JP4686778B2 - Segment shape holding device - Google Patents

Description

  The present invention relates to an apparatus for maintaining the shape of a segment assembled in a ring shape along the inner periphery of a tunnel.

  A shield machine excavates a natural ground with a cutter provided at the front part of a shield frame, and constructs a tunnel by sequentially assembling segments into a ring shape behind the excavated ground.

  When the assembled segment is subjected to earth pressure, a stress (axial force) in the tunnel circumferential direction is generated in the segment (see reference numeral Fr in FIG. 5), and the shape of the assembled segment is maintained by the action of this stress. It has become.

  By the way, the assembly of the segments is performed inside the shield frame of the shield machine. There is a case in which earth pressure is not applied to the segment assembled inside the shield frame, and the segment is deformed by its own weight or the like, which hinders assembly of a new segment.

  Therefore, by inserting a wire into the segment in the tunnel circumferential direction and applying tension to the inserted wire, stress in the tunnel circumferential direction (prestress) is applied to the segment (for example, Patent Document 1 and (See 2nd grade).

JP 2003-269099 A Japanese Patent No. 3308916

  However, in the case where tension is applied to the wire inserted into the segment, there is a problem that the frictional resistance when inserting the wire into the segment is large, and much labor is required to insert the wire into the segment.

  Moreover, in order to insert a wire into a segment, a hole must be formed in the segment, which causes a problem of increasing the manufacturing cost of the segment.

  Accordingly, an object of the present invention is to provide a segment shape holding device that can easily apply a stress in the tunnel circumferential direction to a segment without inserting a wire into the segment.

  Another object of the present invention is to provide a segment shape holding device that does not increase the manufacturing cost of the segment.

  In order to achieve the above object, the present invention is an apparatus for maintaining the shape of a segment assembled in a ring shape along the inner periphery of a tunnel, and for applying a stress in the circumferential direction of the tunnel to the segment. Is provided with a stress applying means for pulling inwardly in the tunnel radial direction at the inner periphery thereof.

  Here, the stress applying means includes a bracket attached to the inner peripheral surface of the segment, an annular wire bridged between the brackets adjacent in the circumferential direction of the tunnel, and a tension applying means for applying tension to the wire. You may have.

  Further, a holding unit for holding the wire along the circumferential direction of the tunnel, and an axial direction moving unit for moving the holding unit in the tunnel axis direction may be further provided.

  A part of the wire may be replaced with a bar.

  According to the present invention, there is an excellent effect that stress in the tunnel circumferential direction can be easily applied to a segment without inserting a wire into the segment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a side sectional view of a shield machine using a segment shape holding device according to an embodiment of the present invention. 2 is a cross-sectional view taken along line II-II in FIG. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

  As shown in FIG. 1, the shield machine 1 includes a cylindrical shield frame 2 and a cutter (not shown) rotatably provided at the front portion of the shield frame 2. At the rear of the shield frame 2, there are an erector (not shown) for assembling a segment 3 in a ring shape in a hole excavated by a cutter, and a plurality of the inner periphery of the shield frame 2 with a predetermined interval. A shield jack (not shown) is provided for taking the reaction force on the segment 3 and propelling the shield frame 2.

  A tail seal 4 for sealing a gap between the shield frame 2 and the segment 3 is provided at the rear end portion (tail seal portion 2 a) of the shield frame 2.

  In the present embodiment, the segments 3 adjacent to each other in the tunnel circumferential direction or the axial direction are connected by connecting adjacent portions of the segments 3 with bolts. A seal member (not shown) for water stop is provided between the segments 3 adjacent to each other in the tunnel circumferential direction and the axial direction.

  The segment shape holding device (tension type segment shape holding device) 10 of this embodiment is for assembling a ring 3 along the inner periphery of the tunnel to hold the shape of the segment 3 located in the shield frame 2 in a perfect circle. It is.

  As shown in FIG. 1 to FIG. 4, the segment shape holding device 10 tunnels the segment 3 at its inner peripheral portion in order to apply a stress (axial force) Fr (see FIG. 5) in the tunnel circumferential direction to the segment 3. A stress applying means 11 for pulling inward in the radial direction is provided.

  The stress applying means 11 of the present embodiment includes a bracket 12 attached to the inner peripheral surface of the segment 3, an annular wire 13 spanned between the brackets 12 of the segment 3 adjacent in the tunnel circumferential direction, and a predetermined amount on the wire 13. Tension applying means 14 for applying tension (tension).

  In the present embodiment, the bracket 12 is attached to the approximate center of the inner peripheral surface of the segment 3.

  The brackets 12 are preferably arranged at a substantially constant interval in the tunnel circumferential direction. In other words, the brackets 12 are preferably arranged at equal intervals in the tunnel circumferential direction. This is because the force of pulling in the tunnel radial direction is applied evenly vertically and horizontally to the segment 3 assembled in a ring shape.

  In this embodiment, the bracket 12 is attached to each segment 3 arranged in the tunnel circumferential direction. Note that the pulling force in the tunnel radial direction may be applied to the segment 3 assembled in a ring shape substantially vertically and horizontally, and the bracket 12 may be attached to some of the segments 3 arranged in the circumferential direction of the tunnel. .

  In the present embodiment, the bracket 12 includes a grip portion 15 that protrudes from substantially the center of the inner peripheral surface of the segment 3, a mounting portion 16 that can be attached to and detached from the grip portion 15, and a wire 13 that is provided integrally with the mounting portion 16. And a ring 17 through which is inserted.

  The gripping portion 15 is formed of a gripping bracket that is used when an erector grips the segment 3 when the segment 3 is assembled, and is attached to the segment 3 in advance. The grip portion 15 needs to be removed after the assembly of the segment 3 is completed, and thus is attached to the segment 3 by screwing.

  A wire 13 is inserted through the ring 17 in advance. In a state where the mounting portion 16 is removed from the gripping portion 15, the ring 17 and the mounting portion 16 are supported by the wire 13.

  In this embodiment, a part of the wire 13 between the brackets 12 adjacent in the tunnel circumferential direction is replaced with a bar 18 having higher rigidity than the wire 13. By doing in this way, when the wire 13 is cut | disconnected, it can prevent that the wire 13 jumps largely.

  In the present embodiment, a jack 19 (in this embodiment, a hydraulic jack) is used as the tension applying means 14. In the jack 19, the cylinder tube 20 is fixed to one end side of the wire 13, and the rod 21 is fixed to the other end side of the wire 13. By retracting the jack 19, the wire 13 stretched between the brackets 12 is pulled and tension is applied to the wire 13.

  The segment shape holding device 10 of the present embodiment has a holding means 22 for holding the wire 13 along the tunnel circumferential direction, and for moving the holding means 22 in the tunnel axis direction (see arrow A in FIG. 1). An axial movement means 23 is further provided.

  The holding means 22 of the present embodiment mainly includes a fixing member 24 and a rotating member 26 supported on the outer periphery of the fixing member 24 via a slider 25. The fixing member 24 and the rotating member 26 are formed in a substantially C shape when viewed from the front, and the opening is directed downward. The fixing member 24 is supported by a column 28 provided on a carriage 27 described later.

  The rotating member 26 is rotatable with respect to the fixed member 24 by a predetermined opening degree in the tunnel circumferential direction (see arrow B in FIG. 3). The positions of the mounting portion 16 and the ring 17 of the attached bracket 12 can be adjusted.

  A recess 29 is provided on the outer periphery of the rotation member 26 along the circumferential direction of the tunnel. A plate 31 having an insertion hole 30 through which the bar 18 is inserted is spaced apart from the recess 29 by a predetermined interval in the tunnel circumferential direction. Are provided. The bar 18 inserted through the insertion hole 30 of the plate 31 is allowed to move in the longitudinal direction.

  The axial movement means 23 has a carriage 27 that is movable in the tunnel axial direction. The carriage 27 is provided so as to be able to travel on a rail 33 laid on a gantry 32. The gantry 32 is provided in the rear part of the shield frame 2 so as to extend rearward.

  A vertically expandable segment shape holding device 34 is provided at the rear portion of the gantry 32. The vertically expanded segment shape holding device 34 of the present embodiment is for holding the shape of the segment 3 located outside the shield frame 2 (behind the tail seal portion 2a) in a perfect circle. The vertically expandable segment shape holding device 34 has an upper gripper 36 and a lower gripper 37 that move up and down by a jack 35 and is connected to a slide jack 38 attached to the gantry 32.

  Next, the operation of this embodiment will be described with reference to FIG.

  When the segment 3 is assembled in a ring shape, the mounting portion 16 is attached to the grip portion 15 of the bracket 12 attached in advance to the segment 3 as shown in FIG. Thereafter, when the jack 19 is retracted and a predetermined tension T is applied to the wire 13, a force F that pulls the segment 3 inward in the tunnel radial direction is generated. By the action of this force F, a stress Fr in the tunnel circumferential direction is applied to the segment 3, and the shape of the segment 3 assembled in a ring shape is held in a perfect circle. Therefore, the segment 3 assembled in a ring shape can be prevented from being deformed by its own weight or the like, and the assembly of a new segment 3 is not hindered.

  Further, by applying a stress Fr in the tunnel circumferential direction to the segment 3 by the segment shape holding device 10, the seal member interposed between the segments 3 adjacent in the tunnel circumferential direction can be crushed, and the water stop is further strengthened. Can be done.

