JP2001329793A - Flexible joint for secondary lining inner pipe for shield tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible joint for secondary lining inner pipe, being thin in wall thickness in the clearance between the outer peripheral surface of the inner pipe and the inner peripheral surface of a segment and prevented from projecting markedly over the outer peripheral surface of the inner pipe. SOLUTION: A flexible water stop member 4 of short cylinder shape having a U-shaped bulge part 4c bulged to the inner peripheral side, at the center part, is disposed across detachment preventive projecting parts 6, 6' of short pipes 3, 3' so that the inner peripheral surface of the bulge part 4c forms the same peripheral surface as the inner peripheral surfaces 3a, 3a' of the short pipes 3, 3' by jointing each outer side face of the bulge part 4c to the respective end faces 6a, 6a' on the opposed sides of the detachment preventive projecting parts 6, 6'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint used for connection of a culvert such as water and sewage, a common ditch, and more particularly to a flexible joint used for connecting a pipe inside a secondary lining of a shield tunnel.

[0002]

2. Description of the Related Art Conventionally, construction methods for constructing culverts such as sewers by shield tunnels have been actively performed, and secondary lining of such shield tunnels is generally wound up using cast-in-place concrete. .

However, such secondary lining with cast-in-place concrete has problems in workability, water stoppage, durability and the like. Recently, reinforced plastic composite pipes (FRPM) have been used.
Pipe) into the tunnel, which is firstly wrapped with a shield segment, and fill the gap between the FRPM pipe (hereinafter referred to as “inner pipe”) and the shield segment with air mortar for positioning and fixing the inner pipe. A method called the FW-L method for performing the next lining has been performed.

[0004] Normally, the inner pipes are directly connected to each other. However, in order to cope with ground deformation caused by an earthquake or the like, adjacent inner pipes are connected to each other at appropriate locations by flexible joints.
As this flexible joint, for example, one shown in the partial sectional view of FIG. 8 is used. In the flexible joint a, a pair of short tubes b and b 'are arranged at a predetermined interval, and the short tube b and b' are straddled to form the outer rubber c, the inner rubber d and the inner rubber e. It is composed of three rubber layers, and a reinforcing ring f is embedded in the inner rubber d. G is the joint a
And a joint material such as foamed rubber for forming joints between the mortar and the air mortar.

[0005] This joint operates so as to follow the displacement by the expansion and contraction of the three rubber layers when the ground changes due to an earthquake or the like.

[0006]

The diameter of the inner pipe used in the FW-L method is determined by various conditions such as the amount of fluid and pipe resistance, and the diameter of the shield segment is determined according to the diameter of the inner pipe. However, it is desirable that the diameter of the shield segment be as small as possible in order to save construction costs. Therefore, it is necessary to make the gap between the outer peripheral surface of the inner pipe and the inner peripheral face of the segment as small as possible.However, it is necessary to take into account the construction error of the segment and the inner pipe and the space for inserting the air mortar injection pipe. Instead, this gap must be set from the maximum outer diameter of the inner tube and the flexible joint. However, in the conventional inner pipe flexible joint for the FW-L method, the height of the three rubber layers is 70 mm to 90 mm, and the difference between the outer diameter of the collar and the inner diameter of the inner pipe at the connection portion which is the highest part of the inner pipe is about 50 mm. In this state, the rubber portion of the joint is significantly protruded into the gap. Therefore, the size of the outer diameter of this flexible joint (the degree of protrusion into the gap)
However, this has prevented the segment diameter from being reduced, and has become a major obstacle in reducing costs.

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional inner pipe flexible joint for the FW-L method, and has a thin wall, an inner pipe outer peripheral surface and a segment inner peripheral surface. It is an object of the present invention to provide a flexible joint for a secondary lining inner pipe which does not significantly protrude beyond the outer peripheral surface of the inner pipe into the gap.

