JP3106005B2 - Segment for tunnel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel segment provided with a fitting connecting portion for joining with an adjacent segment at the abutting portion with the adjacent segment adjacent in the circumferential direction.

[0002]

2. Description of the Related Art Conventionally, as a tunnel segment of this kind, a dovetail groove portion in which a dovetail member for segment connection for joining with an adjacent segment adjacent in the circumferential direction can be fitted in a direction along the tunnel radial direction is used. A dovetail portion is provided at a butt portion between adjacent segments that are adjacent in the circumferential direction, and both segments are arranged so that the dovetail portions are opposed to each other at the butt portion. In some cases, the dovetail member is inserted into both dovetail grooves in a direction along the tunnel radial direction to connect both segments.

[0003]

An internal stress is generated in a tunnel segment assembled annularly in the ground by tunnel excavation due to an external force such as earth pressure or water pressure acting on an outer peripheral portion thereof. Among the internal stresses, the general stress distribution for bending is such that the maximum tensile stress acts on one of the outer peripheral portion or the inner peripheral portion in the segment thickness direction, and the maximum compressive stress acts on the other peripheral portion. Then, a distribution in which those stresses gradually decrease inward between the two peripheral portions is shown, and the internal stress becomes zero at a substantially intermediate portion (neutral axis) between the two peripheral portions.

That is, as the distance in the thickness direction from the neutral axis increases, a greater compressive stress or tensile stress acts on the segment along the neutral axis. Also, at the connection points in the circumferential direction of the segments,
The dovetail member bears the tensile stress to maintain the connected state of both segments.

However, according to the above-described conventional tunnel segment, the dovetails are provided along the radial direction of the tunnel, so that the dovetail members inserted into the both dovetails of the butting portion are not provided. Are arranged in the direction along the radial direction of the tunnel, and receive the internal stress in the distribution state changing in the longitudinal direction, similarly to the above-described stress distribution state of the segment.

[0006] In particular, a greater tensile stress acts on a portion closer to one peripheral portion of the segment, and the stress distribution in the dovetail member exhibits a biased state. There is a risk that stress will be concentrated on the local part of the dovetail member located between the two segments. Moreover, the portion where the tensile stress is concentrated is different depending on the installation position of the dovetail member in the tunnel and the state of action of the external force, so that it is difficult to uniquely set the portion. It is necessary to design a cross-section that can withstand the maximum tensile stress over the entire length of the substrate. Therefore, according to the conventional tunnel segment, the dovetail member used for the connection only partially counters the tensile stress in the cross section. It is necessary to increase the number of the dovetail members per one abutting portion or to increase the cross-section of the dovetail members, which is inefficient and uneconomical. This problem becomes more remarkable because the thickness of the segment increases as the tunnel diameter increases or the tunnel laying depth increases, and a large facility is required for inserting the dovetail member.

In view of the above, the above problem is solved, and as a tunnel segment capable of equally distributing the tensile stress acting on the connecting portion of the segment over the entire length of the dovetail member, the dovetail member for connecting the segment is arranged in the axial direction of the tunnel. It is proposed to provide a dovetail groove part which can be fitted in a direction along the fitting connection part.

According to the proposed tunnel segment, since the dovetail portion is provided with the dovetail groove in which the dovetail member can be fitted in the direction along the tunnel axis direction, the dovetails of the butting portion are provided. The dovetail member inserted into the groove,
It will be arranged in the direction along the tunnel axis direction.

Although the bending stress acting on the segment changes gradually in the thickness direction of the segment, it is uniform in the tunnel axis direction, so that the dovetail member arranged along the tunnel axis direction has In this case, a uniform tensile stress acts in the segment circumferential direction over the entire length. In other words, the cross section of the dovetail member is resistant to the tensile stress in all the cross sections thereof, and the cross section of the dovetail member with little waste can be set. By changing the installation position of the dovetail member in the thickness direction of the segment, it is possible to arbitrarily set the segment connection strength.

