JP2681612B2 - Sediment intrusion prevention structure at joints of underground structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing intrusion of sediment in joints of structures constructed underground, such as water and sewage systems, subways, common ditches, tunnels, underpasses, underground malls, and various underground tunnels.

[0002]

2. Description of the Related Art Conventional joints for underground structures, for example, underdrain joints, have a pair of tubular cylindrical underframes that are anchored to each other at their opposite ends and are made of rubber or synthetic resin. Both ends of a flexible water blocking member made of elastic material such as a short tube are watertightly attached to the inner peripheral surfaces of the two frame bodies facing each other, and the shaft of the underdrain accompanying uneven settlement of the ground There is a type that absorbs relative displacement in the direction and stops water between these underdrains.

For example, the applicant of the present invention has previously disclosed, as shown in a vertical section in FIG. 17 (a), Japanese Patent Publication No. 63-58982, a pair of opposing inner culverts 91, 91 'of the inner circumference of the end face. Steps 92, 92 'formed on the surfaces 91a, 91'a
Is formed into a short tubular shape made of an elastic material such as rubber or synthetic resin, and has an annular constricted portion 93a in the center,
Anchor flange portion 9 extending from both sides of this constricted portion 93a
A flexible water blocking member 93 having 3b, 93'b is fixed at anchoring flange portions 93b, 93'b, and step portions 92, 9 are provided.
Space portion 9 formed between 2 ′ and flexible water blocking member 93
4 and 94 'are provided with protective members 95 and 95' for preventing the flexible water-stopping member 93 from bulging in the axial direction (left-right direction in the drawing) and anchoring flange portions 93b and 93 of the flexible water-stopping member 93. The joint of the culvert 91, 91 'which was detachably interposed from the inside of the culvert 91, 91' inside the 'b was proposed.

[0004] In the joint of the culverts 91, 91 'shown by this proposal, the flexible culverts 93 make the culverts 91, 91'.
When water is prevented from leaking into the interior, and when the ground is unevenly settled and the underdrain 91, 91 ′ is largely displaced in the axial direction, the constricted portion 93 a of the flexible water blocking member 93 extends and the underdrain 91, 9 ′.
Absorbs the relative displacement of 1'and culverts 91, 91 '
Since the joint material 96 made of a foam (sponge body) such as rubber or synthetic resin is sandwiched between the end faces of the ring, even if the joint width is slightly enlarged to form a gap, the gap is small. Is prevented from entering the concave portion 93c formed by the constricted portion 93a due to an arch effect of the earth and sand that try to enter.

Therefore, the maximum value of the joint width (distance between the end faces of the opposing underdrain 91, 91 ') allowed in the conventional underdrain joint is about 30 to 40 mm, whereas the underground structure according to this proposal. The joint is equipped with a large unequal subsidence, and the maximum joint width has been expanded to around 100 mm to accommodate earthquakes with large amplitude. However, since the joint material 96 does not follow the extension of the joint, the earth and sand enter the concave portion 93c formed in the constricted portion 93a through the gap created between the joint material and the underdrain end face due to the extension, and the invading earth and sediment accumulate and solidify. Then, there is a weak point that the expansion and contraction of the flexible water blocking member is hindered and the expansion and contraction function of the joint is deteriorated.

[0006]

By the way, in addition to external water pressure, earth and sand pressure acts around the underground structure buried in the soil. Normally, the external pressure acting on the underground structure is usually less than 10 m and the burial depth is less than 10 m, and it is 1 kg / cm ^{2 to 2} kg / cm ² , but recently the mounting position is in the soil, and the external pressure is 3 to 5 k.
The external pressure tends to increase to g / cm ² .

Therefore, as a result of further studies by the present inventor, in the joint of the underdrain according to the above-mentioned proposal, the ground moves due to, for example, seismic motion to cause a gap between the underdrain 91, 91 'as shown in FIG. 17 (b). When a large relative displacement of about 100 mm is generated in the axial direction, the gap 97 between the joint material 96 and the end face of the underdrain 91 ′, which is generated due to this relative displacement, passes through the underdrain 91,
The earth and sand around 91 'intrude into the recess 93c of the flexible water blocking member 93 together with the outside water.

[0008] Even if earth and sand enter the concave portion 93c, it is prevented by the flexible water blocking member 93, so that there is no problem such as intrusion into the culverts 91 and 91 '.
The earth and sand that have entered the concave portions 93c gradually accumulate and solidify as shown in FIG. 17C, so that the movement of the constricted portion 93a of the flexible water blocking member 93 is restricted. for that reason,
In this state, if relative displacement occurs between the culverts 91 and 91 ′ due to seismic motion or the like, the accumulated sediment restricts the behavior of the flexible water blocking member 93, and the constricted portion 93a follows the relative displacement of the culverts 91 and 91 ′. And cannot be expanded or contracted. If the flexible water blocking member 93 cannot expand or contract, the internal stress of the flexible water blocking member 93 increases as the relative displacement between the underdrain 91 and 91 'increases, and the anchoring flange portion 93b of the flexible water blocking member 93 increases. 9
There is a possibility that stress acts on 3'b to cause water leakage. Since the flexible water blocking member 93 is used by being buried in the soil together with the culverts 91 and 91 ', it is extremely difficult to check the accumulation state of the earth and sand in the concave portion 93c. It is important that sediment does not accumulate in the recess 93c.

[0009] In addition, the burial position of a culvert has been deeper in the soil than ever before, and it is expected that such burial position will continue to be deepened in the future. Therefore, the pressure resistance of the underdrain joint is also required to be improved, and the conventional underdrain 91 and the underdrain 91 shown in FIGS.
In the joint 91 ′, for example, a reinforcing material such as a reinforcing cloth or a reinforcing cord is incorporated inside the flexible water-stopping member 93 to form a molded product to improve the pressure resistance of the flexible water-stopping member 93. It is common to plan.

[0010] The relative displacement between the culverts causes the flexible water blocking member 93 to move.
Is extended from the state of FIG. 17 (a) to the state of FIG. 17 (b),
The ring-shaped flexible water blocking member 93 has a diameter increased by an amount indicated by symbol h in FIG. 17 (b). For example, in a circular underdrain, the inner diameter is 2
Since it increases by h, the joint can absorb the extension between the underdrain only when the flexible water blocking member 93 extends in the circumferential direction by 2hπ. However, the flexible stretchable water member with a reinforcing material such as a reinforcing cloth or cord has a stretch rate of about 20% when cut, and the allowable stretch rate of the flexible waterproof member without the reinforcement material considers durability. Then, the allowable elongation rate is greatly reduced as compared with about 50%. Therefore, as the burying position increases in depth, if the number of reinforcing materials to be added to the flexible water blocking member is increased,
This causes a problem that the amount of the flexible water blocking member that can follow the relative displacement between the underdrains decreases.

Further, the flexible water-stopping member 9
Even if the pressure resistance of No. 3 is improved, if the buried position is deepened further, as shown in FIG.
Even if the relative displacement between the first and the first 91 ′ is small, the joint material 96 made of a sponge such as rubber or synthetic resin contracts due to the rise of the external pressure due to the deepening, and the soil and the sand are removed from the gap 97 ′ generated by the contraction. Constriction 93a of flexible water blocking member 93
The flexible water blocking member 93 also enters the recess 93c formed by the
It is impossible to expand and contract following the relative displacement of 1 '.

The present invention has been devised in view of the above problems, and relates to a joint for a structure constructed underground such as water and sewage, a subway, a common ditch, a tunnel, an underpass, an underground mall, and various underground tunnels. Due to a large relative displacement between the underground structures facing each other or the depth of the buried position of the underground structures, the sediment that has entered the joint space between the ends of the underground structures is accumulated and solidified in the constricted part of the flexible waterproofing member. Prevents the functional failure of the flexible waterproofing member and solves the problem that the allowable elongation of the flexible waterproofing member decreases with the increase of the reinforcing material in the flexible waterproofing member. It is intended to provide an intrusion prevention structure.

