JP4945294B2 - segment - Google Patents

Description

  The present invention relates to a segment of a tunnel.

In tunnel construction, there is a case where the ground is blocked early using a segment in order to prevent the collapse of the ground and to prevent the inflow of groundwater into the tunnel.
Tunnel construction using such a segment is performed by continuously arranging segment rings assembled in a desired shape formed using a plurality of segments in the tunnel axis direction.

Usually, the segment ring is constructed by connecting joint plates disposed on the segment joint surfaces of the segments through joint bolts.
Since a general segment ring formed in an annular shape is in a stress state of axial force dominant type, the bending moment acting on the joint portion of the segment is relatively small, and as a joint plate disposed on the segment joint surface, It was comprised by arrange | positioning a thin steel plate in a segment joint surface.

However, in recent years, in tunnel constructions such as highway junctions and railway station buildings, a large-diameter tunnel may be provided, and then the space between the double tunnels may be widened.
In this way, in the tunnel construction that cuts and expands between the twin tunnels, the segment ring is in a missing circle state, so that it becomes a bending-dominated stress state unlike the annular segment ring in a normal single tunnel.

  The bending-dominated stress state of the segment is greatly influenced by bending acting on the joint. Therefore, it is necessary to increase the use of the joint structure compared to the conventional method, such as increasing the strength by increasing the thickness of the joint plate. was there. The increase in the joint structure causes an increase in the weight of the segment, which may affect the workability and may hinder the reduction of the construction cost.

  For this reason, for example, as shown in Patent Document 1, the present applicant has developed a joint structure of a steel segment having sufficient strength against bending and has been put to practical use.

  As shown in FIG. 7, the joint structure of the steel segment described in Patent Document 1 uses a segment 101 in which a joint plate 110 on the segment joint surface is installed only on the ground side of the neutral shaft. The joint plates 110 of the adjacent segments 101 are joined to each other by bolts, and the web 112 and the lower flange 113 of the main girder 111 perpendicular to the direction of the center axis of the tunnel are not shown on the tunnel center side of the neutral axis. It joins by connecting through a contact plate.

JP-A-11-22393

  However, in the conventional joint structure of the steel segment 101, in addition to the connection of the joint plates 110, it is necessary to connect the main girders 111 via a large number of bolts. Compared with the construction of a superior type tunnel), the work may be time-consuming.

  The present invention has been made to solve the above-mentioned problems, and can be connected by the same work as a general tunnel construction, and is sufficient for the bending moment acting on the segment ring. It is an object to propose a segment having a sufficient proof strength and having a reasonable joint structure.

In order to solve the above-mentioned problems, a segment of the present invention is a segment that forms a segment ring by being connected by a plurality of bolts, and is disposed along the circumferential direction of the tunnel. A plurality of girders arranged side by side with a predetermined interval with respect to the axial direction, a plurality of joint portions arranged along the segment joint surface, and vertical ribs laid between the girders, An outer shell plate that is laterally disposed on the plurality of girders and covers an outer surface, and the joint portions are arranged at intervals in the tunnel axis direction, each connected to an end portion of the girders , during the joint portions, an opening portion is formed, waterproof joint plate for shielding the opening is characterized that you have been provided.

According to such a segment, since the joint portion configured to have a necessary thickness with respect to the stress transmitted through the bolt is disposed only at a necessary portion, the structure is secured while ensuring the necessary rigidity in the joint structure. It is possible to omit unnecessary portions. Further, the segments are connected to each other by bolts using a joint portion, and the same work as that for assembling the segments in a general tunnel is sufficient, so that the workability is excellent.
The segment according to the present invention may be used, for example, as a primary lining of a shield tunnel, or may be used as a liner in a mountain tunnel, and the tunnel construction method to be used is not limited. .

In addition, the segment is between between the joint part, because have openings, reducing the amount of members in the joint structure, together with reducing the weight of the segment, the reduction of material costs is possible .

Further, in the segment, the order waterproof joint plate for shielding an opening is provided, in a tunnel that is expected groundwater volume is large, it is that possible to ensure the water-blocking.

  According to the segment of the present invention, since it can be connected to each other by the same work as the construction of a general tunnel and has a joint structure having sufficient strength against bending stress acting on the tunnel, It is possible to easily and inexpensively construct a tunnel consisting of a superior stress state.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. In the description, the same reference numerals are used for the same elements, and redundant descriptions are omitted.
In addition, this embodiment demonstrates the case where what is called a steel segment comprised by combining a steel member as a segment is used.

Segment 1 according to the present embodiment, as shown in FIG. 1, there forms a segment ring by being more connected via the joint bolt (not shown) (volts), along the circumferential direction T _A of the tunnel the two main girder (digit) 11, 11 which are arranged with a predetermined gap d to the axial direction T _B of the tunnel while being disposed Te, the main digit tunnel circumferential direction T _a It is comprised with the joint board (joint part) 12, 12, ... arrange | positioned one by one along each segment joint surface _JS , _JS formed in an edge part.

Moreover, the joint plate 13 for water stop is each arrange | positioned in the state laid laterally by a pair of joint plates 12 and 12 at the segment joint surface _JS . The outer surface of the natural ground side of the segment 1 is covered with an outer shell plate 15.
Further, the segment 1 is formed in an arc shape in accordance with the cross-sectional shape of the tunnel, and four vertical ribs 14, 14,... It is arranged along the direction.

As shown in FIG. 2, the segment 1 according to the present embodiment is configured in such a manner that a structure K is constructed by connecting and extending the tunnels T by cutting between the two adjacent tunnels T and T. The segment ring R is preferably used.
With the construction of the structure K, the segment ring R has a circular shape with a part cut off on the other tunnel T side.

  As shown in FIG. 3A, in the state where the segment rings R and R provided in an annulus form an annular shape, when the upper loads P and P such as earth loads act, the segment ring R has an excellent axial force. In order to maintain the stress state of the mold, the bending moment M1 acting on the segment ring R is small. However, as shown in FIG. 3B, when a part of the segment ring R1 is cut out and the segment ring R1 becomes a circle, the segment ring R1 becomes a bending-dominant stress state and acts on the segment ring R1. The bending moment M2 to be increased is larger than the bending moment M1 of the segment ring R (FIG. 3A) formed in an annular shape.

As described above, since a bending stress is generated in the segment ring R, a tensile force is generated in the joint bolt at the segment joint surface _JS of the segments 1, so that the joint plate 12 has a sufficient yield strength against the tensile force. It is necessary to have a member thickness that expresses.

The main girder 11, as shown in FIG. 1, are disposed back and forth relative to the tunnel axis T _B of segment 1 so as to face the ring joint surface J _R. The main girder 11 is a steel member formed in an arc shape along the cross-sectional shape of the tunnel. In the present embodiment, the main girder 11 is constituted by a steel plate having a predetermined thickness. Further, the main girder 11 is formed with a plurality of bolt holes 11a, 11a,... At predetermined intervals, and can be connected to the front and rear segment rings via connection bolts (not shown).

The main girder 11 is made of a material having sufficient strength against bending moment and axial force generated in the segment ring R and having sufficient strength to function as a joint member on the ring joint surface _JR . Shall be composed.
In addition, the material, the shape dimension, etc. which comprise the main girder 11 are not limited, For example, you may comprise with various shape steels, such as H-section steel, a member made from fiber reinforced concrete. Moreover, the shape, arrangement | positioning, and number of places of the bolt hole 11a formed in the main beam 11 are not limited, It sets suitably according to the shape dimension, arrangement | positioning, etc. of a connection bolt required for the connection of segment ring R. That's fine. Moreover, although this embodiment demonstrated the case where the main girder 11 was used as a joint member of the ring joint surface _JR , it cannot be overemphasized that a joint member may be provided separately from the main girder 11. FIG.

  As shown in FIGS. 1 and 4, joint plates 12 and 12 are integrally fixed to both ends of the main beam 11, respectively.

As shown in FIG. 4, the joint plate 12 attached to one main girder 11 is disposed along the segment joint surface _JS , and between the joint plate 12 attached to the other main girder 11. , while forming the opening 12a along the tunnel axis T _B, it is connected to the end of one of the main girder 11.

  The joint plate 12 according to the present embodiment is a steel plate formed in a rectangular shape, and as shown in FIG. 3 (b), a segment formed in a circular shape by cutting out a part of the segment ring R. The bending moment M2 acting on the ring R1 is configured to have a thickness having a necessary yield strength. In addition, the material which comprises the joint board 12 is not limited to a steel plate, What is necessary is just to select from a well-known material suitably, for example using a fiber reinforced concrete member. Further, the shape of the joint plate 12 is not limited and can be set as appropriate.

  The joint plate 12 is formed with three bolt holes 12b through which joint bolts (not shown) can be inserted, and can be connected to other adjacent segments. In addition, the shape, arrangement | positioning, and number of places of the bolt hole 12b are not limited, What is necessary is just to set suitably according to the stress state which acts on the segment ring R, the structure of the joint bolt to be used, etc.

As shown in FIGS. 1 and 4, the segment joint surface J _S of the segment 1, waterproof joint plate 13 are laterally disposed to cover the surface of the joint plate 12 and 12, the opening 12a is shielded Has been. Bolt holes 13a, 13a, and 13a are formed in the water stop joint plate 13 at locations corresponding to the bolt holes 12b of the joint plate 12, so that joint bolts can be inserted when connecting to other adjacent segments. It is configured. In addition, the shape, arrangement | positioning, and number of places of the bolt hole 13a are not limited, If it sets suitably according to the stress state which acts on the segment ring R, the repulsive force of a water stop material, the structure of the joint bolt to be used, etc. Good. Further, in this embodiment, the water stop joint plate 13 is disposed horizontally so as to cover the outer surface of the joint plate 12 (the surface on the other adjacent segment 1 side). It may be installed side by side so as to cover the side surface, or may be arranged so as to shield the opening 12a between the joint plates 12, and if water stop can be secured, the water stop joint plate 13 can be secured. The installation location of is not limited.

Longitudinal ribs 14 is a steel member that is installed between the main beam 11 to each other is a member for transmitting during tunnel construction, the stress of the tunnel axis T _B.
In the present embodiment, four plate-like members are arranged as the vertical ribs 14 at a predetermined interval with respect to one segment 1, but the material, number, arrangement pitch, and the like constituting the vertical ribs 14 are limited. What is necessary is just to set suitably.

  The outer shell plate 15 is made of a steel plate or the like that has been processed into an arc shape, and is provided on the main girders 11 and 11 so as to cover the outer surface of the segment 1. The shape of the outer shell plate 15 is not limited, and may be set as appropriate according to the planned cross-sectional shape of the tunnel. Moreover, the plate | board thickness of the steel plate which comprises the outer shell board 15 will not be limited if it can express sufficient proof stress with respect to the stress which acts by earth pressure, groundwater pressure, etc. FIG. Furthermore, the material constituting the outer shell plate 15 is not limited to a steel plate, and can be appropriately selected from known materials such as a fiber reinforced concrete.

  As described above, according to the segment 1 according to the present embodiment, by arranging the joint portion 12 configured to have a necessary thickness with respect to the stress transmitted through the joint bolt at a necessary position, the bending dominant type is achieved. It is possible to construct the segment ring R having the proof stress necessary for the segment ring R. Further, the segments 1 are connected to each other by joint bolts using the joint plate 12, and the same work as the assembly of the segments in a general tunnel is sufficient, so that the workability is excellent.

