JP6811299B1 - Segment set consisting of B segment and K segment, open tunnel and its construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct an open tunnel by installing a K segment at the end even if there is a construction error in the circumferential direction in the construction of an open tunnel connecting two tunnels arranged side by side. A segment, a B segment, an open tunnel and a construction method thereof are provided. SOLUTION: Of B segment 20B and K segment 20D constituting an open tunnel 700A connecting two tunnels 100 and 200 arranged side by side, between B segment 20B arranged on each tunnel 100 and 200 side. It is a K segment 20D that is inserted and installed, and at least one segment joint surface 27A (27B) of the K segment 20D is a first tapered surface that inclines in the radial direction. The radial height of the K segment 20D is higher than that of the B segment 20B on the left and right sides of the segment 20D. [Selection diagram] FIG. 8

Description

The present invention relates to a segment set consisting of a B segment and a K segment , an open tunnel, and a construction method thereof.

For example, when constructing a road tunnel in an urban area where soft ground is distributed, the excavation method is generally applied, but the excavation method has inherent problems such as noise, vibration, and traffic regulation during construction. .. In addition, since the space under the road in urban areas is congested with buried objects such as multiple subways and utility tunnels, the installation depth of tunnels to be newly constructed tends to be deep, and the installation depth tends to be deep. Deepening is directly linked to an increase in construction costs. Against this background, the number of cases where the shield method is applied when constructing road tunnels is increasing. By the way, in the construction of this road tunnel, in the construction of a general road tunnel, for example, it is sufficient to construct a main tunnel having a circular cross section by excavating one shield excavator. On the other hand, the construction of the confluence of road tunnels requires an extremely large-scale underground widening that covers each section of the main tunnel and the ramp tunnel, and various measures must be taken for the construction method. As an example of the construction method, there is a method of constructing a prepaid support by constructing an arc-shaped or straight pipe roof between two tunnels, a main tunnel and a ramp tunnel. After constructing this pre-supported support, the inside of the tunnel is supported by the support, and a part of the tunnel is removed while excavating directly under the pipe roof above, for example, a large cross-sectional space in the shape of a multiple arc is formed. To. Then, in the large cross-sectional space formed in this way, it is possible to construct a structure such as a junction of the road tunnel described above.

Here, a method of constructing this large-section tunnel will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a vertical cross-sectional view for explaining a construction method and a temporary structure of a junction of a road tunnel, and FIG. 2 is a construction method and a main structure for a junction of a road tunnel as in FIG. It is a vertical sectional view. In the construction method of the junction of road tunnels, first, a ramp tunnel 100 having a relatively small cross section and a main tunnel 200 having a relatively large cross section are constructed side by side at intervals in the ground. Both the main tunnel 200 and the ramp tunnel 100 are constructed by the shield method, and a plurality of segments 20 are connected in the ring direction to form a segment ring, and a plurality of segment rings are connected in the extension direction of the tunnel. A tunnel is formed over a predetermined extension. Each segment 20 includes a plurality of curved main girders 21 extending in the circumferential direction, a skin plate 24 welded to the outer peripheral surface of the main girder 21, and the main girder 21 at the circumferential end of the main girder 21. It has a joint plate 22 connected to the skin plate 24 by welding, and a vertical rib 23 that connects the main girders 21 to each other to reinforce the segment 20.
Next, in each tunnel of the ramp tunnel 100 and the main tunnel 200, a support pillar 60 (vertical support work) extending in the vertical direction starting from the intersection position with the pipe roof 300 is constructed. Next, a pipe roof 300 is bridged between both tunnels above the ramp tunnel 100 and the main tunnel 200. The pipe roof 300 has a ramp tunnel 100 as a starting tunnel, and extends from the ramp tunnel 100 to the front of the main tunnel 200, which is the reaching tunnel, with a curved line while sequentially propelling the steel pipe 30. The ramp tunnel 100 may be the arrival side tunnel, and the main line tunnel 200 may be the start side tunnel. Further, a straight pipe roof may be constructed. Also at the lower positions of the ramp tunnel 100 and the main tunnel 200, the lower pipe roof 300A indicated by the alternate long and short dash line is installed as needed. Then, at the lower positions of the ramp tunnel 100 and the main tunnel 200, a preceding temporary lower receiver 400 straddling between both tunnels is bridged. The support pillar 60 may be constructed after the pipe roofs 300 and 300A are bridged.
Although it is not a temporary structure, an upper diagonal support 70 and a lower diagonal support 80 are constructed at the temporary stage in the ramp tunnel 100 and the main tunnel 200, respectively. All of these members are located on the outer peripheral side of the building limit in the drawing, and can be members buried in concrete or the like constructed on the outer peripheral side of the building limit. The upper diagonal support 70 extends in the direction along the axis of the main tunnel 700 (or the expansion tunnel) indicated by the alternate long and short dash line in the figure, and exerts an axial force acting from the tunnel 700 after the main tunnel is put into service. It is a member to escape. On the other hand, the downward diagonal support 80 is also a member that extends in the direction along the axis of the main tunnel 700 shown by the alternate long and short dash line in the drawing to release the axial force acting from the tunnel 700 after the main tunnel is put into service.
Of the main line tunnel 200 and the ramp tunnel 100, a recess 20a is provided in advance with respect to the segment 20 at a position where the end portion of the preceding temporary lower receiver 400 is fitted. For example, the recess 20a is made of concrete or the like at the beginning of tunnel construction. It is blocked by. Details of the construction method will be omitted, but for example, a digging machine having a bending mechanism and having a bending mechanism and capable of curved construction is started from the recessed portion 20a (starting portion) of the ramp tunnel 100, and the steel pipe 50 is propelled while digging the ground. By executing the above and connecting the steel pipes 50 to each other, the preceding temporary lower support 400 is constructed. In this construction, the excavator applied to the propulsion of the steel pipe reaches the recessed portion 20a of the main tunnel 200, completes the construction of the preceding temporary lower receiving 400, and then reduces the diameter, for example, to reduce the diameter of the preceding temporary lower receiving 400. It is pulled back into the starting tunnel 100 through the inside of the plurality of steel pipes 50 and collected. Further, in the main tunnel 200 and the ramp tunnel 100, recessed portions 20b and 20c are provided in advance in the segment 20 where the end portions of the cut-out tunnel 700 are connected.
On the starting side tunnel 100 side, among the plurality of steel pipes 30 constituting the pipe roof 300, they are fixed to the end 32 of the steel pipe 30 located at the rear end and the steel accommodating opening fixed to the segment 20. The connecting structure 600 of the pipe roof and the starting side tunnel is formed by the transmission member 10 or the cap member 17 and the concrete body 40 connecting the end portion 32 of the steel pipe 30 and the transmission member 10 or the cap member 17. .. On the other hand, on the reaching side tunnel 200 side, the steel pipe 30 whose tip 31 is stopped in front of the reaching side tunnel 200, the steel protruding portion protruding from the segment 20 into the ground G, and the tip 31 of the steel pipe 30. The connection structure 500 between the pipe roof and the reaching tunnel is formed by the concrete body 40 in which the steel body and the steel protrusion are involved and integrated.

