JP2007092356A - Tunnel structure having large cross section and its construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tunnel structure having a large cross section capable of reducing a cost by reducing man-hour in site work. <P>SOLUTION: The tunnel structure 1 is equipped with a curved arch section 3 in the shape of an arch. The arch section 3 is formed of a precast concrete-made arch member and an arch reinforcing section formed on the arch member by a cast-in-place concrete. The arch member 3a is constituted by dividing it into right and left parts in the top section 9. The central bottom slab section 4 is provided between a pair of L-shaped members 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is mainly used for a tunnel formed by a cutting method, and particularly relates to a tunnel structure having a large cross section.

Conventionally, this type of large-section tunnel is generally constructed by assembling a formwork on the ground and placing concrete in the formwork on-site. However, the construction of a tunnel using cast-in-place concrete has the problem that the number of work steps increases and costs increase. For such a problem, a pair of left and right arc plate-shaped precast concrete plates are arched between both ends in the width direction of the bottom plate extending in the tunnel length direction and connected in the tunnel length direction. At both ends in the width direction, side bands that bulge upward at an appropriate distance from the outer surface of the leg part and extend in the tunnel length direction on the outside of the leg part of each precast concrete plate are integrally provided. A pressure receiving member is interposed therebetween, and a leg portion is fastened to a side band by a fastening member such as a bolt, and a bank is applied to cover the concrete plate (for example, Patent Document 1). ).
JP 7-21617 A

  However, in the tunnel structure described above, although the arc plate can be constituted by a precast concrete plate to reduce the cost, it is necessary to form the bottom plate extending in the length direction of the tunnel with the cast-in-place concrete, which is complicated. There was a limit to the cost that could be reduced.

  In view of the above problems, an object of the present invention is to provide a tunnel structure having a large cross section and a method for constructing the same that can reduce costs by reducing the number of man-hours required for field work.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a tunnel structure including an arch portion curved in an arch shape, wherein the arch portion includes an arch member made of precast concrete and a cast-in-place concrete. It is formed by the arch reinforcement part formed on top.

  The invention according to claim 2 is characterized in that, in claim 1, the arch member is divided into left and right at the top.

  The invention according to claim 3 is characterized in that, in claim 1 or 2, the arch member comprises an implant.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the arch member is disposed between a pair of left and right precast concrete L-shaped members extending in the tunnel height direction from the tunnel bottom side. A central bottom plate portion is provided between the L-shaped members.

  The invention according to claim 5 is the invention according to any one of claims 1 to 3, wherein the arch member is horizontally disposed between a pair of left and right precast concrete L-shaped members extending in the tunnel height direction from the tunnel bottom side. A back bottom plate portion is provided on the back surface of the L-shaped member.

  According to a sixth aspect of the present invention, a pair of left and right precast concrete L-shaped members extending from the tunnel bottom side in the tunnel height direction is installed, an arch member is horizontally mounted, and the L-shaped member and the arch member And an arch reinforcing portion is formed on the upper surface of the arch member by cast-in-place concrete.

  Further, the invention according to claim 7 is provided by installing a pair of left and right precast concrete L-shaped members extending in the tunnel height direction from the tunnel bottom side, and connecting the pair of L-shaped members with a spacing member. An arch member is horizontally mounted, the L-shaped member and the arch member are fastened, the spacing member is removed, and an arch reinforcing portion is formed on the upper surface of the arch member by cast-in-place concrete. .

  According to the concrete structure having a large cross section according to claim 1 of the present invention, the construction of the member made of precast concrete divided into a plurality of parts reduces the man-hours for on-site work even with a large cross section, and reduces the cost. Can be reduced. In addition, by forming the arch reinforcing part with cast-in-place concrete, the arch member can function as a part of the mold for forming the arch reinforcing part, so that the amount of the member for the mold is reduced and the mold The number of work steps for installing and dismantling the frame can be reduced, and the cost can be further reduced.