[0013]

Means for Solving the Problems A structure for preventing intrusion of sediment in a joint of an underground structure according to the present invention is made of an elastic material such as rubber or synthetic resin across each end of a pair of underground structures facing each other. In a joint of an underground structure equipped with a flexible water blocking member formed in a short tubular shape, the elasticity of rubber, synthetic resin, etc. placed in the joint space between the underground structures on the outer peripheral side of the flexible water blocking member. On the outer peripheral side of the joint material made of wood, a water-permeable sheet for preventing sediment invasion, which is made of a flexible material that allows water to pass through without allowing sand and sand to pass through, is attached across each end of the underground construction. It is characterized by having done.

[0014]

In the structure for preventing sediment intrusion in the joint of the underground structure according to the present invention, the structure is located on the outer peripheral side of the joint material arranged in the joint space between the underground structures on the outer peripheral side of the flexible water blocking member, Through a water-permeable sheet for preventing intrusion of sand, which is formed in the shape of a short cylinder made of a flexible material that does not allow the passage of earth and sand, to pass through each end of the underground structure, through the external water pressure and joint material. The flexible water blocking member has a function of withstanding the partial vertical earth pressure acting on the joint, and the water-permeable member for preventing sediment intrusion has a function of withstanding the sediment pressure excluding the partial vertical earth pressure acting on the joint material. In this way, since the load acting on the joint is shared by both sides, the load on the flexible water blocking member can be greatly reduced. Also,
When earth and sand and outside water try to invade into the joint space between underground structures, the outside water passes through the sediment infiltration permeable sheet and reaches the flexible water blocking member, but the earth and sand are trapped in the sheet. Therefore, it is possible to prevent functional failure of the flexible water blocking member due to sedimentation and solidification of earth and sand on the constricted portion of the flexible water blocking member.

Further, since the water-permeable sheet for preventing intrusion of sediment is installed so as to be located on the outer peripheral side of the joint material, when the relative displacement of the underground structure in the axial direction progresses, the joint material and the flexible water blocking member are provided. Even if a gap is generated between the flexible water blocking member and the flexible water blocking member, it is possible to prevent the surrounding soil from entering the constricted portion of the flexible water blocking member through this gap.

Further, even if the earth and sand try to invade the constricted portion of the flexible water blocking member, the earth and sand preventive sheet is mounted on the outer peripheral side of the joint material. Since it is captured by the elastic sheet, the external pressure applied to the joint material from the earth and sand is reduced. Therefore, the withstand pressure of the joint material can be lowered and set, the flexibility of the joint material can be increased, and the degree of freedom in setting the material of the joint material is increased.

Further, since the external water pressure is received by the flexible water blocking member and the earth and sand pressure is received by the permeable sheet for preventing intrusion of sand, the pressure applied to the flexible water blocking member can be reduced by the amount of earth and sand pressure. , Since it is possible to suppress the increase in withstand pressure of the flexible water blocking member required to cope with the deepening of the burial position to a minimum, it is possible to minimize the amount of the reinforcing material added, The followability of the flexible water blocking member with respect to the relative displacement between the underground structures is suppressed, and it is possible to sufficiently cope with a large relative displacement at a high depth.

An embodiment of a structure for preventing intrusion of earth and sand in a joint of an underground structure according to the present invention will be described below in detail with reference to the accompanying drawings.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a structure 2 of an underground structure 1 and 1'opposed to each other, in which a structure for preventing intrusion of sand in a structure of an underground structure according to the present invention is molded from concrete into a circular cross section.
It is a perspective view which shows the outline of the situation applied to.

In FIG. 1, end faces which are opposite ends of a pair of underground conduits 1 and 1 ′ which are underground structures facing each other are connected by a joint 2 of the underground structure.

2 to 7 show an embodiment in which the structure for preventing intrusion of sediment according to the present invention is applied to the joint of the underground structure shown in FIG. 1, and FIG. 2 is a sectional view taken along the line I--I in FIG. FIG. 3 is a perspective view showing the left half of FIG. 2 of a load bearing member used in the joint of the underground structure of the present embodiment, FIG. 4 is a perspective view showing a modification of this load bearing member, and FIGS. 5 and 6 show the load bearing member. FIGS. 7A and 7B are views showing various methods of fixing the constituting rod-shaped member to the plate-shaped member, and FIG. 7 is a perspective view of the push plate.

As shown in FIG. 2, stepped portions 3 and 3'are formed on the inner peripheral surface side edges of the opposite ends of the underground structures 1 and 1 '. Since the structure of the step portion 3 'is exactly the same as that of the step portion 3, the reference numerals used for the step portion 3 and the like are given the numbers with dashes, and the description of the step portion 3' and the like will be omitted.

Outer peripheral surfaces 3a, 3'a of the step portions 3, 3 '
A cylindrical anchoring member 4, 4 ′ is fixed to the base member. A short cylindrical flexible stopper made of an elastic material such as rubber or synthetic resin is provided between the anchoring members 4, 4 ′. A water member 6 is provided. The outer peripheral flexible water blocking member 6 has a substantially U-shaped cross section at its center.
It has an annular constricted portion 6a that bulges inward in the shape of a letter. Further, from both sides of the constricted portion 6a, the anchorage members 4, 4'extend in the axial direction of the underdrain 1, 1 '(left and right in the drawing).
And the inner peripheral surface of the end face of the step portion 3b, 3 '
The anchoring flange portions 6b and 6'b reaching b are integrally formed. The outermost flexible water blocking member 6 may be embedded with a minimum necessary reinforcing cloth (not shown) in order to increase its strength. Note that such a reinforcing cloth may be provided on both the outer peripheral flexible water blocking member 6 and the inner peripheral flexible water blocking member 7 described later. Further, the outer end portions 6c and 6'c of the anchoring flange portions 6b and 6'b of the outer peripheral flexible water blocking member 6 are projected to the inner peripheral side.

Between the anchor members 4 and 4 ', the inner circumference flexible water blocking member is formed on the inner circumference side of the outer circumference flexible water blocking member 6 from an elastic material such as rubber or synthetic resin in a short tubular shape. 7 are provided.
The inner-periphery flexible water-stopping member 7 has an annular constriction 7a at the center, which has a substantially U-shaped cross section and bulges toward the inner periphery.
The outer end portions 6c and 6'c of the anchoring flange portion of the outer circumferential flexible water blocking member 6 extend in the axial direction from both sides of the constricted portion 7a.
The anchoring flange portions 7b and 7'b that are in contact with the inner end surface of the are integrally formed.

Inner circumference flexible water blocking member 7, outer circumference flexible water blocking member 6
The material of is, for example, chloroprene synthetic rubber (CR) in consideration of aging resistance, ozone resistance, and abrasion resistance,
Natural rubber (NR) considering mechanical strength, high elasticity, durability, cold resistance, etc., soft vinyl chloride resin considering chemical resistance as synthetic resin, or ethylene and acetic acid considering chemical resistance and cold resistance. Copolymer of vinyl (EVA)
In particular, when made of rubber, a reinforcing cord such as vinylon cord, nylon cord or steel wire can be incorporated to the minimum necessary for the purpose of improving pressure resistance.

Outer peripheral flexible water blocking member 6 and inner peripheral flexible water blocking member 7
A load bearing member 9 having a curved portion 9a having a substantially U-shaped cross section and anchor portions 9b and 9'b extending in the axial direction from both sides of the curved portion 9a is formed in a small gap 8 formed between Curved part 9a
Are projected to the inner peripheral side, and the anchor portions 9b, 9'b
Is sandwiched between the anchoring flange portions 6b, 6'b of the outer peripheral flexible water blocking member 6 and the anchoring flange portions 7b, 7'b of the inner peripheral flexible water blocking member 7, and the anchoring portion Outer edges 9c, 9'c of 9b, 9'b are outer edge portions 6c, 6 of the outer peripheral flexible waterproofing member 6.
It is arranged so that it exists inside ‘c.

Anchor flange portion 6 of outer peripheral flexible water blocking member 6
b, the anchoring flange portion 7b of the inner flexible water blocking member 7 and the anchoring portions 9b and 9'b of the load bearing member 9 are bolts 10 and 10 'penetrating these members and anchoring members 4 and 4'. The nuts 11 and 11 'are screwed into the
'And the anchoring flange portions 7b and 7'b of the inner circumferential flexible water blocking member 7
And push plates 12, 12 'are interposed between the nuts 11, 11
By tightening ′ ′, they are pressure-bonded to the inner peripheral surfaces of the anchoring members 4, 4 ′, and are fixed in a watertight manner.

In this embodiment, as shown in FIG. 3, the bending portion 9a of the load-bearing member 9 is formed by a plurality of curved steel bars or other rod-like members 13 arranged at appropriate intervals in the circumferential direction of the joint 2. The anchoring portion 9b is composed of a plate-like member 14 such as a separate steel plate to which the plurality of rod-like members 13 are fixed by nuts 15 at both threaded ends thereof.
By arranging a plurality of the plate-like members 14 in the circumferential direction, an annular bearing member 9 is formed as a whole. Sign 1
Reference numeral 4a is an insertion hole for the bolt 10. The curved portion of the rod-shaped member 13 has a radius of curvature (R) at its corner portion that is as large as possible in order to easily support the load acting on the outer circumferential flexible water blocking member 6 by its tensile strength, and the overall shape is close to a semicircle. It is preferable to set as follows. With this configuration, unlike the conventional method of supporting the load by the cross-sectional bending resistance using a rod-shaped load bearing member, the load acting on the outer peripheral flexible water blocking member 6 is supported by the tensile strength of the load bearing member 9. Therefore, by appropriately selecting the material of the proof member 9, the cross-sectional area of the proof member 9 can be reduced without lowering the load supporting force. As described above, since the pressure-resistant mechanism is constituted by the proof member 9, there is little restriction on the extensional displacement of the U-shaped bottom length that occurs with the progress of displacement, and the displacement resistance can be reduced to set a large displacement amount.

Further, the proof member 9 is the outer peripheral flexible water blocking member 6
Since the flexible water blocking member 7 is completely attached to the inner flexible water blocking member 7, the load bearing member 9 is isolated from the corrosive environment and the oxygen supply is completely cut off. Therefore, there is almost no risk of corrosion, and it is extremely rich in corrosion resistance and excellent in durability.

Here, FIG. 19 is an explanatory view showing the structure of a conventional joint using an anchor box. In the figure, end portions of a plurality of load-bearing members 103 arranged circumferentially at intervals in a pair of annular anchoring boxes 102, 102 'attached to the end faces of a pair of underdrain 101, 101' to be connected. Is inserted and connected so that it can move within a certain range and cannot come off,
A plurality of load bearing members 1 are provided between both anchor boxes 102 and 102 '.
No. 03, which is arranged outside the annular row, and is watertightly connected by the flexible water blocking members 105 in the form of short cylinders whose ends are fixed to the side walls 104, 104 'of both anchor boxes 102 and 102'. A cylindrical body 106, which is slightly shorter than the initial distance between the side walls 104 and 104 'of both fixing boxes 102 and 102', on the outer periphery of the load bearing member 103.
Is loosely fitted.

As can be seen from FIG. 2, in this embodiment, in the conventional joint shown in FIG.
Fixing box 102, 102 'used to support the
(Normally made of iron), there are few places where the outer and outer flexible water blocking members 6 and inner flexible water blocking members 7 are fixed, and there are few steel surfaces in a corrosive environment, so there are few corrosion factors and corrosion countermeasures. Can be done easily. Furthermore, since there are few nut tightening points, repainting work for repairing peeling of the coating film of the nut at the time of tightening can be greatly reduced.

Further, when the joint 2 reaches the limit displacement,
The load bearing member 9 has a function of suppressing further progress of displacement. Therefore, the safety of the joint is secured.

FIG. 4 shows a modification of the proof member 9 shown in FIG. In the load-bearing member 9 of FIG. 3, a plurality of rod members 13 are fixed to one plate member 14, whereas the load-bearing member 9 of FIG. 4 is one rod member for one plate member 16. 13 in that the nut 13 is fixed by a nut 15. Reference numeral 15a is an insertion hole for the bolt 10.

As a method of fixing the rod-shaped member 13 forming the curved portion 9a of the load-bearing member 9 to the plate-shaped member 14 forming the anchored portion 9b, a rod-shaped member screwed as shown in FIGS. 3 and 4 is used. Method of fixing the end of 13 with a nut (Fig. 5
In addition to (a)), as shown in FIG. 5 (b), a method of welding the rod-shaped member 13 on the inner peripheral surface of the end of the plate-shaped member 14
5C, a method of bending the end of the rod 13 at a right angle and welding it to the inner peripheral surface of the protruding end 14a of the plate 14, as shown in FIG. 5D. 13 is a method in which the end of the rod 13 is bent and the tip is welded to the edge of the plate 14, and the linear end of the rod 13 is connected to the end of the plate 14 as shown in FIG. Method for welding to the edge, Fig. 6
As shown in (b), a through hole 14b is formed at the end of the protruding plate member 14, and the rod member 1 is inserted into the through hole 14b.
A method of inserting and welding the end portion of No. 3 and bending the end portion of the plate member 14 to the inner peripheral side at a right angle as shown in FIG.
A gap is formed between the bent end portion and the inner circumference flexible water blocking member 7, and the end portion of the rod-shaped member 13 is inserted into this gap to insert the plate-shaped member 1 into the gap.
Various fixing methods such as welding to the bent end of No. 4 can be used. These various fixing methods may be appropriately selected and used in consideration of the purpose of use of the joint, the place of use, and the like.

As shown in FIG. 7, the push plate 12 has bolts 1
Zero insertion holes 12a are provided at appropriate intervals. Screwing portions 12b are provided on one surface of the pressing plate 12 at appropriate intervals. In this embodiment, the screwed portion 12b is formed by welding a bulky bolt. However, the present invention is not limited to this.
Any material that can be fastened to the pressing plate 12 by screwing a protective material 17 described later with a bolt 18, such as a screw directly cut into 2, may be used.

Further, the threaded portion 12b is provided with the protective material 17 by the bolt 1
The number of bolt insertion holes 12a is usually smaller than the number of bolt insertion holes 12a because it does not apply a large external force.

As another method of attaching the protective member 17, the screw member 12b and the bolt 18 shown in FIG. 7 are not used, but a portion of the bolt 10 is made to extend the end portion on the axial center side of the underground structure to protect the protective member 17. Alternatively, the protective member 17 can be attached by tightening the protective member 17 with a nut.

A protective material 17 is provided in the space formed between the step portion 3 and the inner circumferential flexible water blocking member 7. The protective material 17 prevents the inner flexible water blocking member 7 from bulging and deforming in the axial direction of the underground structure, isolating the bolt 10 and the nut 11 from the corrosive environment, protecting them from external damage, and keeping the inner surface of the joint smooth. It is provided for this purpose, and is made of rubber, synthetic resin, or the like. For the protective material 17, the bolt 1
A bolt insertion hole (not shown) for inserting 8 is provided.

The outer peripheral end surface of the protective member 17 abuts on the inner peripheral surface of the push plate 12, the outer peripheral surface thereof abuts on the end surface portion 3b of the step portion 3, and the inner side surface of the protective material 17 is the constricted portion 7a of the inner peripheral flexible water blocking member 7. And is indirectly fixed to the anchoring member 4 by abutting on the side surface thereof. That is,
The protective member 17 is fixed to the push plate 12 by bolts 18, and is indirectly fixed to the anchor member 4 by fixing the push plate 12 to the anchor member 4 by fastening bolts 10 and nuts 11. .

In FIG. 2, reference numeral 19 prevents earth and sand from entering the joint space 20 between the underground structures 1 and 1'in normal times and allows relative movement between the underground structures 1 and 1'to some extent. It is a ring-shaped joint material made of sponge such as rubber and synthetic resin.

The joint material 19 is water-permeable open-cell property,
Alternatively, a water-impermeable closed-cell elastic material is used. The material may be a known material, for example,
Examples thereof include rubber-based (NR), chloroprene-based (CR), ethylene-propylene rubber (EPDM), urethane (U) resin-based, polyethylene-based, etc., and of open cell foam (sponge rubber, resin foam) Use is desirable. As the shape, a plate-shaped laminated body in an annular shape or a shape in which the joint material 19 has a cross-sectional shape is used. The characteristics required for the material of the joint material 19 are that it is lightweight, easy to cut, and easy to attach.
It has certain elasticity and excellent elasticity, does not stick out, does not collapse even after installation, and can withstand repeated expansion and contraction.

The cross-sectional shape of the joint material 19 may follow the U-shaped internal shape, but by forming a slit at the center of the cross-section or by using a vertically divided sponge body as the filling material. Further, it is possible to further improve the followability to the U-shaped displacement when the displacement progresses.

