JP6776603B2 - How to build tunnel lining concrete and lining concrete - Google Patents

Description

The present invention relates to a tunnel lining concrete in which a joint portion is formed at a joint portion and a method for constructing the lining concrete.

Conventionally, when constructing lining concrete in a tunnel, a tunnel lining concrete steel formwork (slide center) is placed facing the inner wall surface of the tunnel, and concrete is placed between the two to form the concrete. After the tunnel has hardened, the tunnel lining concrete steel formwork is moved along the axis of the tunnel. This process is repeated in sequence to splice concrete in the axial direction of the tunnel to construct lining concrete.

Under such circumstances, for example, as shown in FIG. 12, Patent Document 1 installs a formwork 201 having a trapezoidal joint material 202 on the face side of the existing concrete 205, and then installs the formwork 201 and the inner wall surface of the tunnel. A method is disclosed in which fresh concrete is placed between 203 and lining concrete 20 is constructed while forming joints 207 at the joint 206 between the joined concrete 204 and the existing concrete 205.

Japanese Unexamined Patent Publication No. 2003-278496

However, since the joint 207 is formed in a trapezoidal shape, the corner portion C is formed around the joint portion 207. Therefore, not only the slag containing bleeding water or the like is likely to accumulate in the corner portion C, but also the concrete filling is defective. It tends to occur and become a porous vulnerable part.

Further, in the construction work of the lining concrete 20, the formwork 201 is demolded, moved, and installed when the strength of the succeeded concrete 204 is not completely developed at a weak age. Therefore, when an unbalanced load when removing the formwork 201 or a pushing-up load when installing the formwork 201 acts on the corners C located at both ends of the lower side of the joint 207, the corners C are cracked due to stress concentration. Damage such as chipping and chipping is likely to occur.

Furthermore, even after the construction of the lining concrete 20, the lining concrete 20 expands and contracts due to seasonal changes in temperature and humidity, so that the corners of the existing concrete 205 located on the upper side of the joint 207 C is prone to chipping due to interference or adhesion.

The present invention has been made in view of the above problems, and a main object thereof is a method for constructing lining concrete and lining concrete for a tunnel, which is less likely to be damaged even if various external forces act on the lining concrete. Is to provide.

In order to achieve such an object, the tunnel lining concrete of the present invention is formed by sequentially joining concrete in the axial direction with respect to the inner wall surface of the tunnel, and the lining of the tunnel having a joint portion at the joint portion. In concrete, the joint portion is formed by chamfered portions provided on the inner edge of the joint surface of the existing concrete and the inner edge of the facing surface of the new concrete facing the joint surface, respectively , and the facing surface of the new concrete. The chamfered portion formed on the inner edge of the concrete is composed of an arc that is convex toward the inner space of the tunnel, and the chamfered portion formed on the inner edge of the joint surface of the existing concrete is the inner peripheral surface of the existing concrete and the above. It consists of an arc that is smoothly continuous in the direction connecting the joint surface and is convex toward the air inside the two tunnels with different curvatures. Of the two arcs with different curvatures, the arc adjacent to the joint surface It is characterized by a small curvature of.

According to the tunnel lining concrete of the present invention described above, since curved chamfered portions are formed on both the inner edge of the joint surface of the existing concrete and the inner edge of the facing surface of the new concrete, the lining after construction. It is possible to make concrete a sound structure with high durability, which is filled with concrete in every corner.

In addition, there is a concern that the joint surface of the existing concrete located at the top of the joint and the facing surface of the new concrete may have corners of a size that may cause slag accumulation or poor concrete filling, or poor concrete placement. There is no vulnerable part. As a result, due to seasonal changes in temperature and humidity, volume changes such as expansion and drying shrinkage occur in the lining concrete after construction, and interference occurs between the joint surface of the existing concrete and the facing surface of the new concrete. It is possible to prevent cracks and chips from occurring in the vicinity of the top of the joint even when a tensile force is applied.

Further, similarly to the top of the joint, there are no corners having a size such as slag accumulation or poor concrete filling at both ends of the bottom of the joint, or fragile parts where there is a concern about poor concrete placement. As a result, even if various external forces act on the inner peripheral surface of the lining concrete after construction, it is possible to prevent damage such as cracks and peeling that are likely to occur in the vicinity of the joint portion.

Further, of the two arcs connecting the inner peripheral surface and the joint surface of the existing concrete, the curvature of the arc adjacent to the joint surface is reduced to form a gentle curved surface. As a result, when performing joint work of lining concrete, if a material with elastic deformation performance is adopted for the formwork for forming joints and a pushing force is applied from below, the formwork will have a gentle curved surface. Elastic deformation occurs in the height direction while being guided away from the joint surface. For this reason, even if the existing concrete has an incomplete strength development at a weak age, it is possible to reliably adhere the formwork to the existing concrete while suppressing damage to the contact portion with the formwork. Become.

In the method for constructing the lining concrete of the tunnel of the present invention, while moving the tunnel lining steel formwork in the axial direction of the tunnel, concrete is sequentially joined to the inner wall surface of the tunnel to form the lining concrete of the tunnel of the present invention. A method for constructing lining concrete to be constructed, for forming a chamfered portion having a curved surface on the inner edge of the facing surface of the newly constructed concrete on the wellhead side of a dam provided in the tunnel lining steel formwork. A chamfered portion provided with a flexible groove formwork having a concrete casting surface and a curved surface at the inner edge of an end surface parallel to the facing surface of the newly constructed concrete in a wife frame provided in the tunnel lining steel formwork. established a rigid grooved mold for forming, the tunnel lining steel mold, so that the wellhead side of the flexible groove formwork abuts against the chamfered portion of the existing concrete, which install, the The flexible groove form is made of a member that undergoes elastic deformation, and the rigid groove form is made of a steel material. Further, the height of the flexible groove form is formed lower than the height of the rigid groove form.

According to the method for constructing lining concrete of the present invention described above, the chamfered portion has a curved surface even when an excessive pushing force is applied when installing the flexible groove formwork on the chamfered portion of the existing concrete. Therefore, it is possible to prevent cracks due to stress concentration that are likely to occur in the vicinity of the joint portion of the existing concrete.

In addition, when the flexible groove formwork and the rigid groove formwork are removed when the strength of the existing concrete and the new concrete is not completely developed, the tunnel lining steel formwork is unevenly jacked down, etc. As a result, even if a complicated external force acts on the chamfered part of the existing concrete and the new concrete, the chamfered part has a curved surface, so that it is possible to prevent chipping and peeling that are likely to occur near the joint part of the existing concrete and the new concrete. It will be possible.

In this way, with a simple configuration in which the flexible groove formwork and the rigid groove formwork are simply installed on the dam of the tunnel lining steel formwork, the tunnel lining steel formwork can be installed or removed. Due to the formwork work, it is possible to prevent cracks and chips that are likely to occur near the joints of the existing concrete and the new concrete.

According to the present invention, by forming curved chamfered portions on both the inner edge of the joint surface of the existing concrete and the inner edge of the facing surface of the new concrete, a fragile portion exists in the joint portion formed in the joint portion. Therefore, even if various external forces act on the lining concrete, it is possible to prevent damage such as cracks and peeling in the vicinity of the joint portion.

It is a figure which shows the joint part of the lining concrete of the tunnel of this invention. It is a figure which shows the detail of the joint part formed in the joint part of this invention. It is a figure which shows the state which installed the tunnel lining concrete steel formwork device of this invention. It is a figure which shows the tunnel lining concrete steel formwork device seen from the direction of the tunnel axis of this invention. It is a figure which shows the flexible groove form and the rigid groove form main body of this invention. It is a figure which shows the state which the tunnel lining steel formwork of this invention was demolded. It is a figure which shows the cross section of the flexible groove form and the rigid groove form of this invention. It is a figure which shows the state which installed the flexible groove formwork on the existing concrete of this invention. It is a figure which shows the groove form for the first time of this invention. It is a figure which shows another example of the steel groove form of this invention. It is a figure which shows the chamfered part of the curved surface shape formed by the steel groove form of another example of this invention. It is a figure which shows the joint formed in the lining concrete of the conventional tunnel.

