JP6357960B2 - Repair and reinforcement methods for existing tunnels - Google Patents

Description

  The present invention relates to an existing tunnel repair / reinforcement method for reinforcing an existing tunnel using a formwork.

  Existing tunnel lining concrete is subject to various effects such as earth pressure and other external forces and usage environment, and is prone to deformation such as floating, peeling or peeling. As a method for repairing / reinforcing existing tunnels in which deformation has occurred in the lining concrete, for example, Patent Document 1 discloses an embedded formwork using an embedded formwork.

  The method described in Patent Document 1 divides an embedded formwork manufactured by a factory that is curved in accordance with the curved surface of the existing lining concrete into a plurality of precast formwork, and the divided precast formwork is divided into the existing lining concrete. Is installed with a certain gap between them, and a grout material is filled between the precast formwork and the existing lining concrete.

JP 2002-213194 A

However, the method described in Patent Document 1 has the following problems.
(1) Since a general-purpose formwork cannot be applied to an embedded formwork, an embedded formwork that matches the curved surface of the existing lining concrete must be individually produced for each existing tunnel to be repaired or reinforced. In addition, the production is complicated and the cost is enormous.
(2) In order to maintain the shape as a mold material, the divided precast molds need to increase the bending rigidity by increasing the thickness of the member, and the weight tends to increase even if divided into small parts. Thereby, since a large-scale work facility such as a lifting machine is required at the time of construction, it is necessary to use a protector that protects the in-service portion when the construction is performed in service in the tunnel, resulting in poor work efficiency.
(3) Since the divided precast formwork is a structure in which each is independently fixed to the existing lining concrete, a plurality of anchor bolts are arranged along the outer periphery of the precast formwork, and the precast formwork is It must be fixed to the existing lining concrete, the number of members is greatly increased, and the work of attaching the precast formwork becomes complicated.

  The present invention has been made in view of such a problem, and its main purpose is good workability, and it is not necessary to individually produce a formwork according to the curved surface of the lining concrete to be repaired or reinforced. It is to provide a method for repairing and reinforcing existing tunnels using formwork.

  In order to achieve this object, the method for repairing / reinforcing an existing tunnel according to the present invention includes a plurality of rod-like support members, one end of which is fixed to existing lining concrete, spaced in the axial direction of the existing tunnel to be repaired or reinforced. Installed, constructed only one row of rod-shaped support members, and placed a flat strip-shaped form plate material so that the longitudinal direction is parallel to the tunnel axis with a space between the existing lining concrete Then, after fixing the center point in the short direction to the other end of the rod-shaped support member at least twice or more upwards from the lower end of the side wall part to form an assembled wall formwork of a specified height, In the repairing / reinforcing method for an existing tunnel, a step of filling and hardening a cement-based hardener between the assembled wall formwork and the existing lining concrete is repeated from the lower end of the side wall toward the crown. An existing cover, wherein the frame has a polygonal cross-sectional shape formed by connecting and integrating the upper end portion of the mold plate material fixed in advance and the lower end portion of the mold plate material fixed in succession. It is formed in a pseudo curved surface that follows the curved surface of the engineered concrete.

  According to the above-described existing tunnel repair / reinforcement method, a plurality of flat-plate-shaped formwork plate materials are connected and integrated to construct a assembled wall formwork having a polygonal cross section, and the assembled wall formwork is used as the existing lining concrete. Because it is formed in a pseudo curved surface that follows the curved surface of the above, it is not necessary to individually manufacture the assembled wall formwork according to the existing tunnel, and the formwork board that is generally used as the formwork plate material can be used Thus, it is possible to save labor for manufacturing the assembled wall formwork and to greatly reduce the cost.

  In addition, since it is possible to construct a wall-form formwork by simply connecting and integrating a plurality of flat strip-shaped formwork plate materials at the site, even if the deformation of the existing tunnel is different as it progresses in the axial direction, Depending on the degree of deformation, the distance between the assembled wall formwork and the existing lining concrete can be changed to appropriately adjust the cross-sectional thickness of the cementitious hardener.

