JPH0321800A - Different arm branch segment - Google Patents

Abstract

PURPOSE:To reduce the cost by forming a different arm branch segment used for the central branch of the covering work of an excavated hole of a cocoon form section with a common base and an extension arm, and utilizing conventional members for the both parts. CONSTITUTION:A common base 10 of Y-shape in appearance is formed of a common base main beam 13, a common base joint plate 15, a middle pollar joint plate 16, and a common base skin plate 17. Then, an extension arm 22 is formed of a circular arc form extension arm main beam 23, a skin plate 20, and a joint plate 19. After that, the base 10 and the arm 22 are incorporated by welding by using a longitudinal rib 24, and a different arm branch segment 9 is formed. It is used at the central branch for a covering work of a cocoon form section, and segments 4 are lined up zigzag without using a key segment. As a result, the base 10 and the arm 22 can be made by using the conventinal branch segment and the members for the segments 4 as they are, and they can be manufactured at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a different arm branch segment used in a cylindrical wall body for lining a double drilled hole. It is something.

"Prior Art" In recent years, a method called a double-circular special section shield construction method has been used as a large-section seven-fold construction method for constructing large-section tunnel structures such as railway tunnels.

This construction method uses a shield excavator, which has a structure in which two cylindrical shield excavators are connected, to excavate the ground or ground into a cocoon-shaped cross-sectional shape in which two circles partially overlap. Segments are assembled on the inner surface of the excavated hole to form a cylindrical wall, and a plurality of these cylindrical walls are connected along the hole (primary lining), and the back surface of the segment of this primary lining, i.e. After filling the space between the segment and the ground with an injection material to fill the void, concrete is rolled on the inner surface of the primary lining (secondary lining), which supports the ground and fills the specified inner space. It is about composing.

Examples of such conventional lining cylindrical bodies include:
The one shown in FIG. 7 is known.

This lining cylindrical wall body has a cocoon-shaped I &
It is formed along an excavated hole having a cross-sectional shape, and of the two circles mentioned above, the main wall part 1a is formed inside the circle on one side perpendicular to the axial direction of the excavated hole, and the main wall part 1a is formed on the inside of the circle on the other side. Main wall portion 1b formed inside the circle, and these main wall portions 1a, 1b
It is roughly composed of a branch segment 2 that connects the upper end of each of the upper ends and the lower end of the 2, and a middle note 3 that is provided between the upper and lower two branch segments 2, 2. It is.

The main walls 1a and 1b are composed of a circular arc plate steel segment 4 and a key segment 5 that is slightly shorter than the arc plate steel segment 4. These arc plate steel segments 4 and one key Two C-shaped segment-width (1 span) connecting bodies 6 formed by connecting both ends of the segments 5 in the longitudinal direction with bolts and nuts are connected in a plane perpendicular to the axial direction of the excavated hole. The openings of the C-shaped connecting bodies 6 are arranged so as to face each other, and the two connecting bodies 6, 6 arranged in this way are
are arranged in sequence in the axial direction of the excavated hole, and the side surfaces of adjacent connecting bodies 6 are connected with bolts and nants, respectively.

The branch segment 2 has a rectangular planar shape and a slightly curved side surface in a substantially dogleg shape, and has two connecting arms 7 that connect with the ends of the connecting bodies 6, 6; 7, and a base portion 8 consisting of the above-mentioned curved convex portion connected to the central pillar 3.

The curved convex side of the branch segment 2 is disposed between the upper end surfaces of the connecting bodies 6, 6 toward the inside of the excavation hole, and the openings are formed on both end surfaces in the elongated direction. The upper end surfaces of the two opposing connecting bodies 6, 6 are connected by bolts, nants, etc. Further, the connecting bodies 6, 6 are similarly arranged and connected between the lower end surfaces of the connecting bodies 6, 6.

As described above, the connecting body 6 forming the main walls 1a and 1b is composed of a plurality of arcuate plate-shaped steel segments 4 and one key segment 5 that is slightly shorter than the arcuate plate-shaped steel segments 4. However, in the above-mentioned connecting body 6, the position of the key segment 5 is as follows: (1) The key segment 5 is provided adjacent to the branch segment 2 disposed on the upper side of the cylindrical wall.

(2) The key segment 5 is provided adjacent to the branch segment 2 located below the cylindrical wall.

By arranging these two types of connecting bodies 6 alternately in the axial direction of the excavated hole, the main wall portion 1a
, lb, arcuate plate-shaped steel segments 4 are arranged in a staggered manner.

In this way, the reason why the arc plate steel segments 4 are arranged in a staggered manner in the main wall portions 1 a and 1 b is because if they are not arranged in a staggered manner, the longitudinal length of the arc plate steel segments 4 will be The joint surface at the end face in the force direction,
In other words, the joint surfaces parallel to the axial direction of the excavated hole now exist on one plane, causing problems in the connection strength of the lining cylindrical wall and reducing the stability of the cylindrical wall. This is to do so.

