JP4746602B2 - Segment connection structure - Google Patents

Description

  The present invention relates to a connecting structure of segments used when connecting adjacent segments in the circumferential direction to form a tunnel, and particularly when forming an outer periphery of a tunnel branching junction where two tunnels branch or merge. The present invention relates to a suitable segment connection structure.

  Conventionally, the so-called shield tunnel constructed based on the shield method is mainly a tunnel with a circular cross section that is structurally stable. However, as the development of urban underground road networks in recent years has progressed, the number of cases where a tunnel branching / merging section where two tunnels branch or merge is required increases. In particular, this tunnel branching junction is frequently used in the case where one lamp tunnel is connected to one main tunnel.

  Conventionally, the main part of the tunnel junction is the open-cut method of construction where the ground is dug down from the ground surface. This excavation method has the advantage that the earth and water pressure acting on the tunnel during construction can be made relatively small in order to remove the ground between the tunnels.

  However, in this excavation method, the construction location of the tunnel branching junction is limited to a place where excavation work from the ground surface can be performed. That is, in the case of performing construction based on the open-cut method, there has been a problem that a site for constructing the tunnel branch junction must be secured. In addition, when such a tunnel branch and junction must be constructed in a deep underground, the excavation labor for such excavation becomes excessive, and the construction cost including groundwater countermeasures is expensive.

  For this reason, from the viewpoint of land saving and suitable for deep tunnel construction, the construction method of the tunnel junction / merging section in recent years is shifting from the above-mentioned open-cut method to the so-called non-cut-open method.

  As shown in FIG. 20, this non-opening method is a tunnel branching junction for connecting the main tunnel 202 and the ramp tunnel 203 by using a horizontal hole 201 opened in the ground without excavating the ground from the ground surface. Build up. At this time, since an overload from the ground 204 above the tunnels 202 and 203 acts, earth and water pressure acting on each of the tunnels 202 and 203 is greatly generated at the time of construction of the tunnel branching junction. In addition, the method of constructing a tunnel branching / merging portion based on this non-open cutting method required a high-strength linking structure that can reliably connect segments to each other in a limited space.

  FIG. 21A shows a completed view of the tunnel branching / merging portion 206 for branching or joining the main tunnel 202 and the ramp tunnel 203 constructed based on this non-cutting method. When this tunnel branching / merging portion 206 is applied to a deep tunnel in which the earth covering in the ground 204 exceeds 50 m, a large groundwater pressure of 0.5 MPa or more acts in addition to the earth pressure. FIG. 21B shows the distribution of the bending moment acting on the tunnel branching junction 206. The tunnel branching / merging portion 206 is configured as a horizontally long tunnel cross section including the main tunnel 202 and the lamp tunnel 203, and a large positive bend occurs in the horizontally long portion. This positive bending acts in such a way that a tensile force is applied to the inner surface of the tunnel. For this reason, in the tunnel branching junction 206, it is necessary to establish a high-strength, high-rigidity inter-segment connection structure capable of resisting such a large positive bending, and further, between the segments having high water-stopping performance. There was also a need for a connected structure.

  Conventionally, there has been proposed a method of configuring the tunnel branching / merging portion 206 with segments made of reinforced concrete (RC) members. However, in order to construct a highly rigid segment structure with this RC member, the girder height of the RC member has to be about 2 to 3 m, and there is a possibility that the building limit in the tunnel interior will be violated.

  Conventionally, for example, a connection structure 119 of the main tunnel 101 and the lamp tunnel 103 as shown in FIG. 22 has been proposed (see, for example, Patent Document 1). Although the interval between the main tunnel 101 and the ramp tunnel 103 changes gradually, the segment 125 constituting the main tunnel 101 and the segment 131 constituting the ramp tunnel 103 are connected via the connection structure 119. Will do.

  FIG. 23A shows a horizontal sectional view of a portion A of the joint structure 119 in FIG. 22, and FIG. 23B shows a horizontal sectional view of a portion B of the joint structure 119.

  In this connection structure 119, the connection structure 119 is installed between the end face 126 of the segment 125 of the main tunnel 101 and the end face 128 of the segment 131 of the lamp tunnel 103. The connection structure 119 includes a piece 127 whose one end is fixed to the end surface 126 of the segment 125, and the piece 127 is fixed on the extension of the joint surface between the rings of the segment 125. Further, this piece material 127 is obtained by fixing joint plates 133 to both ends of an H-shaped steel, for example.

