JPS6032239Y2 - Joint structure of concrete segment for tunnel lining - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a joint structure of concrete segments for lining tunnels in underground sewers, underground railways, etc., for example.

Each concrete segment of a tunnel lined using the shield method etc. (hereinafter referred to as a segment).

), the tunnel direction and circumferential direction of the segments are most often joined by various joint fittings, and various joint structures have been developed.

By the way, stress due to earth pressure and the like acting on the constructed segments tends to concentrate at the joints between the segments, and in particular, the stress concentrated at the joints of the segments in the tunnel direction is extremely large.

For example, if the excavation direction is bent during lining using the shield method, unreasonable compressive and tensile loads will occur in the tunnel direction, that is, in the width direction of the segments, and as a result, the joints of the segments in the tunnel direction will become important. .

Conventionally, as joint structures for concrete segments for tunnel lining, the following joint structures have generally been developed.

One method is to bury joint fittings that abut each other at the tunnel-direction joint ends and circumferential joint ends of the segments while reinforcing them with reinforcing steel bars, and then connect the joint fittings with bolts to join the segments.

However, with this method, if tensile force is generated at the joint between segments, cracks will occur in the concrete near the joint fittings, which will eventually cause the joint fittings to come off or locally break, making it impossible to ensure sufficient support strength for the tunnel. .

In addition, three or four fittings are buried in contact with each other at the joints, and each fitting is bolted one by one, making the work cumbersome and lacking in speed.

- Another method is to connect a plurality of segments at the same time by continuously passing a PC steel wire through the thickness of the segment in the tunnel direction and applying tension to the PC steel wire.

However, this requires installing a large number of segments at predetermined positions so that the PC steel wire through holes formed in the thickness of the segments communicate with each other, which is a very troublesome work in civil engineering work that tends to be rough. be.

Furthermore, since a large number of segments are joined at once, it cannot be said that the joining between adjacent segments in the tunnel direction is necessarily reliable.

This invention was developed in view of the above-mentioned circumstances, and half of the bolt is passed through a bolt through hole that passes through one segment in the tunnel direction, and the other half of the bolt is passed through the bolt hole between adjacent segments in the tunnel direction. The segments adjacent in the tunnel direction are passed through a recess opening inward of the tunnel at the joint between circumferentially adjacent segments, and a nut that presses the joint end surface of the segment is screwed onto the end of the bolt. The object of the present invention is to provide a joint structure for tunnel lining segments, which allows the connection work to be easily and quickly performed during construction by joining the segments, and also ensures reliable connection between the segments.

This invention will be explained below with reference to illustrated embodiments.

In the figure, reference numeral 1 denotes a concrete segment for tunnel lining, which is arranged in a staggered manner in the tunnel direction so that the joints in the tunnel direction are so-called broken joints that are different for each step in the circumferential direction of the tunnel.

Bolt through holes 2 are formed approximately in the center of the concrete segment 1 and correspond to joints in the tunnel direction of concrete segments 1 and 1 adjacent to each other in the tunnel direction. A recess 3.3 having an inner diameter slightly larger than the inner diameter of the bolt through hole 2 is formed at each open end.

A sheath 4 is inserted into the bolt through hole 2, and a recess 3
A reinforcing iron plate 5 is attached to the bottom of , 3.

At the joint of the concrete segments 1, 1 in the tunnel direction, that is, at the joint between the concrete segments 1, 1 adjacent in the circumferential direction of the tunnel, there is a concrete segment 1 that opens inward of the tunnel and is adjacent in the tunnel direction.
A groove 6 communicating with the bolt through hole 2 is formed continuously in the width direction of the concrete segment 1.

The groove 6 is formed by cutting out a part of the inner corner of the end surface of the tunnel in the circumferential direction of the concrete segment 1 so as to have a cross section of approximately 1/4 arc, and by abutting this notch, the groove has a substantially U-shaped cross section that opens inward of the tunnel. It is formed.

Concave portions 7, 7 having an inner diameter slightly larger than the inner diameter of the concave groove 6 are formed at the opening end face of the concave groove 6 in the tunnel direction.

