JP7198656B2 - Formwork support members and formwork support structures - Google Patents

Description

The present invention relates to a formwork support member and a formwork support structure for supporting a formwork installed on the inner peripheral surface of a tunnel.

In tunnel construction, when constructing a concrete side wall for supporting a precast floor slab as shown in Patent Document 1, a formwork is installed on the inner peripheral surface of the tunnel. This type of formwork method includes, for example, a method in which the lower part of a self-supporting formwork is fixed with fixing metal fittings, and lateral pressure during concrete placement is transmitted to the tunnel frame via a separator (self-supporting formwork method); There is a method using a formwork (movable formwork method), and a method of fixing a precast formwork with an open upper end to the inner part of the segment as shown in Patent Document 1 (precast formwork method). rice field. A precast formwork is composed of a frame and barrier plates attached to the sides of the frame (see FIG. 3 of Patent Document 1).

JP 2006-152746 A

In the self-standing formwork method, mobile formwork method, and precast formwork method described above, the lower end of the formwork (dam plate) is abutted against the inner peripheral surface of the tunnel, so the lower end of the concrete placing space The part has an acute angle, making it difficult for the aggregate to enter. In addition, since the formwork and the inner peripheral surface of the tunnel are in line contact, there is a risk of creating a gap. If there is a gap between the inner peripheral surface of the tunnel and the formwork, there is a problem that slag leaks from the gap and the like, and junkers are likely to occur during concrete placement. In addition, in the self-supporting formwork method, there is also the problem that the finished shape of the side wall is affected by the installation position accuracy of the fixing metal fittings.

From this point of view, it is an object of the present invention to provide a formwork support member and a formwork support structure that can improve the quality and finished form accuracy of concrete members constructed in a tunnel.

A first invention for solving such problems is a formwork support member that supports a formwork installed on the inner peripheral surface of a tunnel. The formwork support member includes a support body extending along the axial direction of the tunnel, and the support body has a contact surface in contact with the inner peripheral surface of the tunnel, and the formwork is placed thereon. A mounting surface is provided , a notch is formed in the contact surface, and a backup material made of an elastic member is attached to the notch .

According to the formwork support member having the above configuration, since the lower end of the formwork can be brought into contact with the placement surface, concrete is less likely to leak. Also, by providing the mounting surface, the lower end of the concrete placing space (the inner peripheral surface of the tunnel, the mounting surface, and the space surrounded by the formwork) can be widened, making it easier for the aggregates to enter. As described above, according to the present invention, it is possible to prevent the occurrence of slag leakage and suppress the occurrence of junkers, so that the quality of concrete members can be improved. In addition, by marking the mounting surface and setting the formwork, it is possible to improve the accuracy of the installation position of the formwork, and thus to improve the accuracy of the finished shape of the concrete member.

The formwork support member further includes a connecting member that engages another adjacent formwork support member. , the one in which the connecting member is inserted is preferable. According to such a configuration, the adjacent supporting body bodies can be coaxially connected, so that the contact surfaces are reliably brought into contact with the inner peripheral surface of the tunnel.

A second invention for solving the above problems is a formwork support structure for supporting formwork installed on the inner peripheral surface of a tunnel. The formwork support structure includes a support member extending along the axial direction of the tunnel and a fixing member fixing the support member. The support member includes a contact surface that contacts the inner peripheral surface of the tunnel and a mounting surface on which the formwork is placed, and the fixing member is fixed to the inner peripheral surface of the tunnel obliquely above the support member. and is adjustable in length.

According to the formwork support structure having such a configuration, since the lower end of the formwork can be brought into contact with the mounting surface, concrete is less likely to leak. Moreover, since the lower end of the concrete placing space can be widened by providing the mounting surface, the aggregate can easily enter. As described above, according to the present invention, it is possible to prevent the occurrence of slag leakage and suppress the occurrence of junkers, so that the quality of concrete members can be improved. In addition, by marking the mounting surface and setting the formwork, the positional accuracy of the formwork can be increased, and the accuracy of the side wall can be improved. Furthermore, by adjusting the length of the fixing member, the installation position of the support member can be adjusted, so that the accuracy of the finished shape of the concrete member can be further improved.

According to the formwork support member and the formwork support structure according to the present invention, it is possible to improve the quality and finished form accuracy of the concrete members constructed in the tunnel.

