JPH04119899U - arcuate rectangular segment - Google Patents

Abstract

(57) [Summary] [Purpose] In shield tunnels, by taking advantage of the occupied area and width of the rectangular cross section, it is possible to reduce the thickness mechanically by taking advantage of the occupied area and width of the rectangular cross section. To provide a simple arcuate rectangular segment that is sufficiently durable. [Structure] In an arcuate rectangular segment constituting a substantially rectangular shield tunnel with a cross section consisting of left and right side sections, a top section, and a bottom section, at least an even arcuate rectangular section has a small same radius of curvature r. a segment piece forming a part;
A segment piece having a radius of curvature R _S corresponding to the large span and forming the top and bottom parts of the arcuate rectangular cross section, and a side of the arcuate rectangular cross section having a radius of curvature R _L corresponding to the small span. It has segment pieces forming a printing section, and the radius of curvature R _L corresponding to the small span is larger than the radius of curvature R _S corresponding to the large span, and each segment piece 1a to 1g is the same. It forms an arcuate segment of thickness T.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to arcuate rectangular segments used in constructing underground tunnels. do.

0002

[Conventional technology]

The conventionally used shield tunnel segments have a cross-sectional shape of The most common shape is circular, but there are also rare horseshoe, rectangular, or compound circular shapes, depending on the design conditions, Select as appropriate depending on ground conditions, environmental conditions, etc., and select an adaptable cross-sectional shape for construction. I've done it.

0003 Recently, rectangular cross-section tunnels have been developed and constructed for the purpose of effectively utilizing underground space. construction is being carried out. In construction of this rectangular cross-section tunnel, as shown in Figure 3, segment is used. In the figure, A is the corner segment piece, B is the side Segment piece of the printing section, C is the segment piece of the top printing section, D is the segment piece of the bottom printing section. It is called a piece. In particular, the inside edge E of the corner segment piece A has a haunch. Also called, as one of the means to resist stress concentration, the intersection between the horizontal and vertical directions A reinforcing slope is provided on the inside.

0004 In each of these segment pieces, from the longitudinal side of corner segment piece A Arranged at the four corners so that the short sides face in the same direction, side plate part B and top plate part C or The bottom plate parts D were arranged and assembled. Here, the top plate part C and the bottom plate part D are almost the same segment pieces, and are actually constructed using three types, A, B, and C. It was customary to build Then, the length of the corner segment piece A to be placed next Assemble so that the short side faces the opposite direction, dispersing the direction of concentration of force. It was standing.

[0005]

[Problem that the idea aims to solve] However, since each segment piece above has a linear configuration, the earth pressure A large bending moment is generated in the member due to external forces such as water pressure, and this large bending moment Each segment piece must be thick enough to withstand the stress and axial forces. Of course, if each segment piece is made of concrete, a large number of reinforcing bars etc. will be required. This increases material costs and transportation weight, and reduces safety, assembly efficiency, and economy. There was a problem with sexuality.

[0006] This invention was created to solve such problems, and its purpose is The reason for this is that in shield tunnels, the rectangular cross section has the advantage of occupying area and occupying width. Taking advantage of the The object is to provide a simple arcuate rectangular segment that is durable enough.

[0007]

[Means to solve the problem]

In order to achieve the above object, the present invention provides an arcuate rectangular segment that constructs a substantially rectangular shield tunnel with a cross section consisting of left and right side sections, a top section, and a bottom section, each having a small same radius of curvature r. A segment piece having a radius of curvature R _S corresponding to the large span and forming at least a joint part of an arcuate rectangular cross section, a segment piece forming a top part and a bottom part of an arcuate rectangular cross section, and a small segment piece. It is composed of segment pieces that have a radius of curvature R _L corresponding to the span and form the left and right side sections of an arcuate rectangular cross section, and the radius of curvature R _L corresponding to the small span corresponds to the large span. The radius of curvature R _S is larger than the radius of curvature R S , and each of these segment pieces is formed into an arcuate shape with the same thickness.

[0008] Further, in the present invention, in the above-mentioned arcuate rectangular segment, each adjacent segment A feature that the extension line of the connecting surface between pieces passes through the center of curvature of each segment piece. shall be.

[0009]

[Effect]

With the above configuration, the arcuate rectangular segment of the present invention has an arcuate shape due to its outer shape. The arch structure increases mechanical strength and reduces cross-sectional dimensions. In addition, most of the segment pieces forming the bow shape have the same radius of curvature. Because of the thickness, the shape can be simplified and the construction between each segment piece can be simplified. The external force used can be reliably dispersed.

0010

【Example】

Hereinafter, a preferred embodiment of the present invention will be described based on FIGS. 1 and 2. FIG. 1 is a cross-sectional view of the segment, and FIG. 2 is a plan view thereof. Segment 1 includes segment pieces 1b and 1a formed with a radius of curvature R _S in a bottom plate portion corresponding to a large span (here, span refers to a designed distance between supports supporting a load); It is formed by a segment piece 1c formed by an arcuate joint portion having a radius of curvature r that is smaller than the radius of curvature R _S and a radius of curvature R _L .

[0011] In addition, in the top plate part, a segment piece 1b formed with a radius of curvature R _S , a circular arc-shaped joint part with a radius of curvature r smaller than the radius of curvature R _L , and a segment piece formed with a radius of curvature R _S 1c, a wedge-shaped segment piece 1g whose segment width is linearly formed from the shield tunnel face side toward the tunnel entrance with a radius of curvature R _S , and a wedge-shaped segment piece 1g with a radius of curvature R _S from the shield tunnel face side toward the tunnel entrance. , segment pieces 1f and 1e each having a linearly large segment width.

[0012]Furthermore, in the portion forming the side plate portion, in the left and right side plate portions corresponding to the small spans, segment pieces 1c formed by a radius of curvature R _L , a small radius of curvature r, and an opposite curvature Rs, Consists of 1d. These segment pieces 1a to 1g have the same thickness T, and R _S <R _L. Of course, the wedge-shaped segment may be a so-called tapered segment inserted from the inside of the segment toward the outside.

In other words, this segment has two large curvature radii, R _L and R _S (R _L > R _S ), and the left and right side sections, the top section, and the bottom section have an arcuate shape with the same thickness T. The even portions are formed to have the same radius of curvature r smaller than R _L and R _S . That is, the segment pieces 1c and 1d of the right side plate are formed in an arch shape with a radius of curvature R _L and a thickness T centered on a point M, and the top plate and bottom plate have curvatures centered on points N and N', respectively. It is formed into a bow shape with a radius R _S and a thickness T.

[0014] In addition, the segment pieces 1c and 1d constituting the four joints are located at points M, M' or or has a radius of curvature RL centered at points N, N', has a thickness T, and has central angles θM, θM ′ or θN, θN′, and the thickness T with a small radius of curvature r centered on point O. It has a circular arc shape with a central angle θO. This small radius of curvature r The center O is the intersection of the central angles θM, θM', θN, and θN' of the two large radii of curvature. In this case, θM=θM' and θN=θN'. And each of these sections Extension lines of adjacent connecting surfaces of component pieces 1a, 1b, 1c, 1d, 1e, 1f all pass through the center points M, M', N, and N' of the arch shape.

[0015] During assembly, one segment piece 1a, three segment pieces 1b, two segment pieces 1c, two segment pieces 1d, and one each of segment pieces 1e, 1f, and 1g, for a total of 11 Together, they form a set of arcuate segments. In addition, if the shield tunnel to be constructed underground requires a vertically long rectangular cross section due to the purpose of use, the radius of curvature of the side slab of the approximately rectangular segment is R _S , and the curvature of the top and bottom slabs is R S . The radius may be R _L , or they may be formed with different radii of curvature.

[0016] When constructing a horizontally elongated shield tunnel with a substantially rectangular cross section underground, the earth pressure and water pressure that normally act on this segment cross section are: water pressure is added to this. However, in the side slab section, the earth pressure is dominated by the pressure due to the overburden multiplied by the lateral pressure coefficient λ (λ≒0.35 to 0.75), which is added to the water pressure. , the external force in the lateral direction is smaller than the external force in the downward direction. Moreover, the designed span is large in the lateral direction and small in the vertical direction, so in such a situation, the radius of curvature R _S of the segments of the top and bottom slabs is smaller than the radius of curvature R _L of the side slabs. By making it small, and due to the characteristics of the arch structure, the segments can effectively resist external forces.

[0017] In other words, internal stress generated in the segment due to earth pressure or water pressure, such as bending moment, Compared to conventional linear rectangular segments, bending moments are particularly low in terms of torque and axial force. By being able to reduce the segment thickness T, it is possible to make the segment thickness T thinner than before. This makes it possible to improve work efficiency in transportation, assembly, etc.

In addition, since the entire segment has an arch shape composed of arcs with different radii of curvature R _L , R _S and r, the mechanical characteristics of the arch structure can be fully utilized, and the segment thickness T can be made thinner. This makes it possible to reduce the amount of reinforcing bars, which is economically advantageous.

[0019] Furthermore, although the overall cross-sectional shape of the above-mentioned segments is rectangular, each segment Since the segment is arc-shaped or circular arc-shaped with curvature, each adjacent segment Form the extension line of the connecting surface between pieces to pass through the center of curvature of each segment piece. By doing so, even if earth pressure or water pressure acts from the outside of the segment, the adjacent yag The ment pieces do not collapse inward because they interlock with each other due to arching action. It is also extremely safe.

[0020]

[Effect of the idea]

As explained above, in the present invention, rectangular segments that construct a substantially rectangular shield tunnel whose cross section is composed of left and right side sections, a top section, and a bottom section have a small and the same radius of curvature r, and at least an arch. A segment piece forming a joint part with a rectangular cross section, a segment piece having a radius of curvature Rs corresponding to a large span and forming a top plate part and a bottom plate part of an arcuate rectangular cross section, and a curvature corresponding to a small span. The segment piece has a radius R _L and forms a side section having an arcuate rectangular cross section, and the radius of curvature R _L corresponding to the small span is larger than the radius of curvature R _S corresponding to the large span. Since each of the segment pieces 1a to 1g is formed into an arcuate segment with the same thickness T, the extension line of the connecting surface between adjacent segment pieces has a center of curvature of each segment piece. By passing through the rectangular area, it is possible to take advantage of the occupied area and width of the rectangular area, to make it thinner in consideration of workability in manufacturing, transportation, assembly, etc., and it can be used as a simple segment that is mechanically safe. can.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an arcuate rectangular segment according to the present invention.

FIG. 2 is a plan view of FIG. 1;

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

[Explanation of symbols]

1 Segments 1a, 1b, 1c, 1d, 1e, 1f, 1g Segment pieces R _L , R _S Large radius of curvature r Small radius of curvature T Thickness M, M', N, N' Center

──────────────────────────────────────────────── ─── Continuation of front page (72) Creator Ryo Terashima Daihoken, 1-24-4 Shinkawa, Chuo-ku, Tokyo Inside the company (72) Creator Yukihiro Kitamura Daihoken, 1-24-4 Shinkawa, Chuo-ku, Tokyo Inside the company

Claims (2)

[Scope of utility model registration request] Claim 1: In an arcuate rectangular segment constituting a substantially rectangular shield tunnel with a cross section consisting of left and right side sections, a top section, and a bottom section, at least an arcuate rectangular section having a small same radius of curvature r. A segment piece forming a joint part, a segment piece having a radius of curvature R _S corresponding to the large span, and forming a top plate part and a bottom plate part of an arcuate rectangular cross section, and a radius of curvature R corresponding to the small span. The segment piece has a radius of curvature R _L corresponding to the small span and is larger than the radius of curvature R _S corresponding to _the large span. An arcuate rectangular segment characterized in that each of the segment pieces 1a to 1g is formed into an arcuate shape with the same thickness T. 2. In the arcuate rectangular segment according to claim 1, the extension line of the connecting surface between adjacent segment pieces is located at the center of curvature M, M', N, N' of each segment piece.
An arcuate rectangular segment characterized by passing through.