JP2683640B2 - Forearm segment - Google Patents

Description

Description: “Industrial application field” The present invention relates to an arm branch segment used for a tubular wall for lining an excavation hole, which is applied to the lining of a double excavation hole. Is.

[Background Art] In recent years, as a large-section shield method for constructing a large-section tunnel structure such as a railway tunnel, a so-called double-circle special-section shield method has been used.

This method uses a shield excavator with a structure in which two cylindrical shield excavators are connected to each other, and
Two circles are excavated in a cocoon-shaped cross-section where they overlap and a segment is assembled on the inner surface of this excavated hole to form a tubular wall body, and this tubular wall body is formed along the hole. By connecting multiple (primary lining), filling the gap between the rear surface of this primary lining segment, that is, the segment ground, with an injecting material, and then wrapping concrete on the inner surface of the primary lining ( Secondary lining), by which they support the natural ground and form a predetermined inner sky.

As such a conventional tubular body for lining, for example, the one shown in FIG. 7 is known.

This tubular wall for lining is formed along an excavation hole having a cocoon-shaped cross-sectional shape in which the above-mentioned two circles are continuously formed in the horizontal direction and partially overlap each other. Of the above two circles, a main wall portion 1a formed inside the circle on one side orthogonal to the axial direction of the drill hole, a main wall portion 1b formed inside the circle on the other side, and these main It is roughly composed of a branch segment 2 for connecting the upper ends of the walls 1a and 1b to the lower ends thereof, and a middle pillar 3 provided between the upper and lower two branch segments 2, 2. It will be.

The main wall portions 1a, 1b are arcuate plate-shaped steel segments 4
And a key segment 5 that is slightly shorter than the circular arc plate steel segment 4, and these plural circular arc plate steel segments 4 and one key segment 5
Of the two C-shaped segments (one span) formed by connecting both end faces in the longitudinal direction of the drill with bolts and nuts on the surface perpendicular to the axial direction of the drill hole. , C-shaped connecting bodies 6 are arranged so that their openings face each other, and the two connecting bodies 6, 6 arranged in this way are
It is formed by sequentially arranging in the axial direction of the excavation hole and connecting the side surfaces of the adjacent connecting bodies 6 with bolts and nuts.

The branch segment 2 has a rectangular planar shape,
In addition, the side surface is lightly curved in a substantially V shape, and the base portion includes two connecting arm portions 7 and 7 that are connected to the end portions of the connecting bodies 6 and 6 and the curved convex portion that is connected to the center pillar 3. And 8 substantially. The curved convex side of the branch segment 2 is directed toward the inside of the excavation hole to form the connecting bodies 6, 6 described above.
Between the upper end faces of the two connecting bodies 6, 6 facing each other in the longitudinal direction at both end faces in the longitudinal direction thereof, and are connected by bolts and nuts or the like. . Also, similarly, the above-mentioned connecting bodies 6, 6
Similarly, the lower end faces are similarly arranged and connected.

The connecting body 6 forming the main walls 1a and 1b is composed of a plurality of arc plate steel segments 4 and one key segment 5 slightly shorter than the arc plate steel segments 4 as described above. The connecting body 6 is provided such that, depending on the position of the key segment 5, the key segment 5 is provided adjacent to the branch segment 2 arranged on the upper side of the tubular wall body.

The key segment 5 is provided adjacent to the branch portion segment 2 arranged on the lower side of the tubular wall body.

2 types are provided, and by arranging these 2 types of connecting bodies 6 alternately in the axial direction of the excavation hole, the main wall portion 1a,
In 1b, the arcuate plate-shaped steel segments 4 are arranged in a staggered pattern.

In this way, it is taken into consideration that the arcuate plate-shaped steel segments 4 are arranged in a staggered manner on the main wall portions 1a and 1b because the end faces in the longitudinal direction of the arcuate plate-shaped steel segments 4 must be arranged in a staggered manner. The joint surface at, ie
Since the joint surface parallel to the axial direction of the excavation hole exists on one plane, there is a problem in the connection strength of the lining tubular wall body, and the stability of the tubular wall body decreases. Is.

However, in order to arrange the arcuate plate-shaped steel segments 4 in a zigzag manner, as described above, the key segments 5 which are slightly shorter than the arcuate plate-shaped steel segments 4 are required, and there is a problem that the number of kinds of segments increases.

In order to solve the above problem, the two connecting arm portions 7,
7 branching segments of different lengths (hereinafter,
It is a segment of the arm branch. ) Has been proposed as a tubular wall for lining.

FIG. 8 shows a lining tubular wall body using the different arm branch segment. The tubular wall body for lining shown in FIG. 8 differs from that shown in FIG. 7 in that the portion of the key segment 5 arranged adjacent to the branch segment 2 shown in FIG.
In FIG. 8, the point is that, of the two connecting arm portions of the different arm branch portion segment 9, it is integrated with the longer one of the long connecting arm portions 7a. Thus, by using the different-arm branching segment 9 including the long connecting arm portion 7a, the connecting arm portion 7a, the connecting arm portion 7, and the base portion 8, the lining tubular wall body without using the key segment 5 Can be configured, and the above-mentioned problem that the number of types of segments increases can be solved.

"Problems to be Solved by the Invention" By the way, the main girder of the arc plate steel segment 4 is formed by cutting a steel plate called a flat bar whose plane shape is an arc shape in a direction perpendicular to its longitudinal direction. is there. Therefore, this flat bar is used in a large amount, mass-produced, and provided at a relatively low cost. At the time of forming the branch main girder which is a member of the branch segment 2, it was attempted to use the flat bar because it is supplied at a low cost, but the shape of the branch main girder is flat bar. It was impossible to use this flat bar because it was very different from. Therefore, the branch main girder is usually formed by cutting a steel plate. Even when the steel plate is cut to form the branch main girders in this manner, the branch main girders have a relatively small shape, so that the manufacturing cost does not increase.

However, when the branch main girder of the different arm branch segment 9 is formed by cutting it from a steel plate, there is a problem that the manufacturing cost becomes very high because the shape is large.
In addition, since the shape of the branch main girder is significantly different from that of the flat bar, it is impossible to form the branch segment by using the flat bar as it is.

The present invention has been made in view of the above circumstances, and it is possible to reduce the number of types of segments used when constructing a tubular wall body for lining an excavation hole, and to manufacture at low cost. The purpose is to provide partial segments.

[Means for Solving the Problem] In the present invention, an arm having a short length between two arm portions is defined as a different arm branch portion segment in which two arm portions connected to the arc-shaped steel segment have different lengths from each other. The above problem is solved by using a different arm branch segment composed of a common base part and an extension arm part connected to one of the arm parts of the common base part.

[Operation] By constructing the different arm branch segment from the common base and the extension arm, the size of the main girder of the common base obtained by cutting the steel plate is the same as the main girder of the conventional branch segment. Since the size is relatively small, it is also relatively inexpensive, and for the extension arm that constitutes the different arm branch segment together with the common base, use the member obtained by cutting the normally used flat bar for its main girder. Can be manufactured at low cost. Therefore, the manufacturing cost of the different arm branch portion segment does not increase.

"Example" Hereinafter, the different arm branch part segment of this invention is demonstrated in detail.

As described above, the different arm branch portion segment of the present invention is characterized in that the different arm branch portion segment is composed of the common base portion and the extension arm portion.

First, an example of the common base will be described with reference to FIG. Reference numeral 10 in the figure indicates the common base. Common base
The reference numeral 10 is a Y-shaped appearance having two short arms 11 and 11 and a base 12, and is a plate-shaped common base having two Y-shaped planes facing each other. Between the girders 13, 13 and one of the arm bodies 14, 14 of the common base main girders 13, 13 and the end face, that is, the common base joint plate provided on the end face of the one arm part 11.
15, and in the vicinity of the end face of the base portion 12, the central column joint plate 16 provided between the common base portion main girders 13 and 13 perpendicularly to the common base portion main girders 13,
The surface provided between the two end faces of the arms 11 and 11 is the base 12
Is substantially configured from a common base skin plate 17 having a rectangular shape in a plane and a side surface having an arc shape, which is provided on a surface opposite to the end surface.

Next, the extension arm portion joined to the common base portion 10 will be described with reference to FIG. Reference numeral 4 in the figure indicates an arcuate plate steel segment. The circular arc plate-shaped steel segment 4 is a circle formed by attaching the joint plates 19 and 19 to both ends of the pair of arc-shaped main girders 18 and 18, respectively, and forming the main girders 18 and 18 and the joint plates 19 and 19. The skin plate 20 is welded to the outer periphery of the arcuate rectangular body, and the skin plate is further welded.
A rib 21 is welded to the inner peripheral surface of 20. The main girder 18 is obtained by cutting a steel plate, which is usually called a flat bar, having an arcuate planar shape into a predetermined length. From the viewpoint of manufacturing cost, it is preferable that the main girder of the extension arm portion used in the present invention (hereinafter referred to as the extension arm portion main girder) is formed using this flat bar,
It is preferable that the flat bar, like the main girder 18, is formed by cutting the flat bar at a predetermined length perpendicular to its longitudinal direction.
Here, in order to assemble the arcuate plate-shaped steel segments 4 in a zigzag manner in the tubular wall body, it is necessary to make the length different from the extension arm main girder 18.

Regarding an example of the arm branch portion segment of the present invention,
This will be described with reference to the drawings. The different arm branch portion segment includes the common base portion 10 having a substantially Y-shaped appearance and the extended arm portion 22 having an arc plate shape.
It is composed of This extension arm 22
A pair of arcuate extension arm main girders 23, 23, a skin plate 20 joined to the outer peripheral surfaces of the extension arm main girders 23, 23, and one end surface of the extension arm main girders 23, 23 The joint plate 19 is configured to be substantially the same, and the joint plates 19 of the extension arm portions 23, 23 are joined to the common base portion 10 at the non-joined end faces. The extension arm main girder 23 is formed by cutting the flat bar perpendicularly to its longitudinal direction, and one end face in the longitudinal direction thereof is formed on the end face of the arm body 14 of the common base main girder 13. The side surface on the inner peripheral side of the extended arm main girder 23 is welded to the base 12 side of the common base 10 by a vertical rib 24.

The end face of the extension arm main girder 23 and the arm of the common base main girder 13
A method for joining the end face 14 will be described with reference to FIGS. 4 to 6.

FIG. 4 shows an example of welding using the vertical ribs 24. The vertical rib 24 is a rectangular plate-shaped steel material, and two side surfaces of the vertical rib 24 that are parallel to each other are two end surfaces of the arm bodies 14 and 14 and the extension arm main girders 23 and 23 in the longitudinal direction. Junction 25,
It is arranged so as to cover the portions of 25 facing each other. After being arranged in this way, this vertical rib 24,
The extension arm main girders 23, 23 and the arm bodies 14, 14 are welded to the sides on both sides of each of the two side surfaces.

FIG. 5 shows the end faces of the arms 14 and 14 and the extended arm main girders 23 and 23.
It shows an example in which the end faces of and are welded in a state of being abutted against each other. Grooves having a Y-shaped cross section are previously formed by cutting or the like at the portions of the two joint portions 25, 25 facing each other. The arm bodies 14 and 14 and the extended arm main girders 23 and 23 are
The V-shaped grooves are welded to each other to be joined.

FIG. 6 shows an example in which a rectangular plate-shaped contact plate 26 is used for joining by welding. The contact plates 26, 26 have joints 25, 25.
In the portions facing each other, the two parallel sides of the contact plate 26 are parallel to the joint 25, and the surfaces are arranged so as to cover the joint 25. , Main arm extension girder 23, respectively
And is welded to the arm 14.

The method of joining the extended arm main girder 23 and the arm 14 of the common base 10 has been described above, but the present invention is not limited to the above joining method.

"Effects of the Invention" In the present invention, the different arm branching segment in which the lengths of the two arm portions connected to the arc-shaped steel segment are different from each other, the length of the two arm portions is set to the length of the short arm portion. Since it is a different-arm branching segment composed of a common base and an extension arm connected to one of the arms of the common base, the size of the main girder of the common base obtained by cutting the steel plate is Since the size is the same as that of the main girder of the conventional branch segment, it is relatively inexpensive. Also, the extended arm portion that constitutes the different arm branch portion segment together with the common base portion can be manufactured at low cost by using a member obtained by cutting a commonly used flat bar for the main girder. Therefore, the present invention has an effect that it is possible to inexpensively manufacture a different arm branch portion segment in which a circular arc plate steel segment can be assembled in a zigzag manner without using a key segment in a tubular wall body.

[Brief description of the drawings]

1 is a schematic perspective view showing a common base used in the present invention, FIG. 2 is a schematic perspective view showing an arcuate plate-shaped steel segment for explaining an extension arm used in the present invention, and FIG. 3 is a book. The schematic perspective view which carried out the partial cross section which shows an example of invention,
4 to 6 are schematic perspective views showing an example of joining the common base portion and the extension arm portion, and FIGS. 7 and 8 are schematic perspective views showing a conventional tubular wall for lining. 1a, 1b …… Main wall, 2 …… Branch segment, 4 …… Arc plate steel segment, 10 …… Common base, 11 …… Arm, 22 …… Extended arm.

Claims (1)

(57) [Claims] 1. A C-shaped cross-section composed of a plurality of arc-plate-shaped steel segments assembled along a peripheral wall of a drill hole formed such that two drill holes each having a circular cross section overlap each other. The main wall portion and the inverted C-shaped main wall portion in cross section,
In the different-arm branching segment that is connected at the upper end and the lower end and has different lengths of the two arms connected to the arc-shaped steel segment, the different arm branching segment is divided into two arm parts. An arm branch segment having a common base having a length equal to the length of a short arm and an extension arm coupled to one of the arms of the common base.