Deck roof structure and design method for deck roof structure

Abstract

The interlocking mechanism prevents the deck plates from coming loose if they become deformed. [Solution] A deck roof structure 100 is provided, comprising a deck plate 1 having a pair of left and right fitting ribs, and a tight frame 70 having a plurality of protrusions 71 on which the deck plate 1 is laid, wherein one first fitting rib 4 is provided with a flat first web portion 40, a first flange portion 42 protruding from the first web portion in one direction out of plane, and a first folded portion 43 inclined in the out-of-plane direction of the first flange portion toward the horizontal portion, and the other second fitting rib 5 is provided with a flat second web portion 50 rising in the out-of-plane direction of the horizontal portion 2, a second flange portion 51 protruding from the second web portion in the same direction as the first flange portion, and a second folded portion 52 formed on the second flange portion inclined in the out-of-plane direction of the second flange portion toward the horizontal portion, and the height a of the first folded portion 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 slab) 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 via 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 a fire or the like under the action of a bending moment caused by a load, there is a problem that the amount of deformation increases due to a decrease in the yield strength.

[0005] When the amount of deformation in the cross section increases, the joints between adjacent decks come off, leading to problems such as a roof gap occurring and the expected load support force not being exerted, so it is necessary to avoid this. In addition, when making a fire-resistant roof structure, 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 approval 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" issued by a designated performance evaluation organization and pass the test. As a specific example, a 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 non-conforming.

[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 caused by a fire or the like.

Means for Solving the Problems

[0007] [1] A deck plate having a horizontal portion and a pair of left and right fitting ribs formed at both edges in the width direction of the horizontal portion, and a tight frame having a plurality of convex portions that contact the lower surface of the horizontal portion and on which the deck plate is laid, wherein one of the pair of fitting ribs, the first fitting rib, has a flat plate-shaped first web portion that rises in the out-of-plane direction of the horizontal portion, a first flange portion that projects in one out-of-plane direction from the first web portion, and a first folded-back portion that is formed on the first flange portion and is inclined in the out-of-plane direction of the first flange portion and toward the horizontal portion; the other second fitting rib has a flat plate-shaped second web portion that rises in the out-of-plane direction of the horizontal portion, a second flange portion that projects in the same direction as the first flange portion from the second web portion, and a second folded-back portion that is formed on the second flange portion and is inclined in the out-of-plane direction of the second flange portion and toward the horizontal portion, and a deck roof structure characterized in that the height a of the first folded-back portion is 5.93 mm or more. [2] The deck roof structure according to [1], characterized in that when the in-plane deformation amount of the deck plate is δ and the height of the first folded-back portion is a, δ < a. [3] The deck roof structure according to [1] or [2], characterized in that the deck plate has a plurality of corrugated ribs formed on the horizontal portion and extending in the longitudinal direction, and the height of the corrugated ribs is 4.0 mm or more and 12 mm or less. [4] The deck roof structure according to [1] or [2], characterized in that the deck plate has reinforcing ribs formed on the horizontal portion and extending in the longitudinal direction, and the interval in the width direction between the reinforcing ribs and the fitting 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. [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.

[0008] [7] A deck plate having a horizontal portion and a pair of left and right fitting ribs formed on both edges in the width direction of the horizontal portion, and a plurality of convex portions contacting the lower surface of the horizontal portion, and a tight frame on which the deck plate is laid. Among the pair of fitting ribs, one first fitting rib has a flat plate-shaped first web portion rising in the out-of-plane direction of the horizontal portion, a first flange portion protruding in one out-of-plane direction from the first web portion, and a first flange portion formed on the first flange portion and inclined in the out-of-plane direction of the first flange portion and toward the horizontal portion. The other second fitting rib has a flat plate-shaped second web portion rising in the out-of-plane direction of the horizontal portion, a second flange portion protruding in the same direction as the first flange portion from the second web portion, and a second flange portion formed on the second flange portion and inclined in the out-of-plane direction of the second flange portion and toward the horizontal portion. A design method for a deck roof structure, wherein when the in-plane deformation amount of the deck plate is δ and the height of the first folded-back portion is a, it is designed such that δ < a.