Next, as shown in FIG. 2, a construction space SP is formed by digging a watermark below the pipe rule 300 and above the pipe rule 300A with the pipe rules 300 and 300A as support works, and a segment for the incision tunnel 700. The pipes are connected to the main tunnel 200 and the ramp tunnel 100 while being connected to each other via a joint portion. Here, the segment for the incision tunnel 700 is between the A segment 20A and the B segment 20B attached to the main line tunnel 200 or the ramp tunnel 100 side and the tapered end faces of the left and right B segments 20B from the construction space SP side. It is formed by a K segment 20C that is attached by being dropped (or inserted) in the X direction. The A segment 20A, the B segment 20B, and the K segment 20C as shown in FIG. 2 are connected to each other via a segment joint, and each segment is connected via a ring joint over the cut section to form a cut tunnel 700. Is formed.
After the main tunnel 200 and the ramp tunnel 100 are connected by the incision tunnel 700, a large cross-section tunnel is constructed by removing the area that interferes with the building limit inside both the main tunnel 200 and the ramp tunnel 100.

By the way, in the construction of the incision tunnel 700 shown in FIG. 2, the A segment 20A and the B segment 20B are constructed in the Y direction which is the circumferential direction of the incision tunnel 700 from the main line tunnel 200 side, and similarly in the circumferential direction from the ramp tunnel 100 side. After constructing the B segment 20B in the Y direction, the K segment 20C is finally dropped in the X direction, which is the radial direction, to form the structure in the circumferential direction shown in FIG. Then, the cut-out tunnel 700 is constructed by connecting a plurality of the structures in the circumferential direction over the extending directions of the tunnels 100 and 200 via the ring joints.
In the construction of this cut-out tunnel 700, if the gap in which the K segment 20C is finally dropped (or inserted) in the radial direction is constructed in an error-free manner, the K segment 20C is quickly dropped into the gap. , Bolts are inserted into a plurality of sets of bolt holes provided on the segment joint surfaces of both the B segment 20B and the K segment 20C, and bolted. Further, a seal groove is provided on the outer peripheral side of the segment joint surface of the B segment 20B and the K segment 20C, and the seal material is accommodated in both seal grooves, and both seal materials are compressed with each other. By abutting, a seal structure is formed.
However, if the gap in which the K segment 20C is finally dropped in the radial direction is constructed with an error (the gap is short in the circumferential direction or long in the circumferential direction), the B segment 20B and the K segment are constructed. There is a risk that the bolt holes cannot be aligned on both segment joint surfaces of 20C, and that the sealing materials cannot be brought into contact with each other.

Here, Patent Document 1 discloses a joint structure of a segment suitable for improving assembly accuracy, adjusting a misalignment, and a segment for adjusting a misalignment with respect to a joint of a bolt-joining type segment. Specifically, at least one joint surface is formed with a long hole bolt hole that intersects with a long hole bolt hole provided on the opposite joint surface of the segments to be joined to each other. This is a segment for adjusting differences. Further, in the joint structure of segments in which segments to be joined to each other are joined by bolts penetrating bolt holes provided on the respective joint surfaces, a bolt hole on one joint surface and a bolt hole on the other joint surface at the joint portion are joined. It is a segment joint structure in which the holes are elongated so as to intersect each other.

Japanese Unexamined Patent Publication No. 2007-56535

According to the joint structure of the segment and the misalignment adjustment segment described in Patent Document 1, it is possible to adjust the misalignment on the ring joint surface, but as described above, there is a construction error in the circumferential direction of the cut-out tunnel. Even in this case, it is not possible to solve the problem of installing the K segment at the end and constructing an open tunnel.

According to the present invention, in the construction of an open tunnel connecting two tunnels arranged side by side, even if there is a construction error in the circumferential direction, the K segment is finally installed to enable the construction of the open tunnel. It is an object of the present invention to provide a segment set consisting of a B segment and a K segment , an open tunnel, and a construction method thereof.

In order to achieve the above object, one aspect of the segment set consisting of the B segment and the K segment according to the present invention is:
Cut open constitutes a tunnel connecting the two tunnels juxtaposed, with each tunnel and B segments are arranged in side and a K segments disposed is inserted into the gap between the left and right of the B segment, B A segment set consisting of segments and K segments
At least one segment joint surface of the K segment is a first tapered surface that is inclined in the radial direction.
In the B segment, the segment joint surface that comes into contact with the first tapered surface of the K segment is a second tapered surface that is inclined in the radial direction.
In the circumferential direction of the cut open tunnel, the height of the radial direction of the K segment rather higher than the B segment on the left and right of the K segments,
The first segment joint bolt hole connected to the K segment, which is provided on the second tapered surface, is an elongated hole long in the radial direction of the B segment.
A second segment joint bolt hole for connecting to the B segment is provided on the first tapered surface.
The second segment joint bolt hole is positioned at a different position of the first segment joint bolt hole, which is the elongated hole, according to the difference in the gap between the left and right B segments, and the segment joint bolt is inserted through the bolt. By being joined, the B segment and the K segment can be joined at different positions in the radial direction of the cut-out tunnel according to the difference in the gap between the left and right B segments .

According to this aspect, at least one segment joint surface of the K segment is a first tapered surface that is inclined in the radial direction, and the height of the K segment in the radial direction is higher than that of the B segments on the left and right sides of the K segment. As a result, if the gap between the left and right B segments is too long due to construction errors, for example, the K segment enters this gap and aligns the segment joint bolt holes on the segment joint surfaces of both the B segment and the K segment. Will be possible.
Here, with respect to the fact that the first tapered surface is inclined in the radial direction, the inclined direction includes a form in which the first tapered surface is inclined in a divergent manner from the inside to the outside of the incised tunnel, and vice versa. For example, as described above, when the K segment is installed in the gap between the left and right B segments by dropping the K segment downward from the upper pipe roof side, the former form is applied.

In addition, another aspect of the segment set including the B segment and the K segment according to the present invention is characterized in that both the left and right segment joint surfaces in the K segment are the first tapered surfaces.
According to this aspect, since the left and right segment joint surfaces in the K segment are both first tapered surfaces (thus, the left and right B segments both have tapered surfaces corresponding to the K segment), the left and right B segments Since the left and right first tapered surfaces of the K segment can be locked to the tapered surface, it is possible to efficiently install the K segment even if there is a construction error.

Further, in another aspect of the segment set composed of the B segment and the K segment according to the present invention, a first seal groove in which the first seal material is housed is provided on the segment joint surface of the K segment.
It is characterized in that the length of the first seal groove in the radial direction is longer than that of the second seal groove provided on the segment joint surface of the B segment in which the second seal material is accommodated.
According to this aspect, since the K segment has a first seal groove having a length in the radial direction longer than the second seal groove of the B segment, the second seal groove is contained in the first seal groove. It becomes possible to store a sealing material that is longer in the radial direction than the sealing material housed inside. Therefore, even if there is the above-mentioned construction error, the first seal groove on the segment joint surface of the K segment is compared with the second seal material housed in the second seal groove on the segment joint surface of the B segment. The first sealing material contained therein can be reliably brought into contact with each other, and a sealing structure can be formed.

Further, one aspect of the segment set including the B segment and the K segment according to the present invention is
A B segment comprising a second tapered surface that abuts the first tapered surface of the K segment.
A segment joint bolt hole for connecting to the K segment is provided on the second tapered surface.
The segment joint bolt hole is an elongated hole that is long in the radial direction of the B segment.
According to this aspect, when the segment joint bolt hole formed on the second tapered surface of the B segment is a long hole that is long in the radial direction, there is a construction error in the circumferential direction as described above. Also, it is possible to align with the segment joint bolt holes provided on the segment joint surface of the K segment, and the bolts can be reliably inserted into both segment joint bolt holes for bolt joint.

Moreover, one aspect of the incision tunnel according to the present invention is
Said K segments constituting the segment set, with respect to the first tapered surface of the left and right of the K segment, said second tapered surface of two of said B segment constituting the segment set is in contact with cut open It ’s a tunnel,
The second segment joint bolt hole formed in the first tapered surface and the first segment joint bolt hole which is the elongated hole formed in the second tapered surface communicate with each other, and the segment joint bolt is inserted. And bolted together
The second sealing material is housed in the second sealing groove, and the first sealing material having a length longer in the radial direction than the second sealing material is housed in the first sealing groove. The first sealing material is in contact with each other to form a sealing structure.
According to this aspect, the K segment and the two second tapered surfaces of the B segment are in contact with the left and right first tapered surfaces of the K segment, so that the construction is performed in the circumferential direction as described above. Even if there is an error, it is possible to align with the segment joint bolt holes provided on the segment joint surface of the K segment, and the segment joint bolts are securely inserted into both segment joint bolt holes for bolt joint. A cut-out tunnel is formed. Further, as described above, the second seal material is housed in the second seal groove, and the first seal material having a longer radial length than the second seal material is housed in the first seal groove. Even if there is a construction error in the circumferential direction, an open tunnel having a sealing structure in which the second sealing material and the first sealing material are in contact with each other is formed.

