JP7449540B2 - How to install plate members for joint formation - Google Patents

Description

The present invention relates to a method for installing a joint forming plate member, and particularly to a method for installing a joint forming plate member for forming induced joints in tunnel lining concrete in a state where it can be pulled out after the concrete has hardened. The present invention relates to a method for installing a plate member for forming joint portions.

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. 9, the tunnel lining formwork 50 is installed along the inner peripheral surface of the tunnel 53, which has a shape that includes an arch-shaped portion 52 such as a horseshoe shape, and extends from the side wall portion 55 of the tunnel 53 to the upper portion. The lining space 61 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 formwork 50 for tunnel lining, for example, in addition to an assembled formwork for tunnel lining called a rose center, a movable formwork for tunnel lining called a slide center is known. As the 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. 50 will be used to sequentially cast and form the lining concrete for the side and upper portions of the tunnel 53.

In order to use the tunnel lining formwork 50 to cast lining concrete for the sides and top of the tunnel, for example, as shown in FIGS. 10(a) to 10(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. 10(a) to 10(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 60 provided at the top of the lining formwork 50 to form the concrete 57 of the crown portion 59 (Fig. 10(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. 10(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 55 through the middle inspection window 56 (see FIG. 10(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 60, up to just before the crown portion 59 of the arch-shaped portion 52. (See FIG. 10(c)) and the process of press-fitting concrete 57 from the part of the crown part 59 on the side of the existing lining concrete 62 through the blow-up injection port 60 and filling the concrete up to the gable form 50a. (See FIG. 10(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 process of forming concrete lining include using multiple concrete pumps (for example, see Patent Document 3), 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 proposed a method for providing an induced joint in the middle part of tunnel lining concrete, for example in JP-A-2020-20246, in which the lining space is formed from the formwork surface of the tunnel lining formwork. The joint forming part is made to protrude, and a plurality of joint forming plate members are arranged consecutively in the circumferential direction and attached so that they can be pulled out. When the concrete poured in the lining space hardens, the joint forming part is A method of forming an induced joint by pulling out a forming plate member from a lining space is disclosed.

Here, when the joint forming portion is made to protrude from the formwork surface of the tunnel lining formwork into the lining space, and a plurality of joint forming plate members are arranged in succession in the circumferential direction and are removably attached. In addition, each of these joint forming plate members allows the joint forming part to stand vertically and accurately in the lining space from the formwork surface of the tunnel lining formwork, and also to erect the joint forming part vertically and precisely from the formwork surface of the tunnel lining formwork, and to It is desirable to install so that the joint forming part continues accurately in the circumferential direction between the parts, and if these joint forming plates are not installed accurately, the concrete placed in the lining space will be damaged. When removing the joint forming plate member after it has hardened, it becomes difficult to pull out the joint forming plate member from the lining concrete.

In particular, the distance between the side edges on both sides in the circumferential direction, which are to be removed first among the joint forming plate members arranged in series in the circumferential direction, is from the outer circumferential side to the inner circumferential side. If the joint forming plate member including the V-shaped portion that expands toward the side and the joint forming plate member adjacent thereto are not installed in an accurate upright manner, the joint forming portion may By shifting in the front-back direction and discontinuing in the circumferential direction, after the joint forming plate member that is a V-shaped plate member is pulled out first, when pulling out the adjacent joint forming plate member. , the side edges of the displaced portions become caught in the hardened concrete, making it difficult to pull out the adjacent joint forming plate member.

In the present invention, each joint forming plate member is vertically installed in the lining space from the formwork surface of the tunnel lining formwork, and is connected to the adjacent joint forming plate member. It is an object of the present invention to provide a method for installing a joint forming plate member that can be installed by accurately adjusting the standing angle so that the joint forming part continues in the circumferential direction between the two.

In the mountain tunnel construction method, the present invention provides an induction joint in the tunnel lining concrete to be constructed, which is removably attached to the axially intermediate portion of the tunnel lining formwork installed when constructing the tunnel lining concrete. A method for installing a joint forming plate member for installing a joint forming plate member forming a joint forming plate member in a state where it can be pulled out after poured concrete has hardened, the tunnel lining formwork comprising: , comprising a pedestal section movable in the tunnel excavation direction, and a formwork body supported by the pedestal section to form a lining space between the inner wall surface of the tunnel, and the formwork main body is It is composed of a plurality of split formwork main bodies divided in the direction of tunnel excavation, and a slit-shaped gap is continuous along the entire circumference between the adjacent ends of these split formwork main bodies. The plurality of joint forming plate members are respectively inserted into the slit-like gaps, and the inserted joint forming plate members are formed in the joint forming portion on the outer peripheral side. The inward protruding grip portions on the inner peripheral side are fixed to the split formwork main body in a state in which they protrude into the lining space, so that they can be installed in a continuous manner in the circumferential direction. In the joint forming plate member, a pair of reaction plates each having a female threaded hole protruding from both the front and back surfaces are fixed to the inner protruding grip portion at least at two positions spaced apart in the circumferential direction. The bolt members are screwed into the female threaded holes of the reaction plate in at least four places, and the bolt members are rotated with their tips in contact with the split formwork main body. By moving the joint forming plate member forward and backward while adjusting the standing angle, the joint forming plate member is installed so that the joint forming portion is continuous in the circumferential direction between adjacent joint forming plate members. The above object has been achieved by providing a method for installing a joint forming plate member.

