Rolled H-beam

Abstract

Provided is a rolled H-shaped steel capable of improving the workability of a reinforcing member for civil engineering structures. 【Solution means】The rolled H-shaped steel 10 is a rolled H-shaped steel 10 used as a reinforcing member for civil engineering structures. When the web width-to-thickness ratio rw is defined by Formula (4) using h shown in Formula (5) and the flange width-to-thickness ratio rf is defined by Formula (6), the web width-to-thickness ratio rw and the flange width-to-thickness ratio rf of the rolled H-shaped steel satisfy the conditions of Formula (1), Formula (2), and Formula (3). rw ≧ α1·rf β1 …(1) rw ≦ α2·rf β2 …(2) rw ≦ ξ …(3) rw = h / tw …(4) h = H - 2tf …(5) rf = B / 2tf …(6)

Description

[Technical Field]

[0001] This invention relates to rolled H-beams. [Background technology]

[0002] As a reinforcing member for civil engineering structures, the one shown in Patent Document 1 is known. Patent Document 1 exemplifies a reinforcing ring for a liner plate as a reinforcing member for civil engineering structures. Rolled H-beams are shown as the reinforcing ring. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Utility Model Publication No. 58-10993 [Overview of the project] [Problems that the invention aims to solve]

[0004] The installation of civil engineering structures (such as liner plates as described in Patent Document 1) is often done manually, and with the recent shortage of manpower, there is a need to improve constructability. One way to improve constructability is to lighten the reinforcing members of civil engineering structures. Currently, the reinforcing rings of liner plates are made of wide JIS-H-shaped steel (strength class: 400 N / mm²). 2 Grade steel (e.g., SS400) is used. While medium-width and narrow-width rolled H-beams offer better weight efficiency in terms of bending performance based solely on cross-sectional properties, they significantly increase the load on the rolled H-beams, leading to increased excavation volume. Therefore, wide-width rolled H-beams are used. Consequently, there was a need for a new, wide-width rolled H-beam that would minimize the load on the rolled H-beams, maintain cross-sectional performance (yield strength, rigidity) at or above the current size, and reduce weight as much as possible. This is expected to improve the constructability of reinforcing members in civil engineering structures.

[0005] This invention was made to solve the above-mentioned problems, and aims to provide rolled H-shaped steel that can improve the constructability of reinforcing members for civil engineering structures. [Means for solving the problem]

[0006] The rolled H-shaped steel according to the present invention is a rolled H-shaped steel used as a reinforcing member for civil engineering structures, and when the web width-to-thickness ratio rw is defined in formula (4) using h shown in formula (5) and the flange width-to-thickness ratio rf is defined in formula (6), the web width-to-thickness ratio rw and flange width-to-thickness ratio rf of the rolled H-shaped steel satisfy the conditions of formulas (1), (2), and (3). rw≧α1·rf β1 …(1) rw ≤ α²·rf β2 …(2) rw≦ξ …(3) rw = h / tw …(4) h = H - 2tf …(5) rf = B / 2tf …(6) However, H: depth, B: flange width, tw: web thickness, tf: flange thickness, and the coefficients in equations (1), (2), and (3) are set as follows for each series. The values ​​shown in equations (1) to (6) are obtained from the nominal dimensions H, B, tw, and tf.

[0007] [Table 1]

[0008] In the rolled H-beam according to the present invention, by setting the web width-to-thickness ratio rw and flange width-to-thickness ratio rf of the rolled H-beam to satisfy the conditions of equations (1), (2), and (3), the increase in the depth of the rolled H-beam can be minimized, and the cross-sectional performance (yield strength, rigidity) can be made equal to or better than that of existing wide-width rolled H-beams, while the weight can be reduced by 20% or more. As a result, the constructability of reinforcing members for civil engineering structures can be improved.

[0009] h defined by Equation (5) and b defined by Equation (7) may be specifically set as follows for each series. Note that h and b are values obtained from the nominal dimensions H, B, tw, and tf. b = B - tw …(7) 350W series: h = 358 mm, b = 387 mm 300W series: h = 312 mm, b = 338 mm 250W series: h = 270 mm, b = 290 mm 200W series: h = 222 mm, b = 241 mm 175W series: h = 176 mm, b = 192 mm 150W series: h = 153 mm, b = 167.5 mm 125W series: h = 130 mm, b = 143 mm 100W series: h = 107 mm, b = 118.5 mm

[0010] Note that in order to make the strength and rigidity equivalent or higher and significantly reduce the steel weight, the steel strength is also increased to a higher strength than before, and the steel strength may be 490 N / mm 2 grade.

[0011] As a reinforcing member for civil engineering structures, the rolled H-section steel may be used as a reinforcing ring member of the liner plate or a web stiffener for the gusset. With these reinforcing members, by simply replacing the existing rolled H-section steel with the rolled H-section steel according to the present invention, the workability can be easily improved by significant weight reduction.

Advantages of the Invention

[0012] According to the present invention, it is possible to provide a rolled H-section steel that can improve the workability of the reinforcing member for civil engineering structures.

Brief Description of the Drawings

[0013] [Figure 1] It is a diagram showing a liner plate as a civil engineering structure. [Figure 2]This diagram shows a retaining wall as a civil engineering structure. [Figure 3] This is a cross-sectional view of a rolled H-beam. [Figure 4] This table shows an example of a new size rolled H-beam in the 350W series. [Figure 5] This table shows the dimensions of the new sizes of rolled H-beams in the 350W-200W series. [Figure 6] This table shows the dimensions of the new sizes of rolled H-beams in the 175W-100W series. [Figure 7] Figure 5(a) is a graph plotting the "new size A" to "new size K" of the 350W series rolled H-beams. [Figure 8] This graph plots the new sizes of all 350W-100W series rolled H-beams. [Figure 9] These are schematic diagrams showing the effective cross-section of an H-shaped section in four different cases. [Figure 10] This graph shows the results of the examination of bending strength in various cases for the 350W series. [Figure 11] This graph shows the line that determines the final cross-section related to bending strength in the 350W series. [Figure 12] This graph shows the calculation results for the new size of rolled H-beams in the 350W series. [Figure 13] This graph shows the calculation results for the new size of rolled H-beams in the 300W series. [Figure 14] This graph shows the calculation results for the new size of rolled H-beams in the 250W series. [Figure 15] This graph shows the calculation results for the new size of rolled H-beams in the 200W series. [Figure 16] This graph shows the calculation results for the new size rolled H-beam in the 175W series. [Figure 17] This graph shows the calculation results for the new size rolled H-beam in the 150W series. [Figure 18]This graph shows the calculation results for the new size rolled H-beam in the 125W series. [Figure 19] This graph shows the calculation results for the new size of rolled H-beams in the 100W series. [Figure 20] This graph shows the correspondence between the 350W series and the approximate line for the new size of rolled H-beams. [Figure 21] This graph shows the correspondence between the 300W series and the approximate line for the new size of rolled H-beams. [Figure 22] This graph shows the correspondence between the 250W series and the approximate line for the new size of rolled H-beams. [Figure 23] This graph shows the correspondence between the 200W series and the approximate line for the new size of rolled H-beams. [Figure 24] This graph shows the correspondence between the new size of rolled H-beams in the 175W series and the approximate line. [Figure 25] This graph shows the correspondence between the 150W series and the approximate line for the new size of rolled H-beams. [Figure 26] This graph shows the correspondence between the new size of rolled H-beams in the 125W series and the approximate line. [Figure 27] This graph shows the correspondence between the approximation line and the new size of rolled H-beams in the 100W series. [Figure 28] This graph shows the specified range for the new size rolled H-beam in the 350W series. [Figure 29] This graph shows the specified range for the new size rolled H-beam in the 300W series. [Figure 30] This graph shows the specified range for the new size rolled H-beam in the 250W series. [Figure 31] This graph shows the specified range for the new size rolled H-beam in the 200W series. [Figure 32] This graph shows the specified range for the new size rolled H-beam in the 175W series. [Figure 33] This graph shows the specified range for the new size rolled H-beam in the 150W series. [Figure 34] This graph shows the specified range for the new size rolled H-beam in the 125W series. [Figure 35] This graph shows the specified range for the new size rolled H-beam in the 100W series. [Figure 36] This diagram is used to verify the specified area for rolled H-beams of a new size. [Modes for carrying out the invention]

[0014] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0015] The rolled H-shaped steel according to an embodiment of the present invention is used as a reinforcing member for civil engineering structures. Examples of civil engineering structures to which such reinforcing members are applied include reinforcing rings for liner plates and waling members for earth retaining walls. Figure 1 shows a liner plate 9 as a civil engineering structure. The liner plate 9 shown in Figure 1(a) is curved in an arc shape and is used in earth retaining walls by being joined at the top and bottom. The liner plate 9 has a corrugated steel plate 1 that is curved in an arc shape and a side plate 2 having a plurality of bolt holes 3. A plurality of bolt holes 4 are provided at the top and bottom ends 1' of the corrugated steel plate 1. As shown in Figure 1(b), the liner plate 9 is joined to a reinforcing ring member 5 and a joint plate 6. The reinforcing ring member 5 is a rolled H-shaped steel 10 used as a reinforcing member.

[0016] Figure 2 shows a retaining wall 20 as a civil engineering structure. As shown in Figure 2, the retaining wall 20 is applied to construction and civil engineering sites that require deep excavation, and the excavated area is supported by steel sheet piles 21. Rolled H-beams 10 are used as bracing members 22 to prevent the steel sheet piles 21 from collapsing.

[0017] Figure 3 is a cross-sectional view of a rolled H-beam 10. Rolled H-beams can have either a constant internal cross-section or a constant external cross-section, but the wide rolled H-beams considered in this invention have a constant internal cross-section. With a constant internal cross-section, the rolled H-beams 10 have a constant internal cross-section because they are manufactured using fixed rolls of the same size within the same series.

[0018] The novel rolled H-beam 10 according to this embodiment is intended to be formed using existing fixed rolls, thereby avoiding enormous capital investment in manufacturing.

[0019] In this specification, for comparison purposes, wide-beam rolled H-beams from the 350W series to the 100W series (strength class: 400 N / mm²) are used. 2 Assume a grade of steel. Figure 3 shows "H: depth", "B: flange width", "tw: web thickness", and "tf: flange thickness". Furthermore, "h" is defined by the following equation (5). "b" is defined by the following equation (7). In this case, the web width-to-thickness ratio rw is defined in equation (4) using h, and the flange width-to-thickness ratio rf is defined in equation (6) using B. Note that H, B, tw, and tf are all nominal dimensions. The values ​​shown in equations (4) to (7) are obtained from the nominal dimensions H, B, tw, and tf. rw = h / tw …(4) h = H - 2tf …(5) rf = B / 2tf …(6) b = B - tw …(7)

[0020] [Conditions for evaluation] In the manufacture of the rolled H-beam 10 according to this embodiment, fixed rolls one series higher than those of the comparable wide-width rolled H-beam shall be used. For example, when manufacturing the 350W series rolled H-beam 10, the rolling rolls of the 400W series wide-width rolled H-beam shall be used as the comparable wide-width rolled H-beam. In the following explanations, tables, and formulas, the unit of length shall be "mm" unless otherwise specified. The values ​​of "h" and "b" for each series are shown below. Note that the values ​​of h and b shown below are obtained from the nominal dimensions H, B, tw, and tf. 350W series: h=358mm, b=387mm 300W series: h=312mm, b=338mm 250W series: h=270mm, b=290mm 200W series: h=222mm, b=241mm 175W series: h=176mm, b=192mm 150W series: h=153mm, b=167.5mm 125W series: h=130mm, b=143mm 100W series: h=107mm, b=118.5mm The existing H-beam cross section used for comparison is as follows. The strength class is 400 N / mm². 2 It is a grade. The size is expressed as "H (height) × B (flange width) × tw (web thickness) × tf × (flange thickness)". 350W Series: 350 x 350 x 12 x 19 300W Series: 300 x 300 x 10 x 15 250W Series: 250 x 250 x 9 x 14 200W Series: 200 x 200 x 8 x 12 175W Series: 175 x 175 x 7.5 x 11 150W Series: 150 x 150 x 7 x 10 125W Series: 125 x 125 x 6.5 x 9 100W Series: 100 x 100 x 6 x 8

[0021] The strength of the rolled H-section steel 10 according to this embodiment is 490 N / mm 2 class, which is 1.38 times the design strength of the 400 N / mm 2 class steel of the wide-width rolled H-section steel for comparison. The second moment of area on the strong axis side and the yield bending strength of the rolled H-section steel 10 shall be equal to or greater than those of the wide-width rolled H-section steel for comparison. When calculating the yield bending strength, cross-sections of the rolled H-section steel 10 that do not satisfy the following standard values of formulas (8) and (9) for the width-to-thickness ratio are considered invalid for strength calculation. In considering the cross-sectional dimensions, since the influence of the fillet radius is negligible, the fillet radius is taken as 0.

[0022]

Number

[0023]

Number

[0024] [Trial Calculation Example] Figure 4 is a table showing an example of the study of a new size of the 350W series. Since the upper level of one series of 350W is the 400W series, the rolling of the rolled H-section steel 10 of the new size of the 350W series is premised on rolling with the fixed rolls of the 400W series. At this time, for the internal dimensions, the conditions are set as "h = 358 mm" and "b = 387 mm". In Figure 4, the web thickness is 6 mm, and it is an example in which the flange thickness is changed.

[0025] In this case, the comparison cross-section of the existing size is 350×350×12×19 (400 N / mm 2 class steel). The new size cross-section is studied while keeping the internal dimensions constant at "h = 358 mm" and "b = 387 mm", and also considering the above-mentioned regulations for the width-to-thickness ratio regarding the bending strength. The strength class of the steel material of the new size is 490 N / mm 2 class steel. The 490 N / mm 2 class steel and the 400 N / mm 2The design strength ratio for graded steel is set at 1.38 times.

[0026] In the figure, the I ratio is the ratio of the second moment of area around the strong axis of the cross section to that of a comparison cross section; a ratio greater than 1.0 means that the stiffness is higher than that of the comparison cross section. The My ratio is the ratio of the yield bending strength around the strong axis of the cross section; a ratio greater than 1.0 means that the strength is higher than that of the comparison cross section. In addition, since the target weight reduction rate is 20% or more, it needs to be 0.20 or more. To satisfy these conditions, Figure 4 shows the result of changing the flange while keeping the web thickness constant and the inner dimensions constant at "h=358mm" and "b=387mm".

[0027] "New Size #1" to "New Size #3" have cross-sectional properties ("I ratio" and "My ratio") that are greater than the comparative standard cross-section, but are outside the range because the weight reduction rate is less than 20%. Also, "New Size #15" and "New Size #16" are outside the range because the "I ratio" of their cross-sectional properties is not equal to or greater than that of the comparative standard cross-section. Therefore, in this case, "New Size #4" to "New Size #14" are considered the range of the rolled H-beam 10 according to this embodiment.

[0028] Based on this idea, multiple new sizes of rolled H-beams were established for each of the 350W to 100W series. Figure 5 shows the new sizes for the 350W, 300W, 250W, and 200W series. Figure 6 shows the new sizes for the 175W, 150W, 125W, and 100W series. The flange width-to-thickness ratio and web width-to-thickness ratio for "New Size A" to "New Size K" of the 350W series shown in Figure 5(a) were calculated and plotted on the graph shown in Figure 7. These plots are indicated as "New 350W". Figure 7 also shows existing rolled H-beams for comparison. "JIS-H" is a plot of wide, medium, and narrow rolled H-beams. "Extra Thick H" is a plot of H-beams with a greater thickness than JIS-H-beams. "HY" is a plot of H-beams with a constant outer diameter. "TH" represents a plot of rolled H-beams with special cross-sections manufactured by individual companies. Furthermore, Figure 8 similarly plots all new sizes in the 350W-100W series. It can be seen that the rolled H-beam 10 according to this embodiment has a cross-sectional shape not found in existing rolled H-beams.

[0029] In the rolled H-shaped steel beam 10 according to this embodiment, the range of cross-sectional sizes is defined for each cross-sectional series by the flange width-to-thickness ratio and the web width-to-thickness ratio. The values ​​used in the following analysis are those obtained from the nominal dimensions H, B, tw, and tf.