FIG. 2 is a cross-sectional view showing a tunnel with constructed sidewalls; 1 is a front view showing a state in which a formwork is installed on a formwork support structure and a formwork support member according to an embodiment of the present invention; FIG. It is the side view which showed the formwork support structure and the formwork support member which concern on embodiment of this invention. 1 is an exploded perspective view showing a formwork support structure according to an embodiment of the present invention; FIG.

A form support member and a form support structure according to embodiments of the present invention will be described with reference to the attached drawings. In this embodiment, as shown in FIG. 1, the case of constructing the side walls 3 for supporting the precast floor slabs 2 using the formwork 4 (see FIG. 2) is exemplified. Such a form support member and a form support structure are for supporting the form 4 installed on the inner peripheral surface of the tunnel 1, as shown in FIG. The formwork 4 is erected vertically and extends along the axial direction of the tunnel 1 . As shown in FIGS. 2 and 3 , the formwork support structure 10 includes support members (formwork support members) 11 and fixing members 31 .

The support member 11 is a member that supports the formwork 4 and includes a support body 12 extending along the axial direction of the tunnel 1 and a connecting member 21 . The supporting portion main body 12 is a precast rod-shaped member formed by vacuum extrusion molding as a factory product, using cement, silica powder, water, wollastonite, mecerose, and polypropylene reinforcing fibers as raw materials. The support body 12 is made of a fiber-reinforced cement material having excellent compressive strength and durability, and is also a residual form that is left after the side walls 3 are concreted. The material and manufacturing method of the support body 12 are not limited to those described above. For example, the support body 12 can be manufactured using a formwork method using high-strength fiber-reinforced concrete (such as ductal) or resin (resin-based) concrete. Furthermore, the support main body 12 may be manufactured by a formwork method, usually using concrete as a material (in this case, the cross section may be enlarged for reasons such as strength and manufacturing).

The support member 11 has a substantially pentagonal cross section and includes a contact surface 13, a mounting surface 14, a vertical surface 15, and a pair of orthogonal surfaces 16,16. The contact surface 13 is a surface in contact with the inner peripheral surface 5 of the tunnel 1 and is formed in a planar shape substantially along the inner peripheral surface 5 . The contact surface 13 is inclined with respect to the mounting surface 14 . The inclination angle of the contact surface 13 with respect to the mounting surface 14 is set according to the inclination of the position of the inner peripheral surface 5 where the support member 11 is installed. In addition, the contact surface 13 may be arc-shaped along the inner peripheral surface 5 .

The mounting surface 14 is a horizontal surface on which the mold 4 is mounted. The mounting surface 14 is in surface contact with the lower end surface of the formwork 4 . The mounting surface 14 is formed on the upper end surface of the support member 11 . The vertical surface 15 is formed on the tip side of the mounting surface 14 (on the inner side of the tunnel) and constitutes the side surface of the support member 11 . The orthogonal surfaces 16 are orthogonal to the contact surface 13 and rise from both ends of the contact surface 13 in the width direction. The orthogonal surface 16 rises at right angles to the inner peripheral surface 5 . A notch portion 17 is formed in a continuous portion between the orthogonal surface 16 located on the upper side and the contact surface 13 . A backup material 18 made of an elastic member is attached to the notch 17 . The backup material 18 is a rod-like (string-like) material made of foamed resin or the like. The backup material 18 is attached to the cutout portion 17 in a compressed state, and has a function of preventing slag.

As shown in FIGS. 2 and 4, the support body 12 has a tubular shape with a hollow portion 20 . The hollow portion 20 has a circular cross section and is formed over the entire length of the support portion main body 12 . An end portion of the hollow portion 20 serves as an insertion portion 22 (see FIG. 4) into which the connecting member 21 is inserted.

The connecting member 21 is a rod-shaped member that connects the adjacent supporting portion main bodies 12, 12, and is bridged and fitted to the adjacent hollow portions 20, 20. As shown in FIG. The connecting member 21 is composed of a rust-proof single pipe such as a carbon steel pipe or a stainless steel pipe. The end faces of the adjacent supporting body bodies 12, 12 are in contact with each other. By providing the connecting member 21 with antirust performance, it is possible to prevent rusting even when the joints of the support main bodies 12, 12 are opened due to a curve, construction error, or the like. In addition, since the connecting member 21 is composed of a single pipe, it is easily available and economical, and has a simple structure, so that construction costs can be reduced.

