JP3167937B2 - Construction method of shield lining segment and shield tunnel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication conduit for a reservoir having a height difference, a water main, a sewer, a subway, and the like.
When constructing a tunnel such as an underpass, or a tunnel-like structure serving as a common groove for electricity, water, gas, etc., the present invention relates to a shield lining segment forming these wall surfaces and a method of constructing a shield tunnel using the same. .

[0002]

2. Description of the Related Art Conventionally, in mountain tunnels such as roads and railways, there has been adopted a technique of assembling a support inside an excavation tunnel as a tunnel lining and winding up a lining with cast-in-place concrete. Techniques for performing lining with precast concrete segments have been adopted. Such a technology produces a curved panel-shaped segment that is divided into a large number in the axial direction and cut into multiple pieces in the axial direction, and then assembled into the inner surface of the tunnel following tunnel excavation. This technology secures a circular cross section, fills backfill concrete between the outside of the assembled panel and the excavation ground, and excavates the tunnel forward. Such a technique has many advantages, such as not requiring a shoring work and enabling full-section excavation by advanced mechanization, and is a general method.
Taking advantage of this advantage, not only in mountains but also in urban water and sewage,
It is used in tunnels such as subways and underpasses, common ditch tunnels such as electricity, gas, and water, and composite tunnels thereof.

[0003] Among them, in a tunnel having a relatively small cross section (about 3.0 mφ or less), a technology for connecting and connecting ring pieces cut in a longitudinal direction to about 1.0 to 2.5 m in a groove cut out from the ground. and, if the digging like urban areas with difficult conditions, the tunnel starting pit provided, to drilling laterally with shield machine from the shafts, following the drilling and pushing promote ring pieces, one after the other on its tail There is a technology to connect the ring piece with the ring and push it in.

However, in a tunnel having a large cross section, it is difficult to manufacture and transport the ring piece and to push it in.
A method is adopted in which the ring piece is further divided into a plurality of segments in the circumferential direction, assembled in a ring shape using an automatic assembler (hereinafter, referred to as an erector) behind the shield excavator, and connected and advanced. The assembly equipment for this segment was fully automated, making it possible to build tunnels very efficiently. The segments used here are made of steel, steel shell concrete, precast concrete, etc., and their shapes are variously modified from simply rectangular curved panels to deformed polygon curved panels. I have.

The ring pieces formed by these segments not only ensure a cylindrical space but also resist external forces acting on the tunnel, for example, earth pressure, bending moment due to differential settlement, and internal pressure depending on the application. And water tightness is required. Conventionally, the connection between segments has been made by sewing adjacent joint surfaces with bolts, connecting metal fittings, PC steel bars, or a combination of them. There is a problem that a notch or a box hole is required to secure space, and extra work such as trace filling is required, and those connected with bolts and metal fittings are both in the tunnel axial direction and circumferential direction. There were problems such as poor continuity of force transmission. In particular, in the case of a communication headrace such as a reservoir having a height difference, a water main, or the like, it is necessary to have a strength capable of resisting circumferential tension due to internal pressure.

[0006]

The problem to be solved by the present invention is as follows. (A) Assembling has a high ratio of accuracy, is easy to assemble, and has a rational shape in which the connecting lines between the segments are not linear, and the segments are engaged with each other so that the wedge effect works. (B) Make the segment members as thin as possible, make the excavated cross section smaller, and minimize the amount of excavated soil. Take measures to ensure resistance to external forces and water tightness. (C) A known shield excavator and erector can be used for assembly, and a tunnel can be constructed safely and reliably.

It is an object of the present invention to provide a shield lining segment that solves the above-mentioned problems, and a method of constructing a shield tunnel using the same.

[0008]

SUMMARY OF THE INVENTION The present invention has been developed to solve the above problems, and comprises the following technical means. That is, the cylindrical shell is divided into many
The shape of the circular arc plate is
With a trapezoidal projection on the end face in the axial direction, and a cylindrical axial direction and a circumferential direction through which the PC tendon is inserted
Of the tunnel is built in the arc plate, and it is tightened in the circumferential direction of the tunnel.
Fix the fixing part of PC steel wire to the protrusion on the end face
Provided is a segment for shield lining, which is made of precast concrete formed on a side surface . The profile of the arc plate is an end face in a direction parallel to the cylindrical axis.
Are inclined with respect to the cylindrical generating line and both end faces are
It is preferable that the protrusions have a shape of a letter C or a parallel shape, and the protrusions have a shape in which end faces perpendicular to the cylindrical axis of adjacent segments are closely meshed with each other, and the substantially cross shape closely forms a cylindrical shell.
If several types of fixed shapes are arranged in a staggered manner so as to form, a strong and watertight tunnel having a tight meshing shape can be constructed with several types of segments .