[0008]

A flexible joint for a shield tunnel secondary lining inner pipe which achieves the above object of the present invention comprises forming a primary lining with a plurality of segments including a flexible segment in a shield tunnel, A pair of inner pipes formed as secondary linings inside the primary lining have a connection portion with the inner pipe at one end and a separation prevention projection rising up toward the outer peripheral side at the other end. The short pipe is disposed so that the detachment prevention projections face each other at a predetermined interval, and is made of rubber, synthetic resin, or the like, and has a U-shaped bulging portion bulging inward in the center at the center. A cylindrical flexible water blocking member is bonded to each of the outer surfaces of the bulging portion on each of the opposite end surfaces of the separation preventing projection of the short tube, and the inner peripheral surface of the bulging portion is formed of the short tube. The same peripheral surface as the inner peripheral surface is formed, and it is arranged so as to straddle the separation prevention protrusion. The one in which the features.

In one aspect of the present invention, an elastic filling member made of foam rubber or foam resin is disposed in an annular space formed by the bulging portion of the flexible water blocking member.

[0010]

According to the present invention, the flexible water-stopping member can cope with displacement not by linear expansion and contraction of the rubber layer but by expansion and bending of the U-shaped bulging portion. A flexible joint for a secondary lining inner pipe can be provided which does not need to be thick and does not significantly protrude beyond the outer circumference of the inner pipe in the gap between the outer circumference of the inner pipe and the inner circumference of the segment.

Also, since each outer surface of the bulging portion is bonded to each end surface of the short tube on the opposite side of the detachment preventing projection, the joint force can be appropriately set by setting the bonding force of the bonding portion. However, if the distance between the short pipes is increased in the direction in which the distance between the short pipes increases, a slight displacement equal to or less than a predetermined value may follow the displacement by expanding the bulge portion on the inner peripheral surface side without peeling the adhesive portion. It is possible to maintain the smoothness of the inner surface of the pipeline. Further, even if the adhesive portion is partially or completely peeled off from the inner peripheral side due to the displacement exceeding the predetermined value, the gap generated between each outer surface of the bulging portion and the end face of the separation preventing protrusion is relatively small. Therefore, it is possible to minimize the possibility that dust or the like flowing in the pipeline is clogged in the gap and increases pipeline resistance.

In addition, by disposing an elastic filling member made of foamed rubber or foamed resin in an annular space formed by the bulging portion of the flexible water blocking member, it is driven after the inner pipe is installed. It is possible to prevent the air mortar from entering the annular space formed by the bulging portion, to secure the deformation space of the flexible water blocking member, and to prevent the flexible water blocking member bulging portion by the water pressure in the inner pipe. Deformation to the outer peripheral side can be prevented.

[0013]

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

FIG. 1 is a partial cross-sectional view showing one configuration example of a flexible joint for a secondary pipe in a shield tunnel secondary lining according to the present invention. This embodiment is an embodiment suitable for assembling the joint 1 in a factory.

A pair of inner tubes to be connected (FRPM tubes)
The shield segments 7, 7 'are provided on the inner peripheral side of the annularly disposed shield segments 7, 7' constituting the primary lining body of the shield tunnel with a predetermined interval therebetween. Are provided. Short cylindrical collars 8, 8 'are adhesively fixed to the outer peripheral surfaces of the opposed ends 2a, 2a' of the inner tubes 2, 2 'so as to protrude axially inward from the ends 2a, 2a'. And flexible joint 1
And the connecting portions 9 and 9 ′.

The flexible joint 1 connects the inner pipes 2 and 2 ′, and is composed of a pair of steel short pipes 3 and 3 ′ and a flexible water blocking member 4. The short pipes 3 and 3 ′ are connected to the inner pipes 2 and 2 ′ by connecting a short tubular connection pipe to an axially outer end outer peripheral surface and fixed by welding. At the inner end in the axial direction, detachment preventing protrusions 6 and 6 'that rise toward the outer peripheral side are formed. The short pipes 3, 3 'are arranged such that their separation preventing projections 6, 6' face each other at a predetermined interval, and their connecting parts 5, 5 'are connected to the connecting parts 9 of the inner pipes 2, 2'. , 9 'to be inserted into the inner tube 2, 2'
It is connected to the. A plurality of waterproof rubber rings 10, 10 'are interposed between the outer peripheral surfaces of the connecting portions 5, 5' of the joint 1 and the inner peripheral surfaces of the connecting portions 9, 9 'of the inner tubes 2, 2'. ing. The inner peripheral surfaces 3a, 3a 'of the short tubes 3, 3' are designed to have the same thickness as the inner peripheral surfaces 2b, 2b 'of the inner tube 2'.

