JP2002227594A - Fireproof joint structure between segments for shield tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fireproof joint structure for a shield tunnel by means of a segment with a tenon preventing the deterioration of an object provided between inclusions such as a seal material and a share strip when a concrete surface reaches a temperature of 380 deg.C which is a criterion of an immersed tunnel in the Netherlands. SOLUTION: Heat-resistant ventilation shut-off materials 11 are provided at positions where join faces 1a, 1b approach side fringe parts on inner faces of the segments between the join faces 1a and 1b around the segments 1. The ventilation shut-off material 11 is provided by forming a groove 10 for fitting the ventilation shut-off material in the arrangement in which the segments to be joined mutually oppose mutually between them at the positions where the join faces around he segments approach the side fringe parts on the inner faces of the segments and fitting the heat- resistant ventilation shut-off materials 11 in the grooves, respectively, to seal the join faces or by providing recessed parts for caulking in the side fringe parts on the inner faces of the segments of the join faces around the segments and filling a caulking material into a cavity for caulking formed by the recessed parts opposing mutually between the segments to be joined mutually.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refractory joint between segments of a shield tunnel.

[0002]

2. Description of the Related Art In general, moisture inside a concrete evaporates due to a rise in temperature, and a water vapor pressure is generated in the concrete. When the vapor pressure rises slowly, it gradually escapes from the fine pores of the concrete, but when it suddenly occurs due to a fire or the like, it does not escape instantaneously, causing a spalling phenomenon. Peeling occurs. In the Euro Tunnel fire that occurred in November 1996, this explosion caused a segment thickness of 4
Two-thirds of the 0 cm was severely damaged by destruction and peeling.

[0003] When reinforced concrete is heated to a high temperature, mechanical properties such as strength and static elastic modulus are reduced, and furthermore, the adhesive force between the reinforcing steel and concrete is reduced due to a difference in thermal expansion coefficient between the reinforced concrete and the concrete. .

[0004] Since the concrete segment used for the lining of the shield tunnel is made of reinforced concrete, the above phenomenon is caused by heating, and the segment is seriously damaged by heating in a fire accident.

For this reason, as a measure against fire resistance of shield tunnels, generally, as shown in FIG. 7, a fire-resistant insulation board 3 or the like is installed on the inner surface of a lining 2 made of concrete segments 1, 1,. (1000 ° C or higher) to protect the segment.

Because of the need to limit the rise in concrete temperature and to prevent explosion phenomena and loss of mechanical properties, this fire-resistant board has been used in submerged tunnels in the Netherlands.
"Do not exceed 380 ° C on concrete surface"
Performance that satisfies the condition of “not exceeding 250 ° C. on the reinforcing bar surface (cover 25 mm)” is required.

[0007] On the other hand, a shield method using a tenoned segment is a method developed in recent years. This method is
As shown in FIG. 9, a tenon 4a and a tenon groove 4b into which the tenon 4a is fitted are formed on the joining surfaces 1a and 1b between the segment rings 2a assembled in a circular ring shape by the segments 1 when the lining is extended each time the digging is performed. As shown in FIG. 8, by displacing the positions of the circumferential joining surfaces 1c and 1d of the segments 1 between the adjacent segment rings 1a and 1a, a cylindrical shape is held between the segment rings. It is like that.

In this method, the bolts 5 between the segments 1 and 1 are used only for temporary fixing at the time of assembly, and are not included in the strength member.

Further, as shown in FIGS. 9 to 11, the method using the tenoned segment has no steel material that generates rust on the strength member that comes into contact with the air, and has high smoothness on the inner surface of the segment. The secondary lining inside the lining by the segment can be omitted, and between the joining surfaces between the rings, the shear force generated between the rings acts as a transmission material that acts between the tenon and tenon groove between the rings. A shear strip 7 serving as a part and a transmission strip 8 for evenly distributing the jack thrust during shield excavation on the tenon surface are interposed.

Among these inclusions, the sealing material 6 for water stoppage and the shear strip 7 are made of an elastic rubber material, and are transformed at about 120 ° C. to 160 ° C.

On the other hand, in a joint between ordinary segments in which flat joint surfaces having no tenon are joined to each other to assemble a lining, as shown in FIG. Sealing materials 6a, 6a, 6b, 6
There is a joint between the segments of the structure where b is installed twice,
Rubber material is used for sealing material for water stoppage.
Transforms at about 160 ° C.

[0012]

The shield tunnel using the mortise segment or the non-mortise ordinary segment described above has a lining because the joint has a gap even if the fireproof insulation board under the above conditions is installed. When the temperature of the concrete surface on the inner surface reaches 380 ° C, which is the standard for buried tunnels in the Netherlands, the sealing material for waterproofing, especially on the inner surface side of the lining with ordinary segments, and the waterproofing material with the tenoned segments, The sealing material and the shear strip are exposed to this temperature, and there is a problem that melting and deterioration are unavoidable.

