JP2001173385A - Tunnel lining segment and its assembling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow to simultaneously introduce prestresses in a peripheral direction of a tunnel lining body and in a tunnel axis direction by makins= easier to assemble segments for tunnel lining by using short-sized PC tensioned members. SOLUTION: Insertion holes for PC tensioned members mutually intersecting in an X-shape near the center of segments 10 in a plan view are arranged within the thickness of a segment slab, a recessed portion 14 for anchoring the PC tensioned member is arranged at its opening, a PC tensioned member 20 equipped with an anchor body at the fixed side and an anchor body at the tensioned side is inserted for each segment or a plurality of segments, and a tension force is introduced while coupling the PC tension member and then the segments are connected in the circumferential direction and axial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel lining used for constructing a communication conduit for a reservoir or the like, a water main, a sewer, a subway, an underground passage, a common ditch for electric / water / communications and other tunnel-like structures. The connection segment is provided for the connection segment.

[0002]

2. Description of the Related Art In recent years, tunnels have been cut in the longitudinal direction,
Furthermore, the curved panel-shaped segment divided in the circumferential direction,
Following the tunnel excavation, a technique of assembling in a tunnel, securing a circular cross section in the ground, filling backfill concrete between the outside of the segment and the excavation ground, and excavating the tunnel is often used. Such a technique is a general technique having many advantages such as the possibility of excavating the entire cross section by an automated excavating machine. Taking advantage of this advantage, this technology is used not only in mountainous areas but also in construction of water supply and sewerage systems in urban areas, subways, underpasses, electricity, gas, or joint tunnels thereof.

[0003] The segments used in such techniques include those made of steel, steel shell concrete, and precast concrete. In addition, various shapes such as a rectangular curved panel and a modified polygonal curved panel are used as the external shape.

[0004] A ring piece formed in a cylindrical shape with such segments must not only secure a cylindrical space but also withstand a bending moment due to an external force acting on a tunnel, for example, earth pressure or water pressure. Further, depending on the application, it is required to resist internal pressure, and water resistance is required. In particular, in the case of a water pipe tunnel, it is desirable that the structure has a structure capable of resisting circumferential tension due to internal pressure.

In order to meet these demands, it has been conventionally proposed to connect the adjacent joint surfaces of the segments by various connection means and connection structures such as a bolt type, a wedge type, a PC cable type or a combination thereof. Bolt-type connection structures and wedge-type connection structures require a large number of bolts and metal fittings in order to obtain a sufficient coupling force, and a segment space is required to secure a work space for attaching and tightening bolts and wedges at the segment joints. It is necessary to provide a notch, a box hole, etc. Accordingly, extra work such as filling the cutouts and box holes with mortar is necessary, which is problematic in terms of cost and workability. In addition, those connected by bolts or metal fittings have a problem that the continuity of force transmission is weak in both the tunnel axial direction and the circumferential direction. The PC cable method requires insertion of a long PC cable, which is not always easy, and the circumferential PC cable has a problem that prestress is reduced by friction.

[0006]

The precast concrete segment can be made thinner, the excavated cross section can be reduced, the excavated soil amount can be minimized, the segment can be easily assembled, and the assembling accuracy can be improved. It has the characteristic that it is high and it is easy to secure resistance strength against external force and water tightness.

The present invention makes it easy to assemble the segments by using as short a PC tendon as possible, which is easy to insert, without using a large number of bolts for connecting such precast concrete segments. To provide a segment having a connection structure capable of simultaneously introducing circumferential and axial prestresses into the inner wall of the tunnel, transmitting the force in the tunnel axial direction continuously, and resisting the internal pressure even in a tunnel where the internal pressure is applied. The purpose is to do. Such a segment can achieve a reduction in construction cost and an improvement in workability. In addition, known tunnel excavators and erectors can be used, and a strong and economical tunnel can be constructed.

[0008]

According to a first aspect of the present invention, there is provided a segment made of precast concrete for tunnel lining which is formed by cutting a cylinder into a plurality of sections and dividing the cylinder in a circumferential direction. In the vicinity of the segment plate, two PC tendon insertion holes, which intersect each other in an X-shape and are inclined with respect to the generatrix direction of the segment, are provided in the segment plate thickness. A tunnel lining segment comprising a PC tendon insertion hole communicating with a segment adjacent in the axial direction and a recess for fixing the PC tendon in each opening.

