JPH0452320Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention relates to water-stop grooves in segments, and more specifically, to corners of water-stop grooves formed on the outer periphery contact surfaces of a plurality of segments constituting a prefabricated tunnel. This concerns the structure of the department.

[Prior art]

In the shield construction method conventionally used in prefabricated tunnel construction, a water-stop sealing material is attached to the joints of a plurality of segments that make up the prefabricated tunnel.

That is, FIGS. 4 to 8 a, b, and c show a prefabricated tunnel W equipped with the conventional segment sealing material 1.
A perspective view of , and its assembly components are shown, respectively. 2 is a segment formed in an arc shape (see Figure 7), 3 is a joint part of segment 2, and 4 is a connection provided in joint part 3. The bolt hole for the segment sealing material 1 (see Fig. 6)
is attached to the entire circumference of the outer peripheral side of the segment 2.

Further, 5 is a water stop groove formed on the outer circumferential side of the segment 2, 6 is an inter-piece joint portion that joins the arc-shaped segments 2 together to form a ring shape, and 7
2 shows an inter-ring joint portion where segments 2 are joined to form a ring shape.

In the inter-ring joint portion 7, as shown in FIG. 4, there is a portion A where the corner portion of the segment sealing material 1 and the straight portion contact in a T-shape,
At this abutting portion A, a pressing force is applied in the direction of the arrows X and Y by the connecting bolt.

By the way, in the conventional segment sealing material 1, since the cross-sectional shape of the corner ridge line portion Q is formed with an angular shape such as a right angle, each corner ridge line portion Q is
When gathered together in a T-shape as shown in Figures a and b or in a cross-shape as shown in Figure 8c and tightened together with bolts, etc., each ridgeline portion Q abuts against each other and the adjacent segment seals There was a problem in that the material 1 was stuck into the material 1 and a void 8 was created.

In order to solve this problem, conventionally, as disclosed in Japanese Utility Model Application Publication No. 55-71797, corner ridges are gathered together in a T-shape or a cross shape, and complex and uneven compressive stress is generated. A segment sealing material has been proposed in which the cross-sectional shape of the corner ridgeline portion is formed into a substantially arcuate shape so that no voids are formed even when the sealing material acts.

However, even with such conventional segment sealing materials, it is difficult to completely eliminate the voids at the corner ridges where the segments are gathered together in a T-shape or cross shape, and some voids do occur. but,
When using prefabricated tunnels in tunnels where water pressure is not so great, it is possible to ensure watertightness with conventional segment sealing materials, but for example, undersea tunnels with 5Kg/cm ²
When carrying out in a place where water pressure is higher than
It is very difficult to ensure watertightness.

Also, if the segment opening is large,
There was a problem in that the segment sealing material did not adhere well to the corner ridge, and the contact pressure decreased, resulting in a significant decrease in sealing performance.

On the other hand, if the opening of the segments is extremely small, problems such as segment breakage may occur due to a local increase in the contact pressure of the segment sealing material at the corner ridgeline.

Further, the cross-sectional area perpendicular to the longitudinal direction of the conventional segment sealing material 1 is set to be equal to or smaller than the cross-sectional area perpendicular to the longitudinal direction of the water stop groove 5 .

Therefore, the volume of the segment seal material 1 per unit length can be set to be less than the volume of the water stop groove 5, and overcompression of the segment seal material 1 can be prevented. The volume of 1 is greater than the volume of the water stop groove 5,
When assembling the segments, the reaction force of the segment sealing material 1 at the corner portions becomes large, which causes the corner portions of the segments to be damaged, especially in the case of segments made of reinforced concrete.

[Purpose of invention]

This invention was devised by focusing on such conventional problems, and its purpose is to reduce the concentration of compressive stress in the segment sealing material at the corner part when assembling the segments. It effectively prevents breakage of the segment corners due to excessive compression reaction force of the sealing material body, and also prevents poor adhesion of the sealing material body at the corner ridgeline and lower contact surface pressure as the opening amount of the segments increases. The present invention provides a water stop groove of a segment that can suppress water, ensure watertightness, and significantly improve sealing performance.

