JP2008075386A - Spectacle shield tunnel structure and method of constructing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spectacle shield tunnel structure and a method of constructing it capable of reducing installation cost for stiffening members and shortening construction period by minimizing the strength required for the stiffening members when both tunnels are cut and allowed to communicate with each other by installing, at the communication joint part of the shield tunnels, the stiffening members for stiffening the segments of both shield tunnels by joining them to each other for stabilizing the structure. <P>SOLUTION: In this spectacle shield tunnel structure and the method of constructing it, the side parts of shield tunnels 2, 4 of circular shape in cross section arranged in proximity to and parallel to each other are cut and communicably joined to each other. A stiffening member 6 for stiffening both shield tunnels by joining the segments 12 thereof to each other is installed over and under the communication part 23. A segment 12a disposed at each of the sides of both tunnels facing the communication part 23 is formed to have a rigidity higher than that of the segments 12 disposed at the other portions. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a structure of a glasses-type shield tunnel formed by cutting out side portions of a plurality of shield tunnels having a circular cross-section that are arranged in close proximity to each other and integrally communicating with each other, and a method for constructing the same. .

  The shield method is generally adopted as a tunnel construction method for ground where there is groundwater or soft ground, such as in civil engineering, for example, and a lining body covering the inner surface of the tunnel excavation is provided behind the shield machine. The segments are sequentially assembled and formed into a ring shape by the segments, and the shield excavator is moved forward while performing the excavation work while obtaining the propulsive reaction force from the formed lining body.

  By the way, when constructing an underground structure using such a shield construction method, for example, in the construction of a subway station or a branch / junction of an underground road, a plurality of shield tunnels are arranged side by side in parallel. The side portions of the shield tunnel are connected to each other and connected to each other, and the cross section thereof is integrated with a composite tunnel such as glasses. Here, in the tunnel having such a cross-sectional shape, the rigidity of the communication coupling portion is reduced in shape, so that, for example, as shown in Japanese Patent No. 2619937, the communication coupling portion includes a number of supporting columns. A rigid member is provided to compensate for the rigidity.

  However, if a post is provided as described above to ensure the strength of the connecting and connecting part of the shield tunnel, for example, at the branching / merging part of the road, the post is obstructed and the vehicle smoothly enters the tunnel. Will not be able to make any traffic. In particular, in order to perform safe and smooth branching / merging on an expressway, a column-free section is required over a predetermined length. Therefore, when constructing such a branching / merging section, either use a shield tunnel structure with a large circular section so that the main road and the branching / merging road can be installed in one shield tunnel, or from the ground. The only way to install the branching / merging section was on the ground, either by adopting a large-section rectangular structure by the open-cut method or by changing the alignment of the road itself.

  Therefore, the present applicant has advanced the development of a tunnel and a construction method thereof that can secure a wide space without a support, and has made a proposal as disclosed in Japanese Patent Laid-Open No. 2003-138899.

That is, in the technique disclosed in the publication, when the shield tunnels arranged adjacent to each other are indirectly connected to each other via the coupling portion, the upper plate portion and the lower plate portion are parallel to the coupling portion in the vertical direction. And an underground beam is provided above the coupling portion. The underground beam includes a starter, a reacher, and an arch, and the arch is formed in a semicircular shape that forms a hollow cylinder and circulates around the outer periphery of the upper part of the tunnel. Are integrated with each other. A plurality of suspension anchors are installed between the coupling portion and the underground beam. The suspension anchor is fixedly fixed to a fixing block provided at the upper end of the coupling portion at the lower end side, and the upper end side of each suspension anchor is fixedly fixed to the side wall of the hollow tube body of the arch portion.
Japanese Patent No. 2619937 JP 2003-138899 A

  However, in the above-mentioned proposal, a support structure including a large underground beam for supporting the coupling portion, its starting portion, a reaching portion, and the like is disposed outside the parallel shield tunnel. Therefore, the construction also becomes very large, extending from both outer sides of the shield tunnel to the upper part, and there is still room for improvement in terms of construction cost, construction period, exclusive area, etc. there were.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a stiffening member such as an underground beam for stiffening by connecting the segments of both shield tunnels to each other at the connecting and connecting portions of the shield tunnels. Therefore, the required strength of the stiffening member can be reduced as much as possible when stabilizing the structure and excavating both tunnels, thus reducing the installation cost of the stiffening member and shortening the construction period. It is to provide an eyeglass-type shield tunnel structure that can be realized and a construction method thereof.

  In order to achieve the above object, the glasses-type shield tunnel structure according to the present invention is a glasses-type shield tunnel in which side portions of a plurality of shield tunnels having a circular cross section arranged in close proximity are cut and connected to each other. A stiffening member is provided above and below the communicating portion to be connected and connected to stiffen the segments of both shield tunnels, and the side portions of both tunnels facing the communicating portion are provided. The disposed segments are configured to have a higher rigidity than segments disposed in other portions.

  Alternatively, in the glasses-type shield tunnel structure in which the side portions of the shield tunnels having a plurality of circular cross-sections arranged in close proximity are cut and formed in communication connection, and above and below the communication portions formed in communication connection A stiffening member is provided for stiffening the segments of both shield tunnels by connecting them, and the side portions of both tunnels facing the communicating portion are provided with the rigidity of the segments disposed on the side portions, The present invention is characterized in that a stiffening means that is higher than the segment of the part is provided.

  Here, a column may be adopted as the stiffening means. Alternatively, the segments of the two shield tunnels are made of steel, and the stiffening means is made of concrete filled in the segments disposed in the side portions of the two shield tunnels facing the communication portion. obtain.

  Further, in order to achieve the above object, the construction method of the glasses-type shield tunnel according to the present invention is such that the side portions of the shield tunnels having a plurality of circular cross-sections arranged close to each other are cut and connected to each other. A method for constructing a glasses-type shield tunnel, in which a segment disposed in a side portion of both shield tunnels facing a portion where the communication portion is to be formed is preliminarily more rigid than a segment of another portion. Both shield tunnels are formed and stiffened by providing stiffening members that connect the segments of both shield tunnels above and below the site where the communication portion to be connected and connected is to be formed, and then the communication portion is cut and formed. It is characterized by the configuration.

  Alternatively, a method for constructing a glasses-type shield tunnel in which side portions of a plurality of shield tunnels having a circular cross-section that are arranged in parallel are cut and formed in communication connection, and the formation part of the communication part to be connected and connected A stiffening member that connects between the segments of both shield tunnels is provided above and below to stiffen, and the segments of the side portions of both shield tunnels facing the portion where the communication portion is to be formed are separated by other stiffening means. A feature is that the communicating portion is cut and formed after being stiffened to a higher rigidity than the segment of the part.

  Alternatively, a method for constructing a glasses-type shield tunnel in which side portions of a plurality of shield tunnels having a circular cross-section arranged in close proximity are cut and formed to communicate with each other, and the connection-communication planned site between the shield tunnels An arc-shaped steel curved pipe is bridged from one side of the shield tunnel to the other side of the ground in both sides of the shield tunnel using a curved boring device, and a predetermined number of pitches at a predetermined pitch along the tunnel longitudinal direction. A steel bent pipe installation step to be installed, and a segment stiffening step of stiffening the segments of the side portions of both shield tunnels facing the planned connection and connection portions with higher rigidity than the segments of other portions by stiffening means And after the end of the steel bent pipe installation step and the segment stiffening step, the two shield tunnels are cut into segments at the communication joint portion planned portions, A configuration comprising a shield tunnel communication step of excavating and communicating a ground between the tunnels, and a connection member installation step of installing a connection member across the edges of the segment rings opened in both shield tunnels; It is characterized by what has been done.

  Moreover, it became the structure provided with the concrete filling process of filling concrete into the space | gap between the said connection member and the said steel curved pipe after the said connection member installation process.

  Further, an internal support installation step for installing an internal support for preventing deformation of the tunnel, which is constructed before the shield tunnel communication step, and for preventing deformation of the tunnel, and the connecting member and the steel bent pipe The present invention is characterized in that it comprises a support work removing step of removing the internal support work after the concrete filled in the space between them is hardened.

  In addition, a configuration including a ground improvement process for injecting a chemical solution into a natural ground from a chemical solution injection port formed in a segment of the shield tunnel between the steel bent pipe installation step and the shield tunnel communication step. It is characterized by that.

  Also, between the steel bent pipe installation step and the shield tunnel communication step, a ground improvement step for improving the ground by injecting a chemical into the surrounding natural ground through the steel bent pipe was adopted. It is characterized by.

  Further, in the steel bent pipe installation step, a steel bent pipe for maintaining rigidity and a steel bent pipe for injecting chemical liquid are separately provided, and the bent steel pipe for injecting chemical liquid is made of the steel for holding rigidity. It is characterized in that the position is shifted and arranged outside the curved pipes.

  Further, the stiffening means in the segment stiffening step is constituted by a column.

  The segments of both shield tunnels are steel segments, and the stiffening means in the segment stiffening step fills the inside of the segments disposed in the side portions of both shield tunnels facing the communicating portion. It is characterized by the construction made of concrete. Here, the strut may be used in combination as a stiffening means.

  Further, the rigid holding steel bent pipe has a double pipe structure including an inner pipe and an outer pipe.

  Further, the present invention is characterized in that an H-shaped steel is inserted and disposed in the rigid bent steel pipe.

  In addition, concrete is filled in the rigid steel holding bent tube.

  Further, a steel wire to which tension is applied is arranged in the steel bent pipe for maintaining rigidity in order to introduce prestress into the steel bent pipe.

  According to the glasses-type shield tunnel structure and its construction method of the present invention as described above, a stiffening member for stiffening by connecting the segments of both shield tunnels to each other in the communication coupling portion of the shield tunnels is provided. When the two shield tunnels are opened and communicated by stabilizing the structure, the segments disposed on the side portions of both shield tunnels facing the communicating portion have higher rigidity than the segments disposed on other portions. Since it is stiffened, it is possible to reduce the flexural deformation of the part to be opened and communicated as much as possible, and to reduce the required yield strength of the stiffening member as much as possible. For this reason, the number of installation of the stiffening member can be reduced, or the rigidity of the stiffening member itself can be set low, so that the installation cost can be reduced and the construction period can be shortened.

  Hereinafter, preferred embodiments of a glasses-type shield tunnel structure and a construction method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

  First, the fundamental concept of the eyeglass-type shield tunnel structure and the construction method thereof according to the present invention will be described. The side portions of a plurality of shield tunnels having a circular cross section arranged in parallel are cut and connected to each other. By forming, when constructing a glasses-type shield tunnel, a stiffening member for connecting and stiffening the segments of both shield tunnels is provided above and below the communication portion to be connected and formed. The segments disposed in the side portions of the opposing shield tunnels are formed with higher rigidity than the segments disposed in other portions.

  That is, when the segment of the communication formation part is removed and opened by removing the segment of the communication formation part by increasing the rigidity of the segment disposed in the side part of both shield tunnels facing the communication part. The bending deformation generated in the cut-off side portion of the subsequent shield tunnel is suppressed as small as possible, and the proof stress required for the stiffening member is reduced as much as possible. As a result, the number of the stiffening members can be reduced, or the rigidity of the stiffening member itself can be set low.

As a means for increasing the rigidity of the segments disposed in the side portions of both shield tunnels facing the communicating portion, a highly rigid one may be installed in advance in the segment of the part at the time of assembling the segment, Initially, the same segment may be assembled over the entire circumference, and at the stage before excavation, stiffening means for increasing the rigidity of the segment at the above site may be provided later to improve the rigidity.
Next, specific embodiments will be described with reference to the accompanying drawings.

<< First Embodiment >>
FIGS. 1-8 is the schematic which shows each construction process of the construction method of the spectacles type shield tunnel in 1st Embodiment in order, and is applied to construction of the branch and merge part of an underground highway in this Embodiment. The case is illustrated.

  As shown in FIG. 1, a road for a branch / merging portion is provided close to the side of the first shield tunnel 2 having a large circular cross section for providing a main road and the first shield tunnel 2 for the main road. The second shield tunnels 4 having a small circular cross section for providing are juxtaposed. The shield tunnels 2 and 4 are adjacently arranged so that the tunnel axes are parallel to each other. Further, a steel body 12 having the same standard is annularly assembled on the inner peripheral surface of each shield tunnel 2, 4 to form a covering body 10.

  In addition, the shield tunnels 2 and 4 having two circular cross-sections arranged in close proximity to each other in this manner are formed by opening and connecting the adjacent side portions to form a two-way road tunnel. It will be. The circular cross section of the shield tunnel is not limited to the perfect circular shape shown in the figure, and may be elliptical.

  FIG. 2 shows a steel bent pipe installation process. As shown in the figure, in this steel bent pipe installation process, from one side of shield tunnels 2 and 4 to the other, in the ground 8 on both the upper and lower sides of the site where the connection between both shield tunnels 2 and 4 is planned, An arcuate steel curved pipe 6 is stretched using a curved boring device as a stiffening member. Here, with the first shield tunnel 2 side as the starting portion and the second shield tunnel 4 side as the reaching portion, the steel bent pipe 6 is sequentially pushed into the ground 8 by the propulsion method and passed. A predetermined number of these steel bent pipes 6 are installed at a predetermined pitch along the longitudinal direction of the tunnel.

  Specifically, as shown in FIG. 9, in this embodiment, three steel curved pipes 6 are provided for each segment 1 ring. That is, six segments 12 forming the lining body 10 of each shield tunnel 2 and 4 form one turn. In each of the shield tunnels 2 and 4, the segment 12 where the steel bent pipe 6 is spanned is provided with a receiving portion of the steel bent tube 6 closed in advance by a removable cover, and the receiving portion Is opened and the steel bent pipe 6 is installed. The segments 12 are made of steel plate or steel plate concrete having a width of 1.2 m, and reinforcing ribs 14 are erected at intervals of 40 cm, and the steel bent pipes 6 are provided at a pitch of 40 cm between the reinforcing ribs 14. Yes. The diameter of the steel bent pipe is 30 cm.

