Description

CORRUGATED STEEL SHEET HAVING RATIONAL

JOINTING PART FOR IMPROVEMENT OF COMPRESSIVE

STRENGTH, FLEXIBILITY AND DUCTILITY

Technical Field

[1] The present invention relates to a corrugated multi-plate having an efficient connection for improvement of compressive strength, bending strength and flexural capacity, being applicable to a corrugated multi-plate structure used for constructing and repairing tunnels and bridges by having excellent flexural strength and flexural capacity according to improvement in deformation capacity and compressive strength which denote the capacity of a material to resist a load. Background Art

[2] The present invention relates to a corrugated multi-plate having an efficient connection for improvement of compressive strength, flexural strength and flexural capacity, and more particularly to a corrugated multi-plate applicable to a corrugated multi-plate structure used for constructing and repairing tunnels and bridges, by having excellent flexural strength and flexural capacity according to improvement in deformation capacity and compressive strength which denotes the capacity of a material to resist a load.

[3] Recently, in order to reinforce deteriorated structures like an old tunnel as well as new structures, a corrugated multi-plate structure is used as a substitute for a concrete culvert. As shown in Fig. 1, such a corrugated multi-plate structure is fabricated in an arch shape by connecting corrugated multi-plates 100 comprising ridges 110 and valleys 120 alternately arranged one by one.

[4] Conventionally, to connect the corrugated multi-plates 100, bolts are used at each edge area of the corrugated multi-plates 100. A 2-rows 2-bolts correct arrangement 60 (Fig. 6), a 2-rows 2-bolts incorrect arrangement 70 (Fig. 7), and a 2-rows 4-bolts incorrect arrangement 50 (Fig. 8) have been conventionally used. Here, the '2-bolts' and '4-bolts' means that the number of bolts mounted to a single ridge and a single valley is 2 and 4 respectively. In the 2-rows 2-bolts incorrect arrangement 70, more specifically, each of the ridges 110 and valleys 120 constituting a corrugation of the corrugated multi-plate 100 includes one bolt. In addition, the 2-rows 2-bolts incorrect arrangement 70 comprises two rows of bolts, wherein the row of bolts arranged on the valley 120 is at a further distance from an end of the corrugated multi-plate 100 than the row of bolts arranged on the ridges 110. The 2-rows 4-bolts incorrect arrangement 50 is a mixed form of the 2-rows 2-bolts correct arrangement 60 and the 2-rows 2-bolts

incorrect arrangement 70.

[5] Among the above, the 2-rows 2-bolts correct arrangement 60 shown in Fig. 6 is mainly used, wherein both ridges 110 and valleys 120 each have one bolt. The 2-rows 2-bolts correct arrangement 60 comprises two rows of bolts wherein one row arranged on the ridges 110 is at a further distance from the end of the upper corrugated multi- plate 100 than the other row on the valley 120.

[6] The reason for using the 2-rows 2-bolts correct arrangement in the corrugated multi-plate 100 is that it is possible to guarantee a desired stability of the corrugated multi-plate 100 only under the condition in which the corrugated multi-plate 100 has a flexible-behavior structure such that it is partially deformable during backfilling.

[7] However, such conventional bolt arrangement has limited durability and deformation capacity against a load.

[8] The load deformation capacity of the conventional bolt arrangement is shown by graphs of Figs. 9 and 10, the graphs illustrating an average of measured values experimentally obtained by the inventor. In each graph, a horizontal axis refers to a displacement of the structure whereas a vertical axis refers to a load applied to the corrugated multi-plate. Accordingly, an area below the graph means deformation capacity of the bolt arrangement.

[9] The 2-rows 2-bolts correct arrangement 60 and the 2-rows 2-bolts incorrect arrangement 70 are compared to each other and illustrated by a 2-rows 2-bolts correct arrangement graph 210 and a 2-rows 2-bolts incorrect arrangement graph 220 respectively, as shown in Fig. 9. Referring to Fig. 9, the 2-rows 2-bolts correct arrangement graph 210 has more superior deformation capacity than the 2-rows 2-bolts incorrect arrangement graph 220, since being deformable by up to 300mm even at a 13 ton-f load or more.

[10] Referring to Fig. 10, a 2-rows 4-bolts incorrect arrangement graph 230 has a similar shape with the 2-rows 2-bolts incorrect arrangement graph 220, but has a higher load durability than the 2-rows 2-bolts correct arrangement graph 210. The number of bolts may be increased to supplement the load durability. However, the deformation capacity would be deteriorated when the bolts are added.

