JP2001132393A - Segment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the installation of a PC steel material and enable their exchange. SOLUTION: A segment Sa and other plurality of segments are annularly arranged, and the PC steel material P is inserted in an anchor groove 1b from one sheath pipe 6 of the segment Sa, inserted in insertion holes 1f of the whole segments formed of distributing bars 3 and suspension bars 5, and drawn out of the other sheath pipe 6 to the outside. When the tip of the PC steel material P abuts on the distributing bar 3, the suspension bar 5, or a level difference of the anchor groove 1b, this can be visually observed and easily detached from the distributing bar 3, etc., so that the PC steel material P can be quickly and surely inserted and installed. When the PC steel material is damaged, it can be easily exchanged for a new one.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PC (precast) segment which can be integrally joined with a PC steel material.

[0002]

2. Description of the Related Art When a tunnel is constructed by a shield method, a plurality of segments curved in an arc shape are integrally connected with a PC steel material. The conventional segments Sf and Sg of FIG. 8 that realize the above are provided with the sheath tube 21 or the sheath tube 22 and the fixing device 23, and the PC steel material P is annularly arranged from one of the pipe members 23a of the fixing device 23. Of the sheath tubes 22, 21,
The PC steel material P is pulled out of the other pipe member 23b successively through 21, 21, 21 and 22, and the PC steel material P is tensioned by the hydraulic jack 24 so that both ends can be fixed as it is. The fixing device 23 is made of a casting,
The pipe members 23a and 23b are integrally formed in an X shape.

[0003]

The above-mentioned conventional segments Sf and Sg, when they are single, have a sheath tube 2
It is easy to insert the PC steel material P into the sheath pipes 1 and 22, but when a plurality of segments Sf and Sg are assembled in a ring shape, a slight step is easily generated between the sheath pipes 21 and 22. Since the tip of the PC steel material P can be used for the step, it is not easy to insert the PC steel material P into the sheath pipes 21 and 22, and there is a problem that it takes time and effort.

For the above reasons, it is necessary to increase not only the accuracy of the embedding position of the sheath tubes 21 and 22 but also all the accuracy, which is disadvantageous in cost. Further, since the PC steel P is inside the sheath pipes 21 and 22, the damage cannot be seen from the outside, and furthermore, as time passes, the insertion environment of the PC steel P has changed from the beginning of the construction of the tunnel. Therefore, even if the PC steel material P can be pulled out from the sheath tubes 21 and 22, there is no guarantee that the PC steel material P can be inserted again into the sheath tubes 21 and 22. There is also a problem that it cannot be replaced with a new one.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a segment in which a PC steel material can be easily installed. Another object of the present invention is to provide a PC
An object of the present invention is to provide a segment capable of reducing manufacturing costs with less restrictions on forming accuracy related to steel materials. Another object of the present invention is to provide a P
The purpose of the present invention is to provide a segment in which C steel can be replaced.

[0006]

In order to achieve at least one of the above objects, according to the present invention, a fixing groove of PC steel is formed on an inner peripheral surface of a segment body curved in an arc shape. Inserts holes of PC steel are formed at several places by partially traversing reinforcing bars such as distribution bars and suspension bars embedded in the main body, and both ends are opened at both joint surfaces in the curved direction of the segment main body. A configuration was provided in this way.

In this means, a PC steel material is inserted into a fixing groove and inserted into an insertion hole formed by a reinforcing bar such as a suspension bar. Reinforcing bars such as suspension bars in the insertion holes receive the tensioned PC steel material and prevent the PC steel material from coming off the fixing groove. Because the PC steel in the fixing groove can be seen, even if the tip of the PC steel comes into contact with a reinforcing bar such as a suspension bar and does not move forward when passing the PC steel through the fixing groove, Immediately, the contact tip can be removed from a reinforcing bar such as a suspension bar, and the insertion of the PC steel can be continued. Further, it is possible to know the damage of the PC steel after the construction of the tunnel and replace the PC steel as necessary.

