JPH0649824A - Breakwater - Google Patents

Abstract

PURPOSE:To show the sufficient water breaking efficiency in spite of light weight and simple structure thereof, and cope with a large water depth easily. CONSTITUTION:A precast plate 4 made of reinforced concrete is attached to each joint 5 stood on a rubble-mound 1 to form arch-like trusses 2 continuously. An inhibit pile 3 is placed between each truss 2 to support both ends of the truss 2 with these inhibit piles 3, and each space forming a triangle of the truss 2 is filled with the filling material at need.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breakwater and a breakwater.

[0002]

2. Description of the Related Art Conventionally, as a breakwater, a plurality of caissons are continuously installed on a rubble mound created by throwing rubble stones into the seabed, and each caisson is filled with a filling material such as sand or soil to stabilize it. Rigid body stable type, or a pile structure type in which a large number of steel pipe piles are struck on the seabed and a frame is assembled to the pile to form a transmissive structure is generally used. Among them, the rigid body type does not need to consider the connection between the caissons, so it has the advantage that it can be easily constructed and the construction period is short, while the pile structure type has a prefabricated type. Since it can be assembled locally, there is an advantage that large heavy objects such as caisson need not be transported to the construction position.

[0003]

By the way, recently, as the ocean development progresses, breakwaters are often constructed in the deep water region, and the following problems have occurred. In other words, in the above rigid body type, the caisson must be larger and larger, so that not only is its production, transportation or installation troublesome, but also the rubble mound as a foundation must be constructed with high rigidity. On the other hand, in the pile structure type, a large number of large piles must be driven, and the number of frames to be assembled to this pile also increases, so that in all types, a decrease in construction efficiency and an increase in cost are avoided. I couldn't do it.

The present invention has been made in view of the above-mentioned conventional problems, and provides a breakwater which exhibits a large wave-breaking effect despite its small size, light weight, and simple structure, and thus can easily cope with deep water. The purpose is to do.

[0005]

In order to achieve the above object, the present invention is constructed such that a truss formed by connecting precast plates made of reinforced concrete to each other through a joint is installed on a rubble mound by on-site assembly. It is characterized by having done.

In the present invention, the truss may have a transparent structure or a closed structure, but in the case of the closed structure, it is desirable to fill the inside space surrounded by the precast plate with the filling material. In addition, the present invention, the truss,
It is also possible that the convex surface of the arch is in the shape of an arch that faces the incoming wave direction, and both ends of the truss are supported by restraining piles that are erected on the rubble mound.

[0007]

In the breakwater constructed as described above, the truss structure increases the strength relative to the weight, and even if the breakwater is small and lightweight, it exerts a sufficient breakwater effect. Further, the truss has a simple structure in which precast plates are connected through a joint, and in combination with the reduction in size and weight, it can be easily constructed by on-site assembly. Furthermore, when the interior is filled with a filling material or an arch-shaped truss is used, the strength is further improved, and thus the wave-preventing effect is further enhanced.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIGS. 1 to 5, reference numeral 1 denotes a rubble mound formed on the seabed, and a plurality of arch-shaped trusses 2 and a restraining pile 3 for commonly supporting both ends of each truss 2 are installed on the rubble mound 1. Has been done. The truss 2 is formed by connecting the precast plates 4 made of reinforced concrete as truss structural members to each other through joints 5 described later, and is installed so that the arch convex surface faces the incoming wave direction A. Has been done. Then, each chamber 6 in the truss 2 partitioned and formed by the three precast plates 4 has a watertight structure by the joint 5 and the concrete bottom plate 7 cast in place on the inner bottom part thereof. Filling material 8 such as sand and soil is filled (FIG. 4). In addition, truss 2
Has its height set to project from the sea level,
The upper end opening protruding from the sea surface is covered with a reinforced concrete lid 9 (FIG. 4).