According to the method of the present invention for assembling a tunnel lining using the segments, a PC tendon having a length corresponding to the insertion length of one or more segments is used.
A fixed-side fixing member and a tension-side fixing member are provided at one end of the PC tendon, and the other end of the PC tendon is inserted into the PC tendon insertion hole to connect with the fixed-side fixing member of the existing PC tendon. A method for assembling a segment for tunnel lining, wherein a force is introduced and the circumferential direction and the axial direction of the segment are sequentially connected by repeating the force.

[0010] In the segment according to a second aspect of the present invention, in the above segment, the two PC tendon material insertion holes are each a pair of parallel insertion holes. Segment. If two PC tension members are inserted into such a pair of parallel insertion holes and are alternately tensioned and fixed, the PC tension members are not connected to the PC tension members of the existing tunnel lining body. The tension of the strut tendons can be continuous.

A second method of the present invention for assembling a tunnel lining by using this segment is to use a segment for tunnel lining having a pair of parallel insertion holes according to the second invention, wherein a plurality of segments are used. A PC tension member having a length corresponding to the insertion length of each piece is used. These PC tension members are provided with a fixed-side fixing member and a tension-side fixing member at both ends, respectively. The material is disposed such that the positions of the fixed-side fixing member and the tension-side fixing member are shifted to different fixing positions for the plurality of segments, and the tension is alternately sequentially introduced to the circumferential direction and the axial direction of the segment. And a method for assembling a segment for tunnel lining. As described above, if the two PC tension members inserted into the respective parallel insertion holes are arranged such that the positions of the fixed-side fixing members and the tension-side fixing members are alternately shifted in the longitudinal direction of the PC tension members, the entirety is obtained. Without connecting the PC tendon,
This is preferable because continuity of tension can be ensured. The lengths of the two parallel PC tendons may not be the same.

A third method invention of the present invention provides a segment ring comprising the segment having the two PC tendon insertion holes crossing in an X shape and the segment having the pair of parallel insertion holes. PC tension members having a length arranged alternately in the tunnel axis direction and inserted through three rows of rings are used, and these PC tension members are provided with a fixed-side fixing member and a tension-side fixing member at both ends, respectively, and are provided for every three rings. A method for assembling a segment for tunnel lining, wherein tension is alternately and sequentially introduced to connect the segments in the circumferential direction and the axial direction. According to this method, the continuity of the tension can be secured by using the segments of the first and second aspects of the present invention to tension every three rings. In this case, the present invention can be particularly suitably applied to the irregularly shaped (substantially cross-shaped) segment that has already been proposed by the present applicant. The fixing section is provided in a segment having a pair of parallel insertion holes. In this case, when assembling a segment having one X-shaped insertion hole, it is preferable to temporarily connect with a bolt or the like to assemble.

Further, the introduction of the tension is performed by a known hydraulic pressure
It may be performed by a method using a jack such as water pressure, but it is preferable to perform the operation using a torque wrench, an impact wrench, or the like because the operation is simplified. This torque wrench or impact wrench may be a commercially available appropriate one such as a manual type, an electric type, and a hydraulic type, and does not need to be special.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a conceptual diagram of a tunnel lining body 50 using the segment connection structure of the present invention. FIG. 1A is a perspective view of a tunnel lining body 50, and FIG. 1B is a front view thereof. The tunnel lining body 50 is formed by connecting a number of ring pieces in which a number of segments 10 are assembled in a ring shape. Each segment 10 has a PC tendon insertion hole that crosses in an X-shape at the center position in plan view, and a number of PC tendon 2 passing through the hole.
0 are integrally connected. The PC tendon has a dual function of interconnecting the segments and introducing prestress. The PC tendons are continuously arranged in a net (net) shape, and are arranged in a multi-spiral shape that is swiveled in both left and right directions as a whole. This embodiment is an example of constructing a tunnel having an inner diameter of 3.0 m. The tunnel section is divided into six in the circumferential direction, and one ring piece is constituted by six segments.
The dimensions of the segment are about 1.6m x 1.2m and the plate thickness is 2
0 cm. In this example, a PC strand was used as a PC tendon.