Further, another aspect of the cut-out tunnel according to the present invention is characterized in that a filling material is provided in a gap formed when the bolt is inserted into the elongated hole.
According to this aspect, by providing a filling material in the gap formed when the segment joint bolt is inserted into the elongated hole, the displacement of the segment joint bolt in the gap of the elongated hole is eliminated. Can be done. Here, examples of the filling material include fillers such as steel rods, steel wires, reinforcing bars, and non-shrink mortar.

Moreover, one aspect of the construction method of the open tunnel according to the present invention is
This is a method of constructing an open tunnel, in which two tunnels are installed side by side and then an open tunnel connecting the two tunnels is constructed.
The B segment installation process, in which the B segment is installed on each of the two tunnels,
It has a K segment installation step of inserting and installing the K segment in the radial direction between both B segments.
Both the left and right segment joint surfaces in the K segment are first tapered surfaces that are inclined in the radial direction.
The segment joint surface in contact with the first tapered surface in the B segment is the second tapered surface inclined in the radial direction.
In the circumferential direction of the cut-out tunnel, the height of the K segment in the radial direction is higher than that of the B segment on the left and right of the K segment.
On the second tapered surface, the segment joint bolt hole connected to the K segment is a long hole that is long in the radial direction of the B segment.
In the K segment installation step, the segment joint bolt hole formed in the first tapered surface and the elongated hole opened in the second tapered surface are communicated with each other, and the segment joint bolt is inserted and bolted. It is characterized by that.
According to this aspect, even if there is a construction error in the circumferential direction, it is possible to align the corresponding segment joint bolt holes provided on the segment joint surfaces of both the K segment and the B segment, and both of them can be aligned. It is possible to construct a cut-out tunnel in which the segment joint bolt is securely inserted into the segment joint bolt hole and bolted. Further, as described above, the second seal material is housed in the second seal groove, and the first seal material having a longer radial length than the second seal material is housed in the first seal groove. When the segment joint surfaces of both the K segment and the B segment are brought into contact with each other by dropping the segment or the like, the second sealing material and the first sealing material are brought into contact with each other, and the sealing structure can be reliably formed.

According to the segment set consisting of the B segment and the K segment of the present invention, the open tunnel and the construction method thereof, in the construction of the open tunnel connecting the two tunnels arranged side by side, there is a construction error in the circumferential direction. Finally, a K segment can be installed to construct an open tunnel.

It is a vertical cross-sectional view explaining the construction method and the temporary structure of the merging part of a road tunnel. It is a vertical cross-sectional view explaining the construction method and the main structure of the merging part of a road tunnel. It is a front view as seen from the main girder side as an example of the K segment which constitutes the segment set which concerns on embodiment. FIG. 3 is an arrow view in the IV direction of FIG. 3, which is a side view of an example of the K segment constituting the segment set according to the embodiment as viewed from the segment joint side. It is a front view as seen from the main girder side as an example of the B segment which constitutes the segment set which concerns on embodiment. FIG. 5 is a view taken in the direction of arrow VI, which is a side view of an example of the B segment constituting the segment set according to the embodiment as viewed from the segment joint side, which is a tapered surface inclined with respect to the axial center in the circumferential direction. .. It is a VII direction arrow view of FIG. 5, and is a side view of an example of the B segment constituting the segment set according to the embodiment as viewed from the segment joint side perpendicular to the axial center in the circumferential direction. A vertical cross-sectional view illustrating a part of an example of the open tunnel according to the embodiment, which is formed by dropping the K segments constituting the segment set according to the embodiment into a gap having no construction error in the circumferential direction of the open tunnel. Is. A vertical cross section for explaining a part of an example of the cut-out tunnel according to the embodiment, which is formed by dropping the K segment constituting the segment set according to the embodiment into a gap having a large construction error in the circumferential direction of the cut-off tunnel. It is a figure. A vertical cross section for explaining a part of an example of the cut-out tunnel according to the embodiment, which is formed by dropping the K segment constituting the segment set according to the embodiment into a gap having a small construction error in the circumferential direction of the cut-off tunnel. It is a figure.

Hereinafter, the K segment and the B segment constituting the segment set according to each embodiment, the incision tunnel, and the construction method thereof will be described with reference to the attached drawings. In the present specification and the drawings, substantially the same components may be designated by the same reference numerals to omit duplicate explanations.