As shown in FIG. 1, which shows a cross section parallel to the axis of the tunnel 15, the lining concrete 1 covering the inner wall surface 151 of the tunnel is the hardened concrete (hereinafter, existing concrete) after the fresh concrete placed in advance has hardened. The process of constructing new concrete (hereinafter referred to as new concrete 3) by placing fresh concrete afterwards so as to be connected to the joint surface 21 of concrete 2) and hardening it. It is constructed by sequentially repeating in the axial direction of the tunnel 15, and a joint portion 5 is formed in these joint portions 4.

As shown in an enlarged view in FIG. 2, the joint portion 5 is an inner edge of each of the joint surface 21 of the existing concrete 2 and the facing surface 31 of the new concrete 3 facing the joint surface 21 on the side of the empty portion 152 in the tunnel. It is located in the region surrounded by the chamfered portions 22 and 32 formed in, and all of these chamfered portions 22 and 32 are formed on a convex curved surface.

Specifically, the chamfered portion 22 of the existing concrete 2 is formed in a shape forming a continuous single-core circular arc so as to connect the inner peripheral surface 23 of the existing concrete 2 and the joint surface 21. On the other hand, the chamfered portion 32 of the new concrete 3 is formed so as to form a so-called ginkgo surface, which forms a single-core circular arc connecting the inner peripheral surface 33 of the new concrete 3 and the facing surface 31 via the step portion S. Has been done.

In the present embodiment, the chamfered portion 22 of the existing concrete 2 and the chamfered portion 32 of the new concrete 3 are both formed by a single-core circular arc having the same curvature. However, the present invention is not necessarily limited to this, and each may be formed by arcs having different curvatures, and the chamfered portions 22 and 32 are formed as long as they form a convex curved surface. , An ellipse, or any other curved surface.

Further, in the present embodiment, the chamfered portion 32 of the newly installed concrete 3 is formed in a shape having stepped portions S at both ends of the arc of a single core circle, but the present invention is not necessarily limited to this, and both ends. Both portions may have a shape without a step portion S, or may be formed so as to have a so-called single ginkgo surface in which the step portion S is provided only at the end of the arc located on the inner wall surface 151 side of the tunnel.

The step portion S is a very minute step generated when a mold made of a flexible material such as hard rubber is used, and the corner portion formed in the step portion S is bleeding at the time of placing fresh concrete. It is not a size that causes construction defects such as accumulation of rubber containing water or poor concrete filling, and it is not a corner that becomes a fragile part.

According to the above-mentioned lining concrete 1, curved surface-shaped chamfered portions 22 and 32 as shown in FIG. 2 are provided on both the inner edge of the joint surface 21 of the existing concrete 2 and the inner edge of the facing surface 31 of the new concrete 3. Since it is formed, the hardened lining concrete 1 can have a sound structure with high durability filled with concrete in every corner.

Further, although the stepped portion S exists on the joint surface 21 of the existing concrete 2 and the facing surface 31 of the new concrete 3 located at the top of the joint portion 5 as shown in FIG. 2, these are fragile as described above. There are no other vulnerable parts, not just the corners. As a result, the lining concrete 1 after construction undergoes volume changes such as expansion and drying shrinkage due to seasonal changes in temperature and humidity, and the joint surface 21 of the existing concrete 2 and the facing surface 31 of the new concrete 3 It is possible to prevent cracks and chips from being generated in the lining concrete 1 even when interference or tensile force acts between them.

Further, as shown in FIG. 2, fragile corners and fragile corners are formed on the joint surface 21 of the existing concrete 2 and the facing surface 31 of the new concrete 3 located at both ends of the bottom of the joint portion 5 as well as the top of the joint portion 5. There are no other vulnerable parts. As a result, even if various external forces act on the inner peripheral surfaces 23 and 33 of the lining concrete 1 after construction, it is possible to prevent damage such as cracks and peeling that are likely to occur in the vicinity of the joint portion 5.

For the construction of such a lining concrete 1, a tunnel lining concrete steel formwork device 6 as shown in FIGS. 3 and 4 is adopted. The tunnel lining concrete steel formwork device 6 includes a gantry 7 that can move in the axial direction of the tunnel 15, a tunnel lining steel formwork 8 supported by the gantry 7, and a tunnel lining steel formwork 8. It is provided with a wife frame 9 installed at the end on the face side.