Since the joint plate 12 having a necessary plate thickness with respect to the bending moment acting on the segment joint surface _JS is disposed only at a necessary position with a gap in a state where the opening 12a is formed, Compared with a general segment in which a joint plate having a uniform plate thickness is arranged on the entire segment joint surface _JS , the amount of steel material can be reduced. As a result, the material cost can be reduced and construction can be performed at a low cost, and the weight of the segment 1 can be reduced. Therefore, handling becomes easy and workability is improved. Particularly when wide segments are used, the effect of reducing the weight of the joint plate becomes significant.

  Further, since the position of the bolt hole 12b is sufficiently moved toward the main beam 11, only the shearing force due to the tensile force of the joint bolt is generated at the joint portion between the main beam 11 and the joint plate 12, and therefore the influence of the bending moment. Therefore, it is possible to ignore the bending moment in the weak axis direction of the main girder 11 in the design. As a result, it is not necessary to consider the biaxial stress state in the design of the main girder 11, The cross section of the beam 11 can be reduced. Therefore, the weight of the segment 1 can be reduced and the material cost can be reduced.

Since the opening 12a formed between the joint plates 12 is shielded by the water stop joint plate 13, it is possible to construct a segment ring R excellent in water stop.
Further, due to the arrangement of the main beam 11 and the vertical ribs 14, it has a necessary strength against the thrust of the shield machine.

Next, with respect to the segment according to the present invention, the result of verifying the influence of the shape of the joint plate arranged with a gap on the deformation of the segment will be described with reference to FIG. 5 and FIG. .
This verification is performed by performing FEM analysis using a three-dimensional solid model.

  In the analysis, verification was performed in three stages according to the magnitude of the tensile force generated in the joint bolts arranged at both ends in the tunnel axis direction on the segment joint surface by applying a bending moment to the segment ring. Each stage used for the analysis was STEP1 when the bolt was tightened, STEP2 when the bolt allowable tensile force was generated, and STEP3 when the bolt yielded.

  FIGS. 5A and 5B show the models of segments 1 and 1 ′ used in this verification. As shown in FIG. 5 (a), in the segment 1 'of the comparative example according to this verification, a plate material having the same thickness is disposed as a joint plate 12' in the entire range of the segment joint surface. On the other hand, as shown in FIG. 5B, in the verification model, the two joint plates 12 and 12 are arranged on the surface of the segment joint surface with the opening 12a formed at intervals. A water stop joint plate 13 is disposed.

  In the comparative example, a steel plate having a thickness of 76 mm is used for the joint plate 12 ′ of the segment 1 ′. On the other hand, in the segment 1 in the verification model, a steel plate having a thickness of 64 mm is used as the joint plate 12, and the same thickness (76 mm) as the joint plate 1 ′ of the comparative example is obtained by adding the plate thickness 12 mm of the joint plate 13 for water stoppage. ) Was formed.

  When a bending moment is applied to the segment ring, a tensile force is applied to the joint bolt. Therefore, as shown in FIGS. 5C and 5D, the segment is deformed in the direction away from the other segments in the joint plate 12. As α occurs, the main girder 11 connected to the joint plate 12 undergoes deformation β that is distorted inward.

  As shown in FIGS. 6A and 6B, in STEP 2, the deformation amount α of the joint plate 12 ′ generated in the comparative example was 0.68 mm, and the deformation amount β ′ of the main beam 11 was 0.22 mm. On the other hand, the deformation amount α of the joint plate 12 and the deformation amount β of the main girder 11 generated in the example were 0.74 mm and 0.25 mm, respectively. Therefore, the difference in deformation amount of the joint plate in STEP 2 is 0.06 mm, and the difference in deformation amount of the main girder is 0.03 mm.

  As shown in FIGS. 6A and 6B, the deformation amount α ′ of the joint plate 12 ′ of the comparative example in STEP 3 and the deformation amount β ′ of the main girder 11 are 1.94 mm and 0.58 mm, respectively. In contrast, the deformation amount α of the joint plate 12 and the deformation amount β of the main girder 11 were 2.11 mm and 0.70 mm, respectively. Therefore, the difference in deformation amount of the joint plate in STEP 3 is 0.07 mm, and the difference in deformation amount of the main girder is 0.12 mm.

