JP4912726B2 - Connection structure between segment rings - Google Patents

Description

  The present invention relates to a connecting structure and an arrangement method of segments used when connecting adjacent segments in the circumferential direction to form a tunnel, and more particularly to a tunnel branching / merging portion where two tunnels branch or join, and an opening defect. The present invention relates to a segment connection structure and an arrangement method suitable for forming the outer periphery of a certain tunnel.

  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 open-cut method has the advantage that the soil 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 a branching junction has to 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. 23, this non-open cutting 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, although the method of constructing a tunnel branching junction based on this non-cutting method is disclosed in, for example, Non-Patent Document 1, in any method, the segments can be surely connected to each other in a limited space. There was a need for a high strength connecting structure that can be connected.

  FIG. 24A 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. 24B shows the distribution of 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.

  As shown in FIG. 25, when the branch pipe 213 is coupled to the main pipe 212 of the tunnel, it is necessary to remove the outer periphery of the main tunnel 212, but the cross section of the main pipe 212 of the tunnel is temporary. The defect part 211 is generated due to the defect. In the vicinity of the defect portion 211, the rigidity of the main pipe 212 is greatly reduced and stress is concentrated. In particular, in a tunnel structure in which axial force is excellent, how to efficiently transmit the axial force around the defect portion 211 to an adjacent segment becomes a big problem.

  By the way, the above-mentioned problem is not limited to the above-described branch / merging portion between the main pipe 212 and the branch pipe 213, but also in the structure in which the branch pipe branches from the emergency exit or sewer main pipe formed on the outer periphery of the tunnel, for example. It is done.

  Conventionally, in order to improve the transmission performance of the axial force around this defect, the main beams of the segments adjacent in the tunnel axis direction are fastened together by bolts between rings, and the shear transmission force of the bolts between rings makes it between rings. The method of transmitting force is generally used.

  However, in tunnels with a large depth or a large section, the axial force generated in the circumferential direction of the tunnel per segment ring becomes extremely large at 5000 to 10000 kN, so it is difficult to cope with this with only the proof strength and rigidity of the bolt. there were. In addition, when the number of bolts to be fastened and the diameter of the bolts are increased, the construction may be difficult due to a problem of the space at the site, and the placement of the bolts may be difficult.

  Incidentally, there are also examples in which the joints have higher yield strength and higher rigidity by increasing the diameter of the bolts, arranging the bolts in multiple stages, and increasing the thickness of the joint plate. However, when the bolt diameter is increased, for example, if the bolt diameter of about M20 mm is increased to about M56 mm, there is an adverse effect that the burden on the operator increases in the tightening operation for screwing the bolt. In addition, there is a problem in that a tightening device for tightening such a bolt having a large diameter becomes large, and a sufficient work space cannot be taken. Moreover, when bolts are arranged in multiple stages, the distance between adjacent bolts is extremely narrow, for example, about several tens of millimeters, and it is not possible to achieve on-site fastening work and high structural strength in terms of construction and performance. was there.

  In the past, in order to transmit the axial force around the tunnel opening between the rings, for example, the disclosed technique disclosed in Patent Document 1 has also been proposed. In the technology disclosed in Patent Document 1, a reinforcing girder is installed around the opening, and a structure for transmitting axial force to an adjacent ring is employed.

However, in the disclosed technique of Patent Document 1, since the structure must be made more complicated in order to connect the segment constituting the tunnel and the reinforcing beam, the manufacturing cost of the segment is increased, and the burden of construction labor is reduced. There was also a problem that it could not be solved.
JP 2000-226994 A "Construction Machinery" Nihon Kogyo Publishing, November 2005, P1-P56

  Therefore, the present invention has been devised in view of the above-described problems, and the object of the present invention is from a tunnel branching / merging portion where two tunnels branch or merge, an emergency exit of a tunnel, and a sewer main. For a segment structure with an opening defect such as a tunnel where a branch pipe branches, it can be reliably connected even in a narrow field space, and the axial force generated in the circumferential direction of the tunnel can be efficiently transmitted between the rings. An object of the present invention is to provide a connecting structure between segment rings having high proof stress and high rigidity, and a method for arranging the segments.

