JP4050882B2 - Segment ring structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention constructs an internal space between adjacent existing tunnel segment structures, removes a segment facing the internal space of the existing tunnel segment structure, and joins the internal structure built in the internal space and the existing tunnel segment This is a technique related to the segment ring structure of the tunnel widening portion when the tunnel cross section is enlarged.
[0002]
[Prior art]
When two or more adjacent existing tunnel cross sections as shown in FIG. 1 are widened to complete the wide section tunnel cross section as shown in FIG. 4, the following steps are performed.
[0003]
(1) A new space 9 is constructed between a plurality of existing segment tunnels 6.
As shown in FIG. 2, the space 9 between the existing tunnel segments 6 is sandwiched between the existing tunnel segments 6 while constructing a retaining wall 7 such as a steel sheet pile, a supporting material 8a, and an erection material 8b from the ground surface. The excavation method that removes and removes the earth and sand in the area, and as shown in FIG. 3, the freezing pipe is inserted into the ground so as to surround the space 9 to be constructed from the existing tunnel segment 6, and the surrounding ground is A non-open-cutting method or the like that leaves the frozen soil 10 and excludes the enclosed earth and sand is common.
[0004]
(2) The removal part segment 1 of the existing tunnel segment 6 facing the constructed space is removed. In that case, since a partial load due to the construction of the internal space acts on the remaining segment 2, measures are taken to reinforce the remaining segment 2 such as placing a support (not shown) in the tunnel in advance.
[0005]
(3) And, in the constructed internal space, the internal structure 4 including the floor 4a and the middle pillar 4b made of reinforced concrete, steel, or steel reinforced concrete is constructed, and the remaining portion segment 2 and the internal structure 4 are connected to each other. As a result, the wide section tunnel cross section as shown in FIG. 4 is completed.
[0006]
Here, in order to simplify the on-site assembly management of the segment, the segment used for the existing tunnel segment 6 is generally unified in the segment structure and the segment specification regardless of the part in the same segment ring.
[0007]
[Problems to be solved by the invention]
Two or more adjacent existing tunnel sections are widened by excavating the ground between the existing tunnel segments 6 from the ground surface or from within the tunnel section to form a new internal structure 4 and a removal segment facing the internal structure 4 1 is removed, and the internal structure 4 and the remaining segment 2 are connected to each other. Therefore, from the viewpoint of construction and performance, a steel segment that is easy to disassemble and has a light product weight is suitable as the segment structure of the removal portion.
[0008]
However, in the general segment ring structure described above, since the segment structure and the segment specifications are unified in the same segment ring, all of the tunnel widening section segments are formed of steel segments and the most in the tunnel cross section. Segment specifications will be determined under strict design conditions.
[0009]
Therefore, even though the cross-sectional force normally generated in the tunnel cross section varies depending on the tunnel part, if the segment structure and specifications are determined by this method, a segment with a segment structure and specifications exceeding the required proof stress will occur depending on the part. The design is irrational or uneconomical.
For example, the removal portion segment 1 is required to have a segment structure suitable for the removal operation, and the remaining portion segment 2 is desirably a safe and economical segment structure during and after the tunnel widening.
[0010]
On the other hand, for the purpose of widening the opening in the tunnel cross section in the tunnel axis direction in the tunnel cross section in JP-A-9-317392, the middle column portion and the segment portion connected to the middle column portion are made of steel having a high yield strength, There is a description of a multiple tunnel structure in which the segment is made of concrete.
In this method of Japanese Patent Laid-Open No. 9-317392, a plurality of tunnel segments are joined by a connecting portion segment and a middle pillar, and the completed tunnel cross-section outer peripheral portion is a tunnel cross-section composed only of segments, The middle pillar is made of metal and the other segments are made of concrete.
[0011]
In the case of the above publication, generally, a case where a tunnel connection structure including a connection portion is constructed in advance in parallel with shield excavation is targeted. Therefore, after constructing a plurality of tunnel segments, when removing a part of the existing tunnel segment and constructing the wide section tunnel cross-section by joining with the separately constructed internal structure, the preconditions differ, so It is difficult to apply this technology.
[0012]
The present invention has been made to solve the above-described problems, and provides an economical segment lining structure for tunnel lining while satisfying the required performance of each part of the tunnel without obstructing the construction of the tunnel widening portion. This is the issue.
