Deck roof structure and design method for deck roof structure

Abstract

This prevents the deck plates from coming apart when they deform due to temperature increases caused by fire or other factors. [Solution] A deck roof structure 100 is provided, comprising a deck plate 1 having a horizontal section 2, a reinforcing rib 3 formed on one edge in the width direction of the horizontal section 2 and having a closing section 30 on the upper side, and a right-angle bent section 35 formed on the other edge in the width direction of the horizontal section 2 and connected to the closing section 30, and a tight frame 70 having a plurality of protrusions 71 that contact the lower surface of the horizontal section 2 and on which the deck plate 1 is laid, wherein the height b of the right-angle bent section 35 of the deck plate 1 is 5.93 mm or more.

Description

Technical Field

[0001] The present invention relates to a deck roof structure constituting a roof of a building and a design method of the deck roof structure.

Background Art

[0002] As a structure using a flat deck plate (roof board) as a roof of a steel-frame building, the one described in Patent Document 1 is known. In the deck roof structure described in Patent Document 1, the deck plate is attached to the frame through a tight frame.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the deck roof structure described in Patent Document 1, the space between the leg-shaped rib portions (reinforcing ribs) of the deck plate may be flat, and when the temperature of the deck plate (steel material) rises due to fire or the like under the action of bending moment due to load, there is a problem that the amount of deformation increases due to the decrease in the bearing strength.

[0005] When the amount of deformation in the cross section increases, the joints between adjacent decks come off, leading to problems such as the roof being unable to exhibit the expected load support force and gaps occurring in the roof, so it is necessary to avoid them. In addition, when making a fire-resistant structure roof, it is necessary to adopt the roof structure described in the Ministry of Construction Notice No. 1399 based on the provisions of Article 2, Paragraph 7 of the Building Standards Law. To obtain the ministerial certification as such a roof structure, it is necessary to conduct a test in accordance with the "Method of Fire and Heat Resistance Performance Test and Evaluation Business" issued by the designated performance evaluation organization and pass the test. As a specific example, flame shielding performance is required, and if a gap or the like occurs in the roof and an event such as fire leakage is confirmed, it will be judged as a failure.

[0006] Therefore, an object of the present invention is to provide a deck roof structure and a design method for the deck roof structure that can prevent the fitting between deck plates from coming off when the deck plate is deformed due to a temperature rise or the like caused by a fire.

Means for Solving the Problems

[0007] [1] A deck plate having a horizontal portion, a reinforcing rib formed at one edge in the width direction of the horizontal portion and having a closing portion on the upper surface side, and a right-angle bending portion formed at the other edge in the width direction of the horizontal portion and connected to the closing portion; and a tight frame having a plurality of convex portions that contact the lower surface of the horizontal portion, on which the deck plate is laid, wherein the height b of the right-angle bending portion of the deck plate is 5.93 mm or more. A deck roof structure characterized by this. [2] When the in-plane deformation amount of the deck plate is δ and the height of the right-angle bending portion is b, the deck roof structure according to [1], characterized in that δ < b. [3] The deck plate has a plurality of the reinforcing ribs extending in the longitudinal direction and a corrugated rib formed between the reinforcing ribs and extending in the longitudinal direction, and the height of the corrugated rib is 4.0 mm or more and 12 mm or less. The deck roof structure according to [1] or [2], characterized by this. [4] The deck roof structure according to [1] or [2], characterized in that the interval in the width direction of the reinforcing ribs of the deck plate is 200 mm or more and 220 mm or less. [5] The deck roof structure according to [1] or [2], characterized in that the plate thickness of the deck plate is 0.8 mm or more and 1.6 mm or less.

[0008] [6] The deck roof structure according to [1] or [2], characterized in that the height of the deck plate is 75 mm or more and 120 mm or less. [7] A deck roof structure design method comprising a deck plate having a horizontal portion, a reinforcing rib formed at one edge in the width direction of the horizontal portion and having a closing portion on the upper surface side, and a right-angle bending portion formed at the other edge in the width direction of the horizontal portion and connected to the closing portion, and a tight frame having a plurality of convex portions that contact the lower surface of the horizontal portion, wherein when the in-plane deformation amount of the deck plate is δ and the height of the right-angle bending portion is b, the deck plate is designed such that δ < b.

