JP2022148753A - Removal method for plate member for forming joint part - Google Patents

Abstract

To provide a removal method for a plate member for forming a joint part, which can efficiently remove the plate member by allowing support reaction force to be obtained in stable conditions by a simple constitution when pulling out the plate member.SOLUTION: A plate member 15 for forming a joint part of a crown part 59 is removed by an extraction method using a wedge member 67, and the plate member 15 of a side wall part 55 is removed by an extraction method using a rod-like member 61. The extraction method using the wedge member 67 extracts the plate member 15 to the inside of a divided form body part 3A, 3B by relatively displacing the same to the inside of the divided form body part 3A, 3B relative to a reaction force plate 66 by driving the wedge member 67 to wedge engaging holes 65, 66a in the state where a plate-side wedge engaging hole 65 is placed to overlap a reaction force-side wedge engaging hole 66a such that it shifts outward in the radial direction.SELECTED DRAWING: Figure 7

Description

TECHNICAL FIELD The present invention relates to a method for removing a joint forming plate member, and more particularly to a method for removing joint forming plate members for forming induced joints in tunnel lining concrete in a mountain tunnel construction method. The present invention relates to a method for removing a forming plate member, and a method and a jig for removing a joint forming plate member that can be employed in the removing method.

For example, in tunnel construction methods such as the mountain tunnel construction method, a construction method that uses a tunnel lining formwork called centr as a method for forming tunnel lining concrete that is constructed by covering the natural ground on the inner peripheral surface of an excavated tunnel. is generally employed (see, for example, Patent Documents 1 and 2). For example, as shown in FIG. 12, the tunnel lining formwork 50 is installed along the inner peripheral surface of a tunnel 53 having a shape including an arch-shaped portion 52 such as a horseshoe, extending from the side wall portion 55 to the upper portion of the tunnel 53. Plain concrete is preferably placed in the lining space S′ between the installed tunnel lining formwork 50 and the natural ground covered with the shotcrete 54 on the inner peripheral surface of the tunnel 53. By casting and hardening, the tunnel lining concrete is formed so as to be continuous with the concrete of the inverted portion 51 at the bottom of the tunnel.

Further, as the tunnel lining formwork 50, for example, in addition to a prefabricated tunnel lining formwork called a bara center, a mobile tunnel lining formwork called a slide center is known. As the work progresses, the tunnel lining formwork 50 is re-installed every predetermined construction span of, for example, about 10.5 m, and the tunnel lining formwork is installed from the rear to the front in the direction of excavation of the tunnel 53. 50 is used to form the side and upper lining concrete of the tunnel 53 sequentially.

Then, in order to cast the lining concrete for the side and upper part of the tunnel using the tunnel lining formwork 50, for example, as shown in FIGS. As a height area where concrete can be cast from the inspection window 56 provided in the formwork 50, for example, the area from the side wall portion 55 of the tunnel 53 to the shoulder portion of the arch-shaped portion 52 is inspected through the inspection window 56. A vibrator 58 is inserted through the inspection window 56, and the concrete 57 is placed while compacting the supplied concrete 57 (see FIGS. 13(a) to 13(c)). After that, as a height region where it is difficult to compact with the vibrator 58 while supplying the concrete 57 from the inspection window 56, the crown portion 59 (see FIG. 12) of the tunnel 53 A pattern is adopted in which concrete 57 is press-fitted by a blow-up method from a blow-up input port 56' provided at the top end of the lining form 50, and poured to form the concrete 57 of the crown portion 59 (Fig. 13 ( d) see).

More specifically, after installing the tunnel lining formwork 50 at a predetermined position, for example, from the lower part of the side wall part 55, concrete 57 is poured through the lower inspection window 56 and compacted using the vibrator 58. (see FIG. 13(a)), and a step of compacting using a vibrator 58 while pouring concrete 57 through an inspection window 56 in the middle toward the arch-shaped portion 52 at the top of the side wall portion 55 (see FIG. 13 ( b)) and further up to just before the crown 59 of the arch-shaped portion 52, while pouring the concrete 57 through the upper inspection window 56 and, if necessary, the blow-up inlet 56', compact using the vibrator 58. In the step (see FIG. 13(c)), concrete 57 is forced into the crown 59 on the side of the existing lining concrete 4' through the blow-up inlet 56' by a blow-up method, and the concrete is poured up to the end formwork 63. The lining concrete is placed by the filling step (see FIG. 13(d)).

JP 2001-280094 A Japanese Patent Application Laid-Open No. 2003-262096 JP 2015-67949 A

On the other hand, in the tunnel construction method in recent years, due to improvements in excavation technology, the progress of the process for forming the lining concrete, from concrete placement to curing and removal of the formwork for the tunnel lining, affects the face surface of the tunnel. It is no longer possible to keep up with the progress of the excavation process. For this reason, as a technique for accelerating the progress of the process of forming lining concrete, a plurality of concrete pumps are used (see, for example, Patent Document 3), or a tunnel lining having a construction extension of about 10.5 m, which is generally used, is used. Instead of the construction formwork, a long-span tunnel lining formwork preferably having a construction extension of about 18m to 22m is used to extend the construction span of the tunnel lining concrete performed in one cycle, thereby shortening the construction period. is being considered to be shortened.

In addition, when using a long-span tunnel lining form having a construction extension of preferably about 18 m to 22 m and extending the construction span of the tunnel lining concrete performed in one cycle, 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, cracks due to drying shrinkage and temperature shrinkage are induced in the intermediate part. It is desirable to provide joints. For this reason, the applicant of the present application proposed, for example, Japanese Patent Application Laid-Open No. 2020-20246 as a method of providing an induced joint in the intermediate portion of the tunnel lining concrete. A plurality of joint forming plate members are arranged in series in the circumferential direction and attached so that they can be pulled out, and when the concrete cast in the lining space hardens, the joint forming plate members A method is disclosed for forming the induced joint by pulling from the lining space.

On the other hand, the operation of pulling out the joint forming plate member from the tunnel lining concrete that has been cast and hardened in the lining space is such that the joint forming portion of the joint forming plate member does not adhere to the hardened surrounding tunnel lining concrete. Because it is firmly attached, a large pulling force is required especially when first breaking off the adhesion between the joint forming part of the joint forming plate member and the hardened surrounding tunnel lining concrete. It is difficult to pull out the joint forming plate member only by manual work.

For this reason, various pull-out jigs such as lever blocks (registered trademark) have been used to pull out the joint forming plate member. It may be difficult to obtain the support reaction force when pulling out the joint forming plate member from various facilities and temporary members installed in the space, and depending on the location where the joint forming plate member is provided Therefore, it takes a lot of time and effort to provide a mechanism for stably obtaining the support reaction force.

