JP4278894B2 - Segment shape retention device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shape retaining device for a segment that is assembled with excavation in a shield method.
[0002]
[Prior art]
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 in use.
[0003]
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.
[0004]
In recent years, as disclosed in JP-A-8-109796, in addition to the support in the vertical direction, a horizontal member that can be expanded and contracted on both sides in the horizontal direction is provided, and a left holding beam and A shape holding device (hereinafter, referred to as an up-and-down and left-right extended shape holding device) that is provided with a right-side holding beam and supports horizontal earth pressure and water pressure has also been proposed.
[0005]
[Problems to be solved by the invention]
However, the conventional shape holding device has the following problems.
[0006]
(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.
[0007]
(2) As shown in FIG. 2 of the above-mentioned Japanese Patent Laid-Open No. 8-109796, the shape holding device is usually more than the front row segment in order to avoid interference with the erection device for assembling the segment and the assembly scaffold. There is no choice but to hold the segment adjacent to the segment for assembling a new segment 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.
[0008]
(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, and hinder the bolt connection of the next segment.
[0009]
(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.
[0010]
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.
[0011]
[Means for Solving the Problems]
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. In a segment shape holding device in which a plurality of segment holders that can be advanced and retracted or expanded and contracted are arranged ,
As the segment holder, an expansion mat that can be moved back and forth or expanded and contracted toward the center of the tunnel by a fluid such as liquid, gas, oil or the like is relatively disposed on the circumferential upper region side of the skin plate. In addition, a segment shape holding device is provided in which a hydraulic jack is disposed on the lower side in the circumferential direction .
[0012]
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.
[0013]
As the segment holder, an expansion mat that can be moved back and forth or expanded and contracted toward the center of the tunnel by a fluid such as liquid, gas, oil or the like is relatively disposed on the circumferential upper region side of the skin plate. In particular, it is preferable to arrange a hydraulic jack on the circumferential lower region side.
[0014]
As the present invention according to claim 2, the segment abutment of the segments holder, the segments of claim 1 Symbol mounting is provided with a friction-reducing treatment performed or wear reduction member for facilitating sliding A shape holding device is provided.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
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.
[0016]
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.
[0017]
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.
[0018]
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.
[0019]
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,.
[0020]
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.
[0021]
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.
[0022]
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.
[0023]
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.
[0024]
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 that this unit structure be replaceable. It should be noted that the same structure can be adopted for the unitization of the hydraulic jack.
[0025]
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.
[0026]
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.
[0027]
【The invention's effect】
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.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a shield machine 1. FIG.
FIG. 2 is a view taken along the line II-II in FIG.
3A is an accommodation state diagram and FIG. 3B is a segment support state diagram of the expansion mat 12 constituting the segment shape holding body.
4A is a housing state diagram, and FIG. 4B is a segment supporting state diagram according to a modification of the expansion mat 12 constituting the segment shape holding body.
5A is a housing state diagram and FIG. 5B is a segment supporting state diagram of a hydraulic jack constituting the segment shape holding body.
FIG. 6 is a diagram showing a unitized structure example of a front segment holding body 12 and a rear segment holding body 12 located on a tunnel longitudinal direction line.
FIG. 7 is a diagram showing the arrangement of a friction reducing member including a bearing device 20 with respect to a segment holder.
[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 (2)

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 serves as the outer shell of the shield machine and at the rear side position. In the shape retaining device for the segment,
As the segment holder, an expansion mat that can be moved back and forth or expanded and contracted toward the center of the tunnel by a fluid such as liquid, gas, oil, or the like is disposed on the upper side in the circumferential direction of the skin plate. A segment shape holding device characterized in that a hydraulic jack is arranged on the circumferential lower region side . Wherein the segment abutment segment holder, the shape-retaining device of a segment of claim 1 Symbol placement friction reducing treatment or subjected, or is provided with a wear reduction member for facilitating sliding.

Images