JP2988514B2 - Rubber plate for concrete caisson - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction device mounted on a bottom surface of a concrete caisson for preventing a concrete caisson used for construction of a breakwater, a quay, a reclamation seawall, etc. of a harbor or the like due to a wave force or an earthquake. The present invention relates to a rubber plate as a member.

[0002]

2. Description of the Related Art Conventionally, a concrete caisson has been used to construct a breakwater, a quay, a reclaimed revetment, etc. The concrete caisson is completed by excavating the sea floor and submerging it on a foundation mound piled with crushed stone. At this time, in order to prevent the installed concrete caisson from sliding, an asphalt mat is laid on the foundation mound or a rubber plate is attached to the bottom of the concrete caisson. Such concrete caisson with a rubber plate attached thereto is disclosed in, for example, Japanese Utility Model Publication No. 4-37969, Japanese Utility Model Publication No. 4-55097, and Japanese Patent Publication No. 5-1.
No. 9617, and the like.

A method of attaching a rubber plate to a part of the bottom of a concrete caisson (Japanese Utility Model Publication No. 4-37969).
No.) and a method of attaching it to the entire bottom surface
No. 97 and Japanese Patent Publication No. 5-19617). However, all of these rubber plates are formed with a constant hardness in the thickness direction. Since the rubber plate is used to prevent the sliding of the concrete caisson, it is preferable that the friction coefficient is large, but the hardness of the rubber is not particularly considered in relation to the friction coefficient. On the other hand, in order to increase the coefficient of friction, a circular groove is continuously provided on the lower surface (contact surface with the base mound) of a rubber plate as a friction member (Japanese Utility Model Publication No. 59-31773), (Japanese Patent Publication No. 5-19617).

[0004]

However, any of the above-mentioned known methods are intended to increase the resistance by making digging stones penetrate into holes or grooves. It is preferable that the hardness of the rubber plate is harder to make the crushed stone penetrate, but the higher the hardness, the lower the friction coefficient. Conversely, if the hardness is low, the coefficient of friction increases, but it is not possible to securely fix the foundation bolts and mounting brackets for attaching the rubber plate to the concrete caisson, and when installing on the foundation mound, when sliding, The concrete caisson and rubber plate cannot be firmly fixed and placed because the rubber plate is cut by the foundation bolt. Further, in order for the shards to bite, it is necessary to match the unevenness of the mound to a certain extent, and for that purpose, the size of the holes and grooves must be naturally increased. The present invention has been made in view of the current situation, and provides a rubber plate for a concrete caisson that can be firmly fixed to a concrete caisson and can increase the friction coefficient.

[0005]

The present invention has the following configuration to achieve the above object. In other words, the concrete caisson rubber plate according to claim 1 has an overall thickness of 3
The upper rubber layer is composed of two upper and lower rubber layers having different hardnesses of 0 mm to 50 mm.
A groove is provided on the lower surface of the lower rubber layer higher than the ISA hardness, and a depth dimension of the groove is 5 mm to 20 mm, and when reaching the upper rubber layer, a depth dimension until reaching the upper rubber layer, The width dimension is 5 mm to 40 mm, the interval dimension between the grooves or the interval dimension between the groove and the side of the rubber plate is 20 mm to 4 mm.
90 mm and the ratio of the groove area to the whole is 5 to 30%. In the rubber plate for a concrete caisson according to claim 2, the thickness of the lower rubber layer is 1 to 3 times the thickness of the upper rubber layer, the upper rubber layer has a JISA hardness of Hs 70 to 80, and the lower rubber layer has a HISA of 70 to 80. JIS
A hardness is Hs 55-68. The rubber plate for a concrete caisson according to claim 3 is
The rubber plate has a planar rectangular shape, and the grooves are provided in a lattice shape. The rubber plate for a concrete caisson according to claim 4 is characterized in that a side surface of the rubber plate is pressed toward a lower surface.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a bottom view of a rubber plate according to the present invention, and FIG.
The rubber plate 1 is a square having a side of about 1 m in a plane, and has a two-layer structure including an upper rubber layer 2 abutting on a bottom surface of a concrete caisson and a lower rubber layer 3 placed on a foundation mound. The side surfaces of the rubber layer 2 are formed substantially vertically, while the side surfaces of the lower rubber layer 3 are inclined inward and narrow. The rubber plate 1 has a two-layer structure because the upper rubber layer 2 firmly adheres to the concrete caisson and the lower rubber layer 3 increases the friction coefficient as a friction member. The thickness of the entire rubber plate 1 is 30 to 5
0 mm, and the ratio of the thickness of the upper rubber layer 2 to the thickness of the lower rubber layer 3 is such that the thickness of the lower rubber layer 3 is 1
Up to three times. In order to securely attach the rubber plate 1 to the bottom surface of the concrete caisson and to prevent the rubber plate from cracking due to mounting brackets after being set on the foundation mound, the upper rubber layer 2 having a high JISA hardness is 10 mm. This is because the above thickness is required.