As shown in FIG. 3, there are two types of the support body 12: a long support body 12a and a short support body 12b. The long support body 12 a has a length dimension slightly smaller than the width dimension of the segment 6 and is arranged in the central portion of the segment 6 . For example, when the width dimension of the segment 6 is 1600 mm, the long support body 12a has a length dimension of 1400 mm with both ends shortened by 100 mm. The short support body 12b is a member that is arranged across the connecting portion of the segments 6, and has a length dimension obtained by subtracting the length dimension of the long support body 12a from the width dimension of the segment 6 (this embodiment 200 mm). When the tunnel 1 curves, the overall length of the support body 12 can be adjusted by changing the length of the short support body 12b.

As shown in FIG. 2 , the fixing member 31 is a member that fixes the support member 11 to the inner peripheral surface 5 of the tunnel 1 . The fixing member 31 of this embodiment fixes the elongated support body 12a. A plurality of fixing members 31 are provided at predetermined intervals in the axial direction of the tunnel 1 . The fixing member 31 includes a fixing portion 33 and a suspending member portion 34 . The fixed portion 33 is a portion that is fixed to the inner peripheral surface 5 obliquely above the support member 11 . The fixed portion 33 is composed of an insert 35 attached to the inner peripheral surface 5 and an angle member 36 fixed to the insert 35 . The angle member 36 has an L-shaped cross section and includes a bottom plate portion 36a in contact with the inner peripheral surface 5 and a rising plate portion 36b rising from the bottom plate portion 36a. The insert 35 is inserted through the bottom plate portion 36a. The hanging member portion 34 is inserted through the rising plate portion 36b. The angle member 36 is provided with a reinforcing rib 37 spanning the bottom plate portion 36a and the rising plate portion 36b.

The suspending member 34 is a portion for suspending and fixing the support member 11 to the fixed portion 33 , and extends obliquely downward from the fixed portion 33 along the radial direction of the tunnel 1 . The hanging member 34 includes a full thread bolt 38 , a high nut 39 and a long bolt 40 . The fully threaded bolt 38 is arranged above the high nut 39 and fixed to the fixed portion 33 . An end portion of the fully threaded bolt 38 is inserted through the rising plate portion 36b and fixed to the rising plate portion 36b via a nut N and a washer W. As shown in FIG.

The high nut 39 is a part for adjusting the installation position (height) of the support member 11 . A high nut 39 is screwed onto the lower end of the fully threaded bolt 38 . The upper end of the long bolt 40 is screwed into the lower end of the high nut 39 . By rotating the long bolt 40, the long bolt 40 is moved with respect to the high nut 39, and the height position of the long bolt 40 is adjusted.

The long bolt 40 is inserted through the support member 11 from the lower orthogonal surface 16 of the support member 11 , passes through the hollow portion 20 , and protrudes from the upper orthogonal surface 16 . The long bolt 40 is fixed to the support member 11 via a nut N and a washer W. The tip of the long bolt 40 projecting upward is screwed into the high nut 39 . The long bolt 40 and the nut N and washer W exposed to the outside after placing the concrete are hot-dip galvanized. In addition, the antirust processing of the nut N and the washer W is not limited to hot-dip galvanizing. For example, the nut N and washer W may be coated with an antirust coating, or a stainless steel nut and washer may be used. The fixing member 31 positioned at the end of the support member 11 is positioned close to the end so as not to interfere with the connecting member 21 . That is, when the connecting member 21 is inserted into the insertion portion 22 of the hollow portion 20, the tip of the connecting member 21 abuts the long bolt 40, and the insertion positioning of the connecting member 21 is achieved.

When the formwork 4 is installed on the formwork support structure 10 configured as described above, the mounting surface 14 of the support member (formwork support member) 11 is marked and the formwork 4 is placed. The formwork 4 is placed on the mounting surface 14 so that the surface on which it is placed is located in the middle portion of the mounting surface 14 in the width direction. The formwork 4 is fixed by a spacer 51 welded to a reinforcing frame provided in the concrete placing space. After concrete placing and curing, the formwork 4 is removed, and the supporting member 11 and the fixing member 31 are left as part of the side wall 3 .