Further, since the segment is formed so that the direction of insertion of the dovetail member into the dovetail portion is along the direction of the tunnel axis, the insertion direction is made to follow the direction of action of the shield propulsion jack. It becomes possible to insert the dovetail member into the dovetail portion using a propulsion jack. This propulsion jack can also be used, for example, when unmanned in tunnel tunnel work, there is no need to manufacture a special machine for segment assembly and install it in the tunnel yard. There are functions that cannot be performed by segments.

As described above, the tunnel segment proposed above has a unique feature that is not present in the conventional tunnel segment, but on the other hand, in order to insert the dovetail member into the dovetail groove smoothly, the dovetail is used. It is necessary to provide an appropriate "play" for the dovetail members in the groove, and the "play"
Therefore, the adjacent segments connected to each other are not rigidly joined to each other, the gap between the abutting surfaces of both segments opens, and groundwater infiltrates into the tunnel from that part, and breaks at the segment connection point due to stress concentration. There is a risk that

Therefore, the present invention inherits the characteristics of the tunnel segment proposed above, solves the above-mentioned problems, hardly causes openings between adjacent segments adjacent in the circumferential direction, and is rigidly integrated. It is intended to provide a tunnel segment that can be connected.

[0013]

In order to achieve the above object, the characteristic structure of the tunnel segment in the present invention is as follows.
A dovetail portion for fitting a segment connecting dovetail member in a direction along the tunnel axis direction is provided in a fitting connection portion for joining with the adjacent segment at a butt portion with an adjacent segment adjacent in the circumferential direction, A tapered surface for bringing the dovetail groove portion closer to the adjacent segment side with the insertion of the dovetail member into the dovetail groove portion is formed on a part of the entire length of the locking portion with the dovetail member on the dovetail groove inner surface. A filling flow path capable of supplying a curable filler is provided in the dovetail portion.

The dovetail groove may be provided over substantially the entire length along the tunnel axis direction of the abutting portion, or the dovetail groove may be formed integrally with the tenon joint protecting metal part of the segment body. There may be.

[0015]

According to the characteristic structure of the tunnel segment of the present invention, the dovetail member guided by the tapered surface simply inserts the dovetail member into each dovetail portion of both segments adjacent in the circumferential direction of the tunnel. By pulling both dovetails in the approaching direction, it is possible to more strongly join the adjacent segments.

In addition, as the length of the tapered surface becomes longer, it becomes more difficult to form the tapered surface with higher accuracy. For example, due to a manufacturing error, when the dovetail member is inserted into the dovetail portion, the dovetail member is caught on the way. Although there is a danger, according to the tunnel segment of the present invention, the tapered surface is provided in a portion of the entire length of the locking portion with the dovetail member on the inner surface of the dovetail portion, where an adjacent segment is easily drawn. Compared to the case where the entire length of the locking portion is provided with the tapered surface, the tapered surface can be formed with higher precision, and the dovetail member insertion into the dovetail portion can be performed more smoothly and easily. It becomes possible.

In addition, since the filling channel for supplying the curable filler is provided in the dovetail, the curable filler can be supplied into the dove after the segments are connected. For example, if a filler having a high compaction strength is used as the filler, the space around the dovetail member installed in the dovetail groove can be completely filled with the filler and integrated, so that the segment coupling force can be increased. Can be transmitted more efficiently, a segment connecting portion having a high connecting strength can be formed, and it is possible to prevent the opening of the connecting portion and the like. Furthermore, if a highly waterproof material is used as the curable filler, a highly water-resistant segment connecting portion can be formed, and groundwater can be prevented from entering the tunnel from that portion.

If the dovetail groove is provided over substantially the entire length along the tunnel axis direction of the butting portion, the length of the dovetail member to be inserted can be arbitrarily set within the range with the total length of the dovetail groove being the maximum. By changing the length of the dovetail member to be inserted into the dovetail portion, it is possible to adjust the connection strength of the segments, and it is possible to adjust the dovetail member having substantially the same length as the total length of the dovetail portion. By inserting, it is possible to strongly join both segments over the entire length of the butted portion in the circumferential direction of the segments.

Further, if the dovetail portion is integrally formed with the tenon protection metal of the segment body, the strength of the dovetail portion itself is increased, and the dovetail portion having the high strength strongly receives the dovetail member. This makes it possible to strengthen the joint of the segments.

[0020]

Thus, according to the tunnel segment of the present invention, it is possible to apply a uniform tensile stress to the dovetail member for connecting the segments at the joint in the circumferential direction of the segment, and with a simple operation. In addition, the segment connecting structure capable of exhibiting high strength can be formed without waste, and it is possible to improve both safety and economy of the shield tunnel.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 3, a tunnel H is formed by connecting and fixing a plurality of tunnel segments (hereinafter simply referred to as segments) 1 according to the present invention to each other to form a peripheral wall X of a lateral hole. You. This tunnel H
In the construction of the shield tunnel excavator 2 equipped with a cutter 2a at the front end and a propulsion jack 2b at the rear end
By moving the cutter 2a around the tunnel axis P while moving the cutter 2a in the longitudinal direction by the extension of the propulsion jack 2b which takes a propulsive reaction force on the segment 1 assembled to the side wall peripheral wall X, the underground is dug. Propulsion distance per ring of segment 1 (typically 90 cm / rin
g in many cases), and then the propulsion jack 2
b is contracted, and the segments 1 are sequentially installed between the propulsion jacks 2b and the segments 1 of the side wall peripheral wall X.

As shown in FIG. 1, the segment 1 is made of precast concrete and has a curved shape along the circumferential direction of the tunnel. The grout material is injected into the grout injection hole 1a at the time when the formation of the lateral hole peripheral wall X is completed, so that the grout material is formed between the outer peripheral surface of the lateral hole peripheral wall X and the soil. It is filled and configured to prevent soil collapse.

The segment 1 is provided with a convex or concave fitting portion C for fitting with the adjacent segment 1 at a peripheral edge located in front and rear in an assembled state. H When the fitting portions C of the segments 1 adjacent in the longitudinal direction are fitted and connected to each other, the shear force acting on the joint surface between the segments 1 is reliably transmitted, and the plurality of segments 1 1 are combined to improve the bending rigidity of the entire tunnel H.

Further, a segment 1 is provided in a part of the fitting portion C.
A plate-shaped protection metal member 3 for protecting the front and rear peripheral edges is integrally provided. A rod-shaped embedding anchor portion 3a is provided on the back surface of the protective metal member 3. In addition to the purpose of protecting the segments 1, a through bolt 4 for connecting the adjacent segments 1 in the longitudinal direction of the tunnel H is provided. Are also used as fastening members for fixing the two segments 1 by screwing them together, and are integrally provided with the anchor portion 3a embedded in the concrete of the main body of the segment 1.
By embedding the anchor portion 3a in the concrete of the segment 1, the protective hardware 3 is firmly fixed to the segment 1, and the shape of each protective hardware 3 follows the outer shape of the fitting portion C. This prevents the fitting portion C from colliding with another object or receiving a large external force, thereby preventing the fitting portion C from being dropped or cracked.

In addition, a large external force is applied to the connecting portion of the segment 1 from the adjacent segment 1. However, since the above-mentioned protective metal member 3 has the purpose of protecting the fitting portion C, a comparative The strength of the connecting portion is high, and the connecting structure between the segments 1 is strong due to the high strength and the strong anchoring to the main body of the segment 1 by the above-mentioned anchor portion 3a. Has become.