The upper rubber layer 2 has a JISA hardness higher than that of the lower rubber layer 3. The upper rubber layer has a JISA hardness of Hs 70 to 80 and the lower rubber layer has a JISA hardness of Hs 5.
5 to 68. The JISA hardness of the upper rubber layer 2 is Hs7
If it is less than 0, it is too soft to function as a fixing portion to the concrete caisson. On the other hand, if the lower rubber layer 3 has a JISA hardness of 68 or more, it is not sufficiently deformed so as to wrap the crushed stone of the base mound, and the stain with the crushed stone is poor. Also, the lower rubber layer 3
If the JISA hardness is less than Hs55, it is too soft to function as a friction member.

Further, as shown in FIG. 1, the lower surface of the lower rubber layer (the surface mounted on the base mound)
And vertical grooves 7 are provided vertically and horizontally in a grid pattern. If the JISA hardness is lowered, the frictional resistance increases but the tear strength decreases. Therefore, by providing the lateral grooves 6 and the vertical grooves 7, even if the JISA hardness is high to some extent, sufficient tear strength and frictional resistance can be obtained. It is a balance. Therefore, this groove allows a shard to enter,
It is provided not for engaging with the unevenness of the split stone but for making the stain of the lower rubber layer 3 with the split stone more favorable. Therefore, the sizes of the grooves 6, 7 are formed as follows. That is, the depth of the groove is set to 5 mm to 20 mm. However, when the groove reaches the upper rubber layer, the dimension is set to reach the upper rubber layer, and no groove is provided in the upper rubber layer 2. This is because the strength of the upper rubber layer is not reduced. On the other hand, the width of the groove is 5 mm to 40 mm. The depth dimension and width dimension of the groove are determined by the thickness and hardness of the lower rubber layer 3, the size of the concrete caisson, the size of the slab of the foundation mound, and the like.

The distance l between the grooves 6 and 7 is 20 m.
m to 490 mm. However, in the case of providing a minimum number of crosses as shown in FIG. 3, the distance l between the groove and the side surface parallel to the groove is set to 490 mm or less. Therefore, when one side of the rubber plate 1 is 1000 mm or more, two or more grooves are provided,
When one groove is used, one side has a size of 1000 mm or less. Further, the ratio of the groove area in the entire rubber plate is 5 to 30%. If the ratio of the groove area is 5% or less, the function of the groove cannot be achieved, and if it is 30% or more, the protruding surface is too small to enclose the fracturing stone and the friction coefficient cannot be increased. The direction of the groove is typically provided in parallel to the side surface of the rubber plate as shown in FIG. 1, but it may be provided in an oblique direction as shown in FIG. And the like can be arbitrarily provided. In this embodiment, since the side surface of the lower rubber layer 3 is narrowed inward toward the lower surface, when the rubber plates 1 are arranged in contact with each other, a groove is formed between adjacent rubber plates.

Next, the method of attaching the rubber plate 1 to the concrete caisson is not particularly limited, and can be performed by any means. 1 to 3 show a rubber plate 1.
An example of the mounting method is shown. A bolt insertion hole 9 for inserting an anchor bolt 8 is formed in an appropriate place of the rubber plate 1 and placed. The rubber plate 1 is attached by embedding a portion protruding from the rubber layer 2 in a concrete caisson. FIG. 5 shows another mounting method, in which an anchor bolt 13 is fixed to a reinforcing member 11 made of an iron plate embedded in the upper rubber layer 2 via a mounting member 12. The rubber plate 1 is attached by embedding a portion protruding from the rubber layer 2 in a concrete caisson. The rubber plate 1 may be attached to the entire bottom surface of the concrete caisson, or may be attached to only one side.