  Furthermore, when the rod-shaped support member is attached to a central point in the short direction, the lateral pressure due to the filling of the cement-based hardener acts almost uniformly on the mold plate material in the vertical direction with the rod-shaped support member as a fulcrum. The plate thickness of the plate material can be made uniform and small.

And since the upper end part and lower end part of a formwork plate material are connected and integrated with the adjacent formwork plate material, the entire plurality of formwork plate materials connected and integrated with respect to the side pressure due to the filling of the cement-based hardener Resist at. Further, as described above, when the rod-like support member is attached to a single point in the central portion in the short direction, the lateral pressure due to the filling of the cement-based hardener is applied to the upper and lower mold plate materials with the rod-like support member as a fulcrum. .
These upper and lower ends are connected and integrated with the adjacent mold plate material, and combined with the action of the support structure of the mold plate material, such as attaching one central point in the short direction to the rod-like support member, each mold plate material is in the out-of-plane direction. Since the deformation of the sheet is suppressed, the thickness of the member can be reduced compared to the case where each of the form plate materials is independently fixed to the lining concrete, so that the weight can be reduced and the weight can be reduced. Become.

  In addition, the mold plate material is supported by the covering concrete at one central portion in the short direction, and the upper end and the lower end are connected and integrated with the adjacent mold plate material. It is not necessary to support the periphery of each frame plate material on the lining concrete with a rod-shaped support member. Thereby, even if the length in the short direction of the formwork plate material is shortened, the rod-like support members are not excessively densely arranged, so that the length in the short direction can be freely changed.

  In the method for repairing / reinforcing an existing tunnel according to the present invention, a band-shaped backing material is disposed on the side of the cemented hardened material in the form plate material so as to straddle between adjacent form plate materials. The form plate members adjacent to each other are connected and integrated.

According to the above existing tunnel repair / reinforcement method, since the strip-shaped backing material is arranged so as to straddle between adjacent mold plate materials, even if the mold plate materials are connected and integrated with each other with an opening angle θ. It becomes possible to greatly improve the water stop function of the connecting portion.
In addition, since the adjacent mold plate materials are connected via a belt-like backing material, it is possible to improve the rigidity in the out-of-plane direction of the connecting portion between the adjacent mold plate materials.

  The method for repairing / reinforcing an existing tunnel according to the present invention is characterized in that a high-toughness cement board having cement as a main component and high-strength vinylon fiber as a reinforcing fiber is used as the mold plate material.

According to the above existing tunnel repair / reinforcement method, since a high-toughness cement board containing reinforcing fibers is used for the formwork plate material, compared with the conventional buried formwork based on mortar. Since the member thickness can be reduced in the strong formwork, the weight is reduced, and the weight can be reduced to such an extent that the work can be performed without using a lifting machine.
Along with this, when carrying out repair and reinforcement methods for existing tunnels, work can be done on a framed scaffold that can be easily assembled and disassembled to save space, greatly reducing the work space. In addition, it is possible to perform work while using a live road in the tunnel without using a protector.

  According to the present invention, a plurality of flat plate-like formwork plate materials are connected and integrated to construct a assembled wall formwork having a polygonal cross-sectional shape, and this assembled wall formwork is simulated in accordance with the curved surface of the existing lining concrete. Since it is formed into a curved surface, it is not necessary to individually manufacture the formwork according to the curved surface of the existing lining concrete, and it is possible to repair and reinforce the existing tunnel with a simple structure and good workability. .

It is a figure which shows the cross section of the existing tunnel repaired and reinforced using the assembled wall formwork. It is a figure which shows the outline of a braided wall formwork. It is a figure which shows the formwork board | plate material which comprises an assembled wall formwork. It is a figure which shows the joint structure at the time of fixing a formwork board | plate material to existing lining concrete. It is a figure which shows the repair and reinforcement method (the 1) of the existing tunnel. It is a figure which shows the repair and reinforcement method of the existing tunnel (the 2). It is a figure which shows the repair and reinforcement method (the 3) of an existing tunnel.

  Below, the repair / reinforcement method of the existing tunnel will be described with reference to FIGS.