[Structure of the idea]

In order to achieve the above object, this invention forms water-stop grooves with a concave cross-section on the outer periphery abutting surfaces of the plurality of segments that make up the prefabricated tunnel, and each water-stop groove is filled with a band-shaped groove made of rubber-like elastic material. The volume of the water stop groove of each segment to which the sealing material body is attached is configured to gradually increase toward the corner portion, and the shape allows the volume of the corner portion of the sealing material body to be accommodated when the segments are connected to each other. By configuring this, it is possible to alleviate the concentration of compressive stress in the segment sealing material at the corner part when assembling the segment, and effectively prevent damage to the corner part of the segment due to excessive compressive reaction force of the sealing material body. The gist of this is that

[Example of idea]

Embodiments of this invention will be described below based on the accompanying drawings.

In the following description, the same components as those of the above-mentioned conventional example will be described with the same reference numerals.

Figure 1 shows the main body of the sealing material 1 in which this idea was implemented.
1 attached to the water stop groove 5 of segment 2,
Figure 2 is a side view of Figure 1, Figure 3 is a - side view of Figure 1.
The sealing material main body 11, which is shown in a sectional view taken in the direction of arrows and formed into a band shape from the vulcanized rubber material, is installed in a water stop groove 5 formed on the outer peripheral side surface of the segment 2.

The water stop groove 5a in the corner part 2a of the segment 2 is formed in the corner part 2a as shown in FIG.
It is formed in a tapered shape so that the volume of the area perpendicular to the longitudinal direction gradually increases toward the end, and is configured in a shape that can accommodate the volume of the corner portion 11a of the sealing material body 11 when the segments are connected to each other.

That is, by setting the length L of the water stop groove 5a in the corner portion 2a to at least five times the width H of the sealing material main body 11 from the corner end, the volume of the water stop groove 5a can be reduced by the sealing material. The volume of the main body 11 is set to be larger than that of the corner part 1 when assembling the segments.
The corner portion 2a of the segment 2 is arranged so that the sealing material body 11 of the segment 1a can be accommodated inside the water stop groove 5a.
The compressive stress concentration on the sealing material main body 11 can be alleviated, and breakage of the corner portions 2a of the segments 2 due to excessive compressive reaction force of the sealing material main body 11 can be effectively prevented.

[Effect of idea]

As mentioned above, this invention is configured so that the volume of the water stop groove of the segment gradually increases toward the corner part, and when the segments are connected to each other, the volume of the corner part of the sealing material main body is shaped so that it can be accommodated. With this structure, it is possible to alleviate the concentration of compressive stress on the sealing material main body at the corner part when assembling the segments, and therefore, it is possible to prevent overcompression that would cause plastic deformation of the sealing material main body, and damage to the sealing material main body can be prevented. This has the effect of preventing water leakage, ensuring a predetermined contact pressure over a long period of time, and maintaining water-stop properties. At the same time, it is possible to prevent damage to the segment corners due to excessive compression reaction force of the sealing material body, and even when the segment opening amount is 0, the sealing material body is compressively deformed and completely fits into the water stop groove. This has the effect of effectively preventing a decrease in strength of the joint due to poor adhesion of the segment joint.

[Brief explanation of the drawing]

Fig. 1 is an enlarged front view of a corner of a segment in which this invention has been implemented, Fig. 2 is a side view of Fig. 1, Fig. 3 is a sectional view taken along the - arrow in Fig. 1, and Figs.
Figures a, b, and c are explanatory diagrams and seal structures of each component constituting a conventional prefabricated tunnel.
The figures are a perspective view of a conventional prefabricated tunnel, Fig. 5 is a partial sectional view of a segment, Fig. 6 is a perspective view of the sealing material body, Fig. 7 is a perspective view of a segment, and Fig. 8a
- FIG. 8c is an explanatory diagram showing a state in which segment sealing materials are gathered together. 2... Segment, 2a... Corner portion of segment, 5... Water stop groove, 11... Seal material body.

Claims (1)

[Scope of utility model registration request] A segment consisting of a plurality of segments constituting a prefabricated tunnel, in which a water stop groove with a concave cross section is formed on the outer peripheral contact surface, and a band-shaped sealing material body made of a rubber-like elastic material is attached to each of the water stop grooves. In the water cutoff groove of the segment, the volume of the water cutoff groove of the segment is configured to gradually increase toward the corner portion, and the water cutoff groove of the segment is configured to have a shape that can accommodate the volume of the corner portion of the sealing material body when the segments are connected to each other. A segment water stop groove characterized by: