JPH07127083A - Sealing member for settling-burying tunnel - Google Patents

Abstract

PURPOSE:To allow large displacement of a settling-burying box without enlarging a cross-sectional area, improve stability when being compressed, facilitate molding, and prevent installing work from becoming large-scale. CONSTITUTION:The outside of pressure receiving rubber 10 having an almost rectangular cross-sectional shape is covered with sealing rubber 20 having a trapezoidal cross-sectional shape through a prescribed deformation allowable space 21. The pressure receiving rubber 10 is arranged along the opening edge of a settling-burying box 2, and the sealing rubber 20 is continuously arranged on the whole circumference of an opening part along the opening edge of the settling-burying box 2. The sealing rubber 20 is brought into pressure contact with a joining end surface of a joining mating side settling-burying box, and holds airtightness, and the pressure receiving rubber 10 receives joining pressure of the joining mating side settling-burying box.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing member for a submerged tunnel, which is interposed between joints of submerged boxes in a submerged tunnel method and maintains airtightness in the tunnel.

[0002]

2. Description of the Related Art In the submerged tunnel method, which is one of the methods for constructing a tunnel under the water such as a submarine tunnel, a submerged box of a predetermined length is formed on land in advance, and the submerged box is sequentially settled at a predetermined position and then joined. To do.

In order to maintain airtightness in the tunnel between the submerged boxes in such a submerged tunnel construction method, as shown in FIG.
A seal member having a cross-sectional view of an example thereof is interposed in the. The illustrated sealing member is called a so-called zina-type packing which is an example of an elastic packing, and a plate-shaped fastening portion 31 having a predetermined thickness is projected on both sides of a bottom portion of a trapezoidal main body 30 having a predetermined height. The cross-sectional shape is made of rubber having a predetermined hardness. Then, it is fastened to the joint end surface of the submerged box by a mounting bolt penetrating the fastening section 31, and is arranged continuously along the entire circumference along the opening edge of the submerged box.

During construction of the submerged box, the submerged boxes are pressed against each other by hydraulic pressure in a state where the edge of the submerged box with the packing and the edge of the submerged box with no packing correspond to each other. In a state of being compressed and elastically deformed by a predetermined amount, it becomes a state of being interposed between the end faces of both submerged boxes, and acts so as to maintain the airtightness inside. When the submerged boxes joined due to an earthquake or ground movement move (displace) relative to each other, the packing follows the movement of the submerged boxes and further elastically deforms or returns elastically to maintain an airtight state. To do. That is, the seal member absorbs the relative movement of the submerged box by its deformation, and maintains the airtight state.

[0005]

By the way, recently, it is desired to improve the earthquake resistance of a building, and a structure capable of permitting a larger displacement of the submerged box even in the submerged tunnel is required. . However, in the case of the gina type packing which is integrally formed of rubber and absorbs the displacement of the submerged box by its elastic deformation, as shown in the graph of the relationship between the deformation amount and the reaction force in the gina type packing as shown in FIG. Since the amount of deformation and the reaction force are approximately proportional to each other, in order to increase the displacement allowable amount of the submerged box, increase the amount of compression when submerging the submerged box and make the difference between the amount of deformation that produces the minimum water reaction force. It is necessary to make it large, and for that reason, the thickness and volume must be made larger.

However, when the thickness and volume are increased to set the compression amount at the time of the submerged box joining work in this way, the shape ratio (the pressure receiving area divided by the free area is expressed at the time of the submerged box joining work. However, there is a problem in that the influence of defects during manufacturing is likely to occur because the shear stress acting on the slab becomes larger and the shear stress acting on the sunk box further increases when the sunk box is displaced in the direction in which it approaches. Also, since the cross-sectional area becomes large (thick), the stability during compression is poor, the heat during vulcanization is difficult to be evenly transferred during manufacturing, and this easily causes defects. There is also a problem that it becomes a large scale. Further, a seal nose 32 made of soft rubber having a triangular cross-section is projected on the upper surface. However, since the rubber is generally incompressible, the seal nose 32 is stuck in the main body when it is excessively compressed. It also has a fear of causing a stress, which causes the main body portion to rupture.