The tunnel lining steel formwork 8 has a weir plate 81 formed in a shape that covers the tunnel inner wall surface 151 with a predetermined interval A as shown in FIG. 4, and a weir plate 81 as shown in FIG. An overlap flange 82 which is installed at the end on the tunnel entrance side and whose upper surface forms the same plane as the weir 81 is provided, and the flexible groove formwork 10 and the rigid groove form 12 are installed on the weir 81, respectively. ing.

As shown in FIG. 5A, the flexible groove formwork 10 is made of a long body having a substantially triangular cross section, and is made of a flexible material such as hard rubber having flexibility. The flexible material has a strength that does not deform due to the lateral pressure of the fresh concrete placed between the dam 81 and the inner wall surface 151 of the tunnel. Further, the flexible groove formwork 10 has a hollow portion 104 communicating in the longitudinal direction, and a flat installation surface 101 for installation on the weir 81 is continuously formed on the bottom surface in the longitudinal direction. ..

In order to install the flexible groove formwork 10 having such a configuration on the tunnel lining steel formwork 8, the longitudinal direction is orthogonal to the axial direction of the tunnel 15 as shown in FIGS. 3 and 4. The installation surface 101 is arranged so as to straddle both the weir plate 81 and the overlap flange 82, and is fixed via a binding means such as a wire inserted through the hollow portion 104. As a result, the flexible groove formwork 10 can be detachably installed along the weir plate 81.

As shown in FIG. 6, the flexible groove formwork 10 installed in this way is arranged so that one hypotenuse having a substantially triangular shape in cross-sectional view is on the wellhead side and the other hypotenuse is on the face side. Then, on one of the hypotenuses on the wellhead side, contact surfaces 102 having a shape of contacting the chamfered portion 22 on the joint surface 21 of the existing concrete 2 are continuously formed in the longitudinal direction. Further, on the other hypotenuse on the face side, a concrete placing surface 103 for forming a chamfered portion 32 on the facing surface 31 of the new concrete 3 is formed.

Here, as shown in FIG. 2, both the chamfered portion 22 of the existing concrete 2 and the chamfered portion 32 of the new concrete have a single arc as a curved surface, and in the present embodiment, an arc having a radius of 60 mm. Is adopted. Therefore, the contact surface 102 and the concrete placing surface 103 provided in the flexible groove formwork 10 are also formed in a concave arc having a radius of 60 mm, as shown in FIG. 7A.

On the other hand, as shown in FIG. 7B, the rigid groove form 12 is composed of a rigid groove form main body 13 and a groove form fixing plate 14. The rigid groove formwork body 13 is made of a long body formed of a rigid material such as steel and having a substantially right triangle in cross section, and is a weir plate when the longitudinal direction is arranged in a direction orthogonal to the axis of the tunnel 15. As shown in FIG. 5B, the longitudinal direction is formed in a curved shape along 81. The bottom surface of the rigid groove formwork 12 is formed on a flat installation surface 131 so that it can be installed on the weir plate 81.

As shown in FIG. 6, the rigid groove formwork body 13 whose longitudinal direction is orthogonal to the axis of the tunnel 15 has a substantially right-angled triangular hypotenuse facing the wellhead side and the opposite side facing the face side, as shown in FIG. Arranged like this. Then, on the hypotenuse on the wellhead side, a concrete placing surface 132 for forming a chamfered portion 35 on the inner edge of the end surface 34 parallel to the facing surface 31 of the new concrete 3 is continuously formed in the longitudinal direction.

Further, on the opposite side on the face side, a mounting surface 133 for mounting on the groove form fixing plate 14 is continuously formed in the longitudinal direction. The groove formwork fixing plate 14 is a plate-like member which is an end surface on the face side of the tunnel lining steel formwork 8 as shown in FIG. 3 and is joined and arranged to the end frame 9, and the plate surface is the end face of the end frame 9. It is erected so as to be parallel, and its upper end is above the dam 81 of the tunnel lining steel formwork 8 and is located at an intermediate height of the end frame 9.