Advantages of the Invention

[0009] According to the present invention, in a deck roof structure of a type in which a right-angle bending portion is inserted into a closing portion to fit the deck plates together, even when the deck plates are deformed due to a temperature rise caused by a fire or the like, it is possible to prevent the fitting of the deck plates from coming off.

Brief Description of the Drawings

[0010] [Figure 1] It is a front view showing a state in which the deck roof structure according to an embodiment of the present invention is viewed horizontally along the longitudinal direction of the deck plate. [Figure 2] It is a cross-sectional view of a deck roof structure in which a spacer is installed between the building body and the tight frame. [Figure 3] It is a front view of a tight frame according to an embodiment of the present invention. [Figure 4] It is a front view of a deck plate according to an embodiment of the present invention. [Figure 5] It is a view showing a state in which the convex portion of the tight frame contacts the hypotenuse adjacent to the flat portion. [Figure 6] It is a view showing a state in which the flat portion of the deck plate is larger than the support surface portion of the tight frame and the fit is poor. [Figure 7] It is an enlarged view explaining the angle DPr of the hypotenuse adjacent to the flat portion of the deck plate and the angle TFr of the inclined surface portion of the convex portion of the tight frame. [Figure 8] It is a diagram showing a state when the height TFh of the top frame is lower than the height DPh of the deck plate 1. [Figure 9] It is a diagram showing a state in which in-plane deformation has occurred in the deck plate in the deck roof structure. [Figure 10] It is a diagram showing a model of the deck plate used in the analysis. [Figure 11] It is a diagram for explaining the in-plane deformation amount δ in the model of the deck plate. [Figure 12] It is a graph showing the relationship between the in-plane deformation amount δ of the deck plate and the heating time.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, preferred embodiments of the present invention will be described in detail while referring to the accompanying drawings. In this specification and the drawings, for components having substantially the same functional configuration, the same reference numerals are given and duplicate explanations are omitted.

[0012] The deck roof structure of the present invention constitutes, for example, the roof of a steel-frame building and is provided on the building frame such as beams and main buildings of the building. As shown in FIG. 1, the deck roof structure 100 has a top frame 70 fixed to the frame 90 and a deck plate 1 fixed to the top frame 70.

[0013] The frame 90 of the present embodiment is an H-shaped steel composed of a flange 91 and a web 92. The H-shaped steel extends in a direction orthogonal to the longitudinal direction of the deck plate 1 (the direction along the plane of FIG. 1), and a plurality of them are installed at a predetermined interval in a direction orthogonal to the longitudinal direction of the deck plate 1. Also, as shown in FIG. 2, there is a case where a leveling material 93 such as lightweight steel or channel steel is installed between the frame 90 and the top frame 70 to match the height levels.

[0014] As shown in FIG. 1, the tight frame 70 is a fitting for joining the deck plate 1 and the housing 90, and has a base portion 72 joined to the housing 90 and a plurality of convex portions 71 protruding from the base portion 72. As shown in FIGS. 1 and 3, the convex portion 71 of the tight frame of the present embodiment has a trapezoidal shape and has a support surface portion 73 that makes surface contact with the deck plate 1 and an inclined surface portion 74 that is an inclined surface connecting the support surface portion 73 and the base portion 72. The tight frame 70 is formed of a strip steel, zinc-iron sheet, etc. having a width of, for example, 30 mm to 100 mm and a plate thickness of 2.3 mm to 4.5 mm. The plate thickness is a plate thickness corresponding to thin plates and medium plates that are easy to bend in consideration of manufacturability.

[0015] The deck plate 1 is bent from a thin steel plate of about 0.8 mm to 1.6 mm that has been subjected to rust prevention treatment such as a hot-dip galvanized steel sheet (JIS G3302), and is a steel plate formed into a rectangular shape in plan view with a predetermined length according to the shape of the building. The length of the deck plate 1 varies depending on the thickness of the steel plate, but is generally 1.0 m to 13 m.

[0016] As shown in FIGS. 1 and 4, the deck plate 1 includes a rectangular flat plate-shaped horizontal portion 2 and two reinforcing ribs 3 protruding vertically (vertically) along the longitudinal direction from one side (lower surface) of the horizontal portion 2.

