JPH089276Y2 - Rectangular segment - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rectangular segment used when constructing a tunnel in the ground.

[0002]

2. Description of the Related Art The most commonly used shield tunnel segment has a circular cross section,
There are rare cases such as horseshoe, rectangle or compound circle, which have been selected appropriately according to design conditions, ground conditions, environmental conditions, etc., and have been selected with a suitable cross-sectional shape.

Recently, a rectangular tunnel has been developed and constructed for the purpose of effectively utilizing the underground space.
In the construction of this rectangular cross-section tunnel, segments as shown in FIG. 3 are used. In the figure, A is a corner segment piece, B is a side segment segment piece,
C is called a segment piece of the top plate portion, and D is called a segment piece of the bottom plate portion. Especially corner segment piece A
The inner side E is also called a haunch, and as one means for resisting stress concentration, a reinforcing inclined portion is provided inside the intersection of the horizontal direction and the vertical direction.

In each of these segment pieces, the corner segment pieces A are arranged in four corners from the long side to the short side in the same direction, and the side plate portion B and the top plate portion C or the bottom plate portion D are provided. They were all arranged and assembled.
Here, it is customary that the top plate portion C and the bottom plate portion D are substantially the same segment piece, and are substantially constructed by using three kinds of A, B, and C. Then, the corner segment pieces A to be arranged next are assembled so that the direction from the long side to the short side is directed in the opposite direction and the force concentration directions are dispersed.

[0005]

[Problems to be Solved by the Invention] However, since each of the above segment pieces has a linear configuration, earth pressure,
A large bending moment is generated in the member by external force such as water pressure, and in order to counter this large bending moment and axial force, the thickness of each segment piece must be sufficient, and when each segment piece is made of concrete, However, since many rebars are required, the material cost, the transportation weight, etc. are increased, and there are problems in safety, assembling efficiency and economy.

The present invention has been made to solve the above problems, and an object of the present invention is to manufacture a shield tunnel by taking advantage of the occupied area and the occupied width of a rectangular section. It is an object of the present invention to provide a simple rectangular segment that can be mechanically sufficiently filled even if the thickness is reduced in consideration of workability in transportation, assembly and the like.

[0007]

In order to achieve the above-mentioned object, the present invention provides a rectangular segment for constructing a shield tunnel having a substantially rectangular cross section, which is composed of a corner portion, a side plate portion, a top plate portion and a bottom plate portion. , A segment piece having a small same radius of curvature and forming at least a corner of a rectangular cross section, and a segment piece having a large radius of curvature and forming a side plate portion, a top plate portion, and a bottom plate portion of a rectangular cross section. , Each of these segment pieces is formed in an arc shape having the same thickness.

Further, the present invention is characterized in that, in the above-mentioned rectangular segment, an extension line of a connecting surface between adjacent segment pieces passes through a center of curvature of each segment piece.

[0009]

With the above structure, the rectangular segment of the present invention is
Since the outer shape is an arch structure with an arcuate shape, it is possible to increase the mechanical strength and reduce the cross-sectional quantities, and many segment pieces that are bow-shaped have the same radius of curvature and the same thickness. Therefore, the shape can be simplified, and the external force acting between the segment pieces can be surely dispersed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to FIGS. Figure 1 is a cross-sectional view of a segment,
FIG. 2 is a top view thereof. The segment 1 is a segment piece 1b formed in an arc shape having a large radius of curvature R,
A segment piece 1a having a large radius of curvature R and a small corner having the same radius of curvature r, and a large radius of curvature R are provided, and the segment width is linear from the shield tunnel face side to the wellhead side. It is composed of a wedge-shaped segment piece 1d with one taper that is small in size, and a segment piece 1c that has a large radius of curvature R and that has a linearly large segment width from the face side of the shield tunnel toward the wellhead side. Has been done. Then, each of these segment pieces 1a to 1d is formed in a bow shape having the same thickness T. The wedge-shaped segment piece 1d is
The taper segment may not necessarily be a single taper but may be a double taper, or may be a so-called taper segment that is inserted from the inside to the outside of the segment.

In other words, in this segment 1, the side plate portion, the top plate portion and the bottom plate portion are formed in an arc shape having a large radius of curvature R and the same thickness T, and the corner portion (1a) has a small same curvature. It is formed with a radius r. That is, the segment piece 1b of the right side plate portion is formed in an arc shape with a radius of curvature R and a thickness T around the point M, and the top plate portion and the bottom plate portion have a radius of curvature R around the points N and N ', respectively. Thickness T
Is shaped like a bow.