[K segment constituting the segment set according to the embodiment]
First, an example of the K segment constituting the segment set according to the embodiment will be described with reference to FIGS. 3, 4 and 8. Here, FIG. 3 is a front view of an example of the K segment constituting the segment set according to the embodiment as viewed from the main girder side, and FIG. 4 is an arrow view in the IV direction of FIG. 3, which is an embodiment. It is a side view seen from the segment joint side as an example of the K segment which constitutes the segment set which concerns on. Further, FIG. 8 is a part of an example of the open tunnel according to the embodiment, which is formed by dropping the K segment constituting the segment set according to the embodiment into a gap having no construction error in the circumferential direction of the open tunnel. It is a vertical sectional view explaining. Here, in explaining the K segment constituting the segment set according to the embodiment, it is easy to understand the characteristic configuration of the K segment by referring to an example of the open tunnel according to the embodiment. It will be referred to as appropriate.

As shown in FIG. 8, the K segment 20D is opened in the gap between the left and right B segments 20B arranged in the circumferential direction in the open tunnel 700A connecting the two parallel tunnels 100 and 200. It is a segment that is dropped (or inserted) in the radial direction of the tunnel 700A.

As shown in FIGS. 3 and 8, the K segment 20D includes two steel main girders 25 having a predetermined curvature extending in the circumferential direction and outer peripheral sides (formed segments) of the two main girders 25. A steel skin plate 26 that connects the main girders 25 to each other and extends in the circumferential direction on the outside (ground side) of the ring, and steel joint plates attached to both ends of the main girder 25 and the skin plate 26. It has 27A and 27B (an example of a segment joint surface).

The main girder 25 is provided with a plurality of ring joint bolt holes 25a on its side surface. In the K segment 20D, the ring joint bolt hole 25a is formed as an elongated hole long in the radial direction. Further, a steel vertical rib 28 having a width extending over the main girder 25 is arranged between the two main girders 25, and the vertical rib 28 enhances the rigidity of the box-shaped K segment 20D. ing.

Of the joint plates 27A and 27B, a first seal groove 27a having a length t1'long in the radial direction is formed on the outer peripheral side of the main girder 25. Further, among the joint plates 27A and 27B, a plurality of segment joint bolt holes 27b made of round holes are formed at predetermined intervals inside the main girder 25 in the radial direction with respect to the first seal groove 27a. In the illustrated example, four segment joint bolt holes 27b are provided in two rows in a row, but there are various forms in the number and rows of bolt holes. Further, the segment joint bolt hole may be an elongated hole long in the radial direction.

In the K segment 20D, both the left and right segment joint surfaces 27A and 27B are first tapered surfaces that diverge toward the outer peripheral side. The length t1 in the taper direction on the first tapered surface is longer than the length t2 in the taper direction on the second tapered surface of the B segment 20B (see FIG. 5 and the like) described in detail below. Here, as shown in FIG. 8, the K segment 20D of the illustrated example is installed in the gap between the left and right B segments 20B so as to be dropped downward in the radial direction from the upper construction space SP. As shown in FIGS. 3 and 8, it is the first tapered surface that expands toward the outer periphery, but when the K segment is inserted from the inside to the upper side in the radial direction, unlike FIG. 3, it is in the radial direction. It has a tapered surface that spreads toward the inside.

As shown in FIG. 8, the radial height of the K segment 20D is set higher than the radial height of the B segments 20B on the left and right sides of the K segment 20D. Since the radial height of the K segment 20D dropped at the end is set higher than the radial height of the adjacent B segment 20B, as will be described in detail below with reference to FIGS. 9 and 10. When dropping the K segment 20D, even if the gap between the left and right B segments 20B is too large or too small in the circumferential direction due to a construction error, the segment joint surfaces of both the B segment 20B and the K segment 20D , Both bolt holes can be aligned. Therefore, in the construction of the open tunnel 700A, even if there is a construction error in the circumferential direction at the construction stage before the installation of the K segment 20D, the B segment 20B and the K segment 20D can be bolted together with the segment joint bolt. It will be possible.

[B segment constituting the segment set according to the embodiment]
Next, an example of the B segment constituting the segment set according to the embodiment will be described with reference to FIGS. 5 to 7 and 8. Here, FIG. 5 is a front view of an example of the B segment constituting the segment set according to the embodiment as viewed from the main girder side. Further, FIG. 6 is a view taken along the line VI of FIG. 5, from the segment joint side, which is a tapered surface inclined with respect to the axial center in the circumferential direction, as an example of the B segment constituting the segment set according to the embodiment. It is a side view as seen. Further, FIG. 7 is a view taken along the line VII of FIG. 5, which is a side view of an example of the B segment constituting the segment set according to the embodiment as viewed from the segment joint side perpendicular to the axial center in the circumferential direction. Is. In the description of the B segment constituting the segment set according to the embodiment, FIG. 8 will be referred to as appropriate because it will be easy to understand.

As shown in FIG. 8, the B segment 20B is arranged on both sides of the K segment 20D which is finally dropped in the circumferential direction in the open tunnel 700A connecting the two tunnels 100 and 200 arranged side by side. It is a segment joined with the segment 20D.

As shown in FIGS. 5 and 8, the B segment 20B consists of two main girders 25A made of steel having a predetermined curvature extending in the circumferential direction and the main girders 25A on the outer peripheral side of the two main girders 25A. It has a steel skin plate 26A extending in the circumferential direction by connecting the two, and steel joint plates 27C and 27D (an example of a segment joint surface) attached to both ends of the main girder 25A and the skin plate 26A. ..