  Further, in the first embodiment, the steel bent tube 6 is provided exclusively for maintaining rigidity, and a chemical solution for ground improvement is injected into the surrounding natural ground 8 outside the steel bent tube 6. A steel bent tube 16 is provided in the same manner. This chemical solution injection steel bent tube 16 has a large number of chemical solution injection ports (not shown) on its pipe surface, and is positioned substantially in the middle of the steel bent tubes 6 and 6 for maintaining rigidity. The pitches are arranged so as to be shifted from each other, so that the chemicals injected into the natural ground 8 are easily transmitted to the natural ground in the inner part sandwiched between the upper and lower rigid steel bending pipes 6. . The diameter of the steel pipe 16 for injecting a chemical solution is 10 to 15 cm, which is narrower than that of the steel pipe 6 for maintaining rigidity.

  FIG. 3 shows a ground improvement process, in which the chemical solution is injected into the ground improvement region 18 in the surrounding natural ground 8 through the steel bending pipe 16 for chemical solution injection, and the ground improvement is performed. In addition, the steel bending tube 6 for maintaining the rigidity may be provided with a chemical injection function, and the steel bending tube 16 for chemical injection may be omitted. Furthermore, the injection of the chemical solution may be performed from the chemical solution injection port formed in advance in the segment 12 of the lining body 10 instead of the rigid bending steel bent pipe 6 to improve the ground.

  When the ground improvement is completed, as shown in the segment stiffening step of FIG. 4, the segments 12a of the side portions of the shield tunnels 2 and 4 facing the communication joint planned portion are made to be segmented by the stiffening means. It stiffens to a higher rigidity. Here, a column 21 made of H-shaped steel or the like is provided as a stiffening means. The support column 21 is provided close to the segment 12a of the side portion of the shield tunnels 2 and 4 facing the communication connection planned site, and each support column 21 has its upper end portion and lower end portion integrated with the segment 12 respectively. After that, it is used as a permanent stiffener.

  Here, although not set in the first embodiment shown in the figure, when necessary, when the segments of the communication coupling portion are cut out in both shield tunnels 2 and 4, these shield tunnels are used. An internal support for preventing the deformation of 2 and 4 may be assembled and installed in advance.

  5 and 6 show a shield tunnel communication process, in which a segment of a communication coupling portion between both shield tunnels 2 and 4 is cut open, and a natural ground 8 between both shield tunnels 2 and 4 is excavated to communicate with each other.

  Then, as shown in the connecting member installation step of FIG. 7, the connecting member 22 is installed across the edges of the upper and lower segment rings (covering body 10) of the two shield tunnels 2, 4. The The connecting member 22 is made of a steel plate.

  In this way, the communication portion 23 is formed, but the communication portion 23 becomes a no-pillar and a two-way road tunnel is formed. Here, if necessary, after the connection member 22 is installed, a concrete filling process is performed in which the space between the upper and lower connection members 22 and the steel bent pipe 6 is filled with concrete 24 as shown in FIG. You may do it.

  Moreover, in this 1st Embodiment, it is a chemical | medical solution in the surrounding natural ground through the said steel curved pipe 6 between the said steel curved pipe installation process and a shield tunnel communication process, specifically, before a segment stiffening process. However, if it is not necessary, the ground improvement process may be omitted.

  Moreover, the steel bent pipe 6 for maintaining rigidity may have a double pipe structure including an outer pipe 6a and an inner pipe 6b as shown in FIG. Alternatively, as shown in FIG. 11 (a), an H-shaped steel 6c may be inserted and disposed in the rigid holding steel curved pipe 6.

  Further, the gap in the rigid holding steel curved pipe 6 may be filled with concrete 24 by closing both ends of the rigid holding steel curved pipe 6 with a closing plate (not shown). good. Here, when the rigid holding steel curved pipe 6 has a double-pipe structure, the concrete 24 extends only to the gap inside the inner pipe 6b, as shown in FIGS. 10 (b) to 10 (d). Or filling only the tubular void outside the inner tube 6b, or filling both the inner and outer voids of the inner tube 6b.

  Furthermore, as shown in FIG. 10 and FIG. 11, in the rigid holding steel curved pipe 6, in order to introduce prestress into the rigid holding steel curved pipe 6, in the vicinity of the centroid. A steel wire 28 is disposed through the sheath tube 26 along the entire length, and both ends of the steel wire 28 are fixedly locked to a closing plate (not shown) in a state where tension is applied. May be.