Further, as shown in FIG. 7B, the groove formwork fixing plate 14 is provided with a concrete placement surface 141 continuous with the concrete placement surface 132 of the rigid groove formwork main body 13, and the concrete placement surface 141 is provided. The upper end of the surface 141 has a shape that sticks to the end plate 9. As a result, as shown in FIG. 3, the weir plate 81 and the end frame 9 are smoothly formed via the concrete casting surface 132 of the rigid groove formwork body 13 and the concrete casting surface 141 of the groove formwork fixing plate 14. It has a continuous shape.

The end surface 34 of the new concrete 3 naturally has the same shape as the joint surface 21 of the existing concrete 2. Further, in the present embodiment, since the chamfered portion 22 provided on the joint surface 21 of the existing concrete 2 is formed in a single circular arc having a radius of 60 mm, the chamfered portion 35 formed on the inner edge of the end surface 34 is also formed. As shown in FIG. 7B, both the concrete placing surface 132 of the rigid groove form main body 13 and the concrete placing surface 141 of the groove form fixing plate 14 are formed in a single circular arc having a radius of 60 mm. , Is formed in a concave arc with a radius of 60 mm.

The procedure for constructing the lining concrete 1 by using the tunnel lining steel formwork 8 in which the flexible groove formwork 10 and the rigid groove formwork 12 having the above-described configuration are installed is as follows.

First, the tunnel lining concrete steel formwork device 6 is moved in the axial direction of the tunnel 15 via the gantry 7, and as shown in FIG. 3, the contact surface 102 of the flexible groove formwork 10 is the existing concrete 2. The tunnel lining steel formwork 8 is installed by abutting on the chamfered portion 22 formed on the joint surface 21 of the above and providing a predetermined distance A between the weir plate 81 and the inner wall surface 151 of the tunnel.

Next, fresh concrete is cast between the dam 81 and the inner wall surface 151 of the tunnel, and the joint surface 21 of the existing concrete 2 is joined, and this is hardened to construct the new concrete 3. After that, as shown in FIG. 6, the tunnel lining steel formwork 8 is removed from the new concrete 3 and moved to the front of the new concrete 3 on the face side via the gantry 7.

By repeating this procedure sequentially from the wellhead side toward the face direction, a joint portion 5 surrounded by two chamfered portions 22 and 32 is formed at the joint portion 4 of the existing concrete 2 and the new concrete 3. The work concrete 1 is constructed.

In the present embodiment, as shown in FIG. 7, the height L1 of the flexible groove formwork 10 is set lower than the height L2 of the rigid groove formwork 12. By doing so, when the tunnel lining steel formwork 8 is installed, the flexible groove formwork 10 can be efficiently brought into close contact with the chamfered portion 22 of the existing concrete 2.

That is, as shown in FIG. 6, the newly constructed concrete 3 in which the chamfered portion 35 is formed on the inner edge by the concrete placing surfaces 132 and 141 of the rigid groove formwork 12 is shown when the fresh concrete is subsequently laid. It becomes the existing concrete 2 as shown in 3, and the chamfered portion 35 of the new concrete 3 becomes the chamfered portion 22 of the existing concrete 2. At this time, as shown in FIG. 8, the curved surface-shaped chamfered portion 22 of the existing concrete 2 is formed from the inner peripheral surface 23 of the existing concrete 2 to the height of L2.

Therefore, in order to install the tunnel lining steel formwork 8, when the contact surface 102 of the flexible groove formwork 10 is brought into contact with the chamfered portion 22 of the existing concrete 2, as shown in FIG. Even if the flexible groove formwork 10 is elastically deformed so that the height becomes higher than L1 due to the pushing force, the entire length of the contact surface 102 is brought into contact with the chamfered portion 22 of the existing concrete 2. Can be done.

The shapes of the flexible groove formwork 10 and the rigid groove formwork 12 are not necessarily limited to this, and the height L1 of the flexible groove formwork 10 and the height L2 of the rigid groove formwork 12 May be formed to have the same height. Further, the top of the flexible groove form 10 may also be treated so as to have an acute angle, but if the top is notched as shown in FIG. 7A, the cover after demolding may be formed. It is possible to reliably prevent the residue of the flexible groove formwork 10 from being generated in the work concrete 1.