  Moreover, according to the large cross-section concrete structure according to claim 2, the arch member is divided and configured to facilitate transportation, and even a tunnel having a large cross section is constructed with a precast concrete member. Cost can be further reduced.

  Moreover, according to the concrete structure of the large cross section according to claim 3, by embedding the embedded body, the arch member can be reduced in weight, and the material cost and the transportation cost can be reduced, and the work on the site can be easily performed. Therefore, the cost can be further reduced.

  Moreover, according to the concrete structure of the large cross section of Claim 4, since a side wall can become independent by comprising a side wall with the L-shaped member, it can install easily and can reduce work man-hours. In addition, by providing the central bottom plate portion, it is possible to reliably build even in soft ground.

  Moreover, according to the large cross-section concrete structure of Claim 5, since a side wall can be self-supporting because it comprised the L-shaped member, it can install easily and can reduce work man-hours. Moreover, since the back bottom plate portion is provided, it can be constructed with a small amount of material, so that cost can be reduced.

  Moreover, according to the large cross-section concrete structure of Claim 6, even if it is a tunnel which has a larger inner space, it can construct | assemble by the member made from precast concrete, Therefore A cost can be reduced. In addition, by forming the arch reinforcing part with cast-in-place concrete, the arch member can function as a part of the mold for forming the arch reinforcing part, so that the amount of the member for the mold is reduced and the mold The number of work steps for installing and dismantling the frame can be reduced, and the cost can be further reduced.

  According to the method for constructing a tunnel having a large cross section according to claim 7, since the pair of left and right L-shaped members are connected to each other by the holding member, the L-shaped member can be prevented from falling down during the construction, and at a predetermined interval. Therefore, it is possible to construct a tunnel having a large cross section safely and easily, so that the cost can be reduced.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  A tunnel structure 1 shown in FIG. 1 includes a pair of left and right precast concrete L-shaped members 2 extending in the tunnel height direction from a tunnel bottom side portion, and an arch portion 3 horizontally mounted above the L-shaped member 2. It is formed. Further, between the L-shaped members 2, a central bottom slab portion 4 which is a bottom slab portion is formed of cast-in-place concrete.

  The L-shaped member 2 includes a bottom portion 5 that contacts the ground G and a side wall portion 6 that extends perpendicularly from one end of the bottom portion 5 and is formed in advance at a factory. The side wall portion 6 is gently curved upward on the inner side, that is, toward the other end side of the bottom portion 5, and is formed at a height approximately in the middle of the height of the tunnel. Moreover, the upper end of the side wall part 6 is taper-processed so that it may become substantially half thickness. Further, the L-shaped member 2 is provided with a vertical fastening insertion hole 7 for performing vertical fastening in the length direction of the tunnel.

  The arch part 3 is formed by an arch member 3a made of precast concrete and an arch reinforcing part 3b formed of cast-in-place concrete.

  The arch member 3a is a rectangular plate member having a thickness approximately half that of the side wall portion 6 that is curved in the width direction of the tunnel so as to protrude upward, and is formed in advance at a factory. It is. The arch member 3a includes a joint portion 8 provided at one end in the circumferential direction and a top portion 9 provided at the other end. Further, the arch member 3a is provided with a vertical fastening insertion hole 7 on the outer peripheral surface for vertical fastening in the length direction of the tunnel.

  The arch reinforcing portion 3b is formed of cast-in-place concrete on the upper surface of the arch member 3a, and is formed to a thickness having a predetermined strength that the arch portion 3 is required together with the arch member 3a.

  An embedded body 17 is embedded in the side wall portion 6 of the L-shaped member 2, whereby the L-shaped member 2 can be reduced in weight. Various types of the embedded body 17 are conceivable. For example, a tube or a cylinder may be formed of paper, cardboard, polystyrene foam, or the like, or a polyvinyl chloride tube may be used. Moreover, it is good also as replacing with the reinforcing bar arranged by the L-shaped member 2 and the arch member 3a by comprising the embedded body 17 with a steel pipe. Although not shown, an embedded body may be embedded in the arch member 3a. In this case, the embedded body embedded in the arch member 3a has a smaller diameter than the embedded body 17 embedded in the side wall portion 6, and is curved in the circumferential direction by being provided in a plurality in the circumferential direction. It can be buried over almost the whole area.

