1 and the overlapping portion of the convex curved surface 11 and the concave curved surface 12, and the durability is improved.

Further, in the joint structure of the segment, since it is not necessary to form a fastening recess, a bolt hole or the like in the segment 10, there is no local decrease in proof stress and the overall strength is improved, of course. Since it can be simplified, the manufacturing is simple and the cost is reduced.

On the other hand, the metal plate 15 and the lubricant 16 act effectively particularly in the joint structure of the segment to which a large load acts to maintain the smooth sliding of the convex curved surface 11 and the concave curved surface 12, The durability of 10 can be improved.

[0034]

As described above, in the joint structure for a segment according to claim 1, a ridge line is formed on one of the joint end faces to form a convex curved surface extending along the width direction of the segment, and the joint is formed. A concave curved surface having a shape that can be fitted to the convex curved surface is formed on the other end face, and the concave curved surface and the convex curved surface are fitted so as to be relatively slidable. Therefore, (1) a segment against external force Since the displacement is allowed, the stress against the external force hardly occurs until the convex curved surface and the concave curved surface are displaced to the limit of relative sliding, so that the durability is improved. (2) Convex curved surface and concave curved surface When and are displaced to the limit of relative sliding, stress against the external force can be generated in a wide range by generating a stress against the external force at the overlapping portion of the axial convex portion and the axial concave portion or the overlapping portion of the convex curved surface and the concave curved surface. , Durability is improved,
(3) Since it is not necessary to form fastening recesses, bolt holes, etc. in the segment, there is no local decrease in proof stress and the overall strength is improved, and the structure can be simplified and the segment can be manufactured easily. For this reason, it has an excellent effect that the cost is reduced.

According to a second aspect of the present invention, there is provided the segment joint structure of the first aspect, wherein the concave curved surface and the convex curved surface are slid on at least one of the concave curved surface and the convex curved surface. Since the sliding member for smoothing is provided, smoothness of sliding between the convex curved surface 11 and the concave curved surface 12 can be maintained, and the durability of the segment can be improved.

According to a third aspect of the present invention, there is provided the segment joint structure according to the first or second aspect, wherein at least one of the concave curved surface and the convex curved surface comprises:
Since the lubricant is applied, the above-mentioned claim 1
Alternatively, it is easy to maintain the smoothness of sliding by appropriately replenishing the lubricant.

[Brief description of drawings]

FIG. 1 is a partial perspective view showing one side of a circumferential end portion of a segment constituting a joint structure of a segment of the present invention.

FIG. 2 is a partial perspective view showing the other side of the circumferential end portion of the segment shown in FIG.

FIG. 3 is an overall perspective view showing a ring body formed by connecting segments in the circumferential direction by using the joint structure of the present invention.

FIG. 4 is a schematic diagram showing rotation of a segment joined by the joint structure of the present invention with respect to an external force.

5 is a schematic diagram showing relative rotation of a pair of joined segments of FIG. 4;

FIG. 6 is a schematic view showing a mode for preventing cracks and breaks at corners of the segment of FIG. 5;

FIG. 7 is a partial perspective view showing a conventional joint structure of a segment.

[Explanation of symbols]

 10 segments 11 convex curved surface 12 concave curved surface 15 sliding member (metal plate) 16 lubricant

Claims (3)

[Claims] 1. A joint structure of a segment for joining a pair of arcuate plate-shaped segments to be joined together by joining the joining end faces which are end faces in the circumferential direction in a state of being along the circumferential direction. A ridge is formed on one of the joining end surfaces to form a convex curved surface extending along the width direction of the segment, and a concave curved surface having a shape that can be fitted with the convex curved surface is formed on the other of the joining end surfaces. A segment joint structure, characterized in that the convex curved surface and the convex curved surface are fitted so as to be slidable relative to each other. 2. The joint structure for a segment according to claim 1, wherein a sliding member that smoothly slides between the concave curved surface and the convex curved surface is provided on at least one of the concave curved surface and the convex curved surface. A joint structure of a segment characterized by the above. 3. The segment joint structure according to claim 1 or 2, wherein a lubricant is applied to at least one of the concave curved surface and the convex curved surface.