JP4465459B2 - PC plate for lining and mounting structure of PC plate for lining - Google Patents

Description

The present invention relates to a repairing / reinforcing lining PC plate and a mounting structure for a lining PC plate to be installed on the inner surface of a tunnel when, for example, repairing or reinforcing an existing tunnel .

Conventionally, as a tunnel, for example, an arch-shaped tunnel is constructed with lining concrete while excavating a natural ground so as to support the load of the natural ground. As another tunnel, a natural mountain is excavated in the shape of a tunnel, and rock bolts are driven radially into the arch-shaped wall, and spray concrete is applied to this wall to support the load. There are known tunnels and the like in which the lining concrete of the line is constructed as decorative concrete.
These existing tunnels are damaged by rain, wind, water leakage, earth pressure, etc., and cracks and chips are generated over time, and the strength of the tunnel deteriorates. In this case, as a repair method, for example, as described in Patent Document 1, a PC plate for lining (precast concrete plate) for a plurality of spans is formed on the inner surface of the tunnel via a hinge portion, and an arch-shaped assembly lining plate is formed. However, there is a lining method in which a gap between a tunnel inner surface and an assembled lining plate is filled with a backfill material such as mortar and integrated.
The PC plate used in such a tunnel lining method has a substantially arc-shaped plate shape, and is formed by covering a steel bar with a reinforcing bar structure that incorporates main bars and distribution bars inside, and the direction of the arc shape. For example, it is formed with the same thickness of about 140 mm over the entire length. Then, an assembly lining plate in which the PC plates divided into two on the side walls placed on both sides in the circumferential direction of the tunnel are connected by hinges is built in an arch shape to perform the lining.
Japanese Patent No. 2908777

By the way, at the time of repair, there is a defect that the shoulders on both sides of the tunnel are narrowed by the thickness of the PC plate and the back-filling material by installing the assembly lining plate on the inner surface of the tunnel. Furthermore, forces such as the weight of the member itself and the load of the back-filling material before solidification during filling act on the PC plate in the circumferential direction. For this reason, since a bending moment is generated in the PC plate, it is necessary to ensure the thickness of the PC plate having a strength capable of withstanding these loads, so that the vehicle construction limit is violated when the vehicle passes. There was a problem.
And in the tunnel reinforcement work by the PC version when the vehicle building limit is violated, a board lowering work is performed to secure the vehicle building limit in the tunnel, and the roadbed is dug down. As a result, there is a step on the road surface between the exit and the entrance of the tunnel. Therefore, it is necessary to eliminate the step with the road surface outside the tunnel by forming an inclined surface, resulting in a large construction. Such panel lowering work is troublesome and has the disadvantage of extending the construction period and increasing costs.

The present invention has been made in view of the above-described problems, and has a PC plate for lining that can repair or reinforce a tunnel without violating the vehicle building limit by a structure that improves the strength of the member, and An object is to provide a mounting structure for a PC plate for lining.

In order to achieve the above-mentioned object, the PC plate for lining according to the present invention is formed in an arch shape along the inner surface with a certain distance from the inner surface of the tunnel, and is divided into two at the top end. The plate has a thin-walled structure in which a concave portion that is partially recessed toward the tunnel is formed on the inner peripheral surface, and the concave portion is protruded toward the tunnel, and the tip thereof is formed on the inner surface of the tunnel. A first support member capable of abutting is provided, and one PC plate is provided with a connecting portion for connecting to the other PC plate.
Further, the mounting structure of the PC plate for lining according to the present invention is a pair of PC plates for lining that are formed in an arch shape along the inner surface at a certain interval from the inner surface of the tunnel and divided into two at the top. In addition, a thin-walled structure is formed on the inner peripheral surface of the lining PC plate so as to form a recessed portion that is partially recessed toward the tunnel, and the recessed portion includes a first support member that protrudes toward the tunnel. The first support member has a second support member projecting toward the tunnel at or near the connecting portion to which the front end portion of the first supporting member is brought into contact with the inner surface of the tunnel and to which the divided PC plate for lining is connected It is characterized by having made it.
According to the present invention, the first support member is provided in each recessed portion of the pair of PC plates for lining, so that the tip of the first support member is brought into contact with the inner surface of the tunnel and the reaction force is applied to the tunnel. Can do. And the compressive force (force which bends the PC plate which makes a circular arc shape to the inner circumference side) which acts on the circumferential direction of the PC plate for lining by the load such as the weight of the PC plate for lining and backfilling pressure is reduced. And can resist bending on the compression side. By providing the first support member, a new fulcrum is formed on the PC plate for lining, and the fulcrum interval is reduced. Therefore, the bending moment in each PC plate for lining is not provided with the first support member. It can be made smaller than a conventional PC plate for lining.

Also, by providing the second support member near or in the vicinity of the connecting portion to which the PC plate for lining is connected, the tip of the second support member is brought into contact with the inner surface of the tunnel to take a reaction force on the tunnel. Can do. Then, when a pair of lining PC plates exerts a force for pushing up the top end (hereinafter referred to as a tensile force), a compressive force is applied in the circumferential direction of each lining PC plate. Since this is the same as a state in which pre-stress (a state in which compressive stress remains) is applied to so-called concrete, the tensile force can be reduced and the member strength of each lining PC plate can be improved.

Moreover, in the mounting structure of the PC plate for lining according to the present invention, the first support member and the second support member have a cylindrical shape in which a male screw is formed on the outer peripheral surface and a female screw is formed on the inner peripheral surface. It consists of a bolt and a second bolt that can be screwed into the inner peripheral surface of the first bolt and protruded toward the tunnel side. A female screw is formed on the inner peripheral surface in the thickness direction of the PC plate for lining It is preferable that the first bolt is screwed into the penetrating bolt hole and accommodated in the PC plate for lining.
According to the present invention, the first support member and the second support member having a two-stage bolt structure in which the second bolt screwed to the first bolt that can protrude toward the tunnel side can further protrude toward the tunnel side are provided. By providing for the PC plate for lining, the first support member and the second support member can be protruded from the tunnel to take a reaction force. The first support member and the second support member accommodated in the thickness direction of the PC plate for lining can be projected to the tunnel side with a projecting amount that is approximately twice as long. For this reason, even when the gap between the tunnel and the PC plate for lining is larger than the thickness of the PC plate for lining, the reaction force can be obtained by adjusting the protruding amount by this two-stage bolt structure.

Further, in the mounting structure of the lining for the PC version of the present invention, the first support member and second support member supporting member, the first support member and the second support in accordance with the distance between the tunnel and the lining for PC Version It is preferable to adjust the protruding amount of the member .
According to the present invention, by adjusting the amount of protrusion of the first support member and second support member, it is possible to respond to changes in the distance between the lining for the PC version and the inner surface of the tunnel, the first support member and The second support member can be brought into contact with the tunnel.

Moreover, in the attachment structure of the PC plate for lining according to the present invention, the second support member is preferably sandwiched and fixed between a pair of PC plates for lining.
According to the present invention, since the second support member can be fixed by using a connecting portion between a pair of PC plates for lining, the second support member can be fixed to both of them. Can be omitted.

Further, the partial thin structure by providing a recess in the lining for the PC version, by reducing the thickness of the lining for PC Version By installed inside the tunnel, architectural limitations to the inner space side of the tunnel Can be secured.

According to the lining PC plate and the mounting structure of the lining PC plate of the present invention, the first supporting member is provided on the inner surface of the tunnel by providing the first supporting member in the recessed portion of the pair of lining PC plates. A reaction force can be applied to the tunnel by contacting the tip. The compression force acting on the circumferential direction of the PC plate for lining by the load such as its own weight and backfilling pressure (force to bend the PC plate having an arc shape inward) can be reduced, and the compression side Can resist bending. By providing the first support member, a new fulcrum is formed on the PC plate for lining, and the fulcrum interval is reduced. Therefore, the bending moment in each PC plate for lining is not provided with the first support member. It can be made smaller than a conventional PC plate for lining.
Since the bending moment can be reduced in this way, the thickness of the lining PC plate can be reduced by reducing the thickness over the entire length or partially. Then, the tunnel can be repaired or reinforced by installing the PC lining plate on the inner surface of the tunnel without violating the vehicle construction limit. In addition, it is not necessary to perform large-scale construction such as tunnel lowering excavation, which has been performed when the vehicle construction limit is violated, and the construction period can be shortened and the construction cost can be reduced.
Further, since the bending moment acting on the PC plate for lining can be reduced, the backfilling pressure can be increased. Therefore, it is possible to increase the height of one-time driving of the back-filling material, and to reduce the number of times of driving, so that the construction speed can be increased, the construction period can be shortened, and the construction cost can be reduced.

Hereinafter, a lining PC plate and a lining PC plate mounting structure according to an embodiment of the present invention will be described with reference to FIGS. 1 to 11.
FIG. 1 is a longitudinal sectional view of a tunnel after repair according to an embodiment of the present invention, FIG. 2 is a view showing a connection structure at the top end of a PC plate, and FIG. 3 is a view showing an installation state of first and second support members 4 is an enlarged view of the third support member shown in FIG. 3, FIG. 5 is an enlarged view of the second support member shown in FIG. 3, and FIG. 6 is an explanatory view of the self-weight action in the conventional PC plate, (A) is a diagram showing the load distribution, (b) is a diagram showing the bending moment, FIGS. 7 (a) to (c) are explanatory diagrams of the self-weighting action in the PC plate of the embodiment, and FIG. 8 (a). FIGS. 9A and 9B are explanatory diagrams of backfilling pressure action in the conventional PC plate, FIGS. 9A and 9B are explanatory diagrams of backfilling pressure action in the conventional PC plate, and FIG. FIGS. 11A and 11B are explanatory views of the backfill pressure action in the PC plate of the embodiment, and FIGS. 11A and 11B are the same in the PC plate of the embodiment. It is an explanatory diagram for backfill compaction.

  FIG. 1 shows an existing tunnel 1 after repair. The tunnel 1 is formed of reinforced concrete having a predetermined thickness and a substantially arched lining. And the side walls 2 and 2 made from, for example, cast-in-place concrete are constructed inside the left and right side walls 1a and 1a that stand on the road surface of the tunnel 1. Then, for the pair of left and right substantially arc-shaped PC plates 3 and 4 (hereinafter simply referred to as PC plates), the upper ends 3a and 4a are joined at the top end and embedded at the lower ends 3b and 4b. The fixing bolts 5 and 5 are positioned and fixed to the upper ends of the side walls 2 and 2. The left PC plate shown in FIG. 1 will be described as a first PC plate 3, and the right PC plate will be described as a second PC plate 4.

As shown in FIG. 2, the upper ends 3 a and 4 a of the first and second PC plates 3 and 4 are alternately fitted with stepped portions composed of convex portions and concave portions, and two through holes 3 c provided in both convex portions. The long bolt 6 is inserted into 4 c and the end portions 6 a and 6 a are connected and fixed by the high nut 7. As a result, a connecting portion T to be hinged is formed.
Further, as shown in FIG. 1, height adjusting bolts 5 and 5 protrude toward the upper end surfaces of the side walls 2 and 2 at the lower ends 3b and 4b, and the protruding amount of the bolts 5 and 5 is adjusted. It can be positioned on the side walls 2 and 2. Thus, the pair of PC plates 3 and 4 can be connected to each other to form a substantially semicircular arch shape on the side walls 2 and 2.
As shown in FIG. 1, a backfill material 8 is filled in a gap between the tunnel 1 and a pair of installed PC plates 3 and 4.

  The pair of PC plates 3 and 4 are formed in, for example, a substantially ¼ arc shape as shown in FIG. 1 when viewed in the radial direction, and the outer peripheral surfaces 3d and 4d on the tunnel 1 side have a simple substantially circular shape. It is formed in an arc shape, and the inner peripheral surfaces 3e and 4e form a recessed portion 9 that is recessed toward the tunnel 1 (outside) in the central region. Therefore, each of the PC plates 3 and 4 forms a thin part S having a small thickness with the concave part 9 recessed outward, and both sides in the arc direction of the thin part S have a thickness projecting inward from the thin part S. It has a partially thin structure in which large side portions 3f and 4f are formed. When the thickness of the side portions 3f and 4f is, for example, 140 mm, the thickness of the thin portions S and S is set to 80 mm or less.

  As shown in FIG. 1 and FIG. 3, the first support member that protrudes toward the tunnel 1 with a predetermined protrusion amount and contacts the inner surface of the tunnel 1 in the recessed portions 9 and 9 of the pair of PC plates 3 and 4. 10 and 10 are built in. At this time, the positions of the first support members 10 and 10 are approximately 45 ° in the radial direction from the center of the arc of the PC plates 3 and 4. In addition, a second support member 11 is fixed to the connecting portion T of the pair of PC plates 3 and 4 so that the tip portion 11a having a pointed shape can protrude toward the tunnel 1 side.

As shown in FIGS. 4 (a) and 4 (b), each PC plate 3, 4 forming the built-in position of the first support member 10, 10 has bolt holes 3g, 4g penetrating in the thickness direction of the PC plate. An internal thread is formed on the inner peripheral surface of the bolt holes 3g, 4g. The first support member 10 is a first bolt 10b having a cylindrical shape in which a male screw is formed on the outer peripheral surface and a female screw is formed on the inner peripheral surface, and a second bolt that is screwed to the inner peripheral surface of the first bolt 10b. It consists of a bolt 10c. A tip 10a is provided at the end of the second bolt 10c on the tunnel 1 side. And the outer peripheral surface of the 1st volt | bolt 10b and the internal thread of the bolt hole 3g (4g) screw together, and are built in each PC plate 3 and 4. FIG.
In this way, the first support member 10 has a two-stage bolt structure in which the second bolt 10c that is screwed into the first bolt 10b that can project to the tunnel 1 side can further project to the tunnel 1 side. ing.
And the 1st support member 10 is accommodated in the thickness direction of each PC plate 3 and 4, and can protrude in the tunnel side by the protrusion amount of about twice the length. Therefore, even when the gap between the tunnel 1 and each of the PC plates 3 and 4 is larger than the thickness of the PC plates 3 and 4, the protruding amount of the first bolt 10b and the second bolt 10c by this two-stage bolt structure is adjusted. The tip 10a can be brought into contact with the inner surface 1c (see FIG. 3) of the tunnel 1 to take a reaction force.

Further, as shown in FIG. 5, the second support member 11 is sandwiched between the convex portions of the PC plates 3 and 4 in the connecting portion T and is fixed by the fixing nut 11 b with the long bolt 6 passing therethrough. A mold steel material 11c, an adjustment nut 11d fixed to the upper surface of the L-shaped steel material 11c, and a projecting bolt 11e having a tip 11a at one end and a screw formed so that the other end is screwed to the adjustment nut 11d. It is composed of And the front-end | tip part 11a of the protrusion volt | bolt 11e is made to contact | abut to the top end 1b of the tunnel 1 by adjusting the protrusion amount of this protrusion volt | bolt 11e. In addition, the process for attaching the 2nd support member 11 to the PC plates 3 and 4 can be omitted by using the connection part T in this way.
In addition, since the front-end | tips 10a and 11a of the 1st and 2nd support members 10 and 11 are pointed, the inner surface 1c of the tunnel 1 which makes a to-be-contacted surface is a natural ground which has an uneven part instead of concrete. Can also be reliably contacted (see FIG. 3).

Next, the action of force in the pair of PC plates 3 and 4 provided with the first support member 10 and the second support member 11 according to the present embodiment will be described with reference to the drawings.
First, in an example showing this embodiment, a description will be given in comparison with a conventional example including a pair of PC plates not provided with the first and second support members 10 and 11. In the conventional example, the left side is referred to as the first PC plate 13 and the right side in the drawing is referred to as the second PC plate 14 in order to distinguish left and right shown in FIG.
As shown in FIG. 6A and FIG. 7A, the conventional PC boards 13 and 14 and the PC plates 3 and 4 of the embodiment are connected to the connecting point P1 that forms the connecting part T at the top and the side wall 2 ( It is supported at three points, fixed points P2 and P3 installed in FIG. In the embodiment, the point where the second support member 11 is installed is the support point Q1, and the points of the PC plates 3 and 4 where the first support members 10 and 10 are installed are the support points Q2 and Q3.

  As shown in FIGS. 6 (a) and 7 (a), the conventional PC boards 13 and 14 and the PC plates 3 and 4 of the embodiment are installed on a predetermined position in the tunnel 1 (not shown). ) Is supported from the air side of the tunnel. When the gantry is moved after installation, the support from the air side in the tunnel is removed, and the own weight G1 acts on the PC plates 3, 4, 13, and 14.

  As shown in the load distribution of the conventional example in FIG. 6A, since the pair of PC plates 13 and 14 are in a state where the fixing points P2 and P3 are fixed, the connecting point P1 forming the hinge portion by the own weight G1 is A force acts vertically downward (arrow H direction). Then, each of the PC plates 13 and 14 having an arc shape acts so that the end portions 13a and 14a in the vicinity of the connection point P1 are lowered toward the inner side of the tunnel, so that the PC plates 13 and 14 having the arc shape are inward. A bending force acts on the circumferential side, and a circumferential compressive force F1 (I direction in the figure) acts. 6B, the bending moment M1 on the compression side is distributed for each of the PC plates 13 and 14, and the bending moment M from the arc center of the PC plates 13 and 14 is approximately 45 ° in the radial direction. It becomes maximum at a position (hereinafter simply referred to as 45 ° obliquely).

  In the pair of PC plates 3 and 4 in the embodiment, as shown in FIG. 7A, the first support members 10 and 10 project and protrude from the inner surface side of the tunnel 1 at the support points Q2 and Q3. For this reason, at the support points Q2 and Q3, a reaction force (arrow J) that opposes the bending caused by the own weight G1 is generated, and the compression force F1 is reduced. As shown in FIG. 7B, the bending moment M at this time has the bending moment M2 on the compression side distributed on both sides of the supporting points Q2 and Q3 as fulcrums. The magnitude of the bending moment M2 is smaller than the bending moment M1 of the conventional example shown in FIG. 6B, and the maximum bending moment M2 can be reduced to, for example, about ½ of the maximum bending moment M1 of the conventional example.

  In addition, the reaction force (arrow J) at the support points Q2 and Q3 shown in FIG. 7A applies a tensile force F2 in the direction of the arrow L to each PC plate 3 and 4, and the connection point P1 at the top end is indicated by the arrow L. A force pushing up in the direction acts. On the other hand, since the second support member 11 is provided at the support point Q1 and the reaction force is applied to the tunnel 1, a reaction force that opposes the tensile force F2 acts and a compression force is applied to each of the PC plates 3 and 4. F1 (arrow I) can be introduced. As shown in FIG. 7C, the bending moment M3 at this time is larger than the bending moment M2 shown in FIG. 7B by the amount of the compression force F1 introduced. Thus, the strength of the member can be improved by allowing the PC plates 3 and 4 to remain in a state where the compression force F1 is introduced.

Next, the action of force in the conventional example and the example when filling the backfill material 8 will be described.
The backfilling material 8 before solidification during filling receives a pressure corresponding to the height to be filled with the PC plate. And the supply method of the backfilling material 8 supplies alternately by right and left with predetermined | prescribed placement height so that a partial load may not be applied to the PC plate of one side. The supply length in the tunnel traveling direction to be supplied once is set to about 200 m that can be pumped by a pump, for example.
The conventional example shown in FIG. 8A shows the load distribution when the backfilling material 8 is supplied to the back surface of the lower end 13b of the first PC plate 13, and the pair of PC plates 13 and 14 depend on the backfilling material 8. The backfilling pressure G2 and the dead weight G1 are acting. Due to the backfill pressure G2, a force acts on the lower end 13b of the first PC plate 13 on the filling side toward the inner side of the tunnel in the direction of the arrow N, and the compression force F1 is applied to the second PC plate 14 via the connection point P1. Works. As shown in FIG. 8B, the bending moment M4 at this time is distributed in the tension side bending moment M4 in the first PC plate 13, and is distributed in the compression side bending moment M5 in the second PC plate 14. .

As shown in FIG. 9A, when the backfilling material 8 is solidified after a certain time, the lower end 13b of the PC plate 13 and the tunnel 1 are integrated in the filled backfilling material 8 region. A ground spring region R is formed. In this ground spring region R, a reaction force is exerted against the compression side bending acting on the first PC plate 13, and therefore the compression side bending is reduced.
Next, when the backfilling material 8 is supplied to the lower end 14b of the second PC plate 14 facing the lower end 13b, the backfilling pressure G2 acts. Then, the compression force F1 acts in the circumferential direction of the first PC plate 13 via the connection point P1, and the first PC plate 13 is bent on the compression side.
As shown in FIG. 9B, the bending moment M at this time is reduced in the ground spring region R, so that the bending moment M6 on the compression side is distributed above the ground spring region R.

On the other hand, as shown in the load distributions of FIGS. 10A and 11A, in the embodiment when the backfilling material 8 is filled, the own weight G1 and the backfilling pressure G2 act as in the conventional example. ing.
In the pair of PC plates 3 and 4 in the embodiment, as shown in FIG. 10A, the backfill pressure G2 is applied to the lower end 3b of the first PC plate 3, and the bending on the compression side acts on the second PC plate 4. Then, a reaction force (arrow J) that opposes bending acts by the first support member 10 at the support point Q3, and the compression force F1 is reduced.
The reaction force at the support point Q3 causes a tensile force F2 to act on the second PC plate 4 and a force to push up the connecting point P1 at the top end in the direction of the arrow L. On the other hand, a reaction force that opposes the tensile force F2 acts by the second support member 11 at the support point Q1, and the compression force F1 can be introduced into the second PC plate 4. As shown in FIG. 10B, the bending moment M7 at this time is distributed on the compression side with the support point Q3 that does not generate the bending moment M as a fulcrum.

FIGS. 11A and 11B show the case where the backfilling pressure G2 acts on the second PC plate 4 side, but the action of the ground spring region R described in the conventional example of FIG. Since it becomes the effect | action which added the effect | action of the 1st and 2nd support members 10 and 11 demonstrated in the Example of this, description is abbreviate | omitted.
The magnitudes of the bending moments M7 and M8 in the embodiment shown in FIGS. 10B and 11B are smaller than the bending moments M5 and M6 in the conventional example shown in FIGS. 8B and 9B, respectively. Become.

As described above, in the mounting structure of the PC plate for lining and the PC plate for lining according to the embodiment, by providing the first support member 10 at the support points Q2, Q3 of the pair of PC plates 3, 4, the tunnel 1 The reaction force can be taken, and the compression force F1 acting by the own weight G1 or the backfill pressure G2 can be reduced to counter the bending on the compression side. And since a new fulcrum is formed in each PC plate 3 and 4, and a fulcrum space | interval becomes small, the bending moment M in each PC plate 3 and 4 is made into the conventional PC plate 13 which is not equipped with the 1st support member 10, Compared to 14, it can be made smaller.
Since the bending moment M of the first support member 10 can be reduced in this way, the thickness of each PC plate 3, 4 can be made thin by thinning the entire length or partially in the circumferential direction. For example, the thickness of the recess 9 shown in FIG. 1 can be set to 80 mm. Therefore, by making the PC plates 3 and 4 have a thin structure, the PC plates 3 and 4 are installed on the inner surface of the tunnel 1 without invading the vehicle construction limit K (see FIG. 1), so that the tunnel can be repaired or reinforced. It can be carried out. In addition, it is not necessary to perform large-scale construction such as tunnel lowering excavation, which has been performed when the vehicle construction limit K is violated, and the construction period can be shortened and the construction cost can be reduced.
Furthermore, since the bending moment acting on the PC plate for lining can be reduced, the backfill pressure G2 can be increased correspondingly. Therefore, it is possible to increase the height of the back-filling material 8 once, and the number of times of driving can be reduced. Therefore, the construction speed can be increased, the construction period can be shortened, and the construction cost can be reduced. In particular, in the case where the construction is carried out with one side lane restricted, such as repair work under live line conditions, it may be required to increase the construction speed, and the effect is increased.

  Further, in the mounting structure according to the embodiment, when the tensile force F2 acts on the pair of PC plates 3 and 4 and the pushing force acts on the connection point P1, the second support member 11 is applied to the support point Q1 of the top end portion. By providing a reaction force on the tunnel 1, the compressive force F <b> 1 can be applied in the circumferential direction of the first and second PC plates 3 and 4. This is the same as a state in which pre-stress (a state in which compressive stress remains) is applied to so-called concrete, so that the tensile force F2 can be reduced, and the strength of each PC plate 3, 4 can be improved. Can do.

