JP4934416B2 - How to construct a junction and junction of shield tunnel - Google Patents

Description

  In the present invention, when a subsequent tunnel (for example, a ramp tunnel) enters obliquely with respect to a preceding tunnel (for example, a main tunnel) and merges the ramp tunnel with the main tunnel, or the ramp tunnel exits diagonally from the main tunnel. The present invention also relates to a method for constructing a branching / merging portion of a shield tunnel used when a ramp tunnel is branched from a main tunnel.

  In urban areas, several examples of underground road tunnels with a length of several kilometers using the shield method are planned as one of the measures against traffic congestion. In the case of an underground road tunnel, it is necessary to install several entrance / exit ramps in the middle of the main line due to the formation of a traffic network. However, because the main line is underground, it is difficult to connect the lamps.

  As a lamp connection construction method, there have been a method of construction by open cutting and a method of non-cutting construction. In the method of construction by excavation, excavation is carried out by installing a mountain stop in a long section along the main tunnel, and a ramp part is constructed within that excavation. In this method, it is necessary to dedicate the ground surface (mainly roads) for a long time. On the other hand, in the non-open-cutting method, a main tunnel and a ramp tunnel are installed in the ground, then the surrounding ground is improved and protected from both tunnels, and connected to establish a ramp.

However, the method of construction by open-cutting has a problem that greatly affects the traffic flow.
In the method of non-open cutting construction, a main tunnel and a ramp tunnel are installed side by side, and a structure of a scale that extrapolates them is constructed under the action of underground soil water pressure, which requires a large construction period and cost. Become. As described above, branching from one tunnel to another tunnel is very expensive to improve the ground of the surrounding ground, hinders shortening of the construction period, and is uneasy in terms of safety.

By the way, an invention has been proposed in which a lamp tunnel is obliquely entered into a main tunnel and the lamp tunnel joins the main tunnel (see Patent Document 1).
Japanese Patent No. 2751636

  However, when the technique of Patent Document 1 is implemented, there are the following difficult problems.

  First of all, an efficient and economical construction method for performing ground improvement for facilitating excavation and excavation by a shield machine according to the cutting situation has not been solved.

  Secondly, at the junction between the main tunnel and the ramp tunnel, a large occupied area is required for the merge construction, but an efficient construction method for reducing the occupied area has not been solved.

  Thirdly, when the main tunnel and the ramp tunnel are merged, the main tunnel side and the ramp tunnel side are opposed to each other, and a large-scale opening is required to dismantle many segments that are no longer needed. An efficient work method is still unsolved.

The present invention has been made in view of the above-mentioned problems, and when joining the succeeding tunnel to the preceding tunnel, the construction can be performed safely and efficiently, and the construction period can be shortened and the construction cost can be greatly reduced. Thus, an object of the present invention is to provide a method for constructing a branching / merging portion of a shield tunnel that can cope with various merging angles.

  The present invention employs the following means in order to solve the aforementioned problems.

That is, the method for constructing the branching junction of the shield tunnel of the present invention is as follows.
Used when the succeeding tunnel is obliquely entered with respect to the preceding tunnel and the succeeding tunnel is merged with the preceding tunnel, or when the succeeding tunnel is obliquely exited from the preceding tunnel and the succeeding tunnel is branched from the preceding tunnel A method for constructing a branching junction of a shield tunnel,
Before joining the early and succeeding tunnels and at the early stage of joining,
A filling material filling step of filling the filling material in the branching junction on the preceding tunnel side;
Compared to the segment that is permanently installed in the preceding tunnel, the preceding tunnel construction process in which a cutable segment that can be cut by the trailing shield machine is provided in the branching junction on the preceding tunnel side instead of the permanent segment,
The following tunnel entering into the preceding tunnel obliquely entering the preceding tunnel by excavating while constructing the succeeding tunnel by the following shield excavator and cutting the cutable segment on the buried material and the preceding tunnel side. Construction process,
A natural ground improvement process for improving the natural ground around the branch and junction part from both tunnels,
Remove the permanent segment of the portion where the following incoming tunnel and the preceding tunnel face each other, open the opposite portions of both tunnels, remove the embedding material around this opening, and without cutting the preceding tunnel A side surface communication step of removing the remaining cuttable segments and communicating opposite side surfaces of the preceding tunnel side and the subsequent tunnel side; and
Building part construction process to build the building parts of both tunnels,
It is characterized by having.

  Note that, in the filling material filling step, depending on the relationship between the distance between the center of the tunnel and the cutting portion angle when the trailing shield engraver enters the preceding tunnel, the branch merging portion on the preceding tunnel side Is covered with a temporary wall, and the embedded material is filled into the branch joint part covered with the temporary wall. Further, in the preceding tunnel construction step, the trailing shield excavator is arranged at the branching junction on the preceding tunnel side according to the relationship between the distance between the tunnel centers and the cutting portion angle when entering the preceding tunnel. The cuttable segment is determined.

  According to this configuration, the size of the structure that extrapolates both tunnels can be minimized by cutting and penetrating the subsequent tunnel into the lining body that includes the cutable segment of the preceding tunnel, and the safety of the structure and the construction period and cost can be reduced. Reduction can be achieved.

  In the method for constructing a branching / merging portion of a shield tunnel according to the present invention, the cuttable segment is a new material concrete member including a carbon fiber reinforcing material having a small diameter and a lightweight aggregate. The carbon fiber reinforcing material is a fiber reinforced plastic (CFRP = Carbon Fiber Reinforced Plastics) using carbon fiber, and a carbon fiber reinforcing material made of a lattice material is used. In addition, as a measure for preventing segment segmentation, the cover of the cuttable segment may be reduced in the covering of the lattice material, mixed with a fiber material other than carbon, or attached with a fiber sheet. Furthermore, an injection pipe used for water stoppage measures in the side surface communication process is embedded in the cuttable segment in advance. Further, the cuttable segment may adjust the member strength and the member thickness in consideration of improvement of the machinability. According to this configuration, cutting can be performed by improving a new material concrete member (for example, a new material concrete member used in the NOMST (registered trademark) construction method) that has a proven record as a wall member for direct start (reaching) of a shield machine. By using it as a segment, the excavation speed can be increased (for example, excavation of 20 mm / min in direct start).