FIG. 2 shows one segment 10 of the embodiment. FIG. 2 (a) is a plan view, and FIG.
It is an AA arrow front view of (a). The segment 10 is a curved panel obtained by cutting a cylinder into a predetermined length in the axial direction and dividing the cylinder into six in the circumferential direction. Within the plate thickness of the segment 10, an X-shaped PC strand insertion hole 13 intersecting near the center of each segment penetrates, and is arranged so as to communicate between adjacent segments. The opening 15 of the insertion hole 13 is open to a connection recess 14 recessed from the end face 11 of the segment connection surface. The circumferential abutment surface 12 of each segment 10 is provided with a concave ridge 16 and a convex ridge 17 that are fitted to each other, and forms a guide portion so that the segments 10 can be easily assembled.

FIG. 3 is a partially developed view of the tunnel lining body 50. The PC strands 2 which are alternately combined with the segments 10 and penetrate through the X-shaped insertion holes 13 of the respective segments 10
0s are continuously connected and continuous, forming a net (net) shape as a whole. The prestress of each segment 10 is introduced at the tensioned end in the connection recess 14 provided on the end face 11 of the segment 10 in the assembly traveling direction. FIG. 4 shows FIG.
The PC strand 20 inserted into the insertion hole 13 by the sheath is the nut 24
The PC strand 20 connected to the head of the strand fixed by the coupler of the fixing measurement body 31 is connected to the connection recess 14.
It is connected one after another within.

FIG. 5 is a developed view of a part of the tunnel lining body similar to FIG.
It is the figure which was made to connect as a set. FIG. 6 shows C in FIG.
In the detailed view of the part, each segment 10 is inserted into a pair of parallel PC strand insertion holes 13 penetrating in an X shape.
The connection is made alternately for each segment. The fixed-side fixing member 31 used in this method may have a configuration in which the coupler nut described with reference to FIG. 9 is separated.

In the above description, the simplest connection between two adjacent segments has been described. However, one or more segments are arranged between segments having a tensioned end and a fixed end, and three segments are connected. Needless to say, the tension and fixing may be performed between the four pieces.

FIG. 7 is a view for explaining the principle of introducing prestress in the connection structure of the present invention. Segments 10a, 10
When a tension of P is introduced between b and b, a component force is generated by the intersection angle θ, and a ring (circumferential) component force Pr and a cylindrical (tunnel) axial component Pl are generated.
r, a prestress is introduced by the compressive force of the cylindrical (tunnel) axial component Pl. This means that by changing the crossing angle θ, the ring (circumferential) direction prestress,
This shows that it is possible to adjust the introduction amount of the cylindrical (tunnel) axial prestress. Assuming that the tension is P and the intersection angle is θ, when the intersection angle θ = 45 °, Pr = Pl = P · cos θ When the intersection angle θ ≠ 45 °, Pr = P · cos θ and Pl = P · sin θ .

FIG. 8 is a diagram showing the structure of a PC tendon material most suitable for the present invention. The PC strand 20 has a fixed-side fixing member 31 and a tension-side fixing member 21 at both ends thereof. Tension side fixing body 2
Reference numeral 1 denotes a condominium sleeve 25 which is externally fitted to the PC strand 20 and mechanically crimped and has an external thread engraved thereon, a nut 24 which is screwed onto the external thread of the condominium sleeve 25, and a washer 23 which reduces rotational friction of the nut during tension. , And a support plate 22 for transmitting tension. Fixed side fixing body 3
Reference numeral 1 also serves as a coupler for a PC tendon, and includes a sleeve 32 having a tapered hole, a wedge 33 which is fitted in the sleeve 32 and grips the PC strand, and a spring which urges the wedge 33 in a direction of gripping the PC strand 20. 34 and a coupler nut 35. The coupler nut 35 has a male screw that seals the spring 34 in the sleeve 32 and is screwed into the sleeve 32, and also serves as a lid. The male nut of the condominium sleeve 25 of the fixed side fixing body 21 of the preceding PC strand is screwed into the coupler nut 35 to couple with the preceding strand.

The prestress is introduced by manually inserting the PC strand 20 to which the apartment sleeve 25 of the tension side fixing body 21 is crimped from the end face in the tunnel excavation direction of the segment, and fixing the fixing side fixed in advance to the preceding PC strand. The wedge of the body 31 is gripped, and then the support plate 22, the washer 23 and the nut 24 on the tension fixing body side are attached, and the nut 24 is tightened with a torque wrench or an impact wrench. In order to make the rotation of the nut 24 smooth, it is effective to apply anti-friction grease to the washer 23 or to interpose an anti-friction material such as a fluororesin sheet between the nut 24, the washer 23 and the support plate 22. is there. The prestress may be introduced by a known method using a hydraulic jack or the like.

As described with reference to FIG. 6, the fixed-side fixing member 31 shown in FIG.
The figure shows a fixed fixing body that is not connected to the fixing body nut of the preceding PC strand but is separated. In this case, although not shown, the fixed-side fixing member 31 is fixed in the connection recess by a separate means.

FIG. 10 is an explanatory diagram of a technique for causing the fixed-side fixing body 31 to grip the PC strand 20. The fixed side fixing body 31 has a wedge 33 and a spring 34 sealed in a sleeve 32 in advance with a coupler nut 35. Wedge 33
Is divided into two or three in the circumferential direction.
Is fitted to the outer periphery of the sleeve 32 and is fitted into the tapered hole of the sleeve 32 to reduce the diameter, thereby gripping the strand 20. On the inner surface of the wedge 33 that comes into contact with the strand 20, a serrated shape is formed in the circumferential direction so that the wedge 33 securely grips the strand 20.

FIG. 10A shows a step of inserting the PC strand 20 as shown by an arrow 36 toward the fixing body 31 in a state where the diameter thereof is reduced by being urged by the spring 34.
Although not shown, the tip of the strand 20 is connected to the sleeve 3.
Guides are provided to guide the two holes.

FIG. 10B shows a process in which the tip of the strand 20 penetrates into the sleeve 32, pushes the wedge 33 out of the biasing force of the spring 34, and pushes the strand 20.

FIG. 10 (c) shows that when the strand 20 pushed into the innermost part of the sleeve 32 is pulled back by a very small value as shown by an arrow 37, the wedge 33 is advanced by the spring 34 and reduced in diameter to temporarily hold the strand 20. I do. Thereafter, the gripping force of the sleeve 32 increases in accordance with the introduction of the tension, and the fixing can be reliably performed.

FIGS. 11 and 12 are explanatory views of a case where the present invention is applied to a segment 10 of an irregular shape (substantially cross shape) proposed by the present applicant. FIG. 11 is a connection diagram of each segment 10, and an arrow 40 indicates an assembling progress direction. The segments 10 are connected to each other while combining the trapezoidal projections 18 provided on the end faces 11 of the segments 10 in the axial direction of the tunnel, thereby preventing the segments 10 from shifting in the lateral (ring) direction (the direction orthogonal to the direction of the arrow 40). be able to. Further, prestress can be effectively introduced in a direction substantially perpendicular to the slope of the trapezoidal projection 18, which is preferable. FIG. 12 is a development view of the tunnel lining body 50 to which the segment 10 is assembled.

FIG. 13 is a developed view of the lining body showing the construction of the tunnel lining body according to the third method of the present invention. In this example, one ring is formed by five segments, and a segment 10a having one PC tendon insertion hole crossing in an X shape and a segment 10 having two pairs of parallel insertion holes.
b are alternately arranged in the tunnel axis direction, and the PC tendon is fixed every three rings. In FIG.
The face moving direction is indicated by an arrow 40, and the segment ring indicated by a broken line is an imaginary line depicting what is to be constructed next.

FIG. 14 shows the connecting PC strand 2 of the present invention.
PC strand push-in handle 41 suitable for 0 insertion
In this example, a handle 43 is connected to a long nut 42 having a female screw which is screwed into a male screw engraved on an apartment sleeve 25 crimped to the end of the PC strand 20. A long nut 42 is screwed into the condominium sleeve 25 of the PC strand 20, the end of the strand 20 is inserted into the insertion hole of the segment, and guided into the sleeve 32 of the fixed end fixing body 31, as described in FIG. The wedge 33 is expanded and pushed in, and then the PC strand 20 is gripped by the wedge 33 in the sleeve 32 by pulling back the handle 41 by a small amount, and then the handle 41 is removed.
The washer 23 and the nut 24 are attached to the apartment sleeve 25, and the nut 24 is tightened with a torque wrench or the like to connect the segments 10.

In the above embodiment, a description has been given of an example in which the segment is divided into five and six in the circumferential direction. However, the present invention is not limited to this, and the ring is divided according to the required pipe diameter and internal pressure. The number, the size of the segments, the thickness of the concrete wall, and the like are determined, and the segments having optimal dimensions may be designed in consideration of the workability of transportation and assembly.