[0017] (Horizontal portion) The horizontal portion 2 is divided into a first horizontal portion 21 and a second horizontal portion 22 on the left and right in the width direction (horizontal direction orthogonal to the extending direction of the reinforcing rib 3). The first horizontal portion 21 and the second horizontal portion 22 are flat plate-shaped members arranged on the left and right of the reinforcing rib 3, and unevenness is formed by being bent along the longitudinal direction to increase bending rigidity and bending strength.

[0018] In the horizontal section 2 according to this embodiment, as shown in Figure 4, two V-shaped ribs 23, which are downward-convex protrusions with a trapezoidal cross-section, are formed on both the first horizontal section 21 and the second horizontal section 22 as irregularities to increase bending rigidity and bending strength. The two V-shaped ribs 23 form a mountain-shaped section 24 on the horizontal section 2 that is convex upward. In other words, the deck plate 1 has a plurality of reinforcing ribs 3 and mountain-shaped sections 24 between the reinforcing ribs 3. The mountain-shaped portion 24 has a horizontal surface, and a flat plate portion 25 is formed between a pair of mountain-shaped ribs 23. Alternatively, both the first horizontal portion 21 and the second horizontal portion 22 may have two mountain-shaped ribs 23 formed thereon, which have a trapezoidal cross-section and are convex upwards relative to the first horizontal portion 21 and the second horizontal portion 22.

[0019] As an example of the irregularities provided on the horizontal section 2, the above-described V-shaped rib 23 was used, but protrusions with a triangular or polygonal cross-section may also be used. In other words, the irregularities provided on the horizontal section 2 may be V-shaped ribs with protrusions or depressions of other shapes, as long as they are irregularities that can be bent along the longitudinal direction to increase bending rigidity and bending strength.

[0020] (Reinforcement ribs) The reinforcing rib 3 is vertically installed on one side of the horizontal section 2 (between the first horizontal section 21 and the second horizontal section 22) and on one edge in the width direction. The reinforcing rib 3 is composed of a joint section 30 where two flat steel plates overlap, and a triangular cross-section reinforcing rib section 31 formed at the tip of this joint section 30, and has the function of improving the bending rigidity and bending strength of the horizontal section 2 in the longitudinal direction. Although the reinforcing rib section 31 is exemplified as having a triangular cross-section, it may also be in the shape of an inverted T or a polygon.

[0021] No reinforcing rib 3 is formed on the other edge of the horizontal section 2; instead, a right-angle bent section 35 is formed that connects to the closing section 30 of the other deck plate 1. In other words, the reinforcing rib 3 on one edge in the width direction of the deck plate functions as an insertable reinforcing rib 3A into which the right-angle bent section is inserted. The reinforcing rib 3A for insertion has the function of connecting deck plates 1 together by inserting the right-angle bent portion 35 of the adjacent deck plate 1 into it.

[0022] Next, the detailed shapes of the deck plate 1 and the tight frame 70 will be described. The detailed shapes described below are primarily intended to suppress misalignment of the deck plate 1 and the tight frame 70 during construction.

[0023] The deck plate 1 is formed such that the flat plate portion 25, which is the horizontal surface of the mountain-shaped portion 24, is in surface contact with the support surface portion 73, which is the horizontal surface of the convex portion 71 of the tight frame 70. Regarding the support surface portion 73 of the flat portion 25 and the convex portion 71 of the deck plate 1, the width dimension DPw of the flat portion 25 and the width dimension TFw of the support surface portion 73 are formed to satisfy equation (1). DPw≧TFw ···(1)

[0024] If equation (1) is not satisfied, that is, if the flat portion 25 of the deck plate 1 is smaller than the support surface portion 73 of the convex portion 71, the convex portion 71 of the tight frame 70 will come into contact with the flat portion 25 and the adjacent hypotenuse 26, as shown in Figure 5, and will not be stable. Furthermore, when joining from above with self-drilling screws or the like, out-of-plane deformation will occur in the deck plate 1, or the self-drilling screws may not reach the tight frame 70, making joining difficult. On the other hand, if the flat portion 25 of the deck plate 1 is extremely large, the arrangement will be as shown in Figure 6, and the effect of suppressing misalignment cannot be expected. Therefore, considering the suppression of construction errors and misalignment, it is desirable to use the dimensions within the range of equation (2). 0mm ≤ DPw - TFw ≤ 10mm ···(2)

[0025] Here, according to JIS G 3352 (Deck Plate), the dimensional tolerance for the effective product width of a deck plate is +8 mm, -2 mm. Since a variation of 10 mm in absolute value is possible, the upper limit of DPw-TFw in equation (2) was set to 10 mm.