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

As a solution to the above problem, two connecting arms 7, 7
A cylindrical wall body for lining has been proposed that uses branch segments having different lengths (hereinafter referred to as different arm branch segments).

A cylindrical wall body for lining using this different arm branch segment is shown in FIG. The lining tubular wall shown in FIG. 8 is different from that shown in FIG. 7 in that the key segment 5 located adjacent to the branch segment 2 shown in FIG. In the figure, it is a point that is integrated with the longer connecting arm 7a of the two connecting arms of the different arm branch segment 9.

In this way, the long connecting arm 7a, the connecting arm 7 and the base 8
By using the different arm branch segment 9 consisting of the above, it becomes possible to construct the lining tubular wall body without using the key segment 5, and the above-mentioned problem of increasing the number of types of segments can be solved. can.

``Problems to be Solved by the Invention'' By the way, the main girder of the above-mentioned arcuate plate-shaped steel segment 4 is made of a steel plate with an arcuate planar shape called a flat bar.
It is shaped by cutting perpendicular to its longitudinal direction.

Therefore, this flanotober is used in large quantities, and is mass-produced and provided at a relatively low cost. When forming the branch main girder, which is a member of the branch segment 2, an attempt was made to use the above-mentioned flanto bar because it could be supplied at a low cost, but the shape of the branch main girder did not match the shape of the flanto bar Due to the large difference, it was impossible to use this flat bar. For this reason, the branch main girder is usually formed by cutting a steel plate. Even when the branch main girder was formed by cutting the steel plate in this manner, the manufacturing cost did not increase because the branch main girder had a relatively small shape.

However, when the branch main girder of the different arm branch segment 9 is formed by cutting from the W4 plate, there is a problem in that the manufacturing cost becomes extremely high due to its large shape.

Furthermore, since the shape of the branch main girder is significantly different from that of a flat bar, it is impossible to form a branch segment using the flat and top bars as they are.

The present invention has been made in view of the above circumstances, and is capable of reducing the number of types of segments used when constructing a cylindrical wall for lining an excavation hole, and which can be manufactured at low cost. The purpose is to provide a partial segment.

"Means for Solving the Problem" In the present invention, the lengths of the two arms connected to the circular arc plate-shaped steel segment are different from each other, and the lengths of the two arms are shortened. The above-mentioned problem is solved by using a different arm bifurcation segment that is composed of a common base having the length of the arm and an extended arm connected to one of the arms of the common base.

"Operation" By configuring the different arm branch segment from a common base and an extended 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. It is relatively inexpensive due to its large size, and the extension arm that forms the R arm branch segment together with the common base uses a member obtained by cutting a commonly used flat bar as its main girder. It can be manufactured at low cost. Therefore, the manufacturing cost of the different arm bifurcation segment does not increase.

"Example" Hereinafter, the different arm bifurcation segment of the present invention will be described in detail.

As mentioned above, the feature of the different arm bifurcation segment of the present invention is that the different arm bifurcation segment is composed of a common base and an extended arm.

First, an example of the common base will be explained using FIG. 1. Reference numeral 10 in the figure indicates the common base. The common base 10 is approximately Y-shaped in appearance and consists of two short arms 11, 11 and a base l2, and the two are provided facing each other.
Plate-shaped common base main girder whose planar shape is approximately Y-shaped +
3, 1 3 and this common base main girder! A common base joint provisional 15 provided between one end surface of the arm body 14,1/l of 3,+3, that is, at the end of one arm 2, and near the na:14 surface of the base 12, Intermediate column joint temporary l6 installed between the common 2^ section main girders 13 and 13 perpendicular to the common base main girder 13
and the plane provided between the two end surfaces of the arm portions 1 l and t 1, which is opposite to the end surface of the base 12, has a rectangular shape, and the side surface has a circular shape. It is generally composed of an arcuate common base skin plate 17.

Next, the extension arm portion joined to the common base portion 10 will be explained using FIG. 2. Reference numeral 4 in the figure indicates an arcuate plate-shaped steel segment.

The arc plate-shaped steel segment 4 has joint plates 19, l9 at both ends of the pair of arc-shaped main girders 18, 18, respectively.
Attach these main girders 18, 18 and joint plates 19, +9
A skin plate 20 is welded to the outer periphery of an arcuate rectangular body formed by the above, and a rib 2l is further welded to the circumferential surface of the skin plate 20. Hi on top of this
18 is obtained by cutting a planar or arcuate steel plate, usually called a flantobar, into a predetermined length.

The main girder of the extension arm used in the present invention (hereinafter referred to as the extension arm main girder) is preferably formed using this flannel bar from the viewpoint of manufacturing cost.
Like 8, it is preferable to cut the flap and tonneau to a predetermined length perpendicularly to the longitudinal direction thereof. Here, in order to assemble the rigid plate-shaped steel segments 4 in a staggered manner in the cylindrical wall, it is necessary to make the lengths of the extended arm main girder and the main girder l8 different.

An example of the different arm bifurcation segment of the present invention will be explained using FIG. 3. This different arm bifurcation segment includes the common base 10 which is approximately Y-shaped in appearance, and the extended arm 2 which is shaped like an arc plate.
It is composed of 2. This extension arm 22
is a pair of arc-shaped extended arm main girders 23, 23, a skin plate 20 joined to the outer peripheral surface of the extended arm main girders 23, 23, and one end surface of the extended arm main girders 23, 23. The joint plate 19 of the main extension arm portions NT23, 23 is joined to the common base 10 at the end surface where the joint plate 19 is not joined. This extended arm main girder 23 is formed by cutting the above-mentioned flanotoher perpendicularly to its longitudinal direction, and connects one end surface in the longitudinal direction to the end of the arm l4 of the common base main '6j13. In addition, the inner peripheral side surface of the extended arm main girder 23 is welded to the base 12 side of the common base 10 by one vertical rib 24.

A method of joining the end face of the extended arm main girder 23 and the end face of the arm body 14 of the common base main girder 13 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.
4 or the mutually opposing portions of the two joints 25, 25 between the end surfaces of the arm bodies 1 4, 1 4 and the longitudinal end surfaces of the extended arm main girders 23, 23, respectively. It is arranged like this. After being arranged in this manner, the longitudinal ribs 24 are welded to the extension arm main girders 2 3, 2 3 and the arm bodies l4, 14 on both sides of each of the two side surfaces.

Figure 5 shows the details of the arm bodies 14, 14 and the main girder 23 of the extended arm part.
, 23 and 23 are welded in a butted state. In the mutually facing portions of the two joint portions 25, 25, a groove having a square cross section is provided in advance by cutting or the like. The arm bodies 14, 14 and the extended arm main girders 23, 23 are respectively joined by welding the ■-shaped grooves.

FIG. 6 shows an example in which a rectangular plate-shaped contact plate 26 is used and joined by welding. The pads 11i 226, 26 are arranged so that the two mutually parallel side surfaces of the pad plate 26 are parallel to the joint 25, and the surfaces thereof cover the joint 25, in the mutually opposing portions of the joints 25, 25. After that, it is welded to the extension arm main girder 23 and the arm l4, respectively, on the two mutually parallel side surfaces.

Although the method of joining the extended arm main girder 23 and the arm l4 of the common base 10 has been described above, the present invention is not limited to the above joining method.

"Effects of the Invention" The present invention provides a 7IX arm branch segment in which the lengths of the two arm parts connected to the arcuate plate-shaped steel segment are 5z each, and the length of the two arm parts is the length of the short arm part. This is a different arm bifurcation segment characterized by being composed of a common base and an extended arm that is joined to one of the arms of this common base. The main spar of the base is the same size as the main spar of a conventional branch segment and is relatively inexpensive. In addition, the extended arms that together with the common base constitute different arm bifurcation segments,
By using a member obtained by cutting a commonly used flat bar as the main girder, it can be manufactured at low cost. Therefore, the present invention has the effect that different arm bifurcation segments can be manufactured at low cost, in which arc plate-shaped steel segments can be assembled in a staggered manner without using key segments in a cylindrical wall body.

[Brief explanation of the drawing]

FIG. 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 the extension arm used in the present invention, and FIG.
The figure is a partially sectional schematic perspective view showing an example of the present invention, FIGS. 4 to 6 are schematic perspective views showing examples of joining the common base and the extension arm, and FIGS. 7 and 8. FIG. 1 is a schematic perspective view showing a conventional cylindrical wall for lining. 1 a, '1 b...Main wall portion, 2...Branch segment, 4...Circular plate-shaped steel segment, 10.
... Common base, 11 ... Arm part, 22 ・
... Extended arm.

Claims (1)

[Claims] A C-shaped cross-sectional structure composed of a plurality of arc plate-shaped steel segments assembled along the circumferential wall of two drilled holes with circular cross-sections that partially overlap each other. A different arm branching part that connects the main wall part and the main wall part having an inverted C-shaped cross section at their upper and lower ends, and in which the two arm parts connected to the arcuate plate-shaped steel segment have different lengths. In the segment, the above-mentioned different arm bifurcation segment is composed of a common base in which the length of the two arms is the same as the length of the short arm, and an extended arm connected to either one of the arms of this common base. Different arm bifurcation segment characterized by