The connecting structure between segment rings according to claim 1 is a connecting structure between tunnel segment rings used when connecting adjacent segments to each other, and is orthogonal to the axial direction of the tunnel, and at least between the web and the web. A main girder having a flange formed on the inner surface is disposed at both ends of the segment in the axial direction and at substantially the center in the axial direction. The main girder disposed at both ends in the axial direction is twice as thick as the web, and a connecting plate is installed on the bottom surface of the flange between the main girders in the segment ring adjacent in the axial direction. Rutotomoni are mutually bolts joined with the spliced plate and the flange, the spliced plate projects from the joint plate to the circumferential direction of the tunnel, the tunnel axis Has a widened portion formed by the width, the widened portion is constructed except where across other segments circumferentially adjacent, the axial force generated in the tunnel circumferential direction be transmitted through the widened portion It is characterized by.

The segment arranging method according to claim 2 is a method for arranging the segments constituting the outer periphery of the tunnel branching / merging portion where the first tunnel and the second tunnel branch or merge. In the remaining portion segment constituting the remaining portion of the tunnel of 2, the segment ring is straddled with respect to the main girder which is orthogonal to the axial direction of the tunnel and has a web and a flange formed on at least the inner surface of the web. The attachment plate is constructed as described above, and the other segments except the remaining portion segment are removed from the first tunnel and the second tunnel, and the remaining portion segments of the first tunnel and the second tunnel are removed. In addition, a segment constituting the outer periphery of the tunnel branching junction is newly established, and between the segment and the remaining segment, Fasten the hands and install the adjacent segment in the axial direction of the newly established segment in the same way, and install the attachment plate so as to straddle the segment ring against the main girder in the newly established segment adjacent to the axial direction. It is characterized by erection.

  In the present invention having the above-described configuration, high strength and rigidity can be reliably connected even in a narrow field space, and the axial force generated in the circumferential direction of the tunnel can be efficiently transmitted between the rings. It becomes possible to make the connection structure between the segment rings having both.

  Hereinafter, as a best mode for carrying out the present invention, a connection structure between segment rings constituting the outer periphery of a tunnel will be described in detail with reference to the drawings.

  The connection structure between the segment rings to which the present invention is applied is applied around the opening 17 formed to connect the branch pipe 19 to the main pipe 18 of the tunnel as shown in FIG.

  The main pipe 18 is a pipe represented by a sewer pipe or the like. The opening 17 formed in the main pipe 18 is for flowing the fluid from the branch pipe 19. In other words, when the main pipe 18 is constructed, it is necessary to form the opening 17 in advance for the branch pipe 19 to be connected later, so that a defective part is generated.

  Incidentally, the shape of the opening 17 is complicated when the branch pipe 19 is connected to the main pipe 18 at an angle. Further, the end portion of the opening 17 is constituted by a segment having an oblique inclination. The gap between the main pipe 18 and the branch pipe 19 is generally not rigidly connected, and is inserted so that the segment outer surface of the branch pipe tunnel is along the segment cross section of the opening circumference where the main tunnel is cut, In many cases, the gap has a so-called pin structure in which a water-stopping treatment is performed by filling a filler such as mortar.

  FIG. 2 is a perspective view of the segment ring coupling structure 2 to which the present invention is applied. The connecting structure 2 is expanded in the axial direction so as to straddle the joint ring 23 formed on the circumferential contact surface 21 of the segment 3, the main girders 24a to 24c orthogonal to the axial direction of the tunnel, and the segment ring. And contact plates 25a and 25b.

  The segment 3 is a steel shell segment manufactured by assembling or casting a steel plate, or a synthetic segment in which the steel shell is filled with concrete. The example of FIG. 2 shows a steel shell segment, and the natural ground surface is covered with a skin plate 26. When the segment 3 is composed of a synthetic segment, concrete is filled in the steel shell, but a reinforcing structure in which reinforcing bars and deformed steel bars (not shown) are arranged inside the concrete may be adopted.