The flexible water-stopping member 4 is formed by forming a flexible member such as rubber or synthetic resin into a short tubular shape, and is formed at both ends as shown in an enlarged partial sectional view of FIG. Fixed portions 4a, 4a 'having a substantially triangular cross section and annular detachment preventing protrusion fitting grooves 4b, 4b' adjacent to the fixing portions 4a, 4a '. The central portion between the two is a U-shaped bulging portion 4 with an opening facing the outer peripheral side and bulging inward.
c. Separation preventing protrusion fitting grooves 4b, 4b '
The depth of the end face on the fixing portion 4a, 4a 'side is
It is shorter than the depth of the end face on the c side, and the difference d in the depth is formed so as to be substantially equal to the thickness of the short pipes 3 and 3 ′. Therefore, when the flexible water blocking member 4 is fixed to the short tubes 3, 3 ', the inner peripheral surface 4d of the bulging portion 4c has the same inner peripheral surfaces as the inner peripheral surfaces 3a, 3a' of the short tubes 3, 3 '. Form. In the illustrated embodiment, the reinforcing cloth 11 is embedded in the flexible water blocking member 4, but the reinforcing cloth 11 can be omitted depending on the laying conditions of the joint. In the illustrated embodiment, the reinforcing annular wires 12, 12 'are buried in the fixing portions 4a, 4a', but these wires can also be omitted depending on the laying conditions of the joint.

The flexible water blocking member 4 is provided with a separation preventing protrusion fitting groove 4.
b, 4b ', the inner peripheral end faces 4e, 4e' of the fixing portions 4a, 4a 'are fitted so that the anti-disengagement projections 6, 6' are fitted to the short pipes 3, 3 '. ′ Is fixed to the short tubes 3 and 3 ′ by arranging them on the outer peripheral surface in the axial direction and baking them. Further, the outer surfaces 4f, 4f 'of the bulging portion 4c.
Are end faces 6a, 6 on opposite sides of the separation preventing projections 6, 6 '.
a ′ is adhered by an adhesive.

As described above, the flexible water-stopping member 4 is configured to respond to the displacement not by the linear expansion and contraction of the rubber layer but by the expansion and bending of the U-shaped bulging portion. The height of the U-shaped bulging portion 4c is the height of the collars 8, 8 'of the inner tubes 2, 2'.
Can be formed at substantially the same height as or slightly larger than the outer peripheral surface of the inner tube 2, so that it is not necessary to increase the thickness of the bulging portion 4c, and the height of the flexible water-stopping member 4 can be increased. Color 8,
It is possible to design it to be approximately the same height as the outer peripheral surface of 8 'or slightly higher than the height of the collars 8, 8'. Therefore, the joint 1 does not protrude significantly beyond the outer peripheral surfaces of the inner tubes 2, 2 'into the gap between the outer peripheral surfaces of the inner tubes 2, 2' and the inner peripheral surfaces of the segments 7, 7 '. The diameter of 7, 7 'can be reduced.

In the space formed by the bulging portion 4c of the flexible water-stopping member 4, an annular filling member 20 made of foam rubber, foam resin or the like and having a rectangular cross section and having elasticity is disposed.