The main girder 25A is provided with a plurality of ring joint bolt holes 25b made of round holes on its side surface. Further, a plurality of steel vertical ribs 28A having a width extending over the main girders 25A are arranged between the two main girders 25A, and the plurality of vertical ribs 28A form a box-shaped B segment 20B. Rigidity is increased.

Of the joint plate 27C, a second seal groove 27c having a length t2', which is shorter in the radial direction than the first seal groove 27a of the K segment 20D, is formed on the outer peripheral side of the main girder 25A. .. Further, in the joint plate 27C, a plurality of segment joint bolt holes 27d made of elongated holes are formed at predetermined intervals inside the main girder 25A with respect to the second seal groove 27c. In the illustrated example, eight segment joint bolt holes 27d are similarly provided at positions corresponding to the eight segment joint bolt holes 27b of the K segment 20D shown in FIG.

On the other hand, of the joint plate 27D, a second seal groove 27c having a length t2', which has a short radial length like the joint plate 27C, is formed on the outer peripheral side of the main girder 25A. Further, in the joint plate 27D, a plurality of segment joint bolt holes 27e made of round holes are formed at predetermined intervals inside the main girder 25A with respect to the second seal groove 27c.

In the B segment 20B, the segment joint surface 27C connected to the K segment 20D has a second tapered surface 27C that abuts on the first tapered surfaces 27A and 27B of the K segment 20D. Then, as shown in FIGS. 5 and 6, the length t2 of the second tapered surface 27C along the taper direction is set shorter than the length t1 of the first tapered surfaces 27A and 27B of the K segment 20D along the taper direction. Has been done.

On the other hand, in the B segment 20B, for example, as shown in FIG. 8, the joint plate 27D connected to the joint plate 27E of the A segment 20A has a vertical plane orthogonal to the axial axis in the circumferential direction. As shown in FIG. 7, the length of the joint plate 27 (the radial height of the B segment 20B) is t3.

[Cut tunnel and its construction method according to the embodiment]
Next, an example of the cut-out tunnel and its construction method according to the embodiment will be described with reference to FIGS. 8 to 10. Here, FIG. 8 is an example of an open tunnel according to an embodiment, in which K segments constituting the segment set according to the embodiment are dropped into a gap having no construction error in the circumferential direction of the open tunnel. It is a vertical sectional view explaining a part. Further, FIG. 9 is an example of the open tunnel according to the embodiment, in which the K segment constituting the segment set according to the embodiment is dropped into a gap having a large construction error in the circumferential direction of the open tunnel. It is a vertical sectional view explaining a part. Further, FIG. 10 is an example of the open tunnel according to the embodiment, in which the K segment constituting the segment set according to the embodiment is dropped into a gap having a small construction error in the circumferential direction of the open tunnel. It is a vertical sectional view explaining a part.

In the open tunnel 700A shown in FIG. 8, the A segment 20A and the B segment 20B are constructed in the circumferential direction of the open tunnel 700A in a manner without construction error, and the K segment 20D is provided in the gap between the left and right B segments 20B without any error. By being dropped, an open tunnel 700A is formed.

As shown in FIG. 1, the cut-out tunnel 700A is opened by constructing two tunnels 100 and 200 such as a ramp tunnel 100 and a main line tunnel 200, and then digging a watermark directly under the pipe roof 300 to form a construction space SP. Various segments for the tunnel 700 are sequentially installed while being transported from the tunnel 100 side and the tunnel 200 side, respectively. More specifically, as shown in FIG. 2, the A segment 20A is installed on the tunnel 100, 200 side (in the example shown in FIG. 2, the tunnel 100 side), and further, the B segment is installed inside the A segment 20A in the circumferential direction. Along with installing 20B, a B segment is also installed on the tunnel 200 side (B segment installation process). The number of A segments 20A to be installed is not limited, and a plurality of A segments 20A may be installed, but at least B segments 20B must be installed on the left and right sides of the K segment 20D.

In this B segment installation step, as shown in FIG. 8, a gap for installing the K segment 20D is provided between the left and right B segments 20B. In the example shown in FIG. 8, this gap is formed in such a manner that there is no construction error. Next, the K segment 20D is installed in the construction space by transporting the K segment 20D and dropping the K segment 20D downward in the radial direction into the gap between the B segments 20B without construction error (K segment installation process). ..

In the state shown in FIG. 8, the segment joint bolt holes 27b provided in the segment joint surfaces 27A and 27B, which are the first tapered surfaces of the K segment 20D, are the segment joint surfaces, which are the second tapered surfaces of the B segment 20B. It is aligned with the segment joint bolt holes 27d (long holes) provided in 27C, and the segment joint bolts 95 are inserted into the corresponding segment joint bolt holes 27b and 27d and bolted together.

Further, in the state shown in FIG. 8, the first seal material 91 housed in the first seal groove 27a provided on the segment joint surfaces 27A and 27B and the second seal groove provided on the segment joint surface 27C. The first sealing material 92 contained in 27c is brought into contact with each other in a compressed manner to form a sealing structure.