[0026] As shown in Figure 7, the angle DPr between the flat portion 25 of the deck plate 1 (mountain-shaped portion 24) and the adjacent hypotenuse 26, and the angle TFr between the inclined surface 74 of the convex portion 71 of the tight frame 70 and the support surface 73 are formed to satisfy equation (3). 10°≦DPr≦TFr≦90° ···(3)

[0027] If the angle DPr on the deck plate 1 side is shallow, the effect of suppressing misalignment cannot be expected. Even considering the frictional resistance generated between the deck plate 1 and the tight frame 70 due to the weight of the deck plate 1, it is desirable that the angle DPr on the deck plate 1 side be at least 10° or more. Furthermore, if the angle TFr on the tight frame 70 side is shallower than the angle DPr on the deck plate 1 side, the protrusion 71 of the tight frame 70 will come into contact with the slanted side 26 of the unevenness of the deck plate 1, resulting in an unstable fit. On the other hand, if the angle TFr on the tight frame 70 side is 90° or more, the tight frame will take on an inverted triangular shape, making it impossible to stably support the load of the deck plate 1. Therefore, it is desirable that angles DPr and TFr satisfy equation (3).

[0028] Furthermore, the height TFh of the tight frame 70 shown in Figure 3 and the height DPh of the deck plate 1 shown in Figure 4 must satisfy equation (4). DPh ≤ TFh ···(4)

[0029] If equation (4) is not satisfied, as shown in Figure 8, the reinforcing rib 3 of the deck plate 1 and the base portion 72 of the tight frame 70 will come into contact, so the deck plate 1 will no longer be supported by the flat plate portion 25, making it difficult to position the deck plate 1. Furthermore, when joining from above with self-drilling screws or the like, out-of-plane deformation may occur in the deck plate 1, or the self-drilling screws may not reach the tight frame 70, making joining difficult.

[0030] <Construction method> Next, the construction method for the deck roof structure 100 described above will be explained. The construction method for the deck roof structure includes a tight frame fixing process and a deck plate laying process.

[0031] In the tight frame fixing process, the base portion 72 of the tight frame 70 is fixed to the structural frame 90 by welding, screws, or other appropriate mounting means. In the deck plate laying process, the deck plate 1 is laid on the tight frame 70 such that the support surface portion 73 of the convex portion 71 of the tight frame 70 is in surface contact with the lower surface of the flat portion 25 of the deck plate 1.

[0032] The method of joining the deck plate 1 and the tight frame 70, and the method of joining the tight frame 70 and the structural frame 90 (purlin) may be by self-drilling screws, fillet welding, or driven rivets.

[0033] Incidentally, the deck plate 1 deforms due to, for example, a temperature rise caused by a fire or the generation of a bending moment due to a load. Figure 9 shows how the deck plate 1 undergoes cross-sectional deformation in the deck roof structure 100. As shown in Figure 9, the cross-sectional deformation of the deck plate 1 causes the adjacent deck plates 1 to become disengaged. The inventors believed that the resistance to disengagement was due to the length of the right-angle bent portion 35. In other words, they thought that by making the right-angle bent portion 35 longer, disengagement could be avoided even when the deck plate 1 deformed as shown in Figure 9.

[0034] Therefore, the inventors determined the amount of internal deformation δ of the deck plate 1 through the analysis described later, and designed the deck plate 1 to satisfy the following equation (5) when the height of the right-angle bend 35 is b (see Figure 4) and the amount of internal deformation δ. δ

[0035] <Calculation of in-section deformation of deck plate through analysis> ​Next, we will explain the analysis performed to calculate the amount of deformation δ within the cross-section of the deck plate. The cross-sectional deformation δ is the deformation confirmed by FEM analysis, which models the deck plate shape and reproduces the temperature rise due to fire and the generation of bending moment due to load. The model was modeled with a unit width of 100 mm, taking symmetry into consideration. For the heating temperature, the temperature distribution of the deck plate was represented in 5 categories based on the results of a heat conduction analysis simulating a fire on the lower floor, and the temperature rise of the deck plate was applied linearly so that the temperature after 30 minutes (1800 seconds) conforms to the ISO standard heating curve. For the load, following the load conditions used in the performance evaluation test for obtaining ministerial certification as a fire-resistant roof conforming to Ministry of Construction Notification No. 1399 (in accordance with the Fire Resistance Performance Test and Evaluation Work Method Manual), 1 m 2 A constant load of 65 kg was applied to each unit.