[11] More bolts may be used at connections of the corrugated multi-plate 100 to improve the load durability. However, the 2-rows 3-bolts or 2-rows 4-bolts arrangement is not generally used than the 2-rows 2-bolts correct arrangement, since an excessive number of bolts may deteriorate the deformation capacity. As a result, the 2-rows 2-bolts correct arrangement has been mainly used. Disclosure of Invention Technical Problem

[12] Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a corrugated multi-plate applicable to a corrugated multi-plate structure used for constructing and repairing tunnels and bridges, by having excellent flexural strength according to improvement in load durability and deformation capacity, in spite of use of a bolt arrangement having more bolts than a conventional 2-rows 2-bolts correct arrangement.

[13]

Technical Solution

[14] In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a corrugated multi-plate assembly comprising a first corrugated multi-plate including a first plate having ridges and valleys formed in a first direction and thereby forming a corrugation in a second direction perpendicular to the first direction, a first connection area formed at an edge area of the first plate on the first direction, at least two first ridge connections arranged on the ridges within the first connection area, being spaced apart from each other in the first direction, the first ridge connections being at a further distance from an outer end of the first connection area than the first valleys connection which is the closest one to the outer end of the first connection area among the first valley connections; and a second corrugated multi-plate including a second plate having a corrugation corresponding to the corrugation of the first plate, a second connection area formed at an edge area of the second plate on the first direction and overlappingly disposed under the first connection area of the first corrugated multi-plate, and second ridge connections and second valley connections formed at the second connection area and coupled with the first ridge connections and the first valley connections respectively when the first connection area and the second connection area are overlapped, so that the first plate and the second plate are interconnected. Here, an n-th one (n=natural number) of the first ridge connections sequentially spaced apart from the outer end of the first connection area is arranged on the same row as an (n+l)th one of the first valley connections from the outer end of the first connection area in the second direction.

[15] The first ridge connection, the second ridge connection, the first valley connection, and the second valley connection may be implemented by bolt holes for bolt- connection and provided in pairs so that the first plate and the second plate are bolt- connected to each other.

Advantageous Effects

[16] The present invention provides a corrugated multi-plate applicable to a corrugated multi-plate structure used for constructing and repairing tunnels and bridges, by having excellent flexural strength and flexural capacity according to improvement in de-

formation capacity and compressive strength denoting the capacity to resist a load, in spite of use of a bolt arrangement having more bolts than a conventional 2-rows 2-bolts correct arrangement. Brief Description of the Drawings

[17] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: [18] Fig. 1 is a perspective view of a corrugated multi-plate;

[19] Fig. 2 is a plan view of a first corrugated multi-plate according to the embodiment of the present invention; [20] Fig. 3 is a plan view of a second corrugated multi-plate according to the embodiment of the present invention; [21] Fig. 4 is a perspective view of the first and second corrugated multi-plates in connection with each other; [22] Fig. 5 is a sectional view showing the first and the second corrugated multi-plates in connection with each other; [23] Fig. 6 is a plan view showing corrugated multi-plates having a conventional 2-rows

2-bolts correct arrangement, connected with each other; [24] Fig. 7 is a plan view showing corrugated multi-plates having a conventional 2-rows

2-bolts incorrect arrangement, connected with each other; [25] Fig. 8 is a plan view showing corrugated multi-plates having a conventional 2-rows

4-bolts incorrect arrangement, connected with each other; [26] Fig. 9 and Fig. 10 are graphs illustrating the performance of corrugated multi-plates having the conventional bolt arrangements; [27] Fig. 11 is a graph illustrating the performance of a corrugated multi-plate with a

3-rows 4-bolts arrangement according to the embodiment of the present invention; and [28] Fig. 12 through Fig. 14 show processes of constructing a tunnel using a corrugated multi-plate structure fabricated by the corrugated multi-plate according to the embodiment of the present invention.

Mode for the Invention [29] Hereinafter, a corrugated multi-plate according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. [30] A corrugated multi-plate assembly 1 according to the embodiment of the present invention comprises a first corrugated multi-plate 10 and a second corrugated multi- plate 20 respectively shown in Figs. 2 and 3. The first corrugated multi-plate 10 comprises a first plate 11, a first connection area 12, the first valley connections 13,

and the first ridge connections 14.