Further, in the method for installing a joint forming plate member of the present invention, the joint forming plate member installed by adjusting the standing angle is installed on the side portions located on both sides in the circumferential direction of the split formwork main body. A joint forming plate member including a V-shaped part in which the interval between sides increases from the outer peripheral side to the inner peripheral side, and the joint forming part are continuous and adjacent in the circumferential direction. It is preferable that the joint forming plate member is arranged as a joint forming plate member.

According to the method for installing a joint forming plate member of the present invention, each joint forming plate member is vertically installed in the lining space from the formwork surface of the tunnel lining formwork. At the same time, the standing angle can be precisely adjusted and installed so that the joint forming portion is continuous in the circumferential direction between adjacent joint forming plate members.

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; FIG. 2 is a front view of a joint forming plate member including a V-shaped portion. FIG. 6 is a side view (view of FIG. 5 from the left side) of the joint forming plate member. It is an explanatory view of a joint part forming plate member which is arranged adjacent to a joint part forming plate member including a V-shaped portion. It is an explanatory view of the installation method of the plate member for joint part formation concerning one preferred embodiment of the present invention. 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 installing a joint forming plate member according to a preferred embodiment of the present invention (see FIGS. 8(a) and 8(b)) is used in a mountain tunnel construction method using tunnel lining concrete 4 (see FIG. 8) that covers the inner wall surface of a tunnel. 2, see Fig. 3) using the tunnel lining formwork 1 (see Figs. 1 to 3), joint formation for forming induced joints in the tunnel lining concrete 4 to be constructed. This method was adopted for installing the tunnel lining plate members 15, 15' (see FIG. 5) while supporting them on the tunnel lining formwork 1 (see FIG. 4). In this embodiment, the tunnel lining concrete 4 constructed to cover the inner circumferential surface of the excavated tunnel T is a tunnel lining formwork 1 called a center, which is generally used as a tunnel lining formwork 1 of about 10.5 m. Instead of having a construction extension, a long span tunnel lining form 1 having a construction extension of preferably about 18 m to 22 m is used to form the joint part forming plate members 15, 15. ' 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, and the construction is not carried out efficiently. Therefore, in this embodiment, a commonly used tunnel lining with a length of about 10.5 m is used. Instead of the long-span tunnel lining formwork 1, preferably having a construction extension of 10.5 m or more, for example, a long-span tunnel lining form 1 having an extension of about 18 to 22 m. By using this, the construction span of the concrete lining 4 that is carried out in one cycle is increased, and the concrete 12 is cast simultaneously from two systems of pressure-feeding piping 31 using two concrete pumps 30. By shortening the work time during pouring, it is possible to hasten the progress of the process for forming the lining concrete 4.

In addition, in this embodiment, when the length of the construction span of one cycle of the lining concrete 4 is increased by using the long-span tunnel lining formwork 1, 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 cannot be absorbed sufficiently, and cracks are likely to occur in the middle of the construction span. For this reason, joint forming plate members 15 and 15' are inserted into the slit-shaped gap δ in order to form joints that induce cracks due to drying shrinkage and temperature shrinkage in the middle part of the construction span (Fig. 4), a pair of divisions 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 body part 3 of the formwork 1 for tunnel lining. It is fixedly attached to the ends of the formwork main bodies 3A and 3B. The method for installing the joint forming plate members of this embodiment (see FIGS. 8(a) and 8(b)) is as follows: Each of the joint forming portions 15A is vertically erected from the formwork surface of the tunnel lining formwork 1 into the lining space S, and between the adjacent joint forming plate members 15 and 15'. This method was adopted as a method for accurately adjusting the standing angle and installing the joint forming portion 15A so that the joint forming portion 15A is continuous in the circumferential direction.

The method for installing the joint forming plate member of this embodiment is to install the plate member for forming a joint in the middle part in the axial direction Joint forming plate members 15, 15' (see FIGS. 5 and 6) for forming induced joints in tunnel lining concrete 4 to be constructed, which are removably attached, are attached when the poured concrete has hardened. This is an installation method for installing in a state where it can be pulled out later (see FIGS. 7(a) and 7(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 3 is composed of a plurality (in this embodiment, a pair) of split formwork main bodies 3A and 3B that are divided (in this 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 the divided formwork main bodies 3A and 3B. A plurality of joint forming plate members 15, 15' are each inserted into this slit-shaped gap δ (see FIG. 1), and the inserted joint forming plate members 15, 15' are on the outer peripheral side. With the joint forming part 15A (see FIG. 5) protruding into the lining space S, the inner protruding grip part 15B on the inner periphery side is preferably attached to the split formwork body on both sides with a slit-shaped gap δ in between. They are fixed to the parts 3A and 3B (see FIG. 4) and are attached in a continuous manner in the circumferential direction.

In the joint forming plate member 15, a pair of reaction force plates 63 each having a female threaded hole 63a projecting from both the front and back surfaces are fixed to the inner protruding grip part 15B at least at intervals in the circumferential direction. The bolt members 64 are each screwed into the female threaded holes 63a of the reaction force plate 63 at at least four locations (four locations in the present embodiment), and the tips thereof are attached to the ends of the bolt members 64. By moving these bolt members 64 forward and backward while rotating them while in contact with the substrate plate 25' fixed to the split formwork main bodies 3A and 3B, the joint forming plate members 15 and 15' are connected to the adjacent base plate 25'. The standing angle is adjusted so that the joint forming part 15A is continuous in the circumferential direction between the joint forming plate members 15 and 15'.

In this embodiment, the tunnel lining formwork 1 to which a plurality of joint forming plate members 15, 15' are attached to the intermediate portion serves as 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 constituting the gantry portion 2 includes a base portion 2a and support leg portions 2b that support the base portion 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. Side wall part 5
A pair of side formworks 3b for forming a lined space S in the upper part of the side wall part 55 and a pair of lower end formworks for forming a lined space S in the lower part of the side wall part 55 connected to the concrete of the invert part. 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 expand and contract the formwork body 3 by expanding and contracting the lifting jack 8 and the telescopic jacks 9a and 9b, and the tunnel lining The formwork main body 3 can be assembled along the inner peripheral 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.

In addition, in this 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 at two locations each at intervals in the excavation direction X of the tunnel T. (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 present embodiment, the formwork main body 3 of the tunnel lining formwork 1 is preferably divided into two parts in the excavation direction X of the tunnel T (horizontal direction in FIGS. 2 and 3), as described above. It is composed of a pair of split formwork main bodies 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, 15' for forming induced joints in the lining space S project the joint forming part 15A into the lining space S and are inserted and arranged in a removable manner. (See Figure 1).

In this embodiment, at least two locations (in the first embodiment Plate-side pin insertion holes 16a are formed at two locations (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 a pin member 26 (see FIG. 4), preferably having an outer diameter slightly smaller than the inner diameter of the plate side pin insertion hole 16a, into the matched plate side pin insertion hole 16a and end face pin insertion hole 23a, The joint forming plate members 15, 15' are supported between the end rib plates 21A, 21B on both sides, and are temporarily fixed in a tiltable manner.

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

In this embodiment, the joint forming plate members 15, 15' are preferably made of aluminum or steel, and have a thickness of about 6 to 10 mm (in this embodiment, 7 mm), as shown in FIGS. 5 and 6. It is formed using a metal plate with a thickness of approximately Further, the joint forming plate member 15 has an outer periphery having a vertical width of about 300 to 600 mm and a width of about 400 to 700 mm, and an inner periphery disposed opposite to the outer periphery. , and has a substantially four-sided planar shape having left and right side sides. The joint forming plate member 15 has an outer peripheral portion serving as a joint forming portion 15A that protrudes from the formwork surface into the lining space S, and an inner peripheral portion serving as a joint forming portion 15A. This is an inwardly protruding grip portion 15B that is arranged to protrude inside the frame body portion 3. In addition, in FIG. 5, the interval between the side edges that will be arranged on both circumferential edges of the split formwork main bodies 3A and 3B increases from the outer periphery side to the inner periphery side. A joint forming plate member 15' including a V-shaped portion is illustrated.

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, is a portion that is arranged 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 inward protruding grip part 15B has the above-mentioned plate side pin insertion hole 16a formed therein, so that the joint forming plate member 15 can be temporarily fixed until the concrete poured in the lining space S hardens. This part functions as a fixing part for keeping the concrete in place, and also functions as a handle part when pulling out the plate member 15 inside the form body part 3 after the concrete has hardened.

Further, as shown in FIGS. 5 and 6, a pair of reaction force plates 63 having female screw holes 63a are fixed to the inner protruding grip portion 15B by welding or the like, and extend vertically from both the front and back surfaces, respectively. installed. These pair of reaction force plates 63 are provided as at least two portions spaced apart in the circumferential direction at a portion closer to the inner periphery than the plate-side pin insertion hole 16a, preferably on both sides of the center line C in the width direction. They are arranged symmetrically and scattered in two parts. A bolt member 64 is attached to each of the four reaction force plates 63 in total, which is screwed into the female screw hole 63a from the inner peripheral side. Each bolt member 64 moves forward and backward by rotating with its tip in contact with the substrate plate 25 fixed to the divided formwork main body 3A, and moves the reaction plate 63 against the substrate plate 25. They can be displaced relative to each other (see FIGS. 4, 8(a) and 8(b)).

Furthermore, in this embodiment, concrete placed in the lining space S is placed 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 portion. After hardening, a pair of horizontally elongated rectangular handle openings 19 are provided, which function as handles when pulling out the joint forming plate members 15, 15' inside the divided formwork main bodies 3A, 3B. An opening is formed.

On the other hand, in this embodiment, each of the divided formwork body parts 3A and 3B on both sides of the slit-shaped gap δ into which the joint forming part 15A of the joint forming plate members 15 and 15' is inserted is A substrate plate 25 is fixedly supported by the end rib plates 21A, 12B and the reinforcing rib plates 24A, 24B (see FIGS. 4, 8(a) and 8(b)).

Moreover, in this embodiment, the joint forming portion 15A is made to protrude into the lining space S from the formwork surface formed by the outer peripheral surface of the split formwork main body parts 3A, 3B, and As shown in FIGS. 1 and 7, the plurality of joint forming plate members 15, 15' arranged in series are preferably arranged along the side edges of the joint forming portions 15A of each pair of adjacent plate members 15. The divided connection parts 15a, which are the boundary parts between the parts, are arranged continuously so that no gaps are formed. In addition, some of the plurality of joint forming plate members 15, 15' arranged in series are located between the side edges located on both sides of the divided formwork body parts 3A, 3B in the circumferential direction. The joint forming plate member 15' includes a V-shaped portion with a front shape that widens inwardly and whose spacing increases from the outer periphery side to the inner periphery side (see FIG. 5). .

A part of the plurality of joint forming plate members 15, 15' arranged in series in the circumferential direction is the joint forming plate member 15' including the V-shaped portion, so that the By pulling out the joint forming plate member 15' including the V-shaped portion in advance, the joint forming plate members 15 arranged continuously in the circumferential direction of the formwork main body 3 can be To enable each joint forming plate member 15 to be smoothly pulled out by avoiding difficulty in pulling out due to the side edges of the joint forming plate members 15 competing with each other at the split connection part 15a. becomes possible.

In the method for installing a joint forming plate member of the present embodiment, each joint forming plate member 15, 15' is formed between the adjacent ends of the split formwork body parts 3A, 3B. Insert into the slit-shaped gap δ (see Fig. 1), and with the joint forming part 15A (see Fig. 5) on the outer periphery side protruding into the lining space S, hold the inner protruding grip portion on the inner periphery side. 15B to the split formwork main bodies 3A, 3B (see FIG. 4), and when installing them in a continuous manner in the circumferential direction, these joint forming plate members 15, 15' are used to form adjacent joints. The standing angle can be easily adjusted and installed so that the joint forming portion 15A is continuous in the circumferential direction between the forming plate members 15 and 15'.

That is, in the present embodiment, each of the joint forming plate members 15, 15' has a pair of reaction forces having female screw holes 63a fixed to the inner protruding grip part 15B so as to protrude from both the front and back surfaces, respectively. The plates 63 are preferably arranged symmetrically on both sides of the center line C in the width direction, and are scattered at two locations. The tips of the bolt members 64 screwed into the four female threaded holes 63a of the reaction plates 63 are brought into contact with the substrate plates 25 fixed to the split formwork main bodies 3A, 3B. By moving the bolt member 64 forward and backward while rotating, the reaction plate 63 can be displaced relative to the base plate 25. As a result, each joint forming plate member 15, 15' is vertically moved from the form surface of the form main body 3 of the tunnel lining form 1 to the lining space S with the joint forming part 15A. The standing angle can be easily adjusted so that the joint forming part 15A can be erected with high accuracy, and the joint forming part 15A can be precisely continuous between the adjacent joint forming plate members 15 and 15' in the circumferential direction. This makes it possible to install them in series with high precision.