As shown in the cross-sectional view of the existing tunnel in FIG. 1, the repairing / reinforcing method for the existing tunnel of the present invention is that the lining surface 1 of the lining concrete 1 in the existing tunnel is attached to the assembled wall form 2 as an embedded form. It is a method of repairing and reinforcing by using.
That is, as shown in FIG. 2, one end of the bar-shaped support member 6 is embedded and fixed to the existing lining concrete 1 with respect to the existing lining concrete 1, and the other end of the bar-shaped support member 6 is placed on the lining surface side. , And the assembled wall formwork 2 is arranged at a distance from the existing lining concrete 1 and fixed to the other end of the rod-like support member 6, and then the assembled wall formwork 2 and the existing covering A cement-type hardener 14 is filled between the concrete 1 and hardened.

  Further, in the repair / reinforcement method of the existing tunnel of the present invention, the assembled wall formwork 2 is not individually manufactured at the factory in accordance with the curved surface of the existing lining concrete 1, but as shown in FIG. The assembled wall mold 2 is constructed by connecting and integrating the flat plate-like formwork plate materials 3 which are frames in the field.

  Specifically, as shown in FIG. 4B, a plurality of flat plate-like formwork plate materials 3 arranged so that the longitudinal direction is parallel to the tunnel axis direction are connected in the short direction as shown in FIG. Then, by covering the lining surface of the existing lining concrete 1, the assembled wall form 2 having a polygonal cross section is formed. At this time, the quantity and position of the folding points are adjusted by adjusting the length in the short direction of the formwork plate material 3 in advance, and the assembled wall formwork 2 is simulated in accordance with the curved surface of the existing lining concrete 1. It is formed on a curved surface.

As shown in FIG. 3 (a), the mold plate material 3 used in the present invention is a plate material that has a flat strip shape and has high toughness and is used as an embedded mold material, such as cement board, FRP plate, steel plate, etc. Any plate material may be used.
In the present embodiment, a smooth board (registered trademark) having high density, deformation performance and bending strength is used as the formwork plate material 3. The smooth board is a plate material with cement as the main component and high-strength vinylon fiber as the reinforcing fiber. Since it is lightweight and has high toughness, it is easy to handle in the field, so it is widely used as an embedded formwork material. It is what.

  The form plate 3 is arranged along the tunnel axis along the longitudinal direction and the cross-sectional shape of the existing lining concrete along the short direction. In addition, the length of the longitudinal direction of the formwork board | plate material 3 is not limited at all, What is necessary is just to adjust suitably in consideration of conveyance conditions, workability, etc.

As shown in FIG. 3 (a), a backing material 4 in which a flat plate is formed in an L shape is arranged on either one of the side end portions and the upper end portion of the formwork plate material 3.
The backing material 4 is a member for connecting and integrating adjacent mold plate materials 3, and as shown in FIG. 3 (b), the mold plate material can be disposed across the adjacent mold plate materials 3. In a state of protruding from 3, it is bonded and fixed to the casting surface side of the cement-based hardener 14 in the mold plate material 3.

That is, when another mold plate material 3 is arranged above the short direction in the mold plate material 3, as shown in FIG. 3B, it is provided at the upper end portion of the mold plate material 3 located below the short direction. The protruding portion of the backing material 4 comes into contact with the vicinity of the lower end portion of the placing surface of the cement-based hardener 14 in the mold plate material 3 positioned above. Therefore, water-stopping performance is provided between the backing material 4 and the upper formwork plate 3 and between the upper end of the lower formwork plate 3 and the lower end of the upper formwork plate 3. By applying the adhesive 5 which has, the form-plate board | plate material 3 adjacent to a transversal direction is connected and integrated with a water stop function.
Although not shown, in addition to the adhesive 5, the backing material 4 and the mold plate material 3 positioned above may be fixed with screws.

  In this way, since the upper and lower ends of the mold plate material 3 are connected and integrated with the adjacent mold plate material 3, each of the mold plate materials 3 resists the side pressure caused by the filling of the cement-based hardener 14. Instead, it is possible to resist the entire plurality of formwork plate members 3 that are connected and integrated.