As described above, when the sponge body or foamed elastic material such as foamed polystyrene is used as the joint material 19, the load acting on the joint material 19 is only the underwater load of the soil. Since the load acting on the material 19 is reduced, it is possible to use a material having a relatively small repulsive force, and it is easy to follow the change in the U-shape of the joint material 19 with the progress of the displacement. It prevents the intrusion of earth and sand into the U-shape when traveling, and also reduces displacement resistance.

In this embodiment, the joint material 19 is positioned in the joint space on the outer peripheral surface side of the joint material 19 to form an annular shape.
A water-permeable sheet 22 for preventing intrusion of sediment having a U-shaped cross section is installed at each end of each of the two underground structures 1 and 1 ′ that come into contact with.

The sediment-permeable water-permeable sheet 22 is composed of, for example, a corrosion-resistant and water-permeable synthetic fiber or a non-woven fabric, or a combination of these with a corrosion-resistant wire mesh or the like as a core material, which allows water in the soil to permeate but traps the soil. It has a function. In the present embodiment, bolt insertion holes (not shown) are formed near the inner peripheral side end portions of the flange portions 31 and 31 ′ that rise radially outward from the opposite ends of the anchor portions 4 and 4 ′. ing. The water-permeable sheet 22 for preventing intrusion of earth and sand has its anchoring portion 2
2a and 22'a, a flange portion 3 for fixing the seat
Bolts 34, 34 'and nuts 35, 35 inserted into the bolt insertion holes of 1, 31' via push plates 33, 33 '.
It is fixed to the opposing side surfaces of the flange portions 31 and 31 'by ???. Further, the water permeability sheet 22 for preventing intrusion of sediment is provided with an expansion and contraction function by being arranged in a U-shaped cross section, and the relative displacement between the underground structures 1 and 1 ′ causes the end face of the underground structure and the joint material 19 to be separated. Even if there is a gap between the two, it extends so as to cover the gap and captures the earth and sand that try to pass through this gap.

As described above, the joint material 19 made of an elastic body (rubber or sponge body) having an appropriate repulsive force is attached by projecting a certain height on the upper part so as to fill the inside of the U-shape. At the same time, on the outer peripheral surface of the joint material 19, a water-permeable sheet 22 for preventing the intrusion of sediment is attached, the end portion of which is fixed to the flange portion 31.

The sediment-permeable water permeable sheet 22 stabilizes the shape of the joint material 19 when the displacement is proceeding, and can prevent the sediment from entering the U-shape when the displacement is proceeding. , It is possible to prevent the entry of earth and sand into the U-shape.

As the corrosion-resistant and water-permeable synthetic fiber, which is one of the materials of the water-permeable sheet 22 for preventing intrusion of earth and sand, for example, TP-1080, TP-, which is a curtain material using polyester fiber manufactured by Toyobo Co., Ltd. 1050 or even TP-
Examples include 1030 and TERRA-PAX (trade name), which is a canvas for civil engineering work manufactured by Toyobo Co., Ltd. In addition, as the non-woven fabric which is another material, for example, Mantle (registered trademark) which is a non-woven fabric for civil engineering work of TORAY, a stretch fiber manufactured by Fiber Engineering Co., Ltd. which is a resin net, and JIS G 3555 can be used. The specified woven wire mesh etc. can be illustrated.

Reference numeral 38 is an outer peripheral gap filler made of sponge rubber or the like for minimizing the intrusion of earth and sand into the outer periphery of the water and sand permeable sheet 22. Also, reference numeral 3
Reference numeral 9 denotes an outer peripheral skin plate in which the entire outer peripheral surface of the joint is covered with a thin steel plate or the like, which is used to secure the smoothness of the outer peripheral surface of the joint when the underdrain 1,1 'is constructed by the propulsion method or the shield method. However, it is not necessary to install it in the underdrain constructed by the open-cut method. 8 to 1
In the description of FIG. 2, the description of the outer peripheral gap filling material 38 and the outer peripheral skin plate 39 will be omitted, and FIGS.
Although not shown in the drawing in FIG. 6, since these have exactly the same configuration, the following description will be given assuming that they are installed in the same manner as in FIG.

As described above, in the joint shown in FIGS. 2 to 7, a large relative displacement is generated between the underground structures 1, 1 ′, or the depth of the buried position of the underground structures 1, 1 ′ is increased, so that the joint space is formed. Is opened in the axial direction of the underground structure 1, 1 ′ to create a gap between the joint material 19 and the underground structure 1, 1 ′, and when earth and sand accompanied by earth pressure tries to enter the joint space, Sediment is captured by the sediment-permeable water-permeable sheet 22 attached to the outer periphery of the joint material 19,
It is possible to prevent the sediment from entering and accumulating in the space 20 formed by the constricted portion 6a of the outer peripheral flexible water blocking member 6 and solidifying. Therefore, the elasticity of the outer peripheral flexible water blocking member 6 and the inner peripheral flexible water blocking member 7 is maintained.

Further, in the joint shown in FIGS. 2 to 7, the fixing box conventionally used for accommodating both end portions of the load bearing member is not required, so that the cross section of the load bearing member can be made small and the stopper can be formed. Since there are few bolts and nuts for water and assembling, there are few welded and assembled parts, there is little bending work to cut thick steel plates, there are few steel materials used, and there are no difficult parts for painting, so overall The cost can be reduced.

8 to 12 are explanatory views showing various embodiments in which the earth and sand intrusion prevention structure according to the present invention is applied to the joint of the underground structure shown in FIG. 2 with some modifications. In the various modifications shown in FIGS. 8 to 12, the same components as those of the embodiment of FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted. Further, in the embodiments shown in FIGS. 8 to 12, only the main parts of the joints are shown by the reference numerals, and the details are omitted as the occasion demands. Since the embodiment shown in FIG. 8 is symmetrical with respect to the center line XX ', the illustration on the right side is omitted.

FIG. 8 is a sectional view showing an embodiment in which the earth and sand intrusion prevention structure according to the present invention is partially modified and applied to the joint of the underground structure shown in FIG. In the embodiment shown in FIG. 8, a tubular frame 24 is fixed to the step portion 3. Frame 24
Is made of iron or resin, and the outer peripheral flange portion 24a fixed to the stepped portion and the underground structure 1 from the outer peripheral flange portion 24a.
An end surface portion 24b extending in the axial direction of the and a rising portion 24c protruding outward from the outer peripheral flange portion 24a are provided.

In this embodiment, the anchoring portion 9b of the load-bearing member 9 is formed in a plate shape, and a through hole 9f is formed in the protruding end portion thereof, and the through hole 9f is bent in a U shape. The end of the rod-shaped curved portion 9a is inserted so that its threaded tip faces the inner peripheral side, and the tip thereof is the nut 16
It is fixed at.

In the present embodiment, in order to fix the outer peripheral flexible water blocking member 6, the inner peripheral flexible water blocking member 7 and the load bearing member 9, the inner peripheral surface of the outer peripheral flange portion 24a of the frame 24 and the load bearing member. The anchoring flange portion 6b of the outer peripheral flexible waterproofing member 6 is sandwiched between the anchoring portion 9b of 9 and the primary nut 11-1 and screwed to the bolt 10 penetrating these members, Further, the anchoring flange portion 7b of the inner circumferential flexible water blocking member 7 and the push plate 12
By tightening the secondary nut 11-2 onto the through bolt 10 in a two-step manner, a strong tightening is realized.

Further, in this embodiment, the outer end edge 6d of the outer peripheral flexible water blocking member 6 terminates on the inner side as compared with the embodiment of FIG. 2, and the outer end edge 9c of the load bearing member 9 of the frame body 24. End face 2
It has been extended to 4b. An annular rigid body 30 made of a steel material, a hard resin, or the like is disposed between the outer end edge 6d of the outer peripheral flexible water blocking member 6 and the end surface portion 24b of the frame body 24.

In the rigid body 30, the fixing portion of the outer circumferential flexible water blocking member 6 is locally compressed by the large force acting on the fixing portion of the proof member 9 in the fixing portion of the joint subjected to earth pressure, and the compression thereof is performed. It is installed in order to avoid harmful deformation such as creep phenomenon that occurs over time due to force, and to prevent water resistance and fixability of the fixing part from being impaired.
This effect is exhibited in combination with the mounting of the bolt 10 and the primary nut 11-1.

