JP3447155B2 - Seismic isolation structure of overlapping circular shield segments - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation structure for overlapping circular shield segments.

[0002]

2. Description of the Related Art In the case of a box culvert type underground tunnel used for a subway tunnel, for example, an unexpected large-scale seismic force may cause a large damage to the center pillar. It is considered that this is because the shear stress and bending moment due to the earthquake are concentrated on the center column and the eccentric load acts.

On the other hand, as shown in FIG. 6, a shield lining structure having an overlapping circular cross section has upper and lower Y-shaped joints for connecting a pair of left and right segment bodies 1 whose circular cross sections partially overlap each other. Stability is maintained by having a structure in which the middle pillar segments 3 are connected between the segments 2.

The center pillar segment 3 is a member having a predominant axial force in order to bear a vertical load, and its member cross section is determined mainly by the compressive force applied thereto. Further, the joint portion between the joint segment 2 and the middle pillar segment 3 is conventionally rigidly connected, and has a structure having bending rigidity.

Compared with the above-mentioned box culvert type underground tunnel, this overlapping circle shield segment is constructed by fastening each segment with bolts, and therefore has a flexible structure for small and medium-scale earthquakes. Was said to have sufficient durability.

[0006]

However, in the event of an unexpected large-scale earthquake, since the central pillar segment 3 is rigidly connected to each segment body 1 through the joint segment 2, the cover It may hinder the characteristics of the seismic isolation structure of the entire work.

Therefore, in order to improve the seismic resistance against this kind of unexpected large-scale earthquake, the rigidity of the segment body is increased and the rigidity of the joint portion is increased to increase the resistance during the earthquake. Although it is possible to reduce the force acting on time, in the former case, there is a limit in terms of economic efficiency, and when reinforcing the existing shield, an extremely large amount of work is required, which is not always a realistic method. is not.

It is an object of the present invention to provide a seismic isolation structure for overlapping circle shield segments which can cope with a large-scale earthquake by reducing the latter acting force during an earthquake.

[0009]

The present invention has been made to achieve the above object, and the invention according to claim 1 is
A part of a plurality of circular cross sections formed by assembling the segment main bodies overlap each other, and a joint segment connecting the segment main bodies is arranged at an upper and lower position corresponding to the overlapping portion, and the upper and lower joint segments are centered. In the overlapping circular shield segment connected by a pillar segment, a seismic isolation device is interposed between the upper and lower joint segments and the middle pillar segment, respectively.

Further, according to a second aspect of the present invention, a part of a plurality of circular cross sections formed by assembling the segment main bodies overlap each other, and the joints connecting the segment main bodies to each other at the upper and lower positions corresponding to the overlapping portions. While placing the segments, in the overlapping circle shield segment connecting the upper and lower joint segments with a middle pillar segment, one of the upper and lower joint segments,
The seismic isolation structure of the overlapping circular shield segment is characterized in that a seismic isolation device is interposed between the center pillar segment.

Further, according to a third aspect of the present invention, a part of a plurality of circular cross sections formed by assembling the segment main bodies overlap each other, and the joints connecting the segment main bodies to each other at the upper and lower positions corresponding to the overlapping portions. Seismic isolation of the overlapping circular shield segment, characterized in that a seismic isolation device is interposed in the middle portion of the middle pillar segment in the overlapping circular shield segment in which the segments are arranged and the upper and lower joint segments are connected by the middle pillar segment. In structure.

According to the seismic isolation structure of the overlapping circular shield segment of the present invention having each of the above-mentioned constitutions, the seismic isolation device interposed between the joint segment and the central pillar segment or in the middle portion of the central pillar segment is used. It is possible to improve the seismic resistance of the segment by absorbing the shearing force and bending moment generated in the segment during an earthquake.

[0013]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be noted that, except for the main part of the present invention, it is the same as the prior art, and therefore, the same reference numerals are used for the same portions, and different reference numerals are used only for newly added portions.

1 to 3 show a first embodiment of the present invention. The overlapping circle shield segment in the figure is similar to the conventional one, and the middle pillar segment 3 is provided between the upper and lower Y-shaped joint segments 2 which connect the pair of left and right segment bodies 1 whose circular cross sections partially overlap each other. It is a connected structure.

In addition to this, in the present invention, a laminated rubber plate 10 as a seismic isolation device is integrally interposed between the middle pillar segment 3 and the upper and lower joint segments 2.
The laminated rubber plate 10 is formed by alternately laminating a large number of iron plates and hard rubber plates, and can obtain any designed shear rigidity and compression rigidity according to the material, cross section, and number of layers.