  In the method for constructing a junction / junction portion of a shield tunnel according to the present invention, the cuttable segment can further increase the excavation speed by roughening the cutting surface cut by the shield excavator.

  In the method for constructing a branching / merging portion of a shield tunnel according to the present invention, a position detection means is provided in the branching / merging portion on the preceding tunnel side, and in the subsequent tunnel approaching construction step, the following shield-side shield excavator detects the position. Based on the position information of the means, the vehicle enters the preceding tunnel. According to this configuration, it is possible to improve the position accuracy of the subsequent tunnel approach construction, and it is possible to eliminate useless construction due to the excavation position error.

  In the shield tunnel branching junction construction method according to the present invention, in the natural ground improvement step, according to the relationship between the distance between the tunnel centers and the cutting portion angle when the trailing shield excavator enters the preceding tunnel. In addition to improving the natural ground by injecting chemicals, work to reinforce the natural ground using a shearing girder that passes the shape steel between the two tunnels (Kanzashi Girder method), and crossing the press-fit long steel pipes alternately Reinforcement construction (roof shield construction method) using either reinforcement work (AGF construction method) or construction work of reinforcing ground using a roof shield is performed. According to this configuration, depending on the situation where the shield excavator enters the preceding tunnel, the reinforcement work using either the girders girder method, the AGF method, or the roof shield method is properly used. Natural ground improvement work becomes possible.

  In the method for constructing a branching junction of shield tunnels according to the present invention, in the side surface communication step, depending on the relationship between the distance between the center of the tunnel and the angle of the cutting part when the trailing shield machine enters the preceding tunnel. The method further includes a step of installing an intermediate wall at the branching / merging portion. Further, in the side surface communication step, depending on the relationship between the distance between the center of the tunnel and the cutting portion angle when the trailing shield machine enters the preceding tunnel, a thick segment other than the side surface communication portion is used. And the two upper and lower thick segments facing each other on the preceding tunnel side and the succeeding tunnel side are joined with steel beams to form two upper and lower floor slabs. . Further, the step of joining the thick segments with steel beams to form two upper and lower floor slabs is a communication in which the thick segments on the preceding tunnel side and the thick segments on the subsequent tunnel side face each other. The steel girder having a width Li (Ln> Li) smaller than the interval Ln of the communication work part is disposed in the construction part, the steel girder and the thick segment are joined by a joining member, and the steel The floor slab is formed by placing ultra-high-strength concrete in the gap between the joints of the girder and the thick segment.

  According to this configuration, the intermediate wall is provided at the branching / merging portion according to the situation in which the trailing shield machine enters the preceding tunnel, or the leading and trailing thick plates are installed without installing the intermediate wall. By connecting the two segments with steel beams to form two upper and lower floor slabs, it is possible to perform efficient side communication work. In the communication construction part, the downstream tunnel is obliquely entered with respect to the preceding tunnel, so the interval Ln of the communication construction part changes (becomes narrower in the traveling direction) and the shape of the floor slab is not uniform. However, in the communication construction part, the floor slab is pressed while being pressed by earth and water pressure. Therefore, the steel large beam having a width Li (Ln> Li) smaller than the interval Ln of the communication construction part is arranged, and the joining member By joining the steel girder and the thick segment and placing ultra-high strength concrete in the gap between the joints, it is possible to perform efficient side surface communication.

In the method for constructing a junction portion of a shield tunnel of the present invention, in the filling material filling step, a space in which the filling material is not filled by installing a cylindrical member between the cuttable segment and the temporary wall in advance. A bit exchange work space construction step is provided, in which the beat of the trailing shield machine is exchanged by this space. According to this configuration, a plurality of bit replacement work spaces are provided in advance at positions where the bits are worn and need to be replaced, and the bits can be replaced by human power at those positions, enabling efficient excavation. Become.

  According to the present invention, when joining the succeeding tunnel to the preceding tunnel, the construction can be performed safely and efficiently, the construction period can be shortened and the construction cost can be greatly reduced, and various joining angles can be dealt with. It is possible to provide a method for constructing a branching junction of a shield tunnel.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings. In the following explanation, the main tunnel with a large diameter in the middle of construction, which has started excavation in advance, will follow a ramp tunnel with a small diameter (following tunnel) at an approach angle close to the parallel, and then merge. The case where it aims is demonstrated. In addition, FIG. 1 is a perspective view which shows the outline of the branch merging part construction method of the shield tunnel of this invention. FIG. 2 is a plan view of the main line 1a and the lamp 2a constructed at the branching junction of the main tunnel 1 and the lamp tunnel 2. FIG.

  The method for constructing the branching junction of the shield tunnel is used before joining the main tunnel 1 and the ramp tunnel 2 and at the initial stage of joining. That is, the method for constructing the branching junction of the shield tunnel according to the present embodiment is the main tunnel construction process in the case where the ramp tunnel 2 is obliquely entered into the main tunnel 1 and the main tunnel 1 is merged with the main tunnel 1. , A filling material filling process, a lamp tunnel approach construction process, a natural ground improvement process, a side surface communication process, and a building part construction process.

  In the main tunnel construction process, when the main tunnel 1 is constructed, the cutable segment 6 that can be cut by the shield machine 3 in advance is connected to the branch junction of the main tunnel 1 with the ramp tunnel 2 (the two-dot chain line portion in FIG. 1). It is a process of constructing the main tunnel 1 as provided in FIG. The cutable segment 6 is a new material concrete member including a small-diameter carbon fiber reinforcement and a lightweight aggregate. The carbon fiber reinforcing material is a fiber reinforced plastic (CFRP = Carbon Fiber Reinforced Plastics) using carbon fiber, and a carbon fiber reinforcing material made of a lattice material is used. In addition, as a measure for preventing segment segmentation, the gridable material 6 is made small in the cuttable segment 6, fiber materials other than carbon are mixed, and fiber sheets are attached. Further, an injection pipe used for water stoppage measures in the side surface communication step is embedded in the cutable segment 6 in advance. Further, the cutable segment 6 may adjust the member strength and the member thickness in consideration of improvement of the machinability. A new material concrete member (for example, a new material concrete member used in the NOMST (registered trademark) method) improved as a wall member for direct start (reaching) of the shield machine 3 is used as a cutable segment. By doing so, the digging speed can be increased (for example, digging at 20 mm / min for direct start).