When the joint receives an external pressure such as earth pressure, it is transmitted to the curved portion 9a of the proof member 9 through the external pressure and the constricted portion 6a of the outer peripheral flexible water blocking member 6, and the protruding end 9f of the fixing portion 9b.
If the projecting end 9f of the fixing portion 9b receives a strong load, the load near the central portion of the fixing portion 9b of the proof member 9 is simply supported and fixed by the bolt 10, the nut 11-1, etc. As a result, the fixing portion 9b tries to rotate around the portion where the bolt 10 penetrates. Therefore, the outer peripheral portion of the fixing flange 6b of the outer peripheral flexible water blocking member 6 and the roots of the fixing flange 7b of the inner peripheral flexible water blocking member 7 and the curved portion 7a are extremely compressed, which causes long-term use. As a result, plastic deformation (creep phenomenon) or the like is caused and the fixing portion becomes unstable, resulting in a decrease in fixing degree and water leakage. In order to prevent this, the rigid body 30 is provided.
Installation position and the primary nut 11 attached to the bolt 10
The mounting position of -1 is used as a fulcrum of the plate-shaped fixing portion 9b to support the load transmitted from the curved portion 9a, and the flange portion 6b of the outer circumferential flexible water blocking member 6 and the flange of the inner circumferential flexible water blocking member 7 are supported. The load acting on the portion 7b is avoided or reduced, and the local compressive displacement generated in the flange portion 6b and the flange portion 7b is suppressed. By this method, it is possible to provide a joint having higher pressure resistance and improved water-stopping property and fixing property.

The rigid body 30 may be integrally welded to the frame body 24 or the fixing portion 9b or may be inserted as a separate body.

FIG. 9 is a sectional view showing a modification of the embodiment shown in FIG. In the embodiment shown in FIG. 9, the anchor members 4, 4 '
Does not have a flange portion to the outer peripheral side, and the water-permeable sheet 22 for preventing intrusion of earth and sand has a bolt 34 through a pressing plate 33 into a screw hole (not shown) formed in the end side of the anchor member. By fixing, the joint material 19 is mounted so as to be located on the outer peripheral side. That is, the rising portion 24c in FIG. 8 is omitted.

Further, in this embodiment, the proof member 2
1 is a rod-shaped member 13 and a plate-shaped member 1 in the embodiment of FIG.
4 (FIGS. 3 and 4), the curved portion 21a is made of a strip steel plate having a U-shaped cross section, and the anchor portion 21b is the curved portion 21a, as shown in the perspective view of FIG. The plate-shaped member is integrally formed with the member forming the.
When the load bearing member 21 is formed by integral molding as described above, the load bearing member 21 can be easily manufactured by bending a steel plate, so that processing and assembly of a joint are simple. Reference numeral 21c in FIG. 10 is a through hole into which the bolt 10 is inserted.

As a modification of the embodiment of FIG. 9, FIG.
As shown in FIG. 10B and FIG.
The curved portion 21a is formed of a strip-shaped steel plate having a U-shaped cross section, and the anchor portion 21b is formed of a plate member that is a separate body, and these two members are fixed to each other by bolting or welding. You may

2 and 9, the outer end portions 9c of the load bearing members 9 and 21 and the outer end edges of the anchoring portions 9b and 21b of the load bearing members 9 and 21 are both outer peripheral flexible. It exists in a state of being covered by the water member 6 and the inner circumference flexible water blocking member 7, and this structure is intended to prevent corrosion of the anchored portion 9b of the load bearing member 9 and the anchored portion 21b of the load bearing member 21. Although effective and preferable, when such corrosion of the anchored portions 9b, 21b does not pose a problem, the outer end edges of the anchored portions 9b, 21b do not necessarily have the outer peripheral flexible water blocking member 6 and the inner peripheral edge. It does not have to exist inside the outer end edge of the flexible water blocking member 7. For example, as shown in FIG. 8, the outer end edge 9c of the proof member 9 exceeds the outer end edge 6d of the outer peripheral flexible water blocking member 6. May be extended.

Further, the constricted portions of the outer circumferential flexible water blocking member 6, the inner circumferential flexible water blocking member 7 and the proof member 9 are not limited to those having a U-shaped cross section as shown in each of the above embodiments, but joints may be used. In the case of displacement, in order to improve the displacement followability of the flexible water blocking member and reduce the displacement resistance of the joint anchoring portion, for example, two M-shaped cross-sections may be provided that bulge inward. However, an arbitrary shape such as a bellows shape having three or more bulging portions can be selected.

Further, the joint portion other than the essential constituent elements of the present invention can be variously modified in addition to those described in the above embodiments.

For example, as for the frame 24, in addition to the one shown in FIG. 8, a part of the protective material 17 may cover the inner peripheral side end surface of the frame 24. With this configuration, the inner peripheral side end surface of the frame body 24 is not directly exposed to the high-humidity atmosphere in the underground structure (for example, an underdrain), and the durability of the joint can be improved. Further, a configuration in which the end surface portion 24b of FIG. 8 is removed is also possible.

Further, instead of assembling and constructing the entire joint by on-site construction, it is also possible to eliminate the frame body 4 by taking a method such as assembling the underground structures 1, 1'into one unit at the factory.

In each of the above embodiments, the protective material 1
Although No. 7 is used, it is needless to say that the earth and sand intrusion prevention structure in the joint of the underground structure according to the present invention can be applied to the joint not using the protective material.

FIG. 11 is a sectional view showing still another modification of the embodiment shown in FIG. In this embodiment, the vertical portion 36a of the anchoring member 36 having an L-shaped cross section is arranged so as to be interposed between the outer end edge 6d of the outer circumferential flexible water blocking member 6 and the end face of the step portion 3. The function of the vertical portion 36a is the same as that of the rigid body 30 in the embodiment shown in FIG.

FIG. 12 is a sectional view showing a modification of the embodiment shown in FIG. In this embodiment, the vertical portion 9d of the anchoring portion 9b of the proof member 9 having an L-shaped cross section is arranged so as to be interposed between the outer end edge 6d of the outer peripheral flexible water blocking member 6 and the end face of the step portion 3. ing. The function of this vertical portion 9d is the same as that of the rigid body 30 in the embodiment of FIG. When the vertical portion 36a of FIG. 11 and the vertical portion 9d of FIG. 12 are arranged, it is more effective to fix them in two stages as shown in FIG. 8 when fixing.

Next, the function common to the various joints 2 to which the structure for preventing intrusion of sediment in the joint of the underground structure according to the present invention shown in FIGS. 2 to 12 is applied will be described. Even if the underground structures 1, 1 ′ are buried in the ground where groundwater pressure acts, leakage of water into the underground structures 1, 1 ′ is prevented by the water-blocking outer peripheral flexible water blocking member 6 connecting them. It Moreover, the constricted portion 6a at the center of the outer peripheral flexible water blocking member 6
Since the rod-shaped member 13 or the plate-shaped curved portions 21a are arranged at regular intervals on the inner surface of the structure to support the outer peripheral flexible waterproof member 6, the inner peripheral flexible waterproof member 7 and the outer peripheral flexible waterproof member 7 are supported. The water member 6 hardly bulges and deforms inward of the underground structures 1, 1 ′.

Further, the ground subsidence causes uneven construction 1,
When 1 ′ is relatively displaced relatively, the constricted portion 6a of the outer circumferential flexible water blocking member 6 extends and absorbs the displacement of the underground structure 1, 1 ′. Further, since the outer circumferential flexible water blocking member 6 has the constricted portion 6a having a U-shaped cross section, the outer circumferential flexible water blocking member 6 is associated with the relative displacement of the underground structures 1, 1'of the outer circumferential flexible water blocking member 6. The expansion of 6 itself is small, and almost no internal stress is generated in the outer peripheral flexible water blocking member 6 which impairs the durability, and the displacement resistance of the joint is very small.

A protective material is provided in the space formed between the step portion 3 and the inner flexible water blocking member 7, and the inner surface of the protective material is the constriction of the inner flexible water blocking member 7. Since the inner flexible water blocking member 7 is in contact with the side surface of the portion 7a, the protective material exerts an effect of preventing the underground structure 1 from bulging and deforming in the axial direction even when a large external water pressure is applied. .

