JP7360128B2 - How to pull out and remove the joint forming plate member - Google Patents

Description

The present invention relates to a method for pulling out and removing a joint forming plate member, and particularly to a method for pulling out and removing a joint forming plate member for forming an induced joint in tunnel lining concrete. Regarding how to pull out and remove.

For example, in tunnel construction methods such as the mountain tunnel construction method, a method that uses a tunnel lining formwork called a center is used as a method for forming tunnel lining concrete that is constructed to cover the ground on the inner circumferential surface of an excavated tunnel. is generally adopted (for example, see Patent Document 1 and Patent Document 2). For example, as shown in FIG. 10, the tunnel lining formwork 50 is installed along the inner peripheral surface of the tunnel 53, which has a shape including an arch-shaped portion 52 such as a horseshoe shape, and extends from the side wall 55 of the tunnel 53 to the upper part. The lining space 71 between the installed tunnel lining formwork 50 and the ground covered with the shotcrete 54 on the inner peripheral surface of the tunnel 53 is preferably filled with unreinforced concrete. By setting and curing the concrete, tunnel lining concrete is formed so as to be continuous with the concrete of the invert section 51 at the bottom of the tunnel.

Further, as the tunnel lining formwork 50, for example, in addition to an assembly type tunnel lining formwork called a rose center, a movable tunnel lining formwork called a slide center is known. As the excavation work progresses, the tunnel lining formwork 50 is reinstalled every predetermined construction span of about 10.5 m, for example, and the tunnel lining formwork 50 is reinstalled from the rear to the front in the excavation direction of the tunnel 53. The frame 50 is used to form the tunnel 53 by sequentially pouring concrete lining on the sides and top thereof.

In order to cast lining concrete for the sides and upper part of the tunnel using the tunnel lining form 50, for example, as shown in FIGS. 11(a) to 11(d), As a height area in which concrete can be cast through the inspection window 56 provided in the formwork 50, for example, the area from the side wall 55 of the tunnel 53 to the shoulder of the arch-shaped portion 52 is placed through the inspection window 56. At the same time, a vibrator 58 is inserted through the inspection window 56, and the concrete 57 is poured while compacting the supplied concrete 57 (see FIGS. 11(a) to (c)). After that, while supplying concrete 57 through the inspection window 56, a tunnel A pattern is adopted in which concrete 57 is press-fitted and poured in a blow-up method from a blow-up inlet 70 provided at the top of the lining formwork 50 to form the concrete 57 of the crown portion 59 (Fig. 11(d) )reference).

More specifically, after installing the tunnel lining form 50 at a predetermined position, concrete 57 is poured from the lower part of the side wall 55 through the lower inspection window 56 and compacted using a vibrator 58. (See FIG. 11(a)), and a step of compacting using a vibrator 58 while pouring concrete 57 toward the upper arch-shaped portion 52 of the side wall portion 55 through the middle inspection window 56 (see FIG. 11(a)). b)) and further compacting using a vibrator 58 while pouring concrete 57 through the upper inspection window 56 and, if necessary, the blow-up inlet 70, up to just before the crown 59 of the arch-shaped portion 52. (See FIG. 11(c)) and the step of press-fitting concrete 57 from the part of the crown part 59 on the side of the existing lining concrete 72 through the blow-up injection port 70 and filling the concrete up to the gable formwork 73. (See FIG. 11(d)), the lining concrete is placed.

Japanese Patent Application Publication No. 2001-280094 Japanese Patent Application Publication No. 2003-262096 Japanese Patent Application Publication No. 2015-67949

On the other hand, in recent tunnel construction methods, improvements in excavation technology have allowed the progress of the process of forming concrete lining, from pouring concrete to curing and demolding of tunnel lining formwork, to improve the progress of the tunnel face surface. It has become impossible to follow the progress of the excavation process. For this reason, techniques for speeding up the progress of the process of forming lining concrete include using multiple concrete pumps (for example, see Patent Document 3), and using tunnel linings that have a construction length of about 10.5 m, which is commonly used. Instead of construction formwork, long-span tunnel lining formwork with a construction length of approximately 18 m to 22 m is used to extend the construction span of tunnel lining concrete, which is carried out in one cycle, thereby reducing the construction period. It is being considered to shorten the

In addition, when the construction span of tunnel lining concrete performed in one cycle is extended using a long-span tunnel lining formwork that preferably has a construction extension of about 18 m to 22 m, in the middle part of the construction span, Since cracks are likely to occur due to drying shrinkage and temperature shrinkage, especially when forming tunnel lining concrete with a long construction span, it is necessary to induce cracks due to drying shrinkage and temperature shrinkage in the middle part of the tunnel lining concrete. It is desirable to provide joints. For this reason, the applicant of the present application proposes, for example, in Japanese Patent Application No. 2018-147241, as a method of providing an induced joint in the middle part of tunnel lining concrete, a method of protruding into the lining space from the formwork surface of the formwork for tunnel lining. Then, a plurality of joint forming plate members are arranged circumferentially and removably attached, and when the concrete poured in the lining space hardens, the joint forming plate members are installed in the lining. A method of forming induced joints by pulling them out of a space is disclosed.

On the other hand, the work of pulling out the joint forming plate member from the tunnel lining concrete that has been cast in the lining space and hardened is such that the joint forming part of the joint forming plate member is attached to the hardened surrounding tunnel lining concrete. Due to the strong adhesion, a large pulling force is required, especially when cutting the joint forming part of the joint forming plate member and the hardened surrounding tunnel lining concrete for the first time. It is difficult to pull out the joint forming plate member only by manual operation.

For this reason, work has been carried out to pull out the joint forming plate members using various pulling jigs such as Lever Block (registered trademark), but inside the formwork body of the formwork for tunnel lining, It may be difficult to obtain support reaction force when pulling out the joint forming plate member from various equipment or temporary members installed in the space, and depending on the location where the joint forming plate member is installed. , a lot of effort is required to provide a mechanism to stably obtain a supporting reaction force.

The present invention makes it possible to easily obtain support reaction force in a stable state with a simple configuration when pulling out a joint forming plate member inside a tunnel lining formwork, thereby eliminating the need for much effort. It is an object of the present invention to provide a method for pulling out and removing a joint forming plate member, which can efficiently pull out and remove each of a plurality of joint forming plate members installed in series in the circumferential direction. do.

In the mountain tunnel construction method, the present invention is applied to tunnel lining concrete that is removably attached to the axially intermediate portion of the tunnel lining form that is installed when constructing the tunnel lining concrete. A method for pulling out and removing a joint forming plate member for forming a joint after concrete that has been placed has hardened, the method comprising: the tunnel lining formwork; comprises a pedestal section movable in the direction of excavation of the tunnel, and a formwork body supported by the pedestal section to form a lining space between the inner wall surface of the tunnel; is composed of a plurality of split formwork main bodies divided in the tunnel excavation direction, and a slit-like gap is formed around the entire circumference between the adjacent ends of these split formwork main bodies. The plurality of joint forming plate members are each inserted into the slit-like gap, and the inserted joint forming plate members form a joint on the outer peripheral side. The inner protruding grip portion on the inner periphery side is fixed to the split formwork main body portion in a state where the portion protrudes into the lining space, and is attached in a continuous manner in the circumferential direction, and the joint portion The forming plate member is provided with a pull-out engaging portion that engages a pull-out edge cutting means on the inner protruding grip portion, and the pull-out edge cutting means is engaged with the pull-out engaging portion when the split mold By obtaining a support reaction force from the frame main body and displacing it, a force is generated in the direction of pulling out the joint forming plate member inside the divided form main body, and the joint forming plate member is displaced. The joint forming part is cut off from the surrounding hardened concrete that is in close contact with the joint forming part, and then the joint forming plate member is pulled out and removed inside the divided formwork body , The pull-out engagement portion includes an action point protrusion that is fixed and protrudes perpendicularly from the inner protruding grip portion of the joint forming plate member, and the pull-out edge cutting means connects the action point protrusion and the split formwork body. By displacing the rod-shaped member with the tip inserted in the rotational direction, the joint forming plate member is attached to the split formwork body by lever principle. The above object has been achieved by providing a method for pulling out and removing a joint forming plate member that generates a force in the pulling direction inside the joint portion .

Further, in the method for pulling out and removing a joint forming plate member of the present invention, it is preferable that the action point protrusion is removably fixed to the inner protruding grip portion of the joint forming plate member.

Furthermore, in the method for pulling out and removing a joint forming plate member of the present invention, the action point protrusions are arranged in pairs on both sides of the inner protruding grip portion of the joint forming plate member across the circumferential center line. By inserting the tip portions of the two rod-shaped members from the outside between each of the application point protrusions and the split formwork main body and displacing them in the rotational direction, Preferably, based on this principle, a force is generated in a direction to pull out the joint forming plate member toward the inside of the divided form body.

According to the method for pulling out and removing a joint forming plate member of the present invention, the support reaction force when pulling out the joint forming plate member inside the tunnel lining formwork can be easily reduced in a stable state with a simple configuration. Accordingly, each of the plurality of joint forming plate members installed in succession in the circumferential direction can be efficiently pulled out and removed without requiring much effort.

This is a schematic cross-sectional view of a tunnel lining formwork in which a plurality of joint forming plate members are arranged in series in the circumferential direction of the split formwork main body with the joint forming parts protruding into the lining space. . FIG. 2 is a schematic vertical sectional view illustrating a tunnel lining formwork to which a joint forming plate member is attached. It is a schematic plan view explaining the tunnel lining formwork to which the plate member for joint part formation was attached. FIG. 2 is an enlarged sectional view taken along line AA in FIG. 1 at section A' in FIG. 2, illustrating an attachment structure for attaching a joint forming plate member to a tunnel lining form; It is a front view of the plate member for joint part formation. FIG. 6 is a side view (view in the direction of arrow B in FIG. 5) of the joint forming plate member. (a) and (b) are explanatory diagrams of a method for pulling out and removing a joint forming plate member according to a first preferred embodiment of the present invention. (a) and (b) are explanatory diagrams of a method for pulling out and removing a joint forming plate member according to a second preferred embodiment of the present invention. (a) and (c) are explanatory diagrams of the method for pulling out and removing the joint forming plate member according to the third preferred embodiment of the present invention, (b) is an enlarged view of part B in (a), and (d) is It is an enlarged view of part C in (c). FIG. 2 is a schematic cross-sectional view illustrating a state in which a tunnel lining formwork is installed along the inner circumferential surface of a tunnel in a conventional tunnel lining concrete casting method. (a) to (d) are schematic side views, partially shown as cross-sectional views, for explaining the work procedure of a conventional tunnel lining concrete placing method.

A method for pulling out and removing a joint forming plate member according to a first preferred embodiment of the present invention (see FIGS. 7(a) and 7(b)) is performed in a mountain tunnel construction method using tunnel lining concrete 4 that covers the inner wall surface of a tunnel. (See Figures 2 and 3) using tunnel lining formwork 1 (See Figures 1 to 3), joints for forming induced joints in tunnel lining concrete 4 to be constructed. This method is adopted for pulling out and removing the section forming plate member 15 (see FIG. 4) from the tunnel lining concrete 4 after the concrete cast in the lining space S has hardened. In the first embodiment, the tunnel lining concrete 4 constructed to cover the inner peripheral surface of the excavated tunnel T has a length of 10.5 m, which is generally used as a tunnel lining form 1 called a center. Instead of a tunnel lining form 1 having a construction extension of approximately 18 m to 22 m, the joint forming plate member 15 is preferably formed using a long span tunnel lining form 1 having a construction extension of approximately 18 m to 22 m. will be installed in the middle part of the construction span of the tunnel lining concrete 4 to be constructed as a member for forming an inducing joint that induces cracks due to drying shrinkage and temperature shrinkage.

In other words, in the recent mountain tunnel construction method, improvements in excavation technology have allowed the progress of the process for forming the lining concrete 4, from concrete placement to curing and demolding of the tunnel lining form 1, to improve the tunnel lining. In many cases, it is not possible to keep up with the progress of the process of excavating the T face face, and the construction is not carried out efficiently. Instead of the lining formwork, a long span tunnel lining form 1 having a construction extension of preferably 10.5 m or more is used, for example, a long span tunnel lining form having an extension of about 18 to 22 m. 1 increases the construction span of concrete lining 4 in one cycle, and simultaneously places concrete 12 from two systems of pressure-feeding piping 31 using two concrete pumps 30. By shortening the working time when pouring concrete 12, the progress of the process for forming concrete lining 4 can be accelerated.

In addition, in the first embodiment, by using the long-span tunnel lining formwork 1, if the extension of the construction span of one cycle of the lining concrete 4 is increased, it is possible to increase the length of the construction span in one cycle of the lining concrete 4. , cracks caused by drying shrinkage and temperature shrinkage of concrete cannot be sufficiently absorbed, and cracks are likely to occur in the middle part of the construction span. Therefore, a joint forming plate member 15 is inserted into the slit-shaped gap δ to form a joint that induces cracks due to drying shrinkage and temperature shrinkage in the middle part of the construction span (see Fig. 4). , a pair of split formwork bodies that are arranged in succession in the circumferential direction with the joint forming part 15A protruding into the lining space S, and that constitute the formwork main body part 3 of the formwork 1 for tunnel lining. It is fixedly attached to the ends of parts 3A and 3B. In the method of pulling out and removing the joint forming plate member of the first embodiment (see FIGS. 7(a) and (b)), after the concrete poured in the lining space S has hardened, the joint is removed from the hardened concrete. When the part forming plate member 15 is pulled out to form the induced joint, the supporting reaction force can be easily obtained in a stable state, and the plate member 15 for forming the part can be installed in succession in the circumferential direction without requiring much effort. This method was adopted as a method for efficiently pulling out and removing each of the plurality of joint forming plate members 15.

The method for pulling out and removing the joint forming plate member of the first embodiment is based on the tunnel lining formwork ( A joint forming plate member 15 (see FIGS. 1 to 3) for forming an induced joint in the tunnel lining concrete 4 to be constructed is removably attached to the middle part in the axial direction This is a pull-out method for removing concrete (see Fig. 6) after the poured concrete has hardened (see Figs. 7(a) and (b)).

As shown in FIGS. 1 to 3, the tunnel lining formwork 1 is placed between a pedestal part 2 movable in the tunnel excavation direction X and an inner wall surface of the tunnel T supported by this pedestal part 2. It includes a formwork main body part 3 that forms a lining space S. The formwork main body part 3 is composed of a plurality of (in the present first embodiment, a pair) split formwork main body parts 3A and 3B that are divided (in the present first embodiment, into two) in the tunnel excavation direction. A slit-shaped gap δ (see FIG. 4) is formed continuously over the entire circumference between the adjacent ends of these split formwork main bodies 3A and 3B. A plurality of joint forming plate members 15 are each inserted into this slit-shaped gap δ (see FIG. 1), and the inserted joint forming plate members 15 are connected to the joint forming portion 15A on the outer peripheral side. (See Fig. 5) is projected into the lining space S, and the inner protruding grip portion 15B on the inner periphery side is preferably fixed to the split formwork body portions 3A and 3B on both sides with a slit-shaped gap δ in between. (see FIG. 4), and are attached in a continuous manner in the circumferential direction.

In the method for pulling out and removing the joint forming plate member of the first embodiment, as shown in FIGS. 7(a) and (b)), and the pull-out edge cutting means 20 is provided with a pull-out engaging portion 15a that engages the pull-out engaging portion 15a, as shown in FIGS. 7(a) and (b). In the engaged state, the joint forming plate member 15 is moved inside the split formwork main bodies 3A, 3B by obtaining a supporting reaction force from the split formwork main bodies 3A, 3B and displacing it, for example, in the rotational direction R. A force in the pulling direction Z is generated to cut the joint forming portion 15A of the joint forming plate member 15 from the surrounding hardened concrete that is in close contact with the joint forming portion 15A, and then, the joint forming plate member 15 is It is designed to be removed by pulling it out inside the divided formwork body parts 3A and 3B.

In addition, in the method for pulling out and removing a joint forming plate member according to the first embodiment, the pulling engaging portion 15a is a fixed working point that projects perpendicularly from the inner protruding grip portion 15B of the joint forming plate member 15. The drawing edge cutting means 20 consists of a rod-shaped member 61 with a tip end portion 61a inserted between the action point projection 60 and the divided formwork main bodies 3A and 3B (see FIG. 7(a)). By displacing the rod-like member 61 into which the joint portion 61a is inserted, preferably in the rotational direction R around the concave support portion 62a at the tip of the upright fulcrum plate 62, the joint forming plate member 15 is moved by the lever principle. A force in the pulling direction Z is generated inside the divided formwork main bodies 3A, 3B.

Furthermore, in the method for pulling out and removing the joint forming plate member of the first embodiment, the action point protrusion 60 is located at the circumferential center line C (see FIG. 5) of the inner protruding grip portion 15B of the joint forming plate member 15. The tip portions 61a of the two rod-shaped members 61 are inserted from the outside between each of the application point protrusions 60 and the divided formwork main body portions 3A, 3B. By inserting and displacing each in the rotational direction R (see FIG. 7(a)) preferably around the concave support portion 62a (see FIG. 4) at the tip of the upright fulcrum plate 62, by the lever principle, A force is generated in the direction Z that pulls out the joint forming plate member 15 to the inside of the divided formwork body parts 3A, 3B.

In the first embodiment, the tunnel lining formwork 1 to which a plurality of joint forming plate members 15 are attached to the intermediate portion is a sliding center movable in the extension direction (excavation direction) X of the tunnel T. For example, it is a long span center with an extension of about 18 to 22 meters. The tunnel lining formwork 1 has substantially the same configuration as the tunnel lining formwork described in, for example, Japanese Unexamined Patent Publication No. 2015-67949, except that it is a long span center.

That is, as shown in FIGS. 1 to 3, the tunnel lining formwork 1 includes a frame portion 2 formed by a plurality of gate-shaped carts 2A, which are connected and integrated in the excavation direction X of the tunnel T (see FIG. 2). , are supported by the pedestal section 2 formed by these integrated gate-shaped carts 2A, and are arranged along the inner peripheral surface of the tunnel T covered with a primary lining 5 made of, for example, shotcrete (see FIG. 1). ), and a formwork main body part 3 that forms the inner formwork surface of the lining space S. The gate-shaped trolley 2A that constitutes the pedestal section 2 includes a base section 2a and support leg sections 2b that support the base section 2a. A running section 7 that can run along a rail 6 laid on the floor surface of the tunnel T is provided at the lower end of the support leg section 2b. It is designed to be able to move in the excavation direction X.

The formwork main body 3 is assembled so as to have a shape that follows the inner circumferential surface of the tunnel T covered by the primary lining 5, and is spaced at a predetermined distance from the inner circumferential surface of the tunnel T. By arranging them, a lined space S with a predetermined thickness is formed, which is a space for placing concrete. Further, as shown in FIG. 1, the formwork main body 3 includes an upper formwork 3a for forming a lining space S above the arch-shaped portion 52 of the tunnel T, and an upper formwork 3a for forming a lining space S above the arch-shaped portion 52, and a lower portion and both sides of the arch-shaped portion 52. A pair of side forms 3b for forming a lined space S in the upper part of the side wall part 55, and a pair of lower end parts for forming a lined space S in the lower part of the side wall part 55 connected to the concrete of the invert part. It is configured to include a formwork 3c. The upper formwork 3a is supported by a plurality of elevating jacks 8 provided on the base portion 2a of the gate-shaped trolley 2A constituting the gantry portion 2 so as to be vertically movable. The pair of side formworks 3b are rotatably connected to the lower ends of the upper formwork 3a on both sides via rotary connecting parts 3d, and the pair of lower end formworks 3c are connected to the lower end portions of the upper formwork 3a on both sides. It is rotatably connected to the lower end of 3b via a lower rotational connection part 3e. One end of the side formwork 3b and the lower end formwork 3c are connected to the other ends of telescopic jacks 9a, 9b connected to the gate-shaped trolley 2A, and these telescopic jacks 9a, 9b cannot be expanded or contracted. The side formwork 3b and the lower end formwork 3c can be rotated with respect to the upper formwork 3a and the side formwork 3b.

As a result, the formwork 1 for tunnel lining can be expanded and contracted by the lifting jack 8 and the telescopic jacks 9a and 9b, so that the formwork main body 3 can be expanded or gathered inside. The formwork main body 3 can be assembled along the inner circumferential surface of the tunnel T, or the formwork main body 3 can be moved in the excavation direction X inside the tunnel T after being demolded.

Further, in the first embodiment, the upper formwork 3a and the side formwork 3b of the formwork main body 3 are provided with a plurality of press-fit connection ports 11a and 11b, respectively, at intervals in the excavation direction X of the tunnel T. It is formed in two places (see Figure 2). At the top end of the upper formwork 3a of the formwork body 3, a plurality of zenith press-fit connection ports 27 are formed at two locations spaced apart in the excavation direction X of the tunnel T. These press-fit connection ports 11a, 11b, and 27 are used for the purpose of pouring or press-fitting concrete 12 for lining, which is pumped through the pressure-feeding pipe 31, into the lining space S, as will be described later. used.

In the first embodiment, the formwork main body 3 of the tunnel lining formwork 1 preferably has two It is composed of a pair of divided formwork body parts 3A and 3B. The pair of split formwork main bodies 3A and 3B are arranged and fixed such that a slit-shaped gap δ (see FIG. 4) of a constant width is formed between the adjacent end surfaces over the entire circumference. has been done. In addition, the formed slit-shaped gap δ is supported by end rib plates 21A and 21B that form the end faces of the pair of split formwork main bodies 3A and 3B, and the middle part of each construction span (L = 18 m) is A plurality of joint forming plate members 15 for forming induced joints in the joint are inserted and arranged in a removable manner with the joint forming part 15A protruding into the lining space S, over the entire circumference. They are arranged in series (see Figure 1).