Further, for example, in the crown portion 59 of the tunnel 53, since the joint forming plate member is pulled out downward, the pulled out joint portion forming plate member is likely to fall. Since the joint forming plate member is pulled out in the horizontal direction, it is difficult for the pulled out joint forming plate member to fall. By appropriately changing the pulling method according to the part, it is possible to more efficiently remove the plurality of joint forming plate members arranged in series in the circumferential direction.

The present invention makes it possible to easily obtain a supporting reaction force in a stable state by a simple structure when a joint forming plate member is pulled out inside a tunnel lining formwork, which requires a lot of labor. It is possible to remove each of the plurality of joint forming plate members continuously installed in the circumferential direction, and to remove them more efficiently by changing the pulling method according to the part in the circumferential direction of the tunnel. It is an object of the present invention to provide a method for removing a joint forming plate member that can be used continuously, and a method and jig for removing the joint forming plate member that can be employed in the removing method.

In the mountain tunnel construction method, the present invention is a tunnel lining concrete that is attached in a removable manner to an intermediate portion in the axial direction of a tunnel lining form that is installed when constructing the tunnel lining concrete. A joint forming plate member removal method for removing a joint forming plate member for forming a joint by pulling out and removing the joint forming plate member after the cast concrete has hardened, wherein the tunnel lining formwork is , a frame movable in the excavation direction of the tunnel, and a form body supported by the frame to form a lining space between itself and the inner wall surface of the tunnel, wherein the form body is , a plurality of split formwork bodies divided in the excavation direction of the tunnel, and between the adjacent ends of these split formwork bodies, slit-like gaps are formed continuously over the entire circumference. A plurality of the joint forming plate members are inserted into the slit-shaped gaps, and the inserted joint forming plate members are formed in the joint forming portion on the outer periphery side is protruding into the lining space, the inner protruding gripping portion on the inner peripheral side is fixed to the main body of the split formwork, and is continuously arranged in the circumferential direction and attached, and the tunnel lining concrete The joint forming plate member arranged at least in the crown portion of the tunnel lining concrete is adapted to be removed by a pulling method using a wedge member, and the joint portion arranged in at least the side wall portion of the tunnel lining concrete The forming plate member is to be removed by a pulling method using a rod-shaped member, and the pulling method using the wedge member is such that the plate side A wedge engagement hole is formed in advance, and a reaction force side wedge engagement hole is provided in the split formwork main body so as to be aligned with the inwardly projecting grip portion of the joint forming plate member. In a state in which the reaction plate is fixed, and the plate-side wedge engagement hole is arranged to overlap with the reaction-side wedge engagement hole while being displaced radially outwardly of the split mold body, By driving the wedge member into these wedge engagement holes, the joint forming plate member is relatively displaced toward the inner side of the split form main body with respect to the reaction plate, thereby displacing the split form. It is designed to be pulled out to the inside of the main body, and the pull-out method using the rod-shaped member is such that the action point projection is protruded and fixed to the inwardly projecting grip portion of the joint forming plate member. , the tip portion of the rod-shaped member is inserted between the point of application projection and the split form main body, and displaced in the rotational direction, so that the joint forming plate member is rotated by the principle of leverage. The above object is achieved by providing a method for removing a joint forming plate member that is displaced to the inside of a split formwork main body and pulled out to the inside of the split formwork main body. .

The present invention also provides a method for pulling out a joint forming plate member using a wedge member, which can be employed in the method for removing the joint forming plate member, wherein the joint forming plate member is pulled out. A plurality of plate-side wedge engagement holes are formed in the inwardly protruding gripping portion in a state in which the position of the joint portion forming plate member in the direction toward the outer peripheral portion is shifted from the inner peripheral portion, and One or a plurality of reaction plates having a reaction side wedge engagement hole at a portion corresponding to the plate side wedge engagement hole are provided in the split form main body, and the inner projecting grip portion of the joint forming plate member is provided. and one or more of the plate-side wedge engagement holes are positioned radially outward of the split form main body with respect to the reaction force-side wedge engagement holes. By driving the wedge members into these overlapping wedge engagement holes in a state where they are arranged so as to overlap with each other, the joint forming plate member is attached to the reaction plate by the split form main body and one or more of the other plate-side wedge engagement holes are displaced radially outward of the split form main body with respect to the reaction force-side wedge engagement holes By placing the wedge members so as to overlap each other and driving the wedge members into the wedge engagement holes that overlap each other in this state, the joint forming plate member is attached to the reaction plate and the main body of the split form. The joint forming plate member using a wedge member that is adapted to pull out the joint forming plate member to the inside of the split form main body by the step of relatively further displacing the joint forming plate member toward the inside of the It relates to a withdrawal method.

Furthermore, the present invention provides a method for pulling out a joint forming plate member using a rod-shaped member, which can be employed in the method for removing the joint forming plate member, wherein the joint forming plate member is pulled out. A pair of point-of-action projections are fixed to each of the front and back surfaces of the inwardly protruding gripping portion, and the point of action projections and the split formwork main body are fixed on both the front and back sides of the inwardly protruding gripping portion. By inserting the tip portions of a pair of rod-shaped members respectively between them and displacing these rod-shaped members in the rotational direction at the same time, the joint forming plate member is moved to the main body of the split form by the principle of leverage. The present invention relates to a method for pulling out a joint forming plate member using a rod-like member that is displaced inward and pulled out to the inside of the main body of the split formwork.

In the method of pulling out the joint forming plate member using the rod-shaped member of the present invention, the pair of action point protrusions sandwich the circumferential center line of the inner protruding holding portion of the joint forming plate member. Each of the pair of rod-like members is fixed to two parts on both sides so as to protrude from the front and back surfaces, and the tip parts of each pair of rod-shaped members are positioned from the outside between each of the action point projections and the split formwork main body. By inserting and displacing in the rotational direction, it is preferable that the joint forming plate member is displaced toward the inside of the main body of the split form by the principle of leverage.

Furthermore, the present invention is a pull-out jig used in a method for pulling out joint forming plate members using the rod-shaped members, wherein the pair of rod-shaped members allows insertion of the joint forming plate members. The present invention relates to a pull-out jig which is arranged in parallel while maintaining a gap width and is integrally fixed by being connected at one end thereof via a plate member.

According to the method for removing the joint forming plate member of the present invention, the support reaction force when pulling out the joint forming plate member inside the tunnel lining form can be easily and stably supported by a simple configuration. As a result, each of the plurality of joint forming plate members installed in series in the circumferential direction can be removed without much trouble, and the method of pulling out can be changed in the circumferential direction of the tunnel. By changing the part according to the part, it can be removed more efficiently.