  As described above, on the segment joint surface, as a joint plate 12, a plate material having a uniform thickness is disposed between the main girders 11 (comparative example), and two joint plates 12 having the configuration of the present invention, There was no significant difference in the amount of deformation between the case of disposing 12 apart (Example), and no clear difference in the stress distribution of the segments. Therefore, it is possible to arrange the joint plates (joint portions) 12 and 12 with an interval in the axial direction of the tunnel, forming an opening between the joint portions, or reducing the plate thickness between the joint portions. Proved to be possible.

As mentioned above, although preferred embodiment was described about this invention, this invention is not limited to the said embodiment, A design change is possible suitably in the range which does not deviate from the meaning of this invention.
For example, in the above-described embodiment, two joint plates are arranged at intervals in a state having an opening as a joint portion disposed on the segment joint surface. You may form integrally with a board | plate material. In other words, a segment joint portion of a segment is formed by placing a single plate material with a thickness corresponding to the joint portion and a thin plate other than that between the pair of main girders. Also good. Thereby, in the said embodiment, it becomes possible to comprise integrally the coupling board comprised by combining another member, and the joint board for water stop.

  Moreover, although the said embodiment demonstrated the segment in which two main digits are arrange | positioned, the number of the main digits arrange | positioned in a segment is not limited, and three or more may be arrange | positioned. In this case, the structure which provides a joint board in the main girder arrange | positioned in an intermediate part may be sufficient. An auxiliary girder may be provided in addition to the main girder, and a joint plate may be connected to the end of this auxiliary girder.

  Moreover, in the said embodiment, although what comprised the main girder and the joint board by another member shall be connected mutually, you may comprise a joint part and a main girder by integral molding. Moreover, the joining method of a joint board and a main girder is not limited, What is necessary is just to perform by a well-known means suitably.

  Further, the water stop joint plate may be disposed as necessary, and may be omitted in a tunnel or the like in which a secondary lining is provided separately.

  Needless to say, the cross-sectional shape of the segment ring is not limited to a circular shape, and can be set as appropriate according to the application of the tunnel.

It is a perspective view which shows the segment which concerns on suitable embodiment of this invention. It is sectional drawing which shows the outline | summary of the tunnel which concerns on suitable embodiment of this invention. It is a bending moment figure which shows the stress state of the tunnel shown in FIG. 2, Comprising: (a) shows the case where a segment ring is formed in the annular | circular shape, (b) is the case where the segment ring is formed in a missing circle shape Indicates. It is an expansion perspective view which shows a part of segment shown in FIG. It is a figure which shows the verification result of the segment which concerns on this invention, Comprising: (a) And (b) is an analytical model figure, (c) And (d) is a deformation | transformation figure of the analytical model shown to (a) and (b), respectively. Indicates. It is a graph which shows the verification result of FIG. It is a perspective view which shows the conventional segment.

Explanation of symbols

1 segment 11 main digit (digit)
12 Joint plate (joint part)
13 Joint plate for water stop R Segment ring J _S segment joint surface TA Circumferential direction of _A tunnel T Axial direction of _B tunnel

Claims (1)

A segment that forms a segment ring by being connected by a plurality of bolts,
A plurality of girders arranged along the circumferential direction of the tunnel and arranged in parallel at a predetermined interval with respect to the axial direction of the tunnel;
A plurality of joint portions arranged along the segment joint surface;
Vertical ribs erected between the beams,
An outer shell plate that is laterally disposed on the plurality of girders and covers an outer surface ,
The joints are arranged at intervals in the axial direction of the tunnel, each connected to the end of the beam ;
While an opening is formed between the joints ,
A segment having a water stop joint plate for shielding the opening.

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