  It should be noted that the design of how many cutable segments 6 are arranged at the branching junction (the two-dot chain line portion in FIG. 1) of the main tunnel 1 with the lamp tunnel 2 is between the main tunnel 1 and the ramp tunnel 2. It is determined by the relationship with the angle of the cutting portion on the main tunnel 1 side cut by the shield machine 3 of the ramp tunnel 2 determined from the center distance C (see FIG. 14) (see the graph of FIG. 15). That is, at the position where the center distance C is far, the arrangement of the cuttable segments 6 is 0 to 1 in the case of this embodiment, but the center distance C is close and the cutting portion angle on the main tunnel 1 side is maximum. Then, the maximum number becomes three, and thereafter the number decreases to 1 and 0 as the center distance C becomes shorter.

Further, a plurality of position detection sensors (position detection means) are installed in the cutable segment 6 of the main tunnel side branch junction. The position detection sensor has a transmitter that outputs a signal indicating position (position information). The signal indicating the position indicates a cutting position on the main tunnel side, and is received by a receiver provided in the shield machine 3.

  The middle filling material filling step is a step of filling the middle joining material into the branch and merge portion on the main tunnel side, and the distance C between the tunnel centers when the lamp side shield machine 3 enters the main tunnel (see FIG. 14, and FIG. 15) and the cutting portion angle, as shown in FIG. 3, the outer side of the cutable segment 6 of the branching junction on the main line tunnel side is covered with the temporary wall 7 and covered with the temporary wall 7. The intermediate junction 8 is filled in the branched junction. Here, fluidized soil or the like is used as the embedding material 8.

  Further, the filling material filling step is a step of arranging a cylindrical member between the cuttable segment 6 and the temporary wall 7 and constructing a plurality of spaces not filled with the filling material 8 (replacement work space construction step). have. As shown in FIG. 16, this space is a space for exchanging the bits 3a of the shield machine 3 manually. A bit replacement work space S is provided in advance at the position (single or multiple locations) where the bit 3a is worn and needs to be replaced, and the bit 3a is replaced by human power at that position, thereby efficiently excavating. Is possible.

  The natural ground improvement process is a process for improving the natural ground around the branching junction. This natural ground improvement process is a process for injecting a natural ground improvement agent (chemical) around the junction of the main tunnel 1 and the lamp tunnel 2 to prevent water from entering during the side surface communication process.

  The natural ground improvement process is performed by injecting chemical solution according to the relationship between the distance C between the tunnel centers when the lamp-side shield machine 3 enters the main tunnel (see FIGS. 14 and 15) and the cutting portion angle. In addition to the improvement of the natural ground, the work to reinforce the natural ground by using a shear girder that passes the shape steel between the two tunnels (Kanzashi girder method), the work to reinforce the natural ground by alternately intersecting press-fit long steel pipes ( Reinforcement work (roof shield method) using either the AGF method) or the work of reinforcing the ground using a roof shield. Details of this reinforcement work will be described later.

  In the ramp tunnel entry construction process, the shield tunneling machine 3 enters the main tunnel obliquely in the traveling direction, and excavates while cutting the ground mountain, the cutable segment 6 of the main tunnel 1 and the embedding material 8, and the ramp tunnel 2 It is a process of constructing. In this ramp tunnel approach construction process, the shield machine 3 confirms the cutting position (entrance position) based on the output position information of a position detection sensor (for example, a non-contact type sensor such as a magnetic sensor) provided in the main tunnel 1, Enter main tunnel 1 In this ramp tunnel entry construction process, the position detection means can improve the position accuracy of the lamp tunnel entry construction, and therefore, wasteful construction due to an excavation position error can be eliminated.

  In the side surface communication step, both tunnels are reinforced with temporary struts 9, and then the permanent segment 5 at the part where the entered ramp tunnel 2 and main line tunnel 1 face each other is opened. This is a step of removing the temporary wall 7 and removing the remaining cuttable segments 6 of the main tunnel 1 without cutting, thereby allowing the tunnels 1 and 2 to communicate with each other on the side surface.

  Further, in the side surface communication step, the intermediate wall 13 (see FIG. 2) is installed at the branch junction at the initial stage (the A position to the E position described later) when the shield machine 3 enters the main tunnel.

  Further, in the side surface communication process, in the period excluding the initial stage when the shield machine 3 enters the main tunnel (F position to I position, which will be described later), each of the thick molds at the upper and lower two locations facing each other on the main tunnel side and the ramp tunnel side. These two segments are joined with steel beams to form two floor slabs. Details of this side communication work will be described later.

  The building part building process is a process of building the building parts of both tunnels. Details of this construction part construction work will be described later.

  As described above, the relationship between the distance C between the tunnel centers when the lamp-side shield machine 3 enters the main tunnel (see FIGS. 14 and 15) and the cutting portion angle (positions A to J in FIG. 1). ) Depending on the construction process used. Next, the construction process to be used will be described based on FIGS. 3 to 13 in accordance with the respective situations at positions A to J in FIG.

  3 to 13, (a) shows a construction drawing at the time of cutting, (b) shows a construction drawing at the time of temporary installation, and (C) shows a construction drawing at the time of construction.

  Note that the position A in FIG. 1 indicates a position where the ramp tunnel 2 and the main tunnel 1 are circumscribed (cutting portion angle 0 °) (see FIG. 3). The position B in FIG. 1 is a position where the ramp tunnel 2 makes a face on the inner surface of the main tunnel 1 (when the thickness of the cutable segment 6 is 50 cm equivalent to the general part (permanent segment): cutting part angle 14.72 °) (See FIG. 4). A position C in FIG. 1 indicates a position (cutting portion angle 20.79 °) where the ramp tunnel 2 has come to a portion where two pieces of the cutable segment 6 of the main tunnel 1 are used (see FIG. 5). The D position in FIG. 1 indicates the position (cutting portion angle 35.02 °) where the ramp tunnel 2 cuts to the construction limit position of the main tunnel 1 (see FIG. 6). The position E in FIG. 1 indicates the position (cutting section angle 39.00 °) at which the ramp tunnel 2 has advanced to the final position where the intermediate wall is installed at the branching junction in the side surface communication step (see FIG. 7). The F position in FIG. 1 indicates end installation (cutting portion angle 39.00 °) in which the intermediate wall is not provided at the branch joint portion in the side surface communication step at the same position as E (see FIG. 8). The G position in FIG. 1 indicates the position where the ramp tunnel 2 cuts to the acceleration / deceleration section of the main tunnel 1 (cutting section angle 47.85 °: the same section continues for about 100 m) (see FIG. 10). The H position in FIG. 1 indicates a position where the ramp tunnel 2 advances into the main tunnel 1 and the cut end of the main tunnel 1 is maximized (cutting portion angle 48.92 °) (see FIG. 11). The I position in FIG. 1 indicates the position where the ramp tunnel 2 advances into the main tunnel 1 and the construction limits of the ramp tunnel 2 and the main tunnel 1 are inscribed (cutting portion angle 20.55 °) (see FIG. 12). 1 indicates a case where the widened portion is performed in parallel with the standard construction by adopting the M-ESS method, which is a partial widening method, between the H position and the I position (see FIG. 13).

[Description of position A]
As shown in the construction drawing at the time of cutting (see FIG. 3A), in the main tunnel construction process, not the permanent segment 4 but the cutable segment 6 (one piece) is provided at the branch and merge part on the main tunnel 1 side. deep. Further, in the middle filling material filling step, the outer side of the cutable segment 6 of the main tunnel side branch joint portion is covered with the temporary wall 7, and the middle joint material 8 is filled into the branch joint portion covered with the temporary wall 7.

  As shown in the construction drawing at the time of temporary installation (see FIG. 3B), in the ground improvement process, a ground improvement agent is injected around the junction of the main tunnel 1 and the ramp tunnel 2. Further, temporary struts 9 are erected on the ramp tunnel 2 and the main tunnel 1 as reinforcement work. Then, in the side surface communication step, the segment of the part where the entered lamp tunnel 2 and the main line tunnel 1 face each other is removed from the lamp-side permanent segment 5 and opened. The wall 7 is removed, the uncuttable segment 6 remaining in the main tunnel 1 without being cut is removed, and the two tunnels 1 and 2 are communicated with each other on the side surface.

  As shown in the construction drawing at the time of construction (see FIG. 3C), in the side surface communication step, the intermediate wall 13 is installed at the branch junction. In FIG. 3C, 11 indicates the building limit line of the main tunnel 1 based on the road structure ordinance, and 12 indicates the building limit line of the ramp tunnel 2. Then, in the construction part construction process, construction parts of both tunnels (main lane 1a and ramp lane 2a shown at position A in FIG. 2) are constructed.

[Description of position B]
As shown in the construction drawing at the time of cutting (see FIG. 4A), in the main tunnel construction process, not the permanent segment 4 but the cutable segment 6 (one piece: angle of the cutting portion) at the branch merging portion on the main tunnel 1 side. 14.72 °). Further, in the middle filling material filling step, the outer side of the cutable segment 6 of the main tunnel side branch joint portion is covered with the temporary wall 7, and the middle joint material 8 is filled into the branch joint portion covered with the temporary wall 7.

  As shown in the construction drawing at the time of temporary installation (see FIG. 4B), in the ground improvement process, a ground improvement agent is injected around the junction of the main tunnel 1 and the ramp tunnel 2. Further, temporary struts 9 are erected on the ramp tunnel 2 and the main tunnel 1 as reinforcement work. Then, in the side surface communication step, the segment of the part where the entered lamp tunnel 2 and the main line tunnel 1 face each other is removed from the lamp-side permanent segment 5 and opened. The wall 7 is removed, the uncuttable segment 6 remaining in the main tunnel 1 without being cut is removed, and the two tunnels 1 and 2 are communicated with each other on the side surface.

  As shown in the construction drawing at the time of construction (refer to FIG. 4C), the intermediate wall 13 is installed at the branch junction in the side surface communication step. In FIG. 4 (c), 11 indicates the building limit line of the main tunnel 1 based on the road structure ordinance, and 12 indicates the building limit line of the ramp tunnel 2. And in a building part construction process, the building parts (the main lane 1a and the ramp lane 2a which are shown in the B position of Drawing 2) of both tunnels are built.

[Explanation of position C]
As shown in the construction drawing at the time of cutting (see FIG. 5 (a)), in the main tunnel construction process, not the permanent segment 4 but the cutable segment 6 (two pieces: the angle of the cutting section) at the branch merging portion on the main tunnel 1 side. 20.79 °) is provided. Further, in the middle filling material filling step, the outer side of the cutable segment 6 of the main tunnel side branch joint portion is covered with the temporary wall 7, and the middle joint material 8 is filled into the branch joint portion covered with the temporary wall 7. Furthermore, in order to prevent deformation of the main tunnel 1 due to impact during excavation, a plurality of deformation prevention works 15 are provided. The deformation prevention work 15 is removed at the time of construction.

  As shown in the construction drawing at the time of temporary installation (see FIG. 5 (b)), in the natural ground improvement process, the removal part becomes wide, so the shape steel 14 is handed over the upper and lower parts of both tunnels (referred to as "Kanzashi-girder"). After reinforcement, a ground improvement agent is injected around the hairpin girder 14. Temporary struts 9 and 9 are erected on the ramp tunnel 2 and the main line tunnel 1 as reinforcement work. Further, as a reinforcement work, a plurality of deformation prevention works 15 are provided in order to prevent the deformation of both tunnels 1 and 2. Next, in the side surface communication step, the segment of the part where the entered lamp tunnel 2 and the main line tunnel 1 face each other is removed from the lamp side permanent segment 5 and opened, and the buried material 8 and the temporary wall 7 around the opening are removed. After removal, the uncuttable segment 6 remaining in the main tunnel 1 is removed and both tunnels 1 and 2 are communicated with each other on the side surface.

  As shown in the construction drawing at the time of construction (refer to FIG. 5C), the intermediate wall 13 is installed at the branch junction in the side surface communication step. Here, the upper and lower ends of the intermediate wall 13 are widened and connected to the permanent segments 4 and 5 due to the positional relationship between the two tunnels. In FIG. 5C, 11 indicates the building limit line of the main tunnel 1 based on the road structure ordinance, and 12 indicates the building limit line of the ramp tunnel 2. Furthermore, in the construction part construction process, construction parts (main lane 1a and ramp lane 2a shown at position C in FIG. 2) of both tunnels are constructed.

[Description of D position]
As shown in the construction drawing at the time of cutting (see FIG. 6A), in the main tunnel construction process, not the permanent segment 4 but the cutable segment 6 (two pieces: cutting section angle) at the branch and merge section on the main tunnel 1 side. 35.02 °). Further, in the middle filling material filling step, the outer side of the cutable segment 6 of the main tunnel side branch joint portion is covered with the temporary wall 7, and the middle joint material 8 is filled into the branch joint portion covered with the temporary wall 7. Furthermore, in order to prevent deformation of the main tunnel 1 due to impact during excavation, a plurality of deformation prevention works 15 are provided. The deformation prevention work 15 is removed at the time of construction.

  As shown in the construction drawing at the time of temporary installation (see FIG. 6B), the ground improvement agent 10 is injected around the junction of the main tunnel 1 and the lamp tunnel 2 in the ground improvement process. Thus, when a removal part is narrow, it can respond only by injection | pouring. Further, temporary struts 9 and 9 are erected as reinforcement work in the ramp tunnel 2 and the main tunnel 1 respectively. Further, as a reinforcement work, in order to prevent the lamp tunnel 2 from being deformed, a plurality of deformation prevention works 15 are provided on the lamp tunnel 2 side. Next, in the side surface communication step, the segment of the part where the entered lamp tunnel 2 and the main line tunnel 1 face each other is removed from the lamp side permanent segment 5 and opened, and the buried material 8 and the temporary wall 7 around the opening are removed. After removal, the uncuttable segment 6 remaining in the main tunnel 1 is removed and both tunnels 1 and 2 are communicated with each other on the side surface.

  As shown in the construction drawing at the time of construction (refer to FIG. 6C), the intermediate wall 13 is installed at the branch junction in the side surface communication step. In FIG. 6C, 11 indicates the building limit line of the main tunnel 1 based on the road structure ordinance, and 12 indicates the building limit line of the ramp tunnel 2. In addition, the construction limit lines 11 and 12 of both tunnels have touched in D position, and the intermediate wall 13 is located in the boundary part. Furthermore, in the construction part construction process, construction parts (main lane 1a and ramp lane 2a shown at position D in FIG. 2) of both tunnels are constructed.

[Explanation of position E]
As shown in the construction drawing at the time of cutting (see FIG. 7A), in the main tunnel construction process, not the permanent segment 4 but the cutable segment 6 (two pieces: angle of the cutting section) at the branch and merge part on the main tunnel 1 side. 39.00 °). Further, in the middle filling material filling step, the outer side of the cutable segment 6 of the main tunnel side branch joint portion is covered with the temporary wall 7, and the middle joint material 8 is filled into the branch joint portion covered with the temporary wall 7. Furthermore, in order to prevent deformation of the main tunnel 1 due to impact during excavation, a plurality of deformation prevention works 15 are provided. The deformation prevention work 15 is removed at the time of construction.

  As shown in the construction drawing at the time of temporary installation (see FIG. 7B), in the ground improvement process, the ground improvement agent 10 is injected around the junction of the main tunnel 1 and the ramp tunnel 2. Further, temporary struts 9 and 9 are erected as reinforcement work in the ramp tunnel 2 and the main tunnel 1 respectively. Further, as a reinforcement work, in order to prevent the lamp tunnel 2 from being deformed, a plurality of deformation prevention works 15 are provided on the lamp tunnel 2 side. Next, in the side surface communication step, the segment of the part where the entered lamp tunnel 2 and the main line tunnel 1 face each other is removed from the lamp side permanent segment 5 and opened, and the buried material 8 and the temporary wall 7 around the opening are removed. After removal, the uncuttable segment 6 remaining in the main tunnel 1 is removed and both tunnels 1 and 2 are communicated with each other on the side surface.

  As shown in the construction drawing at the time of construction (refer to FIG. 7C), the intermediate wall 13 is installed at the branch junction in the side surface communication step. In FIG. 7C, 11 indicates the building limit line of the main tunnel 1 based on the road structure ordinance, and 12 indicates the building limit line of the ramp tunnel 2. In the code | symbol 11 and the code | symbol 12, it is wrapping 750 mm, and the intermediate wall 13 is located in 2500 mm between both lanes. Furthermore, in the construction part construction process, construction parts (main lane 1a and ramp lane 2a shown at position E in FIG. 2) of both tunnels are constructed.

[Explanation of F position]
The section without the intermediate wall 13 starts from the same position as the E position.

  As shown in the construction drawing at the time of cutting (see FIG. 8A), in the main tunnel construction process, not the permanent segment 4 but the cutable segment 6 (three pieces: angle of the cutting section) at the branch and merge part on the main tunnel 1 side. 39.00 ° or more). In addition, the permanent segment 4 and the thick segment 4a are used except for the branch junction. The permanent tunnel 5 and the thick segment 5a are also used on the lamp tunnel 2 side. Further, in the middle filling material filling step, the outer side of the cutable segment 6 of the main tunnel side branch joint portion is covered with the temporary wall 7, and the middle joint material 8 is filled into the branch joint portion covered with the temporary wall 7. Furthermore, in order to prevent deformation of the main tunnel 1 due to impact during excavation, a plurality of deformation prevention works 15 are provided. The deformation prevention work 15 is removed at the time of construction.

  As shown in the construction drawing at the time of temporary installation (see FIG. 8B), in the natural ground improvement process, the natural ground improving agent 10 is injected around the junction of the main tunnel 1 and the ramp tunnel 2. Further, temporary struts 9 and 9 are erected as reinforcement work in the ramp tunnel 2 and the main tunnel 1 respectively. Further, as a reinforcement work, in order to prevent the lamp tunnel 2 from being deformed, a plurality of deformation prevention works 15 are provided on the lamp tunnel 2 side. Further, a reinforcement work (AGF method) is performed by alternately crossing a plurality of injection-type long steel pipes from the vicinity of the end portions of the thick segments 4a and 5a diagonally upward and diagonally downward.