According to a second aspect of the present invention, a projection is formed substantially at the center of the inner peripheral surface of the segment body curved in an arc shape in the bending direction, and one of the joining surfaces of the segment body in the bending direction and the projection are formed. A fixing groove made of PC steel is embedded in the segment body on the inner peripheral surface between the inner surface and the inner peripheral surface between the other joint surface and the projection, and the distribution and suspension bars are also used as the jack thrust-resistant material. The steel tube is partially traversed at a plurality of locations and a PC steel material insertion hole is formed in the portion and provided. The same number of sheath tubes as the fixing grooves are provided in the protrusions, and the inner ends are provided in the fixing grooves. The protruding portion was buried by communicating with the outer end of the protruding portion.

In this means, the tip of the PC steel material is inserted from the outer end of the sheath tube and fed to another segment through the fixing groove. In addition, the leading end of the PC steel material that has exited the other segment is guided from the fixing groove to the inner end of the sheath tube, and exits from the outer end. Also in the case of this segment, the reinforcing bar such as the suspension bar at the insertion hole portion of the fixing groove receives the tensioned PC steel material and prevents the PC steel material from coming off the fixing groove. Further, it is possible to find and remove the contact of the tip of the PC steel material with a reinforcing bar such as a suspension bar, and to easily replace the damaged PC steel material. The protruding portion is used as a reaction force receiver for a hydraulic jack or the like when the PC steel is prestressed by a hydraulic jack or the like.

According to a third aspect of the present invention, a projection is formed substantially at the center of the inner peripheral surface of the segment body curved in an arc shape in the bending direction, and one of the joining surfaces in the bending direction of the segment body and the projection are formed. The fixing groove of PC steel is formed on the inner peripheral surface between the joints and the inner peripheral surface between the other joint surface and the protrusion, and reinforcing bars such as force distribution bars and suspension bars embedded in the segment body are provided at a plurality of locations. An insertion hole for PC steel material is formed in the portion so as to cross the portion, and the same number of end grooves as the fixing grooves are provided in the protrusion, and reinforcing bars such as distribution bars and suspension bars embedded in the protrusion. Was partially crossed at a plurality of locations, a PC steel material insertion hole was formed in that portion, and the inner end was communicated with each of the fixing grooves, and the outer end was provided with an opening at the end face of the projection. .

In this means, the front end of the PC steel material is inserted from the outer end of the end groove, and is sent to another segment through the fixing groove. In addition, the tip of PC steel which came out of another segment
It is guided from the fixing groove to the inner end of the end groove, and exits from the outer end. In this segment, the reinforcing bars such as suspension bars at the insertion holes of the fixing groove and the end groove receive the tensioned PC steel material and prevent the PC steel material from coming off from the fixing groove and the end groove.
Further, the contact of the tip of the PC steel material with a reinforcing bar such as a suspension bar can be found and removed, and the damaged PC steel material can be easily replaced. The protruding portion is used as a reaction force receiver for a hydraulic jack or the like when the PC steel material is prestressed by a hydraulic jack or the like.

In the segment according to the first aspect, a projection can be formed substantially at the center of the inner peripheral surface of the segment body in the bending direction (claim 4). In this configuration, for example, when a tunnel is constructed by shifting the segment described in claim 2 or 3 by one in the circumferential direction when viewed from the front of the tunnel, the projection does not continue in the tunnel construction direction as it is. In such a case, by using this segment, the protrusions can be made continuous in the tunnel construction direction.

[0013] In the segment according to any one of claims 1 to 4, it is preferable that anticorrosion treatment is performed on reinforcing bars such as distribution bars and suspension bars in the insertion hole portion (claim 5). In this configuration, the reinforcing bars such as the distribution bars and the suspension bars in the insertion hole portion are hardly corroded, and thus the durability of the tunnel is improved.