Advantages of the Invention

[0009] According to the present invention, in a deck roof structure in which deck plates are fitted to each other using fitting ribs that fit 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 between 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] This is a cross-sectional view of a deck roof structure with a riser installed between the main frame and the tight frame. [Figure 3] This is a front view of a tight frame according to an embodiment of the present invention. [Figure 4] This is a front view of a deck plate according to an embodiment of the present invention. [Figure 5] This diagram shows how the convex portion of the tight frame contacts the flat portion and the adjacent slanted edge. [Figure 6] This diagram shows a situation where the flat portion of the deck plate is larger than the support surface of the tight frame, resulting in a poor fit. [Figure 7] This is an enlarged view illustrating the angle DPr between the flat portion of the deck plate and the adjacent hypotenuse, and the angle TFr between the inclined surface of the convex portion of the tight frame. [Figure 8] This diagram shows the case where the height TFh of the tight frame is lower than the height DPh of the deck plate 1. [Figure 9] This figure shows how internal deformation occurs in the deck plate of a deck roof structure. [Figure 10] This figure shows the model of the deck plate used in the analysis. [Figure 11] This figure illustrates the amount of intra-sectional deformation δ in a deck plate model. [Figure 12] This graph shows the relationship between the amount of deformation δ within the cross-section of the deck plate and the heating time. [Modes for carrying out the invention]

[0011] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. In this specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions will be 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's frame such as beams and ceilings. As shown in FIG. 1, the deck roof structure 100 has a tight frame 70 fixed to the frame 90 and a deck plate 1 fixed to the tight frame 70.

[0013] The frame 90 of this embodiment is an H-shaped steel consisting of a flange 91 and a web 92. The H-shaped steels extend in a direction orthogonal to the longitudinal direction of the deck plate 1 (the direction along the plane of FIG. 1) and are installed in a plurality at a predetermined interval in the direction orthogonal to the longitudinal direction of the deck plate 1. Also, as shown in FIG. 2, in some cases, light steel shapes, channel steels, etc. are installed as height-adjusting members 93 for aligning the height levels between the frame 90 and the tight frame 70.

[0014] As shown in FIG. 1, the tight frame 70 is a fitting for joining the deck plate 1 and the frame 90, and has a base portion 72 joined to the frame 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 this embodiment has a trapezoidal shape and has a support surface portion 73 that is in surface contact with the deck plate 1 and a slant surface portion 74 that is a slope connecting the support surface portion 73 and the base portion 72. The tight frame 70 is formed of, for example, a strip steel or a galvanized iron sheet with a width of 30 mm to 100 mm and a plate thickness of 2.3 mm to 4.5 mm. This 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 sheet 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 sheet formed into a generally 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 sheet, but generally it is 1.0 m to 13 m.

[0016] As shown in Figures 1 and 4, the deck plate 1 consists of a rectangular flat horizontal section 2, reinforcing ribs 3 projecting vertically (upright) along the longitudinal direction from one side (bottom surface) of the horizontal section 2, and a pair of interlocking left and right interlocking ribs 4 and 5 formed along the edges on both sides of the horizontal section 2 in the deck plate width direction (horizontal direction perpendicular to the extension direction of the reinforcing ribs 3).

[0017] In this embodiment, the deck plate 1 has a single reinforcing rib 3 protruding from the center of the horizontal section 2, and the horizontal section 2 is divided into a first horizontal section 21 and a second horizontal section 22 at this reinforcing rib 3. Of course, there may be multiple reinforcing ribs 3, and the horizontal section 2 may also be divided into three or more sections.

[0018] (Horizontal part) The first horizontal section 21 and the second horizontal section 22 are a pair of flat plate-shaped members positioned on the left and right sides of the reinforcing rib 3, and have irregularities formed along their longitudinal direction by being bent in order to increase bending rigidity and bending strength.

[0019] 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 V-shaped section 24 on the horizontal section 2 that is convex upward. 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.

[0020] A flat plate section 25 is provided between the two V-shaped ribs 23, and the deck plate 1 is supported by the tight frame 70 by the surface contact between the support surface section 73 of the tight frame 70 and the flat plate section 25.

[0021] 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.

[0022] (Reinforcement ribs) The reinforcing rib 3 is vertically installed in the center of one side of the horizontal section 2 (between the first horizontal section 21 and the second horizontal section 22) and consists of a closed section 30 where two flat steel plates overlap, and a reinforcing rib section 31 with a triangular cross-section formed at the tip of this closed section 30. It 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.

[0023] (First mating rib) The first fitting rib 4, which is the right-hand fitting rib of the pair of fitting ribs shown in Figure 4, is composed of a flat plate-shaped first web portion 40 that rises perpendicularly to the plane of the first horizontal portion 21, which is in the out-of-plane direction of the horizontal portion 2; an inclined portion 41 (web portion) that slopes downward inward (towards the side adjacent to the reinforcing rib 3, the same applies hereinafter) from the tip of the first web portion 40 in the state shown in Figure 4; a first flange portion 42 that is horizontally continuous from the tip of the inclined portion 41; a first folded portion 43 that slopes upward from the tip of the first flange portion 42 in the state shown in Figure 4; and a guide inclined portion 44 that slopes in the opposite direction from the first folded portion 43 from the tip of the first folded portion 43. The first flange portion 42 protrudes out of the plane of the first web portion 40 and in the opposite direction to the second fitting rib 5 (one out-of-plane direction). The first folded portion 43 is inclined out of the plane of the first flange portion 42 and toward the horizontal portion 2.