In the first embodiment, in the inner protruding grip portion 15B, which is the portion on the inner peripheral side of the joint forming plate member 15, there are at least two locations (in the first embodiment) in a portion adjacent to the joint forming portion 15A. Plate-side pin insertion holes 16a are formed at two locations in this embodiment (see FIG. 5). The end rib plates 21A, 21B forming the end faces of the pair of split formwork main bodies 3A, 3B have a joint forming portion 15A, which is a portion on the outer periphery side of the joint forming plate member 15, in the lining space. End surface pin insertion holes 23a are formed at positions that match these plate-side pin insertion holes 16a in the state of protruding in the direction S (see FIG. 4). By inserting the pin member 26 (see FIG. 4) into the matched plate side pin insertion hole 16a and end face pin insertion hole 23a, the joint forming plate member 15 is inserted into the end rib plates 21A and 21B on both sides. It is fixed and attached in a sandwiched and supported state.

Further, in the first embodiment, as shown in FIG. 4, the outer circumferential surface of each end edge of the pair of split formwork main bodies 3A, 3B, preferably located on both sides of the slit-shaped gap δ. The face wood members 22A, 22B, which are erected from the top and preferably have a right triangular or right trapezoidal cross-sectional shape, protrude into the lining space S, preferably from the respective split formwork main bodies 3A, 3B. It is attached continuously over the entire circumference in the circumferential direction.

In the first embodiment, the joint forming plate member 15 is preferably made of aluminum or steel and has a thickness of about 6 to 10 mm (in this embodiment, about 7 mm), as shown in FIGS. 5 and 6. It is formed using a metal plate with a thickness of Further, the joint forming plate member 15 has an outer circumferential side portion having a vertical width of about 300 to 600 mm and a horizontal width of about 400 to 700 mm, and an inner circumference disposed opposite to the outer circumferential side portion. It has a substantially four-sided planar shape having a side portion and side portions on both left and right sides. The joint forming plate member 15 has a portion on the outer peripheral side serving as a joint forming portion 15A that is arranged to protrude from the formwork surface into the lining space S, and a portion on the inner peripheral side side. is an inwardly protruding grip portion 15B that is arranged to protrude inside the form body 3.

As shown in FIG. 4, the joint forming portion 15A is provided extending in the circumferential direction between the end rib plates 21A and 21B that form the end surfaces of the pair of split formwork main bodies 3A and 3B. In addition, when the joint forming plate member 15 is inserted into the lining space S through the slit-shaped gap δ, from the formwork surface by the outer periphery of the pair of split formwork main bodies 3A and 3B. , for example, so as to protrude outward with a protrusion height of about 200 mm. Further, it is preferable that the joint forming portion 15A is tapered so that the thickness is reduced from about 7 mm to about 2 mm toward the tip.

The inner protruding gripping part 15B functions as a temporary fixing part for fixing the joint forming plate member 15 until the concrete poured in the lining space S hardens, and also functions as a temporary fixing part for fixing the joint forming plate member 15 until the concrete poured in the lining space S hardens. This is a portion that functions as a handle when pulling out the plate member 15 inside the form body 3. As shown in FIGS. 5 and 6, the inner protruding gripping portion 15B has a pair of plate sides arranged symmetrically on both sides of the center line C in the width direction at a portion adjacent to the joint forming portion 15A. A pin insertion hole 16a is formed. As described above, the pair of plate-side pin insertion holes 16a are inserted into the end surfaces of the split formwork main bodies 3A and 3B with the joint forming portion 15A of the joint forming plate member 15 protruding into the lining space S. The pins are formed at positions that match each of the pair of end face pin insertion holes 23a formed in the end rib plates 21A and 21B (see FIG. 4). As a result, as described above, by inserting the pin member 26 (see FIG. 4) into the matched plate side pin insertion hole 16a and end face pin insertion hole 23a, the joint forming plate member 15 can be inserted into the divided formwork. It is attached to the end rib plates 21A, 21B of the main body parts 3A, 3B in a supported state.

Further, in the first embodiment, a pair of action point protrusions 60 are arranged symmetrically on both sides of the center line C in the width direction in a portion of the inner protruding grip portion 15B adjacent to the inner peripheral side portion. is provided as a pull-out engagement portion 15a. The action point protrusion 60, which is the pull-out engagement portion 15a, is a cylindrical portion made of steel and has a diameter of, for example, about 20 mm. It protrudes perpendicularly to the surface, for example, at a height of about 50 mm, and is fixedly attached as one piece by, for example, welding or the like. The action point protrusion 60 is removably fixed to the inner protruding grip part 15B by fitting or screwing into a fixing hole formed in the inner protruding grip part 15B of the joint forming plate member 15, for example. You can also do that. At each point of application protrusion 60, a tip portion 61a of a rod-shaped member 61 made of a steel rod, which is the drawing edge cutting means 20, is attached to a base plate 25 (FIGS. 4 and 7) fixed to one of the divided formwork body parts 3A. (a) and (b)) are inserted into the gap between the two.