Incidentally, in the portion A shown in FIG. 23A, the interval between the main tunnel 101 and the lamp tunnel 103 is constant, and therefore a rectangular piece 127 is interposed. On the other hand, in the portion B shown in FIG. 23B, the interval between the main tunnel 101 and the lamp tunnel 103 is enlarged or reduced, so that the top material 127 is formed in a trapezoidal shape. Then, an error absorbing plate 141 is sandwiched between the joint plate 133 of the top member 127 and the joint plate of the H-shaped steel 129.
JP-A-2006-283285

  By the way, the connecting structure of the shield tunnel segments constructed based on the shield method often causes, for example, assembly construction errors when controlling the attitude of the shield machine or assembling the segment ring. This assembly construction error is often managed within a maximum range of 40 to 50 mm with respect to the tunnel axial direction and the tunnel circumferential direction. In particular, when two tunnels are branched or merged, an assembly error has already occurred in both the main tunnel and the ramp tunnel. For this reason, it is necessary to absorb the assembly construction errors of both the main tunnel and the lamp tunnel in the segment constituting the tunnel branching / merging portion that branches and joins each other.

  However, in the conventional technology disclosed in Patent Document 1 described above, in order to absorb such assembling errors, the H-section steel 129 and the piece material 127 as connecting members are set to predetermined dimensions necessary for on-site connection. It is necessary to sandwich the error absorbing plate 141 in order to cut and further align the members at the time of connection. In particular, in the disclosed technique of Patent Document 1, in a segment constituting a tunnel branching / merging portion actually disposed at a site, a detailed dimension of an assembly construction error is investigated based on a field survey, and a coma commensurate with this is investigated. It is necessary to manufacture the material 127 and the like, carry it in the field, and fix it on the extension of the joint surface between the rings of the segment 125.

  That is, in the disclosed technique of Patent Document 1, it is necessary to eliminate the earth and sand in the vicinity of this tunnel branch and junction, and to take a long period of time for on-site surveying and production of the top piece 127 and the like, and during that time the construction must be interrupted. was there. Therefore, it has not been possible to meet the demand for shortening the construction period that is increasing in recent years. Further, since the shear transmission performance is poor at the interface sandwiching the error absorbing plate 141, there is a high possibility that inconvenience will occur from the structural mechanical viewpoint.

  In particular, when the main tunnel and the ramp tunnel are configured by the segment having the main beam orthogonal to the tunnel axis direction, in the section in which the interval between the main tunnel and the ramp tunnel is increased or reduced as shown in the above-described part B. As shown in FIG. 24, the main beam 151 extended from the main tunnel side and the main beam 152 extended from the ramp tunnel side intersect at different angles. In order to eliminate such an angle deviation between the main girders 151 and 152, the step of manufacturing the above-described piece of material or the like on the basis of the field survey result is eliminated, and if the combination is made, the above angle There was also a need to shorten the construction period by adopting a configuration in which the segments can be firmly connected while eliminating the deviation.

  Therefore, the present invention has been devised in view of the above-described problems, and the object of the present invention is in a connecting structure of segments constituting the outer periphery of a tunnel branching junction where two tunnels branch or merge. An object of the present invention is to provide a segment connecting structure that can absorb assembly construction errors of both tunnels while shortening the construction period.

  In order to solve the above-described problem, a segment connection structure according to the present invention is a tunnel segment connection structure applied when connecting segments having a plurality of main beams orthogonal to the tunnel axis direction to each other. The main girder of each segment is connected to another main girder adjacent in the tunnel axis direction via an end plate, and a support plate is provided at the tip, and between the end plate and the support plate, The stress transmission girder is provided in the tunnel axis direction, the main girder of the other segment is loosely fitted between the main girder of one segment with a gap capable of absorbing the construction error, and the end plate between the main girder of the one segment. Is faced to the bearing plate at the tip of the main beam of the other segment, and the stress transmission beam in the one segment is the main beam of the other segment. The gap between the main girder of one segment and the main girder of the other segment which is located on the inner surface of the tunnel and / or the outer surface of the tunnel and is loosely fitted to each other is filled with a filler. And

  In the present invention having the above-described configuration, the main beam of the other segment is loosely fitted between the main beams of one segment, so that it is possible to absorb assembly construction errors of both of the two tunnels constituting the tunnel branching junction. It becomes possible.