[0013]
[Means for Solving the Problems]
The gist of the present invention is that an internal structure formed between two existing tunnel segments by removing a part of two or more adjacent existing tunnel segments facing each other as described in claim 1. A segment ring structure used for a tunnel widening portion when expanding a tunnel cross section by interconnecting with existing tunnel segments,
The segment ring structure is composed of a plurality of segments in the same segment ring,
The removal part segment removed at the time of widening is an iron-based segment, and the remaining part segment left in the tunnel widening part is a concrete-filled iron-based segment,
When the segment ring is formed , the remaining segment in the vicinity of the connecting portion with the internal structure has a large thickness of the main girder so that each remaining segment has an appropriate yield strength according to the tunnel part during and after widening. By increasing the strength of the main girder steel plate or by increasing the strength of the main girder steel plate, the remaining segment of the tunnel part other than the vicinity of the connecting portion is reduced in thickness of the main girder plate thickness or the strength of the main girder steel plate. By making it low, the segment yield strength is set smaller than that of the remaining segment in the vicinity of the connecting portion .
[0014]
A second aspect of the present invention is an internal structure formed between existing tunnel segments by removing a part of two or more adjacent existing tunnel segments facing each other as described in claim 2. A segment ring structure used for a tunnel widening portion when expanding a tunnel cross section by interconnecting with existing tunnel segments,
The segment ring structure is composed of a plurality of segments in the same segment ring,
The removal part segment removed at the time of widening is an iron-based segment, and the remaining part segment left in the tunnel widening part is a reinforced concrete segment,
At the time of widening and after widening, the remaining segment in the vicinity of the connecting portion with the internal structure increases the diameter of the reinforcing bar so that each remaining segment has an appropriate strength corresponding to the tunnel part. Or by increasing the reinforcing bar strength or concrete strength, the segment strength is set to be large, and the remaining part segment of the tunnel part other than the vicinity of the connecting part is to reduce the reinforcing bar diameter or reduce the reinforcing bar strength or concrete strength. Therefore, the segment yield strength is set smaller than that of the remaining portion segment in the vicinity of the connecting portion . Here, the iron-based segment refers to a metal segment manufactured by welding and assembling a steel plate or casting.
[0015]
According to a third aspect of the present invention, as described in claim 3, an internal structure formed between existing tunnel segments by removing a part of two or more adjacent existing tunnel segments facing each other. A segment ring structure used for a tunnel widening portion when expanding a tunnel cross section by interconnecting with existing tunnel segments,
The segment ring structure is composed of a plurality of segments in the same segment ring,
The removal part segment removed at the time of widening is an iron-based segment, and the remaining part segment left in the tunnel widening part is a steel concrete composite structure segment,
When the segment ring is formed, the remaining segment in the vicinity of the connecting portion with the internal structure has a large thickness of the main girder so that each remaining segment has an appropriate yield strength according to the tunnel part during and after widening. By increasing the strength of the main girder steel plate, increasing the strength of the reinforcing bar, or increasing the strength of the reinforcing bar or concrete, the segment strength is set large. The remaining part segment is left in the vicinity of the connecting part by reducing the thickness of the main girder plate or lowering the strength of the main girder steel sheet, or reducing the diameter of the reinforcing bar used or reducing the strength of the reinforcing bar or concrete. The segment proof stress is set to be smaller than that of the partial segment .
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The cross-sectional force generated in the tunnel cross section generally varies greatly depending on the tunnel circumferential direction portion. In particular, in a large cross section such as a tunnel widened portion, the difference in generated cross-sectional force depending on the region tends to be significant. Therefore, the present invention does not unify the segment specifications within the same segment ring, changes the segment structure between the removal part and the remaining part, and reflects the cross-sectional force at each part of the tunnel when the tunnel is widened in the remaining part. Use individual segments.
[0017]
FIG. 5 shows an example of the segment ring structure of the widened portion according to the present invention.
The removal section segment 1 is dismantled in the existing tunnel or in the internal space, and the dismantled segment is carried out to the ground. The disassembly of the segment corresponding to the predetermined removal part is performed by removing the joint bolts 14 and 15 between the fastened segments and cutting the segment at a predetermined position. Is suitable. That is, when disassembling a concrete filling segment or a reinforced concrete segment, the concrete is removed in advance, and then the steel plate or the reinforcing bar is cut. Therefore, the field work becomes complicated and is not suitable for the removal portion. Also, from the viewpoint of on-site handling and carrying out on the ground, concrete that is heavy in weight is an adverse effect of the removal work.
[0018]
On the other hand, the remaining segment 2 is not an object to be removed, so that concrete does not cause any adverse effects on construction. Rather, in the case of secondary lining, especially in iron-based segments, concrete will be placed on site after segment assembly. From the point of field work, concrete filled with segmented concrete in advance is filled inside the segment lining. The filling segment is advantageous in terms of shortening the construction period.