Furthermore, in the first embodiment, a pair of action point protrusions 60 are arranged symmetrically on both sides of the center line C in the width direction in a portion of the inner protruding grip portion 15B adjacent to the inner peripheral side portion. On the outside of the lining space S, after the concrete poured in the lining space S has hardened, there is a horizontally long rectangular shape that functions as a handle when pulling out the joint forming plate member 15 to the inside of the divided formwork body parts 3A and 3B. A pair of openings 19 for the handle are formed.

On the other hand, in the first embodiment, for example, the action point is A substrate plate 25 is fixed to the divided formwork main body 3A on one side of the joint forming plate member 15 from which the protrusion 60 projects, supported by the end rib plate 21A and the reinforcing rib plate 24A. (See FIGS. 4, 7(a) and 7(b)). A strip-shaped fulcrum plate 62 is erected from the substrate plate 25 inside the split formwork main body 3A by, for example, welding or the like. It is fixed and attached as one piece. A concave support portion 62a that curves concavely is formed at the tip of the upright fulcrum plate 62 (see FIG. 4).

In the first embodiment, the side peripheral surface of the tip portion 61a of the rod-shaped member 61 made of a steel rod is brought into contact with the concave support portion 62a at the tip of the upright fulcrum plate 62, and the rod-shaped member The tip of the tip portion 61a of 61 is inserted between the action point protrusion 60 of the joint forming plate member 15 inserted into the slit-shaped gap δ and the substrate plate 25 fixed to the split formwork main body 3A. From the state in which it has been inserted by force (see FIG. 7(a)), the rod-shaped member 61 is rotated in the rotational direction indicated by R in the figure, using the concave support portion 62a of the upright fulcrum plate 62 as a fulcrum. It can be displaced. As a result, the joint forming plate member 15 is moved into the divided formwork by using the tip of the tip portion 61a of the rod-shaped member 61, which is forced between the point of action projection 60 and the substrate plate 25, as the point of action. Since it is possible to generate a force in the pulling direction Z inside the main body portion 3A, by slightly pulling out the joint forming plate member 15, the joint forming portion 15A of the joint forming plate member 15, It becomes possible to cut off the adhesion to the hardened surrounding tunnel lining concrete.

In addition, in the first embodiment, the joint forming portion 15A is made to protrude into the lining space S from the formwork surface formed by the outer circumferential surface of the split formwork main bodies 3A, 3B, and the periphery of the split formwork main bodies 3A, 3B is As shown in FIG. 1, the plurality of joint forming plate members 15 arranged in series in the direction are preferably arranged at the boundary between the side edges of each pair of adjacent plate members 15. The connecting portion 15C is arranged so that no gap is formed. Further, in some of the plurality of joint forming plate members 15 arranged in series, the interval between the side edges on both sides is oriented from the outer circumferential side to the inner circumferential side of the lining space S. It is a plate member including a V-shaped plate portion having a front face shape that widens inwardly and widens toward the inside (see FIG. 5).

Some of the plurality of joint forming plate members 15 arranged in series in the circumferential direction have a shape in which the interval between the side edges on both sides widens toward the inner circumferential side of the lining space S. Since the plate member 15' includes the letter-shaped plate portion, by pulling out the plate member 15' including the letter-shaped plate portion in advance, the plate member 15' includes the letter-shaped plate portion. The plate members 15 arranged in series are arranged so that each plate member 15 can be pulled out smoothly without making it difficult to pull out due to the side edges of adjacent plate members 15 competing with each other at the split connection part 15C. It becomes possible to

As described above, the joint forming portions 15A of the plurality of joint forming plate members 15 are inserted into the slit-shaped gaps δ between the end rib plates 21A and 21B of the pair of split formwork main bodies 3A and 3B. By inserting each joint part forming plate member 15 in a continuous arrangement in the circumferential direction and attaching it, the inner circumferential surface of the tunnel T covered by the primary lining 5 and the mold of the tunnel lining formwork 1 are attached. Work is carried out to construct tunnel lining concrete 4 by pouring concrete into a lining space S, which is a concrete pouring space, formed between the outer peripheral portion of the frame body 3 and the formwork surface. It will be done. In the first embodiment, as shown in FIGS. 2 and 3, the work of constructing the tunnel lining concrete 4 involves pumping concrete from two concrete pumps 30 through pressure feeding pipes 31 extending respectively. This can be carried out by simultaneously supplying and pouring into the lining space S.

In this embodiment, the two concrete pumps 30 are placed at the front and rear of the tunnel T in the excavation direction X, sandwiching the tunnel lining formwork 1 carried into the tunnel T. Concrete 12 is charged into the hopper portion of the concrete pump 30 from each concrete mixer truck 32, respectively. Here, pressure-feeding pipes 31 extend from the two front and rear concrete pumps 30, and the concrete 12 charged from each concrete mixer truck 32 to the hopper section of each concrete pump 30 is transferred to each of the two systems for pressure-feeding. They are simultaneously pressure-fed and supplied from the piping 31 to the lining space S. In this way, by using two systems of concrete pumps 30 and pressure-feeding piping 31, the progress of the process for forming tunnel lining concrete 4 can be effectively accelerated.

Two systems of pressure-feeding pipes 31 extending from the two concrete pumps 30 include a main pipe 31a extending toward the inside of the tunnel lining form 1, and a main pipe 31a extending in the width direction of the tunnel T via a rotary valve 29 from the main pipe 31a. It is configured to include left and right branch pipes 31b branched on both sides. Here, each branch pipe 31b is configured to include a plurality of piece pipes such as straight pipes and curved pipes having different lengths, and the selected plurality of piece pipes are assembled to form the press-fit connection ports 11a, 11b. are arranged so as to be connected to each other. Moreover, by rearranging these piece pipes, the branch pipe 31b is formed preferably at the rear end of each of the two divided formwork main bodies 3A and 3B in the excavation direction X. In addition, the concrete 12 is poured by switching from the lower press-fit connection port 11a to the upper press-fit connection port 11b, or by switching from the upper press-fit connection port 11b to the top press-fit connection port 27. It is now possible to do so.