Since the segment joint bolt hole 27d is a long hole in the state where the segment joint bolt 95 is inserted into the corresponding segment joint bolt holes 27b and 27d, in the state of the illustrated example without construction error, for example, the long hole 27d A segment joint bolt 95 is inserted at the center position, and there are gaps on both sides thereof. Therefore, by providing the filling material 96 in this gap, it is possible to eliminate the deviation of the segment joint bolt 95 in the gap of the elongated hole 27d. Here, examples of the filling material 96 include fillers such as steel rods, steel wires, reinforcing bars, and non-shrink mortar.

As shown in FIG. 8, the circumferential structure of the cut tunnel 700A is formed, and the plurality of the circumferential structures are bolted to each other on the ring joint surface to form the cut tunnel 700A having a predetermined extension. .. More specifically, a ring joint bolt (not shown) is inserted into the corresponding ring joint bolt hole 25b between the B segments 20B adjacent to each other in the extension direction of the incision tunnel 700A, and the corresponding ring between the K segments 20D is similarly inserted. Ring joint bolts (not shown) are inserted into the joint bolt holes 25a and bolted together. Here, since the ring joint bolt hole 25a possessed by the K segment 20D is a long hole that is long in the radial direction, even if there is a construction error between adjacent K segments 20D, bolt joining with the ring joint bolt is possible. become.

On the other hand, in FIG. 9, A segment 20A and B segment 20B are constructed in a mode with a large construction error in the circumferential direction of the incision tunnel 700A, and K is formed in the gap between the left and right B segments 20B with a large error. By dropping the segment 20D, an open tunnel 700A is formed.

In the cut-out tunnel 700A shown in FIG. 9, since the gap in the circumferential direction is too large, the K segment 20D is installed so as to be depressed inward in the radial direction as compared with the case where there is no error shown in FIG. However, since the height of the K segment 20D in the radial direction is higher than that of the B segment 20B, the skin plate 26 of the K segment 20D has a mode or surface protruding outward from the skin plates 26A of the left and right B segments 20B. In one embodiment, the left and right first tapered surfaces 27A and 27B of the K segment 20D are locked to the second tapered surfaces 27C of the left and right B segments 20B (in the example shown in FIG. 9, the skin plate 26 is slightly (Protruding outward).

Then, in the state shown in FIG. 9, the first seal groove 27a of the K segment 20D and the second seal groove 27a contained therein are accommodated with respect to the second seal groove 27c of the B segment 20B and the second seal material 92 accommodated therein. Since the first sealing material 91 is long in the radial direction, the first sealing material 91 and the second sealing material 92 can be brought into contact with each other in a compressed manner, as in the state shown in FIG. A seal structure can be formed. Specifically, as shown in FIG. 9, the upper portion of the first sealing material 91 and the second sealing material 92 come into contact with each other to form a sealing structure.

Further, since the segment joint bolt holes 27d formed on the segment joint surface 27C of the B segment 20B are elongated in the radial direction, the segment joint bolt holes 27d and the segment joint surfaces 27A and 27B of the K segment 20D are further formed. The segment joint bolt holes 27b provided in the above can be aligned, and the segment joint bolts 95 can be inserted into the corresponding segment joint bolt holes 27b and 27d to be bolted. In the cut-out tunnel 700A shown in FIG. 9, a gap is formed above the segment joint bolt hole 27d, which is a long hole, and therefore, a filling material 96 is provided in this gap.

In this way, even if there is a large construction error in the circumferential direction at the construction stage before the installation of the K segment 20D, by applying the B segment 20B and the K segment 20D, the B segment 20B and the K segment 20D can be applied. It is guaranteed that the first sealing material 91 and the second sealing material 92 form a sealing structure on the segment joint surface of the above, and the bolt joint by the segment joint bolt is guaranteed.

In contrast to FIG. 9, FIG. 10 shows that the A segment 20A and the B segment 20B are constructed in the circumferential direction of the incision tunnel 700A in a mode with a small construction error, and in the gap between the left and right B segments 20B with a small error. By dropping the K segment 20D, an open tunnel 700A is formed.

In the cut-out tunnel 700A shown in FIG. 10, since the gap in the circumferential direction is too small, the K segment 20D is installed so as to project outward in the radial direction as compared with the case where there is no error shown in FIG. However, since the height of the K segment 20D in the radial direction is higher than that of the B segment 20B, the lower end of the K segment 20D protrudes inward from the lower ends of the left and right B segments 20B, or is flush with each other. , The left and right first tapered surfaces 27A and 27B of the K segment 20D are locked to the second tapered surfaces 27C of the left and right B segments 20B (in the example shown in FIG. 10, the lower end of the K segment 20D is slightly inward. (Protruding).

Then, in the state shown in FIG. 10, the first seal groove 27a of the K segment 20D and the second seal groove 27a contained therein are accommodated with respect to the second seal groove 27c of the B segment 20B and the second seal material 92 accommodated therein. Since the first sealing material 91 is long in the radial direction, the first sealing material 91 and the second sealing material 92 can be brought into contact with each other in a compressed manner, as in the state shown in FIG. A seal structure can be formed. Specifically, as shown in FIG. 10, the lower portion of the first sealing material 91 and the second sealing material 92 come into contact with each other to form a sealing structure.