Further, if the remaining portion segment 2 is a concrete filling segment, it is possible to cope with a design method in which the anticorrosion / fire resistance measures in a road tunnel or the like are dealt with by concrete.
Furthermore, by filling the remaining portion segment 2 with filling concrete, the steel weight of the main girder of the segment can be reduced. Steel sheets such as main girders of iron-based segments are designed in consideration of the influence of out-of-plane buckling, and therefore the steel sheet thickness is designed to satisfy a predetermined width-thickness ratio. It is necessary to increase the thickness. However, since the out-of-plane buckling of the steel sheet is suppressed by filling the iron-based segment with the inside-filled concrete, the steel sheet can be designed without considering the out-of-plane buckling, and the steel sheet can be thinned.
[0019]
In addition, by determining the segment specifications so as to satisfy the required proof strength according to the tunnel site, it is possible to appropriately change the segment specifications such as the main girder plate thickness of the widened portion and the remaining portion as shown in FIG. Become. The iron-based segment 11 of the removed portion determines the main girder plate thickness and the like according to the segment strength required until the tunnel widening stage. Further, in the cross section of the widened portion, the cross-sectional force in the vicinity (16, 17) of the connecting portions 20 and 21 between the internal structure 4 and the remaining segment 2 is large, and the generated cross-sectional force is small in the other tunnel portions. Accordingly, the segments 16 and 17 in the vicinity of the connecting portions 20 and 21 of the remaining portion segment 2 with the internal structure 4 are thick main girders having a large segment strength, while the other segments 18 are segment specifications such as thin main girders. can do.
[0020]
【Example】
FIG. 5 shows an embodiment of the segment ring structure of the widened portion according to the present invention.
The removal part segment 1 can be an iron-based segment 11, and the remaining part segment 2 can be a concrete-filled iron-based segment 12, a reinforced concrete segment, or a steel-concrete composite segment.
Here, the iron-based segment refers to a general metal segment manufactured by welding or assembling a steel plate or casting.
[0021]
Since the segment specifications can be determined so as to satisfy the required proof stress according to the tunnel site as described above, as shown in FIG. 6, the cross-sectional force is large in the vicinity of the junction between the internal structure and the remaining segment, The tunnel parts 16 and 17 are dealt with by increasing the thickness of the main girder plate or increasing the strength of the main girder steel sheet, and conversely, since the cross-sectional force is small at the tunnel part 18 other than the vicinity of the joint, the thickness of the main girder plate is reduced. The strength of the main girder steel plate can be reduced. Similarly, when a reinforced concrete segment is used as the remaining segment 2, the used reinforcing bar diameter, reinforcing bar strength, concrete strength, or the like is selected to have a predetermined appropriate strength.
[0022]
As shown in FIG. 5, a segment joint 24 as shown in FIGS. 7 and 8 is provided in the vicinity of the boundary portion 14 between the removal portion segment 1 and the remaining portion segment 2 so that the removal operation can be easily performed. When the removal portion segment 1 is removed, the segments can be disassembled by removing the bolts of the segment joint bolt hole 26 and the ring joint bolt hole 25, and the removal work becomes easy.
[0023]
FIG. 7 shows an example of the iron-based segment 11 for the removal portion, and FIG. 8 shows an embodiment of the concrete-filled iron-based segment 12 for the remaining portion.
The iron-based segment 11 for the removal portion is provided with an appropriate number of vertical ribs 23 so as to withstand the shield machine propulsion reaction force during shield excavation. The plate thickness of the main girder 22 is designed to withstand the load up to the time of tunnel widening.
[0024]
The concrete-filled iron segment 12 for the remaining portion is filled with a medium-filled concrete 27 at a height that covers the height of the segment main girder. Since the shield machine propulsion reaction force at the time of shield excavation is transmitted by the filling concrete 27, the number of longitudinal ribs can be reduced or the plate thickness can be reduced as compared with the case of using an iron-based segment.
[0025]
When implementing the present invention, unlike the conventional segment assembly management, it is necessary to select a segment having an appropriate specification for each tunnel part and ensure that it is installed at a predetermined part. For this reason, simple devices such as clearly specifying each part of the tunnel and the type of segment specification in the segment product and appropriately performing assembly management at the site are desired.
[0026]
【The invention's effect】
According to the present invention, the segment ring structure satisfies the required performance required by the tunnel part without interfering with the construction of the widened portion of the tunnel, and the segment structure configured in the segment ring is configured differently. By making the segment specification according to the part, the steel weight of the segment ring structure can be reduced, and the effect of reducing the overall construction cost of the tunnel appears.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a tunnel widening portion.
FIG. 2 is a construction drawing of a tunnel widening portion by an excavation method.
FIG. 3 is a construction drawing of a tunnel widening portion by a non-opening method.
FIG. 4 is a completed view of a tunnel widening portion.
FIG. 5 is a diagram showing an embodiment of a segment ring structure of a tunnel widening portion.
FIG. 6 is a diagram showing an example of a segment ring structure of a tunnel widening portion.
FIG. 7 is a diagram showing a structure of an iron-based segment.
FIG. 8 is a view showing the structure of a concrete-filled iron-based segment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Removal part segment 2 Remaining part segment 3 Connection part 4 Internal structure 4a Floor 4b Middle pillar 6 Existing tunnel segment 7 Earth retaining material 8a Support material 8b Raising material 9 Space (internal space)
10 Frozen earth 11 Iron-based segment 12 Concrete-filled iron-based segment 14 Removal / remaining portion inter-segment joint 15 Inter-segment joint 16 Upper remnant thick-walled main girder concrete Stuffed iron-based segment 17 Lower remnant-thick main girder concrete Stuffed iron-based segment 18 Remaining thin-walled main girder concrete Filled iron-based segment 20 Upper connecting segment 21 Lower connecting segment 22 Main girder 23 Vertical rib 24 Segment joint 25 Ring joint bolt hole 26 Segment joint bolt hole 27 Filled concrete 28 Reinforcing bar 29 Joint bolt box

Claims (3)

Tunnel widening when the tunnel cross-section is expanded by removing the mutually facing part of two or more existing tunnel segments and interconnecting the internal structure formed between the existing tunnel segments and the existing tunnel segments A segment ring structure used for a part,
The segment ring structure is composed of a plurality of segments in the same segment ring,
The removal part segment removed at the time of widening is an iron-based segment, and the remaining part segment left in the tunnel widening part is a concrete-filled iron-based segment,
When the segment ring is formed , the remaining segment in the vicinity of the connecting portion with the internal structure has a large thickness of the main girder so that each remaining segment has an appropriate yield strength according to the tunnel part during and after widening. By increasing the strength of the main girder steel plate or by increasing the strength of the main girder steel plate, the remaining segment of the tunnel part other than the vicinity of the connecting portion is reduced in thickness of the main girder plate thickness or the strength of the main girder steel plate. The segment ring structure is characterized in that the segment proof strength is set to be smaller than that of the remaining portion segment in the vicinity of the connecting portion by lowering . Tunnel widening when the tunnel cross-section is expanded by removing the mutually facing part of two or more existing tunnel segments and interconnecting the internal structure formed between the existing tunnel segments and the existing tunnel segments A segment ring structure used for a part,
The segment ring structure is composed of a plurality of segments in the same segment ring,
The removal part segment removed at the time of widening is a steel-based segment, and the remaining part segment left in the tunnel widening part is a reinforced concrete segment,
At the time of widening and after widening, the remaining segment in the vicinity of the connecting portion with the internal structure increases the diameter of the reinforcing bar so that each remaining segment has an appropriate strength corresponding to the tunnel part. Or by increasing the reinforcing bar strength or concrete strength, the segment strength is set to be large, and the remaining part segment of the tunnel part other than the vicinity of the connecting part is to reduce the reinforcing bar diameter or reduce the reinforcing bar strength or concrete strength. The segment ring structure is characterized in that the segment yield strength is set smaller than that of the remaining portion segment in the vicinity of the connecting portion . Tunnel widening when the tunnel cross-section is expanded by removing the mutually facing part of two or more existing tunnel segments and interconnecting the internal structure formed between the existing tunnel segments and the existing tunnel segments A segment ring structure used for a part,
The segment ring structure is composed of a plurality of segments in the same segment ring,
The removal part segment removed at the time of widening is an iron-based segment, and the remaining part segment left in the tunnel widening part is a steel concrete composite structure segment,
When the segment ring is formed , the remaining segment in the vicinity of the connecting portion with the internal structure has a large thickness of the main girder so that each remaining segment has an appropriate yield strength according to the tunnel part during and after widening. By increasing the strength of the main girder steel plate, increasing the strength of the reinforcing bar, or increasing the strength of the reinforcing bar or concrete, the segment strength is set large. The remaining part segment is left in the vicinity of the connecting part by reducing the thickness of the main girder plate or lowering the strength of the main girder steel sheet, or by reducing the diameter of the reinforcing bar or reducing the strength of the reinforcing bar or concrete. Segment ring structure characterized in that the segment strength is set smaller than that of the segment .

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