2 is a schematic cross section of a tunnel lining form in which a plurality of joint forming plate members are arranged in series in the circumferential direction of the main body of the split form with the joint forming part protruding into the lining space; . FIG. 4 is a schematic vertical cross-sectional view for explaining a tunnel lining form to which a joint forming plate member is attached; FIG. 4 is a schematic plan view illustrating a tunnel lining form to which a joint forming plate member is attached; FIG. 3 is an enlarged cross-sectional view along AA in FIG. 1 at A' part in FIG. 2, explaining a mounting structure for mounting the joint forming plate member to the tunnel lining form. It is a front view of a plate member for joint part formation. FIG. 6 is a side view of the joint forming plate member (a view of FIG. 5 viewed from the left). (a) to (d) are explanatory diagrams of a method of pulling out a joint forming plate member using a wedge member. (a) and (b) are explanatory diagrams of a method of pulling out a joint forming plate member using a rod-shaped member, and (c) is a cross-sectional view taken along line BB in (a). (a) to (d) are explanatory diagrams of another preferred drawing method of the joint forming plate member using the wedge member. FIG. 10 is an explanatory diagram of another preferred method of pulling out the joint forming plate member using a rod-shaped member. FIG. 4 is a plan view illustrating a rod-shaped member; FIG. 5 is a schematic cross-sectional view illustrating a state in which a tunnel lining formwork is installed along the inner peripheral surface of a tunnel in a conventional method for placing tunnel lining concrete. 1(a) to 1(d) are schematic side views, partly in cross-section, for explaining the work procedure of a conventional tunnel lining concrete placing method.

A method for removing a joint forming plate member according to a preferred embodiment of the present invention is a method of removing a tunnel lining concrete 4 (see FIGS. 2 and 3) covering the inner wall surface of a tunnel in a mountain tunnel construction method. When constructing using the formwork 1 (see FIGS. 1 to 3), the joint forming plate member 15 (see FIG. 4) for forming an induced joint in the tunnel lining concrete 4 to be constructed is covered. This is adopted as a method for pulling out and removing from the tunnel lining concrete 4 after the concrete placed in the work space S hardens. In this embodiment, the tunnel lining concrete 4 constructed to cover the inner peripheral surface of the excavated tunnel T is used as a tunnel lining formwork 1 called a center, and has a thickness of about 10.5 m. Instead of having a construction extension, it is preferably formed using a long-span tunnel lining formwork 1 having a construction extension of about 18 m to 22 m. It is installed as a member for forming an induced joint that induces cracks due to drying shrinkage and temperature shrinkage in the intermediate portion of the construction span of the constructed tunnel lining concrete 4 .

That is, in the mountain tunnel construction method in recent years, due to improvements in excavation technology, the progress of the process for forming the lining concrete 4 from concrete placement to curing and removal of the tunnel lining formwork 1 is Since it is often impossible to keep up with the progress of the process of excavating the face of T, and it is often not constructed efficiently, in this embodiment, a tunnel lining having an extension of about 10.5 m, which is generally used For example, a long-span tunnel lining formwork 1 having an extension of about 18 to 22m is preferably used as a long-span tunnel lining formwork 1 having a construction extension of 10.5 m or more instead of a formwork for construction. By using it, the construction span of the lining concrete 4 performed in one cycle is increased, and by using two concrete pumps 30 to simultaneously cast the concrete 12 from two systems of pressure-feeding pipes 31, the concrete 12 is poured. By shortening the work time for placing, the progress of the process for forming the lining concrete 4 can be hastened.

In addition, in this 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, only at the boundary between the adjacent construction spans, the concrete Cracks due to drying shrinkage and temperature shrinkage cannot be sufficiently absorbed, and cracks are likely to occur in the middle part of the construction span. For this reason, a joint forming plate member 15 for forming an induced joint that induces cracking due to drying shrinkage or temperature shrinkage is inserted into the slit-shaped gap δ in the intermediate portion of the construction span (see FIG. 4). , a pair of split formwork main bodies that are arranged in series 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 tunnel lining formwork 1. It is fixedly attached to the ends of the parts 3A, 3B. The method of removing the joint forming plate member of the present embodiment is performed when the joint forming plate member 15 is pulled out from the hardened concrete after the concrete placed in the lining space S has hardened to form an induced joint. In addition, each of the plurality of joint forming plate members 15 installed in series in the circumferential direction can be efficiently installed by making it possible to easily obtain a support reaction force in a stable state without much trouble. It was adopted as a method that enables to pull out and remove well and to remove more efficiently by appropriately changing the method of pulling out.

The method for removing the joint forming plate member of the present embodiment is the tunnel lining formwork 1 (Fig. 1 ~ see Fig. 3), joint forming plate member 15 (Figs. 5 and 6) for forming an induced joint in the tunnel lining concrete 4 to be constructed, attached removably to the intermediate portion in the axial direction X. ) is removed by pulling it out after the placed concrete has hardened.

As shown in FIGS. 1 to 3, the tunnel lining formwork 1 is placed between a pedestal 2 movable in the tunnel excavation direction X and the inner wall surface of the tunnel T supported by the pedestal 2. A form main body 3 forming a lining space S is provided. The formwork main body 3 is composed of a plurality of split formwork main bodies 3A and 3B (one pair in this embodiment) divided (in this embodiment, into two) in the tunnel excavation direction. A slit-like gap δ (see FIG. 4) is continuously formed over the entire circumference between the adjacent ends of the split formwork main bodies 3A and 3B. A plurality of joint forming plate members 15 are respectively inserted into the slit-shaped gaps δ (see FIG. 1), and the inserted joint forming plate members 15 are formed into joint forming portions 15A on the outer periphery side. (see FIG. 5) protruding into the lining space S, the inner protruding gripping portion 15B on the inner peripheral side is preferably fixed to the split formwork main bodies 3A and 3B on both sides across a slit-shaped gap δ. (see FIG. 4), and are mounted in series in the circumferential direction.

At least the crown portion 59 of the tunnel lining concrete 4, preferably the joint forming plate member 15 arranged in the arch-shaped portion 52 other than the side wall portion 55, is removed by a pulling method using a wedge member 67, which will be described later. In addition, the joint forming plate member 15 arranged at least on the side wall portion 55 of the tunnel lining concrete 4 is removed by a pulling method using a rod-like member 61, which will be described later.