  In this segment 3, three main beams 24a to 24c are further arranged. The main girder 24a and the main girder 24c are disposed at both ends of the segment 3 in the axial direction. In addition, it is preferable to arrange a middle main girder such as the main girder 24b. In that case, at least one middle girder is arranged between the main girder 24a and the main girder 24c. The main girders 24a to 24c include webs 31a to 31c, natural mountain side flanges (also referred to as upper flanges) 32a to 32c formed above and below the webs 31a to 31c, and inner air surface side flanges (also referred to as lower flanges) 33a. ~ 33c. The reason why the upper and lower flanges 32 and 33 are intentionally formed is to reinforce the cross section of the main girder 24, and for that purpose, at the upper and lower ends of the main girder 24 in the height direction, the flange is perpendicular to the web 31. This is because it is desirable to form 32 and 33.

  The upper flanges 32 a to 32 c are fixed above the neutral shaft 22, and the lower flanges 33 a to 33 c are fixed below the neutral shaft 22. In addition, the lower flanges 33a to 33c are arranged with a gap therebetween. Incidentally, the upper flanges 32a and 32c and the lower flanges 33a and 33c do not protrude from the outside of the webs 31a and 31c in the axial direction so that the main girders 24a and the main girders 24c provided at both ends in the axial direction have a U-shape. It is configured. On the other hand, the main girder 24b formed substantially in the center in the axial direction is fixed in such a shape that the upper flange 32b and the lower flange 33b protrude to both sides via the web 31b. Further, a bolt hole 41 is formed in each of the lower flanges 33a and 33c.

  The web 31 has a height of about 500 to 2000 mm, but in practice, the necessary dimensions are determined according to the tunnel depth, tunnel diameter, and the like. Bolt holes 43 are formed in the web 31a and the web 31c formed at both ends in the axial direction. The bolt hole 43 is used to join the webs 31a and 31c of the segment 3 adjacent to each other in the axial direction. The number, diameter, and arrangement of the bolt holes 43 are determined according to the axial transmission force required from the design.

  The distance between the flanges 32a and 33a in the main girder 24a and the flanges 32b and 33b in the main girder 24b, and the distance between the flanges 32b and 33b in the main girder 24b and the flanges 32c and 33c in the main girder 24c are from the viewpoint of workability. Therefore, it is necessary to secure about 200 to 300 mm.

  Further, the thickness of the web 31 and the flanges 32 and 33 constituting the main girder 24 is about 30 to 100 mm, and the natural skin side skin plate 26 is about 3 to 15 mm. The strength of the steel material constituting the main girder 24 and the skin plate 26 is selected from 400 to 580 MPa class according to the design load.

  Further, the thickness of the web 31 may be configured such that the thickness of the central web 31b is twice the thickness of the webs 31a and 31c at both ends in the axial direction. The reason is that the outer main girders 24a and 24c are joined to the main girders 24c and 24a of the segment 3 adjacent to each other in the axial direction so as to match the mechanical characteristics of the main girders 24b.

  The joint plate 23 is provided between the web 31a and the web 31b and between the web 31b and the web 31c. The joint plate 23 is arranged so that the segments 3 adjacent to each other in the circumferential direction come into contact with each other. The joint plate 23 is preferably extended from the upper flange 32 to the lower flange 33.

  The joint plate 23 is provided with bolt holes 42 for screwing bolts in two stages. The bolt hole 42 is used for abutting the joint plates 23 of the adjacent segments 3 to each other and inserting a bolt (not shown) therethrough. The arrangement of the bolt holes 42 is determined by the necessary proof strength of the bolts and the interval required for tightening the water stop material 44. In order to evenly resist the expansion reaction force of the water stop material 44, the distance between the bolts is determined. It is desirable to arrange so that the maximum is about 500 mm. In addition, the distance between the bolt holes 42 is at least about 100 mm so as not to hinder the bolt fastening operation.

  The attachment plate 25a is installed on the bottom surface of the lower flange 33a, and the attachment plate 25c is installed on the bottom surface of the lower flange 33c. Each attachment plate 25 is formed with a bolt hole 46, and the bolt hole 46 and the bolt hole 43 of the lower flange 33 are combined to be bolted together. That is, each attachment plate 25 is constructed so as to straddle the bottom surface of each lower flange 33 in the segment 3 adjacent in the axial direction.

  The required number of bolts for this joining is determined from the transmission strength of one bolt based on the transmission force to be transmitted. Further, the length of the attachment plate 25 is adjusted so as to satisfy the required number of bolts. The thickness of the contact plate 25 is determined by the design transmission force to be transmitted within a range of about 9 to 70 mm.