In the first embodiment, once the concrete poured in the lining space S has hardened and the tunnel lining concrete 4 has been formed, the above-mentioned According to the method of pulling out and removing joint forming plate members, each of the plurality of joint forming plate members 15 is pulled out from the lining space S to the inside of the formwork main body 3 to form an induced joint. It turns out. That is, according to the method for pulling out and removing joint forming plate members of the first embodiment, when each of the joint forming plate members 15 is pulled out from the lining space S to the inside of the formwork main body 3. As described above, the side peripheral surface of the tip portion 61a of the rod-shaped member 61 is brought into contact with the concave support portion 62a at the tip of the upright fulcrum plate 62, and the tip portion of the rod-shaped member 61 is The tip of 61a is forced between the action point protrusion 60 of the joint forming plate member 15 inserted into the slit-like gap δ and the substrate plate 25 fixed to the split formwork main body 3A. (See FIG. 7(a)). Thereafter, the rod-shaped member 61 is rotated and displaced in the rotational direction indicated by R in the figure, using the concave support portion 62a of the upright fulcrum plate 62 as a fulcrum. As a result, the joint forming plate member 15 is moved into the divided formwork by using the tip of the tip portion 61a of the rod-shaped member 61, which is forced between the point of action projection 60 and the substrate plate 25, as the point of action. Since it becomes possible to generate a force in the direction Z to pull out the main body portion 3A, the joint forming plate member 15 moves slightly in the Z direction, thereby forming the joint of the joint forming plate member 15. It becomes possible to remove the adhesion between the portion 15A and the hardened surrounding tunnel lining concrete by cutting the edges, and thereby, the joint forming plate member 15 that has been cut off from the surrounding hardened concrete. can be smoothly pulled out to the inside of the divided formwork body parts 3A, 3B and removed.

Therefore, according to the method for pulling out and removing the joint forming plate member of the first embodiment, the support reaction force when pulling out the joint forming plate member inside the tunnel lining formwork is reduced by the lever principle. By obtaining directly from the split formwork main body 3A via the upright fulcrum plate 62 and the substrate plate 25 that serve as fulcrums, it is possible to easily obtain it in a stable state with a simple configuration, which requires a lot of effort. It becomes possible to efficiently pull out and remove each of the plurality of joint-forming plate members installed in series in the circumferential direction without any trouble.

In addition, in the method for pulling out and removing the joint forming plate member of the first embodiment, the fulcrum is erected from the substrate plate 25 fixed to the split formwork main body 3A, and is provided with a concave support portion 62a at the tip. It is not necessary that the plate 62 be attached. For example, from a state in which the tip of the tip portion 61a is inserted between the action point protrusion 60 of the joint forming plate member 15 and the substrate plate 25 fixed to the split formwork main body 3A, The rod-like member 61 can also be rotated and displaced in a direction R' opposite to the rotational direction indicated by R in FIG. As a result, the joint forming plate member 15 is moved inside the split formwork main body 3A by the principle of leverage using the side surface of the tip of the tip portion 61a of the rod-like member 61 that comes into contact with the point of action projection 60 as the point of action. By generating a pulling force in the Z direction and slightly moving the joint forming plate member 15 in the Z direction, the joint forming part 15A of the joint forming plate member 15 and the hardened surrounding tunnel lining concrete are removed. It may be possible to remove the stuck state by cutting the edges.

FIGS. 8A and 8B are explanatory views of a method for pulling out and removing a joint forming plate member according to a second preferred embodiment of the present invention. In the pull-out and removal method of the second embodiment shown in FIGS. 8(a) and 8(b), the pull-out engaging portions 15a are fixed so as to protrude from both sides of the inwardly protruding grip portions 15B of the joint forming plate member 15. , a pair of reaction force plates 63 having female screw holes 63a, and the drawing edge cutting means 20 is screwed into each female screw hole 63a of the pair of reaction force plates 63, and by rotating, for example, the split formwork main body. It consists of a pair of bolt members 64 that move forward and backward toward the substrate plate 25' fixed to the parts 3A and 3B. By rotating these bolt members 64 and displacing the tip portions so as to press the substrate plate 25' fixed to the divided formwork body parts 3A and 3B, the joint forming plate member 15 is attached to the divided formwork. A force in the pulling direction Z is generated inside the main body parts 3A, 3B.

The method for pulling out and removing the joint forming plate member according to the second embodiment also generates a force in the direction Z that pulls out the joint forming plate member 15 inside the divided formwork body parts 3A and 3B, thereby removing the joint. By slightly moving the joint forming plate member 15 in the Z direction, the state where the joint forming part 15A of the joint forming plate member 15 and the hardened surrounding tunnel lining concrete are attached can be cut off. Since it can be released, the same effects as in the first embodiment described above can be achieved.