[0031]

The segment and the method of assembling the segment according to the present invention are formed in a cross section near the center in plan view within the plate thickness of a precast concrete segment obtained by cutting a cylinder into a plurality of pieces and dividing it in the circumferential direction. A PC tendon material insertion hole is provided, and a PC tendon material is inserted by opposing the insertion holes of the adjacent segments in the cylindrical axis direction, and the PC tendon material is fixed to the fixed side alternately every one or more segments. The body and the tension side fixing body are attached and the PC tension member is connected by introducing tension, so it is possible to simultaneously introduce pre-stress in the tunnel axial direction and circumferential direction, and to build a strong tunnel And the effect of improving workability and economic efficiency is great.

[Brief description of the drawings]

1A and 1B are a perspective view and a front view, respectively, showing a tunnel lining body using a segment connection structure of the present invention.

FIG. 2 is a (a) plan view and (b) front view of a segment.

FIG. 3 is a development view of a part of the tunnel lining body.

FIG. 4 is an enlarged view of a portion B in FIG. 3;

FIG. 5 is a development view of a part of another example of a tunnel lining body.

FIG. 6 is an enlarged view of a portion C in FIG. 5;

FIG. 7 is a diagram illustrating the principle of prestress introduction in the connection structure of the present invention.

FIG. 8 is a configuration diagram of a PC tendon according to the embodiment.

FIG. 9 is a configuration diagram of a PC tendon according to the embodiment.

FIG. 10 is an explanatory diagram of a technique in which a fixed-side fixing body grips a PC strand.

FIG. 11 is a connection diagram of segments of another embodiment.

12 is a development view of a tunnel lining body to which the segments shown in FIG. 11 are assembled.

FIG. 13 is a connection diagram of segments according to another embodiment.

FIG. 14 is an explanatory view showing an example of a PC strand pushing handle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 (10a, 10b) Segment 11 End face of connection surface (end face in the assembling direction) 12 Abutment face 13 PC strand insertion hole 14 Depression 15 Opening 16 Concave strip 17 Protrusion 18 Trapezoidal protrusion 20 PC tension member (PC strand) 21 Tension side fixing body 22 Support plate 23 Washer 24 Nut 25 Condominium sleeve 31 Fixed side fixing body 32 Sleeve 33 Wedge 34 Spring 35 Coupler nut 40 Arrow 41 Push-in handle 42 Long nut 43 Handle 50 Tunnel covering body

Claims (6)

[Claims] In a precast concrete segment for tunnel lining divided into a plurality of cylinders in a circumferential direction and divided in a circumferential direction, the segments intersect each other in an X-shape near the center of the segment in plan view, and are arranged in the generatrix direction of the segment. Two PC tendon insertion holes having an inclination are provided in the thickness of the segment plate, and the PC tendon insertion holes are opened at the end faces of the segments and communicate with the adjacent segments in the tunnel axis direction. A tunnel lining segment having a recess for fixing a PC tendon material in each opening. 2. The two PC tendon insertion holes are each a pair of parallel insertion holes.
The tunnel lining segment as described. 3. A fixing member and a tension member on one end of the PC tension member, wherein the PC tension member has a length corresponding to the insertion length of one or more segments. Side fixing member, the other end of the PC tendon is inserted into the PC tendon insertion hole, and is connected to the fixed side fixing member of the existing PC tendon to introduce tension, and this is repeated to sequentially form circles of segments. A method for assembling a segment for tunnel lining, comprising connecting the circumferential direction and the axial direction. 4. The tunnel lining segment according to claim 2, wherein a PC tension member having a length corresponding to the insertion length of each of the plurality of segments is used, and the PC tension members are fixed fixing members at both ends. And two tension members to be inserted into the parallel insertion holes, wherein the arrangement positions of the fixed-side fixing member and the tension-side fixing member are shifted to different fixing positions for the plurality of segments. And a method for assembling a segment for tunnel lining, wherein tension is alternately and sequentially introduced to connect the circumferential direction and the axial direction of the segment. 5. A segment ring comprising segments for tunnel lining according to claim 1 and 2, which are alternately arranged in the tunnel axial direction, and have a length P which is inserted through three rows of rings.
Using a C tension member, the PC tension member has a fixed-side fixing member and a tension-side fixing member at both ends, respectively, and successively introduces tension alternately for every three rings to connect the circumferential direction and the axial direction of the segment. A method for assembling a tunnel lining segment, comprising: 6. The method according to claim 3, wherein the introduction of the tension is performed using an impact wrench or a torque wrench.
6. The method for assembling a segment for tunnel lining according to any one of claims 5 to 5.