Further, since the segment joint bolt holes 27d formed on the segment joint surface 27C of the B segment 20B are elongated in the radial direction, the segment joint bolt holes 27d and the segment joint surfaces 27A and 27B of the K segment 20D are further formed. The segment joint bolt holes 27b provided in the above can be aligned, and the segment joint bolts 95 can be inserted into the corresponding segment joint bolt holes 27b and 27d to be bolted. In the cut-out tunnel 700A shown in FIG. 10, a gap is formed below the segment joint bolt hole 27d, which is a long hole, and therefore, a filling material 96 is provided in this gap.

In this way, even if there is a small construction error in the circumferential direction at the construction stage before the installation of the K segment 20D, by applying the B segment 20B and the K segment 20D, the B segment 20B and the K segment 20D can be applied. It is guaranteed that the first sealing material 91 and the second sealing material 92 form a sealing structure on the segment joint surface of the above, and the bolt joint by the segment joint bolt is guaranteed.

It should be noted that the configuration or the like described in the above embodiment may be another embodiment in which other components are combined, and the present invention is not limited to the configuration shown here. This point can be changed without departing from the spirit of the present invention, and can be appropriately determined according to the application form thereof.

20: Segment 20A: A segment 20B: B segment 20C, 20D: K segment 25, 25A: Main girder 25a: Ring joint bolt hole 26, 26A: Skin plate 27A, 27B: Joint plate (segment joint surface, first tapered surface) )
27C: Joint plate (segment joint surface, second taper surface)
27D, 27E: Joint plate (segment joint surface)
27a: First seal groove 27b: Segment joint bolt hole 27c: Second seal groove 27d: Segment joint bolt hole (long hole)
27e, 27f: Segment joint bolt holes 28, 28A: Vertical rib 91: First seal material 92: Second seal material 95: Segment joint bolt 96: Filling material 100: Lamp tunnel (tunnel)
200: Main line tunnel (tunnel)
300,300A: Pipe roof 700,700A: Open tunnel

Claims (6)

Cut open constitutes a tunnel connecting the two tunnels juxtaposed, with each tunnel and B segments are arranged in side and a K segments disposed is inserted into the gap between the left and right of the B segment, B A segment set consisting of segments and K segments
At least one segment joint surface of the K segment is a first tapered surface that is inclined in the radial direction.
In the B segment, the segment joint surface that comes into contact with the first tapered surface of the K segment is a second tapered surface that is inclined in the radial direction.
In the circumferential direction of the cut open tunnel, the height of the radial direction of the K segment rather higher than the B segment on the left and right of the K segments,
The first segment joint bolt hole connected to the K segment, which is provided on the second tapered surface, is an elongated hole long in the radial direction of the B segment.
A second segment joint bolt hole for connecting to the B segment is provided on the first tapered surface.
The second segment joint bolt hole is positioned at a different position of the first segment joint bolt hole, which is a long hole, and the segment joint bolt is inserted according to the difference in the gap between the left and right B segments. By being bolted, the B segment and the K segment can be freely joined at different positions in the radial direction of the cut tunnel according to the difference in the gap between the left and right B segments. , A segment set consisting of B segment and K segment . The segment set comprising the B segment and the K segment according to claim 1, wherein both the left and right segment joint surfaces in the K segment are the first tapered surfaces. A first seal groove for accommodating the first seal material is provided on the segment joint surface of the K segment.
1 or claim 1, wherein the length of the first seal groove in the radial direction is longer than that of the second seal groove provided on the segment joint surface of the B segment in which the second seal material is accommodated. A segment set consisting of the B segment and the K segment according to 2. Said K segments constituting the segment set according to claim 3, with respect to the first tapered surface of the left and right of the K segments, two of the B segments constituting the segment set according to claim 3 A cut-out tunnel to which the second tapered surface is in contact.
The second segment joint bolt hole formed in the first tapered surface and the first segment joint bolt hole which is the elongated hole formed in the second tapered surface communicate with each other, and the segment joint bolt is inserted. And bolted together
The second sealing material is housed in the second sealing groove, and the first sealing material having a length longer in the radial direction than the second sealing material is housed in the first sealing groove. A cut-out tunnel characterized in that the first sealing material is in contact with each other to form a sealing structure. The cut-out tunnel according to claim 4 , wherein a filling material is provided in a gap formed when the segment joint bolt is inserted into the elongated hole. This is a method of constructing an open tunnel, in which two tunnels are installed side by side and then an open tunnel connecting the two tunnels is constructed.
The B segment installation process, in which the B segment is installed on each of the two tunnels,
It has a K segment installation step of inserting and installing the K segment in the radial direction between both B segments.
Both the left and right segment joint surfaces in the K segment are first tapered surfaces that are inclined in the radial direction.
The segment joint surface in contact with the first tapered surface in the B segment is the second tapered surface inclined in the radial direction.
In the circumferential direction of the cut-out tunnel, the height of the K segment in the radial direction is higher than that of the B segment on the left and right of the K segment.
On the second tapered surface, the segment joint bolt hole connected to the K segment is a long hole that is long in the radial direction of the B segment.
In the K segment installation step, the segment joint bolt hole formed on the first tapered surface and the elongated hole provided on the second tapered surface are communicated with each other, and the segment joint bolt is inserted and bolted. A method of constructing an open tunnel, which is characterized by the fact that.

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