The segments 7, 7 'which are part of the shield segment constituting the primary lining of the shield tunnel are connected by a shield segment flexible joint 13. The joint 13 has annular main girders 14 and 14 ′ arranged at a distance from each other, and a short cylindrical flexible member made of rubber, synthetic resin or the like arranged between the main girders 14 and 14 ′. It is of a known configuration including a water stopping member 15, and has a main girder 14, 1
4 ′ is fixed to the segments 7, 7 ′ by bolt nuts 16, 16 ′, the flexible water blocking member 15 has a bulging portion bulging inward at the center, and both ends are bolt nuts 1.
7 and 17 ', the main girder 1 via the holding plate 22, 22'.
4, 14 '. Joint members 18 and 19 are attached to the outer and inner peripheral sides of the flexible water blocking member 15. A cover plate 24 has one end welded to one of the main girders 14 and 14 '.

An air mortar 2 for positioning and fixing the inner tubes 2, 2 'is provided in the gaps between the inner tubes 2, 2', the flexible joint 1 and the shield segments 7, 7 ', and the flexible joint 13.
1 is filled.

The flexible joint 1 is brought to the shield tunnel construction site in a state where it is assembled in a factory, and the inner pipe 2
2 '.

Next, the operation of the flexible joint 1 will be described.

In the state shown in FIG. 1 showing the state when the joint 1 is completely installed, the outer side surfaces 4f, 4f 'of the bulging portion 4c are opposed to the detachment preventing projections 6, 6' of the short tubes 3, 3 '. Side end face 6
The inner peripheral surface 4d of the bulging portion 4c forms the same peripheral surface as the inner peripheral surfaces 3a, 3a 'of the short tubes 3, 3'. Therefore, the joint 1 is formed on the entire inner peripheral surface to have the same inner peripheral surface as the inner pipes 2 and 2 '. Therefore, there is no possibility that dirt or the like in the fluid flowing through the pipeline is clogged between the bulging portion 4c and the separation preventing protrusions 6 and 6 '.
Further, since the elastic filling member 20 made of foamed rubber or foamed resin is disposed in the annular space formed by the bulging portion 4c of the flexible water-stopping member, it is cast after the inner pipe is installed. The air mortar 21 is prevented from entering into the annular space formed by the bulging portion 4c, a space for deforming the flexible water-blocking member is secured, and the flexible water-blocking member bulging portion 4c due to the water pressure in the inner pipe. Is prevented from deforming toward the outer periphery.

Since the bonding force of the bonding portion is set to an appropriate predetermined value, if a tensile force acts in the direction in which the joint 1 expands in the axial direction due to ground deformation such as an earthquake, a slight displacement of less than the predetermined value will occur. In this case, the bulging portion on the inner peripheral surface side can be extended without expanding the adhesive portion, thereby following the displacement and maintaining the smoothness of the inner surface of the conduit.

Further, even when the displacement exceeds the predetermined value, as shown in FIG. 3, even if the adhesive portion is partially or completely peeled off from the inner peripheral side, each of the outer surfaces 4f, 4f
Since the gap G generated between f ′ and the separation-preventing projection end faces 6a, 6a ′ is relatively small, it is possible to minimize the possibility that dust or the like flowing in the pipeline becomes clogged in the gap G and increases the pipeline resistance. Can be stopped.

When a compressive force acts in a direction in which the joint 1 is compressed in the axial direction, the bulging portion 4c bends and contracts as shown in FIG. Is extremely small, it is possible in this case to minimize the possibility that dust or the like flowing in the pipeline will clog the recess R and increase the pipeline resistance.

Another configuration example of the present invention will be described with reference to the partial sectional view of FIG. In the embodiment of FIG. 5, the same components as those of the embodiment of FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

The embodiment of FIG. 5 can be assembled in a factory, but is an example of a configuration suitable for on-site construction at a construction site of a shield tunnel. FIG. 7 shows a flexible water blocking member 31.
FIG. 4 is an enlarged cross-sectional view showing a mounting structure portion of FIG.

