JP4279284B2 - Segment shape retention device - Google Patents

Description

  The present invention relates to a shape retaining device for a segment that is assembled with excavation in a shield method.

  In the shield method that builds a tunnel in the ground using a shield machine, a segment consisting of a plurality of pieces in the circumferential direction is assembled on the inner surface of the skin plate of the shield machine as the digging is carried out. When assembling this segment, deformation occurs in the segment due to external earth pressure or its own weight, which often hinders the assembly (connection) of the next segment. A holding device is being used.

  The basic structure of the shape holding device is such that a pair of left and right columns that can be expanded and contracted in a vertical direction are arranged on a support frame that protrudes rearward from the shield machine main body so as to be movable in the tunnel direction. The upper holding portion is provided with an upper holding beam along the cross-sectional shape at the upper end portion thereof, and the lower holding beam is provided at the lower end portion (hereinafter referred to as a vertically extending shape holding device). By holding the upper holding beam and lower holding beam against the inner surface of the segment, the vertical force applied to the segment by vertical earth pressure or its own weight is supported to hold the segment in a properly assembled state and prevent deformation It is.

In recent years, as shown in Patent Document 1 below, in addition to the support in the vertical direction, a horizontal member that can be expanded and contracted is provided on both sides in the horizontal direction, and a left holding beam and a right holding beam are provided at the tip of the horizontal member. There has also been proposed a shape holding device (hereinafter referred to as an up-and-down and left-right expanded shape holding device) that supports horizontal earth pressure and water pressure.
Japanese Patent Application Laid-Open No. 8-109796

  However, the conventional shape holding device has the following problems.

(1) The conventional segment shape holding device installed in the segment occupies most of the empty space in the tunnel, often resulting in obstacles such as segment transportation and worker movement.

(2) As shown in FIG. 2 of the above-mentioned Patent Document 1, the shape maintaining device is usually located one ring behind the front row segment in order to avoid interference with the erection device for assembling the segment and the assembly scaffold. It must be installed in the previously assembled segment that is positioned, and the segment adjacent to the segment that assembles a new segment is not held by the shape holding device. As a result, the assembly work of a newly assembled segment may be hindered. This tendency is particularly prominent when the large-diameter segment with its own weight increases or when the influence of earth pressure is large.

(3) None of the above-described vertically expanded shape holding device and the up / down and left / right expanded shape holding device can cope with lifting. In general, in shield digging, about half of the foremost segment goes out of the shield machine and receives buoyancy with the propulsion jack pushed out. At this time, since the backing material is filled on the back side of the segment outside the skin plate, the entire circumference is constrained to some extent, but the initial strength of the backing injection material is small, so it is supported by the shape holding device. There is concern about the lift (displacement) of the frontmost segment that has not been made. Further, in the case of a large-diameter segment, there is a possibility that the segment will be deformed due to the difference in water pressure between the upper and lower sides, which may hinder the bolt connection of the next segment.

(4) A predetermined gap is formed between the skin plate of the shield machine and the segment to reduce friction. For this reason, the segment may slip off inside the skin plate due to its own weight.

  Therefore, the main object of the present invention is to secure a sufficient space inside the segment, and to hold the segment immediately after the assembly of the segment. It is an object of the present invention to provide a segment shape holding device that can eliminate all the problems such as slipping off due to slack.

In order to solve the above-mentioned problem, the present invention according to claim 1 is the tunnel center side at an appropriate interval in the circumferential direction on the inner surface side and the rear side position of the skin plate as the outer shell of the shield machine. as well as arranging a plurality retractably or expansion and contraction freely segments holder toward, the segment carrier is a tandemly two rows arranged in a tunnel direction the segment holder groups arranged in the circumferential direction as a line At the same time, when the front segment holder row is positioned at the approximate center of the front row segment, the rear segment holder row is positioned closer to the face of the next row segment, and immediately after the assembly of the front row segment is completed. , Even if the front row segment and the previously assembled segment are held together and the shield machine moves forward, the rear segment holder row is now the front row segment Holding, shape-retaining device of a segment, characterized in that the front segment holding column at substantially the center of the next assembled segments are adapted to position is provided.

  In the first aspect of the present invention, a plurality of the segment holders are arranged along the circumferential direction of the skin plate, and are supported from multiple points on the outer periphery side of the segment. Therefore, since there is no shape holding device inside the segment, a sufficient space is secured in the tunnel. In addition, since interference with the erector device or the assembly scaffold does not cause any problems, the segment immediately after assembly can be immediately supported. Further, as a result of immediately supporting the segment immediately after assembly, all the problems such as floating, deformation due to water pressure difference, and slippage due to its own weight in the skin plate can be solved.

  The segment holders are arranged in two rows vertically in the tunnel direction with a group of segment holders arranged in the circumferential direction as one row, and the front segment holder row is located at the center of the foremost segment. The segment holder row is arranged so as to be positioned on the side closer to the face of the next row segment. That is, the interval L between the front segment holding body row and the rear segment holding body row is set to 1/2 + α or more of the segment width and within the segment width, and immediately after the assembly of the front row segment is completed, it is assembled to the front row segment and the previous time. Even if the shield machine is drilled after holding the segments together, the rear segment holder row now holds the front row segment, and the front segment holding row is positioned approximately in the center of the next assembled segment. Become.

  As the present invention according to claim 2, between the front segment holding body row and the rear segment holding body row, the front segment holding body and the rear segment holding body located on the tunnel longitudinal direction line have an integral unit structure, The segment shape retaining device according to claim 1, wherein the unit structure is replaceable.

  According to a third aspect of the present invention, the segment holder is an expansion mat or jack that can be moved forward and backward or expanded and contracted toward the center of the tunnel by a fluid such as liquid, gas, or oil. A segment shape holding device according to any one of the above is provided.

  As a fourth aspect of the present invention, the expansion mat is relatively disposed on the circumferential upper region side of the skin plate, and the jack is disposed relatively on the circumferential lower region side. The shape retaining device for a segment described in 1) is provided.

  As a fifth aspect of the present invention according to any one of the first to fourth aspects, the segment abutting portion of the segment holder is subjected to a friction reducing process for smooth sliding or provided with a wear reducing member. The shape retaining device for a segment described in 1) is provided.

  As described above, according to the present invention, a sufficient space can be secured inside the segment, and the segment can be held immediately after the assembly of the segment. At the same time, it is possible to solve all the problems such as floating, deformation due to water pressure difference, and slipping due to its own weight in the skin plate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view of the shield machine 1, and FIG. 2 is a view taken along the line II-II in FIG.

  The shield machine 1 shown in the figure is of a muddy water pressurization type, and a cutter chamber 5 is defined between a partition wall 3 provided at the front end of the shield body 2 and a cutter head 4. The mud pipe 6 and the mud pipe 7 are opened to face each other. On the other hand, a segment assembling device 10 (an erector device) is disposed on the rear side in the skin plate 8 serving as an outer shell of the shield machine 1, and is composed of a plurality of pieces in the circumferential direction on the inner surface of the skin plate 8 as it advances. The segment 11 is assembled in a ring shape and lining is performed. Reference numeral 9 denotes a shield jack for propelling the shield body 2.

  In the shield machine 1, on the inner surface side of the skin plate 8 and on the rear side position, the segment holding body 12 that can be advanced / retracted / expanded / retracted toward the tunnel center side at an appropriate interval in the circumferential direction. , 13... Are provided, and a shape holding device is provided for supporting the segments from the outer periphery at multiple points. The segment shape holding device according to the present invention is not limited to the muddy water pressurization type, but is applied to various shield machines such as a muddy water type, earth pressure type, and mud pressure type.

Hereinafter, the segment shape holding device will be described in detail.
As the segment holder, for example, an expansion mat 12 or a hydraulic (or pneumatic) jack 13 that can be expanded and contracted by a fluid such as liquid, gas, oil, etc. is used. The assembled segment 11 is supported at multiple points from the outer surface side to prevent the segment 11 from being deformed by an external force due to earth pressure, its own weight, and water pressure, and to prevent a lift and a drop due to its own weight.

  In this case, as shown in the figure, the segment holding body preferably has the expansion mats 12, 12,... Relatively disposed on the circumferential upper region side of the skin plate 8 to relatively move the circumferential lower region. It is desirable to arrange the hydraulic jacks 13 on the side. It is possible to easily adjust the position of the segment 11 by disposing the hydraulic jacks 13, 13,... That can easily move the supported body by adjusting the stroke on the lower region side. Of course, the expansion mats 12, 12,... Or the hydraulic jacks 13, 13,.

As shown in FIG. 1, the segment holders are arranged in two rows vertically in the tunnel direction with the segment holder groups 12, 13... Arranged in the circumferential direction as one row, and the front segment holder row 14. It is arranged so as when located in substantially the center of the front row segments 11 _1, the rear segment holding element row 15 is positioned next to the column segment 11 _{and second} working face near side. That is, the distance L between the front segment holding element row 14 and the rear segment holding element row 15 is within 1/2 + alpha or segment the segment width wide, immediately after completion of assembly of the front row segments 11 _1, the front row segment 11 holding together ₁ and the segment 11 ₂ assembled to last even after the shield machine 1 and excavation, turn rear segment carrier column 15 holds the front row segments 11 _1, segment are then assembled The front segment holding row 14 is positioned substantially at the center.

  For example, as shown in FIG. 3, the expansion mat 12 is provided with a concave portion 8a on the inner surface side of the skin plate 8, and can be accommodated in the concave portion 8a when contracted. The fixing bracket 21 is integrally provided on the peripheral portion of the inflatable bag body, and the fixing bracket 21 is fixed by the fixing bolt 16, and the discharge port of the flow path 17 formed in the skin plate 8 is connected to the discharge port. It faces the inner space of the expansion mat 12 and can be expanded toward the center of the tunnel by supplying or extracting a working fluid such as liquid or gas.

  As shown in FIG. 4, the expansion mat 12 may be provided with an elastic stretchable sheet 18 so as to close the opening surface of the recess 8a to prevent wear. When the expansion mat 12 is operated, the elastic stretchable sheet 18 swells together with the expansion mat 12 as shown in FIG.

  On the other hand, as shown in FIG. 5, the hydraulic jack 13 is provided with a recess 8a on the inner surface side of the skin plate 8 and can be accommodated in the recess 8a when contracted. The piston is extended to the tunnel center side by the hydraulic oil supplied from the passage 17 so as to press and hold the segment 11.

  As shown in FIG. 6, the segment holder is rearward from the front segment holder 12 arranged between the front segment holder row 14 and the rear segment holder row 15 on the tunnel longitudinal direction line. The concave segment 8b is continuous until the side segment holding body 12 is disposed, and the front segment holding body 12 and the rear segment holding body 12 are accommodated inside the box 19 to form an integral unit structure. It is desirable to make this unit structure replaceable. It should be noted that the same structure can be adopted for the unitization of the hydraulic jack.

  Further, since the segment holders 12 and 13 generate friction on the outer surface of the segment 11 when the shield machine 1 is dug, the segment holders 12 and 13 smoothly slide on the segment abutting portions. It is desirable to apply a friction reducing process to provide a wear reducing member. As the former friction reduction processing, for example, a dimple-like protrusion is provided on the segment abutting surface of the expansion mat 12 or the hydraulic jack 13 to reduce the contact area, or a friction reducing material such as tetrafluoroethylene resin is coated. As the latter friction reducing member, for example, a tetrafluoroethylene resin coated plate is provided on the segment abutting surface of the expansion mat 12 or the hydraulic jack 13, as shown in FIG. For example, a method of providing the bearing device 20 can be used.

  By the way, in the segment shape holding device according to the present invention, a plurality of segment holders that can be advanced and retracted or expanded and contracted toward the center of the tunnel are disposed at appropriate intervals in the circumferential direction. In the case of the mat 12, the mat 12 may be provided so as to be continuous in the circumferential direction. In the above example, the circular cross-section tunnel has been described as an object. However, the target tunnel cross-sectional shape may be a shape other than a circle, such as an ellipse or a horseshoe.

It is a longitudinal cross-sectional view of the shield machine 1. It is the II-II arrow directional view of FIG. (A) is an accommodation state figure of the expansion mat 12 which comprises a segment shape holding body, (B) is a segment support state figure. (A) is an accommodation state figure, (B) is a segment support state figure concerning the modification of the expansion mat 12 which comprises a segment shape holding body. (A) of the hydraulic jack which comprises a segment shape holding body is an accommodation state figure, (B) is a segment support state figure. It is a figure which shows the united structure example of the front segment holding body 12 and the rear segment holding body 12 which are located on a tunnel longitudinal direction line. It is a friction reduction member arrangement | positioning schematic diagram consisting of the bearing apparatus 20 with respect to a segment holding body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Shield machine, 2 ... Shield main body, 3 ... Bulkhead, 4 ... Cutter head, 5 ... Cutter chamber, 8 ... Skin plate, 10 ... Elector apparatus, 11 ... Segment, 11 ₁ ... Front row segment, 11 ₂ ... Next row Segment: 12 ... Expansion mat, 13 ... Hydraulic jack, 14 ... Front segment holder row, 15 ... Rear segment holder row

Claims (5)

A plurality of segment holders that can move forward and backward or expand and contract toward the center of the tunnel at an appropriate interval in the circumferential direction on the inner surface side of the skin plate that is the outer shell of the shield machine and at the rear side position. The segment holders are arranged in two rows vertically in the tunnel direction with the group of segment holders arranged in the circumferential direction as one row , and the front segment holder row is positioned substantially at the center of the frontmost segment. The rear segment holder row is in a relative positional relationship that is located closer to the face of the next row segment, and immediately after the assembly of the front row segment is completed, the front row segment and the previously assembled segment are held together, After that, even if the shield machine digs up, the rear segment holder row holds the front row segment, and the front side is approximately at the center of the next assembled segment. Shape-retaining device segment, wherein the segment holding column is adapted to position.   Between the front segment holding body row and the rear segment holding body row, the front segment holding body and the rear segment holding body which are located on the tunnel longitudinal direction line have an integral unit structure, and this unit structure can be replaced. The segment shape holding device according to claim 1.   The segment shape holding device according to any one of claims 1 and 2, wherein the segment holding body is an expansion mat or a jack that can be advanced and retracted or expanded and contracted toward a tunnel center side by a fluid such as liquid, gas, and oil. apparatus.   The segment shape holding device according to any one of claims 1 to 3, wherein the expansion mat is relatively disposed on the circumferential upper region side of the skin plate, and a jack is relatively disposed on the circumferential lower region side.   The segment shape holding device according to any one of claims 1 to 4, wherein the segment abutting portion of the segment holder is subjected to a friction reducing process for smooth sliding or provided with a wear reducing member.

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