By the way, the connection structure of the form plate materials 3 adjacent to each other above and below in the short direction can freely adjust the connection angle of the adjacent form plate materials 3.
That is, when it is desired to connect the form plate members 3 adjacent in the short direction with the opening angle θ, as shown in FIG. The lower end portion of the frame plate material 3 is brought into contact with the opening angle θ. In this state, the gap formed between the upper end portion of the lower formwork plate material 3 and the lower end portion of the upper formwork plate material 3, and the backing material 4 provided on the lower formwork plate material 3 and the upper side What is necessary is just to fill with the adhesive agent 5 the space | gap produced between the formwork board materials 3 located in this.

  In addition, the board | plate material used for the backing material 4 is not specifically limited, Any board | plate material may be employ | adopted, but in this Embodiment, the backing material 4 is a board | plate material of the same material as the formwork board | plate material 3, for example. Molded with As for the adhesive 5, any material such as a silicon-based adhesive or a curable resin-based adhesive may be adopted as long as it has a water stop function.

As described above, when the flat backing material 4 is arranged so as to straddle between the adjacent mold plate materials 3, the connection portion between the adjacent mold plate materials 3 not only significantly improves the water stoppage. Further, the rigidity in the out-of-plane direction is also improved.
In addition, the connection structure of the mold plate materials 3 adjacent to each other in the longitudinal direction of the tunnel axis is the same as the connection structure of the mold plate materials 3 adjacent above and below.

  When a plurality of formwork plate materials 3 are connected in the short direction through the backing material 4 in this way, as shown in FIG. 2, the assembled wall formwork 2 having a polygonal cross section is formed into the existing lining concrete 1. Are formed at intervals on the lining surface side. Even if the short direction is not curved in this way, by connecting and integrating the linear form plate material 3 in the short direction while adjusting the opening angle θ, as shown in FIG. It becomes possible to form the assembled wall form 2 having a pseudo curved surface that follows the curved surface of the engineered concrete 1.

  Therefore, it is not necessary to individually manufacture the mold plate material 3 in the factory in accordance with the existing tunnel, and a cement board that is generally used for the mold plate material 3 can be used. This saves time and greatly reduces costs.

  The assembled wall formwork 2 whose cross-sectional shape forms a polygonal line shape is not individually manufactured according to the curved surface of the existing lining concrete 1, so the length in the short direction of the formwork plate material 3 is appropriately changed, By adjusting the number of break points and the position of the break points, it is also possible to change the size of the inner cross section of the assembled wall mold 2 and adjust the smoothness of the cross section.

  In other words, when it is desired to increase the inner cross section of the assembled wall mold 2 and to improve the aesthetic appearance by making the sectional shape of the assembled wall mold 2 smoother, the length in the short direction of the mold plate 3 may be shortened. . Thereby, since the quantity of the formwork board | plate material 3 required increases, the quantity of a break point will increase, but it will approach the curved shape according to the curved surface of the lining concrete 1. FIG.

  Further, the size of the assembled wall mold 2 itself can be freely changed by appropriately adjusting the length in the short direction and the quantity of the mold plate material 3. For this reason, for example, even when the deformation of the existing tunnel varies as it advances in the tunnel axis direction, the distance between the assembled wall formwork 2 and the existing lining concrete 1 is easily changed according to the degree of deformation. It is possible.

  As shown in FIG. 3 (a), the mold plate member 3 having the above-described configuration includes a plurality of through-holes 3a arranged at intervals in the longitudinal direction with respect to a central point in the short direction. Are arranged in a row. The through-hole 3a is a hole through which the rod-like support member 6 used when fixing the form plate 3 to the existing lining concrete 1 is drilled in accordance with the installation interval of the rod-like support member 6 at the site. It is.

  As shown in FIG. 4 (a), the rod-like support member 6 used when fixing the formwork plate material 3 to the lining concrete 1 includes an anchor body 7 made of all screw bolts and a rear end of the anchor body 7. A long nut 8 with a seat that is screwed and a foam tie (registered trademark) 9 that is coaxially connected to the anchor main body 7 via the long nut 8 with a seat are provided.

The anchor main body 7 is a so-called post-installed anchor that drills a predetermined position of the existing lining concrete 1 and fills it with a resin-based adhesive and is fixed by being inserted into this hole to form an adhesive anchor. is there.
The seated long nut 8 is provided with a seat 8 'at the rear end of the long nut. As shown in FIG. 4 (a), the anchor main body from the tip of the long nut to the intermediate depth in the seated long nut 8 is provided. The rear end of 7 is screwed. On the other hand, the foam tie 9 is screwed from the rear end of the long nut in the seated long nut 8 to the intermediate depth.
The foam tie 9 is composed of all screw bolts similar to the anchor main body 7 and is a member used when the mold plate 3 is brought into contact with and fixed to the seat 8 ′ of the long nut 8 with a seat. And after the cement-type hardening material 14 with which it fills between the formwork board | plate material 3 and the existing lining concrete 1 hardens | cures, it is removed.

  As shown in FIG. 4 (b), a plurality of rod-like support members 6 having the above-described configuration are fixed to the existing lining concrete 1 at intervals in the tunnel axis direction, and are formed of the rod-like support members 6. Is building. Accordingly, the plurality of rod-like support members 6 arranged in a row in the tunnel axis direction are inserted into the plurality of through holes 3a arranged in the longitudinal direction of the above-described mold plate material 3 so that the mold plate material 3 becomes a rod-like support member. 6 is supported and fixed to the existing lining concrete 1.

Note that, as shown in FIG. 4A, the rod-shaped support member 6 and the mold plate material 3 are joined by inserting the foam tie 9 of the rod-shaped support member 6 into the through hole 3 a of the mold plate material 3. The cement-based hardened material 14 is placed in contact with the seat 8 'of the long nut 8 with a seat, and the seal 10 and the disk-shaped support 11 are inserted into the foam tie 9 and screwed into the foam tie 9. The structure is tightened with a nut 12.
The seal 10 allows the cement-based hardener 14 to leak out from the through holes 3a of the mold-plate member 3 when the cement-based hardener 14 is filled between the mold plate member 3 and the existing lining concrete 1. It is a member used to prevent

Thus, in this embodiment, since the seated long nut 8 is used, the positioning of the formwork plate material 3 with respect to the rod-shaped support member 6 is facilitated by bringing the seat 8 ′ into contact with the formwork plate material 3. ing. The seat 8 ′ of the seated long nut 8 is positioned relative to the rod-like support member 6 by adjusting the insertion length when the rear end of the anchor body 7 is screwed into the seated long nut 8 from the tip of the long nut. Do it.
Moreover, in this Embodiment, as shown in FIG.4 (b), the steel end thickness 13 is arrange | positioned on the upper surface of the support work 11 so that the support work 11 adjacent to a tunnel axial direction may be connected, and a steel end A configuration is adopted in which the nut 12 is screwed and tightened through the thick portion 13. Thereby, the support pressure by the support work 11 acts equally with respect to the longitudinal direction of the formwork board material 3.

  Furthermore, in the present embodiment, since the shape of the support 11 is formed in a disk shape that can come into contact with the formwork plate material 3 on a wide surface, the formwork plate material that receives a lateral pressure by the cement-based hardener 14. 3 can be efficiently supported by the support work 11.

  With the configuration described above, a plurality of formwork plate members 3 forming the assembled wall formwork 2 are formed on the existing lining concrete 1 via the rod-like support members 6 in which the formwork plate materials 3 are arranged in a line in the tunnel axis direction. It will be fixed.

  Thus, since the formwork board material 3 is being fixed to the existing lining concrete 1 via the row of rod-shaped support members 6 in the longitudinal direction, the number of members when the formwork board material 3 is fixed to the lining concrete 1 There are few and workability is good. Further, even if the length of the form plate 3 is shortened, the rod-like support member 6 is excessively dense compared to the case where a plurality of points in the transverse direction are fixed by the rod-like support member 6. Therefore, it is possible to freely change the length in the short direction.

In addition, since one central portion in the short direction of the mold plate material 3 is supported by the support 11 attached to the rod-like support member 6, the lateral pressure due to the filling of the cement-based hardener 14 is reduced in the short direction of the mold plate material 3. Balances by acting almost evenly above and below.
Such an operation and the mold plate material 3 are connected and integrated with respect to the side pressure due to the filling of the cement-based hardener 14 by integrating the upper end portion and the lower end portion with the adjacent mold plate material 3. Combined with the action of resisting the entire plurality of mold plate members 3, each of the mold plate members 3 is suppressed from deformation in the out-of-plane direction. For this reason, since the form-plate board | plate material 3 can make member thickness small compared with the case where each is fixed to the lining concrete 1 independently, a weight becomes small. Furthermore, when a high-toughness cement board is used for the formwork plate material 3, the member thickness can be made smaller compared to the case of using a formwork board of the same strength made of another material, so that further weight reduction can be achieved. It becomes possible.

The procedure of the repair / reinforcement method for the existing tunnel using the above-described assembled wall mold 2 made of the plurality of mold plate members 3 and the rod-like support member 6 will be described with reference to FIGS.
In the present embodiment, a case where an existing tunnel in service in two lanes is repaired and reinforced will be described as an example. Further, as described above, a smooth board (registered trademark) using cement as a main component and high-strength vinylon fibers as reinforcing fibers is used for the formwork plate material 3.

  Prior to construction, the cross-sectional thickness of the cement-based hardener 14 required for repairing / reinforcing the existing lining concrete 1 (that is, the separation distance between the assembled wall formwork 2 and the existing lining concrete 1), the existing tunnel The formwork is designed in consideration of the construction limit of the building, and the pseudo-curved surface that follows the curved surface of the existing lining concrete 1 with the required separation distance from the existing lining concrete 1 for the assembled wall formwork 2 Are determined in advance, such as the size and quantity of the mold plate material 3 and the arrangement position and quantity of the rod-like support member 6.

First, as shown in FIG. 5 (a), a frame scaffolding 16 is installed with one lane out of two lanes being used as a live road, while the other lane is closed, and the frame scaffolding 16 is protected. The sheet 16c is attached and the work area 15 is secured. Then, only one row of a plurality of rod-like support members 6 is installed on the side wall of the existing lining concrete 1 facing the work area 15 along the tunnel axis direction. At this time, the attachment position of the long nut 8 with a seat to the anchor main body 7 of the rod-like support member 6 is adjusted, and the distance between the seat 8 ′ of the long nut 8 with a seat and the existing lining concrete 1 is set as a cement-based hardener. The cross-sectional thickness of 14 is the same.
In addition, it is good to clean and roughen the surface of the lining concrete 1 before fixing the rod-shaped support member 6. FIG.

Next, a plurality of through holes 3a are formed at one spot in the center of the form plate 3 at the site with the same arrangement interval as that of the plurality of rod-like support members 6 installed in the tunnel axis direction. . Then, the foam tie 9 of the rod-like support member 6 is inserted into the through-hole 3a, and the placing surface of the cement-based hardener 14 in the form plate 3 is brought into contact with the seat 8 ′ of the long nut 8 with a seat. Thereafter, as described above, the nut 12 is screwed into the foam tie 9 via the support 11 and the steel end 13 so that the lowermost bar-shaped support is provided as shown in FIG. The formwork plate material 3 is fastened and fixed to the member 6.
It should be noted that the above-described backing material 4 is fixed to the mold plate material 3 in advance.

  Thereafter, as shown in FIG. 5 (c), only one row of the plurality of rod-shaped support members 6 is newly constructed above the row of the plurality of rod-shaped support members 6 constructed in advance. After adjusting the attachment position of the long nut 8 with a seat to the anchor body 7 of the member 6, a new form plate material 3 is fixed to the rod-like support member 6.

  And as previously mentioned with reference to FIG.3 (b), the protrusion part of the lining material 4 provided in the upper end part of the formwork board | plate material 3 installed previously is in the formwork board | plate material 3 newly installed. It arrange | positions at the casting surface side of the cementitious hardening material 14, and both are fixed with the adhesive agent 5 and the bis | screw which is not illustrated. As a result, the form plate material 3 installed in advance and the form plate material 3 newly installed are connected and integrated.

The above steps are repeated until the height of the connected form plate members 3 reaches a specified height L as shown in FIG.
In the present embodiment, the connection work of the mold plate material 3 is performed at least twice before reaching the specified height L. That is, the length in the short direction of the mold plate material 3 is set so that at least two of the mold plate materials 3 are used until the specified height L is reached.
Further, the specified height L was set to 2 m so that the side pressure at the time of placing the cement-based hardening material 14 acting on the mold plate material 3 would not be excessive. The specified height L is not limited to 2 m, and may be set as appropriate according to the properties of the cement-based hardener 14 to be placed, the driving speed, and the like.

When the height of the connected mold plate material 3 reaches the specified height, as shown in FIG. 6B, a cement-based hardener 14 is filled between the mold plate material 3 and the existing lining concrete 1. . In the present embodiment, a non-shrink mortar having a strength higher than that of the young material age, which can secure a strength of 30 N / mm ² or more after curing for 3 days, is adopted as the cement-based hardener 14.

  While curing the cement-based hardened material 14 placed, as shown in FIG. 6 (c), while the lane that was closed to secure the work area 15 was released, it was used as a live road. The work area 15 is secured by blocking the lane that has been in service as a live road. And the construction similar to the above which concerns on the rod-shaped support member 6 and the formwork board material 3 is performed on the side wall in the existing lining concrete 1 which faces the work area 15, and the height of the connected formwork board material 3 is the prescribed height. When it reaches L, the cement-type hardener 14 is similarly filled between the mold plate material 3 and the existing lining concrete 1 and cured.

As shown in FIGS. 7 (a) and 7 (b), these operations are repeated from the side wall portion toward the crown portion while being alternately performed on one side and the other side wall portion.
Here, as shown in FIG. 7 (a), when a new formwork plate material 3 is installed above the formwork plate material 3 on which the cement-based hardener 14 is placed, it is placed first. The cement-based hardened material 14 has a desired strength, and in a state where the nut 12, the steel end 13, the support 11 and the foam tie 9 can be removed from the rod-like support member 6, The formwork plate material 3 is installed on the upper side until the specified height L is newly reached, and the cement-based hardener 14 is succeeded.

  Therefore, if the desired strength is expressed in the cement-based hardened material 14 previously placed, it is not always necessary to alternately and regularly construct one and the other of the side wall portions. For example, after the process of constructing the mold plate material 3 up to the specified height L on one side of the side wall and placing the cement-based hardened material 14 is repeated a plurality of times toward the crown, on the other side of the side wall Similarly, the process of constructing the mold plate 3 to the specified height L and placing the cement-based hardener 14 may be repeated a plurality of times toward the crown.

In addition, while carrying out the operation of removing the nut 12, the steel edge 13, the support 11 and the foam tie 9 in which the desired strength is developed in the cement-based hardened material 14, the work related to repair and reinforcement is performed. By proceeding, the nut 12, the steel end 13, the support 11 and the foam tie 9 can be diverted.
Further, when the foam tie 9 is removed from the seated long nut 8, a cap (not shown) is attached to the rear end side of the seated long nut 8 in which the foam tie 9 has been inserted, and the foam tie 9 is inserted. Close the hole.

Finally, as shown in FIG. 7 (c), the same construction as described above related to the rod-shaped support member 6 and the formwork plate material 3 is applied to the crown portion of the existing lining concrete 1, so that the existing lining The upper end portions of the mold plate material 3 rising from the both side walls of the tunnel 1 toward the crown portion are connected to each other, and a cement-based hardener is provided between the mold plate material 3 of the crown portion and the existing lining concrete 1. 14 is filled.
In addition, although not shown in the figure, the filling plate and the air vent hole for filling with the cement hardening material 14 are provided in the formwork plate material 3 of the crown portion.