[31] The first plate 11 is made of metal, and is shaped to have a corrugation by shaping a planar plate such that the planar plate has ridges 110 and valleys 120. As shown in Fig. 2, a first direction A refers to a direction in which the ridges 110 and valleys 120 are extended and a second direction B refers to a direction in which the corrugation is formed. That is, the first direction A and the second direction B are perpendicular to each other.

[32] The first connection area 12 is formed on an edge area of the first plate 11 on the first direction A. The first connection area 12 is disposed on the right of the first plate 11 with reference to Fig. 2. The first connection area 12 is superposed on a second connection area 22 of the second plate 20, thereby forming the corrugated multi-plate assembly 1 as shown in Fig. 5. The second connection area 22 will be described hereinafter.

[33] The first valley connections 13 are arranged on the valleys 120 within the first connection area 12, while being spaced apart from each other in the first direction A. The first valleys connections 13 are coupled with second valleys connections 23 of the second plate 20 that will be explained hereinafter. Each of the valleys 120 within the first connection area 12 may include at least two first valleys connections 13. In this embodiment, as shown in Fig. 2, two first valleys connections 13a and 13b are formed in the first direction A.

[34] The first ridge connections 14 are arranged on the ridges 110 within the first connection area 12, while being spaced apart from each other in the first direction A. The first ridge connections 14 are coupled with second ridge connections 24 of the second plate 20. The second ridge connections 24 will be explained hereinafter. Although more than two first ridge connection pats 14 may be provided, this embodiment includes two first ridge connections 14a and 14b formed in the first direction A as shown in Fig. 2.

[35] Since bolt-connection is most efficient in connecting the first and second corrugated multi-plates 10 and 20, the first valleys connections 13 and the first ridge connections 14 may be implemented by bolt holes.

[36] In addition, as shown in Fig. 2, the first ridge connection 14a is at a further distance from an outer end of the first connection area 12 than the first valley connection 13a. Here, the first ridge connection 14a is the closest to the outer end of the first connection area 12 among the first ridge connections 14, and the first valley connection 13a is the closest to the outer end of the first connection area 12 among the first valley connections 13. When the first connection area 12 and the second connection area 22 are interconnected in an overlapped state and a bending moment occurs in the first and second corrugated multi-plate 10 and 20, the above arrangement

is most advantageous to resist tension applied to the first connection area 12 and the second connection area 22 overlapping each other. This will be explained hereinafter in greater detail.

[37] The second corrugated multi-plate 20 is overlapped and connected with the first corrugated multi-plate 10, under the first corrugated multi-plate 10. Referring to Fig. 3, the second corrugated multi-plate 20 comprises a second plate 21, the second connection area 22, the second ridge connections 24, and the second valley connecti ons 23.

[38] The second plate 21 is made of metal, and has the corrugation structure in a corresponding shape to the corrugation of the first plate 11 of the first corrugated multi- plate 10.

[39] The second connection area 22 is formed on an edge area of the second plate 21 on the first direction A to be capable of overlapping with the first connection area 12 of the first corrugated multi-plate 10.

[40] Since the second corrugated multi-plate 20 is connected to the first corrugated multi-plate 10 through the second connection area 22, as shown in Fig. 3, the first direction A still denotes a direction in which the ridges 110 and valleys 120 are extended and the second direction B still denotes a direction in which the corrugation is formed.

[41] The second connection area 22 is disposed on the left of the second plate 21 with reference to Fig. 2 so that the corrugated multi-plate assembly 1 can be formed as shown in Fig. 5.

[42] The second ridge connections 24 and the second valley connections 23 are provided in corresponding numbers and positions to the first ridge connections 14 and the first valley connections 13 respectively, for connection with the first ridge connections 14 and the first valley connections 13.

[43] Therefore, as shown in Fig. 3, a second valley connection 23a which is the closest one among the second valley connections 23 to an outer end of the second connection area 22, is at a further distance from the outer end of the second connection area 22 than a second ridge connection 24a which is the closest one among the second ridge connections 24 to the outer end of the second connection area 22.

[44] The second valley connections 23 and the second ridge connections 24 each comprise two bolt holes for connection with the first ridge connection 14 and the first valley connection 13.

[45] With the above structure, when the first connection area 12 of the first corrugated multi-plate 10 is superposed on and bolt-connected with the second connection area 22 of the second corrugated multi-plate 20, the corrugated multi-plate assembly 1 of Fig. 4 is fabricated. When a bending moment is applied to the corrugated multi-plate

assembly 1 in an arrowed direction C (Fig. 4), compressive force is generated on an upper portion of each first ridge connection 14 while tensile force is generated at a lower portion of each second valley connection 23.

[46] It is well-known that the tensile force is much more damaging than the compressive force to the corrugated multi-plate. When the bending moment is applied in the direction C, the bolts of the first ridge connections 14 and the second valley connections 23 maintain a connection between the first corrugated multi-plate 10 and the second corrugated multi-plate 20, thereby restraining deformation at all the connections of the first and second corrugated multi-plates 10 and 20.

[47] The fixing force of each bolt demanded for restraining the deformation depends on the position of the bolts. Referring to Fig. 5, the bolt located at a distance S from a reference position, that is the end of the first corrugated multi-plate 10, should prevent the first corrugated multi-plate 10 from pivoting by a degree Q. When the bolt is located at a distance 't' from the reference position, the second corrugated multi-plate 20 should be prevented from pivoting by a degree R. In other words, the further the bolt is located from the reference position, the greater load is applied to the bolt. Therefore, as the distance to the bolts on the valleys 120 from the reference position decreases, the bolt can resist a greater load.

[48] Accordingly, in order to shorten the distance between the bolts and the end of the first corrugated multi-plate 10 for decreasing the tensile force applied to the bolt- connection, the first valley connections 13 are disposed at a shorter distance from the outer end of the first connection area 12 than the position of the first ridge connections 14, as shown in Fig. 2. In addition, as shown in Fig. 3, the second valley connections 23 are disposed at a further distance from the outer end of the second connection area 22 than the position of the second ridge connections 24.

[49] As a result, the first and second ridge connections 14 and 24 and the first and second valley connections 13 and 23 are in a correct bolt arrangement, thereby improving bending rigidity of the corrugated multi-plate assembly 1 to cope with the tensile force.

[50] Since the first and second valley connections 13 and 23 and the first and second ridge connections 14 and 24 are implemented by the bolt holes for bolt-connection, in this embodiment, adjustment of the distance between the first valley connection 13 and the first ridge connection 14 and the distance between the second valley connection 23 and the second ridge connection 24 becomes an essential factor in uniformly distributing the compressive force and the tensile force to the each connection.

[51] Referring to Fig. 2, the first valley connection 13a disposed closest to the outer end of the first connection area 12 is arranged on a first row Z. The first valley connection 13b disposed secondly closest to the outer end and the first ridge connection 14a

disposed closest to the outer end are arranged on a second row Y. The first ridge connection 14b disposed secondly closest to the outer end is arranged on a third row X.

[52] In this case, as shown in Fig. 3, the second ridge connection 24a disposed closest to an outer end of the second connection area 22 is arranged on the first row X. A second ridge connection 24b disposed secondly closest to the outer end and the second valley connection 23a disposed closest to the outer end are arranged on the second row Y. A second valley connection 23b disposed at a second distance is arranged on the third row Z.

[53] As shown in Fig. 5, when the first corrugated multi-plate 10 and the second corrugated multi-plate 20 are connected with each other, one bolts from each of the ridge connections 13 and 23 and the valley connections 14 and 24 are aligned on the middle one of the three rows. In accordance with this bolt arrangement, it is possible to obtain an appropriate minimal interval among the bolts.

[54] Accordingly, the connection structure of the corrugated multi-plate assembly 1 can be in a 3-rows 4-bolts correct arrangement wherein the compressive force and the tensile force are prevented from focusing on a certain one of the ridge connections 14 and 24 or valley connections 13 and 23. In consequence, deformation such as buckling occurred when the distance between the bolts is long can be prevented.

[55] Hereinafter, the flexural strength of the corrugated multi-plate assembly 1 according to the embodiment of the present invention will be described with reference to graphs of Fig. 9 and Fig. 11 illustrating an average of experimentally measured values. In the graphs, a horizontal axis refers to a displacement of the structure whereas a vertical axis refers to a load applied to the corrugated multi-plate structure. Accordingly, an area below the graph refers to deformation capacity of the bolt arrangement.

[56] In Fig. 11, the corrugated multi-plate assembly 1 is compared with the 2-rows

4-bolts incorrect arrangement 50 depicted by a graph 230. Although the 2-rows 4-bolts incorrect arrangement 50 is most competent to resist a great load as compared to other general bolt arrangements, deformation capacity thereof is inferior to the 2-rows 2-bolts correct arrangement 60 due to poor deformation. On the other hand, a 3-rows 4-bolts correct arrangement graph 250 of the corrugated multi-plate assembly 1 according to the embodiment of the present invention has a similar displacement to a 2-rows 2-bolts correct arrangement graph 210 of Fig. 9 even under a greater load than the ultimate load of the 2-rows 4-bolts incorrect arrangement graph 230. That is, deformation capacity of the 3-rows 4-bolts correct arrangement graph 250 is superior to the 2-rows 2-bolts correct arrangement graph 210.

[57] To summarize, the corrugated multi-plate assembly 1 having the 3-rows 4-bolts correct arrangement has a similar deformation capacity to one having the 2-rows 2-bolts correct arrangement 60 while having a superior load durability to the one

having the 2-rows 4-bolts incorrect arrangement 50. Thus, the deformation capacity of the corrugated multi-plate assembly 1 is superior to that of the other conventional bolt arrangements. Accordingly, the corrugated multi-plate assembly 1 is appropriate for a corrugated multi-plate structure used for constructing and repairing a tunnel, a bridge and so on.

[58] Hereinafter, characteristics of the corrugated multi-plate assembly 1 will be explained with reference to Figs. 12 through 14, taking an example of constructing a tunnel using a corrugated multi-plate structure 200 fabricated by the corrugated multi- plate assembly 1.

[59] The process for constructing the tunnel includes first, second, and third processes.

[60] In the first process, the corrugated multi-plate structure 200 fabricated by connecting a plurality of the corrugated multi-plate assembly 1 is installed in a tunnel construction field as shown in Fig. 12.

[61] Since the corrugated multi-plate structure 200 installed in the tunnel construction field has an arch shape, a pressure P is applied on the corrugated multi-plate assembly 1 at a spot 'a' in a direction of laterally widening the corrugated multi-plate structure 200.

[62] Assuming that the pressure P refers to a pressure applied downward from an upper side in Fig. 5, the first corrugated multi-plates 10 and the second corrugated multi- plates 20 at the lateral sides of the corrugated multi-plate structure 200 are applied with the bending moment in the direction C. Here, the corrugated multi-plate assembly 1 has the 3 -rows 4-bolts correct arrangement.

[63] In the second process, soil 210 is banked around the lateral sides of the corrugated multi-plate structure 200 as shown in Fig. 13 after the first process. Here, a pressure P is operated by the soil 210 in a direction of laterally narrowing the corrugated multi- plate structure 200.

[64] In the third process, the soil 210 is banked on an upper part of the corrugated multi- plate structure 200 after the second process.

[65] When the soil 210 is banked up to the upper part of the corrugated multi-plate structure 200, the pressure P is increased. Therefore, the moment applied on the corrugated multi-plate structure 200 is changed as shown by a dotted line 'b' of Fig. 14.

[66] In this state, among the connections 13, 14, 23 and 24 of the corrugated multi-plate assembly 1 disposed at the spot 'a' of Fig. 14, the ridges 110 where compressive force was operated during the first process are applied with tensile force during the third process.

[67] In other words, the pressure P is operated upward from a lower side of Fig. 5.

According to this, the first corrugated multi-plate 10 and the second corrugated multi- plate 20 disposed at the lateral sides of the corrugated multi-plate structure 200 are

applied with the bending moment in the opposite direction of the direction C. Here, tensile force is generated at the ridges 110 while compressive force is generated at the valleys 120 in Fig. 5.

[68] A reference position of the tensile force is an end of the second ridge connection 24 of the second corrugated multi-plate 20, which is disposed right under the first ridge connection 14. The tensile force is subject to a distance 'k' from the reference position to the left one of the first ridge connections 14 in the drawing, namely, the first ridge connection 14b. Therefore, the tensile force generated on the ridges 110 is equalized to the tensile force operated on the corrugated multi-plate assembly 1 of the spot 'a' in the first process. In the third process, the connections 13, 14, 23 and 24 of the corrugated multi-plate assembly 1 are in the 3-rows 4-bolts correct arrangement.

[69] Thus, when used for construction of structures such as a tunnel and a culvert, the corrugated multi-plate assembly 1 according to the embodiment of the present invention can be in the 3-row 4-bolt correct arrangement regardless of the direction of pressures.

[70] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Industrial Applicability

[71] The present invention provides a corrugated multi-plate applicable to a corrugated multi-plate structure used for constructing and repairing tunnels and bridges, by having excellent flexural strength according to improvement in load durability and deformation capacity, in spite of use of a bolt arrangement having more bolts than a conventional 2-rows 2-bolts correct arrangement.