The extraction method using the wedge member 67 is, as shown in FIGS. In addition, a reaction plate 66 having a reaction side wedge engagement hole 66a is arranged along the inner protruding grip portion 15B of the joint forming plate member 15 on the split mold body portions 3A and 3B. In this state, the plate-side wedge engagement hole 65 is arranged to overlap with the reaction force-side wedge engagement hole 66a while being displaced radially outwardly of the split formwork main bodies 3A and 3B (Fig. 7). (b)), by driving a wedge member 67 into these wedge engaging holes 65 and 66a, the joint forming plate member 15 is moved to the inside of the split form main bodies 3A and 3B with respect to the reaction plate 66. They are relatively displaced (see FIG. 7(d)) and pulled out to the inside of the split mold body portions 3A and 3B.

As shown in FIGS. 8(a) to 8(c), the pull-out method using the rod-shaped member 61 is performed by projecting and fixing the action point projection 60 to the inward projecting grip portion 15B of the joint forming plate member 15. Then, the tip portion 61a of the rod-shaped member 61 is inserted between the point of action projection 60 and the split mold body portions 3A and 3B, and displaced in the rotational direction R (see FIG. 8A) (see FIG. 8A). 8(a)), the joint forming plate member 15 is displaced inside the split form main bodies 3A, 3B by the principle of leverage (see FIG. 8(b)), and the split form main bodies 3A, It is designed to be pulled out inside 3B.

In this embodiment, the tunnel lining formwork 1 having a plurality of joint forming plate members 15 attached to the intermediate portion is a slide center that can move 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 22m. The tunnel lining formwork 1 has substantially the same configuration as the tunnel lining formwork described in, for example, Japanese Patent Application Laid-Open 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 is connected and integrated in the excavation direction X (see FIG. 2) of the tunnel T, and the frame part 2 is formed by a plurality of gate-type carriages 2A. , are supported by the gantry 2 of these integrated portal carriages 2A and are arranged along the inner peripheral surface of the tunnel T covered by a primary lining 5 of, for example, shotcrete (see FIG. 1). ), and a formwork main body 3 that forms the formwork surface inside the lining space S. A portal carriage 2A that constitutes the gantry section 2 includes a base section 2a and support leg sections 2b that support the base section 2a. At the lower ends of the support legs 2b, there are provided running portions 7 that can run along rails 6 laid on the floor of the tunnel T. It can move in the excavation direction X.

The form body 3 is assembled so as to have a shape along the inner peripheral surface of the tunnel T covered by the primary lining 5, and is spaced apart from the inner peripheral surface of the tunnel T by a predetermined distance. By being arranged, a lining space S with a predetermined thickness is formed, which is a concrete placing space. 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 lower and both sides of the arch-shaped portion 52. A pair of side formwork 3b for forming the lining space S on the upper part of the side wall part 55, and a pair of lower end parts for forming the lining space S on the lower part of the side wall part 55 connected to the concrete of the inverted part. It is configured including the formwork 3c. The upper formwork 3a is supported vertically by a plurality of elevating jacks 8 provided on the base portion 2a of the portal carriage 2A that constitutes the gantry portion 2 so as to be vertically movable. The pair of side molds 3b are rotatably connected to the lower ends on both sides of the upper mold 3a via rotary couplings 3d, respectively. It is rotatably connected to the lower end of 3b via a lower rotary connecting portion 3e. One end of the side formwork 3b and the lower end formwork 3c are connected to the other ends of telescopic jacks 9a and 9b connected to the gate-type carriage 2A. Thus, the side molds 3b and the lower end molds 3c can be rotated with respect to the upper molds 3a and the side molds 3b.

As a result, the tunnel lining formwork 1 can expand and contract the formwork main body 3 by expanding and contracting the elevating jacks 8 and the telescopic jacks 9a and 9b. The formwork main body 3 can be assembled along the inner peripheral surface of the tunnel T, and the formwork main body 3 can be removed from the mold and then moved in the excavation direction X inside the tunnel T.

In the present 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 spaced apart in the excavation direction X of the tunnel T. (see FIG. 2). A plurality of zenith press-fit connection ports 27 are formed at two locations in the excavation direction X of the tunnel T at intervals in the ridge portion of the upper mold 3a of the mold main body 3 . These press-fitting connection ports 11a, 11b, and 27 are used for the purpose of pouring or press-fitting the lining concrete 12 pressure-fed through the pressure-feeding pipe 31 into the lining space S, as will be described later. Used.

In this embodiment, as described above, the formwork body 3 of the tunnel lining formwork 1 is preferably divided into two in the tunnel T excavation direction X (horizontal direction in FIGS. 2 and 3). It is composed of a pair of split mold 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 over the entire circumference between the adjacent end faces. It is In addition, in the formed slit-shaped gap δ, the end rib plates 21A and 21B forming the end faces of the pair of split form main bodies 3A and 3B are supported, and the middle of each work span (L = 18 m) is supported. A plurality of joint forming plate members 15 for forming an induced joint in a part are inserted and arranged in a state in which the joint forming part 15A protrudes into the lining space S and can be pulled out over the entire circumference. They are arranged in series (see FIG. 1).

In the present embodiment, there are at least two (in the first embodiment, 2), plate-side pin insertion holes 16a are formed (see FIG. 5). In the end rib plates 21A, 21B forming the end surfaces of the pair of split form main bodies 3A, 3B, the joint forming part 15A, which is the part on the outer peripheral side of the joint forming plate member 15, is provided as a lining space. End surface pin insertion holes 23a are formed at positions that match the plate-side pin insertion holes 16a in a state of protruding toward S (see FIG. 4). By inserting the pin members 26 (see FIG. 4) into the plate-side pin insertion holes 16a and the end surface pin insertion holes 23a that are aligned, the joint forming plate member 15 is attached to the end rib plates 21A and 21B on both sides. It is fixedly attached in a state of being sandwiched and supported.

Further, in this embodiment, as shown in FIG. 4, preferably, a pair of split formwork main bodies 3A and 3B, which are positioned on both sides of the slit-shaped gap .delta. Preferably, the face wooden members 22A and 22B having a right-angled triangular or right-angled trapezoidal cross-sectional shape protrude into the lining space S, preferably around the split form main bodies 3A and 3B. It is attached continuously along the entire circumference in the direction.

In this embodiment, as shown in FIGS. 5 and 6, the joint forming plate member 15 is preferably made of aluminum or steel and has a thickness of, for example, about 6 to 10 mm (about 7 mm in this embodiment). height) metal plate. In addition, the joint forming plate member 15 includes an outer peripheral 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 peripheral side portion facing the outer peripheral side portion. It has a substantially four-sided planar shape having side portions and left and right side portions. The joint forming plate member 15 has a joint forming portion 15A arranged so as to protrude from the formwork surface into the lining space S at the portion on the side of the outer peripheral side, and the portion on the side of the inner peripheral side. is an inner protruding grasping portion 15B which is arranged to protrude inside the form body portion 3. As shown in FIG.