  In addition, although the rigid holding | maintenance steel curved pipe 6 shown in FIGS. 9-11 has a circular cross section, you may employ | adopt not only this but a rectangular cross section.

<< Second Embodiment >>
FIG. 12 to FIG. 20 are schematic diagrams sequentially showing each construction process of the construction method of the glasses-type shield tunnel in the second embodiment, and as in the first embodiment, construction of the branch / merging portion of the underground highway The case where it applies to is illustrated. Here, the steps shown in FIG. 12 to FIG. 14 are exactly the same as those in the first embodiment described above, and therefore the description thereof is omitted.

  By the way, in the second embodiment, after the ground improvement step shown in FIG. 14 is completed, as shown in FIG. 15, the segments 12a of the side portions of the two shield tunnels 2, 4 facing the communication planned connection sites are compensated. A segment stiffening process for stiffening with higher rigidity than the segment 12 of another part by a rigid means and an internal support installation process for installing an internal support for preventing deformation of the tunnel in both shield tunnels are performed. . Here, either the segment stiffening process or the internal support installation process may be performed first, and both processes may be performed before the shield tunnel communication process.

  In the internal support construction installation process, when the segments of the communication coupling portion are cut and expanded in both shield tunnels 2 and 4, internal support for preventing the shield tunnels 2 and 4 from being deformed. The work 20 is assembled and installed in a rectangular cross section.

  In the segment stiffening step, the concrete 13 is filled as a stiffening means inside the segment 12a disposed in the side portions of the shield tunnels 2 and 4 facing the communicating portion. That is, as described in the description of the first embodiment described above, both shield tunnels 2 and 4 are covered with steel segments 12 of the same standard on the entire circumference of their inner peripheral surfaces. Concrete 13 is filled as a stiffening means inside the segment 12a disposed in the side part of both shield tunnels 2, 4 facing the formation site. In other words, when excavating the shield tunnel with the shield machine, the steel segment 12 of the same standard is assembled over the entire circumference, and the concrete segment 13 is filled as a stiffening means into the steel segment 12 at a predetermined position in the subsequent construction. Therefore, when the segments are assembled, segments of different standards are not mixed.

  FIGS. 16 and 17 show a shield tunnel communication process, in which the segment of the part where the two shield tunnels 2 and 4 are planned to be connected is cut open and removed, and the ground 8 between the shield tunnels 2 and 4 is excavated. To communicate with each other.

  Then, as shown in the connecting member installation step of FIG. 18, the connecting member 22 is installed over the respective upper and lower edges of the segment rings (covering body 10) cut out of the shield tunnels 2, 4. The The connecting member 22 is made of a steel plate.

  When the connecting member 22 is installed, the concrete 24 is filled in the gaps between the upper and lower connecting members 22 and the steel bent pipe 6 as shown in the concrete filling step of FIG. Then, when the concrete 24 is hardened, as shown in the support removal process of FIG. 20, the internal support 20 is removed, and a road tunnel having two columns without columns is formed.

  Here, between the steel bent pipe installation step and the internal support installation setting step, there is a configuration including a ground improvement process for injecting a chemical into the surrounding natural ground through the steel bent pipe to improve the ground. However, if it is unnecessary, the ground improvement process may be omitted.

  Further, as in the case of the first embodiment, the rigid steel holding curved pipe 6 has a double pipe structure composed of an outer pipe 6a and an inner pipe 6b as shown in FIG. 10 (a). Also good. Alternatively, as shown in FIG. 11 (a), an H-shaped steel 6c may be inserted and disposed in the rigid holding steel curved pipe 6. Further, the gap in the rigid holding steel curved pipe 6 may be filled with concrete 24 by closing both ends of the rigid holding steel curved pipe 6 with a closing plate (not shown). good. Here, when the rigid holding steel curved pipe 6 has a double-pipe structure, the concrete 24 extends only to the gap inside the inner pipe 6b, as shown in FIGS. 10 (b) to 10 (d). Or filling only the tubular void outside the inner tube 6b, or filling both the inner and outer voids of the inner tube 6b. Further, as shown in FIGS. 10 and 11, in the rigid holding steel curved pipe 6, in order to introduce prestress into the rigid holding steel curved pipe 6, the vicinity of the centroid is arranged. Accordingly, a steel wire 28 is disposed over the entire length of the steel tube 28 through the sheath tube 26, and both ends of the steel wire 28 are fixedly locked to a closing plate (not shown) in a state where tension is applied. Also good.