By the way, in the method of constructing the lining concrete 1, since the existing concrete 2 does not exist at the time of placing the fresh concrete for the first time, the first groove form 11 is attached to the weir 81 instead of the flexible groove form 10. , Start placing fresh concrete. As shown in FIG. 9, the initial groove form 11 is made of a long body having a substantially right triangle in cross section, and is made of a hard material such as polyethylene. Any hard material may be used as long as it has a rigidity that does not deform due to the lateral pressure when the fresh concrete is placed between the dam 81 and the inner wall surface 151 of the tunnel. Good.

Further, the initial groove form 11 is formed in a curved shape in the longitudinal direction so as to be along the upper surface of the weir 81 when the longitudinal direction is arranged in the direction orthogonal to the axis of the tunnel 15. Flat installation surfaces 111 for installation on the weir plate 81 are continuously formed in the length direction. Such an initial groove form 11 is arranged so that the hypotenuse having a substantially right-angled triangle shape is on the face side and the opposite side is on the wellhead side in cross-sectional view.

Then, the concrete placing surface 112 is continuously formed in the longitudinal direction on the hypotenuse on the face side. In the present embodiment, since the chamfered portion 32 of the new concrete 3 uses a single circular arc with a radius of 60 mm, the concrete placing surface 112 of the initial groove form 11 is formed into a concave arc with a radius of 60 mm. ing. Further, on the opposite sides of the wellhead side and the face side, a mounting surface 113 for mounting on the end frame 9 installed at the wellhead side end of the tunnel lining steel formwork 8 is formed.

Therefore, at the time of the first casting work, as shown in FIG. 9, the end frame 9 is installed at the wellhead side end of the tunnel lining steel formwork 8 and the groove formwork 11 for the first time is installed on the weir 81. Place fresh concrete. After demolding, the end frame 9 and the initial groove formwork 11 are removed, and as shown in FIG. 3, the overlap flange 82 and the flexible groove formwork 10 are installed on the tunnel lining steel formwork 8. Subsequent work may be performed.

According to such a method for constructing the lining concrete 1, when the tunnel lining steel formwork 8 is installed, an excessive pushing force acts from the flexible groove formwork 10 to the chamfered portion 22 of the existing concrete 2. Even in this case, since the chamfered portion 22 has a curved surface shape, it is possible to prevent the existing concrete 2 from being cracked due to stress concentration.

Further, when the flexible groove formwork 10 and the rigid groove formwork 12 are removed from the existing concrete 2 and the new concrete 3 at a weak age when the strength is not completely developed, the tunnel lining steel formwork 8 is not used. Even if a complicated external force acts on the chamfered portions 22 and 32 of the existing concrete 2 and the new concrete 3 due to uniform jacking down or the like, since these chamfered portions 22 and 32 have curved surfaces, the existing concrete 2 and the new concrete are installed. It is possible to prevent the 3 from being chipped or peeled off.

In this way, the tunnel lining steel formwork 8 can be installed with a simple configuration in which the flexible groove formwork 10 and the rigid groove formwork 12 are simply installed on the dam 81 of the tunnel lining steel formwork 8. It is possible to prevent cracks and chips that are likely to occur in the vicinity of the joint portion 5 of the existing concrete 2 and the new concrete 3 due to the formwork work such as demolding.

It should be noted that the method for constructing the lining concrete 1 and the lining concrete 1 of the present invention is not limited to the above embodiment, and it goes without saying that various changes can be made without departing from the gist of the present invention. Nor.

For example, in the present embodiment, concave arcs having the same diameter are formed on the concrete placing surfaces 132 and 141 of the rigid groove formwork 12 and are continuous, but concave arcs having different radii are formed in each of them. It may be a continuous configuration. Specifically, as shown in FIG. 10, a concave arc having a radius of 140 mm is provided on the concrete placing surface 141 of the groove formwork fixing plate 14, and a radius of 60 mm is provided on the concrete placing surface 132 of the rigid groove formwork body 13. A concave arc is provided and made continuous.