As shown in FIG. 4, the joint forming portion 15A is provided so as to extend in the circumferential direction between the end rib plates 21A and 21B that form the end faces of the pair of split form main bodies 3A and 3B. In addition, when the joint forming plate member 15 is inserted toward the lining space S through the slit-shaped gap δ, from the formwork surface formed by the outer peripheral portions of the pair of split formwork main bodies 3A and 3B, , for example, is arranged to protrude outward with a protruding 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 inwardly protruding gripping portion 15B functions as a temporary fixing portion for fixing the joint portion forming plate member 15 until the concrete placed in the lining space S hardens, and after the concrete hardens. It is a part that functions as a handle when the plate member 15 is pulled out to the inside of the form body 3 . As shown in FIGS. 5 and 6, the inwardly protruding gripping portion 15B is arranged symmetrically on both sides of the center line C in the width direction at a portion adjacent to the joint forming portion 15A, and a pair of plate side A pin insertion hole 16a is formed. As described above, the pair of plate-side pin insertion holes 16a are arranged in a state in which the joint forming portion 15A of the joint forming plate member 15 protrudes into the lining space S. It is formed at a position corresponding to each of the pair of end face pin insertion holes 23a formed in the end rib plates 21A and 21B forming the (see FIG. 4). As a result, as described above, by inserting the pin members 26 (see FIG. 4) into the aligned plate-side pin insertion holes 16a and the end surface pin insertion holes 23a, the joint forming plate member 15 is formed into the split formwork. It is attached to the end rib plates 21A, 21B of the main bodies 3A, 3B in a supported state.

In addition, in this embodiment, in the portion of the inward protruding gripping portion 15B close to the inner peripheral side portion, it is placed symmetrically on both sides of the center line C in the lateral width direction and cast into the lining space S. After the concrete has hardened, the joint forming plate member 15 is pulled out to the inside of the split form main bodies 3A and 3B. It is

Furthermore, in this embodiment, the joint forming portion 15A is projected into the lining space S from the formwork surface formed by the outer peripheral surface portions of the split formwork main bodies 3A and 3B in the circumferential direction of the split formwork main bodies 3A and 3B. As shown in FIG. 1, each of the plurality of joint forming plate members 15 arranged in series preferably has a split connection portion which is a boundary portion between the side portions of each pair of adjacent plate members 15. 15a are continuously arranged so as not to form a gap. In some of the plurality of joint forming plate members 15 arranged in series, the interval between the side portions on both sides of the lining space S is oriented from the outer peripheral side to the inner peripheral side. It is a plate member including a V-shaped plate portion having a front shape that widens toward the inside (see FIG. 5).

Some of the plurality of joint portion forming plate members 15 arranged in series in the circumferential direction are such that the interval between the side portions on both sides widens toward the inner peripheral side of the lining space S. Since the plate member 15' includes the V-shaped plate portion, the plate member 15' including the V-shaped plate portion is pulled out first, so that the formwork main body 3 is extended in the circumferential direction. The plate members 15 arranged in series are arranged so that each plate member 15 can be smoothly pulled out by avoiding difficulty in pulling out due to competition between the side parts of the adjacent plate members 15 at the split connection part 15a. 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 form main bodies 3A and 3B. By inserting each joint portion forming plate member 15 continuously in the circumferential direction and attaching it, the inner peripheral surface of the tunnel T covered by the primary lining 5 and the mold of the tunnel lining formwork 1 Concrete is placed in a lining space S, which is a space for placing concrete, which is formed between the outer peripheral portion of the frame body 3 and the formwork surface, to construct the tunnel lining concrete 4. be In the present embodiment, as shown in FIGS. 2 and 3, the work of constructing the tunnel lining concrete 4 consists of concrete that is pumped from two concrete pumps 30 via pumping pipes 31 extending from each of the concrete pumps 30. It can be carried out by placing while simultaneously supplying to the working space S.

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

Two systems of pumping pipes 31 extending from the two concrete pumps 30 are a main pipe 31a extending toward the inside of the tunnel lining formwork 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 including left and right branch pipes 31b branched on both sides. Here, each of the branch pipes 31b includes a plurality of piece pipes made up of straight pipes, curved pipes, etc., having different lengths. are arranged to be connected to each other. Further, by rearranging these piece pipes, the branch pipe 31b is preferably formed at the rear end of each of the split formwork main bodies 3A and 3B, which are divided into two parts of the formwork main body 3, in the excavation direction X. In addition, the lower press-fit connection port 11a is switched to the upper press-fit connection port 11b, or the upper press-fit connection port 11b is switched to the zenith press-fit connection port 27 to place the concrete 12. It is possible to do so.

After the concrete placed in the lining space S hardens and the tunnel lining concrete 4 is formed, a plurality of joint forming plate members are removed by the joint forming plate member removal method of the present embodiment. 15 are pulled out from the lining space S to the inside of the form body 3 to form an induced joint. In the removal method of the present embodiment, as described above, at least the crown portion 59 of the tunnel lining concrete 4, preferably the joint portion forming plate member 15 arranged in the arch-shaped portion 52 other than the side wall portion 55, is 7(a) to 7(d), the joint portion forming plate member 15 arranged on the side wall portion 55 of the tunnel lining concrete 4 is removed by a pulling method using the wedge member 67, It is designed to be removed by a pulling method using a rod-like member 61 shown in FIGS. 8(a) to 8(c).

In the extraction method using the wedge member 67, as shown in FIGS. 7(a) to 7(d), the plate-side wedge engagement hole 65 is formed in the inward projecting grip portion 15B of the joint forming plate member 15. In addition, a reaction plate 66 having a reaction side wedge engagement hole 66a is arranged along the inner protruding grip portion 15B of the joint forming plate member 15 in the split mold body portions 3A and 3B. keep it fixed. As shown in FIGS. 7(a) and 7(b), the plate side wedge engagement hole 65 is displaced radially outward of the split form main bodies 3A and 3B with respect to the reaction force side wedge engagement hole 66a. (see FIG. 7(b)), and by driving a wedge member 67 into the overlapping wedge engagement holes 65 and 66a, the joint forming plate member 15 is joined to the split mold body portions 3A and 3B. It is possible to generate a force in the pulling direction Z to the inside of the joint portion forming plate member 15 and move the joint portion forming plate member 15 slightly relative to the reaction plate 66 (FIGS. 7(c) and (d) reference).