According to the formwork support structure 10 and the formwork support member 11 according to the present embodiment, since the lower end of the formwork 4 can be brought into surface contact with the mounting surface 14, concrete is less likely to leak. In addition, since the horizontal placing surface 14 is provided, the lower end of the concrete placing space can be widened, so that the aggregate can be filled up to the lower end of the placing space without gaps. In addition, since the form support member 11 is in surface contact with the inner peripheral surface 5 of the tunnel 1 via the contact surface 13, a gap is less likely to occur between the inner peripheral surface 5 and the form support member 11. . Therefore, slag leakage from the form support member 11 is less likely to occur. Furthermore, since the backup material 18 is attached to the continuous portion between the orthogonal surface 16 and the contact surface 13, leakage of slag from between the inner peripheral surface 5 and the form support member 11 is further suppressed. Therefore, it is possible to suppress the occurrence of junkers in the concrete of the side wall 3, so that the quality of the concrete member (side wall 3) constructed inside the tunnel 1 can be improved.

In addition, by setting the formwork 4 by marking the mounting surface 14, the accuracy of the installation position of the formwork 4 can be improved. As a result, the precision of the finished shape of the concrete member (side wall 3) can be improved.

In the present embodiment, the support main body 12 has a hollow portion 20, and by inserting a connecting member 21 into the adjacent hollow portions 20, the adjacent support portion main bodies 12, 12 can be coaxially connected. . This ensures that the contact surface 13 of the support member 11 comes into contact with the inner peripheral surface of the tunnel. Furthermore, since the support body 12 is lightweight, it has good handling performance and is easy to construct.

Furthermore, since the installation position (height) of the support member 11 can be adjusted by adjusting the length of the fixing member 31, the installation position accuracy of the support member 11 and the formwork 4 can be further increased. This makes it possible to further improve the precision of the shape of the side wall.

Although the embodiments for carrying out the present invention have been described above, the present invention is not intended to be limited to the above-described embodiments, and design changes can be made as appropriate without departing from the spirit of the present invention. For example, in the above-described embodiment, the long bolt 40 is made of one member, is inserted from the lower orthogonal surface 16 of the support member 11, passes through the hollow portion 20, and protrudes from the upper orthogonal surface 16. However, it is not limited to this. The long bolt 40 may be divided in the longitudinal direction into two members, which may be connected in the hollow portion 20 via nuts. According to such a configuration, since the long bolt 40, the nut N and the washer W protruding to the outside of the support member 11 can be removed together with the removal of the formwork 4, the usability of the support member 11 is improved.

Further, in the above-described embodiment, the case of supporting the formwork 4 for constructing the side wall 3 that supports the precast floor slab 2 inside the tunnel 1 was exemplified. The forms supported by the frame support members 11 are not limited to those for the side walls 3 . The formwork support structure 10 and the formwork support member 11 can support other formwork as long as the formwork is formed along the inner peripheral surface 5 .

1 tunnel 3 side wall (concrete member)
4 formwork 5 inner peripheral surface 10 formwork support structure 11 support member (formwork support member)
REFERENCE SIGNS LIST 12 support portion main body 13 contact surface 14 mounting surface 20 hollow portion 21 connecting member 22 insertion portion 31 fixing member

Claims (3)

A form support member for supporting a form installed on the inner peripheral surface of a tunnel,
a support body extending along the axial direction of the tunnel;
The support body includes a contact surface that contacts the inner peripheral surface of the tunnel and a mounting surface on which the formwork is mounted,
A notch is formed in the contact surface, and a backup material made of an elastic member is attached to the notch.
A form support member characterized by: A form support member for supporting a form installed on the inner peripheral surface of a tunnel,
A support body extending along the axial direction of the tunnel and a connecting member engaging another adjacent formwork support member,
The support body has a cylindrical shape with a hollow portion, and has a contact surface that contacts the inner peripheral surface of the tunnel and a mounting surface on which the formwork is mounted,
A form support member, wherein the connection member is inserted into an end portion of the hollow portion. A formwork support structure for supporting formwork installed on the inner peripheral surface of a tunnel,
a support member extending along the axial direction of the tunnel; and a fixing member fixing the support member,
The support member has a contact surface in contact with the inner peripheral surface of the tunnel and a mounting surface on which the formwork is mounted,
The formwork support structure, wherein the fixed member is fixed to the inner peripheral surface of the tunnel obliquely above the support member and is adjustable in length.

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