The increase in internal shear stress can be prevented by inserting and strengthening an iron plate or the like in a layered manner in the thickness direction (compression direction). In that case, a graph of the relationship between the amount of deformation and the reaction force is shown. As shown in FIG. 10, the proportional constant becomes large, and the amount of deformation for obtaining the reaction force necessary for stopping water is small.
In particular, the displacement allowable range in the direction in which the submerged box is separated becomes extremely narrow.

The present invention has been made in view of the above problems, and can allow a large displacement of the burial box without increasing the cross-sectional area, has good stability when compressed, and is easy to mold. Moreover, it is an object of the present invention to provide a sealing member for a submerged tunnel that does not require a large amount of mounting work.

[0009]

A seal member for a submerged tunnel of the present invention which achieves the above object is interposed between the joint end faces of each submerged box in the submerged tunnel construction method to maintain airtightness in the tunnel. And a pressure receiving member that is formed at a predetermined height by an elastic material, is disposed along the opening edge of the joint end surface of the submerged box, and receives the joint pressure of the submerged box on the other side of the joint, and the pressure receiving member by the elastic material. A seal member which is formed higher by a predetermined amount and which is continuously disposed along the entire circumference of the opening along the opening edge and is pressed against the joining end surface of the submerged box on the joining partner side to maintain airtightness. It is characterized by

[0010]

When the submerged box is joined, the seal member comes into contact with the joint end surface of the submerged box on the other side of the joint before the pressure receiving member and elastically deforms to obtain the reaction force necessary for maintaining the airtightness, and the joint pressure higher than a predetermined value is applied. The pressure receiving member receives the seal member as it elastically deforms and escapes. The airtightness is maintained by the seal member being pressed against the joint end surface of the submerged box on the other side of the joint, and the displacement in the direction in which the joint submerged boxes approach each other is absorbed by the compressive deformation of the pressure receiving member, and the submerged joints are separated from each other. The seal member elastically returns and follows the displacement in the direction.

[0011]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view of a submerged tunnel gasket which is an embodiment of the submerged tunnel seal member according to the present invention.

The illustrated submerged tunnel gasket 1 is composed of a pressure receiving rubber 10 as a pressure receiving member and a seal rubber 20 as a sealing member that covers the periphery thereof.

The pressure-receiving rubber 10 is made of a rubber having a predetermined hardness and has a substantially square cross-section and is formed in an appropriate length in the direction (longitudinal direction) orthogonal to the plane of the drawing for easy mounting work. Inside, there are three reinforcing iron plates 11 of a predetermined thickness.
Are inserted at predetermined intervals in the thickness direction. A mounting hole 12 is vertically provided at the center in the width direction, and the mounting hole 12 is provided with a hole having a depth reaching the upper surface of the reinforcing iron plate 11 of the lowermost layer. The mounting holes 12 are provided at predetermined intervals in the length direction of the pressure receiving rubber 10.

The seal rubber 20 is provided with a pressure receiving rubber storage space 21 for accommodating the pressure receiving rubber 10 on the bottom surface (mounting surface) side. By covering the pressure receiving rubber 10 with its side surface and upper surface excluding the bottom surface. The cross-sectional shape that can be covered is made of rubber having a predetermined hardness. In the direction orthogonal to the paper surface, it is integrally formed in a ring shape corresponding to the opening of the submerged box to be attached, which is formed by forming a rod-shaped material of the cross-sectional shape by extrusion molding or laminating Is made by joining the end faces to each other according to the opening shape of the submerged box.

The outer shape of the seal rubber 20 is a trapezoid whose height is about twice the thickness of the pressure receiving rubber 10 and whose width on the upper surface is narrower than the width on the mounting surface side by a predetermined amount. The end portions are laterally extended in a plate shape having a predetermined thickness to form a mounting portion 22. The mounting portion 22 is reinforced by reinforcing fibers that are layered in the thickness direction, and a mounting hole 22A penetrating in the thickness direction is formed in the mounting portion 22. The mounting hole 22A extends in the longitudinal direction of the seal rubber 20. It is arranged at a predetermined interval. Seal noses 23 each having a triangular cross section are provided at predetermined heights near both ends in the width direction of the upper surface.

The pressure receiving rubber accommodation space 21 is the accommodation space 2
It is a gap when the pressure receiving rubber 10 is accommodated in the inside 1 when the pressure receiving rubber 10 is covered with the seal rubber 20.