When the joint forming plate member 15 is slightly moved in the pulling direction Z by the force in the direction Z in which the joint forming plate member 15 is pulled out inward, the joint forming portion 15A and the hardened surrounding tunnel lining concrete are separated from each other. Since the adhesion state with is cut off and released, the joint part forming plate member 15 after the adhesion state is cut off can be smoothly pulled out to the inside of the split form body parts 3A and 3B, possible to remove.

In the extraction method using the wedge member 67, the wedge member 67 driven into the overlapping wedge engagement holes 65 and 66a cuts off the adhesion state between the joint forming portion 15A and the surrounding tunnel lining concrete. After that, since the state of being driven into the overlapping wedge engagement holes 65 and 66a is maintained, the pulled-out joint forming plate member 15 is not attached to the arch-shaped portion 52 including the crown 59 other than the side wall portion 55. Even if it is arranged and pulled out downward, it is possible to effectively avoid that it accidentally falls downward due to its own weight after the attached state is cut off. .

On the other hand, in the pulling method using the rod-shaped member 61, as shown in FIGS. A pair of action point projections 60 are provided symmetrically on both sides of the center line C (see FIG. 5) in the width direction. The point-of-action projection 60 is a cylindrical portion made of steel having a diameter of, for example, about 20 mm. It protrudes at a certain height and is attached integrally by, for example, welding or the like. The action point protrusion 60 is detachably fixed to the inner protruding grip portion 15B by, for example, fitting or screwing into a mounting fixing hole formed in the inner protruding grip portion 15B of the joint forming plate member 15. can also On each point of action projection 60, a tip portion 61a of a rod-shaped member 61 preferably made of a steel rod is attached to a base plate 25 (Figs. 8(a) and 8(b)) preferably fixed to one of the split mold body portions 3A. ) is inserted into the gap between and engaged.

Further, in the present embodiment, among the split form main body portions 3A and 3B on both sides of the slit-shaped gap δ into which the joint forming portion 15A of the joint forming plate member 15 is inserted, for example, the action point projections 60 is supported by the end rib plate 21A and the reinforcing rib plate 24A, and the substrate plate 25 is fixed (see FIGS. 8(a) and 8(b)). A strip-shaped erecting fulcrum plate 62 is erected from the base plate 25 inside the split form main body 3A, and is integrally attached by, for example, welding or the like. A recessed support portion 62a curved in a recessed shape is formed at the leading end of the standing fulcrum plate 62 (see FIG. 8(c)).

In this embodiment, the side peripheral surface of the tip portion 61a of the bar-shaped member 61 made of a steel bar is brought into contact with the erected fulcrum plate 62 along the concave support portion 62a at the tip, and the bar-shaped member 61 is placed 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 form main body 3A. From the inserted state (see FIG. 8(a)) by forcing it in, the rod-shaped member 61 is rotated in the rotational direction indicated by R in the figure, using the recessed support portion 62a of the erected fulcrum plate 62 as a fulcrum. can be displaced. As a result, the joint portion forming plate member 15 is separated from the split formwork by the principle of leverage with the tip of the tip portion 61a of the rod-like member 61 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 pull-out force in the direction Z to the inside of the body portion 3A, by pulling out the joint-forming plate member 15, the joint-forming portion 15A and the hardened It is possible to cut off the adhesion state with the surrounding tunnel lining concrete. Further, the joint portion forming plate member 15 after the adhesion state is cut off can be smoothly pulled out to the inside of the split mold body portions 3A and 3B and removed.

Here, in the drawing method using the rod-shaped member 61, compared to the drawing method using the wedge member 67, the joint portion forming plate member 15 is larger than the drawing method using the wedge member 67 by the principle of leverage. In addition, it is possible to move the joint forming plate member 15 in the pulling direction Z more easily and greatly. Further, since the joint forming plate member 15 arranged on the side wall portion 55 is to be pulled out in the horizontal direction, it is in a state in which it is difficult to fall due to its own weight even if the adhered state is cut off. As a result, it is possible to perform the work of removing the joint forming plate member 15 more rapidly and in a short period of time, preferably while pulling it out all at once.

In addition, in the drawing method using the rod-shaped member 61, it is not always necessary to use the erecting fulcrum plate 62 having the recessed support portion 62a at the tip portion, which is erected from the substrate plate 25 fixed to the split mold main body portion 3A. . For example, the tip portion of the tip portion 61a of the rod-shaped member 61 is forcibly inserted between the action point protrusion 60 of the joint forming plate member 15 and the substrate plate 25 fixed to the split form main body portion 3A. From this state, the rod-shaped member 61 is rotated and displaced in a direction R′ opposite to the rotation direction indicated by R in FIG. can also As a result, the joint portion forming plate member 15 is moved to the inside of the split form main body 3A by the principle of leverage with the side portion of the tip portion of the tip portion 61a of the rod-shaped member 61 coming into contact with the action point projection 60 as the point of action. By generating a pull-out direction Z force and moving the joint forming plate member 15 in the pull-out direction Z, the joint portion forming portion 15A of the joint portion forming plate member 15 and the hardened surrounding tunnel lining concrete are separated. may be removed by cutting off the adhered state of the .

According to the method for removing the joint forming plate member of the present embodiment, the support reaction force when pulling out the joint forming plate member 15 inside the tunnel lining form 1 is stabilized by a simple configuration. It is possible to remove each of the plurality of joint forming plate members 15 continuously installed in the circumferential direction without much trouble by making it possible to easily obtain it in a state where it is attached. By changing the method of pulling out according to the part in the circumferential direction of the tunnel, it becomes possible to remove it more efficiently.

That is, according to this embodiment, at least the crown portion 59 of the tunnel lining concrete 4, preferably the joint portion forming plate member 15 arranged in the arch-shaped portion 52 other than the side wall portion 55, is replaced by the wedge member 67 described later. , and the joint forming plate member 15 disposed on at least the side wall portion 55 of the tunnel lining concrete 4 is removed by a pulling method using a rod-shaped member 61, which will be described later. The extraction method using the wedge member 67 is to form a plate-side wedge engagement hole 65 in the inward projecting grip portion 15B of the joint forming plate member 15, and a split mold A reaction plate 66 having a reaction side wedge engagement hole 66a is fixed to the frame main body portions 3A and 3B so as to be arranged along the inner projecting grip portion 15B of the joint forming plate member 15, The plate-side wedge engagement hole 65 of the inward projecting grip portion 15B of the joint forming plate member 15 is aligned with the reaction force-side wedge engagement hole 66a of the reaction plate 66 in the radial direction of the split mold body portions 3A and 3B. By driving a wedge member 67 into these wedge engagement holes 65 and 66a in a state of being overlapped with being shifted outward, the joint forming plate member 15 is pushed against the reaction plate 66 into the main body of the split formwork. 3A, 3B are relatively displaced to the inside of the split formwork main bodies 3A, 3B, and pulled out to the inside of the split formwork main bodies 3A, 3B. By inserting between the point of action projection 60 and the split form main bodies 3A, 3B and displacing in the rotational direction R, the joint forming plate member 15 is moved to the split form main bodies 3A, 3B by the principle of leverage. 3B to be pulled out to the inside of the split mold main bodies 3A and 3B.