Further, since the protective material is fixed to the push plate 12 by the bolt 18, it can be easily detached from the inside of the underground structure 1 with a tool such as a torque wrench if necessary.

Further, a water-permeable sheet 22 for preventing sediment intrusion
Since it is mounted so as to be located on the outer peripheral surface side of the joint material 19, even if expansion and contraction of the joint portion occurs due to an earthquake, there is no intrusion of earth and sand into the constricted portion of the outer peripheral flexible waterproofing member 6, and repeated expansion and contraction is hindered. It is a highly earthquake-resistant joint that can be absorbed without any damage. Furthermore, the joint is relatively displaced due to ground fluctuations, etc., and a gap is created between the joint material and the outer peripheral flexible water blocking member, and the surrounding earth and sand enter the constricted part of the inner peripheral flexible water blocking member through this gap. Can be prevented.

Next, the structure for preventing the intrusion of earth and sand in the joint of the underground structure according to the present invention is shown in FIG.
Another embodiment applied to the joint 2 of 'will be described. FIG.
As described above, the end faces that are the opposite ends of the underdrain 1 and 1'which are a pair of opposing underground structures are connected by the joint 2 of the underground structure.

FIG. 13 shows a cross section taken along the line I--I in FIG. 1. Unlike FIG. 2, FIG. 13 shows a cross section in which the cutting positions are shifted from side to side. Although the reference symbols are omitted on the left and right, the explanation will be made assuming that they are left and right respectively.

In FIG. 13, the joint 4 of this underground structure
2 is a cylindrical frame in which step portions 43, 43 'are formed on the inner peripheral surface side peripheral edge of the opposing ends of the underground constructions 41, 41' whose cross section is formed by casting concrete. The bodies 44 and 44 'are fixed along the step portions 43 and 43'.

The frame members 44, 44 'are provided with end face portions 44a, 44'.
It has a step portion including the outer peripheral annular portions 44b and 44'b. In addition, reference numerals 44c and 44'c are culverts 41 and 4
An inner peripheral annular portion having a diameter substantially equal to that of the inner periphery of 1 ', reference numeral 44d,
Reference numeral 44'd is a flange portion protruding outward from the outer peripheral annular portions 44b, 44'b, and is a flange portion for fixing a water-permeable sheet 58 for preventing sediment intrusion, which will be described later.

Shape of frame 44 'and underground structure 41'
Since the mounting structure is exactly the same as that of the frame body 44, the description of the frame body 44 'and the like will be omitted as occasion demands by adding a number with a dash added to the reference numeral used for the frame body 44 and the like.

The outer peripheral annular portion 44 of the frame bodies 44, 44 '
A flexible water blocking member 46 made of rubber, synthetic resin or the like and formed in a short tube shape is disposed between b and 44'b. The flexible water blocking member 46 has an annular constricted portion 46a having a substantially U-shaped cross section at the center thereof, and the outer periphery of the constricted portion 46a is an annular recessed portion 46c opening outward. .

An anchoring flange portion 46b is integrally formed which extends from both sides of the constricted portion 46a and is in close contact with the outer peripheral annular portion 44b of the frame body 44. Reference numeral 46e is a reinforcing cloth against external pressure, which is suitable for receiving a high external pressure, and is flexible along the inner peripheral surface of the flexible water blocking member 46.
It is attached so as to be integral with or covered by 6. The reinforcing cloth 46e may be incorporated in the flexible water blocking member 46 in some cases. Needless to say, the reinforcing cloth 46e is not necessary when the external pressure is small. Further, the reinforcing cloth 46e is provided only in the portion including the anchoring flange portion 46b or the vicinity thereof so that the flexible water blocking member 46 is not damaged from the portion of the bolt insertion hole 46f provided in the anchoring flange portion 46b. You may stay.

The anchoring flange portions 46b provided on both sides of the flexible water blocking member 46 and extending in the axial direction (horizontal direction in the drawing) have bolts 45 inserted through this portion and nuts 47.
The nut 47 and the anchoring flange 46 are screwed together.
By interposing a push plate 48 between it and b and tightening a nut 47, it is brought into close contact with the inner peripheral surface of the outer peripheral annular portion 44b of the frame body 44, and is fixed in a watertight manner. Although the frame 44 is provided with the inner peripheral flange portion 44c and the flange portion 44d in this embodiment, the flange portion 44c may not be provided. The material of the flexible water blocking member 46 may be the same as the material in the first embodiment described above.

A bolt 45 is attached to the annular push plate 48 in the outer peripheral direction.
Through holes 48a are provided at appropriate intervals. Also, the push plate 4
Threaded portions 48b are provided on one surface of the plate 8 at appropriate intervals. In this embodiment, the threaded portion 48b is formed by welding the bulky bolt, but the invention is not limited to this, and the pressing plate 4 is not limited thereto.
A protective material 49, which will be described later, such as one directly screwed to 8,
Anything can be used as long as it can be fastened to the push plate 48 by screwing the bolt 50.

Further, the threaded portion 48b is provided with the protective material 49 by the bolt 5
The number of bolts is less than that of the normal bolt insertion holes 48a because it is to be fastened with 0 and a large external force does not act.

A protective member 49 is provided in the space 51 formed between the frame body 44 and the flexible water blocking member 46. The protective material 49 includes a pressing plate 48 on the outer peripheral end surface 49a and a screwing portion 48b.
Also, a groove 52 for accommodating the nut 47 is provided, and a groove 53 for accommodating the head of the bolt 50 is provided on the inner peripheral end surface 49b. Concave groove 54 provided on the outer surface 49c of the protective material 49
Is provided in order to reduce the weight of the protective material 49, and there is no problem even if it is formed as a hollow part or as an actual one without the groove 54. Further, the protective material 49 is provided with a bolt insertion hole 55 for inserting the bolt 50.

In the protective material 49, the outer peripheral end surface 49a contacts the anchoring flange 46b of the flexible water blocking member 46, the outer surface 49c contacts the end surface portion 44a of the frame body 44, and the inner surface 49d contacts the flexible water blocking member. It is in contact with the side surface 46d of the constricted portion 46a of 46 and is indirectly fixed to the outer peripheral annular portion 44b of the frame body 44. That is, the protective material 49 is pushed by the bolt 50 into the push plate 48.
The push plate 48 is indirectly fixed to the outer peripheral annular portion 44b by being fixed to the outer peripheral annular portion 44b of the frame body 44 by the fastening bolt 45 and the nut 47.

In this embodiment, the grooves 52, 53 and 54 are
Have been shown to be continuous in the circumferential direction, but are not limited thereto, and may be discontinuous.

The protective material 49 may be made of rubber, synthetic resin, metal, hard foam or the like.

Incidentally, it is preferable that the pressing plate 48 and the protective material 49 be of a plurality of circumferentially divided types in consideration of handling and the like.

Reference numeral 56 is an anchor whose one end is welded to the head of the fastening bolt 45 and which is embedded in the axial direction of the underground structure 41.

The anchor 56 is used to more firmly fix the frame body 44 to the end of the underground structure 41.
As long as it meets the purpose, it is not limited to the one in the embodiment, and the connecting method with the frame body 44, the shape and the like are arbitrary.

Reference numeral 57 indicates the recess 46 of the flexible water blocking member 46.
Prevents dirt and sand from entering c, and underground structures 41, 41 '
An annular joint material made of sponge such as rubber or synthetic resin for allowing relative movement between them to some extent.

As the joint material 57, the same elastic material as in the first embodiment is used. The cross-sectional shape of the joint material 57 may follow the U-shaped internal shape as in the first embodiment, but a slit is formed at the center of the cross section or a sponge body divided into several vertically is used as the filling material. As a result, it is possible to further improve the followability to the U-shaped shape displacement when the displacement progresses.

In this embodiment, the intrusion of earth and sand into the respective ends of the two underground structures 41 and 41 'which are located in the joint space on the outer peripheral surface side of the joint material 57 and contact the joint material 57 so as to form an annular shape. A waterproof water-permeable sheet 58 is attached.