<< Third Embodiment >>
FIG. 21 to FIG. 29 are schematic views sequentially showing each construction process of the construction method of the glasses-type shield tunnel in the third embodiment. In this case as well, as in the first embodiment, a case where the invention is applied to the construction of a branching / merging portion of an underground highway is illustrated.

  By the way, in the third embodiment, in the glasses-type shield tunnel structure in which the side portions of the plurality of shield tunnels 2 and 4 having a circular cross-section arranged in close proximity are cut and formed in communication connection, the communication connection formation is performed. A stiffening member is provided above and below the communicating portion 23 to be stiffened by connecting the segments of the two shield tunnels 2 and 4, and side portions of both shield tunnels 2 and 4 that face the communicating portion 23. The segment 12a arranged in the above is arranged so as to have a higher rigidity than the segments 12 arranged in other parts in advance when assembled by the shield machine.

  That is, as shown in FIG. 21, in the shield tunnel installation process by the shield machine, when the segments forming the lining body 10 are connected and assembled in a ring shape, both shield tunnels facing the communication portion formation planned site are assembled. As the segments 12a disposed on the side portions 2 and 4, a segment 12a formed with higher rigidity than the segments 12 disposed in other portions is used.

  Here, in the third embodiment, as described above, the segment 12a disposed in the side portion of both shield tunnels 2 and 4 facing the communication portion formation scheduled portion is disposed in another portion. The shield tunnel installation process shown in FIGS. 21 to 29 (FIG. 21), the steel bent pipe installation process (FIG. 22), except that a segment formed with higher rigidity than the segment 12 is disposed in advance. ), Ground improvement process (FIG. 23), internal support installation process (FIG. 24), shield tunnel communication process (FIGS. 25 and 26), connecting member installation process (FIG. 27), concrete filling process (FIG. 28), support Each step of the work removal step (FIG. 29) is exactly the same as in the case of the second embodiment described with reference to FIGS. Therefore, the description is omitted.

  And according to the spectacles type shield tunnel structure of the present invention constituted as the above-mentioned 1st embodiment-3rd embodiment, and the construction method, the following outstanding effects can be produced.

  That is, a stiffening member such as a steel bent pipe 6 that stiffens the shield tunnels 2 and 4 by connecting the segments of the shield tunnels 2 and 4 to each other and stabilizes the structure. When the two shield tunnels 2 and 4 are cut and communicated, the segment 12a disposed in the side portion of the shield tunnels 2 and 4 facing the communication portion 23 is higher than the segments 12 disposed in other portions. Since it is stiffened by rigidity, the bending deformation of the edge of the segment ring at the part to be cut open and communicated can be reduced as much as possible, and thus the stiffening member made of steel bent pipe 6 or the like can be reduced. The required proof stress can be reduced as much as possible. For this reason, the number of installation of the stiffening member can be reduced, or the rigidity of the stiffening member itself can be set low, so that the installation cost can be reduced and the construction period can be shortened.

  Further, the steel curved pipe 6 for maintaining rigidity curved in an arch shape is installed innumerably at a predetermined pitch along the tunnel axis direction (longitudinal direction) above and below the communication coupling portion, and both the shields The connecting members 22 are provided across the edges of the segment rings opened in the tunnels 2 and 4, and the gap between the connecting member 22 and the steel bent pipe 6 is filled with concrete 24 to form both shield tunnels. By integrating 2 and 4, the joint portion between the shield tunnels 2 and 4 arranged side by side can be formed with high rigidity, and the portion can be made non-supported. And since the communication part 23 can be made non-supported in this way, if it is applied to a branching / merging part such as a road, it is possible to smoothly and safely move the vehicle between the shield tunnels 2 and 4. It becomes.

  Moreover, since it is not necessary to make the formation part of a branch merge part into a large-section circular tunnel structure or a large-section rectangular structure by the open-cut method, the influence on the ground can be reduced as much as possible. In addition, both the general part such as the main line and the branching / merging part can be made into an underground tunnel structure without changing the alignment.

  In addition, it is not necessary to separately provide a support structure outside the shield tunnels 2 and 4, and the side portions of the shield tunnels 2 and 4 that face the communication joint 23 and the site where the shield tunnels 2 and 4 are planned to be connected are connected. By stiffening the segment 12a, the structure can be stabilized as much as possible, and the steel bent pipe 6 of the stiffening member can be installed only by the construction from the inside of the shield tunnels 2, 4, so the construction cost It is possible to achieve a reasonable structure by reducing the construction period, shortening the construction period, and reducing the exclusive area.

  Further, a steel bending pipe 6 for maintaining rigidity and a steel bending pipe 16 for injecting chemical liquid are provided separately, and the steel bending pipe 16 for injecting chemical liquid is provided outside the rigid bending steel bending pipes 6 and 6. Therefore, the chemical solution injected into the natural ground 8 can be easily transmitted to the inner portions sandwiched between the upper and lower steel curved pipes 6.