[0036] In the FEM analysis, as shown in Figure 10, the amount of deformation δ within the cross section was compared by changing the height of the uneven shape (mountain-shaped rib 23) of the horizontal section 2 as a parameter. In other words, the inventors assumed that the amount of deformation δ within the cross section would change depending on the height of the uneven shape, and performed analyses on multiple models with different uneven shapes.

[0037] Figure 10(a) is a model of a deck plate 1 with no irregularities on the horizontal section 2 (Model 1). Figure 10(b) shows a model of deck plate 1 with a ridge height (height of the V-shaped rib 23) of 4 mm (Model 2). Figure 10(c) shows a model of deck plate 1 with a surface height of 8 mm (Model 3). Figure 10(d) shows a model of deck plate 1 with a surface height of 12 mm (Model 4). The height of the unevenness is the vertical distance from the surface (top surface) of the horizontal section 2 of the deck plate 1 to the bottom surface of the V-shaped rib 23. The modeling scope was defined as the area enclosed by the dashed line in Figure 10.

[0038] Furthermore, the parameters listed below were common to all models. Deck plate thickness: 0.8mm Deck plate height DPh: 90mm The deck plate height DPh is the vertical distance from the surface (top surface) of the horizontal section 2 of the deck plate 1 to the bottom surface of the reinforcing rib 3. Support span: 4,000 mm Material: SDP2G (Refer to JIS G 3352 deck plate)

[0039] Figure 11 illustrates the intra-sectional deformation δ in the deck plate model. As shown in Figure 11, the FEM analysis assumes that the center of the horizontal section 2 of the deck plate 1 is supported by a tight frame 70. Due to the center of the horizontal section 2 being supported by the tight frame 70, deformation occurs on the side of the reinforcing rib 3. The intra-sectional deformation δ is the amount of vertical deformation of the reinforcing rib 3.

[0040] Figure 12 is a graph showing the relationship between the amount of internal deformation δ of the deck plate 1 and the heating time. As described above, in the FEM analysis, the temperature rise of the deck plate 1 is applied linearly so that the temperature after 30 minutes (1800 seconds) fits the ISO standard heating curve. As shown in the graph in Figure 12, in the first half, the amount of deformation δ within the cross section decreases as the height of the unevenness increases, but this reverses in part around 1300 seconds from the start of heating, indicating that the deformation performance plateaus with the model having an unevenness height of 4 mm. Table 1 shows the amount of deformation δ within the cross section at 1520 seconds (approximately 25 minutes) from the start of heating.

[0041] [Table 1]

[0042] Furthermore, Table 2 shows the results of varying the deck plate (DP) height and deck plate thickness, and organizing the data in the same way as in Table 1.

[0043] [Table 2]

[0044] The values ​​obtained by dividing the δ for the uneven specification (listed in the far right column) by the δ for the smooth specification are all less than 1, confirming that even when the deck plate height or thickness is changed, there is an effect of suppressing the amount of deformation within the cross-section by about 20-40%. Therefore, by providing unevenness (mountain-shaped ribs), the amount of deformation δ within the cross-section can be reduced, and the height b of the right-angle bent section 35 can be kept small. Specifically, the maximum value of the amount of deformation δ within the cross-section when the unevenness is 4 mm or more is 26.2 mm (from the results of Model 3-3), so by making the height b of the right-angle bent section 35 26.2 mm or more, it is possible to suppress the disengagement of the deck plates from fitting together. On the other hand, the minimum value of the internal deformation δ was 5.93 mm (from the results of Model 3-5), indicating that even when the height of the unevenness is increased and the thickness of the deck plate is maximized, a deformation of 5.93 mm occurs. Therefore, setting the height b of the right-angle bend 35 to 5.93 mm or more is a necessary condition for suppressing the disengagement of the deck plates.