[0014]

Embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 4 show a first embodiment of a segment according to the present invention. This segment Sa
In a concrete segment body 1 in which a main bar 2 (rebar) and a distribution bar 3 (rebar) are embedded, a projection 1a, a suspension bar 5 (rebar), a fixing groove 1b, and a sheath tube 6 are provided. It is provided.

The projecting portion 1a is located substantially at the center of the inner peripheral surface 1c of the segment body 1 curved in an arc shape.
It is formed of the same material as that of concrete, that is, trapezoidal made of concrete. The suspension bar 5 is buried in the portion of the segment body 1 where the fixing groove 1b is to be formed.

The fixing groove 1b has an inner peripheral surface 1c between one joint surface 1d in the bending direction of the segment main body 1 and the projection 1a.
And an inner peripheral surface 1c between the other joint surface 1d and the protrusion 1a.
2 (total 4), parallel to each other at the 1/4 position and 3/4 position in the width direction (vertical direction in FIG. 1) of the segment body 1 along the bending direction of the segment body 1 and the force distribution. The streak 3 and the suspension streak 5 are partially crossed at a plurality of places (four places in the figure), and an insertion hole 1f for the PC steel material P is formed in the part. The cross-sectional shape of the fixing groove 1b is substantially U-shaped (V-shaped).

The number of the sheath tubes 6 is equal to the number of the fixing grooves 1b, and the inner ends 6a communicate with the fixing grooves 1b, and the outer ends 6b are opened to the end surfaces of the protrusions 1a. It is buried inside the partial force bars 3 and the suspension bars 5. The end face of the projection 1a is formed such that its extension line substantially coincides with the center of the arc of the segment body 1,
The outer end 6b of the sheath tube 6 is perpendicular or acute to the end surface of the projection 1a.

FIG. 5 shows a second embodiment of the segment according to the present invention. This segment Sb is obtained by omitting the sheath tube 6 from the above-described segment Sa, and forming an end groove 1g in that portion.
Is formed. The end groove 1g partially crosses the force distribution bars 3 and the suspension bars 5 buried in the projections 1a at a plurality of locations (five locations in FIG. 5), and the insertion holes 1h for the PC steel material P in the portions.
(In FIG. 5, it exists below the force distribution muscle 3 and the suspension muscle 5.) The inner end communicates with the fixing groove 1b, and the outer end is formed on the end surface of the projection 1a in the same manner as the sheath tube 6. The opening is provided vertically or at an acute angle. This segment S
Since the other structure of b is the same as that of the segment Sa in FIGS. 1 to 4, the same members and the like are denoted by the same reference numerals and description thereof is omitted.

FIG. 6 shows a third embodiment of the segment according to the present invention. In this segment Sc, the projection 1a and the sheath tube 6 are omitted from the segment Sa described above, and the projection 1
a, the fixing grooves 1b, 1b on the left and right
The structure is continuous with the book. This segment Sc
Since the other structure is the same as that of the segment Sa in FIGS. 1 to 4, the same reference numerals are given to the same members and the like, and the description thereof is omitted.

The segment Sd in FIG.
A projection 1a is provided substantially at the center of the inner peripheral surface 1c in the bending direction, and the side surface shape is made to match the side surface shape of the segments Sa and Sb. The fixing groove 1b is formed so as to be continuous with the protrusion 1a.

Next, the segments Sa and S according to the present invention will be described.
The functions of b, Sc, and Sd will be described together with examples of their use.
FIG. 7 shows a tunnel T using a segment according to the present invention.
In this example, one segment Sa and five segments Sc are used. Segment Sa, S
c is arranged in an annular shape as is well known by the implementation of the shield method. After arranging the segments Sa and Sc, the PC steel material P is transferred from one sheath tube 6 of the segment Sa to the fixing groove 1b.
To be inserted into the insertion holes 1f of the segments Sa and Sc, and pulled out of the other sheath tube 6 to the outside.