Then, as shown in FIG. 11, the chamfered portion 22 of the existing concrete 2 has two arcs C1 having different curvatures that are smoothly continuous in the direction of connecting the inner peripheral surface 23 and the joint surface 21 of the existing concrete 2. , C2 is formed. At this time, by making the curvature of the arc C1 adjacent to the joint surface 21 smaller than the curvature of the arc C2 adjacent to the inner peripheral surface 23, the chamfered portion 22 of the existing concrete 2 faces the joint surface 21 from the inner peripheral surface 23. The curved surface gradually rises.

As a result, when the contact surface 102 of the flexible groove formwork 10 is brought into contact with the chamfered portion 22 of the existing concrete 2 in order to install the tunnel lining steel formwork 8, a pushing force acts from below. The flexible groove formwork 10 is guided toward the face side by a curved surface formed of a gentle arc C1, and elastically deforms so that the height becomes higher than L1. For this reason, even if the existing concrete 2 is of a weak material age in which the strength development is not perfect, the flexible groove is prevented from being damaged in the vicinity of the chamfered portion 22 in contact with the flexible groove formwork 10. The entire length of the contact surface 102 of the mold 10 can be more reliably brought into close contact with the chamfered portion 22.

1 Lining concrete 2 Existing concrete 21 Joint surface 22 Chamfered part 23 Inner peripheral surface 3 New concrete 31 Facing surface 32 Chamfered part 33 Inner peripheral surface 4 Jointed part 5 Joint part 6 Tunnel lining Concrete steel mold frame device 7 Guntry 8 Tunnel lining Steel mold 81 Damping plate 82 Overlap flange 9 End frame 10 Flexible groove mold 101 Installation surface 102 Contact surface 103 Concrete casting surface 104 Hollow part 11 Initial groove mold 12 Rigid groove type Frame 13 Rigid groove type frame body 131 Installation surface 132 Concrete placement surface 133 Mounting surface 14 Groove type frame fixing plate 141 Concrete placement surface 15 Tunnel 151 Tunnel inner wall surface 152 Tunnel inner wall surface 20 Tunnel interior space 20 Lining concrete 201 Form 202 joint material 203 Inner wall surface of tunnel 204 New concrete 205 Existing concrete 206 Joint part 207 Joint part C Corner part S Step part A Interval

Claims (3)

A tunnel lining concrete formed by sequentially joining concrete in the axial direction with respect to the inner wall surface of the tunnel and having joints at the joints.
The joint portion is formed by a chamfered portion provided on the inner edge of the joint surface of the existing concrete and the inner edge of the facing surface of the new concrete facing the joint surface.
The chamfered portion formed on the inner edge of the facing surface of the newly constructed concrete is composed of an arc that is convex toward the inner space of the tunnel.
The chamfered portion formed on the inner edge of the joint surface of the existing concrete is directed toward the inner space of two tunnels having different curvatures that are smoothly continuous in the direction connecting the inner peripheral surface of the existing concrete and the joint surface. Consists of a convex arc
Of the two arcs having different curvatures, the lining concrete of the tunnel is characterized in that the curvature of the arc adjacent to the joint surface is small. The tunnel lining concrete construction method according to claim 1, wherein the tunnel lining steel formwork is moved in the axial direction of the tunnel, concrete is sequentially spliced to the inner wall surface of the tunnel, and the tunnel lining concrete according to claim 1 is constructed. There,
A flexible groove formwork provided with a concrete casting surface for forming a chamfered portion having a curved surface on the inner edge of the facing surface of the newly constructed concrete on the wellhead side of the dam provided in the tunnel lining steel formwork. As well as installing
A rigid groove formwork for forming a chamfered portion having a curved surface on the inner edge of the end surface parallel to the facing surface of the newly constructed concrete is installed on the end frame provided in the tunnel lining steel formwork.
The tunnel lining steel formwork is installed so that the wellhead side of the flexible groove formwork abuts on the chamfered portion of the existing concrete .
A method for constructing lining concrete, wherein the flexible groove formwork is made of a member that causes elastic deformation, and the rigid groove formwork is made of a steel material . In the method for constructing lining concrete according to claim 2.
A method for constructing lining concrete, characterized in that the height of the flexible groove formwork is formed lower than the height of the rigid groove formwork .

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