[0030] [Conditional formula for cross-sectional area] The condition that the cross-sectional area of ​​the section under consideration of the rolled H-beam 10 according to this embodiment is α times the cross-sectional area of ​​the comparative section of the rolled H-beam according to the comparative example is given by equation (10). Rearranging equation (10) with respect to the flange thickness yields equation (11). Substituting h, b, and A1 into equation (11), the required flange thickness tf for each web width thickness tw can be determined. Once the width and thickness of the web portion 11 and the flange portion 12 are determined, h and b are constant values, and therefore the dimensions and shape of the cross-section of the rolled H-beam 10 are determined.

[0031]

number

[0032] [Conditional formula for stiffness] The condition under which the I (second moment of area) of the examined cross-section of the rolled H-beam 10 according to this embodiment is equivalent to that of the comparative cross-section of the rolled H-beam according to the comparative example is given by equation (12). Equation (12) is rearranged in terms of tf. tf is expressed as the solution to the following cubic equation, equation (13). Substituting h, b, and I1 into equation (13), the required flange thickness tf for each web thickness can be determined. Once the width and thickness of the web portion 11 and flange portion 12 are determined, h and b are constant values, thus determining the dimensions and shape of the cross-section of the rolled H-beam 10.

[0033]

number

[0034] [Condition formula for yield strength] Next, we will examine the conditions under which the yield bending strength of the examined cross-section of the rolled H-beam 10 according to this embodiment is equivalent to that of the comparative cross-section of the rolled H-beam according to the comparative example. When the flange width-to-thickness ratio or web width-to-thickness ratio exceeds a certain value, it is necessary to consider the effect of local buckling. Here, we will consider the flange thickness assuming the following four cases. For the same web thickness, the solution is the case in which the plate thickness is the thickest among the flange thicknesses in each case. In the cross-section of the rolled H-beam 10 in Figure 9, the area filled in black is the area considered to be the effective cross-section. Case 1 (Figure 9(a)): Case where the entire cross-section is effective. Case 2 (Figure 9(b)): A case where the entire cross-section of the flange portion 12 is made effective, and the web depth is set to the upper limit of the web width-to-thickness ratio. Case 3 (Figure 9(c)): Case where the flange width is set to the upper limit of the flange width-to-thickness ratio, and the entire cross-section of the web portion 11 is made effective. Case 4 (Figure 9(d)): Case where both flange width and web depth are set to the upper limit of the width-to-thickness ratio.

[0035] The limit values ​​for the width-to-thickness ratio were calculated by applying the evaluation formula from the "Architectural Institute of Japan Steel Structure Design Standards," and the bending strength was estimated by considering sections exceeding the specified width-to-thickness ratio as invalid. Here, the upper limit for the flange width-to-thickness ratio is given by equation (14), and the upper limit for the web width-to-thickness ratio is given by equation (15).

[0036]

number

[0037] The bending strength for Case 1, where the entire cross-section is effective, was calculated using equation (16). Equation (16) is rearranged for tf. tf is expressed as the solution to the following cubic equation, equation (17). Substituting b, My, and F into equation (17), the required flange thickness tf for each web thickness tw can be determined.

[0038]

number

[0039] The bending strength for Case 2, in which the entire cross-section of the flange portion 12 is considered effective and the web depth is set to the upper limit of the width-to-thickness ratio, was calculated using equation (18). Equation (18) is rearranged for tf. tf is expressed as the solution to the following cubic equation, equation (19). By substituting h, b, My, F, and rw into equation (19), the required flange thickness tf for each web thickness tw can be determined.

[0040]

number

[0041] The bending strength for Case 3, in which the flange width is set to the upper limit of the width-to-thickness ratio and the entire cross-section of the web portion 11 is effective, is calculated using equation (20). Equation (20) is rearranged for tf. tf is expressed as the solution to the following quartic equation, equation (21). Substituting h, b, My, F, and rf into equation (21), the required flange thickness tf for each web thickness tw can be determined.

[0042]

number

[0043] The bending strength for Case 4, where both flange width and web depth are set to the upper limit of the width-to-thickness ratio, was calculated using equation (22). Equation (22) is rearranged for tf. tf is expressed as the solution to the following quartic equation, equation (23). Substituting h, b, My, F, rf, and rw into equation (23) gives the required flange thickness tf for each web thickness tw.

[0044]

number

[0045] [Bending strength calculation results for each case] Figure 10 shows the results of the analysis for each case of the 350W series. In each case, the case with the thickest plate thickness is the solution. Therefore, when interpreting the figure, the solution is the case with the smallest flange width-to-thickness ratio for the same web width-to-thickness ratio. As shown in Figure 10, the cross section is determined in Case 3 up to a web width-to-thickness ratio of about 55, and when the web width-to-thickness ratio exceeds 55, the cross section is determined in Case 4. This result was the same for other series as well. Therefore, in the rolled H-beam 10 according to this embodiment, the yield strength only needs to be considered for Case 3 and Case 4. In Figure 11, the graph that determines the final cross section related to bending strength in the 350W series is shown as the graph labeled "Final". The calculation formula for the flange thickness in the combined form of Case 3 and Case 4 is given by the following equations (24) and (25). The flange thickness is expressed as the solution to the following quartic equations (24) and (25).

[0046]

number

[0047] [Results of studies on steel weight reduction, stiffness equivalent, and yield strength equivalent] Figures 12 to 19 show the calculation results for each series from 350W to 100W. The graph for "Weight 20%DN" was obtained from equation (11), the graph for "Stiffness Equivalent" from equation (13), and the graph for "Yield Strength Equivalent" from equations (24) and (25). Since the weight needs to be reduced below the boundary indicated by the "Weight 20%DN" line, the solution lies to the right of the "Weight 20%DN" line. On the other hand, the lines for "Stiffness Equivalent" and "Yield Strength Equivalent" require the plate thickness to be increased from this boundary, and in the figures, the solution lies to the left of both lines. Since both yield strength and stiffness must be satisfied, the further to the left the solution lies, the more it satisfies both yield strength and stiffness. Finally, the area with dashed hatching in Figures 12 to 19 represents the cross-sectional size area of ​​the rolled H-beam 10 according to this embodiment.

[0048] [Approximation] In each series, approximations were made to each graph that determines the cross-sectional size range. For the graph that defines the lower limit of the width-to-thickness ratio, a first approximation line, shown in "Approximate 1," was set. The first approximation line is given by "rw = α1·rf β1 This is shown as follows. A second approximation line, shown in "Approximate 2," was set for the graph that defines the lower limit of the width-to-thickness ratio. The second approximation line is "rw=α2·rf β2 This is indicated as follows. Furthermore, since manufacturing becomes difficult if the web thickness becomes too thick, a web width-to-thickness ratio upper limit value ξ was set here, with a minimum plate thickness of 4 mm as a guideline (rw=ξ). Figures 20 to 27 show the correspondence between the approximation line and the web width-to-thickness ratio upper limit value ξ.

[0049] As shown in Figures 28 to 35, the region defined by the first approximation line, the second approximation line, and the upper limit value ξ of the web width-to-thickness ratio described above was set as the "specified region." The specified region is the region that satisfies the following equations (1), (2), and (3). That is, the web width-to-thickness ratio rw and flange width-to-thickness ratio rf of the rolled H-beam 10 according to this embodiment satisfy the conditions of equations (1), (2), and (3). Note that the width-to-thickness ratios used in equations (1) to (3) are all values ​​obtained from the nominal dimensions H, B, tw, and tf. rw≧α1·rf β1 …(1) rw ≤ α²·rf β2 …(2) rw≦ξ …(3) The coefficients in equations (1), (2), and (3) are set as follows for each series.

[0050] [Table 2]

[0051] [verification] We will now examine the defined region for the rolled H-beam 10 according to this embodiment. Here, we will use the 350W series as an example. In Figure 36(a), the region defined as "the region of the present invention" is the region in which the rolled H-beam 10 is defined in the above-mentioned [approximation]. Figure 36(b) shows the cross-sections at points A to D, and the cross-section of a wide-width rolled H-beam used as a comparative example. As shown in Figure 36(b), at point A, the reduction rate of steel weight is 18%, which falls short of the target reduction rate. At point C, the yield strength is 1.06 times that of the comparative example, but the stiffness is 95%, which is equal to or less than the comparative example. At point D, both the yield strength and stiffness are below the same, and none of the points meet the target. On the other hand, point B, which is within the defined region, satisfies all the conditions. Here, we have explained that the conditions are met within the defined region for the 350W series, but the same applies to other series.

[0052] Next, the operation and effects of the rolled H-shaped steel beam 10 according to this embodiment will be described.

[0053] The rolled H-shaped steel beam 10 according to this embodiment is a rolled H-shaped steel beam 10 used as a reinforcing member for civil engineering structures, and when the web width-to-thickness ratio rw is defined in formula (4) using h shown in formula (5) and the flange width-to-thickness ratio rf is defined in formula (6), the web width-to-thickness ratio rw and flange width-to-thickness ratio rf of the rolled H-shaped steel beam satisfy the conditions of formulas (1), (2), and (3). rw≧α1·rf β1 …(1) rw ≤ α²·rf β2 …(2) rw≦ξ …(3) rw = h / tw …(4) h = H - 2tf …(5) rf = B / 2tf …(6) However, H: height, B: flange width, tw: web thickness, and tf: flange thickness, and the coefficients in equations (1), (2), and (3) are set as follows for each series. Also, the values ​​shown in equations (1) to (6) are all values ​​that can be obtained from the nominal dimensions H, B, tw, and tf.

[0054] [Table 3]

[0055] In the rolled H-shaped steel 10 according to this embodiment, by setting the web width-to-thickness ratio rw and flange width-to-thickness ratio rf of the rolled H-shaped steel to satisfy the conditions of equations (1), (2), and (3), the increase in the depth of the rolled H-shaped steel is minimized, and the cross-sectional performance (yield strength, rigidity) is made equal to or better than that of existing wide-width rolled H-shaped steel, while the weight can be reduced by 20% or more.

[0056] Furthermore, by adopting the rolled H-beam 10 according to this embodiment, transportation efficiency can be increased, contributing to recent transportation problems and CO2 emission reduction. In the description of this embodiment, since it is possible to utilize the fixed rolls of existing wide-width rolled H-beams as the size of the rolled H-beam, there is no need to purchase new rolls, and thus it is possible to obtain the effect of reducing the enormous capital investment costs associated with purchasing such new rolls.

[0057] The values ​​of h defined in equation (5) and b defined in equation (7) may be set as follows in each series. Note that h and b are values ​​obtained from the nominal dimensions H, B, tw, and tf. b = B - tw …(7) 350W series: h=358mm, b=387mm 300W series: h=312mm, b=338mm 250W series: h=270mm, b=290mm 200W series: h=222mm, b=241mm 175W series: h=176mm, b=192mm 150W series: h=153mm, b=167.5mm 125W series: h=130mm, b=143mm 100W series: h=107mm, b=118.5mm

[0058] Furthermore, by maintaining equivalent or superior yield strength and rigidity while significantly reducing the weight of the steel, the steel strength has also been increased compared to conventional materials, reaching 490 N / mm². 2 It was decided that it was acceptable for it to be a lower class.

[0059] As a reinforcing member for civil engineering structures, the rolled H-shaped steel 10 may be used as a reinforcing ring member 5 of a liner plate 9, or as a bracing member 22 of a retaining wall. With these reinforcing members, simply replacing existing rolled H-shaped steel with the rolled H-shaped steel 10 according to this embodiment can easily improve constructability by significantly reducing weight.

[0060] As shown in Figure 8, the rolled H-beam 10 of this embodiment, which is a new size, is located in a region with a large width-to-thickness ratio overall, indicating a new cross-sectional shape. The region is roughly divided into two parts, 350W-200W and 175W-100W. This is because the new cross-section is intended to utilize rolls one size larger, with the beam depth being considered at 50mm intervals for 350W-200W and 25mm intervals for 175W-100W. In the rolled H-beam 10 of this embodiment, the weight of the steel material is reduced by more than 20% compared to conventional rolled H-beams, resulting in easier handling during installation. Furthermore, because it is thinner than conventional rolled H-beams, it improves workability by reducing the effort required for bolt tightening and easing construction constraints on heavy machinery. It also contributes to improving transportation efficiency, addressing recent transportation problems, and reducing CO2 emissions during manufacturing and transportation due to its lighter weight.