[0011]

EXAMPLES Examples of the present invention are shown together with comparative examples. The rubber plate in the example is a square having a side of 1000 mm, the upper rubber layer has a JISA hardness of Hs70 and a thickness of 15 mm, and the lower rubber layer has a JISA hardness of Hs55.
The thickness is set to 25 mm, and grooves having a depth of 10 mm and a width of 5 mm are provided on the lower surface in a grid pattern at intervals of 75 mm. On the other hand, the rubber plate of Comparative Example 1 has a thickness of 40 mm and has a JISA hardness of Hs70 and has a single-layer structure with a smooth lower surface. The rubber plate of Comparative Example 2 has a thickness of 40 mm and a JISA hardness of Hs70. Hs6
0, and the lower surface is formed smoothly. These rubber plates were attached to the bottom of a concrete vehicle and the friction coefficient was measured. As shown in FIG. 6, the concrete driving body 15 was manufactured to be a flat square having a length L of one side of 1000 mm and a height H of 530 mm, like the rubber plate. Each of the rubber plates was attached to the bottom surface of the concrete driving body 15 and placed on a shard 16, immersed in water 17, and the coefficient of friction based on the ratio of the horizontal resultant force P to the vertical resultant force W was measured.

When the vertical resultant force W was set to 20 t, 40 t, and 60 t, measurement was performed a plurality of times. The measurement results are as shown in Table 1. In each of the examples, the coefficient of friction was improved as compared with the comparative example.

[0013]

[Table 1]

[0014]

As described above, the present invention has the following advantages. That is, the upper rubber layer can be securely attached to the concrete caisson, while the lower rubber layer increases the coefficient of friction,
Sliding can be prevented. The lower rubber layer is softer than the upper rubber layer, and by providing a groove, the lower part of the concrete caisson enters between the split stones by its own weight, and at the same time, is deformed so as to enclose the split stone, so the resistance is further increased. . Further, when the same friction coefficient as in the related art is sufficient, the thickness of the entire rubber plate can be reduced, and a rubber plate that is less expensive can be provided. Further, since the rubber plate is pressed down toward the lower surface, a groove is also formed between the rubber plate and an adjacent rubber plate, and the stain on the shard is improved.

[Brief description of the drawings]

FIG. 1 is a bottom view of a rubber plate according to the present invention.

FIG. 2 is a partially enlarged sectional view of the same.

FIG. 3 is a bottom view of a rubber plate showing another forming method in which grooves are provided in a cross shape.

FIG. 4 is a bottom view of a rubber plate showing another forming method in which grooves are provided in an oblique direction.

FIG. 5 is a partially enlarged sectional view showing an example of attachment of a rubber plate to a concrete caisson.

FIG. 6 is an explanatory sectional view showing a method of measuring a friction coefficient.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rubber plate 2 Upper rubber layer 3 Lower rubber layer 6 Groove 7 Groove 8 Anchor bolt 9 Bolt insertion hole 11 Reinforcement member 12 Mounting member 13 Anchor bolt 15 Concrete body 16 Split stone 17 Water

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Hiroetsu Izuma, 1 Nobesawa, Kaisei-cho, Ashigara-gun, Kanagawa Prefecture Inside Meiji Rubber Chemicals Kanagawa Plant (56) References JP-B 5-19617 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02B 3/06-3/12 E02D 23/02

Claims (4)

(57) [Claims] 1. The upper rubber layer is composed of two upper and lower rubber layers having different hardnesses with a total thickness of 30 mm to 50 mm, and the upper rubber layer has a higher JISA hardness than the lower rubber layer. A groove is provided, and the depth of the groove is 5 mm to 20 mm. When the groove reaches the upper rubber layer, the groove has a depth to reach the upper rubber layer, and the width is 5 m.
m to 40 mm, the distance between the grooves or the distance between the grooves and the side of the rubber plate is 20 to 490 mm, and the ratio of the groove area to the whole is 5 to 30%. Rubber plate. 2. The thickness of the lower rubber layer is 1 to 3 times the thickness of the upper rubber layer, and the upper rubber layer has a JISA hardness of Hs7.
0-80, JISA hardness of lower rubber layer is Hs 55-68
The rubber plate for a concrete caisson according to claim 1, wherein: 3. The rubber plate for a concrete caisson according to claim 1, wherein the rubber plate has a planar rectangular shape, and the grooves are provided in a lattice shape. 4. The rubber plate according to claim 1, wherein a side surface of the rubber plate is narrowed toward a lower surface.
A rubber plate for a concrete caisson according to the above item.