  Moreover, the space | interval of the hole 46 for bolts takes the space | interval of about 100-150 mm at the minimum considering workability. The number of bolts arranged in the axial direction of the segment 3 is preferably about 2 to 10 rows.

  A water stop material 44 may be provided around the segment 3. The water blocking material 44 may be composed of a rubber seal member or the like for preventing leakage of groundwater from the natural mountain side to the inner air surface side. It may react to expand the volume and block water. This water stop material 44 is arrange | positioned so that the segments which adjoin in the circumferential direction and an axial direction may face, and 1 or 2 strip | lines are arrange | positioned as needed. The water blocking material 44 may be formed in a groove portion (not shown) formed in advance. The water blocking material 44 is provided even if it continues from the joint plate 23 to the outer surface of the main girder 24.

  In the above-described example, the case where three main girders 24 are provided has been described as an example. However, the present invention is not limited to this case, and there are two (no medium main gird) or four or more (medium main girders). (2 or more) main girders 24 may be used. However, 3 or more are preferable for securing strength and rigidity, and 5 or less are preferable for ease of processing and cost.

  The upper flange (mountain-side flange) 32 disposed at the upper end of the web 31 may be omitted depending on the tunnel conditions, but it is preferable that the effect of improving strength and rigidity is high.

  Next, another structural example of the segment ring coupling structure to which the present invention is applied will be described with reference to the drawings. In the following configuration examples, the same components and members as those of the connection structure shown in FIG.

  The connection structure 4 shown in FIG. 3 is obtained by eliminating the central main beam 24b in the connection structure 2 shown in FIG. That is, in this connection structure 4, it is comprised only by the main girders 24a and 24c formed in the axial direction both ends, and the joint plate 23 is provided over one sheet between the web 31a and the web 31c, and the upper flange 32 is provided. To the lower flange 33.

  In the connecting structure 5 shown in FIG. 4, in addition to the attachment plate 25, an attachment plate 53 is further installed between lower flanges 33 adjacent in the axial direction. Thereby, it is possible to further improve the axial force transmission performance.

  The connecting structure 5 may be configured by only the attachment plate 53 by removing the attachment plate 25 as shown in FIG. This also improves the axial force transmission performance.

  In the connecting structure 7a shown in FIG. 6, bolt holes 43 are formed in a plurality of stages on the web 31a and the web 31c formed at both ends in the axial direction in the vicinity of the joint portion where at least the attachment plate 25 is disposed. It is an example. The bolt hole 43 is used to join the webs 31a and 31c of the segment 3 adjacent to each other in the axial direction. The number, diameter, and arrangement of the bolt holes 43 are determined according to the axial transmission force required from the design. If the main girder 24 is a segment having a height of about 500 mm, the bolt holes 43 through which the bolts for connecting the rings of the segment 3 are inserted should be about 3 steps × 3 rows. It can be said that it is appropriate from the construction side. The connection structure 7b shown in FIG. 7 is an example in which the attachment plate 53 is further installed between the lower flanges 33 adjacent in the axial direction, and the bolt holes 43 are formed in the vicinity thereof.

  The connection structures 2 and 5 to 7 according to the present invention having the above-described configuration are generated in the circumferential direction of the tunnel when applied to the periphery of the opening 17 formed to connect the branch pipe 19 to the tunnel main pipe 18. The axial force to be transmitted can be efficiently transmitted between the rings.

  FIG. 8 is an enlarged perspective view of the attachment plate 25 installed so as to straddle the segment ring between the lower flanges 33. The attachment plate 25 is provided with a bolt hole 46 for joining to the lower flange 33, and the bolt is passed through the fastening plate 25 and fastened to the lower flange 33. As a result, the axial transmission force f <b> 1 in the tunnel circumferential direction generated in one segment 3 is transmitted to the joint surface 61 between the lower flange 33 and the attachment plate 25. Then, a load is transmitted from the joint surface 61 to the adjacent ring direction by the shear strength of the attachment plate cross section 62, and further transmitted to the segment 3 adjacent in the axial direction via the joint surface 63. . As a result, an axial transmission force f2 is obtained on the adjacent segment 3 side. That is, the connection structures 2, 5 to 7 to which the present invention is applied can efficiently transmit the axial force generated in the circumferential direction of the tunnel between the rings, and can be a connection structure with higher proof strength and rigidity. It becomes possible.

  Actually, the diameter and the number of bolt holes 46 formed in the attachment plate 25 are determined based on the transmission force obtained from the structural calculation. More specifically, the diameter and the number of the bolt holes 46 determine necessary specifications from the transmission strength per bolt. The bolt diameter is set so as to ensure the required performance when the bolt defect is considered with respect to the width of the attachment plate 25. The length of the attachment plate 25 is set to a length that allows the necessary number of bolts to be arranged while securing the bolt interval. Further, the length is equal to or longer than a necessary length capable of securing the shear strength of the above-mentioned connecting plate section 62.

  The connection structure 8a shown in FIG. 9 is an example in which an attachment plate 52 widened in the circumferential direction is provided so as to straddle the segments 3 adjacent in the circumferential direction of the tunnel. Through the bolt hole 46 provided in the attachment plate 52, not only the lower flange 33 of the segment 3 adjacent in the axial direction but also the lower flange 33 of the segment 3 adjacent in the circumferential direction are bolted. Will be.

  In this connection structure 8a, it is possible to counter a bending moment that is applied from the inner surface to the ground. That is, as a result of the bending moment being applied, a compressive force is applied above the neutral shaft 22, and a tensile force is applied below the neutral shaft 22. This tensile force is transmitted by the attachment plate 52 erected in the main beam 24 in the axial direction. That is, in this connection structure 8, it is possible to increase both yield strength and rigidity.

As an alternative spliced plate 52, it may be used spliced plate 52 as shown in the connection structure 8b as shown in FIG. 10 for example. The attachment plate 52 excludes a portion widened so as to straddle the segments adjacent in the circumferential direction. However, since it is possible to flow an axial force in the direction of the arrow 65 in the figure, the desired effect of the present invention can be obtained.

FIG. 11 shows an example in which the attachment plate 53 is further installed between the lower flanges 33 adjacent in the axial direction in the connection structure 8c.

  12 is an example in which bolt holes 43 are formed in a plurality of stages in the web 31a and the web 31c formed at both ends in the axial direction at least near the joint portion. The bolt hole 43 is used to join the webs 31a and 31c of the segment 3 adjacent to each other in the axial direction. At this time, as shown in FIG. 13, the attachment plate 53 may be further installed between the lower flanges 33 adjacent in the axial direction, and the bolt holes 43 may be formed in the vicinity thereof.

  Note that the present invention is not limited to the case where the present invention is applied to the periphery of the opening 17 formed to connect the branch pipe 19 to the main pipe 18 of the tunnel. You may make it apply when constructing the tunnel branch merge part to merge.

  First, the construction method of the tunnel branch junction 1 to which the connection structures 2 and 5 to 9 are applied will be described in detail with reference to the drawings.

  As shown in FIG. 14, first, in the main tunnel 11, the remaining portion 11 a and the removal portion 11 b are separated. Similarly, in the ramp tunnel 12, the remaining portion 12a and the removal portion 12b are separated. Next, the ground 71 and the ceiling 72 of the cavity 70 as shown in FIG.

  The reason for this freezing is to prevent water from entering the cavity 70. Next, the ground between the main line tunnel 11 and the ramp tunnel 12 is excavated in the ground, and then the segments constituting the removed portions 11b and 12b are removed.

  Next, as shown in FIG. 16, a new portion 14 is newly provided between the remaining portion 11a and the remaining portion 12a. The newly installed portion 14 constitutes the outer periphery of the tunnel branching / merging portion 1.

  The construction method of the newly installed part 14 will be described in more detail. 17 and 18 show a cross-sectional view of the tunnel branching junction 1 on the left side, and a top view of the tunnel branching junction 1 on the right side. This top view shows a case in which 1 to 6 rows of segment rings are formed from the left side to the right side in the drawing. From step S11 to step S15, the newly installed portion 14 extends from 1 row to 6 rows. Shows the case of building.

  In step S11, the separation between the remaining portion 11a and the removal portion 11b in the main tunnel 11 and the separation between the remaining portion 12a and the removal portion 12b in the ramp tunnel 12 are not yet completed. It remains as it is. In such a case, the flow of force in the circumferential direction of the tunnel indicated by the arrows in the figure is parallel to each other without straddling the segment ring.

  Between the segments 3 constituting the remaining portions 11a and 12a, any one of the connection structures 2 and 5 to 9 described above is applied (in the following description, the case where the connection structure 2 is applied). I'll explain with an example). That is, in this step S11, the attachment plate 25 is constructed so as to straddle the segment rings adjacent in the axial direction in the segments 3 constituting the remaining portions 11a and 12a. As a result, the attachment plate 25_1 is between the first and second segment rings, and the attachment plate 25_2 is between the third and fourth rows between the second and third segment rings. Between the segment rings, the attachment plate 25_3 is interposed between the fourth and fifth row segment rings, and the attachment plate 25_4 is further attached between the fifth and sixth row segment rings. The plate 25_5 will be installed. Incidentally, the installed attachment plate 25 does not function in the step S11.

  Next, it transfers to step S12 and the segment which comprises the removal parts 11b_1 and 11b_2 and 12b_1 and 12b_2 which comprise the 1st-2nd column is removed. The cross-sectional view in step S12 shows a state in which the segments constituting the removed portions 11b_1 and 11b_2 and 12b_1 and 12b_2 have been removed, and the ground surface 71 and the ceiling 72 of the cavity portion 70 have been frozen. Incidentally, in this step S12, in the 3rd to 6th rows, the ground pile 77 remains between the removed portions 11b and 12b.

  As a result of removing the removal portions 11b and 12b in this step S12, the axial force generated before the removal is released, and the stress flowing in the first and second rows is based on the mechanism described above via the attachment plate 25. Then, it flows into the removal parts 12b_3 to 12b_6.

  Next, the process proceeds to step S13, and a new part 14_1 is constructed in the first column. That is, in this step S13, the segment 3 of the newly installed portion 14_1 that constitutes the outer periphery of the tunnel branch junction 1 is newly established between the segments that constitute the remaining portions 11a and 12a of the main tunnel 11 and the ramp tunnel 12, and A joint is fastened between the segment 3 and the segments constituting the remaining portions 11a and 12a. For fastening of the joint, for example, the joint plates 23 of the adjacent segments 3 are brought into contact with the bolt holes 42 of the joint plate 23, and bolts (not shown) are inserted and joined.

  Here, the case where two segments 3 are connected in the circumferential direction is illustrated for the newly installed portion 14_1. At this stage, the stress propagated in the first row is not transmitted to the segment 3 constituting the new portion 14_1. Incidentally, the cross-sectional view shown in step S13 shows a cross section of the first-row segment ring in which the new portion 14_1 is constructed.

  Next, the process proceeds to step S14, and the segments constituting the removal units 11b_3 and 12b_3 constituting the third row are removed. In this step S14, in the 4th to 6th rows, the ground mountain 77 still remains between the removed portions 11b and 12b. In step S14, the stress propagated in the second row flows into the newly installed portion 14_1 in the first row via the attachment plate 25_1, and the stress propagated in the third row becomes 4 through the attachment plate 25_3. It will flow into the line.

  Next, the process proceeds to step S15, and the new section 14_2 is disposed in the second row. The segments 3 constituting the new part 14_2 are arranged in a staggered manner with the segments constituting the new part 14_1. The segment 3 constituting the newly installed portion 14_2 is arranged so as to be a so-called potato joint with respect to the remaining portion 12a between the segment 3 constituting the newly installed portion 14_1. Thereby, the segment which comprises the remaining part 12a, and the segment 3 which comprises the said newly installed part 14_1 and 14_2 are arrange | positioned so that a mutual joint surface may become a straight line toward an axial direction. By repeatedly executing the above steps, the branching / merging unit 1 is constructed.

  In particular, in the joint portion between the remaining portion 12a and the newly installed portion 14_1, it is necessary to make a joint that is excellent in connection work because the adjacent ring segments 3 need to be newly installed, and the bending moment is not large. It is desirable to use a tuber joint. On the other hand, in the center part of the segment 3 which comprises the new installation part 14, since a bending moment is large and the relationship with the remaining parts 11a and 12a is also lost, it is desirable to comprise by staggered arrangement.