While the short tubes 3, 3 'of FIG. 1 are made of steel, the short tubes 3, 3' of the flexible joint 30 of FIG.
It consists of an FRPM tube of the same material as 2 '. The short pipes 3 and 3 ′ are fitted with adhesively fixed short pipe resin connection pipes 5 and 5 ′ on the outer peripheral surface of the axially outer end portion, and the inner pipe 2.
2 '. Also, at the inner end in the axial direction, the separation preventing protrusions 6 and 6 ′ rising toward the outer peripheral side.
Is formed of the same material as the inner tubes 2, 2 ', and the short tubes 3,
3 'is adhered to the outer peripheral surface. In addition, the inner pipe 2, at a predetermined distance axially outward from the detachment preventing projections 6, 6 ',
Bolt mounting rings 32, 32 'made of the same material as 2'
Are adhered and fixed to the outer peripheral surfaces of the short tubes 3 and 3 '. A plurality of bolt insertion holes 33 (FIG. 7) are formed at predetermined intervals around the entire circumference of the bolt mounting rings 32 and 32 ′. Portions of the bolt mounting rings 32 and 32 ′ are located inside the bolt insertion holes 33 in the axial direction. Is the nut 3 of the bolt jack 34
A counterbore hole 32a having the same shape as the nut 35 is formed to prevent the nut 5 from rotating with the rotation of the bolt 36 of the bolt jack 34. The bolt 36 of the bolt jack 34 is inserted into the bolt insertion hole 33 and the counterbore 3
It is screwed with a nut 35 fitted in 2a.

The flexible water-stopping member 31 includes plate-shaped fixing portions 31a, 31a 'extending in the radial direction of the short tubes 3, 3', annular detaching prevention protrusion fitting grooves 31b, 31b ', and a U-shape. A fixing portion 31a, 31a 'is provided with a bulging portion 31c, and a flexible water-stopping member holding ring 37, 3 made of an annular member having a T-shaped cross section.
It is fixed by being pressed against the separation preventing projections 6 and 6 ′ by a bolt jack 34 via 7 ′. The flexible water-stopping member retaining rings 37, 37 'are divided into a plurality of portions in the circumferential direction, and each of the divided portions is provided with a connecting plate 38 provided at both ends.
They are interconnected by bolting them together. The outer surfaces 31d and 31d 'of the bulging portion 31c are bonded to the respective short surfaces on the opposite sides of the separation preventing protrusions 6 and 6' with an adhesive.

In the primary lining portion of the shield segment, both ends of the flexible water-stopping member 15 of the flexible joint 38 are held down by pressing plates 40, 4 by virtue of mounting members 39, 39 'of the type of a vise.
It is attached to the main girder 14, 14 'via 0'.
As shown in the partial perspective view of FIG.
It is composed of an inverted L-shaped annular member, and is divided into a plurality of portions in the circumferential direction.
0a, 40a 'are connected to each other by bolting. Reference numeral 41 denotes a reinforcing rib. A plate portion 40 on the outside in the axial direction of the holding plates 40, 40 '.
b, vise-type mounting brackets 39, 3 inside b, 40b '
The flexible water blocking member 15 is attached to the plate-shaped portions 39b, 39b 'and the main beams 14, 1
Fixed between 4 '. Note that in FIG.
Denotes a connecting plate for connecting the divided portions of the main beams 14, 14 'divided into a plurality of portions in the circumferential direction.

When assembling the flexible joint 30 shown in FIG. 5 in a shield tunnel construction site, the flexible water blocking member 31 is arranged so as to straddle the short pipes 3 and 3 ', and then the holding ring 3 is provided.
7 and 37 ′ are fixed to the fixing portions 31 a and 31 of the flexible water blocking member 31.
The fixing portions 31a, 31a 'are disposed between the a' and the bolt mounting rings 32, 32 ', and the bolt jacks 34 press the fixing portions 31a, 31a' against the disengagement preventing protrusions 6, 6 'to fix them. Although the constituent layers of the FRPM tube are separated at a high temperature, the flexible joint 1 of FIG. 1 is fixed to the short tubes 3, 3 'by baking the fixing portions 4, 4' of the flexible water-stopping member 4. When the short pipes 3 and 3 'are formed of FRPM pipes, the constituent layers are separated due to the high temperature during baking, which is not preferable.