  As shown in FIG. 2, a connection joint 10 and a guide member 11 are provided at the upper end of the side wall portion 6. The connection joint 10 protrudes perpendicularly to the upper end surface 6 a of the side wall portion 6. The guide member 11 is a steel plate member, is fixed to the inside of the side wall portion 6, and protrudes in a direction perpendicular to the upper end surface 6a. A joint receiving portion 12 with which a joint 10 provided on the upper end surface 6a of the side wall portion 6 of the L-shaped member 2 is engaged with a joint surface 8a of the joint portion 8 provided at one end in the circumferential direction of the arch member 3a. Is installed.

  As shown in FIG. 3, an insertion hole 15 penetrating perpendicularly to the top end face 9a is formed in the top 9 provided at the other end in the circumferential direction of the arch member 3a. A seat surface 16 is provided in an opening formed on the surface side of the arch member 3a by the insertion hole 15. The arch members 3a are configured as a pair of left and right, and are arranged at the ceiling portion of the tunnel so as to face each other at the top end face 9a.

  Next, a method for constructing the tunnel structure 1 will be described with reference to the drawings.

  First, the case where the precast concrete L-shaped member 2 and the arch member 3a are installed will be described. As shown in FIG. 4 (A), a foundation 20 is laid on the ground G that has been cut by using leveled concrete. Next, after constructing a mortar (not shown) on the foundation 20, the L-shaped member 2 is installed as a pair of left and right. Since the L-shaped member 2 is integrated with the bottom portion 5, it can stand on its own and workability can be improved.

  In this way, the same operation is repeated in the length direction of the tunnel, and the pair of left and right L-shaped members 2 are connected by the spacing member 27. The spacing member 27 is composed of a pair of horizontal rods 28a having male screws formed at both ends. One end of each horizontal bar 28a is inserted into a through-hole formed in the side wall 6 of the L-shaped member 2 in advance, and is fixed to the nut 26b via the plate 29. The other ends of the spacing members 27 are connected to each other by a connecting means 28b, for example, a turnbuckle, at the approximate center of the pair of L-shaped members 2. As a result, the L-shaped member 2 can be prevented from falling down during the construction, and can be held at a predetermined interval. The spacing member 27 horizontally mounted as described above is removed after the L-shaped member 2 and the arch member 3a are fastened by a method described later.

  Next, as shown in FIG. 4 (B), a movable base 21 is installed approximately in the middle of the pair of L-shaped members 2. A jack 22 is provided at the upper end of the gantry 21. Further, although not shown, a frame for preventing overturning is provided on the back side of the L-shaped member 2, and a scaffold for constructing the arch member 3 a is provided inside the L-shaped member 2.

  Next, one arch member 3 a is horizontally mounted on the side wall portion 6 of the L-shaped member 2. In order to horizontally mount the arch member 3a on the side wall portion 6 of the L-shaped member 2, as shown in FIG. 5, the wire 23 is locked in the vicinity of both ends of the arch member 3a. A chain block 24 is connected in advance to the top side wire 23a locked to the top 9 side of the arch member 3a. The wire 23 is connected to a crane (not shown), and the arch member 3a is pulled up by the crane. Next, the top wire 23a is wound up by the chain block 24, and the top 9 of the arch member 3a is lifted. By lifting the top portion 9 of the arch member 3a, the angle of the joint surface 8a of the arch member 3a provided with the connection receiving portion 12 is matched with the angle of the upper end surface 6a of the side wall portion 6 as shown in FIG. After matching the angle between the joint surface 8a of the arch member 3a provided with the joint receiving portion 12 and the upper end surface 6a of the side wall portion 6, the connecting joint 10 is inserted into the joint receiving portion 12, and the arch member 3a is attached to the base 21. Install in. At this time, since the guide member 11 is provided at the upper end of the side wall portion 6, the connection joint 10 can be easily inserted. The connection receiving portion is filled with mortar, and the arch member 3 a and the side wall portion 6 are fixed at the joint portion 8. In this way, the pair of left and right arch members 3a are connected to the L-shaped member 2 and fixed. Similarly, the joint portion 8 of the other arch member 3a is connected to the upper end 6a of the side wall portion 6 of the L-shaped member 2 and installed on the mount 21 (FIG. 4C).