  Further, the rigid steel holding curved pipe 6 has a double pipe structure comprising an inner pipe 6a and an outer pipe 6b, or an H-shaped steel 6c is inserted into the rigid holding steel bent pipe 6. It is possible to communicate with each other by arranging or introducing a prestress by filling a gap in the steel bent pipe 6 for maintaining rigidity with a concrete 24, and further arranging a tensioned steel wire 28. A further increase in rigidity of the joint can be achieved.

It is the schematic which shows the shield tunnel installation process in 1st Embodiment of the construction method of the glasses-type shield tunnel which concerns on this invention. It is the schematic which shows a steel bent pipe installation process same as the above. It is the schematic which shows a ground improvement process same as the above. It is the schematic which shows a segment stiffening process same as the above. It is the schematic which shows the segment opening step of a shield tunnel communication process same as the above. It is the schematic which shows the natural ground excavation stage of a shield tunnel communication process same as the above. It is the schematic which shows a connection member installation process same as the above. It is the schematic which shows a concrete filling process same as the above. It is an expanded view which shows the A section in FIG. 2 from an inner side. It is sectional drawing of the various modified examples at the time of making the steel curved pipe for rigidity maintenance into a double pipe, (a) is a thing of the double pipe structure which does not fill concrete, (b) is inside the inner space of an inner pipe (C) shows that the outer space of the inner tube is filled with concrete, and (d) shows that the inner space of the inner tube is filled with concrete. It is sectional drawing of the various modifications at the time of inserting H-shaped steel in the steel curved pipe for rigidity maintenance, (a) is what does not fill concrete, (b) shows what was filled with concrete. It is the schematic which shows the shield tunnel installation process in 2nd Embodiment of the construction method of the glasses-type shield tunnel which concerns on this invention. It is the schematic which shows a steel bent pipe installation process same as the above. It is the schematic which shows a ground improvement process same as the above. It is the schematic which shows a segment stiffening process and an internal support installation setting process same as the above. It is the schematic which shows the segment opening step of a shield tunnel communication process same as the above. It is the schematic which shows the natural ground excavation stage of a shield tunnel communication process same as the above. It is the schematic which shows a connection member installation process same as the above. It is the schematic which shows a concrete filling process same as the above. It is the schematic which shows a support work removal process same as the above. It is the schematic which shows the shield tunnel installation process in 3rd Embodiment of the construction method of the glasses-type shield tunnel which concerns on this invention. It is the schematic which shows a steel bent pipe installation process same as the above. It is the schematic which shows a ground improvement process same as the above. It is the schematic which shows an internal support installation setting process same as the above. It is the schematic which shows the segment opening step of a shield tunnel communication process same as the above. It is the schematic which shows the natural ground excavation stage of a shield tunnel communication process same as the above. It is the schematic which shows a connection member installation process same as the above. It is the schematic which shows a concrete filling process same as the above. It is the schematic which shows a support work removal process same as the above.

Explanation of symbols

2 1st shield tunnel 4 2nd shield tunnel 6 Steel curved pipe (stiffening member) for maintaining rigidity
6a Outer pipe 6b Inner pipe 6c H-shaped steel 8 Ground mountain 10 Covering body 12 Segment 12a Segment 13 facing the communicating portion Concrete (stiffening means)
14 Reinforcing ribs 16 Curved steel pipe 18 for injecting chemicals Ground improvement area 20 Internal support 21 Strut (stiffening means)
22 connecting member 23 communicating portion 24 concrete 26 sheath tube 28 steel wire

Claims (18)