In the embodiment shown in FIG. 5, since the fixing portions 31a and 31a 'of the flexible water blocking member 31 are fixed by the bolt jacks 34, no high temperature is used. For example, the short pipes 3 and 3 'can be constituted by the same FRPM pipe as the inner pipes 2 and 2'.
There is an advantage that the short pipes 3 and 3 'can be provided with the same high corrosion resistance as the inner pipes 2 and 2'.

[0036]

As described above, according to the present invention, the flexible water blocking member responds to the displacement by expanding and bending the U-shaped bulging portion, not by the linear expansion and contraction of the rubber layer. It is not necessary to make the rubber thick, and it is not necessary to protrude beyond the outer peripheral surface of the inner tube into the gap between the outer peripheral surface of the inner tube and the inner peripheral surface of the segment. Fittings can be provided.

Further, since each outer surface of the bulging portion is bonded to each end surface of the short pipe on the opposite side of the detachment preventing projection, the joint force can be appropriately set by setting the bonding force of the bonding portion. However, if the distance between the short pipes is increased in the direction in which the distance between the short pipes increases, a slight displacement equal to or less than a predetermined value may follow the displacement by expanding the bulge portion on the inner peripheral surface side without peeling the adhesive portion. It is possible to maintain the smoothness of the inner surface of the pipeline. Further, even if the adhesive portion is partially or completely peeled off from the inner peripheral side due to the displacement exceeding the predetermined value, the gap generated between each outer surface of the bulging portion and the end face of the separation preventing protrusion is relatively small. Therefore, it is possible to minimize the possibility that dust or the like flowing in the pipeline is clogged in the gap and increases pipeline resistance.

In addition, by disposing an elastic filling member made of foamed rubber or foamed resin in an annular space formed by the bulging portion of the flexible water-stopping member, it is driven after the inner pipe is installed. It is possible to prevent the air mortar from entering the annular space formed by the bulging portion, to secure the deformation space of the flexible water blocking member, and to prevent the flexible water blocking member bulging portion by the water pressure in the inner pipe. Deformation to the outer peripheral side can be prevented.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing one embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a flexible water blocking member.

FIG. 3 is a view showing a state in which a flexible water blocking member is expanded.

FIG. 4 is a view showing a state in which a flexible water blocking member is bent and reduced.

FIG. 5 is a partial cross-sectional view showing another embodiment of the present invention.

FIG. 6 is a partial perspective view showing a holding plate of the shield segment joint.

FIG. 7 is an enlarged sectional view showing a mounting structure of a flexible water blocking member.

FIG. 8 is a partial sectional view showing a conventional inner pipe flexible joint for FW-L method.

[Explanation of symbols]

 1, 30 Joint 2, 2 'Inner pipe 3, 3' Short pipe 4, 31 Flexible water-blocking member 5, 5 'Connection 6, 6' Separation preventing projection 4c, 31c Swelling part 20 Filling member 7, 7 '' Shield segment 15, 38 Flexible joint for shield segment

Claims (2)

[Claims] In a shield tunnel, a primary lining is formed by a plurality of segments including a flexible segment,
A pair of inner pipes formed as secondary linings inside the primary lining have a connection portion with the inner pipe at one end and a separation prevention projection rising up toward the outer peripheral side at the other end. The short pipe is disposed so that the detachment prevention projections face each other at a predetermined interval, and is made of rubber, synthetic resin, or the like, and has a U-shaped bulging portion bulging inward in the center at the center. A cylindrical flexible water blocking member,
Each outer surface of the bulging portion is bonded to each end surface of the short tube on the opposite side of the detachment prevention projection, and the inner peripheral surface of the bulging portion forms the same peripheral surface as the inner peripheral surface of the short tube. A flexible joint for a pipe in a shield tunnel secondary lining, which is disposed so as to straddle the detachment preventing projection. 2. An elastic filling member made of foamed rubber or foamed resin is disposed in an annular space formed by a bulging portion of the flexible water blocking member. Flexible joint for pipes inside secondary lining of shield tunnel.