JP4090643B2 - Segment joint structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a joint structure for joining segments to each other, and more particularly to a joint structure of a concrete segment (segment piece) used when a tunnel is constructed by a shield method.
[0002]
[Prior art]
In the shield method, the outer shell (shield) is excavated while protecting the earth and sand in front of the tunnel. At the same time, the outer shell is pushed forward, and in parallel with this, the segments are assembled into a ring shape at the rear of the outer shell. The tunnel inner wall (lining) is formed by sequentially and continuously building in the tunnel axis direction. To push out the outer shell, there is a large force of several hundred tons to several thousand tons, but the segment receives the reaction force and feeds the outer shell forward with a jack.
[0003]
FIG. 5 is a partially broken perspective view of a shield tunnel under construction. 1 is a shield machine, 1a is a cylindrical steel outer shell, 1b is a cutter head of an excavator, 2 is ground, 3 is a segment ring, 3a Is a segment and 4 is a shield jack. The shield machine 1 is arranged at the head position of the tunnel under construction, and the shield machine has an outer casing 1a formed in a cylindrical shape. A cutter head 1b for excavating the ground 2 is provided at the front part of the outer casing 1a, and a plurality of shield jacks 4 are mounted on the inner periphery of the rear part of the outer casing 1a. Each jack is selectively mounted on the front end of the segment in such a way that a reaction force can be determined. In the rear space 8 in the outer casing 1a, an erector (not shown) for assembling the segment is provided in such a manner that the segment is received from the conveying device (not shown), is gripped, and can be rotated and positioned. On the rear side of the shield outer casing 1a, a tunnel composed of segments 3a is constructed and formed in a cylindrical shape. In the shield tunnel, segments 3a each formed in an arc shape are connected in the circumferential direction to form a segment ring 3, and the segment ring 3 has already been built in the tunnel axial direction as the shield machine 1 advances. Constructed by adding to the segment ring.
[0004]
That is, an arc-shaped segment (segment piece) 3a having a predetermined width is assembled in a ring shape to form one segment ring 3, and every time the shield tunneling advances by one ring, the tunnel of the segment ring already built Segments are built in the form of adding new segment rings in the direction of travel. Therefore, the outer shell 1a of the shield machine moves forward in a form that seeks a reaction force at the front end of the latest segment ring, and as the shield machine 1 moves forward, a tunnel composed of segment rings is built behind it.
[0005]
The segment 3a includes a concrete segment, a steel segment, a steel-concrete composite segment, and the like depending on the material. In the case of using a concrete segment as a segment, in order to fasten adjacent segments, conventionally, a box-shaped depression called a bolt box and a bolt hole for joining are provided in the segment, and these are used to fasten the bolt. Segment joints to be performed were common (Japanese Patent Laid-Open No. 10-153095). However, there is a problem that the bolt fastening becomes troublesome work, so recently, in order to mechanize the segment assembly, there is a one-touch type fitting hardware that can be fastened by simply pressing a new segment against an already built segment. Various types have been developed.
[0006]
FIG. 6 is an enlarged cross-sectional view of a conventional one-touch segment joint portion, and 3a ₁ and 3a ₂ are segments constituting adjacent segment rings. In this conventional one-touch joint metal fitting, a segment 3a is formed such that a male metal piece 5 protrudes and is fixed to _one segment 3a ₁ side of a segment to be joined, and a female metal piece 6 is formed on the other segment 3a ₂ side. It is attached by embedding it in the concrete of No. ₂ , and the male and female hardware 5 and 6 are fastened by the pushing force by the machine.
[0007]
[Problems to be solved by the invention]
However, in the conventional one-touch type segment joint structure, when the male metal object 5 is simply pushed into the female metal object 6 by mechanical force, the air present in the concave portion 7 is compressed inside the female metal object, and thus the pushing operation is hindered. There was a problem that the male hardware 5 was pushed back. Further, if the pushing operation is forced against the return force, there is a risk that the concrete constituting the segment 3a ₂ is cracked by the compressed air inside the female hardware.
In view of the above, an object of the present invention is to enable the joint of the joint part to be smoothly performed in the one-touch type joint metal so that the air inside the female metal is not compressed.
[0008]
[Means for Solving the Problems]
According to the present invention, (1) a recess formed by embedding a female metal having an inner diameter slightly smaller than the outer diameter of the male metal in the segment, and (2) a male metal protruding and secured to another segment. This is achieved by a joint structure of a segment provided with an air discharge portion for discharging the air in the recess to the outside when being pushed into the recess.
The air discharge part is formed by providing an air hole in the female metal part near the terminal end of the concave part, and mounting a cushioning material capable of air permeation on the outer periphery of the female metal object and embedding it in the segment. . Alternatively, the air discharge part is provided with an air hole in the female metal part near the terminal end of the recess, and a cushioning material having a plurality of longitudinal air release longitudinal grooves and a lateral groove connecting the longitudinal grooves in the circumferential direction. The outer periphery of the female metal fitting is mounted so that the lateral groove and the air hole communicate with each other and embedded in the segment.