FIGS. 9(a) to 9(d) are explanatory diagrams of a method for pulling out and removing a joint forming plate member according to a third preferred embodiment of the present invention. In the pull-out and removal method of the third embodiment shown in FIGS. 9(a) to 9(d), the pull-out engagement portion 15a is a plate-side wedge engagement formed on the inwardly protruding grip portion 15B of the joint forming plate member 15. The pull-out edge cutting means 20 is fixed to the divided form body parts 3A and 3B in a state along the inner protruding grip part 15B of the joint forming plate member 15, and is formed of a matching hole 65. It consists of a reaction plate 66 having a force-side wedge engagement hole 66a, and a wedge member 67 driven into the overlapping plate-side wedge engagement hole 65 and reaction-side wedge engagement hole 66a. As shown in FIGS. 9(a) and 9(b), the reaction force side wedge engagement hole 66a is shifted inward in the radial direction of the split formwork body parts 3A and 3B with respect to the plate side wedge engagement hole 65. By driving the wedge member 67 (see FIG. 9(b)), the joint forming plate member 15 is displaced relative to the reaction plate 66 (see FIG. 9(d)), and the joint is formed. A force is generated in the direction Z to pull out the plate member 15 inside the divided formwork body parts 3A, 3B.

Also according to the method for pulling out and removing the joint forming plate member 15 according to the third embodiment, a force in the direction Z that pulls out the joint forming plate member 15 to the inside of the divided formwork body parts 3A and 3B is generated, and the joint forming plate member 15 is pulled out and removed. By slightly moving the joint forming plate member 15 in the Z direction, the state where the joint forming part 15A of the joint forming plate member 15 and the hardened surrounding tunnel lining concrete are attached can be cut off. Since it can be released, the same effects as in the first embodiment described above can be achieved.

Note that the present invention is not limited to the above embodiments, and can be modified in various ways. For example, the formwork main body of the formwork for tunnel lining does not necessarily have to be divided into two parts, but may be divided into three or more parts, and the formwork main body part divided into three or more parts is not necessarily divided into two parts. The method for pulling out and removing a joint forming plate member of the present invention can also be used when pulling out and removing a joint forming plate member inserted into a slit-like gap between adjacent ends after concrete has hardened. can be adopted.

1 Formwork for tunnel lining 2 Frame part 3 Formwork body parts 3A, 3B Divided formwork body part 4 Tunnel lining concrete (lining concrete)
15 Joint forming plate member 15A Joint forming part 15B Inner protruding grip part 15a Pulling engagement part 16a Plate side pin insertion hole 20 Pulling edge cutting means 21A, 21B End rib plate 23a End face pin insertion hole 25, 25' Substrate plate 26 Pin member 60 Point of action protrusion 61 Rod-shaped member 61a Tip portion 62 Erected fulcrum plate 62a Concave support portion 63 Reaction force plate 63a Female screw hole 64 Bolt member 65 Plate side wedge engagement hole 66 Reaction force plate 66a Reaction side wedge engagement Matching hole 67 Wedge member δ Slit-shaped gap S Lining space T Tunnel X Tunnel excavation direction (axial direction of tunnel lining formwork)
Z Direction to pull out the joint forming plate member

Claims (3)

In the mountain tunnel construction method, a trigger joint is formed in the tunnel lining concrete to be constructed, which is removably attached to the axially intermediate part of the tunnel lining formwork that is installed when constructing the tunnel lining concrete. A method for pulling out and removing a joint forming plate member for removing the joint forming plate member after concrete that has been placed has hardened, the method comprising:
The tunnel lining formwork includes a pedestal part that is movable in the tunnel excavation direction, and a formwork main body that is supported by the pedestal part and forms a lining space between it and the inner wall surface of the tunnel. Ori,
The formwork body is composed of a plurality of divided formwork body parts divided in the tunnel excavation direction, and a slit-like gap is formed between adjacent ends of these divided formwork body parts. The plurality of joint forming plate members are each inserted into the slit-like gap, and the inserted joint forming plate members are formed continuously over the entire circumference. With the side joint forming part protruding into the lining space, the inner protruding grip part on the inner periphery side is fixed to the split formwork main body part, and the molded formwork is installed in a continuous manner in the circumferential direction. Ori,
The joint forming plate member is provided with a pull-out engaging portion that engages a pull-out edge cutting means on the inner protruding grip portion, and the pull-out edge cutting means is in a state engaged with the pull-out engaging portion, By obtaining a support reaction force from the split formwork main body and displacing it, a force is generated in the direction of pulling out the joint forming plate member inside the split formwork main body, and the joint forming plate is displaced. The joint forming portion of the member is edged with surrounding hardened concrete that is in close contact with the joint forming portion,
After that, the joint forming plate member is pulled out to the inside of the divided formwork main body and removed,
The pull-out engagement portion includes an action point protrusion that is fixed and protrudes perpendicularly from the inner protruding grip portion of the joint forming plate member, and the pull-out edge cutting means connects the action point protrusion and the split formwork body. By displacing the rod-shaped member with the tip inserted in the rotational direction, the joint forming plate member is attached to the split formwork body by lever principle. A method for pulling out and removing a joint forming plate member that generates a force in the direction of pulling out the joint part . 2. The method for pulling out and removing a joint forming plate member according to claim 1 , wherein the action point protrusion is removably fixed to the inner protruding grip portion of the joint forming plate member. A pair of the action point protrusions are arranged and fixed on both sides of the inner protruding grip part of the joint forming plate member across the circumferential center line, and are fixed to the tip portions of the two rod-shaped members. , by inserting from the outside between each of the application point protrusions and the split formwork main body and displacing it in the rotational direction, the joint forming plate member is inserted into the split formwork main body by the lever principle. 3. The method for pulling out and removing a joint forming plate member according to claim 1 or 2, wherein a force in a pulling direction is generated inside the portion.