During this operation, the tip of the PC steel material P
When the PC steel material P hits the suspension 5 or the like, the forward movement of the PC steel material P is hindered. However, the PC steel material P can be easily removed from the distribution bars 3 and the like by visually recognizing this. It can be done quickly and reliably. Also, if there is a step between the fixing grooves 1b, 1b of the adjacent segments due to an error in the molding of the segment or an error in the assembly of the tunnel, the step is absorbed to absorb the PC steel P.
Can be installed without hindrance. Therefore, restrictions on the accuracy of dimensions or assembly of the segments Sa and Sc and the tunnel T are eased, which is advantageous in terms of cost.

As described above, each segment Sa, Sc
The PC steel material P inserted into the annular shape is tensioned by a hydraulic jack or the like to apply prestress, and the construction of the tunnel T is completed while maintaining the state.

In the above-described construction of the tunnel T, it is possible to freely observe the temporal damage and the like of the PC steel material P, and moreover, the insertion environment of the PC steel material P may change with time. Can also replace the PC steel material P.
If necessary, the concrete T is filled into the fixing groove 1b to finish the tunnel T. In this case, the PC steel P can be replaced by peeling of the filled concrete.

In the tunnel T shown in FIG.
The same operation and effect can be obtained by using the segment Sb instead of a. The end groove 1g of the segment Sb is filled with ready-mixed concrete, if necessary, similarly to the fixing groove 1b. When the tunnel T is constructed by extending in the direction perpendicular to the paper surface in FIG. 7, the segments Sa (Sb) are shifted by one in the circumferential direction, for example, as indicated by a two-dot chain line in the range of the lower three. May be placed. In this construction method, the projection 1a is not continuous in the construction direction of the tunnel T,
There may be some inconvenience. In such a case, in the example of FIG. 7, the two segments Sd having the protrusions 1a are replaced with the two segments Sc, and the protrusions 1a are made continuous in the tunnel T construction direction.

At least the distributing bars 3 and the suspension bars 5, which are exposed in the fixing grooves 1b and the end grooves 1g and form the insertion holes 1f and 1h, are usually subjected to anticorrosion treatment to increase durability. As the unbonded PC steel material P, a coated PC steel wire or a PC steel stranded wire is usually used. In addition, a steel plate or the like can be used for the suspension bar 5 in addition to the round steel. The suspension bars 5 are fixed to the distribution bars 3 or the like by welding or other means as necessary.

The protruding portion 1a is used as a reaction force receiver for the hydraulic jack or the like when the PC steel material P is prestressed by the hydraulic jack or the like. In this case, as described above, the protruding portion 1a is Since the extension of the end face is formed substantially in line with the center of the arc of the segment main body 1, the outer ends of the sheath tube 6 and the end groove 1g are perpendicular or acute to the end face of the projection 1a. The hydraulic jack or the like is stabilized on the end face of the projection 1a without moving toward the center of the tunnel. The shape of the end face of the projection 1a is not limited to the above, and in some cases, another member may be inserted into the fixing groove 1b to receive the reaction force. Segments Sa and S in the figure
Each of b, Sc, and Sd has a structure in which two PC steel materials P are inserted, but may have a structure in which one or three or more PC steel materials P are inserted.

Incidentally, the introduction force Np of the PC steel material P is represented by the following equation (1). Np = Pi × Rc (1) where: Pi; central force per unit length in the circumferential direction Rc; radius of the inserted state of PC steel material P Suspension line 5 and distribution line 3 are Pi (= Np / Rc) Are arranged at a pitch that can sufficiently withstand the above. Therefore, the number of distributing bars 3 and suspension bars 5 is not limited to those shown in the figure.