As described above, since the air discharge portion is provided in the present invention, the air inside the female hardware is not compressed, the joint of the joint portion can be smoothly performed, and damage to the concrete constituting the segment can be eliminated. .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
(A) First Embodiment FIG. 1 is an explanatory view of a method for joining segments of the present invention having a one-touch type joint, and FIG. 2 is a sectional view of the segment using the joint of the present invention.
As shown in FIG. 1, joint portions are formed on _four side surfaces (joint surfaces) 11 _{1 to} 11 ₄ in the tunnel axial direction and the tunnel circumferential direction of the segments 3a ₁ and 3a ₂ . Among these, a known quick joint is provided at the joint portion of the segment adjacent in the circumferential direction, but the illustration and description are omitted because it is not related to the present invention. One-touch type joints are used for the joint portions of the segments 3a ₁ and 3a ₂ adjacent in the tunnel axis direction. That is, a plurality of (three sets in the figure) one-touch joint portions are provided on the joint surfaces 11 ₁ and 11 ₂ of the segments 3a ₁ and 3a ₂ , and the male portions 12 ₁ to 12 in the joint portion of _one segment 3a ₁ By joining 12 ₃ to the female portions 13 _{1 to} 13 ₃ in the joint portion of the other segment 3a ₂ by pressure bonding, both are joined.
[0010]
Each of the segments (segment pieces) 3a ₁ and 3a ₂ has a concrete segment body 15 formed in an arc shape curved in a direction intersecting with the paper surface in FIG. 2, and one joint of the segment body 15 in the tunnel axial direction. 11 ₂ side is Yubu 12 ₁ to 12 _3, the female part _{131-134 3} is formed on the other joint face 11 _1. That is, in the illustrated example, three male portions 12 _{1 to} 12 ₃ and three female portions 13 _{1 to} 13 ₃ are provided on both end surfaces in the tunnel axis direction of one segment. As shown in FIG. 2, the male part 16 is provided in the male part in a form in which half of the male part 16 is embedded in the concrete constituting the main body part of the segment and the remaining half protrudes. Cement mortar is filled with the concrete of the segment body. A female metal part 17 is provided in the female part so as to be embedded in the concrete so as not to protrude from the end face of the segment, and a concave part 18 is formed in the female metal part because the concrete is not filled. The inner diameter D1 of the female hardware 17 is slightly smaller than the outer diameter D2 of the male hardware 16, and therefore, when the segment is installed, the male hardware of the new segment 3a ₁ is added to the female hardware of the segment 3a ₂ already installed. When the is pushed in, the male metal object expands the diameter of the female metal object, and is frictionally fixed to the concrete of the segment.
[0011]
FIG. 3 is an enlarged view of the joint structure, 15 is a segment body, 17 is a female metal, 18 is a space (concave) into which the male metal is pushed, 19 is a cushioning material, In the circumferential direction, one or a plurality of holes 17a for air escape are formed penetratingly. In the embodiment, the diameter of the air hole 17a is 4 mm. Further, a cushioning material 19 made of polyethylene foam or the like, which is dense and impermeable to cement, is wound around the outer periphery of the female metal piece 17 in a cylindrical shape so as to close the air holes 17a. As a result, air can go outside through the air hole 17 a and the buffer material 19 in the vicinity of the end of the recess 18. The buffer material 19 absorbs a slight shift in the position and axial direction of the male metal 16 when the male metal 16 is originally pushed into the female metal 17 when joining the segments. Function to fasten correctly.
[0012]
When manufacturing a segment having the above joint structure, first, a male metal 16 and a female metal 17 filled with cement mortar together with metal joints on both end faces in the circumferential direction of the tunnel are formed on a segment forming mold (not shown). Temporarily fixing at a predetermined position, concrete of a predetermined composition is placed and filled in the mold. At this time, the female metal object 17 is embedded in the concrete, but since the buffer material 19 having the above-described conditions is wound around the air hole 17a, the concrete placed is used as the buffer material. 19 does not ooze or enter the recess 18 from the air hole 17a.
[0013]
When the segment formed as described above is installed in the shield tunnel, a new male metal 16 of the segment 3a ₁ is inserted into the female metal 17 of the already installed segment 3a ₂ as shown in FIG. We will conclude both by pushing in using force. At this time, since the inner diameter D1 of the female metal piece 17 is slightly smaller than the outer shape D2 of the male metal piece 16, the air in the recess 18 pushed by the insertion of the male metal piece 16 is buffered from the air hole 17a (FIG. 3). It passes through the inside of the material 19 and falls outside the segment 3a ₂ , and air is no longer compressed behind the recess 18.
Therefore, the joint metal is pushed in smoothly, and is not pushed back or cracked in the segment concrete, and is securely and firmly joined and integrated with the adjacent segment.
