JPH09316848A - Underwater foundation mound protecting net structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the weight of an underwater foundation mound and to expand its protection range by reducing an area receiving wave impacts by attaching a foundation riprap movement preventing net to an outer frame formed by flatly assembling a steel frame. SOLUTION: The nets of a grating-like chain 4 are formed at specified intervals in a steel outer frame 2 and the movement of an underwater foundation mound caused by the wave impacts of foundation ripraps is prevented. Then, in order to protect the corner base part of an end part caisson, a part of which is continuously built on the underwater foundation mound 11, a net structure 1 is lifted by a crane and installed in the corner base part. Since the net structure 1 is formed in a flat shape, its area for receiving waves is smaller than that of a conventional foot protection block and its weight not moved by waves itself is greatly reduced, it is easily installed and eliminated and the protecting range of the underwater foundation mound is expanded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater foundation mound protection net structure for protecting an underwater foundation mound used for construction of a breakwater, a seawall, and an offshore structure of a harbor from waves.

[0002]

2. Description of the Related Art When constructing a breakwater or a seawall by a structure such as a caisson, an underwater foundation mound is provided by previously laying rubble stones on the installation foundation, and then a plurality of divided structures are sequentially constructed underwater foundation. Build breakwaters and revetments by continuously installing them on the mound.

When a structure such as a caisson is installed on the underwater foundation mound, it may not be possible to continuously install the structure after construction of the underwater foundation mound depending on the construction scale and weather conditions. In such a case, the stone of the underwater foundation mound may be blown off (washed out) by the impact of the wave before the next structure is installed. Especially, at the base of the end of the existing structure, waves tend to concentrate, and stones are blown (washed) to create holes in the underwater foundation mound, which stabilizes the structure such as caisson to be installed next. There are many cases where the property is impaired, and it takes a considerable amount of time to repair the hole.

As a method of preventing the stones of the underwater foundation mound from being blown off by the impact of such a wave, at the root of the end structure conventionally installed on the underwater foundation mound,
We have installed a concrete rooting block that weighs so that it will not be blown away by the impact of waves (it will not move), and it has been used as a weight to protect stones in the underwater foundation mound from being blown off.

[0005]

The protection of the underwater foundation mound by installing a concrete rooting block of a weight that is not blown off by the impact of the above waves is an obstacle when installing the structure such as the next caisson. It is necessary to remove the consolidation block on the underwater foundation mound at the base of the existing end structure.

However, the conventional concrete root blocks require a considerable amount of time for their installation and removal work. The reason is that the size of each root block is limited due to the suspension load of a crane ship used to install concrete root blocks, and the number of root blocks required to protect the underwater foundation mound is limited. The cause is that there are many.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, to suppress the movement of the rubble of the foundation of the underwater foundation mound, and to reduce the area to receive the impact of the wave to reduce the weight, thereby making the underwater foundation mound. It is to provide an underwater foundation mound protection net structure with an expanded protection range.

[0008]

The underwater foundation mound protection net structure of the present invention comprises a chain or a wire for preventing the movement of foundation rubble in an outer frame formed by planarly assembling a steel frame. The net formed by is attached. In this way, by installing a net for preventing the movement of foundation rubble in the steel outer frame, it is possible to prevent damage to the underwater foundation mound by capturing the rubble that is blown by the net, and the net structure is flat. Due to the steel outer frame and the net, the area that receives the waves is extremely small, and the weight required for not being moved by the waves can be greatly reduced. As a result, the required weight per piece can be reduced and the underwater foundation mound protection range can be widened as compared with the conventional concrete root consolidation block. As a result, the underwater foundation mound protection net structure of the present invention has improved workability in installation and removal, and can be installed and removed in a short time.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The shape of the planar steel outer frame of the underwater foundation mound protection net structure of the present invention is different in size and shape depending on the protection range of the underwater foundation mound and the geometrical constraint on installation. It is determined. For example, as shown in FIG. 5, when protecting the underwater foundation mound 52 at the root of the corner of the caisson 51, a square steel outer frame 53 is used as shown in FIG. It is possible to use three frames 53, and as shown in FIG.
A combination of a rectangular steel outer frame 54 and a square steel outer frame 53 may be used, or as shown in FIG. 5C, an L-shaped steel outer frame 55 may be used. Further, when the size of the steel outer frame becomes large, as shown in FIG. 6, the reinforcing frame 62 may be incorporated so as to further partition the steel outer frame 61 to reinforce the strength. Further, when protecting the underwater foundation mound at the base of the round caisson, it goes without saying that the steel outer frame has a curved shape along the curved portion of the round caisson.