  Next, the case where the pair of left and right arch members 3a are joined at the top 9 will be described. First, the jack 22 provided on the gantry 21 is moved up and down to adjust the height of the top portion 9 of one arch member 3a, and is adjusted to the height of the top portion 9 of the other arch member 3a. When the heights of the top portions 9 of both arch members 3a can be positioned, the PC steel rod 25 is inserted into the insertion hole 15 penetrating perpendicularly to the top end surface 9a, as shown in FIG. A nut 26 is screwed to both ends of the PC steel rod 25 inserted through the insertion hole 15, the nut 26 is tightened, and a tension force is introduced into the PC steel rod 25. Thereby, prestress which is tension in the left-right direction is introduced into the top 9 of the left and right arch members 3a. This prestress reaction force is absorbed by the seat surface 16 formed on the outer surface of the arch member 3a.

  Further, the same operation is repeated in the length direction of the tunnel, and when a predetermined number, for example, 10 sets of the arch members 3a are installed, they are vertically tightened in the length direction of the tunnel and integrated. Although the vertical tightening is not shown, a PC steel rod is inserted into the vertical tightening insertion hole 7 formed on the outer peripheral surface of the arch member 3a and the L-shaped member 2, and nuts are screwed onto both ends of the PC steel rod. This is done by introducing tension to the PC steel bar.

  As described above, after the L-shaped member 2 and the arch member 3a are integrated and longitudinal tightening is performed in the length direction of the tunnel, the arch reinforcing portion 3b is driven in place on the upper surface of the arch member 3a. Placing with concrete. In order to place the arch reinforcing portion 3b, a reinforcing portion mold (not shown) is placed on the upper surface of the arch member 3a. At this time, since the arch member 3a functions as a part of the reinforcing part mold, the amount of the mold member carried into the site can be reduced as compared with the case where the entire arch part 3 is formed of the cast-in-place concrete. At the same time, it is possible to reduce the cost of installing the mold and reducing the number of work steps for dismantling. In addition, the arch member 3a can be reduced in size compared with the case where the arch member 3a is integrated with the arch reinforcing portion 3b in advance, so that the transportation cost can be reduced and the connection work to the L-shaped member 2 is simplified. can do.

  Next, the case where the center bottom slab part 4 is laid by the cast-in-place concrete on the tunnel member installed at the site will be described. The center bottom plate portion 4 is composed of a reinforcing bar (not shown) arranged between the bottom portions 5 of the L-shaped member 2 and a cast-in-place concrete, and the reinforcing bars and the reinforcing bars formed in advance on the bottom portion 5 are formed. They are connected by a mechanical joint (not shown). Various mechanical joints are conceivable. For example, although not shown in the drawings, the embedding sleeve is fixed to the reinforcing bar provided on the bottom 5 of the L-shaped member 2, and the connecting sleeve is fixed to the reinforcing bar at the end constituting the central bottom plate portion 4. Either a right female screw or a left female screw is formed so as to be paired with the sleeve, and the connection can be established by fixing with a connection bolt having a right screw at one end and a left screw at the other end. In this way, the concrete is cast between the bottom portions 5 of the L-shaped member 2 to which the reinforcing bars are joined to form the central bottom plate portion 4 (FIG. 4D). After the above work is completed, the framework and scaffolding are dismantled and removed.