[0061] The present invention is not limited to the embodiments described above.

[0062] [Form 1] A rolled H-shaped steel used as a reinforcing member for civil engineering structures, Using h shown in equation (5), the web width-to-thickness ratio rw is defined in equation (4), When the flange width-to-thickness ratio rf is defined in equation (6) using b as shown in equation (7), The rolled H-shaped steel is such that the web width-to-thickness ratio rw and flange width-to-thickness ratio rf satisfy the conditions of equations (1), (2), and (3). rw≧α1·rf β1 …(1) rw ≤ α²·rf β2 …(2) rw≦ξ …(3) rw = h / tw …(4) h = H - 2tf …(5) rf = B / 2tf …(6) However, H: height, B: flange width, tw: web thickness, tf: flange thickness, The coefficients in equations (1), (2), and (3) are set as follows for each series. Also, rw and rf are values ​​obtained from the nominal dimensions H, B, tw, and tf. [Table 4] [Form 2] The rolled H-beam described in Form 1 is defined as follows in each series, where h, as defined in equation (5), and b, as defined in equation (7). Note that h and b are values ​​obtained from the nominal dimensions H, B, tw, and tf. b = B - tw …(7) 350W series: h=358mm, b=387mm 300W series: h=312mm, b=338mm 250W series: h=270mm, b=290mm 200W series: h=222mm, b=241mm 175W series: h=176mm, b=192mm 150W series: h=153mm, b=167.5mm 125W series: h=130mm, b=143mm 100W series: h=107mm, b=118.5mm [Form 3] The steel material has a strength of 490 N / mm². 2 A rolled H-shaped steel beam of the grade described in Form 1 or 2. [Form 4] A rolled H-shaped steel beam according to any one of the forms 1 to 3, used as a reinforcing ring member for a liner plate or as a bracing member for a retaining wall structure in the aforementioned civil engineering structure. [Explanation of symbols]

[0063] 5...Reinforcement ring member, 9...Liner plate, 10...Rolled H-beam, 20...Earth retaining member, 22...Walking member.

Claims

1. A rolled H-shaped steel used as a reinforcing member for civil engineering structures, Using h shown in equation (5), the web width-to-thickness ratio rw is defined in equation (4), When the flange width-to-thickness ratio rf is defined in equation (6), The rolled H-shaped steel is such that the web width-to-thickness ratio rw and flange width-to-thickness ratio rf satisfy the conditions of formulas (1), (2), and (3). rw≧α1・rf β１ …(1) rw≦α2・rf β２ …(2) rw ≤ ξ …(3) rw=h / tw…(4) h=H-2tf...(5) rf=B / 2tf...(6) However, H: height, B: flange width, tw: web thickness, tf: flange thickness, The coefficients in equations (1), (2), and (3) are set as follows for each series. Furthermore, the values ​​shown in equations (1) to (6) are obtained from the nominal dimensions H, B, tw, and tf. Table 1

2. The rolled H-beam according to claim 1, wherein h as defined by formula (5) and b as defined by formula (7) are set as follows in each series. Note that h and b are values ​​obtained from the nominal dimensions H, B, tw, and tf. b=B-tw...(7) 350W series: h=358mm, b=387mm 300W series: h=312mm, b=338mm 250W series: h=270mm, b=290mm 200W series: h=222mm, b=241mm 175W series: h = 176 mm, b = 192 mm 150W series: h = 153 mm, b = 167.5 mm 125W series: h=130mm, b=143mm 100W series: h=107mm, b=118.5mm

3. Steel strength: 490 N / mm ２ A rolled H-shaped steel beam according to claim 1, of the same grade.

4. The rolled H-shaped steel according to claim 1, which is used as a reinforcing ring member of a liner plate or as a bracing member of a retaining wall as the reinforcing member of the civil engineering structure.

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