  Further, in the present invention having the above-described configuration, it is possible to transmit a loaded axial force, bending moment and shearing force via a stress transmission girder, an end plate, etc., so that the stress transmission performance can be improved. It becomes possible.

  Furthermore, in the present invention, even when segments are connected to each other, the step of manufacturing the coma material and the like as in the prior art based on the on-site survey results is eliminated, and if assembled, the construction errors are eliminated immediately while the construction errors are eliminated. It is possible to firmly connect these segments. For this reason, it becomes possible to shorten the construction period.

  In particular, in the present invention, it is possible to transmit a bending moment and a shearing force with a simple stress transmission structure. Incidentally, the ability to transmit bending moment and shearing force is about 70% of the main girder strength.

  Hereinafter, as a best mode for carrying out the present invention, a connection structure of segments constituting the outer periphery of a tunnel branching / merging portion where two tunnels branch or join will be described in detail with reference to the drawings.

  In the tunnel branching / merging unit 1 to which the segment connection structure to which the present invention is applied is applied, for example, as shown in FIG. 1, the main tunnel 11 and the ramp tunnel 12 merge and connect to one tunnel 13. In other words, it is a portion that branches from one tunnel 13 to the main tunnel 11 and the ramp tunnel 12. Incidentally, FIG. 1A shows a configuration from one tunnel 13 to two branches from the main tunnel 11 and the ramp tunnel 12, and FIG. 1B shows the configuration shown in FIG. FIG. 1C is a cross-sectional view taken along the line BB, FIG. 1D is a cross-sectional view taken along the line CC, and FIG. 1E is a cross-sectional view taken along the line DD.

  Here, the case where the main tunnel 11 and the ramp tunnel 12 merge and connect to one tunnel 13 will be described as an example. The main tunnel 11 and the ramp tunnel 12 are embedded in the ground in a form in which a circular cylindrical segment ring is continued in the tunnel axis direction, as shown in the DD cross-sectional view. Here, a target section k1 shown in FIG. 1A is a section where the main tunnel 11 and the ramp tunnel 12 merge. When entering the target section k1 and joining the tunnels 11 and 12 together, for example, as shown in the CC cross-sectional view (FIG. 1 (d)), the remaining part of the segment constituting the outer periphery of the main tunnel 11 A segment is newly provided and a partition wall 15 is further provided between 11a and the remaining portion 12a of the segment that has formed the outer periphery of the lamp tunnel 12. A region where the newly established segments are continuous is referred to as a new portion 14.

  In this target section k1, the central axes of the main tunnel 11 and the ramp tunnel 12 gradually approach each other, and the length of the new section 14 is accordingly shown in the BB sectional view (FIG. 1 (c)). And the partition wall 15 is also removed. And finally it connects with the one circular cylindrical tunnel 13 as shown by AA sectional drawing (FIG.1 (b)), and the object area k1 will be complete | finished.

  The connecting structure of the segments to which the present invention is applied is connected in the circumferential direction of the segments adjacent to each other between the segment constituting the newly installed portion 14 and the remaining portions 11a and 12a of the segments constituting the main line tunnel 11 and the lamp tunnel 12. Used when

  FIG. 2 illustrates a connection structure between the remaining portions 11 a and 12 a and the new portion 14. Each segment 2 is a synthetic segment in which the steel shell is filled with concrete. In addition, the segment 2 is located at the upper end and the lower end of the remaining portions 11 a and 12 a and is a segment located at a connection location with the newly installed portion 14. That is, the connecting structure is configured by connecting the segment 2 extended from the newly installed portion 14 and the segment 2 extended from the remaining portions 11a and 12a to each other.