As a result, the assembled wall mold 2 covering the lining surface of the lining concrete 2 is constructed, and the cement-based hardener 14 is filled between the assembled wall mold 2 and the existing lining concrete 1, Existing tunnels will be repaired and reinforced.
After curing, the nut 12, the steel end piece 13, the support 11 and the foam tie 9 are removed from all the rod-like support members 6, and a cap is attached to the rear end side of the seated long nut 8 to complete the operation.

  In the present embodiment, the length of the mold plate material 3 in the short direction is set to be short enough to use at least two of the mold plate materials 3 until the specified height L is reached. Smooth board (registered trademark) with high strength vinylon fiber as the main component is used, so the weight is small compared to conventional embedded formwork based on mortar, and there is no need to use a lifting machine The weight can be reduced to such an extent that work can be performed.

  In connection with this, as shown in FIGS. 5 to 7, when the repair / reinforcement method for the existing tunnel is carried out, the work is performed on the frame scaffold 16 that can be easily assembled and disassembled in the work space 15 and can save space. It can be performed. As a result, the work space 15 can be greatly reduced, and safety can be secured with the simple fall prevention plate 16a, fence 16b, and protective sheet 16c as shown in FIG. It is not necessary to use a protector that is generally used when performing construction while in service.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  In the present embodiment, the repair / reinforcement method for the existing tunnel is repaired / reinforced alternately on the left and right side walls of the existing lining concrete 1, but is not necessarily limited thereto. For example, after repairing / reinforcing one of the left and right side walls up to the crown part, the procedure may be similarly used for repairing / reinforcing the other side wall up to the crown part.

  Further, the procedure for repairing / reinforcing the existing tunnel in the axial direction by the repair / reinforcement method for the existing tunnel of the present invention is not particularly limited. For example, the tunnel axis direction may be divided into a plurality of sections, and repair / reinforcing work may be performed for each of the divided sections.

  According to the present invention, a plurality of flat plate-like formwork plate members 3 are connected and integrated to construct a assembled wall formwork 2 having a polygonal cross-sectional shape, and this assembled wall formwork 2 is used as a curved surface of the existing lining concrete 1. Therefore, it is not necessary to individually manufacture the formwork according to the curved surface of the existing lining concrete 1, and the existing tunnel is repaired and reinforced with a simple structure and good workability. It becomes possible.

DESCRIPTION OF SYMBOLS 1 Covering concrete 2 Embedded mold 3 Mold frame board material 3a Through-hole 4 Backing material 5 Adhesive 6 Bar-shaped support member 7 Anchor main body 8 Seated long nut 9 Form tie 10 Seal 11 Supporting work 12 Nut 13 Steel end 14 Cement Hardened material 15 work area 16 frame scaffold 16a fall prevention plate 16b fence 16c protective sheet

Claims (3)

In the axial direction of the existing tunnel to be repaired or reinforced, a plurality of rod-like support members, one end of which is fixed to the existing lining concrete, are installed at intervals, and only one row of rod-like support members is constructed. A flat strip-shaped formwork plate material is arranged so that the longitudinal direction thereof is parallel to the tunnel axis with a space between the lining concrete and a central point in the short direction at the other end of the rod-shaped support member. After the fixing process is repeated at least twice from the lower end of the side wall part to form the assembled wall formwork of the specified height, cement-based hardening between the assembled wall formwork and the existing lining concrete In the repair and reinforcement method for existing tunnels, the process of filling and hardening the material is repeated from the lower end of the side wall toward the crown.
The assembled wall formwork has a polygonal cross-sectional shape formed by connecting and integrating the upper end portion of the formwork plate material fixed in advance and the lower end portion of the formwork plate material fixed later. A method for repairing / reinforcing an existing tunnel, characterized in that it is formed on a pseudo curved surface following the curved surface of an existing lining concrete.   A strip-shaped backing material is disposed on the casting surface side of the cement-based hardener in the mold plate material so as to straddle between adjacent mold plate materials, and the adjacent mold frame materials are connected and integrated via the backing material. The method for repairing / reinforcing an existing tunnel according to claim 1, wherein:   The method for repairing / reinforcing an existing tunnel according to claim 1 or 2, wherein a high-toughness cement board having cement as a main component and high-strength vinylon fiber as a reinforcing fiber is used as the mold plate material.

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