The outer shape and the pressure receiving rubber storage space 21 as described above.
Due to this shape, the seal rubber 20 has a substantially uniform thickness as a whole.

The submerged tunnel gasket 1 constructed as described above has a conceptual perspective view shown in FIG.
First, the pressure-receiving rubber 10 is attached to the connection end surface 2A of the submerged box 2 with the hexagon socket head cap bolt 13 (not shown in FIG. 3), and then the sealing rubber 20 is covered with the pressure-receiving rubber 10 and the sealing rubber 20 is attached thereto (see FIG. 3). (Not shown). Here, the pressure-receiving rubber 10 is attached along the opening edge 2B of the submerged box, but it is not necessarily required to be attached continuously, and may be spaced at a range that can withstand the joining pressure of the submerged box. is there. On the other hand, the seal rubber 20
Must be integrally molded so as to continuously surround the periphery of the opening along the opening edge 2B of the submerged box. This is because the seal rubber 20 functions to maintain airtightness, and the pressure receiving rubber 10 only acts to receive the pressure contact force of the submerged box, but does not contribute to maintaining airtightness.

Next, the operation of the submerged tunnel gasket 1 having the above construction will be described. At the time of construction of the submerged box, the end face of the submerged box 3 (not shown in FIG. 3) not fitted with the submerged tunnel gasket is hydraulically pressed to the end of the submerged box 2 to which the submerged tunnel gasket 1 is attached. As a result of this pressure, the seal rubber 20 is pushed to its side plate portion 20 as shown in FIG.
A is bent and deformed outward, and the inner surface (lower surface) of the upper plate portion 20B abuts the upper surface of the pressure receiving rubber 10 so that the upper plate portion 20B rides on the pressure receiving rubber 10.
Receives pressure. That is, the upper plate portion 20 of the seal rubber 20
Until the lower surface of B reaches the upper surface of the pressure receiving rubber 10, it is interposed between the submerged boxes 2 and 3 while pressing the end surface of the submerged box 3 by the reaction force due to the bending deformation of the side plate portion 20A, thereby ensuring the airtightness. Hold. On the other hand, the lower surface of the upper plate portion 20B is the pressure receiving rubber 1
After reaching the upper surface of 0, the pressure receiving rubber 10 receives the pressure contact force of the submerged box and suppresses further deformation of the seal rubber 20.

The relationship between the amount of deformation and the reaction force of the submerged tunnel gasket 1 is shown in the graph of FIG. That is, the submerged tunnel gasket 1 as a whole exhibits a characteristic in which the amount of deformation of the seal rubber 20-reaction force characteristic and the amount of deformation of the pressure receiving rubber 10-reaction force characteristic are combined, and in the region where only the seal rubber 20 is deformed, When the amount of deformation is small, the reaction force increases in proportion to the amount of deformation, but thereafter the reaction force becomes stable and becomes stable regardless of the increase in the amount of deformation, and the lower surface of the upper plate portion 20B becomes the upper surface of the pressure receiving rubber 10. After the contact, the reaction force increases in proportion to the deformation amount of the pressure receiving rubber 10. In addition, in FIG. 4, the height of the pressure receiving rubber is 1
The characteristics are shown for the case where the width is 00 mm, the width is 150 mm, and the height of the sealing rubber up to the upper surface is 200 mm.

As described above, the deformation amount-reaction force characteristics of the seal rubber 20 are set so that the seal rubber 20 alone can obtain the reaction force necessary for stopping water in a wide deformation range, and the joining pressure at the time of construction is the pressure received. By setting the thicknesses of the pressure-receiving rubber 10 and the seal rubber 20 so that the rubber 10 receives and has a predetermined reaction force, the displacement in the direction in which the submersible boxes are separated from each other causes the seal rubber 20 to move against the water required for stopping water. Displacement in the direction in which the submerged boxes are close to each other is allowable within the area where the force is maintained, and the pressure-receiving rubber 10
Can be tolerated until destruction. That is, since the seal rubber 20 that is deformed by the reaction force necessary for stopping water and the pressure receiving rubber 10 that maintains the gap between the submerged boxes under pressure are combined, a large displacement of the submerged box can be allowed and absorbed. It is a thing.

Although the seal rubber 20 is formed so as to cover the pressure receiving rubber 10 in the above-described embodiment, the present invention is not limited to this structure, and the pressure receiving rubber 10 can be provided if the mounting space is allowed. The seal rubber 20 may be arranged side by side.

Further, it is desired that the shape of the seal rubber 20 is set so that the reaction force increases remarkably in the initial stage of the deformation and thereafter the reaction force becomes constant in a wide range as much as possible. It can be said that the inverted U type shown in FIG. 5 and the inverted V type shown in FIG. 5 have more preferable characteristics than the O type shown in FIG. 7, but the desired characteristics may be set by appropriately changing the thickness and shape. It is a thing.

[0024]

As described above, according to the seal member for the submerged tunnel of the present invention, the pressure receiving member which receives the joining pressure of the submerged box on the other side of the joint and the end face of the joint of the submerged box on the other side of the joint are pressed. Since the seal member is configured to have a predetermined amount higher than the pressure receiving member that keeps the airtightness, the seal member holds the airtightness in the submerged box, and the joining pressure of the submerged box is elastically deformed by the seal member to the pressure receiving member. After the contact, the pressure receiving member receives it. For this reason, it is possible to widen the deformation range of the seal member that can obtain a reaction force capable of stopping water without increasing the cross-sectional area, can follow a large displacement of the submerged box, and can also withstand a large joining pressure of the submerged box. Can withstand stable.

Further, since the pressure receiving member does not directly contribute to stopping water, it can be divided into two parts, which facilitates molding and mounting work.

[Brief description of drawings]

FIG. 1 is a sectional view of a submerged box gasket to which an embodiment of a submerged tunnel seal member according to the present invention is applied.

FIG. 2 is a cross-sectional view showing a compressed state of the submerged box gasket.

FIG. 3 is a view conceptually showing how the submerged box gasket is attached to the submerged box.

FIG. 4 is a graph showing a relationship between a deformation amount of a submerged box gasket and a reaction force.

FIG. 5 is a graph showing a relationship between an inverted V-shaped seal rubber and a deformation amount thereof and a reaction force.

FIG. 6 is a graph showing a relationship between an inverted U-shaped seal rubber and its deformation amount and reaction force.

FIG. 7 is a graph showing a relationship between an O-type seal rubber and its deformation amount and reaction force.

FIG. 8 is a cross-sectional view of a conventional gina type packing.

FIG. 9 is a graph showing the relationship between the amount of deformation and the reaction force of a zin-type packing formed only of rubber.

FIG. 10 is a graph showing the relationship between the amount of deformation and the reaction force of a zener type packing with a reinforcing iron plate.

[Explanation of symbols]

 1 ... Gasket for submerged box (sealing member for submerged tunnel) 2 ... Submerged box 10 ... Pressure receiving rubber (pressure receiving member) 11 ... Reinforcing iron plate (reinforcing plate)

Claims (4)

[Claims] 1. A submerged tunnel construction method, which is interposed between the joint end faces of each submerged box to maintain airtightness in the tunnel, is formed at a predetermined height by an elastic material, and is formed on the joint end face of the submerged box. A pressure receiving member that is arranged along the opening edge and receives the joining pressure of the submerged box on the other side of the joining, and is formed a predetermined amount higher than the pressure receiving member by an elastic material, and along the opening edge around the entire circumference of the opening portion. A seal member for continuously arranging the seal member, which is in pressure contact with the joint end surface of the submerged box on the joint partner side to maintain airtightness, and a seal member for a buried tunnel. 2. The pressure receiving member has a substantially rectangular cross-sectional shape, and the sealing member has a cross-sectional shape that covers the outer surface of the pressure receiving member with a predetermined gap, and The seal member for a submerged tunnel according to claim 1, wherein the seal member is arranged so as to cover the pressure receiving member on the joint end surface. 3. The seal member for a submerged tunnel according to claim 2, wherein the pressure receiving member has a reinforcing plate such as an iron plate inserted in a layer shape in a height direction thereof. 4. The buried tunnel sealing member according to claim 2, wherein the sealing member has a trapezoidal cross-sectional shape that widens toward the mounting surface side.