  3 and 4 show an enlarged perspective view of the segment 2. The segment 2 shown in FIGS. 3 and 4 is an example of the segment 2 constituting the portion H in FIG. 2. FIG. 3 is the segment 2 extended from the newly installed portion 14, and FIG. The segment 2 extended from the parts 11a and 12a is shown. However, since the segments 2 constituting the other I, J, and K portions are also embodied by the same configuration, FIG. 3 constitutes the segment 2 extended from the remaining portions 11a and 12a, and FIG. However, the segment 2 extended from the new installation part 14 may be comprised. Further, in the lower J and K portions, normal RC segments may be used.

  The segment 2 includes a main girder 22 orthogonal to the axial direction of the tunnel, a support plate 24 provided at the tip of the main girder 22, an end plate 25 connecting the main girder 22 adjacent in the tunnel axial direction, and an end plate. 25 and two stress transmission girders 26 provided in the middle of the bearing plate 24.

  In the form shown in FIG. 3, the main girder 22 is composed of two pieces. In the form shown in FIG. 4, the main girder 22 is arranged between the outer main girder formed at both ends of the tunnel axis direction and the outer main girder. In addition, although the case where it is constituted by three middle main digits is shown, it is not limited to this, and it may be constituted by any number. Usually, the main girder 22 is composed of two to four. Each main girder 22 is formed of a steel plate that has been formed and processed to have the same shape. The main girder 22 is set so that the girder height becomes smaller in the girder height reduction section k2 at the front end. On the rear end side of the digit height reduction section k2, the digit height is set large. The main girder 22 has a plate thickness of about 30 to 100 mm. Incidentally, an opening hole 27 may be formed in the main beam 22 at a predetermined interval.

  The bearing plate 24 is fixed to the main girder by means such as welding, and the plate thickness is about 30 to 100 mm. A stiffening plate 28 is attached to the side surface of the main girder 22 from the bearing plate 24 toward the circumferential direction of the tunnel. The plate thickness of the stiffening plate 28 is also about 30 to 100 mm, and is fixed to the main girder 22 and the bearing plate 24 by welding or the like.

  The end plate 25 is disposed so as to extend in a direction perpendicular to the main beam 22, in other words, in the tunnel axis direction, and has a plate thickness of about 30 to 100 mm. Further, the end plate 25 is disposed so as to bridge between the main girders 22, and is fixed to the end plate 25 by welding or the like. A stiffening plate 29 is attached to the side surface of the main girder 22 from the end plate 25 toward the rear end side. The stiffening plate 29 has a thickness of about 30 to 100 mm and is fixed to the main girder 22 and the bearing plate 24 by welding or the like in directions orthogonal to each other.

  The stress transmission girders 26a and 26b are made of an H-shaped steel made up of upper and lower flanges and a web. Incidentally, the stress transmission girders 26a and 26b may be arranged between the end plate 25 and the bearing plate 24, but may be arranged on the rear end side of the girder height reduction section k2. Required. The stress transmission girders 26a and 26b are arranged so as to erection the side face of the main girder 22, and are fixed by means such as welding. The stress transmission girders 26a and 26b may be formed in a cross-sectional H shape or a cross-sectional box shape excellent in bending rigidity, but may further be formed in a cross-sectional T shape, C shape, or L shape. Further, the stress transmission girders 26a and 26b are not limited to the case where the stress transmission girders 26a and 26b are provided over the two, and it is sufficient that at least one is provided.

  When connecting the segments 2 having the above-described configuration, the main beam 22 of the other segment 2 has a gap that can absorb construction errors between the main beams 22 that constitute one segment 2 to be connected to each other. This is done by fitting. Specifically, as shown in FIGS. 5 and 6, there is play in a state where a gap is formed between the main beam 22 constituting one segment 2 and the main beam 22 of the other segment 2. It is fitted in the state. At this time, it is necessary to form a gap that can move between the main beam 22 constituting one segment 2 and the main beam 22 of the other segment 2. The reason for providing this gap is to absorb mutual construction errors.

  In the example of FIGS. 5 and 6, the end plate 25 between the main beams 22 of one segment 2 faces the bearing plate 24 at the tip of the main beam 22 of the other segment 2. At this time, adjustment is made so that a gap is formed between the end plate 25 and the bearing plate 24. Similarly, the main beam 22 of one segment 2 and the main beam 22 of the other segment 2 are adjusted so that a gap is formed between them. By forming such a gap, the segments 2 can move horizontally or vertically between the tunnel axis direction, the tunnel circumferential direction, and further from the inner sky surface side to the ground mountain side. In particular, since such a gap is formed, the main girder 22 constituting one segment 2 and the main girder 22 constituting the other segment 2 are arranged at an angle to each other. Is also possible.

