REVETMENT BLOCK FOR PREVENTING EVACUATION OF SEDIMENT AND CONSTRUCTION METHOD THEREOF

Technical Field

[1] The present invention relates to a revetment block for preventing evacuation of sediment which is constructed on the slope or bottom of seashore, harbor or river or, more particularly to a revetment block for preventing evacuation of sediment which provides a living space for plants and enables convenient and safe access to the natural environment in addition to preventing evacuation of sediment and erosion of the coast and collapse of the embankment resulting therefrom. Background Art

[2] Although many types of revetment blocks have been disclosed in a lot of patents, the conventional revetment blocks are simply constructed on the slope or bottom of seashore, harbor or river, and thus, they do not adequately prevent sediment from being evacuated by swift currents or waves or fully function as environment- friendly revetment blocks.

[3] Specifically, Japanese Patent Laid-Open No. Hei 11-107243 discloses a revetment block without a joining member that connects each revetment block structure with one another. It simply provides a hollow space inside the block in which plants can be grown. Because the individual revetment block structure is not connected with one another, they are not stably fixed during construction, resulting in cost increase.

[4] Japanese Patent Laid-Open No. 2002- 105928, Japanese Patent Laid-Open No.

2003-090022, Korean Patent Publication No. 2002-0020925 and Korean Patent Publication No. 2003-0044558 disclose revetment blocks that can solve the aforementioned problem. However, they need extra joining members to connect the individual revetment block structures.

[5] Whereas the revetment blocks disclosed in WO 03/06040, WO 03/066970 and

Korean Patent Publication No. 2002-0010116 do not require extra joining members for connecting the individual revetment block structures because each revetment block structure is engaged with one another and are resistant to horizontal external forces, they are vulnerable to external forces in the vertical direction like, for example, differential settlement. Disclosure of Invention Technical Problem

[6] As described above, even the revetment blocks adopting the structure of engagement of individual revetment block structures are not stable against the dis-

placement of the ground after construction like, for example, differential settlement.

[7] And, the conventional revetment blocks are just intended to prevent evacuation of sediment settled on the revetment block and to offer a living space for plants. Because they are not equipped with such means as the net for preventing evacuation of sediment presented by the present invention, they do not adequate protection from swift currents and waves.

[8] In addition, the conventional revetment blocks are disadvantageous in cost and period because they required special equipments and processes. Technical Solution

[9] The present invention has been made to solve the afore-mentioned problems and it is an object of the present invention to provide a revetment block being resistant to the displacement of the ground like, for example, differential settlement after construction with the engagement structure of each revetment block structure, offering a living space for plants and being equipped with a means for preventing evacuation of sediment, so that the revetment block is stably fixed to the ground and the evacuation of sediment accumulated on the revetment block can be prevented, and a construction method thereof.

[10] The revetment block for preventing evacuation of sediment in accordance with the present invention is equipped with a means for preventing evacuation of sediment (hereinafter referred to as "net for preventing evacuation of sediment"), along the outer circumference of the revetment block, which can be selected from nylon brush, screen net, rubber pad, etc. depending on the situation. On the outer surface of the block is formed a means for enhancing engagement between each block structure to offer resistance against ground subsidence or displacement by external force. On top of the block is formed an opening at which a bucket or case containing rubbles, plant seeds or soil can be connected for quick plant growth after the construction of the revetment block. Instead of the opening, a pattern resembling the nature may be provided on top of the revetment block.

[11] To be specific, in Claim 1 of the present invention, a revetment block for preventing evacuation of sediment comprising a block structure having a polygonal shape, especially square or circle, in the horizontal direction; an opening for plant growth formed on top of the block structure; and an stepped part formed on the outer circumference of the block structure at which a net for preventing evacuation of sediment can be attached. In the block, the opening has a polygonal, especially square or circular, shape and along the inner circumference of the opening is formed an stepped part that engages with the bucket for plant growth. On the stepped part formed outside the block structure are formed a plurality of threaded holes for fixing the net for

preventing evacuation of sediment with bolts.