As a result, according to the method for removing the joint forming plate member of the present embodiment, the split form main bodies 3A and 3B of the tunnel lining form 3 are separated from the split form main bodies 3A and 3B inside the split form main bodies 3A and 3B. Since the support reaction force when pulling out the joint forming plate member is directly obtained via the reaction force plate 66, the substrate plate 25, and the standing fulcrum plate 62, the inside of the tunnel lining formwork 3 Without obtaining support reaction force from various facilities provided in the It is possible to efficiently pull out and remove each of the plurality of joint forming plate members 15 installed in the same direction. Further, at least for the crown portion 59 where the joint forming plate member 15 is likely to fall, a more stable extraction method using a wedge member 67 is adopted according to the portion in the circumferential direction of the tunnel so that the joint forming plate member 15 can be pulled out. At least the side wall portion 55, which is difficult to fall, can be pulled out in a short time using the rod-shaped member 61. By changing the method of pulling out the joint forming plate member 15, joint formation can be performed more efficiently. It becomes possible to remove the plate member 15 for use.

Further, in the present embodiment, as a method of pulling out the joint forming plate member 15 using the wedge member 67, which can be employed in the method of removing the joint forming plate member described above, preferably, FIG. ) to (d), the inner protruding grip portion 15B of the joint forming plate member 15 is displaced from the inner peripheral portion of the joint forming plate member 15 toward the outer peripheral portion. , Plate-side wedge engagement holes 65 are formed at a plurality of locations (in this embodiment, a total of 5 locations shifted by 3 stages) (see FIGS. 9(b) to 9(c)), and the split mold body portion In 3A and 3B, one or a plurality of reaction plates 66 (three reaction plates in this embodiment) provided with reaction side wedge engagement holes 66a at portions corresponding to the plate side wedge engagement holes 65, It can be arranged and fixed so as to be along the inward projecting grip portion 15B of the joint forming plate member 15 (see FIG. 9A). One or two or more predetermined plate-side wedge engagement holes 65 (in this embodiment, two locations on both sides of the lower stage, which is the innermost peripheral side, see the black part in FIG. 9B) are on the reaction force side It is arranged so as to overlap with the wedge engagement holes 66a (in this embodiment, the reaction side wedge engagement holes of the reaction plates 66 on the left and right sides) while being displaced radially outward of the split formwork main bodies 3A and 3B. 7(a) and 7(b)), a wedge member 67 (see FIGS. 7(a) to 7(d)) is driven into these overlapping wedge engaging holes 65 and 66a to form a joint portion. While displacing the forming plate member 15 relative to the reaction plate 66 toward the inside of the split formwork main bodies 3A and 3B (see FIGS. 7(c) and 7(d)), one or more other The plate-side wedge engagement hole 65 (in this embodiment, one place in the central part of the middle row, see the black-painted part in FIG. 9(c)) corresponds to the reaction force-side wedge engagement hole 66a (in this embodiment, the center The split mold frame main bodies 3A and 3B are displaced radially outward from the reaction force side wedge engagement hole of the reaction force plate 66 and overlapped with each other. By driving a wedge member 67 into these overlapping wedge engagement holes 65 and 66a in this state, the joint portion forming plate member 15 is moved toward the inside of the split mold body portions 3A and 3B with respect to the reaction plate 66. Preferably, the step of further displacing the joint portion is repeated as necessary, so that the joint portion forming plate member 15 can be successively pulled out to the inside of the split mold body portions 3A and 3B. . In this embodiment, while the joint forming plate member 15 is further displaced toward the inside of the split formwork main bodies 3A and 3B with respect to the reaction plate 66, one or more plate-side wedge engagement members are further displaced. The joint holes 65 (in this embodiment, two places on both sides of the upper stage, which is the outermost side, see the black part in FIG. 9(d)) are the reaction force side wedge engagement holes 66a (in this embodiment, Since the split form main bodies 3A and 3B are displaced radially outwardly of the split formwork main bodies 3A and 3B with respect to the reaction force side wedge engaging holes of the reaction force plates 66 on both the left and right sides, the overlapping wedges are arranged to overlap each other. By driving the wedge member 67 into the engagement holes 65 and 66a, the joint forming plate member 15 is relatively displaced toward the inner side of the split form main bodies 3A and 3B with respect to the reaction plate 66. becomes possible.

As a result, in the method of pulling out the joint forming plate member 15 using the wedge member 67 shown in FIGS. It is possible to gradually pull out the joint forming plate member 15, and to increase the pulling amount by the wedge member 67, so that the joint forming plate member 15 can be pulled out reliably.

Furthermore, in the present embodiment, as a method of pulling out the joint forming plate member using a rod-shaped member 61, which can be employed in the method of removing the joint forming plate member described above, preferably as shown in FIG. Then, a pair of action point projections 60 are fixed by projecting from both the front and back surfaces of the inwardly protruding gripping portion 15B of the joint forming plate member 15, and the action The tip portions 61a of a pair of rod-shaped members 61 are respectively inserted between the point projections 60 and the split formwork main bodies 3A and 3B, and these rod-shaped members 61 are displaced in the rotational direction R at the same time. By displacing the joint forming plate member 15 to the inside of the split form main bodies 3A and 3B, it is also possible to pull out to the inside of the split form main bodies 3A and 3B.

As a result, it becomes possible to pull out the joint forming plate member 15 using the rod-shaped member 61 in a more stable state, and the distortion that occurs when the joint forming plate member 15 is pulled out can be effectively reduced. can be effectively suppressed.

Also, at this time, the pair of action point projections 60 are preferably provided at two portions on both sides of the inner projecting grip portion 15B of the joint forming plate member 15 sandwiching the circumferential center line (Fig. 8(a), ( See b)), each projecting from both the front and back surfaces and fixed, and the tip portions 61a of each pair of rod-shaped members 61 are inserted from the outside between the respective action point projections 60 and the split formwork main bodies 3A and 3B. , and displaced in the rotational direction R, the joint forming plate member 15 can be displaced toward the inside of the split formwork main bodies 3A and 3B by the principle of leverage.