As the material of the steel outer frame of the present invention, round steel, steel pipe, shaped steel or the like can be used, but in order to secure the necessary weight of the net structure determined by the wave conditions, the steel pipe interior Alternatively, concrete, sand, etc. may be filled inside the or section steel.

The mesh of the net to be mounted in the steel outer frame of the present invention is determined by the size of the rubble used in the underwater foundation mound to be protected, and the pitch can be set in a lattice pattern. It may be from only one direction, but at least it must have a shape and size that can prevent the movement of rubble.

The net may be connected to the steel outer frame or the reinforcing frame by any structure as long as it is not destroyed by the movement of the rubble of the foundation.
The structure is simple to connect the net to the mounting piece by a shackle. The connecting part of this net needs to be strong enough not to be destroyed by the movement of rubble. The net can be formed by a chain, a wire, or the like, but at least the strength is required so that the net will not be cut by the movement of the rubble.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of a net structure for protecting an underwater foundation mound according to the present invention will be described below with reference to FIGS.
It will be described based on. FIG. 1 is an overall plan view of a square underwater foundation mound protection net structure of the present invention, FIG. 2 is an enlarged explanatory view of an essential part showing an example of connection of a net formed by a chain to a steel outer frame, and FIG. 3 is an actual view. A plan view showing a state in which six square underwater foundation mound protective net structures of the present invention are installed at the root of the existing caisson on the underwater foundation mound,
FIG. 4 is a sectional view of FIG.

1 and 2, 1 is a net structure for protecting a square underwater foundation mound, 2 is a steel outer frame in which round steel is welded or bolted into a flat square,
3 is an attachment piece welded and fixed to the inner surface of the steel outer frame 2 at a predetermined interval, 4 is a chain attached in a grid pattern at a predetermined pitch to form a net in the steel outer frame 2, and 5 is a chain 4
With shackles that connect both ends to the mounting piece 3, the nets of the chains 4 are formed in a lattice pattern within the steel outer frame 2 at predetermined intervals, and if the net structure 1 is installed on the underwater foundation mound, The structure of the mound is designed to prevent movement due to the impact of the waves of rubble.

The mesh spacing of the chains 4 forming the net of the net structure 1 is determined by the size of the foundation rubble forming the underwater foundation mound, and the foundation rubble does not move out through the mesh of the chain 4. Further, the both ends of the chain 4 were connected to the steel outer frame 2 by the mounting piece 3 and the shackle 5, but if the strength is such that the connection part is not destroyed by the movement of the rubble of the foundation due to the impact of the waves, it will be It is also possible to use the coupling method of. Further, the net structure 1 is configured to have a weight that does not move by the impact of the waves.

With the above construction, the net structure 1 is composed of the net-like net formed of the steel outer frame 2 and the chain 4 and has a planar shape, so that it receives waves. The area is much smaller than that of the conventional consolidation block, and the weight for keeping itself from the waves can be greatly reduced. Therefore, the net structure 1 can reduce the required weight per piece as compared with the conventional rooting block, can be easily installed and removed, and can widen the protection range of the underwater foundation mound. .

As shown in FIGS. 3 to 4, the net structure 1 of the present invention includes an end caisson 12 which is partially continuously constructed on an underwater foundation mound 11 made of foundation rubble piled on the seabed. In order to protect the two corner roots, a crane ship (not shown) is moved to the vicinity of the end caisson 12, and the net structure 1 is hung by the crane to make the two corner roots of the end caisson 12 fit. Three pieces are installed and installed as shown in FIGS. 3 to 4.