On the other hand, the restraint pile 3 is, as shown in FIG. 5 well, a pile body (in this case, a steel pipe pile) 10 that is placed in the rubble mound 1, and the pile body 10 is previously placed around the pile body 10. And a plurality of concrete pile head walls 11 and one end of which is embedded in the pile head wall 11 and the other end of which is attached to a locking tool (not shown) projecting from the joint 5 that constitutes the truss 2. Connection chain 12
And a concrete support wall 13 cast in place between the pile head wall 11 and each truss 2. That is, both ends of each truss 2 are abutted against the restraint pile 3, and the chain 12 restricts the separation from the restraint pile 3, thereby preventing lateral movement and tilting of the truss 2.

Here, as shown in FIG. 6, the joints 5 for connecting the precast plates 4 are provided with a plurality of U-shaped mounting brackets 15 protruding from the end face of each precast plate 4 in a row and each mounting bracket. A spiral rebar 16 extending through 15 and connecting a plurality of precast plates 4 through the mounting bracket, and this spiral rebar
A guide post 17 which will be described later and is used as a guide for the 16 and a concrete column which is cast around the guide post 17 so as to wrap around the end of the precast plate 4 including the mounting bracket 15 and the spiral rebar 16. It consists of 18.

The guide post 17 has a vertical groove 17a into which the fitting 15 can be fitted and a spiral groove 17b into which the spiral rebar 16 can be fitted.
And a disk-shaped template plate 19 on which pins 20 for positioning the precast plate 4 are set up is integrally provided at the lower end thereof. When constructing the truss 2, first, the guide post 17 is erected on the rubble mound 1 using, for example, a support arm (not shown) extended from the work boat, and then attached to the vertical groove 17a of the guide post 17. Metal fittings 15
And the precast plate 4 is placed on the template 19. Then, under this condition, the spiral groove of the guide post 17
When the spiral rebar 16 is rotated with 17b as a guide, the spiral rebar 16 advances from the upper side to the lower side while sequentially inserting the mounting brackets 15,
The plurality of precast plates 4 are connected via the mounting fittings. Therefore, after that, by assembling the formwork (not shown) with the contour along the circumference of the form plate 19, and placing the underwater concrete in the formwork to form the concrete columns 18,
A joint 5 as a rigid structure is obtained, and each precast plate 4
Are rigidly and watertightly connected via this joint 5 to complete one block having an independent chamber 6.

In this way, blocks having independent chambers 6 are completed one after another, and in parallel with this, underwater concrete is placed at the bottom of the chambers 6 sequentially from the first block to form the bottom plate 7. To do. Then, after the bottom plate 7 is solidified, the filling material 8 is put into the chamber 6, the seawater in the chamber 6 is replaced with the filling material 8, and the lid body 9 is covered. Complete truss 2. After that, another truss 2 is completed so as to be connected to this, and at this stage, the pile main body 10 which constitutes the restraining pile 3 is driven in the middle of the connecting portion at both ends of the two trusses 2. A pile head wall 11 is provided around the pile main body 10 in advance. After the pile main body 10 is driven, the connecting chain 12 held by the pile head wall 11 is projected on the joint 5 of the truss 2. It is attached to a locking tool (not shown). Next, the gap between the pile head wall 11 and the end face of the truss 2 (precast plate 4) is surrounded by a form (not shown), and underwater concrete is poured into this gap to form the support wall 13 and restrained. Complete pile 3.
After completing the deterrent pile 3, the rubble mound 1
A covering stone 1a is placed on the top of the rubble mound so as to stabilize the mound.

In the breakwater constructed as described above,
Due to the unique shape of the arch-shaped truss 2, the moment generated in each joint 5 is suppressed, and the movement of each truss 2 is restricted by the restraint pile 3. This breakwater has a large wave force even if it is formed to be small and lightweight. It will be well tolerated. Moreover, since the truss 2 has a simple structure using the precast plate 4, it can be easily assembled on-site in a prefabricated form, and the construction cost can be reduced as well as the construction period can be shortened.

In the above embodiment, the joint 5 has the structure in which the mounting member 15 is connected by the spiral rebar 16, but the joint may have the following structure.

