JPS5913640B2 - concrete segment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to concrete segments for lining tunnels in underground sewers, underground railways, etc. (each concrete segment of a tunnel lined by the shield method etc. Most of them are connected, and there are various types of joint fittings.

By the way, stress due to earth pressure, etc. on constructed segments tends to concentrate at the joints between the segments, and the mode of action of that stress is also various.

Furthermore, if the excavation direction is bent during lining using the shield method, unreasonable compressive and tensile loads will be applied in the tunnel direction, that is, in the width direction of the segment, and the tensile load has a large effect on the joint fittings.

If the tensile load is large, 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.

Therefore, it is important to ensure sufficient strength for the middle joint fittings as well as for the circumferential joint fittings.

This invention was devised in view of the above circumstances, and proposes a concrete segment that can be easily manufactured and has a joint fitting that is fixed with high strength.

Hereinafter, the present invention will be explained by means of illustrative embodiments.
As shown in Fig. 2, the concrete segment 1 consists of a concrete member 2 made of a precast plate curved in an arc shape with a curvature corresponding to the tunnel diameter, and a widthwise joint fitting 3 provided at the peripheral joint end. and a circumferential joint fitting 3 and a circumferential joint fitting 4.

A plurality of recessed notches 5 are provided at the peripheral joint end on the inner circumferential surface side of the concrete member 2, which are opened at the opening on the joint end surface side, and the joint fittings 3, 4 are placed flush with the end surface.
8, and a bolt fastening gap 6 is secured at the back of the joint fittings 3 and 4. Note that when the segment 1 is joined to the inner circumferential side edge of the concrete member 2, the adjacent A continuous notch is provided so that a groove 12 for filling the joint material is formed between the joint ends, and the widthwise and circumferential joint fittings 3 and 4 are made of cast iron, preferably ductile cast iron. This makes it easy to manufacture the fittings.

That is, when ordinary steel is used as in the past, a large machine such as a press is required, but cast iron can be easily formed into any shape by mold forming.

The widthwise joint fitting 3 is formed to have a circular cross-section, and has a bolt insertion hole 7 bored in the center (also has a pair of left and right flanges on the sides that are bent toward the outside of the sides). 8 is formed to be firmly buried in the concrete member, and the threaded part of the approximately U-shaped anchor member 9 (specifically, a reinforcing bar, etc.) is inserted into the insertion hole drilled in the flange part. It is fastened and fixed with a nut.

In particular, the present invention utilizes the threaded portion of the anchor member to attach the reinforcing anchor sub member 10 so as to protrude in the distal direction of the flange portion 8 of the joint metal fitting 3, thereby causing tension acting on the joint metal fitting 3. Sufficient strength shall be ensured to withstand the load.

There are various ways of fixing the anchor sub-member 10, as shown in Fig. 3a,
In b, the anchor sub member 10 is wound around the fastening nand of the anchor member 9 and fixed by welding.

In this case, two anchor sub-members 10 are attached to the front and rear surfaces of the flange portion 8.

Two anchor sub-members 10 in FIG. 4 are attached to the front and rear surfaces of the flange portion 8, and the anchor sub-member 10A on the front side is bent rearward.

In FIG. 5, the anchor sub-member 10B on one flange portion 8 side is bent diagonally backward.

FIG. 6 shows an example in which the anchor sub-members 10 on both sides are bent diagonally backward.

In FIGS. 7 and 8, only one anchor sub member 10 is used, and the difference is that it is attached only to the front side or only to the rear side.

Furthermore, as shown in FIGS. 2 and 9, the circumferential joint fitting 4 has the same structure as the width direction joint fitting, but the circumferential joint fitting 4 has a reinforcing backing member on its flange. No. 11 flanges are brought into contact with each other, and the threaded portion of the anchor member is inserted into the insertion hole of both flanges and fastened with a nut to fix the joint fitting, the backing member, and the anchor member as one body.

Further, if necessary, an anchor auxiliary member may be attached to the side flange of the circumferential joint fitting 4 in the same manner as in the case of the widthwise joint fitting 3.

When joining the segments 1, the joint fittings 4 and 3 in the circumferential direction and the width direction are respectively opposed to each other, and connecting bolts are inserted into both bolt insertion holes and fastened with nuts.

This invention has the above-mentioned configuration, and the flange portions of both the widthwise joint metal fitting and the circumferential joint metal fitting are deeply buried in the concrete member, and the flange portion and the main steel member are connected by the anchor member. It can withstand the tensile load that acts between the segments with high strength, and each segment can be rigidly joined, which is advantageous when lining tunnels using the shield method. When inserting the threaded part of the member, the secondary anchor member can also be tightened with a nut, so
Installation of anchors and anchor sub-members is easy;
It is possible to increase the resistance against tensile loads due to the cooperative action of the flange part and the secondary anchor member, and the installation of the joint fittings can be further strengthened by connecting and fixing the anchor member to the main steel frame part. It is.

Furthermore, by attaching a reinforcing backing member to the back of the circumferential joint fitting, the strength of the fitting itself can be strengthened, and if the backing member is buried with an appropriate amount of cover, it is effective as an anchor member. .

[Brief explanation of drawings]

Figure 1 is a half-sectional front view showing the structure of a concrete segment, Figure 2 is a half-sectional plan view thereof, and Figures a and b are [4
A plan view and a front view showing the connection state between the J-direction metal fitting and the anchor sub-member, and FIGS. 4 to 8 are plane views showing other embodiments in which the connection state between the width direction joint fitting and the anchor sub-member is different. FIG. 9 is a perspective view showing a state in which the circumferential joint fitting and the anchor member are connected. 1... Concrete segment, 2...
・Concrete member, J direction joint fitting for 3...
4... Circumferential joint fitting, 5... Concave notch, 6... Gap, 7... Bolt insertion hole, 8...・Flange part, 9...Anchor part, 10...Anchor sub-part, 11...
... Back member, 12... Concave groove.

Claims (1)

[Claims] 1 A plurality of concave notches are provided at the peripheral joint end on the inner circumferential surface side of a concrete member curved in an arc shape, and the cross section is formed into a substantially U-shape at the opening on the joint end surface side of the concave notch, and the central part is formed. The joint fitting has a bolt insertion hole drilled in it and a pair of left and right flanges that are bent outward on the sides thereof.
The flange part is embedded in the concrete member and installed so that the center part is flush with the joint end surface, and the widthwise joint fitting located at the widthwise end surface of the joint fitting has an anchor member inserted into the insertion hole drilled in the flange part. At the same time, the reinforcing anchor sub member protruding toward the distal end of the flange portion is installed and fixed by this threaded portion, and the circumferential joint fitting located on the circumferential end surface of the joint fitting has its flange attached. The flange of the back member is brought into contact with the flange of the back member, and the threaded part of the anchor member is inserted into the insertion hole drilled in both flanges, and the joint fitting, the back member, and the anchor member are screwed together and fixed. A concrete segment characterized by: