JPH0467000B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of a tunnel lining segment having a rectangular plane and curved in an arc shape.

(Prior technology) Conventionally, in shield tunneling, after excavating the ground with a shield machine, segments in the shape of a plurality of divided tunnel outer circumferences are assembled in the rear end tail of the shield machine, and the segments are used as a reaction force to drive the shield machine. It is being dug.

A plurality of these segments are assembled to form an annular shape, and a segment called a key segment is specifically used for assembly within a narrow tail portion.

This key segment has an open V-shape in which the inner circumferential surface is wider than the outer circumferential surface at the ring joint surface.

(Means for solving the problem) For this reason, when earth pressure acts on segments assembled in a ring shape, tensile force is generated only on the inner peripheral surface of the key segment, which is supported by bolts. This was the weak point of the tunnel structure.

Spiral segments were developed early on to solve this problem, but the propulsion jack of the shield machine had to use the slanted surface of the segment as a reaction force as a reaction force, creating uneven pressure on the jack surface. At the same time, the outer circumferential earth pressure must be countered only with the connecting bolts in the ring direction, and the inner diameter of the ring gradually decreases due to the bolt hole allowance, making it difficult to assemble the segments one after another. A problem arose. Furthermore, in order to make the long side end faces of the segments connected in the longitudinal direction of the tunnel come into close contact with each other, the end faces must be formed into complex spirally twisted surfaces, which is extremely difficult to process. Ta.

An object of the present invention is to provide a tunnel lining segment that can solve these problems.

(Means for Solving the Problem) In order to achieve the above object, the segment of the present invention has a rectangular plane with a long side length l and a short side length b,
A segment whose long side is curved in an arc shape,
Length 1/2 x l, depth 1/2 from the end on one side of the long side
A protruding piece protruding by n×b is provided, and both short side end faces and the short side end face of the protruding piece are oriented toward the center of curvature of the arc-shaped segment, and the long side Both end surfaces and the long side end surface of the projecting piece are perpendicular to the outer peripheral surface of the segment, and n+1/2 segments (n is a positive integer of 4 or more) form one circular ring. It consists of

(Function) When lining a tunnel wall excavated by a shield machine using the segments formed as described above, one ring is formed by n and 1/2 segments, and the second ring is the same as the first arrangement. do. Therefore,
The joints between the rings are in a connected state in which they are sequentially shifted by 1/2 segment from each other, so that weak points in the segment joints can be strongly reinforced between the rings. That is,
Since the entire circumference is made up of n+1/2 segments, the junction of the segments in the ring direction opposes the center of the segment of the adjacent ring, and the rings reinforce each other to improve the overall shape. It is capable of forming a strong lining.

Furthermore, add a length of 1/2 from the end to one side of the long side.
By means of the protruding pieces protruding by ×l and depth 1/n×b, the segments are sequentially engaged and connected to form a ring having a constant diameter.

In addition, since the joint surfaces between the segments in the circumferential direction of the tunnel are oriented toward the center of curvature of the segments, a stable stress state is created against earth pressure, and the joint surfaces in the longitudinal direction, that is, the long sides of the segments, are in a stable stress state against earth pressure. The side end face is formed to be perpendicular to the outer peripheral surface of the segment, and is continuous in the circumferential direction of the tunnel and faces perpendicularly to the axis of the shield jack, allowing the shield machine to be propelled in a fixed direction. Not only is this possible, but the shape is simple and suitable for mass production.

(Example) An example of the present invention will be described based on the drawings. Figures 1 to 3 show segments for lining tunnel walls excavated by the shield method, and this segment 1 is It has a rectangular plane with a length l and a short side length b, and is curved in an arc shape in the long side direction, and one side CG on the long side of the rectangle of b x l
A rectangular projecting piece 2 of size c×l' is provided protrudingly on the side, and each corner is formed at a right angle.

This segment has a thickness d, a circular arc shape with a radius r around the center O, and circumferential joint surfaces AGF, DE, BC.
is formed toward the center O of the circle, that is, in the normal direction to the arcuate outer peripheral surface.

Further, the longitudinal joint surfaces AB, EF, and CD are formed to be perpendicular to the circumferential joint surface and also perpendicular to the segment outer circumferential surface.