[12] The size, strength, raw material, etc. of the net for preventing evacuation of sediment equipped along the outer circumference of the revetment block may be adjusted depending on the situation in order to prevent evacuation of fine sand and soil. The opening on top of the block may be filled with a bucket or case containing rubbles, seeds or soil, so that plants can grow more quickly.

[13] In Claim 2 of the present invention, a revetment block with a net for preventing evacuation of sediment different from that of Claim 1 is provided. In this revetment block, holes are equipped around the opening of the block structure for engagement of the net for preventing evacuation of sediment with the revetment block.

[14] This construction is advantageous in that a damaged or lost net for preventing evacuation of sediment can be replaced with a new one without the need of lifting the revetment block.

[15] In Claim 3 of the present invention, a revetment block in which the opening at which the bucket for plant growth is replaced by a pattern resembling the nature is provided.

[16] This type of revetment block is adequate for the region where plants cannot or need not grow, for example, where the waves are high or the current is swift. The pattern resembling the nature may be adequately selected considering the surroundings.

[17] In Claim 4 of the present invention, a revetment block is provided which is equipped with projections of the center of at least one of the front and rear sides of the block structure and the center of at least one of the left and right sides of the block structure and indentations the center of at least one of the front and rear sides of the block structure and the center of at least one of the left and right sides of the block structure, so that a plurality of revetment blocks can be engaged in one plane, without being displaced horizontally or vertically.

[18] As the projections and the indentations engage with each other, the binding force between the revetment blocks increases. Thus, this construction reduces displacement caused by waves or swift currents and maximized stability. Also, it offers improved resistance to displacement of the ground like, for example, differential settlement, after construction of the revetment block.

[19] In Claim 5 of the present invention, a revetment block is provided with different distance from the top surface of the block structure to the projection(s) and from the top surface of the block structure to the indentation(s) and different length the block structure of each revetment block, so that the revetment block can be constructed in the form of stairs.

[20] This revetment block is useful when a stairs-type construction is required. That is, as revetment blocks with projections and indentations are engaged with difference in

height, a stairs-type revetment block slope can be attained. In this case, it is more effective to use several revetment blocks with different length of block structures.

[21] In Claim 6 of the present invention, a revetment block is provided which is equipped with an opening for plant growth, wherein a plurality of threaded holes are formed on the upper part of the stepped part formed around the inner circumference of the opening for engagement with the bucket for plant growth.

[22] This construction protects the bucket for plant growth from being swept away by swift currents or waves by firmly fixing it to the revetment block with bolts.

[23] In Claim 7 of the present invention, a method for constructing the revetment block for preventing evacuation of sediment of Claim 1, 2 or 3 on the slope or bottom of seashore, harbor or river is provided which comprises the steps of: measuring flow volume, flow rate, wave strength, etc. at the construction site; determining length, shape, size, etc. of the block structure and size, strength, raw material, etc. of the net for preventing evacuation of sediment of the revetment block to be constructed; fixing the revetment block by burying the lower part of the block structure of the revetment block in the slope or bottom of seashore, harbor or river; fixing the net for preventing evacuation of sediment to the block structure, specifically, by fastening up bolts at the threaded holes formed on the upper part of the stepped part outside the block structure or by inserting the case for fixing the net into the indentation formed at the edge of the opening of the block structure; and connecting each of the revetment block horizontally and/or vertically by repeating the foregoing steps.

[24] This construction method enables cost saving and significantly reduces construction period because the revetment block is stably fixed to the ground and each of the revetment block can be simply engaged with each other using the indentations and projections formed on the revetment block.

[25] In Claim 8 of the present invention, a method for constructing the revetment block for preventing evacuation of sediment of Claim 5 on the slope or bottom of seashore, harbor or river in the form of stairs is provided. Basically, the method is identical to the aforementioned method of Claim 7, except that the indentation(s) of one revetment block is engaged with the projection(s) of the other revetment block to form stairs, especially using revetment blocks with block structures having different lengths.