  As described above, the tunnel structure 1 according to the present embodiment is constituted by a plurality of divided precast concrete members, so that installation and dismantling of the formwork are unnecessary as compared with a case where the tunnel structure 1 is constructed by on-site concrete. The work man-hours can be greatly reduced and the cost can be greatly reduced. In addition, since the tunnel structure 1 is constituted by four parts, it can be easily formed in a factory and can be easily transported.

  In addition, when the ground G is soft, it is necessary to provide the center bottom plate | board part 4 between the bottom parts 5 of the L-shaped member 2 as mentioned above, but for the strong ground G, it shows in FIG. The back bottom plate portion 30 can be applied as such a bottom plate portion. The back bottom plate portion 30 is formed on the back surface of the L-shaped member 2 by cast-in-place concrete. Thereby, since the amount of members to be used can be reduced as compared with the central bottom plate portion 4, the cost can be reduced while maintaining a sufficient strength.

  The tunnel structure 1 having a large cross section constructed as described above absorbs the pre-stressed PC steel rod 25 and the arch reinforcing portion 3b when a moment due to earth pressure or the like is generated in the arch member 3a and the side wall portion 6. Further, in the tunnel structure 1 according to the present embodiment, stress concentrates on a location where the side wall portion 6 and the bottom portion 5 of the L-shaped member 2 are connected. As described above, the L-shaped member 2 has the side wall portion 6 and the bottom portion 5. Can be ensured sufficient strength against stress. As described above, the tunnel structure 1 has a structure capable of absorbing each stress. Therefore, the tunnel structure 1 has a large cross section and is made of a plurality of precast concrete members, but ensures sufficient strength. Can do.

  As described above, in the present embodiment, in the tunnel structure 1 including the arch portion 3 curved in an arch shape, the arch portion 3 is formed on the arch member 3a by precast concrete arch member 3a and cast-in-place concrete. By being formed by the arch reinforcing portion 3b formed in the above, it is possible to reduce the cost by reducing the number of on-site work steps even with a large cross section. In addition, by forming the arch reinforcing part 3b with cast-in-place concrete, the arch member 3a functions as a part of the mold for forming the arch reinforcing part 3b. The number of work steps for installing and dismantling the frame can be reduced, and the cost can be further reduced.

  Further, since the arch member 3a is divided into left and right at the top portion 9, it is easy to transport and can be constructed with a member made of precast concrete even if it is a tunnel having a large cross section. Can be reduced.

  Further, since the arch member 3a includes the embedded body 17, the arch member 3a can be reduced in weight, the material cost and the transportation cost can be reduced, and the field work can be easily performed, so the cost can be further reduced. be able to.

  The arch member 3 is horizontally mounted between a pair of left and right precast concrete L-shaped members 2 extending in the tunnel height direction from the tunnel bottom side portion, and a central bottom plate portion 4 is interposed between the L-shaped members 2. By providing, since the side wall was comprised with the L-shaped member 2, a side wall can become independent, and it can install easily and can reduce work man-hours. Moreover, it can be reliably constructed even in the soft ground G.

  The arch member 3 is laid between a pair of left and right precast concrete L-shaped members 2 extending in the tunnel height direction from the tunnel bottom side, and a rear bottom plate portion 30 is provided on the back of the L-shaped member 2. By providing, since the side wall was comprised with the L-shaped member 2, a side wall can become independent, and it can install easily and can reduce work man-hours. Moreover, since it can build with few materials, cost can be reduced.

