JPH11336108A - Rubber gasket for sunk case - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber gasket for a sunk case capable of reducing and dispersing stress during compression, allowing designing of a rubber gasket of a low reaction type and improving durability and water stopping performance. SOLUTION: A rubber gasket mainbody 10 in an almost sectionally trapezoidal shape has a void portion 12 formed at the almost sectional center to communicate with a sea water inflow side face 10a, on which the water pressure P of sea water W operates, via a slit 11, the void portion 12 being continuously formed in the longitudinal direction of the rubber gasket mainbody 10 or at a preset space thereto. The sea water W flowing in the void portion 12 via the slit 11 is sealed in the void portion 12 by the crush of the slit 11 so that the primary water stopping effect of sunk case elements 1a, 1b can be produced by the reaction of the rubber gasket mainbody 10 due to resilience and the compressive reaction of the sea water W sealed in the void portion 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber gasket for submerged boxes, and more particularly to an improvement in a rubber gasket attached to an end face of a submerged box element used when constructing an underwater tunnel.

[0002]

2. Description of the Related Art Conventionally, a submerged box constructed when a port submarine tunnel or the like is constructed is, for example, as shown in FIG. A submerged box element 1b in which a band-shaped rubber gasket 2 having a substantially trapezoidal cross section as shown is attached to the peripheral edge of the end face is submerged, and a submerged box element 1b is provided by a pulling jack 3 attached to the existing submerged box element 1a. Attraction.

[0003] At this time, the rubber gasket 2 comes into contact with the end face of the existing submerged box element 1a and is slightly compressed to produce a primary water stopping effect. Next, when the water in the space 4 defined by the end faces of the two submerged box elements 1a and 1b and the rubber gasket 2 is drained from the existing submerged box element 1a side, the water pressure difference acting on the opposite end face causes the water pressure difference. At the same time that the next water stopping effect is obtained, the newly installed submerged box element 1b is further replaced with the existing submerged box element 1a.
The rubber gasket 2 is pressed to the side to increase the amount of compression, so that a highly safe water stopping effect can be obtained.

[0004] After draining, the two submerged box elements 1
By removing the bulkheads a and 1b, the submerged box elements 1a and 1b penetrate.

[0005]

As shown in FIG. 5, the conventional rubber gasket 2 has a nose 5a.
Generally, the main body portion 5b and the flange portion 5c are formed in a substantially trapezoidal cross section, and have a solid cross section having a large reaction force in consideration of long-term withstand pressure and water stoppage. However, in the rubber gasket 2 as described above, as shown in FIG. 6, stress concentration occurs at the cross-sectional center portion 2X of the rubber gasket 2 during compression due to structural and shape reasons.

[0006] In the submerging method by rigid connection,
After joining the submerged box elements 1a and 1b, the concrete is poured into the submerged box elements 1a and 1b.
If the compression reaction force of the rubber gasket 2 is small at the time of joining, it is possible to expect the downsizing of various components of the submerged box, for example, the drawing jack 3, etc., and to reduce the compression reaction force of the rubber gasket 2. It had been.

As shown in FIGS. 7 and 8, the conventional rubber gasket 2 has a stopper 6 and the like attached to the submerged box element 1a in order to prevent a lateral fall or deformation due to external water pressure P during an earthquake. Was.

Further, a conventional rubber gasket has been proposed in which a watertight portion is provided with a closed cavity in order to avoid excessive stress concentration at the time of large deformation. However, since they are manufactured integrally, the size and the position of the hollow portion change, and the performance may vary. Also, if the overall height of the rubber gasket is increased, a large load is required to compress the main body, there is a problem that it can not cope with large deformation with low reaction force, and the compression set becomes large, so long-term water stoppage There was a problem of being inferior.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the stress at the time of compression and to disperse, and at the same time, it is possible to design a rubber gasket of a low reaction force type, and it is possible to improve the durability and the water stoppage of a submerged box. To provide a rubber gasket.

[0010]

According to the present invention, in order to achieve the above object, a rubber gasket body having a substantially trapezoidal cross section has a hollow portion at the center of the cross section which can communicate with a side surface on the seawater inflow side. The gist is that. The present invention is configured as described above, and by forming a cavity that can communicate with the seawater inflow side surface at the center of the cross section of the rubber gasket main body, it is possible to reduce and disperse stress during compression, The design of the low reaction force type can be easily performed, and the improvement of the water stoppage utilizing the external pressure is possible.
Durability can also be improved.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The same components as those of the conventional example are denoted by the same reference numerals, and description thereof will be omitted. FIG. 1 (a),
(B) is a cross-sectional view of the band-shaped rubber gasket main body 10 according to the first embodiment of the present invention when it is not compressed and when it is compressed, and 1a and 1b show submerged box elements.

The rubber gasket body 10 having a substantially trapezoidal cross section has a hollow portion 12 which can communicate with a seawater inflow side surface 10a to which the water pressure P of the seawater W acts through a slit 11 at a substantially central portion of the cross section. This cavity 12 is
The rubber gasket body 10 is formed continuously or at a predetermined interval in the longitudinal direction. With this configuration, the rubber gasket main body 10 is brought into the state shown in FIG. 1B by pulling the buried element 1b side from the state shown in FIG. 1A to the buried element 1a side by a drawing jack (not shown). The top portion 10b contacts the end face of the existing submerged box element 1a, and is gradually compressed, and the slit 11 formed on the seawater inflow side surface 10a is pressed. That is, the top 10b of the rubber gasket main body 10 is compressed by the moving amount δ of the submerged box element 1b, and the slit 11 is pressed by the amount of compression.

Then, the hollow portion 12 is formed through the slit 11.
The seawater W flowing into the inside is sealed in the hollow portion 12 by the slit 11 being crushed, and the reaction force due to the elastic force of the rubber gasket body 10 and the hollow portion 1
The primary reaction of the submerged box elements 1a and 1b is caused by the compression reaction force of the seawater W sealed in the inside 2.

2 (a), 2 (b) and 2 (c) show a second embodiment of the present invention in which the belt-shaped rubber gasket main body 10 is not compressed, when water pressure is applied, and when compressed. FIG. 3 is a cross-sectional view of the rubber gasket main body 20 according to the second embodiment.
The hollow portion 2 is located substantially at the center of the cross section of the rubber gasket main body 20.
1, a lid-shaped nose 22 for opening and closing the hollow portion 21 is integrally formed near the top 20a of the rubber gasket main body 20.

With such a configuration, when the rubber gasket main body 20 is not compressed, the lid-shaped nose 22 opens the opening 21a of the hollow portion 21 and rises by the water pressure P.

From this state, the submerged box element 1a is pulled by the drawing jack (not shown) on the submerged box element 1b side.
2 (b), the nose 22 of the rubber gasket main body 20 is compressed from above to narrow the opening 21a of the cavity 21, and further, as shown in FIG. 2 (c). When the element 1b is pulled, the nose 22 of the rubber gasket main body 20 is
At the same time as being pressed against the top 20a of the zero, the opening 21a of the cavity 21 is completely closed, and the seawater W flowing into the cavity 21 is sealed inside the cavity 21.

Thus, similarly to the first embodiment, the submerged box elements 1a, 1b are formed by the reaction force of the rubber gasket body 20 by the elastic force and the compression reaction force of the seawater W sealed in the cavity 20. The primary water stopping effect is produced. FIGS. 3A and 3B are cross-sectional views of the rubber gasket main body 30 according to a third embodiment of the present invention, in a non-compressed state and when a water pressure is applied.
The one side surface 30a is formed to be inclined toward the seawater inflow side at an inclination corresponding to the water pressure P at the water depth, and the other side surface 30b is formed vertically.

A hollow portion 31 is provided substantially at the center of the cross section of the rubber gasket main body 30, and a slit 32 communicating with the hollow portion 31 is provided with a vertical side surface 3 on which the water pressure acts.
0b. Therefore, the rubber gasket body 30
In the non-compressed state, the slit 32 communicating with the cavity 31 is opened toward the seawater inflow side as shown in FIG. 3A, and the seawater W flows into the cavity 31. When the water pressure P acts on the vertical side surface 30b due to an earthquake or the like, the rubber gasket main body 30 falls down as shown in FIG. Accordingly, the overall height becomes higher, resulting in a uniform symmetrical cross-sectional shape.

Accordingly, when the buried box element 1b undergoes compression deformation, the displacement δ of the buried box element 1b
Only the top of the rubber gasket main body 30 is compressed, and the slit 32 is compressed by the compression amount, and the seawater W flowing into the cavity 31 is sealed in the cavity 31 by the collapse of the slit 32. In this state, the primary water stopping effect of the submerged box elements 1a and 1b is generated by the reaction force due to the elastic force of the rubber gasket main body 30 and the compression reaction force of the seawater W sealed in the cavity 31.

In addition, in the rubber gasket main bodies 10, 20, 30 in the first to third embodiments, the hollow portions 12, 21, 31 are formed, and at the same time, FIGS.
It is also possible to form a low reaction force type rubber gasket by forming a closed cavity 40 as shown by the one-dot chain line in (b) to FIGS. 3 (a) and 3 (b).

[0021]

According to the present invention, the rubber gasket main body formed in a substantially trapezoidal cross section as described above has a hollow portion which can communicate with the seawater inflow side surface at a substantially central portion of the cross section. It has excellent effects. . Stress reduction and dispersion during compression can be performed. . A low reaction force type rubber gasket can be designed. . It is possible to improve the water stoppage utilizing external pressure. . It is possible to provide the elastic shape of the rubber gasket main body with the function of preventing the side from falling down due to the external pressure. . The durability and the water stopping property can be improved.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are cross-sectional views of a band-shaped rubber gasket main body according to a first embodiment of the present invention when not compressed and when compressed.

FIGS. 2 (a), (b) and (c) show a second embodiment of the present invention in which a belt-shaped rubber gasket main body is not compressed;
It is sectional drawing at the time of a water pressure acting, and at the time of compression.

FIGS. 3 (a) and (b) show a third example of a rubber gasket main body.
It is sectional drawing at the time of the non-compression which shows embodiment, and when a water pressure acts.

FIG. 4 is an explanatory view showing a configuration of a joining portion of a conventional buried box.

FIG. 5 is a sectional view of a conventional rubber gasket.

FIG. 6 is an explanatory diagram showing a stress generation state when a conventional rubber gasket is compressed.

FIG. 7 is a cross-sectional view showing the phenomenon of a conventional rubber gasket falling down.

FIG. 8 is a cross-sectional view of a conventional rubber gasket provided with a stopper for preventing a lateral fall.

[Explanation of symbols]

1a, 1b Buried Box Element 2 Rubber Gasket 3 Pulling Jack 2X Center of Section 5a Water Stop 5b Main Body 5c Flange 6 Stopper 10 Rubber Gasket Main Body 10a Seawater Inflow Side Side 10b Top 11 Slit 12 Cavity W Seawater

Claims (5)

[Claims] 1. A band-shaped rubber gasket for a submerged box having a substantially trapezoidal cross section attached to an end surface of a submerged box element, wherein the rubber gasket main body formed into a substantially trapezoidal cross section includes:
A rubber gasket for buried boxes, which has a hollow part that can communicate with the seawater inflow side surface at the approximate center of the cross section. 2. The rubber gasket for submerged box according to claim 1, wherein the cavity is formed continuously or at a predetermined interval in a longitudinal direction of the rubber gasket main body. 3. Near the top of the rubber gasket body,
3. The rubber gasket for a submerged box according to claim 1, wherein a nose for opening and closing the cavity is provided. 4. The rubber gasket for a submerged box according to claim 1, wherein the rubber gasket main body is formed so as to be inclined toward the seawater inflow side at an inclination corresponding to the water pressure at the depth of water. 5. The rubber gasket body has a closed cavity formed inside the main body of the rubber gasket.
Rubber gasket for submerged box as described in.