That is, the joint 5'shown in FIGS. 7 and 8.
Is provided with a column 22 having a plurality of key grooves 21 in the vertical direction, while a key portion 23 that can be fitted into the key groove 21 is provided on the side surface of each precast plate 4. Then, the inner surface of the key groove 21 and the outer surface of the key portion 23 are reinforced by an iron plate 24 in advance,
First, the pillar 22 is erected on the rubble mound 1, and then the precast plate 4 is assembled while fitting the key portion 23 into the key groove 21, and then the gap between the inner surface of the key groove 21 and the outer surface of the key portion 23. A resin 25 is injected into and the precast plate 4 and the column 22 are fixed. According to such a joint 5 ', since it is not necessary to cast the support wall 13 on site as in the above embodiment, the truss 2 can be constructed with higher efficiency.

In the joint 5 "shown in FIG. 9, one of the plurality of precast plates is used as a parent precast plate 4a, and a three-prong hook 26 is integrally provided on the side surface of the parent precast plate 4a, and the three-prong hook 26 is provided on the side surface of the remaining precast plate 4. A lower mold plate 29 having positioning pins 28 is previously attached to the lower surface of the parent precast plate 4a, and is first mounted on the rubble mound 1 of the parent precast plate 4a. Then, the remaining precast plate 4 is lowered along the parent precast plate 4a while the hook 27 of the precast plate 4 is engaged with the three-pronged hook 26 of the parent precast plate 4a.
28 is placed on the lower template 29 as a guide. After that, the upper mold plate 31 is attached by using the positioning pins 30 provided on the upper surfaces of the precast plates 4 and 4a, the precast plates 4 and 4a are temporarily fixed to each other, and then the hooks 26 and 27 are surrounded. A concrete column 32 is formed by surrounding it with a form (not shown) and pouring underwater concrete into the form. In this case, each hook 2
By providing holes 33 in 6 and 27, hooks 26 and 27
Are firmly connected by concrete columns 32, and a joint 5 ″ as a rigid structure is obtained.

By the way, in the above embodiment, the truss 2
However, the present invention does not limit the number of layers of the truss, and may have a two-layer structure as shown in FIG. 10, for example.

[0019]

As described above in detail, according to the breakwater according to the present invention, the use of the truss structure makes it possible to exert a great breakwater effect even though it is small and lightweight. Combined with the simple structure used, the construction efficiency can be significantly improved and the construction cost can be greatly reduced, and the applicability to deep water can be enhanced. Further, when the interior is filled with a filling material or an arch-shaped truss is adopted, the wave preventing effect is further improved, and the applicability to deep water is significantly enhanced.

[Brief description of drawings]

FIG. 1 is a plan view schematically showing a breakwater according to the present invention.

FIG. 2 is a plan view showing, on an enlarged scale, a part of a truss constituting the breakwater.

FIG. 3 is a plan view showing a joint portion of a truss constituting the present breakwater.

4 is a sectional view taken along the line LL of FIG.

FIG. 5 is a plan view showing a restraint pile that constitutes the present breakwater.

FIG. 6 is a perspective view showing a joint portion of a truss constituting the present breakwater.

FIG. 7 is a perspective view showing another embodiment of the joint forming the present truss.

FIG. 8 is a plan view of the joint shown in FIG.

FIG. 9 is a perspective view showing another embodiment of the joint forming the present truss.

FIG. 10 is a plan view showing another embodiment of the present breakwater.

[Explanation of symbols]

 1 Rubble Mound 2 Truss 3 Restraint Pile 4 Precast Plate 5 Joint 7 Bottom Base 8 Filling Material

Claims (3)

[Claims] 1. A breakwater in which a truss formed by connecting precast plates made of reinforced concrete to each other through a joint is installed on a rubble mound by on-site assembly. 2. The breakwater according to claim 1, wherein a filling material is filled in a room surrounded by the precast plate. 3. The truss has an arch shape in which the convex surface of the truss faces the direction of wave intrusion, and both ends of the truss are supported by restraining piles erected on the rubble mound. breakwater.