In view of such a conventional problem, the present invention provides:
It is an object of the present invention to provide a refractory joint between segments of a shield tunnel in which inclusions such as sealing materials and shear strips do not deteriorate when the concrete surface reaches 380 ° C.

[0014]

SUMMARY OF THE INVENTION The features of the present invention for solving the conventional problems as described above and achieving the intended purpose are as follows.
A joint between each segment when extending a shield tunnel lining by connecting a plurality of segments into a circular ring in a digging direction in a digging direction, and a segment inner surface between joint surfaces around each of the segments. That is, a heat-resistant ventilation blocking material is interposed at a position close to the side edge.

A groove for fitting a ventilation blocking material is formed at a position close to the edge of the joining surface around the segment on the inner surface side of the segment so as to face each other between the segments joined to each other. Inserting a heat-resistant ventilation blocking material into the concave grooves to seal between the joint surfaces, and
A concave portion for caulking is provided on the inner surface side edge of the joining surface around the segment, and a ventilation blocking material made of a caulking material is provided in a caulking space formed by the concave portions facing each other between the segments joined to each other. Filling is preferred.

According to the present invention, the segment is a tenon segment in which a tenon and a tenon groove formed on a joint surface of each segment with a lining ring are fitted and joined to each other,
This is more effective when applied to a joint formed by interposing a shear strip between a tenon and a tenon groove that are fitted to each other, but in addition, the segment is a normal segment connected with a flat joint surface. In addition, it is effective to apply the present invention to a joint in which a sealing material for waterproofing is interposed twice between the joining surfaces of the ordinary segments so as to approach the inner surface of the lining and the outer surface of the lining.

[0017]

Embodiments of the present invention will now be described with reference to the drawings.

FIGS. 1 and 2 show an example of a fire-resistant joint structure of a shield tunnel according to the present invention. This refractory joint structure is a joint at the joint surface between the rings. In the figure, 1 is a segment, 1a and 1b are joint surfaces between rings, 4a is a tenon,
4b is a tenon groove, 6 is a sealing material for stopping water, and 7 is a shear strip. These structures and materials are the same as those of the above-described prior art.

This refractory joint structure has a groove 1 for fitting a ventilation blocking material in a position opposed to each other at a position close to the inner surface side edge of the joining surface 1a, 1b of the segment 1.
The segments 0 and 10 are formed beforehand at the time of segment molding, and the heat-resistant ventilation blocking material 11 is fitted into each groove 10 to join the segments 1 and 1 together. As a result, the ventilation blocking members 11, 11 of the opposed concave grooves 10, 10 are elastically contacted with each other, thereby preventing hot air from entering the gap between the joining surfaces and conducting heat, and the water sealing material 6 Degradation by heat of inclusions having low heat resistance, such as the shear strip 7 and the shear strip 7, is prevented.

The ventilation blocking material 11 used here includes:
A silica-alumina-based blanket, a fire-resistant sealing material such as glass fiber, etc. can be used. 1
It can be kept below 00 ° C.

FIGS. 3 and 4 show another embodiment of the present invention. The same parts as those in the above-described example are denoted by the same reference numerals, and the description thereof will be omitted.

In this example, coking recesses 12, 12 are provided at the inner side edges of the inter-ring joint surfaces 1a, 1b of the segments 1, 1 and the segments 1, 1 are joined to each other to form a caulking gap 13 Is formed, and the gap is filled with a ventilation blocking material 14 made of a caulking material.

At the time of filling the caulking material, a plate-shaped inflow prevention material 15 is filled in the inner part of the gap before filling, and then the gap 13 is filled so as to fill the gap. Incidentally, a silica-alumina-based paste can be used as the caulking material. In this case, even when the inner surface of the segment reaches the reference value of 380 ° C. for the buried tunnel in the Netherlands, the temperature of the outer surface of the segment of the caulking material can be kept at 100 ° C. or less.

In the example shown in FIGS. 3 and 4, even when a segment having no concave portion 12 is used, a gap 13 is formed by a dropper or the like after the lining assembly.
Caulking material may be filled.

Further, a joint structure having both the heat-insulating seal and the heat-insulating caulking shown in FIGS. 1 and 3 may be used. In this case, the heat-insulating effect is doubled.

Further, by applying the above-described ventilation blocking materials 11 and / or 14 to the inter-segment joint portion on the segment circumferential direction side shown in FIG.

Furthermore, the above-described example describes the joint of the shield tunnel with the tenoned segment. However, the present invention can also be applied to the joint of the shield tunnel using the ordinary segment having no tenon. In this case, As shown in FIG. 5, the sealing material 6 for waterproofing on the inner surface side of the lining.
Heat-resistant air-permeable shut-off materials 11 are installed on the inner side of the lining of the concave grooves 10a, 10a for accommodating the b, 6b to block the air from the inner side of the lining.