  Further, the above-described connection structure 2 is also applied between the segments 3 constituting the newly installed portions 14_1 and 14_2. That is, the contact plate 25 'is installed in the axial direction between the newly installed portions 14_1 and 14_2. As a result, in the stress transmission, the stress propagating in the third row flows into the segment rings (newly installed portions 14_1 and 14_2) on both sides. The stress flowing into the newly installed portions 14_1 and 14_2 is transmitted between the newly installed portions 14_1 and 14_2 through the attachment plate 25 '.

  As described above, by removing the removal portions 11b and 12b, an opening defect is generated, and stress cannot flow through the opening defect, but the connection structure 2 according to the present invention is not limited to the remaining portions 11a and 12a. It is possible to efficiently transmit the axial force generated in the circumferential direction of the tunnel between the rings by installing between the new portions 14 constituting the row before the opening defect portion.

  FIG. 19 shows an example in which the connection structure 8 is applied to the remaining portions 11a and 12a. Stress transmission between the remaining portion 11a (12a) is performed via the attachment plate 53. Stress transmission between the remaining portion 11a (12a) and the newly installed portion 14 and stress transmission between the segments constituting the new installed portion 14 are as follows. This is done via the attachment plate 52. This also allows the axial force generated in the tunnel circumferential direction to be efficiently transmitted between the rings.

  In the above-described example, the branch junction 1 formed between the main tunnel 11 and the ramp tunnel 12 has been described as an example. However, the present invention is not limited to this case, and any two tunnels can be connected. Of course, the present invention may be applied to the branching junction formed by

  Taking the branch and merge part 1 of a deep tunnel with a cover of 50m as an example, the specifications of the connection structure 2 are estimated.

  The cross section of the branch merge section 1 is a horizontally long tunnel cross section having a total width of 22 m and a height of 15 m. In the case of constructing the branching / merging portion 1 by the non-opening method, it is assumed that the segment 3 constituting the removal portions 11b and 12b is removed during the construction. The model of 6 rings which consists of 6 rows as shown in FIG. 20 is made, the 1st and 2nd rows are the state where the newly installed portion 14 is constructed, and the 3rd and 4th rows are after the removal portions 11b and 12b are removed. The state and the fifth to sixth columns show the state before the removal of the segments constituting the removal portions 11b and 12b.

  At this time, the shearing springs 301 in the tunnel normal direction and the tangential direction are distributed and connected around the tunnel between the rings, and the transmission force between the rings is calculated. The maximum shearing force generated between the rings in the circumferential direction of the tunnel, that is, the maximum value of the transmission force of the shear spring between the rings is 1000 kN.

  Further, as shown in FIG. 21, the height of the main beam 24 is 1000 mm, the width of the segment 3 is 1200 mm, the thickness of the flanges 32 and 33 of the main beam 24 is 75 mm, and the width of the flanges 32a and 33a and the flanges 32c and 33c. The width of the flanges 32b and 33b is set to 340 mm, the thickness of the webs 31a and 31c is set to 30 mm, the thickness of the web 31b is set to 60 mm, and the thickness of the skin plate 26 is set to 8 mm.

  Further, the thickness of the joint plate 23 is 30 mm, and bolt holes 42 for screwing the bolts are provided over 2 rows × 4 rows. The bolt to be screwed through the bolt hole 42 is an M36 short bolt type.

  Further, regarding the specifications of the contact plate 25, when the diameter of the bolt inserted into the bolt hole 46 is M30 mm and the friction resistance of one surface of the SHTB bolt is 161 kN / piece, the necessary number of bolts is 1000 kN / 161 kN = 6. .It becomes two. Regarding the size of the attachment plate 25, as shown in FIG. 22, when the edge distance between the bolt holes 46 is 100 mm and the interval between the bolt holes 46 is 150 mm, the length of the attachment plate 25 is 100 mm × 2 + 150 mm × 5 = 950 mm. Further, when the plate thickness of the attachment plate 25 is 12 mm and the material is SM490Y (allowable shear stress degree 135 MPa),

  The degree of generated shear stress τ in the contact plate cross section 62 is τ = 1000 kN × 1000 / (950 mm × 12 mm) = 88 MPa. For this reason, it can be seen that the generated shear stress level τ is lower than the allowable shear stress level under the above-described specifications.