  Next, in the side surface communication step, the segment of the part where the entered lamp tunnel 2 and the main line tunnel 1 face each other is removed from the lamp side permanent segment 5 and opened, and the buried material 8 and the temporary wall 7 around the opening are removed. After removal, the uncuttable segment 6 remaining in the main tunnel 1 is removed and both tunnels 1 and 2 are communicated with each other on the side surface. As shown in the construction drawing at the time of construction (see FIG. 8 (c)), in the side surface communication step, the main line side segment 4a and the lamp side thick segment 5a are not installed without installing an intermediate wall at the branch junction. The two upper and lower steel beams 17 are inserted into the opposing communication construction parts (interval Ln), and the communication construction parts are joined to form the two upper and lower floor slabs.

Next, the floor slab joining process will be described in detail.
In the communication construction part, since the ramp tunnel 2 is made to enter obliquely with respect to the main tunnel 1, the interval Ln of the communication construction part changes (becomes narrower in the traveling direction) and the shape of the floor slab is not uniform. . However, in the communication construction part, the injection type long steel pipes are crossed and the reinforcement work (AGF method) is carried out, but the floor slab shape is being pushed by the earth water pressure. Requires high accuracy.

Therefore, the floor slab joining process is performed as follows.
First, the steel girder 17 having a width L1 (Ln> L1) smaller than the interval Ln between the communication work portions is manufactured in advance. As shown in FIG. 9, a joint T having a bolt mounting hole is provided at the opposite end of the steel beam 17 and the segment 4a (5a).

  Next, the narrow steel girder 17 is pushed against the soil pressure at the interval Ln of the communication work part, the bolt B is inserted across the bolt mounting holes facing each other, and the steel girder 17 and the segment 4a ( 5a). That is, in this embodiment, the joining member is a bolt B and a nut N. Next, super high strength concrete C such as ductal is placed in the gap between the joints of the steel beam 17 and the segment 4a (5a) to form a floor slab.

  Further, in the construction part construction process, construction parts of both tunnels (main lane 1a and ramp lane 2a shown at position F in FIG. 2) are constructed.

[Explanation of G position]
The same cross section continues for about 100 m as the acceleration / deceleration section.

As shown in the construction drawing during cutting (see Fig. 10 (a)), in the main tunnel construction process,
Instead of the permanent segment 4, a cutable segment 6 (3 sheets: cutting portion angle 47.85 °) is provided at the branch junction at the main tunnel 1 side. In addition, the permanent segment 4 and the thick segment 4a are used except for the branch junction. The permanent tunnel 5 and the thick segment 5a are also used on the lamp tunnel 2 side. Further, in the middle filling material filling step, the outer side of the cutable segment 6 of the main tunnel side branch joint portion is covered with the temporary wall 7, and the middle joint material 8 is filled into the branch joint portion covered with the temporary wall 7. Furthermore, in order to prevent deformation of the main tunnel 1 due to impact during excavation, a plurality of deformation prevention works 15 are provided. The deformation prevention work 15 is removed at the time of construction.

  As shown in the construction drawing at the time of temporary installation (see FIG. 10B), in the ground improvement process, a ground improvement agent is injected around the junction of the main tunnel 1 and the ramp tunnel 2. Further, temporary struts 9 and 9 are erected as reinforcement work in the ramp tunnel 2 and the main tunnel 1 respectively. Further, as a reinforcement work, in order to prevent the lamp tunnel 2 from being deformed, a plurality of deformation prevention works 15 are provided on the lamp tunnel 2 side. Further, reinforcement work (roof shield construction method: see FIG. 16) is carried out by installing roof shields on the upper and lower sides in the vicinity of the ends of the thick segments 4a and 5a. In this case, grooves for installing the roof shield are processed on the upper and lower sides of the thick segments 4a and 5a. Next, in the side surface communication process, the segment of the part where the entered lamp tunnel 2 and the main line tunnel 1 face is removed from the lamp-side permanent segment 5 and opened, and the buried material 8 and the temporary wall 7 around the opening are removed. After removal, the uncuttable segment 6 remaining in the main tunnel 1 is removed and both tunnels 1 and 2 are communicated with each other on the side surface.

  As shown in the construction drawing at the time of construction (see FIG. 10 (c)), in the side surface communication process, the main line side segment 4a and the lamp side thick type segment 5a are formed without installing an intermediate wall at the branch junction. The two upper and lower steel beams 17 are inserted into the opposing communication construction parts (interval Ln), and the communication construction parts are joined to form the two upper and lower floor slabs. Note that the floor slab joining process is the same as in the F position, in which the working conditions of the communication work part are changed by the interval Ln of the communication work part (becomes narrower along the traveling direction) and are pushed by the earth pressure. Therefore, high precision is required for the size of the floor slab shape.

  Therefore, in the floor slab joining process, a steel beam 17 having a width L2 (Ln> L2) smaller in size than the interval Ln of the communication work portion is manufactured in advance, and the width L2 of the communication work portion is resisted against soil water pressure. The narrow steel beam 17 is pushed in, the bolt B is inserted across the bolt mounting holes facing each other, and the steel beam 17 and the segment 4a (5a) are joined by the nut N (see FIG. 8D). Next, super high strength concrete C such as ductal is placed in the gap between the joints of the steel beam 17 and the segment 4a (5a) to form a floor slab.

Further, in the construction part construction process, construction parts of both tunnels (acceleration / deceleration sections of three lanes of the main lane 1a and the ramp lane 2a shown at the position G in FIG. 2) are constructed.

[Explanation of H position]
The position where the cut by the lamp is maximized, and after this, the lamp side shield can be collected.

  As shown in the construction drawing at the time of cutting (see FIG. 11A), in the main tunnel construction process, not the permanent segment 4 but the cutable segment 6 (three pieces: angle of the cutting section) at the branch and merge part on the main tunnel 1 side. 48.92 °) is provided. In addition, the permanent segment 4 and the thick segment 4a are used except for the branch junction. The permanent tunnel 5 and the thick segment 5a are also used on the lamp tunnel 2 side. Further, in the middle filling material filling step, the outer side of the cutable segment 6 of the main tunnel side branch joint portion is covered with the temporary wall 7, and the middle joint material 8 is filled into the branch joint portion covered with the temporary wall 7. Furthermore, in order to prevent deformation of the main tunnel 1 due to impact during excavation, a plurality of deformation prevention works 15 are provided. The deformation prevention work 15 is removed at the time of construction.