The segment piece 1a constituting the four corners (1a) has a large radius of curvature R centered on the point M, M'or N, N ', a thickness T, and a center. It has an arcuate shape with angles θ _M , θ _M ′ or θ _N , θ _N ′, a small radius of curvature r centered on the point O, a thickness T, and an arc shape with a central angle θ _O. . This small radius of curvature r
Is the center O of the large radius of curvature θ _M , θ _M ′, θ
Intersection point with _N and θ _N ′, in which case θ _N = θ _N ′, θ
_M = θ _M ′. The extension lines of the adjacent connecting surfaces of these segment pieces 1a, 1b, 1c, 1d all pass through the arch-shaped center points M, M ', N, N'.

Upon assembly, a total of eight segment pieces 1a, two segment pieces 1b, and one segment piece 1c and one segment piece 1d are combined to form one set of segments. . In addition,
The side plate portion, the top plate portion, and the bottom plate portion of the substantially rectangular segment may be formed with the same large radius of curvature R, or may be formed with different radiuses of curvature.

As described above, each of the segments has a large radius of curvature R and a small radius of curvature r, and is formed into an arc-shaped segment having the same thickness T, so that it acts in the soil. External forces due to soil and water pressure can be countered by the mechanical characteristics of the arch structure.

That is, regarding the internal stress generated in the segment due to soil or water pressure, such as bending moment or axial force,
Since the bending moment can be made smaller than that of the conventional straight rectangular segment, the thickness T of the segment can be made thinner than that of the conventional one, and the workability of transportation, assembly and the like is improved.

Further, the radius of curvature R for the entire segment is different.
Since it has a bow shape composed of the arcs of r and r, the mechanical characteristics of the arch structure can be fully utilized, the segment thickness T can be made thinner, or the amount of rebar can be reduced, which is economical. Is advantageous.

Further, although the above-mentioned segment has a rectangular cross-sectional shape as a whole, each segment has an arc shape or an arc shape having a curvature, and the extension line of the connecting surface between adjacent segment pieces is By forming to pass through the center of curvature of each segment piece, even if earth pressure or water pressure acts from the outside of the segment, adjacent segment pieces do not collapse inward because they mesh with each other due to the arch effect, The safety is also extremely high.

[0018]

As described above, according to the present invention, in a rectangular segment for constructing a substantially rectangular shield tunnel having a cross section of a corner portion, a side plate portion, a top plate portion, and a bottom plate portion, a corner portion and a side plate are formed. Section, top plate, and bottom plate segment pieces have two types of radii of curvature, that is, each corner has a smaller radius of curvature r.
And the side plate portion, the top plate portion, and the bottom plate portion have a large radius of curvature R and have an arc shape having the same thickness T and have a generally rectangular cross section. , The extension line of the connecting surface between adjacent segment pieces passes through the center of curvature of each segment piece, making the most of the occupied area and width of the rectangular area, taking into consideration workability such as production, transportation, and assembly. There is an advantage that it can be made thin and can be used as a simple segment that is mechanically safe.

[Brief description of drawings]

FIG. 1 is a sectional view of a segment according to the present invention.

FIG. 2 is a top view of FIG.

FIG. 3 is a sectional view of a conventional example.

[Explanation of symbols]

 1 segment 1a, 1b, 1c, 1d segment piece R large radius of curvature r small radius of curvature T thickness M, M ', N, N'center

Front Page Continuation (72) Creator Yukihiro Kitamura 1-24-4 Shinkawa, Chuo-ku, Tokyo Inside Daitoyo Kensetsu Co., Ltd. (56) Bibliography 62-41120 (JP, Y2)

Claims (2)

[Scope of utility model registration request] 1. In a rectangular segment for constructing a substantially rectangular shield tunnel having a cross section of a corner portion, a side plate portion, a top plate portion, and a bottom plate portion, at least a corner portion of a rectangular cross section having a smaller same radius of curvature. And segment pieces that form a side plate portion, a top plate portion, and a bottom plate portion having a large radius of curvature and a rectangular cross section, and each of these segment pieces is formed in an arc shape with the same thickness. A rectangular segment characterized by: 2. The rectangular segment according to claim 1, wherein an extension line of a connecting surface between adjacent segment pieces passes through a center of curvature of each segment piece.