It is a figure which shows the opening periphery where the connection structure of the segment ring to which this invention is applied is applied. It is a perspective view of the connection structure to which the present invention is applied. It is a perspective view of the connection structure which removed the center main beam. In the connection structure to which the present invention is applied, it is a diagram illustrating an example in which an attachment plate is separately installed in the axial direction. It is a figure which shows the other structural example of the connection structure of FIG. It is a figure which shows the example which formed the hole for volt | bolts over the multi stage in the web formed in the axial direction both ends at least in the joint part vicinity. It is a figure which shows the other structural example of the connection structure of FIG. It is a figure for demonstrating the effect of the connection structure to which this invention is applied. It is a figure which shows the example which provides the attachment board diameter-expanded in the circumferential direction so that the segment adjacent to the circumferential direction of a tunnel may be straddled. It is a figure shown about using the attachment board except the location expanded in diameter so that the segment which adjoins the circumferential direction may be straddled. FIG. 10 is a diagram illustrating an example in which an attachment plate is further installed between lower flanges adjacent in the axial direction in the connection structure of FIG. 9. FIG. 10 is a diagram illustrating an example in which bolt holes are formed in a plurality of stages on the web formed at both ends in the axial direction in the connection structure of FIG. 9. It is a figure which shows the other structural example of the connection structure of FIG. It is a figure for demonstrating the construction method of the tunnel branch merge part to which the connection structure which concerns on this invention is applied. It is a figure which shows the cavity part obtained by excavating the ground between a main line tunnel and a ramp tunnel. It is a figure shown about the case where a new installation part is newly provided between remaining parts. It is a figure for demonstrating in more detail the construction method of the tunnel branch merge part to which the connection structure which concerns on this invention is applied. It is another figure for demonstrating in more detail the construction method of the tunnel branch merge part to which the connection structure which concerns on this invention is applied. It is a figure which shows the example which applies a connection structure in a remaining part. It is the schematic of the model for determining a design specification. It is a figure shown about the example of a design based on the model of FIG. It is a figure which shows the size structural example of an attachment board. 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 for demonstrating the problem of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tunnel branch merge part 2 Connection structure 3 Segment 11 Main line tunnel 12 Lamp tunnel 13 Tunnel 14 New part 15 Partition wall 21 Circumferential contact surface 22 Neutral shaft 23 Joint plate 24 Main girder 25 Connecting plate 26 Skin plate 31 Web 32 On Flange 33 Lower flange 41 to 43, 46 Bolt hole 44 Water stop material

Claims (2)

In the connecting structure between the segment rings for tunnels used when connecting adjacent segments to each other,
A main girder orthogonal to the axial direction of the tunnel and having a web and a flange formed on at least the inner surface of the web is disposed at both axial ends of the segment and substantially in the axial direction.
The web thickness in the main girder disposed substantially in the center in the axial direction is constituted by twice the thickness of the web in the main girder disposed at both ends in the axial direction.
Between the main girders in the segment ring adjacent in the axial direction, an attachment plate is installed on the bottom surface of the flange, and the attachment plate and the flange are bolted to each other,
The attachment plate protrudes from the joint plate in the circumferential direction of the tunnel and has a widened portion that is widened in the tunnel axial direction, and the widened portion is excluded except for a portion straddling another segment adjacent in the circumferential direction. A connecting structure between segment rings, which is configured to transmit an axial force generated in the circumferential direction of the tunnel through the widened portion . In the arrangement method of the segments constituting the outer periphery of the tunnel branching junction where the first tunnel and the second tunnel branch or merge,
In the remaining part segment constituting the remaining part of the first tunnel and the second tunnel, for a main girder orthogonal to the axial direction of the tunnel and having a web and a flange formed on at least the inner surface of the web. And lay the attachment plate across the segment ring,
Removing other segments from the first tunnel and the second tunnel except for the remaining segment,
A segment constituting the outer periphery of the tunnel branching junction is newly established between the remaining segment of the first tunnel and the second tunnel, and a joint is fastened between the segment and the remaining segment. And
In the same way, a segment adjacent in the axial direction of the newly established segment is newly established.
A segment arrangement method, wherein an attachment plate is constructed so as to straddle a segment ring with respect to the main girder in the newly established segments adjacent to each other in the axial direction.

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