  Further, a pair of left and right precast concrete L-shaped members 2 extending in the tunnel height direction from the bottom side of the tunnel are installed, the arch member 3a according to claim 2 is horizontally mounted, and the L-shaped member 2 and the By fastening the arch member 3a and fastening the arch members 3a to each other with a PC steel rod introduced with a tension force at the top 9, and forming the arch reinforcing portion 3b on the upper surface of the arch member 3a by using cast-in-place concrete, Even a tunnel having a large inner space can be constructed with a precast concrete member, so the cost can be reduced. Further, by forming the arch reinforcing portion 3b with cast-in-place concrete, the arch member 3a can function as a part of the mold for forming the arch reinforcing portion 3b, so the amount of the mold member is reduced. At the same time, it is possible to reduce the work man-hours for installing and dismantling the formwork, thereby further reducing the cost.

  In addition, a pair of left and right precast concrete L-shaped members 2 extending in the tunnel height direction from the bottom side of the tunnel is installed, the pair of L-shaped members 2 are connected to each other by a spacing member 27, and the arch member 3a is laterally moved. The L-shaped member 2 and the arch member 3a are fastened together, and the arch members 3a are fastened to each other by a PC steel rod introduced with a tension force at the top 9, and then the spacing member 27 is removed, By forming the arch reinforcing part 3b with concrete on the upper surface of the arch member 3a, the pair of left and right L-shaped members 2 are connected to each other by the spacing member 27, so that the L-shaped member 2 is prevented from falling during construction. it can. Moreover, since it can hold | maintain at a predetermined space | interval and a tunnel of a large section can be constructed | assembled safely and easily, cost can be reduced.

  Further, in this embodiment, the case where the ceiling of the tunnel is closed with the arch member 3a has been described. However, the present invention is not limited to this, and the arch member 3a2 provided with the oblique cuts 31 as shown in FIG. 2 may be connected. By doing so, it is also possible to form a light source at the tunnel exit.

  Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected about the structure similar to the structure which concerns on the above-mentioned 1st Example, and description is abbreviate | omitted for simplicity.

  The tunnel structure 35 according to the present embodiment shown in FIG. 8 differs from the tunnel structure 1 according to the first embodiment only in the arch portion 36, and is horizontally mounted between a pair of L-shaped members 2 and the L-shaped members 2. The arch portion 36 is formed. The arch part 36 is formed by an integrated arch member 36a made of precast concrete and an arch reinforcing part 36b formed of cast-in-place concrete. That is, the integrated arch member 36a according to the present embodiment is a rectangular plate member having substantially the same thickness as the side wall portion 6 formed by being curved in the width direction of the tunnel so as to protrude upward. , Previously formed at the factory. The contact portion 37 between the integral arch member 36a and the L-shaped member 2 is formed with an insertion hole (not shown) penetrating perpendicularly to the contact surface.

  Next, a method for constructing the tunnel structure 1 will be described with reference to FIG. First, as shown in FIG. 9 (A), a foundation 20 is laid on the ground G that has been cut by using leveled concrete. Next, after laying mortar (not shown) on the foundation 20, the L-shaped member 2 is installed as a pair of left and right (FIG. 9B).

  Next, as shown in FIG. 9 (C), a movable base 21 is installed approximately in the middle of the pair of L-shaped members 2. Further, although not shown, a frame for preventing overturning is provided on the back side of the L-shaped member 2, and a scaffold for constructing the arch portion 36 is provided inside the L-shaped member 2. Moreover, the center bottom plate | version | printing part 4 is driven in the said tunnel member installed in the field. The center bottom plate portion 4 is composed of a reinforcing bar (not shown) arranged between the bottom portions 5 of the L-shaped member 2 and a cast-in-place concrete, and the reinforcing bars and the reinforcing bars formed in advance on the bottom portion 5 are formed. They are connected by a mechanical joint (not shown).

  Next, the integral arch member 36 a is horizontally mounted on the side wall portion 6 of the L-shaped member 2. That is, as shown in FIG. 9D, the wire 23 is locked in the vicinity of both ends of the integrated arch member 36a. A chain block 24 is connected to the wire 23 in advance. The wire 23 is connected to a crane (not shown), and the integrated arch member 36a is pulled up by the crane. Next, the position of the integrated arch member 36a is finely adjusted by adjusting the length of the wire 23 by the chain block 24, and the integrated arch member 36a is formed into an L-shaped member by the fastening PC steel rod inserted through the insertion hole. Connect to 2. Each time one set of the integrated arch member 36a is installed, the joint is filled with mortar, and the integrated arch member 36a and the side wall 6 are fixed.