As shown in FIG. 2, one of the protective hardwares 3 installed at the end has a circumferentially adjacent edge (butting surface D) of the segment 1 in the tunnel H circumferential direction. Dovetail member 5 for connecting to segment 1
However, a fitting connecting portion 7 having a dovetail groove 6 which can be fitted in a direction along the tunnel H axis P direction is formed.

The fitting connecting portion 7 is formed such that the inner hollow section is substantially semicircular, and the dovetail portion 6 is provided in the inner hollow portion. Further, the fitting connection portion 7 is provided along the entire length of the abutting surface D along the direction of the tunnel H axis P, and the end thereof is opened. The dovetail member 5 can be inserted along. Further, on the back side embedded in the concrete, a filling channel 8 capable of supplying various curable fillers such as cement or resin into the dovetail 6 from inside the tunnel H.
Are provided in a communication state. In order to lock the dovetail member 5, a part of the locking portion 7 a formed on the inner peripheral surface of the bent end portion of the fitting connection portion 7 has a wall thickness closer to the front end side in the insertion direction of the dovetail member 5. A tapered surface 9a inclined in the longitudinal direction is formed so as to be large, and a tapered portion 9b provided on a part of the dovetail member 5 is formed so as to be in contact with each other and to be fitted together. Note that the installation positions of the tapered surface 9a and the tapered portion 9b are provided at portions where the adjacent segments are easily drawn, and in the present embodiment shown in FIG. 2, they are provided at the ends in the shield propulsion direction.

Next, the dovetail member 5 for inserting into the dovetail groove 6 of the fitting connection part 7 to fit and connect the adjacent segments 1 will be described. The total length is substantially equal to the total length of the dovetail groove 6. The cross-sectional shape is H-shaped. A tapered portion 9 provided on a part of the contact surface 5a facing the locking portion 7a when inserted into the dovetail portion 6.
b is formed on an inclined surface corresponding to the tapered surface 9a.

According to the tunnel segment 1 of the present embodiment, the respective segments 1 are arranged so as to be adjacent to each other in the circumferential direction. By inserting the dovetail member 5 from the direction of the tunnel axis P, the tapered surface 9 of the fitting connection portion 7 is formed.
The tapered portion 9b of the dovetail member 5 abuts on the a, and as it is pushed further inward, a tightening force in a direction perpendicular to the tapered surface 9a acts between the tapered surface 9a and the tapered portion 9b, and It becomes possible to connect the mating connection portions 7 in a state of being tightened in a direction approaching each other.

[Another Embodiment] Another embodiment will be described below.

<1> The dovetail groove 6 may be partially provided in addition to the one provided substantially over the entire length of the butted portion D described in the previous embodiment. If a plurality of dovetail grooves 6 are provided at intervals in the thickness direction with respect to the butting portion D, the dovetail groove 6 into which the dovetail member 5 is fitted can be selectively determined from among them.
For example, any dovetail 6
The dovetail member 5 can be fitted to the
Both safety and economy can be improved.
Further, as shown in FIG. 4, if the end of the dovetail groove 6 opposite to the insertion side of the dovetail member 5 is formed in a closed state, for example, the filler material is inserted into the dovetail groove 6 of the joined segment connecting portion. It is possible to prevent the filler material from leaking from the end portion when filling is performed. Furthermore, if the anchor 10 as shown in the figure is provided on the back side of the dovetail groove 6, the integrity of the segment 1 with concrete is improved, and the segment connection can be performed with higher force. .

<2> Further, the shapes of the dovetail groove 6 and the dovetail member 5 are not limited to those described in the previous embodiment. The dovetail member 5 may be provided with a dovetail groove 6 having a cross-sectional shape that can be freely fitted. In short, the dovetail member 5 only needs to be formed in a shape and structure that can be fitted to each other and connect the two segments 1. These configurations are collectively referred to as a dovetail groove 6. Furthermore, if a swelling part having a large swelling property (formed of, for example, a swellable urethane resin) is attached to the dovetail groove 6 or the dovetail member 5, the swelling can be performed even if groundwater enters the connection part. In order for the part to swell and increase its volume, the inflow path of the groundwater is closed to prevent the ant groove 6 and the ant member 5 from rusting and to suppress the inflow into the tunnel pit.