[0014]
(B) Second Embodiment FIG. 4 is an enlarged view of another joint structure of the present invention, FIG. 4 (a) is a partially enlarged longitudinal sectional view, and FIG. 4 (b) is a cross-sectional view of FIG. FIG. 5 is a cross-sectional view taken along the arrow b, and the same parts as those in the first embodiment of FIG. 15 is a segment main body, 17 is a female metal object, 18 is a space (concave part) into which the male metal object is pushed, 19 is a cushioning material formed of a material that does not allow cement to penetrate, and air vent grooves 19a ₁ and 19a ₂ are formed. is there.
One or more holes 17a are formed in the female metal part near the terminal end of the recess 18 in the circumferential direction so as to penetrate therethrough. Further, on the outer periphery of the female fittings 17, cushioning material 19 is wound around a cylindrical shape so as to communicate the air vent groove 19a ₂ and the air hole 17a. The air vent groove is provided in the circumferential direction in such a manner that a plurality of longitudinal grooves 19a ₁ provided substantially continuously in the axial direction of the female metal piece and the plurality of vertical grooves communicate with the air hole 17a of the female metal piece. The lateral groove (circumferential groove) 19a ₂ is formed. With the above-described configuration, air can go to the outside through the air hole 17a near the bottom of the recess 18 and the air release grooves 119a ₁ and 19a ₂ of the cushioning material 19. The shape of the groove is arbitrary.
[0015]
A segment having the joint structure is formed by the same manufacturing method as in the first embodiment. When such a segment is built in the shield tunnel, a new male metal 16 of the segment 3a ₁ is pushed into the female hardware 17 of the segment 3a _{2 which has} already been built using the pushing force of the shield jack as shown in FIG. We will conclude both in the form. At this time, since the inner diameter D1 of the female hardware 17 is slightly smaller than the outer diameter D2 of the male hardware 16, the air in the recess 18 pushed by the insertion of the male hardware 16 is the air hole 17a (FIG. 4) → buffer. The material 19 passes through the horizontal groove 19a ₂ → the vertical groove 19a ₂ and goes out of the segment concrete, and air is not compressed in the back of the concave portion 18. Therefore, the joint metal is pushed in smoothly, and is not pushed back or cracked in the segment concrete, and the adjacent segments are securely and firmly joined and integrated.
The present invention has been described with reference to the embodiments. However, the present invention can be variously modified in accordance with the gist of the present invention described in the claims, and the present invention does not exclude these.
[0016]
【The invention's effect】
As described above, according to the present invention, since the air discharge portion is provided, the air inside the female metal object is not compressed, the joint of the joint portion can be smoothly performed, and damage to the concrete constituting the segment can be eliminated.
Further, according to the present invention, the air escape portion can be formed with a simple configuration using the air hole and the cushioning material.
Further, according to the present invention, the air in the recess pushed by the insertion of the male metal object passes through the inside of the cushioning material from the air hole, or passes through the air escape groove of the cushioning material, and then escapes to the outside of the segment. The air is no longer compressed in the back of the recess, and the fitting hardware can be pushed in smoothly, so that it is not pushed back and the segment concrete is not cracked. Therefore, adjacent segments can be securely and firmly joined and integrated.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a method for joining segments according to the present invention.
FIG. 2 is a sectional view of a segment using the joint of the present invention.
FIG. 3 is a partially enlarged sectional view of the joint of the present invention.
FIG. 4 is another joint embodiment of the present invention.
FIG. 5 is a partially broken perspective view of a shield tunnel under construction.
FIG. 6 is an enlarged cross-sectional view of a conventional segment joint portion.
[Explanation of symbols]
3a ₁ , 3a ₂ ··· Segment 11 _{1 to} 11 ₄ ·· Joint surface 15 · · Segment main body 16 · Male hardware 17 · Female hardware 17a · · Air vent hole 18 · · Space where male metal is pushed ( Recess)
19. Buffer material

Claims (2)

In joint structures for joining segments together,
A concave part formed by embedding a female metal part having an inner diameter slightly smaller than the outer diameter of the male metal part, and a male metal object protruding and fixed to another segment is pushed into the concave part, and the air in the concave part is discharged to the outside. With an air exhaust,
The air discharge part is formed by providing an air hole in the female metal part near the terminal end of the concave part and embedding the air permeable buffer material on the outer periphery of the female metal object and embedding it in the segment. To
The joint structure of the segment characterized by this. In joint structures for joining segments together,
A concave part formed by embedding a female metal part having an inner diameter slightly smaller than the outer diameter of the male metal part, and a male metal object protruding and fixed to another segment is pushed into the concave part, and the air in the concave part is discharged to the outside. With an air exhaust,
A cushioning material having an air hole in the female metal part near the terminal end of the recess, and a plurality of vertical grooves for venting air and a lateral groove connecting the vertical grooves in the circumferential direction. , Formed so that the lateral groove and the air hole communicate with the outer periphery of the female metal fitting and are embedded in the segment.
The joint structure of the segment characterized by this.

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