JPS63151706A - Revetment block and construction of revetment therewith - Google Patents

Abstract

PURPOSE:To permit water-collecting holes to be formed by making porosity variable by a method in which upwardly and downwardly directed hooked connectors which are matched with upwardly and downwardly directed hooked connectors of counter blocks are formed in blocks. CONSTITUTION:Two downwardly turned hooked connectors 11 having connecting projections 11a positioned on sideward face sides which are formed by notching from one side of thickness direction to the other direction in both corners of one sideward direction of a rectangular body 10 and also having connecting rejections 11b on the rear side and upwardly turned hooked connectors having the same shape of connecting projections 12a formed by notching in the opposite direction of the connectors 11 and connecting recesses 12b on the rear are provided. The connectors 11 and 12 are of the same shape with the same dimensions, in which the projections 11a and 12a are matched with the connecting recesses 12b and 11b. Water-collecting holes 17 of different sizes can thus be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a seawall block and a method for constructing a seawall using the same.

(Prior art and its problems) Conventionally, the front, top and back surfaces (1) shown in Figures 1 (a) and (b) have been used as seawalls to prevent storm surges in shallow bays or inland seas.
(2) The so-called three-sided revetment, which is a lining of (3), and the slope-type revetment, which has a high hinterland and uses only the front seam (1) of the three-sided revetment, are known as typical examples. These are intended to protect the hinterland (5) of the seawall (4) by directly blocking the waves running upstream, but recently they have also been adopted as seawalls facing the open sea where high waves attack. I ended up starting it.

However, if such a seawall is installed on a coast that is hit by high waves, the sandy beach in front of the seawall (6) will gradually disappear due to the waves, and the accompanying increase in reflected waves will cause rapid erosion. Proceed to.

This may lead to the complete disappearance of the foreshore, which may eventually lead to the collapse of the seawall.

Therefore, research was conducted to make the waves softer.
A so-called block-stretched gently sloping seawall was developed in consideration of the coastal landscape and use while preserving the foreshore and sedimentation. As shown in FIG. 2(a), this uses a drum-shaped block (7) with a constricted center and provided with a through-water collection hole (7a). For example, first, as shown in Fig. 2, the constriction (7
Stack them so that b) is located in the left and right direction. Next, block rows (8b) and (8c) are created by stacking two blocks so that the wide portions (7c) of each block are located at the left and right constrictions (7b) of the block row (8a). Then, following this procedure, block rows (8d) (8
e) The seawall (9) was constructed as shown in Figure 2 (C), and is intended to preserve the foreshore (6) based on the following principle.

That is, in this method, (1) waves running upstream in front of the seawall as water currents transport sand onto the seawall in a laminar and floating state, and a portion of the sand is captured in the water collection hole (7a); ■ A part of the water flow when the waves return along the seawall surface is allowed to permeate inward of the seawall through the water collection hole (7a), thereby reducing the amount of water flowing down the front of the seawall. 7a) Sedimentation and trapping of sand within. (2) Water based on the water permeation effect of the water collection hole (7a) flows out from the water collection hole (7a) together with the sand later than the water that directly flows down the seawall until the next wave arrives. As a result, sediment is deposited on the front of the lower part of the seawall, and furthermore, the shoreline is moved forward by the sediment, thereby preserving the foreshore.

However, in this seawall, the blocks are interconnected (see Figure 2).
As shown by the arrows in the middle, this is done only in the vertical and horizontal directions of the seawall, and the connection in the direction in which the waves rush, that is, the front and back direction of the seawall, is not maintained.

For this reason, they are likely to be washed away by the force of the waves, and if, for example, two or three pieces are washed away, there is a risk that the entire seawall will be disrupted and destroyed.

In addition, as mentioned above, the sedimentation of sand at the lower part of the front of the seawall is largely related to the water collection holes, whose size depends on the grain size of the sand.

It is necessary to select according to the degree of slope in front of the seawall. Therefore, if the construction points are different, it is necessary to make blocks with water collection holes that meet the conditions of each installation point, but using sauce is disadvantageous from an economical point of view, as it hinders mass production. Furthermore, in this method, as shown in Figure 2 (bl), since the water collection holes (7a) are one vertical line with intervals, the sand carried onto the seawall block is
) is captured on the line where water collection holes (
7a) No acquisition takes place during interval G. Therefore, the disadvantage is that the effect of sedimentation is small and the effect of preserving the foreshore is small.

(Objective of the Invention) The present invention uses blocks of the same size to adjust the size of the required range, for example, with variable porosity of 20 to 30%, and water collection in a staggered arrangement. To provide a block in which holes can be made freely and a method for constructing a seawall using this block, thereby making it possible to economically and reliably preserve the foreshore and hinterland of the seawall.

Next, the present invention will be explained in detail using the drawings.

(Means of the present invention for solving problems) The present invention is the third
As shown in the perspective view of the embodiment shown in Figure <a), it is a rectangular parallelepiped with constant horizontal and vertical lengths and a required thickness (upward and downward hook-shaped joints Q2 of the mating block are located at the four corners of 11).
(A block with a downward hook-shaped joint Go where lυ is matingly connected and an upward hook-shaped joint side is made, and a large number of blocks are combined to construct a seawall with water collection holes arranged in a staggered manner.) .

That is, the block of the present invention has coupling protrusions (lla) located on the lateral surface side, which are provided by cutting out both lateral corners of one side of the rectangular parallelepiped Ql from one surface in the thickness direction to the other surface. two downward hook-shaped coupling parts 0υ, which become coupling recesses (llb), and a coupling protrusion (12a) of the same shape, which is provided by cutting out both horizontal corners of the other in the opposite direction to the downward hook-shaped coupling part αD.
) and a rear coupling recess (12b). In addition, the downward and upward hook-shaped joints α
The downward and upward hook-shaped coupling parts 0I) are made with identical shapes of the same dimensions so that the coupling protrusions (lla) (12a) of now fit and fit into the respective coupling recesses (12b) (llb). It is characterized by the fact that A seawall is constructed by combining and connecting these large numbers of blocks of the same shape according to the following procedure.

In FIG. 3, (llc) (12c) connects the coupling protrusion (, 11a) (12a) to the coupling recess (llb) (1
2b) A guide slope provided to make it easier to drop into the container, and can be omitted.

As shown in Fig. 4(a), blocks (1) and (n) are first positioned at the lower part of the earth embankment surface of the seawall at intervals so that the upward hook-shaped joint α is located on the surface side of the seawall. . And in the coupling recess (12b) of both upward hook-shaped coupling parts @,
The connecting protrusions (lla) of both downward hook-shaped connecting parts αυ of block (III) are dropped, and blocks (1) (n) and (
III). Next, the block facing the front side (
III) both upward hook-shaped joints - joint recess (12b)
Inside, both downward hook-shaped joints α of blocks (IV) and (V)
Drop the connecting protrusion (lla) of υ and form the block (I[
[), (IV) and (V) are combined, and the blocks are then combined in the same manner to form a block surface as shown in FIG. 4(b). Finally, Fig. 4(b) remains on the four circumferential surfaces of the block surface, that is, in the horizontal and vertical directions of the block tension surface.
Fill in the missing part UQ4) in the following manner, for example. That is, it may be filled with concrete, or it may be filled with a filling block a9 for the left and right direction shown in FIG. As shown in (C), blocks (If) (V) and (1') (IV) are created in the same manner as the above block combination.
Insert and fill in the upward and downward joint parts aSaυ,
In addition, the filling block αe1 for the vertical direction shown in FIG. 3(0)
That is, a buried block αe having connecting protrusions (goods) in the same direction at both ends is turned over with its lower side and upper side as shown in FIG. ) by fitting and filling the downward and upward hook-shaped joint αυ sides of the block to complete a block surface having rectangular water collection holes αη.

(Actions and Effects of the Invention) As described above, in the block of the present invention, there are spaces a and b between the connecting portions aυ(2) provided at the four corners, as shown in FIG. 3 ta>. Therefore, when the blocks are connected without creating a gap between each block, the distance a between the downward hook-shaped joint part aυ and the upward hook-shaped joint part side is defined as the length in the vertical direction, as shown in FIG. 4(C). A water collecting hole αη having a horizontal length equal to the distance #b between the downward hook-shaped joints (or between the upward hook-shaped joints) aυ is automatically formed as the blocks are assembled. Moreover, the horizontal length of this water collection hole aη is such that the blocks do not connect to each other without creating a gap as shown in FIG. By shifting and joining in the left-right direction, the length can be freely changed within the range of the width direction of the downward and upward hook-shaped joint parts Qυ(2), that is, the length in the left-right direction.