[26] This construction method enables construction of stairs-type revetment blocks simply by using revetment blocks having projections and indentations formed at different heights, or the revetment blocks of Claim 5. It can be more effective, depending on the situation of the construction site, when revetment blocks with block structures having different lengths are used.

Advantageous Effects

[27] The revetment block of the present invention is advantageous in that the binding force between each revetment block is increased by the engagement of the projections and indentations formed on the outer circumference of the revetment block, thereby minimizing displacement by waves or swift currents and maximizing stability. Also, resistance against displacement of the ground like, for example, differential settlement, after construction of the revetment block can be improved, thereby protecting the block from being swept away by swift currents or waves.

[28] Further, the revetment block of the present invention can solve the problem of loss of sand pile at the seashore or river and collapse of embankment due to fast flow rate by using nylon brush, screen net, rubber pad, etc. for preventing evacuation of sediment. That is, evacuation of fine sand and soil can be prevented by adjusting size, strength, raw material, etc. of the nylon brush, screen net, pad, etc. In addition, a living space for plants can be provided by inserting a bucket or case containing rubbles, soil or seeds in the opening at the top of the block.

[29] And, in accordance with the present invention, the revetment block can be constructed at a low construction cost and in short construction period, because each revetment block can be easily connected with other by engaging the indentations and projections without special joining member.

[30] In addition, a stairs-type revetment block can be constructed simply by using revetment blocks having projections and indentations at different heights. Depending on the situation of the construction site, use of several revetment blocks with block structures having different lengths may be more effective. Especially, the present invention is advantageous in that no additional cost is required when constructing a stairs-shaped revetment block. Brief Description of the Drawings

[31] Fig. 1 is a perspective view of the revetment block for preventing evacuation of sediment according to the first embodiment of the present invention, the horizontal cross-section of which has a square shape.

[32] Fig. 2 is the revetment block of Fig. 1 seen from above.

[33] Fig. 3 illustrates the revetment block of Fig. 1 before assembly.

[34] Fig. 4(a) is a cross-sectional side view illustrating the state of insertion of the net for preventing evacuation of sediment. In Fig. 4(b), a nylon brush is inserted as the net for preventing evacuation of sediment. And, in Fig. 4(c), a screen net is inserted as the net for preventing evacuation of sediment.

[35] Fig. 5 is a perspective view of the revetment block for preventing evacuation of sediment according to the first embodiment of the present invention, the horizontal cross-section of which has a circular shape.

[36] Fig. 6 illustrates the revetment block of Fig. 5 in which the bucket for plant growth and the net for preventing evacuation of sediment are inserted.

[37] Fig. 7 (a) is a top view of the revetment block for preventing evacuation of sediment according to the second embodiment of the present invention. Fig. 7(b) is a perspective view of Fig. 7 (a). Fig. 7(c) is a perspective view illustrating the insertion of the bucket for plant growth in the opening for plant growth of the block structure. And, Fig. 7(d) is a perspective view illustrating the engagement of the case holding the net for preventing evacuation of sediment with the opening formed on top of the block structure.

[38] Fig. 8 is a cross-sectional side view of the revetment block for preventing evacuation of sediment according to the second embodiment of the present invention in which the case holding the net for preventing evacuation of sediment is engaged with the opening formed on top of the block structure.

[39] Fig. 9 is a cross-sectional view of the bucket for plant growth inserted into the opening for plant growth of the block structure.

[40] Fig. 10 is a side view of the bolt used to fix the bucket for plant growth and the net for preventing evacuation of sediment to the block structure.

[41] Fig. 11 is a perspective view illustrating an example of a revetment block constructed in accordance with the present invention.

[42] Fig. 12 is a cross-sectional side view illustrating an example of a revetment block constructed in accordance with the present invention.

[43] Fig. 13 is a cross-sectional side view illustrating another example of a revetment block constructed in accordance with the present invention. Best Mode for Carrying Out the Invention

[44] Hereinafter, the present invention is described in further detail referring to the drawings.