  As shown in the construction drawing at the time of temporary installation (see FIG. 11B), in the ground improvement process, a ground improvement agent is injected around the junction of the main tunnel 1 and the ramp tunnel 2. Further, temporary struts 9 and 9 are erected as reinforcement work in the ramp tunnel 2 and the main tunnel 1 respectively. Further, as a reinforcement work, in order to prevent the lamp tunnel 2 from being deformed, a plurality of deformation prevention works 15 are provided on the lamp tunnel 2 side. Further, a reinforcing work (AGF method) is performed by alternately crossing a plurality of injection-type long steel pipes from the vicinity of the end portions of the thick segments 4a and 5a obliquely upward and obliquely downward. Next, in the side surface communication step, the segment of the part where the entered lamp tunnel 2 and the main line tunnel 1 face each other is removed from the lamp side permanent segment 5 and opened, and the buried material 8 and the temporary wall 7 around the opening are removed. After removal, the uncuttable segment 6 remaining in the main tunnel 1 is removed and both tunnels 1 and 2 are communicated with each other on the side surface.

  As shown in the construction drawing at the time of construction (see FIG. 11 (c)), in the side surface communication process, the main line side segment 4a and the lamp side thick type segment 5a are formed without installing an intermediate wall at the branch junction. The two upper and lower steel beams 17 are inserted into the opposing communication construction parts (interval Ln), and the communication construction parts are joined to form the two upper and lower floor slabs. Note that the floor slab joining process is the same as in the F position, in which the working conditions of the communication work part are changed by the interval Ln of the communication work part (becomes narrower along the traveling direction) and are pushed by the earth pressure. Therefore, high precision is required for the size of the floor slab shape.

  Therefore, in the floor slab joining process, a steel beam 17 having a width L3 (Ln> L3) smaller in size than the interval Ln of the communication work part is manufactured in advance, and the width of the connection work part Ln against the soil pressure is reduced. The narrow steel beam 17 is pushed in, the bolt B is inserted between the bolt mounting holes facing each other, and the steel beam 17 and the segment 4a (5a) are joined by the nut N (see FIG. 9). Next, super high strength concrete C such as ductal is placed in the gap between the joints of the steel beam 17 and the segment 4a (5a) to form a floor slab.

  Furthermore, in the construction part construction process, construction parts of both tunnels (acceleration / deceleration sections of three lanes of the main lane 1a and the ramp lane 2a shown at the position H in FIG. 2) are constructed.

[Explanation of I position]
As shown in the construction drawing at the time of cutting (see FIG. 12 (a)), in the main tunnel construction process, not the permanent segment 4 but the cutable segment 6 (two pieces: the angle of the cutting portion) at the branch and merging portion on the main tunnel 1 side. 20.55 °) is provided. Further, in the middle filling material filling step, the middle filling material 8 is filled in the main tunnel.

  As shown in the construction drawing at the time of temporary installation (see FIG. 12B), in the natural ground improvement process, the natural ground improving agent is injected from the ramp tunnel 2 to the vicinity of the junction. Further, in the side surface communication process, the temporary support column 9 is erected, and the segment of the ramp tunnel 2 that has entered the portion that has entered the main tunnel 1 is removed from the ramp-side permanent segment 5 and is opened. The embedded material 8 in the tunnel 1 is removed, and the remaining cuttable segments 6 of the main tunnel 1 are removed.

  As shown in the construction drawing at the time of construction (see FIG. 12C), the permanent segments 4 and 5 are connected in the side surface communication step. In FIG. 12C, 11 indicates the building limit line of the main tunnel 1 based on the road structure ordinance, and 12 indicates the building limit line of the ramp tunnel 2. Further, in the construction part construction step, construction parts of both tunnels (main lane 1a shown at position I in FIG. 2) are constructed.

[Explanation of J position]
In the H to I section where the scale of the widening is small, it is also possible to adopt the partial widening method (M-ESS method) by the shield machine 31 of the main tunnel 1 shown in FIG. That is, as shown in the construction drawing at the time of cutting (see FIG. 13 (a)), in the main tunnel construction process, the side portion is widened by the side cutter 18, and the ground improvement agent 10 is injected into the widened portion excavated. .

  Next, as shown in the construction drawing at the time of temporary installation (see FIG. 13B), an extruded segment 19 to be installed in the widened portion is prepared, and the extruded segment 19 is pushed out by the segment pusher 20 that pushes in the widening direction. The ground improvement agent 10 injected into the portion is collected.

  Next, as shown in the construction drawing at the time of construction (see FIG. 13C), in the construction part construction process, the construction part of the main tunnel 1 (main lane 1a and ramp lane 2a shown at position J in FIG. 2) To construct. In FIG. 13C, 11 indicates the building limit line of the main tunnel 1 based on the road structure ordinance, and 12 indicates the building limit line of the ramp tunnel 2.

  In the above-described embodiment, the case has been described in which the following tunnel (ramp tunnel) is obliquely entered with respect to the preceding tunnel (main line tunnel) and the succeeding tunnel (ramp tunnel) is merged with the preceding tunnel (main line tunnel). However, the present invention also includes a case in which the construction order is changed, the lamp tunnel is advanced, and the main line side shield machine advances into the preceding lamp tunnel.

  INDUSTRIAL APPLICABILITY The present invention can be used for tunnel construction in which a succeeding tunnel is obliquely entered with respect to a preceding tunnel and the succeeding tunnel is joined to the preceding tunnel, more specifically, when it is desired to easily cope with various joining angles.

It is a perspective view which shows the outline of the branch merge part construction method of the shield tunnel of this invention. It is a top view of the main line 1a and the lamp | ramp 2a constructed in the branch merge part of the main line tunnel 1 and the ramp tunnel 2. FIG. It is a construction process figure used according to the situation of the position of A of FIG. It is a construction process figure used according to the situation of the position of B of FIG. It is a construction process figure used according to the situation of the position of C of FIG. It is a construction process figure used according to the situation of the position of D of Drawing 1. It is a construction process figure used according to the condition of the position of E of FIG. It is a construction process figure used according to the situation of the position of F of FIG. It is an expansion perspective view of the communication construction part of FIG.8 (c). It is a construction process figure used according to the condition of the position of G of FIG. It is a construction process figure used according to the situation of the position of H of FIG. It is a construction process figure used according to the situation of the position of I of FIG. It is a construction process figure used according to the situation of the position of J of FIG. It is explanatory drawing of the center distance between tunnels. It is a graph which shows the relationship between the center distance between tunnels, and a cutting part angle. It is explanatory drawing of the work space for bit exchange. It is explanatory drawing of a roof shield construction method. It is construction explanatory drawing of the widened part by the shield machine of the main line tunnel.

Explanation of symbols

1 Main tunnel 2 Lamp tunnel 3 Shield machine (Ramp side)
4 Permanent segment (main line side)
4a Thick mold segment (main line side)
5 Permanent segment (lamp side)
5a Thick mold segment (lamp side)
6 Cutable segment 7 Temporary wall 8 Filling material 9 Temporary support 10 Ground mountain improving agent 11 Building limit line (Main line side)
12 Building limit line (lamp side)
13 Intermediate wall 14 Hairpin 15 Deformation prevention work 16 Steel pipe 17 Steel girder (floor slab)
B Bolt N Nut T Joint C Super high strength concrete

Claims (11)

Used when the succeeding tunnel is obliquely entered with respect to the preceding tunnel and the succeeding tunnel is merged with the preceding tunnel, or when the succeeding tunnel is obliquely exited from the preceding tunnel and the succeeding tunnel is branched from the preceding tunnel A method for constructing a branching junction of a shield tunnel,
Before joining the early and succeeding tunnels and at the early stage of joining,
A filling material filling step of filling the filling material in the branching junction on the preceding tunnel side;
Compared to the segment that is permanently installed in the preceding tunnel, the preceding tunnel construction process in which a cutable segment that can be cut by the trailing shield machine is provided in the branching junction on the preceding tunnel side instead of the permanent segment,
The following tunnel entering into the preceding tunnel obliquely entering the preceding tunnel by excavating while constructing the succeeding tunnel by the following shield excavator and cutting the cutable segment on the buried material and the preceding tunnel side. Construction process,
A natural ground improvement process for improving the natural ground around the branch and junction part from both tunnels,
Remove the permanent segment of the portion where the following incoming tunnel and the preceding tunnel face each other, open the opposite portions of both tunnels, remove the embedding material around this opening, and without cutting the preceding tunnel A side surface communication step of removing the remaining cuttable segments and communicating opposite side surfaces of the preceding tunnel side and the subsequent tunnel side; and
An architectural part construction process for constructing the architectural parts of both tunnels ,
A method for constructing a branching / merging portion of a shield tunnel, characterized in that an injection pipe used for water stoppage measures in a side surface communication step is embedded in the cuttable segment in advance .   In the filling material filling step, the branch and merge portion on the preceding tunnel side is temporarily set according to the relationship between the distance between the tunnel centers and the cutting portion angle when the trailing shield machine enters the preceding tunnel. The method for constructing a branching / merging part of a shield tunnel according to claim 1, wherein the branching / merging part covered with a wall and filled with a temporary wall is filled with an embedded material.   In the preceding tunnel construction process, according to the relationship between the distance between the center of the tunnel and the cutting portion angle when the trailing shield machine enters the preceding tunnel, the preceding tunnel is disposed at the branching junction on the preceding tunnel side. The method for constructing a branching / merging portion of a shield tunnel according to claim 1 or 2, wherein a segment capable of being cut is determined. The cuttable segments branching portion of the shield tunnel according to any one of claims 1 to 3, characterized in that it is a new material concrete member comprising a diameter of carbon fiber reinforced material and light-weight aggregate Construction method. The cuttable segment shield tunnel branching unit construction method according to any one of claims 1 to 4, characterized by applying roughening roughened cutting surface on which the shield machine is cutting. A position detecting means is provided at the branching junction on the preceding tunnel side,
The said subsequent tunnel entrance construction process WHEREIN: The said subsequent shield excavation machine approachs into the said preceding tunnel based on the positional information on the said position detection means, The any one of Claims 1-5 characterized by the above-mentioned. To construct a junction and junction of a shield tunnel. In the natural ground improvement process, depending on the relationship between the distance between the center of the tunnel and the cutting portion angle when the trailing shield machine enters the preceding tunnel, in addition to natural ground improvement by chemical injection, both tunnels Either a construction that reinforces the natural ground using a shearing girder that passes the shape steel in between, a construction that reinforces the natural ground by alternately intersecting press-fit long steel pipes, or a construction that reinforces the natural ground using a roof shield shield tunnel branching unit construction method according to any one of claims 1 to 6, characterized in that the reinforcement work with or. In the side surface communication step, depending on the relationship between the distance between the center of the tunnel and the cutting portion angle when the trailing shield machine enters the preceding tunnel, a step of installing an intermediate wall at the branch / merging portion The method for constructing a branching / merging portion of a shield tunnel according to any one of claims 1 to 7 , further comprising: In the side surface communication step, a thick segment is used in addition to the side surface communication portion, depending on the relationship between the distance between the tunnel centers and the cutting portion angle when the trailing shield machine enters the preceding tunnel. The method further comprises the step of joining the upper and lower two opposing thick segments on the preceding tunnel side and the succeeding tunnel side with steel beams to form two upper and lower floor slabs. shield tunnel branching unit construction method according to any one of 1-7. The step of joining the thick segments with steel beams to form two upper and lower floor slabs is a communication construction part in which the thick segments on the preceding tunnel side and the thick segments on the subsequent tunnel side face each other. The steel girder having a width Li (Ln> Li) smaller than the interval Ln of the communication work portion is disposed, and the steel girder and the thick segment are joined by a joining member, and the steel girder and 10. The method for constructing a branching junction of shield tunnels according to claim 9 , wherein ultra-high-strength concrete is cast in a gap at a joint portion with the thick segment to form the floor slab. In the filling material filling step, a space not filled with the filling material is provided in advance by installing a cylindrical member between the cuttable segment and the temporary wall, and the trailing shield digging is performed by this space. The method for constructing a branching / merging portion of a shield tunnel according to claim 2 , further comprising a work space construction step for exchanging bits for exchanging beats of the machine.

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