Therefore, using the same block, water collection holes α of different sizes
By forming η, it is possible to respond to changes in the slope of the seawall and the grain size of the sand. Therefore, it becomes possible to economically construct a seawall that meets the economic requirements, and the drawbacks of conventional blocks are eliminated. At this time, the gaps formed between the blocks may be left as they are or, if necessary, filled with rubble to make them flat.

In addition to this, the connections between blocks in the present invention are as follows:
Not only in the vertical and horizontal directions as in conventional blocks, but also in the forward direction by the lower corners of blocks (IV) and (V), for example, as shown in Fig. 4. Both upper corners of each block are all pressed down by both lower corners of the other blocks, as if they were being held down, and the connection is maintained in the front-rear direction. Therefore, it is possible to reliably prevent the blocks from falling off and being washed away by the force of waves, and it is possible to construct a more solid seawall than that using conventional blocks.

Further, the water collecting holes αη of the present invention are automatically arranged in a staggered manner as shown in FIG. 4(C). Therefore, compared to the conventional block-based revetment described above in Figure 2, the width between adjacent water collection holes is smaller, which improves the sand trapping function and improves the foreshore conservation effect. There is an advantage that the sedimentation function according to the present invention can be improved, as described above.
■ Flowing water (A) when waves (W) run upstream as shown in Figure 5 (a)
The action of the water collection hole aη that sequentially captures (C) part of the sand carried in the bed sweep state and floating state (B) from bottom to top according to the upward flow of the water flow (A). , ■ When the wave (W) returns, as shown in the fifth report, the running water (D) flowing down on the surface of the seawall α is permeated (E), and at the same time, the sand in the running water (D) is moved below the flowing water. The action of water collection holes that sequentially sediment and capture (C) from top to bottom according to the flow, and ■
By repeating the action of the water collection hole an, which allows permeable water (B) to gradually flow down with the sand as a small stream (F) later than the water (D) that flows down on the seawall part A, the lower part is Sand is deposited from the water collection hole toward the upper water collection hole, thereby depositing it on the entire front of the seawall and moving the shoreline forward. Therefore, by arranging the water collecting holes aη in a staggered manner as in the present invention, it is almost the same as creating a block row having further water collecting holes between the block rows having water collecting holes described above in FIG. 2(b). Therefore, no sand is captured (
The sand trapping effect can be improved by reducing the amount of water flowing down.

Next, the sedimentation function according to the present invention will be explained with reference to experimental results shown in FIGS. 6 and 7. Figure 6 (8) (bl (C
) The results are as follows: Sand with a median grain size of 0.27 m was poured into a wave channel with a length of 77 m, a width of 0.9 m, and a height of 1.2 m.
/15 seabed slope and a wave height of 30 (J) at a water depth of 80 cm.
, waves with a period of 2 seconds for 2 hours, 4 hours, 8 hours (local equivalent water depth 16 m, wave height 6 m, period 9 seconds, 9 hours, 18 hours)
The broken line in the figure shows the change in the topography of the natural beach without a seawall, the solid line shows the topography change with the seawall of the present invention, and the dash-dotted line shows the initial slope. As shown in Figure 6 (al (b) (0
), the amount of erosion is gradually increasing as it retreats. On the other hand, the horizontal length is 6Cs%, and the vertical length is 9Cs%.
cll, thickness 31, weight 350g (local equivalent: 1.2m,
When a revetment with a legal slope of 173 is installed near the shoreline using blocks of the present invention (equivalent to 1.8 m, 0.6 m, 2.8 ton), the area near the shoreline is protected by the revetment, as shown by the solid curve, and the main Seawall α due to the sedimentation function developed by the invention
It can be seen that sedimentation is taking place in front of the ridge and the shoreline is moving forward.

Furthermore, FIG. 7 is a diagram showing the classification of two-dimensional topographical changes and the wood grain conditions for determining erosion and sedimentation, which have been tested by many researchers. Type ■ in the figure represents sedimentary landforms, type ■ represents erosional landforms, type ■ represents intermediate landforms, and the boundary values are C-8 and C=4. Also, in the figure, t
anβ is the slope of the seawall, d is the median grain size of the sand, L is the wave wavelength, and H6 is the height of the seawall. Plotting the classification of topographic changes obtained from the experiment in Figure 6 on this figure, we can see that the seawall of the present invention was applied to the eroded wood condition of a natural beach without a seawall, which is shown in the dotted line frame (Go) in the figure. Then, it can be seen that in both cases of 00 (when a seawall is installed on the shoreline) and φ (when a seawall is installed on the land area) surrounded by the solid line in the figure, there is a shift to a sedimentation tendency.