The length relationship of the segments in the figure is l'=1/2×l..., and the tunnel circumference (tunnel with radius r) L
is, L=2πr=nl+l'=nl+1/2×l=(n+1/2)l...
(Here, n is the number of divisions and is an integer of 4 or more).

In other words, (n+1/2) of these segments form one ring.

If n=6, one ring will be 6.5 according to the above formula, which will be 6 segments and 1/2 segment.

Further, the second ring, that is, the (2n+1)th ring, is assembled at the same position, and the widths a, b, and c of the segments in FIG. 1 have the following relationship: a+b/2n+1=c...

From this relationship, the widths a, b, c of this segment
Since the relationship for is a=b+c, the formula becomes b=n×c, c=1/n×b...

Here, if n=6, c=1/6×b.

When these are shown in a developed view, they are shown as in FIG.

Furthermore, the side DE may be formed with an inclination 3 as shown in the figure D ₁ and E, and the side AA ₁ may also be formed with an inclination 4 at the same angle as A ₁ A ₂ .

Thereby, when assembling this segment,
The rectangular projecting piece 2 can easily fit into the recess of the already assembled ring.

Segment connections between rings and between rings in the circumferential direction are performed using bolts, pins, etc.

(Effects of the Invention) As described above, according to the present invention, the segment has a rectangular plane with a long side length l and a short side length b, and the long side is curved in an arc shape. A protruding piece protruding from the end by a length of 1/2 x l and a depth of 1/n x b is provided, and both short side end faces and the short side end face of the protruding piece are curved into an arc shape. It is oriented toward the center of curvature of the segment, and both long side end faces and the long side end face of the projecting piece are perpendicular to the outer peripheral surface of the segment, and the segment n+1/2
(n is a positive integer of 4 or more) to form one circular ring, so the joints of the segments in the ring direction face the center of the segments of adjacent rings, and the rings are connected to each other. They can reinforce each other to form a strong lining as a whole.

Furthermore, add a length of 1/2 from the end to one side of the long side.
The protruding pieces protruding by ×l and depth 1/n×b cause the segments to be connected in a sequentially engaged state, thereby preventing the ring shape from contracting due to the outer circumferential earth pressure.

Furthermore, since the joint surfaces between the circumferential segments are oriented toward the center of curvature of the segments, a stable stress state is created against earth pressure, and the ring surface is always perpendicular to the tunnel direction, making it possible to shield Since the jack's spreader is always perpendicular to the jack's axis and is not subjected to biased pressure, the jack does not malfunction and the shield can be propelled in a constant direction.

In addition, the end face on the long side is a flat face facing the circumferential direction of the tunnel, and the end face on the short side is formed as a flat face facing the length direction of the tunnel.
Unlike conventional segments that are assembled in a helical direction, the joining end faces are twisted surfaces, which is not a complicated shape, but an extremely simple shape that is suitable for mass production.

Furthermore, despite the simple shape of the segments, there is no need to propel the shield machine every time one ring is assembled as in the past, and they can be assembled one after the other, and can be assembled even during shield excavation. This allows the construction period to be shortened.

In addition, when assembling segments with a robot, it takes a long time when using conventional erectors and humans, but with this segment, it can be assembled during excavation, so the assembly time can be lengthened and the robot can be used effectively.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a plan view thereof, FIG. 2 is a side view, FIG. 3 is a perspective view, and FIG. 4 is a developed view when the segment of the present invention is implemented. It is. 1... Segment, 2... Rectangular projecting piece.

Claims (1)

[Claims] 1 A segment having a rectangular plane with a long side length l and a short side length b, with the long side curved into an arc, and one side of the long side has a length of 1/2 x l and a depth of 1 from the end. A protruding piece protruding by /n×b is provided, and both end faces on the short side and the end face on the short side of the protruding piece are oriented toward the center of curvature of the segment curved in an arc shape, and the long side Both side end surfaces and the long side end surface of the protruding piece are perpendicular to the outer peripheral surface of the segment, and n+1/2 segments (n is a positive integer of 4 or more) form one circular ring. A tunnel lining segment constructed as follows.