  Note that a filler 41 is filled in the gap between the main girder 22 and the end plate 25 and the bearing plate 24 that are loosely fitted to each other. As the material of the filler 41, for example, a high-strength solidifying material such as high-strength mortar or concrete is applied. Incidentally, in order to improve the filling property, for example, a high flow type with a slump flow of 50 cm or more to which a fluidizing agent such as an AE (Air Entrain) water reducing agent is added may be applied. When filling the filling material 41, for example, a mold is installed on site to fill the filling material 41.

  Incidentally, when the segments 2 are connected, the bearing plate 24 formed at the tip of the main girder 22 and the end plate 25 in the opposite segment 2 face each other through a gap, and the gap Since the filler 41 is filled, the bearing plate 24 and the end plate 25 face each other through the filler 41. In the girder height reduction section k2, the stress transmission girders 26a and 26b and the main girder 22 are close to or in contact with each other in the vertical direction.

  When the axial force D is transmitted through the main girder 22 in the direction as shown in FIG. 7A, for example, in the segments 2 connected in this way, the bearing plate 24 and the end plate 25 are connected to each other. Since the filler 41 is interposed in the gap, the axial force D is applied to the bearing plate 24 (end plate 25), the filler 41, and the end plate 25 (bearing plate 24). It is possible to transmit in this order. The transmitted axial force is transmitted through the main beam 22 of the other segment 2.

  In particular, when the stiffening plates 28 and 29 described above are formed, the axial force D is transmitted in the order of the support plate 24 (end plate 25), the filler 41, and the end plate 25 (support plate 24). Therefore, the rigidity of the bearing plate 24 and the end plate 25 can be supplemented.

  Further, by providing the opening hole 27 for the main girder 22, it is possible to transmit a force from the opening hole 27 via the filler 41, and it is possible to further improve the transmission performance of the axial force. It becomes.

  In addition, when a bending moment E is applied in the direction as shown in FIG. 7B, for example, in the segments 2 connected as described above, a couple is formed and the transmission force F based on this is loaded. become. Similarly, when a shearing force G is applied, a transmission force F based thereon is applied.

  However, in the present invention, when the segments 2 are connected, the stress transmission girders 26a and 26b and the main girder 22 are close to or in contact with each other in the vertical direction in the girder height reduction section k2. The transmission force F transmitted from the natural mountain side or from the natural mountain side to the inner sky surface side can be transmitted in the vertical direction through the stress transmission beams 26 arranged in the vertical direction. Further, by providing the opening hole 27 in the main girder 22, it is possible to transmit a force from the opening hole 27 through the filler 41, and it is possible to further improve the bending stress transmission performance. It becomes.

  In particular, in the present invention, since the distance between the stress transmission girder 26 of one segment 2 and the stress transmission girder 26 of the other segment 2 is separated to some extent, the transmission force F based on the bending moment E and the shearing force G is used. Can be transmitted more effectively.

  The segment connection structure to which the present invention is applied can also be applied to a form as shown in FIG. 8, for example.

  In the embodiment shown in FIG. 8A, the same components and members as those in the embodiment shown in FIGS.

  In this segment 2, vertical ribs 30 are provided at a predetermined interval from the natural mountain side to the inner sky surface side. In the segment 2, ring bolt holes 31 are provided between the vertical ribs 30 in the tunnel axis direction corresponding to the depth direction in the drawing. The ring bolt hole 31 is used when connecting to another segment adjacent in the tunnel axial direction. In addition, the segment 2 is further provided with a joint plate 32 in which segment bolt holes (not shown) are formed so as to be connectable with other segments in the remaining portion 11a adjacent in the circumferential direction. Further, the gap between the bearing plate 24 and the end plate 25 and the gap between the main girder 22 and the stress transmission girder 26 are set as a margin for construction.

  The segment connection structure to which the present invention is applied can also be applied to a form as shown in FIG.