<3> The dovetail member 5 is not limited to the one described in the previous embodiment.
As shown in the figure, if the groove 11 is provided along the longitudinal direction, the filler is guided to the corners of the space in the dovetail groove 6 along the groove 11 when the filler is supplied into the dovetail groove 6. It is possible to perform more reliable filling. As another embodiment, for example, if the dovetail member 5 is divided into a plurality in the longitudinal direction, the dovetail groove 6
When the dovetail member 5 is inserted into the space, the working space between the propulsion jack 2b and the segment 1 can be reduced. Further, as another embodiment in which the working space can be reduced, a plurality of the dovetail members 5 divided in the longitudinal direction are connected by a flexible material, and one end of the dovetail members 5 group is inserted into the dovetail groove 6. If the other end is formed so as to bend in the radial direction of the tunnel H, the dovetail member 5 can be inserted in a small space.

<4> Further, as shown in FIG. 6, the convex portions 1 each of which can be fitted to the tapered surface 9a and the tapered portion 9b.
If the 2a and the recess 12b are separately provided, it is possible to prevent the inner surfaces of the segments 1 from being misaligned.

<5> Further, the dovetail member 5 is used not only for the segment arrangement in a state where the adjacent segments 1 are in contact with each other, but also for example, both segments 1 are arranged at intervals in the circumferential direction of the tunnel H. In the state
It may be arranged between them and formed in a structure capable of receiving earth pressure or water pressure from outside the tunnel H.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a state of assembling segments according to an embodiment.

FIG. 2 is a partially cutaway perspective view showing a connecting portion of a segment in the embodiment.

FIG. 3 is an overall view showing a shield tunnel.

FIG. 4 is a perspective view showing a fitting connection portion of another embodiment.

FIG. 5 is a perspective view showing a fitting connection portion of another embodiment.

FIG. 6 is a perspective view showing a fitting connection portion of another embodiment.

FIG. 7 is a perspective view showing a tenon protection metal part according to another embodiment.

FIG. 8 is a perspective view showing a tenon joint protecting metal part of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Segment 3 Protective hardware 5 Dovetail member 6 Dovetail part 7 Fitting connection part 7a Locking part 8 Filling flow path 9a Tapered surface D Butt part P Shaft center

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Ishihara 3-3-1 Nihombashi Muromachi, Chuo-ku, Tokyo Kubota Corporation Tokyo Head Office (72) Inventor Yasusuke Onibashi 3-3-1 Nihonbashi Muromachi, Chuo-ku, Tokyo No. Kubota Corporation Tokyo Headquarters (56) References JP-A-63-118497 (JP, A) JUN 50-33847 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) E21D 11/04

Claims (3)

(57) [Claims] 1. A tunnel segment in which a fitting connection (7) for joining with the adjacent segment (1) is provided at an abutting portion (D) with an adjacent segment (1) adjacent in the circumferential direction. The dovetail groove (6), into which the dovetail member (5) for segment connection can be fitted in the direction along the tunnel axis (P) direction,
The dovetail groove (6) is provided in the fitting connection part (7), and is inserted with the dovetail member (5) into the dovetail groove (6).
Is formed on a part of the entire length of the locking portion (7a) with the dovetail member (5) on the inner surface of the dovetail groove (6) to make the taper surface (9a) close to the adjacent segment (1) side, A tunnel segment provided with a filling channel (8) capable of supplying a curable filler in the dovetail portion (6). 2. The tunnel segment according to claim 1, wherein the dovetail groove (6) is provided over substantially the entire length along the direction of the tunnel axis (P) of the butting portion (D). 3. The tunnel segment according to claim 1, wherein the dovetail groove is formed integrally with a tenon protection metal part of the main body of the segment.