Having described embodiments of a mounting structure of a PC version and lining for the PC version for lining according to the present invention, this invention is not limited to the above embodiments, without departing from its spirit scope It can be changed as appropriate.
For example, in the embodiment according to the present invention, the mounting position of the second support member 11 is the top end connection portion T, but the present invention is not limited to this, and it may be in the vicinity of the connection portion T or the connection point P1. In addition, the first support member 10 is set at a 45 ° oblique position where the maximum bending moment M is obtained, but is not necessarily limited to this 45 ° oblique position.
Furthermore, in the embodiment according to the present invention, the number of the first and second support members 10 and 11 is three, but the number is not limited to this. For example, the second support member 10 may be provided at two positions on both sides of the connection point P1, and the first support member 10 may be provided at two positions on each of the first and second PC plates 3 and 4. Absent.
In the embodiment, the support method for forming the support point Q1 is a method in which the L-shaped steel material 11c of the second support member 11 is sandwiched and fixed using the connecting portion T, but is limited as shown in this method. It will never be done. For example, the first support member 10 incorporated in the PC plate may be used, and may be provided on either the end 3a or 4a of the PC plates 3 and 4 instead of the connecting portion T.
The support member is not limited to the first and second support members 10 and 11 according to the embodiment. For example, a long bolt or the like may be penetrated in the thickness direction of the PC plates 3 and 4 to serve as the support member. It doesn't matter.

It is a longitudinal cross-sectional view of the tunnel after the repair by embodiment of this invention. It is a figure which shows the connection structure in the top end of PC version. It is a figure which shows the installation state of a 1st and 2nd support member. FIG. 4 is an enlarged view of the first support member shown in FIG. 3. It is an enlarged view of the 2nd support member shown in FIG. It is explanatory drawing of the dead weight effect | action in the PC version of a prior art example, Comprising: (a) is a figure which shows the load distribution, (b) is a figure which shows the bending moment. It is explanatory drawing of the dead weight effect | action in PC version of an Example, Comprising: (a) is a figure which shows the load distribution, (b), (c) is a figure which shows the bending moment. It is explanatory drawing of the backfilling pressure effect | action in the PC plate of a prior art example, Comprising: (a) is a figure which shows the load distribution, (b) is a figure which shows the bending moment. It is explanatory drawing of the backfilling pressure effect | action in the PC plate of a prior art example, Comprising: (a) is a figure which shows the load distribution, (b) is a figure which shows the bending moment. It is explanatory drawing of the backfilling pressure effect | action in the PC plate of an Example, (a) is a figure which shows the load distribution, (b) is a figure which shows the bending moment. It is explanatory drawing of the backfilling pressure effect | action in the PC plate of an Example, (a) is a figure which shows the load distribution, (b) is a figure which shows the bending moment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tunnel 2 Side wall 3, 13 1st PC plate 4, 14 2nd PC plate 8 Backing material 9 Recessed part 10 First support member 10b First bolt
10c Second bolt 11 Second support member G1 Own weight G2 Backfill pressure F1 Compressive force F2 Tensile force M Bending moment R Ground spring region T Connecting part K Vehicle construction limit

Claims (5)

A pair of lining PC plates formed in an arch shape along the inner surface at a certain interval from the inner surface of the tunnel and divided into two at the top ,
On the inner peripheral surface, it has a thin structure in which a recessed portion that is partially recessed toward the tunnel is formed,
The recessed portion is provided with a first support member that protrudes toward the tunnel, and that allows the tip portion to abut against the inner surface of the tunnel,
One PC plate is provided with a connecting portion for connecting to the other PC plate. A mounting structure for a pair of lining PC plates formed in an arch shape along the inner surface at a certain interval from the inner surface of the tunnel and divided into two at the top end,
On the inner peripheral surface of the PC plate for lining, a thin-walled structure that forms a recessed portion that is partially recessed toward the tunnel side is formed,
The concave portion includes a first support member that protrudes toward the tunnel, and a tip portion of the first support member is brought into contact with an inner surface of the tunnel,
A PC board for lining, comprising a connecting portion to which the PC plate for lining divided into two parts is connected or a second support member protruding toward the tunnel in the vicinity of the connecting part . Mounting structure. The support member is
A first bolt having a cylindrical shape in which a male screw is formed on the outer peripheral surface and a female screw is formed on the inner peripheral surface;
A second bolt that is screwed into the inner peripheral surface of the first bolt and is provided so as to protrude toward the tunnel side;
Consists of
An internal thread is formed on the inner peripheral surface, and the first bolt is screwed into a bolt hole penetrating in the thickness direction of the lining PC plate so as to be accommodated in the lining PC plate. The mounting structure of a PC plate for lining according to claim 2 . 4. The PC plate for lining according to claim 2, wherein the support member is configured to adjust a protruding amount of the support member in accordance with an interval between the tunnel and the PC plate for lining. Mounting structure. The mounting structure of a PC plate for lining according to claim 2, wherein the second support member is sandwiched and fixed between the pair of PC plates for lining.

Images