Further, as shown in FIG.
1b, coking recesses 12, 1 are formed on the inner side edge of the lining.
2 may be formed, and the caulking space 13 formed by these may be filled with a heat-resistant air-permeable blocking material 14.

[0029]

As described above, the inter-segment fire-resistant joint structure of the shield tunnel according to the present invention has a heat-resistant ventilation blocking material at a position close to the inner side edge of the segment between the joint surfaces around each segment. Even if the temperature of the segment surface reaches the standard value of 380 ° C for the buried tunnel in the Netherlands when the fireproof board is installed on the inner surface of the tunnel lining, the interposition of the joint part which changes at about 120 ° C to 160 ° C The material temperature can be kept below its transformation temperature.

A groove for fitting a ventilation blocking material is formed at a position close to an inner surface side edge of the joining surface around the segment so as to be opposed to each other between segments to be joined. By inserting a heat-resistant ventilation blocking material into each groove and sealing between the joint surfaces, at the construction site, it is possible to perform construction by a normal segment assembling process without requiring an additional process for fire resistance treatment. .

Further, a concave portion for caulking is provided at an edge of the joining surface around the segment on the inner surface side of the segment, and a caulking material is formed in a caulking space formed by the concave portions facing each other between segments joined to each other. By filling the ventilation blocking material, the fireproof treatment can be performed after the lining is formed even if the concave portion for the caulking space is not previously formed in the segment.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example in which a refractory joint structure between segments of a shield tunnel according to the present invention is applied to lining using tenoned segments.

FIG. 2 is a partially enlarged cross-sectional view showing a ventilation blocking member according to the first embodiment.

FIG. 3 is a sectional view showing another example of the above.

FIG. 4 is a partially enlarged cross-sectional view showing a ventilation blocking member according to the first embodiment.

FIG. 5 is a cross-sectional view showing an example in which the inter-segment fireproof joint structure of the shield tunnel according to the present invention is applied to lining using ordinary segments without a tenon.

FIG. 6 is a sectional view of another example of the above.

FIG. 7 is a cross-sectional view of a shield tunnel that has been subjected to a fireproof treatment by a conventional fireproof and heat insulating board.

FIG. 8 is a partially developed plan view showing an example of a conventional shield tunnel lining with a tenoned segment.

FIG. 9 is an enlarged cross-sectional view of the joint between rings in the same.

FIG. 10 is an enlarged cross-sectional view of a joint portion between segments in the same.

FIG. 11 is a perspective view showing an example of a tenoned segment of the above.

FIG. 12 is a cross-sectional view of a joint portion of a conventional shield tunnel lining with a tenon-free ordinary segment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 segment 1a, 1b Joint surface between rings 4a Mortise 4b Mortise groove 5 Bolt 6, 6a, 6b Sealing material for water stop 7 Shear strip 8 Transmission strip 10, 10a, 10b Concave groove for fitting a ventilation blocking material 11 Ventilation blocking material 12 Recess for caulking 13 void for caulking 14 ventilation blocking material 15 inflow prevention material

Claims (5)

[Claims] 1. A joint between each segment when extending a shield tunnel lining by connecting a lining ring in which a plurality of segments are assembled into a circular ring shape in a digging direction,
An inter-segment fire-resistant joint structure of a shield tunnel, wherein a heat-resistant ventilation blocking material is interposed at a position close to an inner side edge of a segment between joint surfaces around each segment. 2. A groove for fitting a ventilation blocking material is formed at a position close to an inner surface side edge of a joining surface around a segment at a position opposed to each other between segments joined to each other. 2. The structure according to claim 1, wherein a heat-resistant ventilation blocking material is fitted into each of the concave grooves to seal the joint surfaces. 3. A caulking recess is provided at an inner surface side edge of a joining surface around a segment, and a caulking material is formed in a caulking space formed by the recesses facing each other between segments joined to each other. The inter-segment fireproof joint structure of a shield tunnel according to claim 1 or 2, which is filled with a ventilation blocking material. 4. A mortise segment in which a tenon and a tenon groove formed on a joint surface of each segment between lining rings are fitted and joined to each other. 4. The joint-to-segment refractory joint structure of a shield tunnel according to claim 1, wherein the joint is a joint having a shear strip interposed therebetween. 5. A seal member for waterproofing, wherein the segments are ordinary segments connected by joining flat joining surfaces, and between the joining surfaces of the ordinary segments, the inner surface of the lining and the outer surface of the lining are brought close to each other. Claim 1, wherein the joint is formed by interposing
4. The inter-segment refractory joint structure of the shield tunnel according to 2 or 3.