By installing and arranging in this way,
At the two corner roots of the existing end caisson 12 where waves are likely to be concentrated, the underwater foundation mounds 11 are covered with three net structures 1, respectively. Therefore, the movement of the rubble of the foundation stone of the underwater foundation mound 11 due to the impact of the waves is prevented by the chain 4 of the lattice mesh forming the net of the net structure 1, and a hole is formed in the foundation of the underwater foundation stone 11 due to the movement of the foundation rubble stone. It will not be done.

When a new caisson is installed continuously to the existing end caissons 12, a crane ship (not shown) is moved to the vicinity of the end caissons 12 and the end caissons 1 are moved.
If the three net structures 1 installed and installed at the two corner roots of 2 are lifted and removed, the underwater foundation mound 11 can be connected to the end caisson 12 without repairing the caisson immediately. Can be installed.

[0020]

Since the underwater foundation mound protection net structure of the present invention has a planar shape composed of a steel outer frame and a net, the area for receiving waves is compared with the conventional rooting block. It is extremely small and can significantly reduce the weight because it is not moved by the waves.
Therefore, the net structure can reduce the required weight per piece as compared with the conventional rooting block, can be easily installed and removed, and can widen the protection range of the underwater foundation mound. .

[Brief description of drawings]

FIG. 1 is an overall plan view of a square underwater foundation mound protection net structure of the present invention.

FIG. 2 is an enlarged explanatory view of a main part showing an example of connection of a net formed of a chain to a steel outer frame.

FIG. 3 is a plan view showing a state in which six square underwater foundation mound protective net structures of the present invention are actually installed at an existing caisson root portion on the underwater foundation mound.

4 is a cross-sectional view of FIG.

FIG. 5 shows an installation example of the net structure of the present invention, where (a) is a case where three square net structures are used, and (b) is a square net structure and a rectangular net structure. When the objects are combined, (c) figure shows the case of the L-shaped net structure.

FIG. 6 shows an example of installation of a reinforcing frame on a steel outer frame, where (a) is a rectangular steel outer frame and (b) is L.
A case of a steel outer frame of a mold is shown.

[Explanation of symbols]

 1 Net structure 2, 53, 54, 55, 61 Steel outer frame 3 Mounting piece 4 Chain 5 Shackle 11, 52 Underwater foundation mound 12 End caisson 51 Caisson 62 Reinforcing frame

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Imai 4-53-3 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture Sumitomo Metal Industries, Ltd. (72) Takuya Kitamura 4-chome, Kitahama, Chuo-ku, Osaka City, Osaka Prefecture No. 33 In Sumitomo Metal Industries Co., Ltd. (72) Inventor Naoki Hayashi 2254 Ao, Aza, Kashima City, Ibaraki Prefecture In the Kashima Port Construction Office, 2nd Port Construction Bureau, Ministry of Transportation (72) Yoshikazu Moriya 2254, Ao, Kashima City, Ibaraki Prefecture Address 2nd Port Construction Bureau, Ministry of Transport Kashima Port Construction Office (72) Inventor Hayato Aoyama 2254 Ao, Ooshima, Kashima-shi, Ibaraki Prefecture 2nd Port Construction Bureau Kashima Port Construction Office (72) Inventor Masaru Watanabe Kashima, Ibaraki Prefecture 2254 Ao, Ao, Shiga City, Kashima Port Construction Office, Second Port Construction Bureau, Ministry of Transport (72) Inventor, Masaaki Kitabata 2254, Ao, Ao, Kashima City, Ibaraki Prefecture Ministry of the Second Port Construction Bureau Kashima Port Construction Office (72) Inventor Kazuyuki Soma 2254 Ao, Ao, Kashima City, Ibaraki Prefecture Ministry of Transport Second Harbor Construction Bureau Kashima Port Construction Office (72) Inventor Jun Fukukawa Kashima City, Ibaraki Prefecture 2254 Ao, Ao, Kashima Port Construction Office, Second Port Construction Bureau, Ministry of Transport (72) Inventor, Kazuyuki Yanagisawa 1-3-8 Nihonbashi-Bakurocho, Chuo-ku, Tokyo

Claims (1)

[Claims] 1. In a protective structure for an underwater foundation mound formed by laying stones on the seabed, a net for preventing foundation rubble movement is provided in an outer frame formed by planarly assembling a steel frame. Underwater foundation mound protection net structure characterized by being installed.