As a mounting structure of the laminated rubber plate 10, as shown in FIGS. 2 and 3, a thick flange plate 12 made of a steel plate or the like is provided on the joint surface of the laminated rubber plate 10 to the joint segment 2. The through holes 14 are formed integrally with each other, and the bolt through holes 14 are formed at the four corners thereof.
The pair of grooves 16 for passing the bolts corresponding to No. 4 are cut out.

Therefore, each flange plate 12 of the laminated rubber plate 10 fixedly integrated with both ends of the middle pillar segment 3 in advance.
To the central lower surface and the upper surface of the joint segment 2 so that the through holes 14 are aligned with the grooves 16 and the bolts 18 are arranged in the grooves 16 from the side surfaces of the joint segment 2 and the ends thereof are inserted into the through holes 14 of the flange plate 12. The nut 20 is screwed into the lower projecting end by inserting it into the bottom, and the nut 20 is screwed into the lower protruding end so that the middle pillar segment 3 can be easily connected between the upper and lower joint segments 2 with the laminated rubber plate 10 interposed. You can

In the above structure, in the normal state, the center pillar segment 3 shares the axial force in the vertical direction via the laminated rubber plate 10 and supports the entire lining with an appropriate compression rigidity.

When an unexpected large-scale earthquake occurs from this state, the horizontal shearing force and bending stress generated between the upper and lower parts of the middle pillar segment 3 and the joint segment 2 are absorbed by the deformation of each laminated rubber plate 10. As a result, seismic isolation characteristics will be provided.

FIG. 4 shows a second embodiment of the present invention, in which the seismic isolation device is constructed only between the upper part of the middle pillar segment 3 and the lower part of the joint segment 2 located above. The laminated rubber plate 10 is interposed, and the lower end side of the middle pillar segment 3 is connected to the central upper portion of the joint segment 2 by a mounting structure similar to the conventional one.

In this embodiment, since the laminated rubber plate 10 is interposed only in the upper part, the mounting structure can be changed only in the upper part for mounting, and the structure is simplified. Also,
As described above, the laminated rubber plate 10 can obtain arbitrary shear rigidity and compression rigidity according to the material, cross section, and number of laminated layers. Seismic isolation characteristics similar to those of the embodiment will be provided.

Although not described, it is needless to say that the laminated rubber plate 10 can be interposed only on the lower side, contrary to the above.

FIG. 5 shows a third embodiment of the present invention, in which the middle of the middle pillar segment 3 is vertically divided into two parts, and the laminated rubber plate 10 is interposed therebetween. In this case, since the connection between the middle pillar segment 3 and the joint segment 2 may be the same mounting structure as the conventional one, in order to apply the present invention to the existing joint segment 2,
When the middle pillar segment 3 is replaced, the work can be performed without changing the attachment structure with the joint segment 2, and the replacement work is simple and highly compatible.

[0024]

As described above, according to the seismic isolation structure of the overlapping circular shield segment of the present invention, the seismic isolation device interposed between the joint segment and the center column segment or in the middle portion of the center column segment is used. Since the shearing force and bending moment generated in the segment during an earthquake are absorbed, the seismic resistance of the segment against a large-scale earthquake can be easily improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a seismic isolation structure of an overlapping circle shield segment according to a first embodiment of the present invention.

FIG. 2 is an enlarged view taken along arrow A in FIG.

FIG. 3 is an exploded perspective view showing the assembly structure.

FIG. 4 is a cross-sectional view showing a seismic isolation structure of an overlapping circle shield segment according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a seismic isolation structure of an overlapping circle shield segment according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a structure of a conventional overlapping circle shield segment.

[Explanation of symbols]

1 segment body 2 joint segment 3 Middle pillar segment 10 Laminated rubber plate (seismic isolation device)

Claims (3)

(57) [Claims] 1. A plurality of circular cross-sections formed by assembling segment main bodies overlap each other, and joint segments for connecting the segment main bodies are arranged at upper and lower positions corresponding to the overlapping portions, and In the overlapping circular shield segment in which the joint segment of (1) is connected by a central pillar segment, a seismic isolation device is interposed between the upper and lower joint segments and the central pillar segment, respectively. 2. A plurality of circular cross sections formed by assembling the segment main bodies overlap each other, and joint segments for connecting the segment main bodies are arranged at upper and lower positions corresponding to the overlapping portions, and In the overlapping circular shield segment in which the joint segments of the above are connected by a central pillar segment, a seismic isolation device is interposed between one of the upper and lower joint segments and the central pillar segment. Quake structure. 3. A plurality of circular cross sections formed by assembling the segment main bodies overlap each other, and joint segments for connecting the segment main bodies are arranged at upper and lower positions corresponding to the overlapping portions, and In the overlapping circular shield segment in which the joint segments of (1) are connected by a central pillar segment, a seismic isolation device is interposed at an intermediate portion of the central pillar segment.