[45] Figs. 1 to 6 illustrate the revetment block according to the first embodiment of the present invention. Fig. 1 and Fig. 2 are respectively a perspective view and a top view of the revetment block according to the first embodiment of the present invention. Referring to the figures, the revetment block comprises a block structure (10) having a square cross-section in the horizontal direction. On the outer circumference of the block structure (10) are formed projections (40a) and indentations (40b) for engagement for preventing differential settlement caused by ground subsidence. Fig. 3 illustrates two revetment blocks prior to being assembled with each other by engaging the projections (40a) with the indentations (40b). Also, an stepped part is formed on the outer circumference of the block structure (10), so that a net for preventing evacuation of sediment (50) such as nylon brush, screen net, rubber pad, etc. can be

equipped. On the upper part of the stepped part are formed a plurality (12 in the figure) of threaded holes (90) for fixing a net for preventing evacuation of sediment (50) with bolts (100) (see Fig. 10). On top of the block structure (10) is formed an opening for plant growth (30). The opening (30) has an stepped part (60) which engages with a bucket or case for plant growth (70) (see Fig. 9) that contains rubbles, soil or plant seeds depending on the situation of the construction site. Alternatively, a pattern resembling the nature may be formed on top of the block structure (10) instead of the opening (30). On the upper part of the stepped part (60) are formed a plurality (8 in the figure) of threaded holes (80) for fixing the bucket for plant growth (70) (see Fig. 9) with bolts (100) (see Fig. 10).

[46] Fig. illustrates the state of insertion of the net for preventing evacuation of sediment

(50) in the block structure.

[47] Fig. 5 and Fig. 6 illustrate a revetment block having a circular cross-section in the horizontal direction.

[48] In the revetment block according to the third embodiment of the present invention

(not illustrated), the opening (30) on top of the block structure (10) is replaced by a pattern resembling the nature. This construction is adequate for the region where plants cannot or need not grow. The absence of the opening (30) may contribute to strength enhancement of the block structure (10), and thus this construction is especially useful for the region where the waves are high or the current is swift. The pattern resembling the nature may be adequately selected considering the surroundings.

[49] Fig. 7 and Fig. 8 illustrate the revetment block according to the second embodiment of the present invention. It is different from the revetment block according to the first embodiment in that the net for preventing evacuation of sediment (50) is connected by inserting a case (110) for fixing the net for preventing evacuation of sediment in an groove (120) formed on top of the block structure (10) rather than using the bolts (100).

[50] The revetment block of the present invention may be made from a variety of raw materials, including concrete, composite materials recycled from industrial byproducts, PE, etc.

[51] Figs. 11 to 13 illustrate examples of the construction of the revetment block in accordance with the present invention. Fig. 11 and Fig. 12 illustrate the construction example in which the net for preventing evacuation of sediment (50) is joined at the outer circumference of the block structure (10). The net for preventing evacuation of sediment (50) may be selected from nylon brush, screen net, rubber pad, etc. depending on the situation of the construction site and its size, shape or kind also may be selected considering the situation of the construction site and the water flow direction. The length, size, shape, etc. of the block structure (10) of the revetment

block may be selected depending on the situation of the construction site. Each revetment block may be connected in the vertical and/or horizontal direction by engaging the projections (40a) with the indentations (40b), in order to secure stability even when external force is applied or ground subsidence takes place. The net for preventing evacuation of sediment (50) bound to the block structure (10) prevents the sediment accumulated on the block structure (10) from being swept away by swift currents or waves, thereby enabling stable plant growth.

[52] Fig. 13 illustrates a construction example in which revetment blocks with projections (40a) and indentations (40b) formed at different heights are constructed in the form of stairs by engaging the projections (40a) with the indentations (40b). In the figure, the case (110) for fixing the net for preventing evacuation of sediment is inserted in the groove (120) formed on top of the block structure (10) to join the net for preventing evacuation of sediment (50). However, the net for preventing evacuation of sediment (50) may be joined using the bolts (100). In this stairs-type construction, it is more effective to use revetment blocks block structures (10) having different lengths. Industrial Applicability

[53] While the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that various modifications and substitutions can be made thereto without departing from the spirit and scope of the present invention as set forth in the appended claims.