The water-permeable sheet 58 for preventing the intrusion of earth and sand is
Similar to the first embodiment, for example, it is constituted by a corrosion-resistant and water-permeable synthetic woven fabric or a non-woven fabric or a combination of these with a corrosion-resistant wire mesh or the like as a core material, and has a function of allowing water in the soil to permeate but trapping earth and sand. Water-permeable sheet 58 for preventing sediment intrusion
Is a bolt insertion hole (not shown) whose anchoring portion 58a is formed in the flange portion 44d of the frame body 44 through the pressing plate 64.
The bolts 68 and the nuts 69 inserted in the anchors are anchored to the facing surfaces of the flange portions 44d and 44'd of the frame body 44 so as to be fixed to the opposing ends of the underground structures 41 and 41 '. Further, a water-permeable sheet 58 for preventing intrusion of sediment
Is provided with a U-shaped cross section to provide an expansion and contraction function, and even if a gap is generated between the end surface of the underground structure and the joint material 57 due to the relative displacement between the underground structures 41 and 41 ', this gap It extends so as to cover, and captures the earth and sand that are going to pass through the gap.

As described above, in this embodiment, an elastic body (rubber or sponge body) having an appropriate repulsive force is formed by filling the inside of the U-shape and further projecting a certain height above it.
A joint material 57 made of is attached, and a water-permeable sheet 58 for preventing intrusion of earth and sand is disposed on the outer peripheral surface of the joint member 57, the end portion of which is pressed and fixed between the frame body 44 and the flexible water blocking member 46.

The water-permeable sheet 58 for preventing the intrusion of earth and sand is
Protects and stabilizes the joint material 57 from the outside when the displacement progresses,
Even if the earth and sand should enter between the joint material 57 inside the U-shape and the flexible water blocking member 46 when the displacement progresses, it can be prevented. The corrosion-resistant and water-permeable synthetic fiber may be the same as in Example 1.

Next, the function of the joint 42 of the underground structure having the above structure will be described. Even if the underground structures 41, 41 ′ are buried in the ground where groundwater pressure acts, the underground water structures 41, 4 are connected by the flexible water-stop member 46 for water stopping that connects them.
Water leakage into 1'is prevented.

In addition, the ground subsidence causes uneven settlement and
When 1, 41 'are largely displaced relative to each other, the flexible water blocking member 46
The constricted portion 46a extends to absorb the displacement of the underground structures 41, 41 '. In addition, since the flexible water blocking member 46 has the constricted portion 46a having a U-shaped cross section, the flexible water blocking member 46 itself due to relative displacement of the underground structures 41, 41 'of the flexible water blocking member 46 is Almost no internal stress is generated in the flexible water blocking member 46 that has a small elongation and impairs durability, and the displacement resistance force in the joint is very small.

Further, a water-permeable sheet 58 for preventing intrusion of earth and sand
Since the joint is mounted so as to be located on the outer peripheral surface side of the joint material 57, when the joint expands due to the expansion and contraction motion due to an earthquake, the intrusion of earth and sand into the gap formed in the annular portion 46c of the constricted portion of the flexible water blocking member 46. It is a seismic resistant joint that is highly safe and can absorb the repeated earthquake motion without any hindrance. Further, even if a gap is formed between the joint material 57 and the flexible water blocking member 46 when the relative displacement of the underground structures 41, 41 ′ in the axial direction progresses due to crustal movement, etc. Can be prevented from entering the inside of the constricted portion of the flexible water blocking member 46.

A protective material 49 is provided in the space 51 formed between the frame body 44 and the flexible water blocking member 46.
The inner side surface 49d of 9 is the constricted portion 46a of the flexible water blocking member 46.
Since it is in contact with the side surface 46d of the flexible waterproofing member 46, even if a large external water pressure acts, the protective material 49 prevents the underground structure 41 from bulging and deforming in the axial direction, and the external water pressure Supported.

Further, since the protective material 49 is constructed so that the side surface 46d of the flexible water blocking member 46 covers the nut 47, the pressing plate 48, the screwed portion 48b and the like with the protective material 49, it is protected from damage. Can be prevented.

The protective material 49 is an outer peripheral annular portion 44b of the frame body 44.
Since it is fixed by the bolt 50 to the push plate 48 fixed to, it can be easily detached from the inside of the underground structure 41 with a tool such as a torque wrench if necessary.

Thus, in FIG. 13, the joint material 57 is
16 is attached to the ends of the two underground constructions 41, 41 'that are located on the outer peripheral surface side and contact the joint material 57 so as to form an annular shape. As shown in FIG. 5, the joint material 57 contracts due to the relative displacement between the underground structures 41 and 41 ′ and the increase in pressure due to the deepening of the buried position of the underground structures 41 and 41 ′, and the joint material 57 contracts.
Even if a gap 59 is formed between the end surface of the underground structure 41, 41 ′, the earth and sand 70 which is about to enter is captured by the water and sand permeable water-permeable sheet 58, and the U inside of the flexible water blocking member 46 is captured. Never break into. Therefore, the displacement of the flexible water blocking member 46 is not restricted by the accumulation and solidification of the invading sediment, and the flexible water blocking member 46 can freely expand and contract following the relative displacement between the underground structures 41 and 41 '. Further, unlike the conventional case, it is not necessary to receive the earth and sand pressure and the external water pressure only by the flexible water blocking member, and the burden on the flexible water blocking member 46 can be reduced. The amount of reinforcing material added can be reduced. This can contribute to smooth absorption by reducing the resistance of displacement in all directions including expansion and contraction due to earthquake motion and uneven settlement.

Further, in the joint shown in FIG. 13, the displacement of the joint is absorbed by the shape change (straightening) of the flexible water blocking member 46, so that the joint conventionally used (for example, FIG. 19). The fixing box is installed at the end of the opposing underground structure like this, and the fixed length of the end of the load-bearing bar is accommodated in this fixing box and the displacement is not absorbed by the axial movement of this accommodation section. Therefore, the fixing box becomes unnecessary, and the cost can be significantly reduced.

Further, since there are almost no places where members are constructed or assembled by welding, and there are no unstable places where the quality of welding significantly affects the performance, a highly reliable joint can be provided.

Next, FIG. 14 shows a structure for preventing intrusion of sediment in a joint of an underground structure according to the present invention, which is basically the same as the joint 42 of the underground structure shown in FIG.
It is an example applied to an underground structure to which some new members are added.

Similar to FIG. 13, FIG. 14 is a cross-sectional view in which the cutting positions are left and right shifted, but in reality it is left-right symmetric, and therefore the symbols are partly left and right, but for the sake of explanation, they are left and right respectively. The explanation will be given assuming that the two are symmetrical.

In this embodiment, the inner circumference of the embodiment shown in FIG. 13 straddles the inner circumference annular portions 44c and 44'c and is made of an elastic material such as rubber or synthetic resin into a short cylindrical shape. Both ends of the flexible water blocking member 60 are provided, and the inner flexible water blocking member 6 is provided.
0 is watertightly fixed to the inner peripheral surfaces of the inner peripheral annular portions 44c and 44'c.

Both ends of the inner circumferential flexible water blocking member 60 are anchored and anchored bolts 61, 61 'provided through the inner circumferential annular portions 44c, 44'c, and nuts 62, 62'.
Inner peripheral annular portions 44c, 44 with the pressing plates 63, 63 'interposed
It is fastened to'c. In the figure, reference numerals 44f and 44'f
Is a flange portion protruding from one end of the inner peripheral annular portion 44c, 44'c toward the inside of the underground structure 41, 41 '.

Since the other points are similar to those of the embodiment shown in FIG. 13, the parts corresponding to the members shown in FIG. 13 are designated by the same reference numerals and the detailed description thereof will be omitted.

This embodiment is equivalent to the embodiment shown in FIG. 13 with the addition of the inner circumference flexible water blocking member 60. Therefore, the presence of this inner circumference flexible water blocking member 60 prevents the water stoppage. In addition to being more reliable, the sand and the like flowing in the underground structures 41, 41 ′ have a space 7 inside the underground structures 41, 41 ′.
It does not impede the followability of deformation such as expansion and contraction of the joint 42 of the underground structure.

Further, the inner circumferential flexible water blocking member 60 can reduce the head loss due to the turbulent flow of water or the like flowing in the underground structures 41, 41 'as much as possible.