According to the method of the present invention for constructing a tunnel by using such a segment, when assembling the shield lining segment on the inner surface of the tunnel, the segment for one round to be attached is formed by a PC steel rod in the longitudinal direction of the tunnel. An excellent tunnel can be efficiently constructed by introducing tension into the ring piece formed by the one-turn segment with a PC tension member in the circumferential direction and sequentially repeating the above.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a shield lining tunnel 1 using a segment 2 of the present invention, wherein (a) is a front view and (b) is a perspective view. FIG. 2 is a development view of the shield tunnel of FIG. This example is a shield lining tunnel having an inner diameter of 4.8 m, and the cross section of the tunnel 1 is divided into six in the circumferential direction, and six segments 2 constitute a ring piece of one circumference. The size of the segment 2 is about 2.5 m × 1.2 m, the plate thickness is 18 cm, and the weight of one piece is about 1.1 tons.

The axial PC steel rods 4 are 26 mmφ × 4 per segment, and the circumferential PC tendons 5 are 1T-
Two 21.8 PC steel strands were used per ring. As shown in the developed view of FIG. 2, the shield lining tunnel 1 of the present invention basically has a profile of an arc plate except for the segment 3 of one ring (the uppermost ring in FIG. 2) on the wellhead side. The cross-shaped segments 2 are connected in a ring shape in the circumferential direction, and are continuously provided in a meshing manner in the axial direction. PC steel rod 4 in the axial direction, PC steel stranded wire 5 in the circumferential direction
Are tied up. The axial PC steel bar 4 is used for supporting each segment when assembling and introducing axial prestress. Circumferential direction PC steel wires 5 are arranged two turns per ring, and a tension fixing end is provided on the end face in the traveling direction of the segment (the lower end face in FIG. 2).

The shield lining segment 2 of the present invention is shown in a perspective view in FIG. 3 and a plan view in FIG. 4, in which the profile of the arc plate has a substantially cross shape, and the end faces 21 and 22 in the circumferential direction of the tunnel are formed. It is not parallel to the tunnel axis or the generatrix of the cylinder of the tunnel, but is formed into a wedge shape with a certain inclination angle, and at the same time, the end surfaces 21 and 22 are surfaces extending along the radial direction of the tunnel. , Ridge 2
4 are provided. The shape of the circumferential end faces 21 and 22 makes it easy to assemble the final segment of the ring piece in one round, as if pushing a taper cotter. Further, trapezoidal projections 31 and 32 are provided on the end surface of the segment 2 in the tunnel axis direction. As is apparent from the developed view of FIG. 2, the segments 2 are arranged in a zigzag pattern on the cylindrical surface, and the projections 31 and 32 are engaged with the projections of the adjacent segments so as to firmly adhere to each other.

Segment 2 includes a PC in the tunnel axial direction.
A sheath 25a for a steel rod is built in, and a fixing unit 25 is provided. A sheath 26 through which a PC steel wire is inserted is buried in the circumferential direction of the tunnel, and its fixing portion 27 is formed on the side surface of the projection 32 on the end face in the traveling direction of the segment. The segment 2 is manufactured at a factory or the like in a divided shape and size in consideration of portability, and is carried on site to be assembled.

In the construction of the tunnel, the shield lining segment of the present invention is assembled using an erector connected to a shield excavator. Known shield excavators and erectors are used. First, as shown in the development view shown in FIG. 2, the wellhead segment 3 is installed at a predetermined interval from the center line A of the tunnel bottom, and the segments are alternately arranged toward the tunnel ceiling line B by sandwiching a thin rubber plate on each end surface. Assembling, first, the wellhead side first ring is assembled, and based on this, the segment 2 of the present invention is sequentially assembled as the excavation progresses.