[0045] In the above analysis, the spacing of the reinforcing ribs was assumed to be 200 mm in all cases. However, the amount of deformation δ within the cross-section increases as the spacing increases. While spacing of reinforcing ribs of 200 mm or less is not problematic, if it exceeds 200 mm, it is desirable to limit the increase to about 10% (220 mm) or to adopt it only after conducting special considerations. Special considerations could include, for example, modeling the shape of the deck plate to be used, as in the analysis described above, and calculating the intra-sectional deformation δ by inputting load and heat quantities based on the "Fire Resistance Performance Confirmation Test and Evaluation Procedure Manual," or measuring the intra-sectional deformation δ in a full-scale test. The intra-sectional deformation δ obtained by these methods may be used instead of the intra-sectional deformation δ obtained by the FEM analysis described above.

[0046] According to the above embodiment, in a deck roof structure 100 in which a right-angle bent portion 35 is inserted into a closing portion 30 to fit the deck plates 1 together, even if the deck plates 1 are deformed due to a temperature rise caused by a fire, it is possible to prevent the deck plates 1 from coming apart.

[0047] Furthermore, when a V-shaped rib 23 is provided in the horizontal section 2, the amount of deformation δ within the cross-section can be reduced by setting the height of the V-shaped rib 23 to 4.0 mm or more and 12 mm or less, thereby keeping the height b of the right-angle bent section 35 small.

[0048] Similarly, by setting the spacing of the reinforcing ribs 3 of the deck plate 1 in the width direction to 200 mm or more and 220 mm or less, the thickness of the deck plate 1 to 0.8 mm or more and 1.6 mm or less, and the height of the deck plate 1 to 75 mm or more and 120 mm or less, the amount of deformation δ within the cross section can be reduced, and the height b of the right-angle bent section 35 can be kept small.

[0049] For joining the deck plates 1 together, it is sufficient to simply insert the right-angle bent portion 35 into the closing portion 30 and fit them together. Alternatively, measures to increase resistance to disengagement, as shown in Figure 9, may be taken, such as joining with self-drilling screws if necessary. [Explanation of symbols]

[0050] 100... Deck roof structure, 1... Deck plate, 2... Horizontal section, 3... Reinforcement rib, 21... First horizontal section, 22... Second horizontal section, 23... V-shaped rib, 24... Mountain-shaped section, 25... Flat section, 26... Hypotenuse, 30... Closing section, 31... Reinforcement rib section, 35... Right-angle bend section, 70... Tight frame, 71... Convex section, 72... Base section, 73... Support surface section, 74... Sloping section, 90... Main body, 91... Flange, 92... Web.

Claims

1. A deck plate having a horizontal section, a reinforcing rib formed on one edge of the horizontal section in the width direction and having a closed portion on the upper side, and a right-angle bent portion formed on the other edge of the horizontal section in the width direction and connected to the closed portion, The tight frame on which the deck plate is laid has a plurality of protrusions that contact the lower surface of the horizontal section, A deck roof structure characterized in that the height b of the right-angle bent portion of the deck plate is 5.93 mm or more.

2. The deck roof structure according to claim 1, characterized in that δ < b, where δ is the amount of deformation within the cross-section of the deck plate and b is the height of the right-angle bend.

3. The deck plate has a plurality of reinforcing ribs formed in the horizontal portion and extending in the longitudinal direction, and a V-shaped rib formed between the reinforcing ribs in the horizontal portion and extending in the longitudinal direction. The deck roof structure according to claim 1 or claim 2, characterized in that the height of the V-shaped rib is 4.0 mm or more and 12 mm or less.

4. The deck roof structure according to claim 1 or claim 2, characterized in that the spacing of the reinforcing ribs of the deck plate in the width direction is 200 mm or more and 220 mm or less.

5. The deck roof structure according to claim 1 or claim 2, characterized in that the thickness of the deck plate is 0.8 mm or more and 1.6 mm or less.

6. The deck roof structure according to claim 1 or claim 2, characterized in that the height of the deck plate is 75 mm or more and 120 mm or less.

7. A deck plate having a horizontal section, a reinforcing rib formed on one edge of the horizontal section in the width direction and having a closed portion on the upper side, and a right-angle bent portion formed on the other edge of the horizontal section in the width direction and connected to the closed portion, A method for designing a deck roof structure comprising a tight frame on which the deck plate is laid, having a plurality of protrusions that contact the lower surface of the horizontal section, A method for designing a deck roof structure, characterized in that, if the amount of deformation within the cross-section of the deck plate is δ and the height of the right-angle bend is b, the deck plate is designed such that δ < b.

Images