Although the protective material 49 is fixed to the pressing plate 48 with the bolts 50 in the second embodiment shown above, the present invention is not limited to this, and as shown in FIG. As shown in FIG. 15B, a support body 65 such as a rod body, a plate body or a plate piece is provided on the inner peripheral side end face of the end face plate 44a of the frame body 44, and a protective material 49 is fitted between them. 15C, the protective material 49 also serves as a pressing plate as shown in FIG. 15C, and reference numeral 66 in the figure prevents accumulation of dust, earth and sand, etc., and prevents water flow resistance. Reference numeral 67 is a support member such as a rod, a plate piece, or a long plate that prevents the filler from coming off, and is a protective member with an optional interval. 49 is integrally provided. The support member 67 may be fixed to the end surface portion 44a of the frame body 44.

The material of the flexible water blocking member 46 is rubber.
A synthetic resin or a combination of a synthetic resin and a reinforcing cloth is preferable. Further, the inner circumferential flexible water blocking member 60 is not limited to the right cylindrical shape, but may have various shapes such as a bellows shape and a cylindrical body having a hollow portion in the circumferential direction.

Specific examples of the corrosion-resistant and water-permeable synthetic fiber or the non-woven fabric are the same as those in the above-mentioned embodiments.

Next, the function of the joint 42 of the above-constructed underground structure will be described. Even if the underground structures 41, 41 ′ are buried in the ground where groundwater pressure acts, the underground water structures 41, 4 are connected by the flexible water-stop member 46 for water stopping that connects them.
Water leakage into 1'is prevented.

In addition, the ground subsided due to uneven settlement
When 1, 41 'are largely displaced relative to each other, the flexible water blocking member 46
The constricted portion 46a extends to absorb the displacement of the underground structures 41, 41 '.

Due to the occurrence of a large relative displacement between the underground structures 41 and 41 ', or the deepening of the buried position of the underground structures 41 and 41', the joint is opened and the joint material 57 and the underground structures 41 and 41 'are opened. Even if an earth and sand accompanied by earth pressure tries to invade into the joint through this opening, the earth and sand are caught by the water and sand permeable water-permeable sheet 58 mounted on the outer peripheral side of the joint material 57, and the outer periphery is flexible. Water stop member 46
The space 64 formed by the constricted portion 46a is prevented from entering and accumulating and solidifying.

Example 1 shown in FIGS. 2 to 8 and
In Example 2 shown in FIG. 13 to FIG. 16, a water-permeable sheet for preventing intrusion of earth and sand is fixed with bolts or the like to the axial end portion side of the flange portion rising radially outward from the opposite end portions of the anchor portion. However, the flange portion may be fixed to the opposite side.

In Examples 1, 2 and their modifications, examples were shown in which the structure for preventing intrusion of sediment in the joint of an underground structure according to the present invention was applied to the connection of an underground structure made of concrete. The present invention is not limited to underground constructions made of materials, but may be applied to joints of underground constructions made of other materials. In the case where the underground structure is made of steel, the water-permeable sheet for preventing intrusion of sediment may be directly fixed to the end of the underground structure such as the end face of the underground structure with bolts and nuts instead of the frame.

The sectional shape of the underground structure is not limited to the circular shape, and may be any of an elliptical shape, a quadrangular shape, and other polygonal shapes. Further, the underground building may be an integral product, or may be constructed by assembling divided members. This joint can be applied not only to an underground structure constructed by an open-cutting method but also to an underground structure constructed by a non-excavated method such as a shield method.

[0124]

As described above, according to the present invention, in the joint space between the underground constructions on the outer peripheral side of the flexible water blocking member, a flexible material which allows water to pass therethrough without allowing sand and sand to pass therethrough. By mounting a water-permeable sheet for preventing sand intrusion formed in a short tubular shape across each end of the underground structure, earth and sand enter the constricted part of the flexible water blocking member, and it accumulates and solidifies. It is possible to prevent the functional failure of the flexible water blocking member.

Further, since the flexible water blocking member may mainly share the pressure resistance function against the external water pressure, the load on the flexible water blocking member is reduced, and the amount of the reinforcing material added to the flexible water blocking member is minimized. You can stop to the limit. This contributes to maintaining good displacement followability of the flexible water blocking member against relative displacement between underground structures.

Even if the earth and sand try to invade the constricted portion of the flexible water blocking member, the earth and sand preventive sheet is attached to the outer peripheral side of the joint material. Since it is captured by the elastic sheet, the external pressure applied to the joint material from the earth and sand is reduced. Therefore, the withstand pressure of the joint material can be set lower, the flexibility of the joint material can be increased, and the degree of freedom in setting the joint material is increased.

Further, according to the present invention, since the sediment-permeable water-permeable sheet is mounted so as to be located on the outer peripheral side of the joint material, the joint material when the relative displacement of the underground structure in the axial direction progresses. The bulging deformation of the underground structure in the outside direction is suppressed as much as possible, and a gap is created between the joint material and the flexible water blocking member during the progress of such relative displacement. It is possible to prevent the flexible water blocking member from entering the constricted portion.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a joint of an underground building to which an earth and sand intrusion prevention structure is applied in the joint of the underground building according to the present invention.

FIG. 2 is a cross-sectional view showing one embodiment in which the earth and sand intrusion prevention structure for a joint of an underground structure according to the present invention is applied to the joint of the underground structure shown in FIG.

FIG. 3 is a partial perspective view showing one example of a load-bearing member.

FIG. 4 is a partial perspective view showing another example of the load-bearing member.

FIG. 5 is a view showing a method of fixing a rod-like member constituting a load-bearing member to a plate-like member.

FIG. 6 is a view showing another method of fixing a rod-like member constituting a load-bearing member to a plate-like member.

FIG. 7 is a perspective view of a push plate.

8 is a cross-sectional view showing an embodiment in which the structure for preventing intrusion of sediment in a joint of an underground structure according to the present invention is applied to a modification of the joint of the underground structure of FIG.

FIG. 9 is a cross-sectional view showing an embodiment in which the structure for preventing intrusion of sediment in a joint of an underground structure according to the present invention is applied to another modified example of the joint of the underdrain of FIG.

FIG. 10 is a perspective view of a load-bearing member used in the embodiment of FIG. 9;

11 is a cross-sectional view showing an example in which the structure for preventing intrusion of sediment in a joint of an underground structure according to the present invention is applied to another modification of the joint of the underground structure of FIG.

FIG. 12 is a cross-sectional view showing an example in which the structure for preventing intrusion of sediment in a joint of an underground structure according to the present invention is applied to another modification of the joint of the underground structure of FIG.

FIG. 13 is a cross-sectional view taken along the line I-I of the joint of the underground structure shown in FIG. 1.

FIG. 14 is a cross-sectional view of another underground structure joint to which the earth and sand intrusion prevention structure for the underground structure joint according to the present invention is applied.

FIG. 15 is a partially cutaway sectional view showing another example of the protective material used in the joint of the underground structure in the embodiment of FIG.
15A shows the case of the fitting type, and FIG. 15B shows the case of providing the support body on the inner peripheral side end surface of the frame body.
(C) shows the case where the protective material functions as a pressing plate.

FIG. 16 is a cross-sectional view showing the operation of the embodiment of FIG. 13 and is a view showing a state where joints between underground structures are opened.

FIG. 17 is a cross-sectional view showing an example of a situation where a large relative displacement occurs in a conventional underdrain joint.

FIG. 18 is a sectional view showing another example in which a conventional underdrain joint is buried at a high depth.

FIG. 19 is a cross-sectional view showing another example of a conventional underdrain joint.

[Explanation of symbols]

 1, 1'Underground structure 2 Joint 19 Joint material 22 Permeable sheet for preventing sediment intrusion

Claims (1)

(57) [Claims] 1. An underground construction comprising a pair of short-circuited flexible water blocking members made of an elastic material such as rubber or synthetic resin, which is installed across each end of the pair of opposed underground constructions. In the joint, the outer side of the joint material made of an elastic material such as rubber or synthetic resin placed in the joint space between the underground constructions on the outer peripheral side of the flexible water blocking member does not allow sand and sand to pass therethrough and allows water to pass A structure for preventing intrusion of sediment in a joint of an underground structure, characterized in that a water-permeable sheet for preventing intrusion of sediment formed of a flexible material in the form of a short tube is mounted across each end of the underground structure.