  In the configuration shown in FIG. 8B, the same components and members as those in the configuration shown in FIG. 8A described above are denoted by the same reference numerals, and the following description is omitted. The support plate 24 and the stiffening plate 28 are provided in two stages. With such a structure, the performance of transmitting the axial force D is improved. In addition to the transmission between the bearing plate 24 and the end plate 25, the axial force D is transmitted in the order of the bearing plate 24 (stress transmission beam 26a), the filler 41, and the stress transmission beam 26a (loading plate 24). Is possible. The transmitted axial force is transmitted through the main beam 22 of the other segment 2.

  The segment connection structure to which the present invention is applied can also be applied to a form as shown in FIG. 9, for example.

  In the form shown in FIG. 9, the same components and members as those in the form shown in FIG.

  The stress transmission girder 26 is provided on the bottom surface of the main girder 22. Even in the case where the stress transmission girder 26 is provided outside the main girder 22 as described above, the same effect can be obtained. However, the configuration in which the stress transmission girder 26 is arranged so as to be within the girder height of the main girder 22 as in the form shown in FIG.

  For example, as shown in FIG. 10, the segment connection structure to which the present invention is applied may be configured to form a rising portion 40 constituting a part of the new portion 14 for the segment 3 extended from the new portion 14. Good. The vertical rib 30 and the ring bolt hole 31 may also be provided in the rising portion 40.

  FIG. 11 shows an example in which the stress transmission girders 26 are provided on the natural ground side. This makes it possible to transmit the transmission force between the stress transmission girder 26 and the main girder 22 provided on the natural ground side, particularly when a bending moment E in the direction shown in the figure is applied. This is advantageous.

  FIG. 12 shows an example in which the stress transmission girders 26 are provided on both the natural ground side and the inner sky surface side, respectively. As a result, the stress transmission girder 26 provided on both the natural ground side and the inner sky surface side can transmit the transmission force to and from the main girder 22 regardless of the bending moment E. This is advantageous.

  Next, the construction method of the segment connection structure to which the present invention is applied will be described in detail with reference to the drawings.

  First, with respect to the main tunnel 11 and the ramp tunnel 12 constituting the tunnel branching / merging portion, a temporary segment 4 as shown in FIG. 13 is prepared at a portion corresponding to a connecting portion between the remaining portions 11a, 12a and the newly installed portion 14. . In the temporary segment 4, vertical ribs 51 are provided at predetermined intervals from the natural mountain side to the inner sky surface side. In the temporary segment 4, ring bolt holes 53 are respectively provided between the vertical ribs 51 in the tunnel axis direction corresponding to the depth direction of the paper surface in the figure, and the skin plate 52 is provided on the ground mountain side to prevent intrusion of earth and sand. It is arranged. The ring bolt hole 53 is used when connecting to another segment adjacent in the tunnel axis direction. Further, the temporary segment 4 is further provided with a joint plate 54 in which a segment bolt hole (not shown) for enabling connection with other segments in the removal portion 5 adjacent in the circumferential direction is formed. Further, the temporary segment 4 is provided with an end plate 25 on the rear end side, and a stiffening plate 29 is further fixed thereto.

  At this stage, in the main tunnel 11 and the ramp tunnel 12, the segments constituting the removal portion 5 to be removed in the future remain connected.

  Next, after the ground around the tunnel is frozen and reinforced, the soil between the main tunnel 11 and the ramp tunnel 12 is excavated.

  Next, the vertical ribs and skin plate of the temporary segment 4 are removed and the segment 2 is formed. You may make it remove the segment which comprises the removal part 5 before and after this stage.

  Next, as shown in FIG. At this time, the segment 2 extended from the remaining portions 11a and 12a and the segment 2 extended from the new portion 14 are loosely fitted to each other. At this time, position adjustment is performed so as to absorb mutual construction errors. By the way, when constructing the segment of this newly installed part 14, it is executed using heavy equipment, but it may be relatively bright how much construction error has occurred at this stage. For this reason, it is desirable to perform the alignment of the segments 2 with each other at that stage.

  Next, as shown in FIG. 16A, a filler 41 is filled in the gaps between the main beam 22, the bearing plate 24, and the end plate 25 of the segments 2 to be connected to each other. As described above, the construction errors are absorbed between the segments 2, and in this state, the filler 41 is filled to fix them. By filling the filler 41 without gaps, it is possible to ensure water-stopping.