Furthermore, reinforcing iron plates 5 are attached to the bottoms of the grooves 6 and the bottoms of the recesses 7, 7.

A connecting bolt 8 is disposed between adjacent concrete segments 11 in the tunnel direction, with half of the connecting bolt 8 passing through the bolt through hole 2, and the other half of the connecting bolt 8 passing through the groove 6, and at the end of the connecting bolt 8. Nuts 9 that press the bottoms of recesses 3 and 7, respectively, are screwed through washers 10 to connect concrete segments 1 and 1 adjacent to each other in the tunnel direction.
are joined.

The connecting bolts 8 are arranged in a staggered manner in the circumferential direction of the tunnel so that the end portions of the connecting bolts 8 are hardened differently for each step in the tunnel direction.

Further, the space between the connecting bolt 8 and the bolt through hole 2 is filled with grout 11, the space between the connecting bolt 8 and the groove 6, the recess 3, and the recess 7 are filled with mortar 12,
The concrete segments 1, 1 and the connecting bolts 8 are integrated.

Normally, this joint structure alone is sufficient to connect the concrete segments 1 and 1 in the tunnel direction and the circumferential direction of the tunnel, but in order to make the connection between the concrete segments 1 and 1 more reliable, A conventional joint structure in which the joint fittings that abut each other at the joint end in the tunnel direction and the joint end in the circumferential direction of the concrete segments 1, 1 are buried while being reinforced with reinforcing iron plates, and the joint fittings are connected by bolting. It is also possible to use them together.

This invention consists of the above-mentioned structure, and the following effects can be expected.

■ During construction, adjacent concrete segments are connected by connecting bolts that pass through the concrete segments in the direction of the tunnel, and nuts that are screwed onto the connecting bolts and press the joint end faces of the concrete segments, so the concrete segments can be easily and quickly connected. You can perform the connection work between the two.

■Half of the connecting bolt passes through the bolt through hole of one concrete segment between adjacent concrete segments in the tunnel direction, and the other half opens inside the tunnel at the joint in the tunnel direction of the adjacent concrete segments in the tunnel direction. Because they are arranged through the groove, even if the concrete segments adjacent in the tunnel direction shift in the circumferential direction of the tunnel or outward from the tunnel during construction, and if there is a shift between the bolt through hole and the groove, the joint will not be damaged. It can be corrected with.

■ Even if stress is concentrated toward the inside of the tunnel at the joint between adjacent concrete segments in the tunnel direction, it is resisted by the compressive force of the concrete segments and the tensile force of the connecting bolts, so it has excellent strength.

■ The coupler nut is used to tighten the steel rod against the shear force acting on the segment ring in the direction perpendicular to the tunnel axis, and the receiver has this, increasing safety.

[Brief Description of the Drawings] Figures 1 to 4 show examples of this invention.
Fig. 1 is a plan view from inside the tunnel showing the joint state between concrete segments for tunnel lining, Fig. 2 is an enlarged side view of the joint in Fig. 1, and Fig. 3 is A--A in Fig. 1. A-line enlarged sectional view, Figure 4 is B- in Figure 1.
It is a sectional view taken along the B line. 1... Concrete segment, 2... Bolt through hole, 3... Recess, 4... Sheath, 5... Reinforcement steel plate, 6... ... Concave groove, 7.
...Recessed portion, 8...Connection bolt, 9...
...Natsuto, 10...Washer, 11...
- Grout, 12...Mortar.

Claims (1)

[Scope of utility model registration request] This is a joint structure between adjacent concrete segments in the tunnel direction of concrete segments for tunnel lining arranged in a staggered manner in the tunnel direction, and half of the bolts are inserted between the concrete segments adjacent in the tunnel direction on one side in the tunnel direction. At the same time, the remaining half of the bolt is passed through a concave groove opening inward to the destination tunnel in the tunnel direction of a concrete segment adjacent in the tunnel direction, and the end of the bolt is inserted into the concrete segment. A joint structure for concrete segments for tunnel lining, characterized in that the joint is joined by screwing a nut that presses the joint end face of the concrete segment.