When the plurality of joint forming plate members 15, 15' are arranged and installed in the circumferential direction by the method of installing the joint forming plate members of this embodiment, the tunnel T covered with the primary lining 5 is Concrete is poured into a lining space S, which is a concrete placement space, formed between the inner peripheral surface and the formwork surface formed by the outer peripheral portion of the formwork main body 3 of the tunnel lining formwork 1. Then, work to construct tunnel lining concrete 4 is performed. In this 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 pipes 31 extending from two concrete pumps 30 to cover the tunnel. This can be done by simultaneously supplying the material to the work space S and pouring it.

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 addition, in this embodiment, once the concrete poured in the lining space S has hardened and the tunnel lining concrete 4 is formed, it is preferable to use the joint forming plate member described in Japanese Patent Application No. 2020-61496. By pulling out each of the plurality of joint forming plate members 15, 15' from the lining space S to the inside of the formwork main body 3 using the pulling out method, an induced joint is formed.

According to the method for installing a joint forming plate member of the present embodiment, each of the joint forming plate members 15 and 15' is attached to the formwork main body of the tunnel lining formwork 1, as described above. The joint forming part 15A is vertically installed in the lining space S from the formwork surface of No. 3, and the joint forming part 15A is continuous in the circumferential direction between the adjacent joint forming plate members 15 and 15'. Since the standing angle can be adjusted and installed with high accuracy, when removing the joint forming plate members 15, 15' after the concrete 4 poured in the lining space S has hardened, It becomes possible to avoid difficulty in pulling out the joint forming plate members 15, 15' from the concrete lining 4, and to smoothly remove the joint forming plate members 15, 15'.

In particular, the distance between the side edges on both sides in the circumferential direction, which are to be removed in advance among the joint forming plate members 15, 15' arranged in series in the circumferential direction, is The joint forming plate member 15', which includes a V-shaped portion that expands from the side toward the inner periphery, and the adjacent joint forming plate member 15 (see FIG. 7) are erected with high accuracy. If it is not attached, the joint forming part will shift in the front-rear direction and will not be continuous in the circumferential direction. When pulling out the adjacent joint forming plate member 15, the side edge portion gets caught in the hardened concrete at the shifted portion, making it difficult to pull out the adjacent joint forming plate member 15. However, according to the present embodiment, the joint forming plate member 15' including these V-shaped portions and the joint forming plate member 15 adjacent thereto are formed in a state in which the standing angle is precisely adjusted. Since they are attached in series, it is possible to effectively prevent these joint forming plate members 15, 15' from becoming difficult to pull out from the lining concrete 4.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made. 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 installation method of the present invention can also be employed when installing a joint forming plate member to be inserted into a slit-like gap between adjacent end portions.

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 portion 15B Inner protruding grip portion 16a Plate side pin insertion holes 21A, 21B End rib plate 23a End face pin insertion hole 25 Substrate plate 26 Pin member 63 Reaction force plate 63a Female screw hole 64 Bolt member δ Slit-shaped gap S Lining space T Tunnel X Tunnel excavation direction (axial direction of tunnel lining formwork)

Claims (2)

In the mountain tunnel construction method, a joint that forms an induced joint in the tunnel lining concrete to be constructed, which is removably attached to the axial middle part of the tunnel lining formwork that is installed when constructing the tunnel lining concrete. A method for installing a joint forming plate member for installing the joint forming plate member in a state where it can be pulled out after the poured concrete 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 so that it can be installed in a continuous manner in the circumferential direction. has become,
In the joint forming plate member, a pair of reaction plates each having a female threaded hole protruding from both the front and back surfaces are fixed to the inner protruding grip portion at least at two positions spaced apart in the circumferential direction. It is attached to
By screwing bolt members into the female threaded holes of the reaction plate at least four places, and moving the bolt members forward and backward while rotating the bolt members with their tips in contact with the main body of the split formwork. , a joint forming plate in which the standing angle of the joint forming plate member is adjusted and installed so that the joint forming part is continuous in the circumferential direction between adjacent joint forming plate members; How to install parts. The joint forming plate member, which is installed by adjusting the standing angle, is arranged such that the interval between the side edges located on both sides of the divided formwork main body in the circumferential direction is from the outer periphery side to the inner periphery side. Claim 1: A joint forming plate member including a V-shaped portion that expands toward the side, and a joint forming plate member disposed adjacent to the joint forming portion so as to be continuous in the circumferential direction. Installation method of the joint forming plate member described.