In other words, the erosion area used to be expressed as C=4, but with the construction of the seawall, the hydraulic conditions for the sedimentation process have been expanded, and the foreshore can be protected against high waves that would cause erosion under natural conditions. can be held. For example, a wave height of 30 am on a natural beach.
However, when the seawall according to the present invention is installed, no erosion occurs and the foreshore becomes stable.

[Brief explanation of the drawing]

Fig. 1 (a) (bl is a sectional view showing typical examples of conventional seawalls, Fig. 2 (b) (C) is a perspective view of a conventional block, an explanatory diagram of the construction method, and a construction side view, Third
The figure (al is a perspective view of an embodiment of the block of the present invention, the same figure (bl
(cl is a perspective view of an embodiment of the filling block for the left and right direction and the filling block for the vertical direction, FIG.
(C1 is a perspective view of the construction side, and Fig. 5 (al (b)
6 and 7 are explanatory diagrams of the sedimentation action during the run-up and return of waves, respectively, and FIGS. 6 and 7 are illustrations of experimental examples showing the sedimentation function of the seawall of the present invention. (11(2) (3)... Seawall lining surface, (4)...
Seawall, (5)... hinterland, (6)... foreshore, (7)
... Conventional block, (7a) ... Water collection hole, (7b)
・<Fin part, (7c)...Wide part, (8a) (8
b) (8c) (8d) (8e)...block row,
(9)... Conventional block-clad revetment, (1) (n) ~ (
Vl)...Block of the present invention, α[...cuboid, Ql
)...Downward hook-shaped coupling part, (lla)...Coupling protrusion, (llb)...Coupling recess, side...Upward hook-shaped coupling part, (12a)...Coupling protrusion, ( 12b)...Joining recess, α hot water...Left-right missing part, C4)...Upper-down missing part, Q! 9... Filling block for left and right direction, 01
9... Filling block for vertical direction, Q? )... Water collection hole of the present invention, 0... Seawall of the present invention, α Yu... Sediment, (A
)...Running water when waves run up, (B)...Suspended state of sand, (C)...Sand capture, (D)...Running water falling on the seawall surface, (E)... ...Water permeability, (F) ...Running water (D)
Flowing water with smaller (G)... Water collection hole interval.

Claims (2)

[Claims] (1) A downward hook-shaped joint consisting of a joint protrusion and a joint recess behind the joint protrusion, which are cut out from two corners of one lateral corner of a rectangular parallelepiped from one surface in the thickness direction to the other surface; and an upward hook-shaped joint portion formed by cutting out two corners of both horizontal corners from the surface opposite to the downward hook-shaped joint portion and a joint concave portion provided behind the joint protrusion, and the above-mentioned The downward and upward hook-shaped joints have the same shape so that the respective joint protrusions fit into the respective joint recesses, and the porosity can be varied using the same block by adjusting the joint area of both. Characteristic seawall block. (2) A downward hook-shaped joint consisting of a joint protrusion and a joint recess behind the joint protrusion, which are cut out from two corners of one lateral corner of the rectangular parallelepiped from one surface in the thickness direction to the other surface; and an upward hook-shaped joint portion formed by cutting out two corners of both horizontal corners from the surface opposite to the downward hook-shaped joint portion and a joint concave portion provided behind the joint protrusion, and the above-mentioned first and second revetment blocks in which the downward and upward hook-shaped joints have the same shape so that the respective joint protrusions can fit and fit into the respective joint recesses are arranged in a horizontal direction;
The downward hook-shaped coupling portions on both sides of the third revetment block are combined and connected between the opposing upward hook-shaped coupling portions, and the third
By combining the upward hook-shaped joints on both sides of the revetment blocks with the opposing downward hook-shaped joints of the fourth and fifth revetment blocks, the blocks are sequentially connected in a planar manner to form water collection holes in a staggered arrangement. A method of constructing a seawall, characterized by forming a block-covered surface having the following characteristics.