It is a glasses-type shield tunnel structure in which the side portions of a plurality of shield tunnels having a circular cross-section adjacent to each other are cut and formed in communication connection,
A stiffening member that stiffens and connects between the segments of both shield tunnels is provided above and below the communication portion formed to be connected and connected.
The segments disposed in the side portions of both tunnels facing the communication portion are formed with higher rigidity than the segments disposed in other portions.
Spectacle-type shield tunnel structure. It is a glasses-type shield tunnel structure in which the side portions of a plurality of shield tunnels having a circular cross-section adjacent to each other are cut and formed in communication connection,
A stiffening member that stiffens and connects between the segments of both shield tunnels is provided above and below the communication portion formed to be connected and connected.
Stiffening means is provided on the side portions of both tunnels facing the communicating portion to increase the rigidity of the segments disposed on the side portions as compared with the segments of other portions.
Spectacle-type shield tunnel structure.   3. The glasses-type shield tunnel structure according to claim 2, wherein the stiffening means is a support column. The segments of both shield tunnels are made of steel segments, and the stiffening means is made of concrete filled in the segments disposed in the side portions of both shield tunnels facing the communicating portion.
The glasses-type shield tunnel structure according to claim 2. A method for constructing an eyeglass-type shield tunnel in which side portions of a plurality of shield tunnels having a circular cross-section arranged in close proximity are cut and formed in communication connection,
In the segment disposed in the side part of both shield tunnels facing the formation planned part of the communication part, both shield tunnels are formed in advance using a higher rigidity than the segment of the other part,
After providing and stiffening a stiffening member that connects between the segments of both shield tunnels above and below the planned formation site of the communication part to be connected and connected, the communication part is cut and formed.
The construction method of the glasses type shield tunnel characterized by this. A method for constructing an eyeglass-type shield tunnel in which side portions of a plurality of shield tunnels having a circular cross-section arranged in close proximity are cut and formed in communication connection,
While stiffening by providing a stiffening member that connects between the segments of both shield tunnels above and below the formation planned portion of the communication portion to be connected and connected,
After the stiffening means stiffens the segments of the side portions of both shield tunnels facing the formation planned portion of the communication portion with higher rigidity than the segments of the other portions, the communication portion is cut and formed.
The construction method of the glasses type shield tunnel characterized by this. A method for constructing an eyeglass-type shield tunnel in which side portions of a plurality of shield tunnels having a circular cross-section arranged in close proximity are cut and formed in communication connection,
In the ground on both sides of the upper and lower sides of the connecting joint between the shield tunnels, an arcuate steel curved pipe is bridged from one side of the shield tunnel to the other by using a curved boring device. A steel bent pipe installation step of installing a predetermined number of pieces at a predetermined pitch along
A segment stiffening step of stiffening the segments of the side portions of both shield tunnels facing the communication connection planned portion with higher rigidity than the segments of other portions by means of stiffening;
After completion of the steel bent pipe installation process and the segment stiffening process, a shield tunnel communication is performed by opening a segment of a communication joint portion of the shield tunnels and excavating a ground between the shield tunnels. Process,
A connecting member installation step of installing a connecting member across the edges of the segment rings opened in both shield tunnels;
A construction method of a glasses-type shield tunnel characterized by comprising:   The method for constructing a glasses-type shield tunnel according to claim 7, further comprising a concrete filling step of filling the gap between the connection member and the steel bent pipe with concrete after the connection member installation step. . An internal support installation step that is installed before the shield tunnel communication step and installs an internal support to prevent deformation of the tunnel in both shield tunnels;
After the hardening of the concrete filled in the gap between the connecting member and the steel bent pipe, a support removal process for removing the internal support,
The method for constructing a glasses-type shield tunnel according to claim 7, comprising:   Between the steel bent pipe installation step and the shield tunnel communication step, a ground improvement step is provided in which a chemical solution is injected into the ground from a chemical injection port formed in a segment of the shield tunnel to improve the ground. The construction method of the glasses-type shield tunnel according to any one of claims 7 to 9.   A ground improvement step of injecting a chemical solution into a surrounding natural ground through the steel curved pipe between the steel bent pipe installation step and the shield tunnel communication step is provided. The construction method of the glasses-type shield tunnel in any one of 7-10.   In the steel curved pipe installation step, a rigid steel bending pipe and a chemical liquid injection steel curved pipe are separately provided, and the chemical liquid injection steel curved pipe is the rigid holding steel curved pipe. The method for constructing a glasses-type shield tunnel according to claim 11, wherein the glasses-type shield tunnel is arranged with a position shifted outside.   The method for constructing a glasses-type shield tunnel according to any one of claims 7 to 12, wherein the stiffening means in the segment stiffening step is a column.   The segments of both shield tunnels are steel segments, and the stiffening means in the segment stiffening step is filled into the segments disposed in the side portions of both shield tunnels facing the communication portion. It consists of concrete, The construction method of the glasses-type shield tunnel in any one of Claims 7-13 characterized by the above-mentioned.   The construction method for a glasses-type shield tunnel according to any one of claims 7 to 14, wherein the rigid bent steel pipe has a double pipe structure including an inner pipe and an outer pipe.   The method for constructing a glasses-type shield tunnel according to any one of claims 7 to 15, wherein an H-shaped steel is inserted and disposed in the rigid steel bending pipe.   The method for constructing a glasses-type shield tunnel according to any one of claims 7 to 16, wherein concrete is filled in the steel bent pipe for maintaining rigidity.   18. The steel wire to which tension is applied is disposed in the bent steel pipe for maintaining rigidity in order to introduce prestress into the bent steel pipe. The construction method of the glasses-type shield tunnel as described in 1.