  FIG. 16 (b) shows an example in which the steel member is covered with reinforced concrete 121 in the newly installed portion 14 to form a steel reinforced concrete structure cross section. This configuration can be completed by completing the on-site assembly of the steel members constituting the newly installed portion 14 and installing a reinforcing bar and a mold (not shown) around it and filling the mold with concrete. By the structure covered with the reinforced concrete 121, the member yield strength and rigidity of the newly-installed portion 14 are increased, and it is possible to obtain effects such as deformation suppression of the tunnel branching junction cross section. In addition, since the structure covered with this reinforced concrete 121 is not concerned with the structure of a connection part, the performance of the connection structure made into the effect of this invention is not influenced.

  FIG. 17 shows an example in which the segments 2 adjacent to each other in the tunnel axis direction are connected in the tunnel axis direction. In this example, each segment 2 is composed of three main girders 22, and the main girders located at the end portions in the axial direction of each segment 2 are joined to each other to establish the axial connection. The joined main beams 22 are loosely fitted between the main beams 22 of the other segment 2.

  In the construction method of the segment connection structure to which the present invention is applied as described above, the step of manufacturing the top material, etc. as in the prior art each time based on the field survey result is eliminated, and the construction error is solved immediately if it is assembled to the last. It becomes possible to strongly connect each other's segments. For this reason, it becomes possible to shorten the construction period. Further, since it is not necessary to dispose the error absorbing plate, the construction period can be further shortened.

  By the way, the segment connection structure to which the present invention is applied is the case where the segments constituting the newly installed portion 14 and the remaining portions 11a and 12a of the segments constituting the main line tunnel 11 and the lamp tunnel 12 are connected in the circumferential direction. For example, as shown in FIG. 18, the present invention can also be applied between segments constituting the newly installed portion 14.

In the form shown in FIG. 18, the segment 2 is provided in the new part 14 extended from the ramp tunnel 12 side, and the segment 2 is provided in the new part 14 extended from the main tunnel 11 side. And these segments 2 are connected similarly to the method mentioned above. At this time, it is desirable to provide one connection structure of the segments 2 near the center of the new portion 14. The reason for this is that the main girder 22 constituting the segment of the newly installed portion 14 extended from the ramp tunnel 12 side and the main girder 22 constituting the segment of the newly installed portion 14 extended from the main tunnel 11 side are in particular the main line. In the section where the distance between the tunnel 11 and the ramp tunnel 12 is enlarged or reduced, the two intersect each other at different angles. In order to eliminate such a deviation of the angle between the main girders 22, the present invention capable of firmly connecting the segments while eliminating the deviation of the angle is provided near the center of the newly installed portion 14. This is because it becomes possible.

  The specifications of the tunnel junction 1 are as follows: the outer diameter of the main tunnel 11 is 12.3 m, the outer diameter of the ramp tunnel 12 is 9.9 m, the distance between the centers of both tunnels 11 and 12 is 9.4 m, segment 2 The design cross-sectional force of the main girder 22 that constitutes is an axial force of 8391 kN and a bending of 1800 kNm.

  When the present invention is applied, the girder height of the segments of the main tunnel 11 and the ramp tunnel 12 is 700 mm and the girder height of the connecting member is 600 mm, whereas when the connecting member has an RC structure, the main tunnel 11 The height of the segment of the lamp tunnel 12 is 700 mm, and the height of the connecting member is 4000 mm.

  Further, the gaps in the segments 2 and 3 are set with the sizes shown in FIGS. 19 (a) and 19 (b). In other words, in the coordinate system shown in the drawing, +225 mm and −100 mm can be moved in the X direction, ± 50 mm can be moved in the Z direction, and ± 50 mm can be moved in the depth direction (Y direction). Further, in FIG. 16C, the angle θy can be varied by ± 2.6 °.