The segments Sa, Sb, Sc,
Sd is designed to receive the prestress of the PC steel material P by both the force distribution bars 3 and the suspension bars 5, but it is also possible to adopt a structure in which only the suspension bars 5 receive the prestress, or in some cases, the suspension bars 5
Can be omitted and the structure can be received only by the power distribution muscle 3. Further, a steel plate or the like may be used. The positions in the thickness direction of the segment main body 1 of the distribution muscles 3 and the suspension muscles 5 are not limited to those shown in the drawings, and may be on the inner circumferential side or the outer circumferential side. The conventional fixing device 23 shown in FIG. 8 can be used in place of the sheath tubes 6 and 6 provided on the projection 1a of the segment Sa.

[0030]

As described above, according to the present invention,
Easy insertion and installation work of PC steel material, with less restrictions on molding accuracy and assembly accuracy, reducing cost, and replacing PC steel material with new one if necessary after tunnel construction. It is possible to obtain a segment having excellent economic efficiency.

[Brief description of the drawings]

FIG. 1 is a partially broken plan view showing a first embodiment of a segment according to the present invention.

FIG. 2 is a partially cutaway front view of the segment of FIG. 1;

FIG. 3 is a sectional view of a portion (III-III) in FIG. 2;

FIG. 4 is a cross-sectional view taken along a line (IV-IV) in FIG. 2;

FIG. 5 is a plan view showing a second embodiment of the segment according to the present invention.

FIG. 6 is a plan view showing a third embodiment of the segment according to the present invention.

FIG. 7 is a front view showing an example of constructing a tunnel using the segments of the present invention.

FIG. 8 is a front view of a tunnel constructed by conventional segments.

[Explanation of symbols]

Sa, Sb, Sc, Sd Segment P PC steel 1 Segment main body 1a Projection 1b Fixing groove 1c Inner peripheral surface 1d Joining surface 1f, 1h
Insertion hole 1g End groove 2 Main bar 3 Distributing bar (rebar) 5 Suspension bar (rebar) 6 Sheath tube 6a Inner end 6b Outer end T Tunnel

Claims (5)

[Claims] 1. A fixing groove made of PC steel is formed on an inner peripheral surface of a segment body curved in an arc shape by partially traversing a reinforcing bar such as a distribution bar or a suspension bar embedded in the segment body at a plurality of locations. A segment, wherein a through-hole of a PC steel material is formed in a portion thereof, and both ends are provided so as to be opened at both joint surfaces in the bending direction of the segment body. 2. A projection is formed at substantially the center of the inner peripheral surface of the segment body curved in an arc shape in the bending direction, and an inner peripheral surface between one of the joining surfaces of the segment body in the bending direction and the projection. A fixing groove made of PC steel is embedded in the segment body on the inner peripheral surface between the other joint surface and the projection, and a plurality of reinforcing bars or steel materials such as distributing bars and suspension bars which also serve as jacking thrust members are provided. It is provided by forming a through-hole of PC steel material in that part partially across the part,
A segment, wherein the same number of sheath tubes as the number of the fixing grooves are embedded with the inner ends communicating with the fixing grooves and the outer ends opened at the end surfaces of the protrusions. 3. A projection is formed substantially at the center of the inner peripheral surface of the segment body curved in an arc shape in the bending direction, and the inner peripheral surface between one of the joining surfaces of the segment body in the bending direction and the projection. And, on the inner peripheral surface between the other joint surface and the protrusion, the fixing groove of the PC steel material partially crosses the reinforcing bars such as distribution bars and suspension bars embedded in the segment body at a plurality of locations. A PC steel material insertion hole is formed in the portion, and the same number of end grooves as the fixing grooves are formed in the protrusion at a plurality of portions of reinforcing bars such as force distribution bars and suspension bars embedded in the protrusion. A segment formed in such a manner that an insertion hole for a PC steel material is formed in the portion thereof, and an inner end thereof communicates with the fixing groove, and an outer end is opened to an end face of the projection. 4. The segment according to claim 1, wherein a projection is formed substantially at the center of the inner peripheral surface of the segment body in the bending direction. 5. The segment according to claim 1, wherein a corrosion prevention treatment is applied to a reinforcing bar such as a distribution bar or a suspension bar in the insertion hole portion.