  In this way, the same operation is repeated in the length direction of the tunnel, and when a predetermined number of, for example, two sets of integrated arch members 36a are installed, they are vertically tightened in the length direction of the tunnel and integrated.

  As described above, after the L-shaped member 2 and the integrated arch member 36a are integrated, and the vertical tightening is performed in the length direction of the tunnel, the arch reinforcing portion is formed on the upper surface of the integrated arch member 36a. 36b is cast in place. After completion of the work, dismantle and remove the framework and scaffolding.

  Needless to say, the L-shaped member 2 may be connected by the spacing member 27.

  As described above, since the arch portion 3 is constituted by the integral arch member 3a and the arch reinforcing portion 3b, the number of members can be reduced, so that the number of work steps can be reduced and the cost can be reduced.

  The present invention is not limited to this embodiment, and various modifications can be made within the scope of the gist of the present invention.

  Moreover, although this embodiment demonstrated the tunnel structure 1 in the open-cut method, this invention is not restricted to this, It can also be applied as an arch bridge.

It is a longitudinal cross-sectional view which shows the tunnel structure of the large cross section based on this embodiment. It is a longitudinal cross-sectional view which shows the junction part of a side wall part and an arch member same as the above. It is a longitudinal cross-sectional view of a top part same as the above. It is a figure which shows the construction method of the tunnel of a large section concerning this embodiment in steps. It is a figure which shows the state which installs an arch member same as the above. It is a longitudinal cross-sectional view which shows the modification of this embodiment. It is an external view which shows another modification of this embodiment. It is a longitudinal cross-sectional view which shows the tunnel structure based on 2nd Example of this invention. It is a figure which shows the construction method of a tunnel step by step same as the above.

Explanation of symbols

1 Tunnel structure 2 L-shaped member 3 Arch part
3a Arch member
3b Arch reinforcement part 4 Center bottom plate part 9 Top part
17 Embedded

Claims (7)

In a tunnel structure including an arch portion curved in an arch shape, the arch portion is formed by an arch member made of precast concrete and an arch reinforcing portion formed on the arch member by cast-in-place concrete. A large-section tunnel structure. The large-section tunnel structure according to claim 1, wherein the arch member is divided into left and right at the top. The large-section tunnel structure according to claim 1, wherein the arch member includes a void. The arch member is horizontally mounted between a pair of left and right precast concrete L-shaped members extending in a tunnel height direction from a tunnel bottom side portion, and a center bottom plate portion is provided between the L-shaped members. The large-sized tunnel structure of any one of 1-3. The arch member is horizontally mounted between a pair of left and right precast concrete L-shaped members extending in a tunnel height direction from a tunnel bottom side portion, and a back bottom plate portion is provided on a back surface of the L-shaped member. Item 4. The tunnel structure according to any one of Items 1 to 3. A pair of left and right precast concrete L-shaped members extending in the tunnel height direction from the bottom side of the tunnel is installed, the arch member is horizontally mounted, the L-shaped member and the arch member are fastened, and the arch is formed by cast-in-place concrete A method for constructing a tunnel structure having a large cross section, wherein a reinforcing portion is formed on an upper surface of the arch member. A pair of left and right precast concrete L-shaped members extending in the tunnel height direction from the tunnel bottom side is installed, the pair of L-shaped members are connected to each other by a spacing member, an arch member is horizontally mounted, and the L-shaped A method for constructing a tunnel structure with a large cross section, comprising: fastening a member and the arch member; then removing the spacing member; and forming an arch reinforcing portion on an upper surface of the arch member by cast-in-place concrete.

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