FIG. 5 is a diagram for explaining the incorporation of the segments according to the embodiment. The new segment 42 is attached to the existing segment 41 while connecting the PC steel bar, and the wedge-shaped segment 43 is inserted at the end of one round. It is accurately combined with the concave and convex strips of the guide on the side of the segment and the effect of the cutting line perpendicular to the circular tangent. Two rounds of PC stranded wire are inserted from the fixing end of the circumferential cable, and the fixing portion 27 (see FIGS.
Tension and anchoring of steel strands, introducing circumferential prestress.

Subsequently, a second ring segment is installed in accordance with the concave portion of the segment of the first ring. At this time,
The PC steel bars at the end faces of the respective segments of the first ring and the PC steel bars inserted through the second ring segment are sequentially assembled while being connected by a coupler. When the final segment covering the tunnel ceiling line B is assembled in the same manner as in the first ring by the method shown in FIG. 5, the assembly can be easily performed. Also,
A thin rubber plate is also sandwiched between the first ring and the second ring joining surfaces to make the water blocking effect and the mutual familiarity of the segments. Once the ring is completed, insert the circumferential PC steel wire and tighten it.
Inject grout. In addition, grouting is carried out after collecting several rings. 6 (a), 6 (b) and 6 (c) show the profile of the basic shape.

Thereafter, the same operation is repeated over the entire length of the tunnel. It is conventional to fill the gap between the outer peripheral surface of the ring piece and the excavation ground with mortar or concrete. In this example, the standard diameter is used as an example.However, according to the required diameter and the pipe corresponding to the external force, the number of ring divisions, the size of the segments, and the thickness of the concrete wall will improve the workability of transportation and assembly. It is possible to design with an optimum one in consideration of the above.

[0018]

The shield lining segment of the present invention is
The profile of the arc plate is roughly in the shape of a cross, and several types of segments can be connected to form a strong shield tunnel.The structural strength is achieved by introducing prestress in both the axial and circumferential directions. In this way, the tension material can be fixed at the end face, and an excellent shield tunnel with a flat surface without unevenness can be constructed without secondary lining.

[Brief description of the drawings]

FIG. 1A is a front view and FIG. 1B is a perspective view of a shield tunnel using a segment according to an embodiment.

FIG. 2 is a development view showing an arrangement of segments of a shield tunnel using the segments of the embodiment.

FIG. 3 is a perspective view of a segment of the embodiment.

FIG. 4 is a plan view of a segment of the embodiment.

FIG. 5 is an explanatory view showing a method of attaching a segment.

FIG. 6 is a plan view showing a basic shape of a segment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tunnel 2 segment 3 segment 4 PC steel rod 5 PC steel strand 21, 22 End surface 23 Concave streak 24 Convex streak 25 Fixing part 26 Sheath 27 Fixing part 31, 32 Projection 33 Coupler 41, 42, 43 segment

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E21D 11/08 E21D 11/04

Claims (4)

(57) [Claims] 1. An arc-shaped plate formed by dividing a cylindrical shell into a large number of parts, and the profile of the arc-shaped plate is an end in a tunnel axial direction.
PC with trapezoidal projection on the surface
The sheath in the cylindrical and circumferential directions through which the tendon is inserted is circular.
Built in the arc plate to set the PC steel wire tightened in the circumferential direction of the tunnel
The attachment part is formed on the side of the protrusion on the
A shield lining segment made of precast concrete. Wherein profiles of said arcuate plate includes an end face in a direction parallel to the cylinder axis inclined relative to the generatrix of the cylindrical and end surfaces forms the shape or parallel form of the slanted roof each other, the projection < 3. The shield lining segment according to claim 1, wherein the end surfaces of the adjacent segments perpendicular to the cylindrical axis are closely meshed with each other. 3. The shield lining segment according to claim 1, wherein said substantially cross shape is a plurality of fixed shapes staggered so as to form a cylindrical shell densely. 4. A segment for shield lining according to claim 1.
Should be installed when assembling the tunnel inside the tunnel
One round segment is made of PC steel bar in the longitudinal direction of the tunnel.
Tie to the existing segment, forming a segment for one round
Tension is introduced to the ring piece by using a PC tension member in the circumferential direction
Shield ton, characterized by repeating the above sequentially
How to build a flannel.