  When the shield machine 1 is dug, the carriage 27 is left behind, and only the gantry 32 follows the shield machine 1. Therefore, the stress applying means 11 (the bracket 12, the wire 13, the bar 18, and the jack 19) is positioned inward of the segment 3 to which the stress in the circumferential direction of the tunnel is to be applied regardless of the excavation of the shield machine 1. Kept.

  If the shield machine 1 further digs and the segment 3 receives a force from the outside in the tunnel radial direction due to the binding force or earth pressure of the tail seal 4, the bracket 12 (gripping portion 15) is removed from the segment 3. When the segment 3 receives the binding force or earth pressure of the tail seal 4, a stress Fr in the tunnel circumferential direction is applied to the segment 3 by the binding force or earth pressure of the tail seal 4. This is because it is not necessary to apply the stress Fr in the tunnel circumferential direction.

  Then, the carriage 32 is advanced to move the stress applying means 11 (the bracket 12, the wire 13, the bar 18, and the jack 19) forward, and the mounting portion is attached to the grip portion 15 of the bracket 12 attached to the newly assembled segment 3. 16 is attached. And the shape of this newly assembled segment 3 is held in a perfect circle.

  On the other hand, if the segment 3 receives a force from the outside in the tunnel radial direction due to earth pressure, the jack 35 of the vertically expandable segment shape holding device 34 is extended so that the tips of the upper gripper 36 and the lower gripper 37 are connected to the tail seal portion 2a. It is pressed against the segment 3 located behind and fixed. The segment 3 located behind the tail seal portion 2a is supported by the vertically expandable segment shape holding device 34 when the earth pressure is not evenly applied to the segment 3 (when the backing material is not evenly spread). Etc.) to prevent the shape of the segment 3 from maintaining a perfect circle and being lost.

  In short, according to the present embodiment, when the stress in the tunnel circumferential direction is applied to the segment 3, the segment 3 is pulled inward in the tunnel radial direction at the inner circumferential portion thereof, so that the wire 13 is attached to the segment 3. The stress in the tunnel circumferential direction can be easily applied to the segment 3 without insertion.

  Moreover, in this embodiment, since it is not necessary to form the hole for inserting the wire 13 in the segment 3, the manufacturing cost of the segment 3 is not increased.

  Further, according to the present embodiment, the stress applying means 11 includes the bracket 12 attached to the inner peripheral surface of the segment 3, the annular wire 13 spanned between the brackets 12 adjacent in the tunnel circumferential direction, and the wire 13 in tension. Therefore, the segment shape holding device 10 does not occupy the central portion of the shield frame 2 and does not hinder the supply of the segment 3 to the erector.

  Further, according to the present embodiment, the wire 13 is further provided with the holding means 22 for holding the wire 13 along the tunnel circumferential direction, and the axial direction moving means 23 for moving the holding means 22 in the tunnel axis direction. It is not necessary to unfold along the circumferential direction of the tunnel every time the 13 is attached to the segment 12, and the handleability of the wire 13 can be improved.

  Moreover, according to this embodiment, since a part of the wire 13 is replaced with the bar 18, it is possible to prevent the wire 13 from bouncing greatly when the wire 13 is cut.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various other embodiments can be adopted.

  For example, instead of the jack 19, a winch (winding device), a chain block, or the like can be used as the tension applying unit 14.

  Further, the configuration of the bracket 12 is not limited to that described above. For example, the grip portion 15 and the mounting portion 16 of the bracket 12 may be provided integrally, or a sheave (pulley) or the like may be provided integrally with the mounting portion 16 instead of the ring 17.

It is a sectional side view of the shield machine which applied the segment shape holding | maintenance apparatus which concerns on one Embodiment of this invention. It is the II-II sectional view taken on the line of FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2. It is a figure which shows the state which provided the stress of the tunnel circumferential direction to the segment.

Explanation of symbols

3 Segment 10 Segment shape holding device 11 Stress applying means 12 Bracket 13 Wire 14 Tension applying means 18 Bar 22 Holding means 23 Axial moving means

Claims (4)

  An apparatus for maintaining the shape of a segment assembled in a ring shape along the inner periphery of a tunnel, and in order to apply a stress in the tunnel circumferential direction to the segment, A segment shape holding device comprising stress applying means for pulling inward.   The stress applying means includes a bracket attached to the inner peripheral surface of the segment, an annular wire spanned between the brackets adjacent in the tunnel circumferential direction, and tension applying means for applying tension to the wire. The segment shape holding device according to claim 1.   The segment shape holding apparatus according to claim 2, further comprising holding means for holding the wire along the circumferential direction of the tunnel, and axial movement means for moving the holding means in the tunnel axial direction.   The segment shape holding device according to claim 2 or 3, wherein a part of the wire is replaced by a bar.

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