It is a figure which shows the tunnel branch merge part to which the connection structure of the segment to which this invention is applied is applied. It is the figure which illustrated the connection structure of the segment in a remaining part, and the segment in a new installation part. It is an expansion perspective view of a segment to which the present invention is applied. It is another expansion perspective view of the segment to which this invention is applied. It is a perspective view which shows the example connected by making a segment fit loosely. It is a top view which shows the example connected by making a segment fit loosely. It is a figure for demonstrating the transmission mechanism of each stress. Furthermore, it is a figure which shows the connection structure of the segment which provided the stiffening plate and the vertical rib. It is a figure which shows the connection structure of the segment which provided the stress transmission girder in the outer side of the main girder. It is a figure which shows the example which formed the rising part which comprises a part of new installation part. It is a figure which shows the example which provided the stress transmission girder in the natural ground side. It is a figure which shows the example which provided the stress transmission girder in both the natural ground side and the inner surface side, respectively. It is a block diagram of the segment for temporary installation which fills in the location equivalent to the connection part of a remaining part and a new installation part. It is a figure for demonstrating the construction method of the connection structure of the segment to which this invention is applied. It is another figure for demonstrating the construction method of the connection structure of the segment to which this invention is applied. (a) is a diagram for explaining the process of filling the filler in the construction method of the segment connection structure to which the present invention is applied, and (b) is an example in which the newly installed portion is configured as a steel reinforced concrete member. FIG. It is a figure which shows the example which connected the segment adjacent to a tunnel axial direction mutually in the tunnel axial direction. It is a figure which shows the example which applies this invention between the segments which comprise a newly installed part. It is a figure shown about the Example of the connection structure of the segment to which this invention is applied. It is a figure for demonstrating the prior art example of a non-cutting method. It is a figure which shows the completion figure of the tunnel branch merge part of the main line tunnel and the ramp tunnel constructed | assembled based on the non-open cutting method. It is a figure which shows the connection structure of the main line tunnel and the lamp tunnel in the past. (a) is a horizontal cross-sectional view of a portion A of the joint structure in FIG. 32, and (b) is a horizontal cross-sectional view of a B portion of the joint structure. It is a figure which shows the example which cross | intersects at a mutually different angle between the main girder extended from the main line tunnel side and the main girder extended from the ramp tunnel side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tunnel branch junction 2 Segment 4 Temporary segment 5 Removal part 11 Main line tunnel 12 Lamp tunnel 13 Tunnel 14 New part 15 Partition wall 22 Main girder 24 Supporting plate 25 End plate 26 Stress transmission girder 27 Opening holes 28 and 29 Stiffening Plates 30, 51 Vertical ribs 31, 53 Ring bolt hole 40 Rising part 41 Filler 52 Skin plate

Claims (7)

In the connecting structure of tunnel segments applied when connecting segments having a plurality of main beams orthogonal to the tunnel axis direction to each other,
The main girder of each segment is connected to another main girder adjacent in the tunnel axis direction via an end plate, and a support plate is provided at the tip, and between the end plate and the support plate, , Stress transmission girder is provided in the tunnel axis direction,
The main beam of the other segment is loosely fitted between the main beams of one segment with a gap capable of absorbing construction errors, and the end plate between the main beams of the one segment is a bearing plate at the tip of the main beam of the other segment. The stress transmission girder in the one segment is located on the inner surface of the tunnel and / or the outer surface of the tunnel from the main beam of the other segment,
Furthermore, the connecting structure of the segment characterized by filling the gap between the main beam of one segment loosely fitted with the main beam of the other segment with a filler. The main girder of each of the above segments is characterized in that the girder height is set lower at least in the section where the other stress transmission girder is located on the inner surface of the tunnel and / or the outer surface of the tunnel at the time of loose fitting. The segment connection structure according to claim 1. The main girders located at the axial ends of the segments adjacent to each other in the tunnel axial direction are joined,
The segment connecting structure according to claim 1 or 2, wherein the joined main beams are loosely fitted between the main beams of the other segment. The segment connection structure according to any one of claims 1 to 3, wherein a stiffening plate is disposed on a back surface of the end plate. The segment connecting structure according to any one of claims 1 to 4, wherein a stiffening plate is disposed on a back surface of the bearing plate. The segment connecting structure according to any one of claims 1 to 5, wherein the main girder of each segment is formed with an opening hole at least in a section in contact with the filler. The segment connection structure according to any one of claims 1 to 6, wherein the stress transmission girder is disposed so as to be within a girder height of the main girder.

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