Further, in the present embodiment, a pair of rod-shaped members 61 are used as the pull-out jig 68 used in the method of pulling out the joint forming plate member 15 using such a pair of rod-shaped members 61 as shown in FIG. It is possible to use a jig in which one end is connected via a plate member 68a and integrally fixed in a state where the joint forming plate members 15 are arranged in parallel while maintaining a gap width that allows insertion of the joint portion forming plate member 15. preferable.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the main body of the tunnel lining form does not necessarily have to be divided into two, and may be divided into three or more. When the joint forming plate member inserted into the slit-shaped gap between the adjacent ends is pulled out after the concrete hardens and removed, the joint forming plate member removal method of the present invention can be used. can be adopted.

1 Tunnel lining form 2 Mounting frame 3 Form body 3A, 3B Split form body 4 Tunnel lining concrete (lining concrete)
15 Joint forming plate member 15A Joint forming part 15B Inner protruding grip part 16a Plate side pin insertion holes 21A and 21B End rib plate 23a End face pin insertion hole 25 Board plate 26 Pin member 60 Action point projection 61 Rod member 61a Tip Portion 62 Standing fulcrum plate 62a Concave support portion 65 Plate-side wedge engagement hole 66 Reaction plate 66a Reaction-side wedge engagement hole 67 Wedge member 68 Drawing jig δ Slit-shaped gap S Lining space T Tunnel X Tunnel Excavation direction (axial direction of formwork for tunnel lining)
Z Direction of pulling out the joint forming plate member

Claims (5)

In the mountain tunnel construction method, an induced joint is formed in the tunnel lining concrete to be constructed, which is attached so as to be able to be pulled out to the intermediate part in the axial direction of the tunnel lining form installed when constructing the tunnel lining concrete. A method for removing a joint forming plate member for removing the joint forming plate member for removing the joint forming plate member by pulling it out after the cast concrete has hardened,
The tunnel lining formwork includes a pedestal that is movable in the tunnel excavation direction, and a formwork main body that is supported by the pedestal and forms a lining space between itself and the inner wall surface of the tunnel. cage,
The formwork main body is composed of a plurality of split formwork main bodies divided in the excavation direction of the tunnel, and slit-like gaps are formed between adjacent ends of these split formwork main bodies. It is formed continuously over the entire circumference, and a plurality of the joint forming plate members are inserted into the slit-shaped gaps. With the joint forming part on the side projecting into the lining space, the inner protruding gripping part on the inner peripheral part side is fixed to the main body part of the split form, and attached in a continuous manner in the circumferential direction. cage,
The joint forming plate member arranged at least on the crown portion of the tunnel lining concrete is removed by a pulling method using a wedge member, and is arranged on at least the side wall portion of the tunnel lining concrete. The joint forming plate member is to be removed by a pulling method using a rod-shaped member,
In the drawing method using the wedge member, a plate-side wedge engagement hole is formed in the inwardly projecting grip portion of the joint forming plate member, and the joint formation is performed in the split form main body. A reaction plate having a reaction side wedge engagement hole is arranged along the inner protruding grip portion of the plate member for fixing, and the plate side is fixed to the reaction side wedge engagement hole In a state in which the wedge engagement holes are arranged to overlap with each other while being shifted radially outwardly of the main body of the split formwork, the wedge member is driven into the wedge engagement holes to form the joint forming plate member. Displaced toward the inside of the main body of the split formwork relative to the reaction plate and pulled out to the inside of the main body of the split formwork,
In the pulling method using the rod-shaped member, an action point projection is protruded and fixed to the inward projecting grip portion of the joint forming plate member, and the tip portion of the rod-shaped member is attached to the action point projection. By inserting it between the split form main body and displacing it in the rotational direction, the joint forming plate member is displaced inside the split form main body by the principle of leverage, and the split A method for removing a joint forming plate member that is pulled out to the inside of a form body. A method for pulling out a joint forming plate member using a wedge member, which can be employed in the method for removing the joint forming plate member according to claim 1,
A plurality of plate-side wedge engagement holes are formed in the inward projecting holding portion of the joint forming plate member in a state in which the position of the joint forming plate member is shifted in the direction from the inner peripheral portion to the outer peripheral portion thereof. and one or more reaction plates provided with reaction side wedge engagement holes at portions corresponding to the plate side wedge engagement holes in the split form main body for forming the joint portion It is arranged and fixed so as to be along the inward projecting grip portion of the plate member, and one or two or more predetermined plate-side wedge engagement holes are separated from the reaction force side wedge engagement holes. By driving the wedge members into the overlapping wedge engagement holes in a state where they are overlapped with each other while being displaced radially outwardly of the form body, the joint forming plate member is attached to the reaction plate. In addition, one or more of the plate-side wedge engagement holes are relatively displaced toward the inside of the split form main body, and the one or more other plate-side wedge engagement holes are aligned with the split form main body with respect to the reaction force-side wedge engagement holes. By driving the wedge member into the overlapping wedge engagement holes in this state, the plate member for forming the joint portion is attached to the reaction plate. On the other hand, a wedge member is used to pull out the joint forming plate member to the inside of the split form main body by the step of relatively further displacing it toward the inside of the split form main body. A method for pulling out a plate member for forming a damaged joint. A method for pulling out a joint forming plate member using a rod-shaped member, which can be employed in the method for removing the joint forming plate member according to claim 1, wherein the joint forming plate member is pulled out. A pair of point-of-action projections are fixed to the inwardly protruding gripping portion so as to protrude from both the front and back surfaces, respectively, and on both the front and back sides of the inwardly protruding gripping portion, the point-of-action projection and the split formwork main body are connected. By inserting the tip portions of a pair of rod-shaped members respectively between them and displacing these rod-shaped members in the rotational direction at the same time, the joint forming plate member is moved to the inside of the main body of the split form by the principle of leverage. A method for pulling out a joint forming plate member using a rod-shaped member adapted to be displaced to the inside of the main body of the split form and pulled out. The pair of action point protrusions are fixed to two portions on both sides across the circumferential center line of the inner protruding grip portion of the joint forming plate member so as to protrude from the front and back surfaces, respectively. The tip portions of the pair of rod-shaped members are inserted from the outside between each of the action point projections and the split formwork main body, and displaced in the rotational direction to form the joint by the principle of leverage. 4. The method of pulling out a joint forming plate member using a rod-shaped member according to claim 3, wherein the plate member for joint formation is displaced toward the inner side of the main body of the split formwork. 5. A pull-out jig used in the pull-out method of the joint forming plate members using the rod-shaped members according to claim 3 or 4, wherein the pair of rod-shaped members are separated by a distance that allows the joint portion-forming plate members to be inserted. A pull-out jig that is arranged in parallel while maintaining its width and that is integrally fixed by connecting one end thereof via a plate member.

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