[0024] This first fitting rib 4 has the function of connecting the deck plates 1 together by fitting with the second fitting rib 5 of the adjacent deck plate 1.

[0025] Furthermore, the corners at the joints of the first web section 40, the inclined section 41, the flange section 42, the first folded section 43, and the guide inclined section 44 are all curved and bent to form rounded corners.

[0026] Furthermore, in the deck plate 1 according to the present invention, the inclined portion 41, which is part of the web portion, may not be inclined and may be continuous on the same plane as the first web portion 40, and the guide inclined portion 44, which is part of the flange portion, may not be present. However, even in the deck plate 1 according to the present invention, the first folded portion 43, which is the folded portion of the flange portion, is essential. If the first folded portion 43, which is the folded portion of the flange portion, is present, it becomes possible to lift one of the deck plates and fit the deck plates together.

[0027] (Second mating rib) The second fitting rib 5, which is the left fitting rib of the pair of fitting ribs shown in Figure 4, is composed of a flat plate-shaped second web portion 50 that rises perpendicularly to the plane of the second horizontal portion 22, which is out of the plane of the horizontal portion 2; a second flange portion 51 that slopes inward and downward from the tip of the second web portion 50 in the state shown in Figure 4; and a pressing inclined portion 52 (second folded portion) that slopes upward from the tip of the second flange portion 51 in the state shown in Figure 3. The second flange portion 51 extends out of plane from the second web portion 50 and in the same direction as the first flange portion 42 of the first fitting rib 4. The pressing inclined portion 52 is inclined out of plane from the second flange portion 51 and toward the horizontal portion 2.

[0028] Furthermore, the inclination height of the second flange portion 51 is higher than the inclination height of the first folded portion 43 and the guide inclination portion 44, and the inclination angle of the second flange portion 51 is different from the inclination angle of the first folded portion 43 and the guide inclination portion 44, and is gentler than these inclination angles in the state shown in Figure 3.

[0029] As shown in each figure, similar to the first fitting rib 4, the corners of the second web portion 50, the second flange portion 51, and the pressing inclined portion 52 of the second fitting rib 5 are all curved and bent to form rounded corners.

[0030] In the deck plate according to the present invention, the second flange portion 51 may be horizontal instead of inclined. However, even in the deck plate according to the present invention, the pressing inclined portion 52, which is the folded portion of the second flange portion 51, is essential because it fits with the first folded portion 43 of the first fitting rib 4. In short, in the deck plate according to the present invention, each flange portion must have a folded portion that is inclined out of the plane of the flange portion to prevent it from shifting in the short direction.

[0031] Furthermore, as shown in Figure 4, the horizontal distance D1 between the first web portion 40 of the first fitting rib 4 and the point where the inclination of the first folded portion 43, which is its folded portion, begins is approximately equal to the horizontal distance D2 between the outer surface of the second web portion 50 of the second fitting rib 5 and the outer surface of the point where the inclination of the pressing inclined portion 52, which is its folded portion, begins. Therefore, even if there is some error in the machining accuracy of the inclination angle of the first folded portion 43 and the pressing inclined portion 52, the second fitting rib 5 fits snugly into the first fitting rib 4, and the first web portion 40 and the second web portion 50 come into surface contact.

[0032] 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.

[0033] 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)

[0034] 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)

[0035] 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.

[0036] 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)

[0037] 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).

[0038] 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)

[0039] 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.

[0040] <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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] The inventors believed that the resistance to disengagement was due to the height of the first folded portion 43. In other words, they believed that by increasing the height of the first folded portion 43, disengagement could be avoided even when the deck plate 1 deformed as shown in Figure 9.

[0045] Therefore, the inventors determined the amount of deformation δ within the cross-section 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 first folded portion 43 is a (see Figure 4) and the amount of deformation within the cross-section is δ. δ

[0046] <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.

[0047] 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.

[0048] 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.

[0049] 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)

[0050] 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 fitting ribs 4 and 5. The intra-sectional deformation δ is the amount of vertical deformation of the fitting ribs 4 and 5.

[0051] 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.

[0052] [Table 1]

[0053] 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.

[0054] [Table 2]

[0055] 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 height (mountain-shaped ribs), the amount of deformation δ within the cross section can be reduced, and the height a of the first folded portion 43 can be kept low. Specifically, since the maximum amount of deformation within the cross section when the unevenness is 4 mm or more is 26.2 mm (from the results of Model 3-3), by setting the height a of the first folded portion 43 to 26.2 mm or more, the disengagement of the deck plates from fitting together can be suppressed. 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 a of the first folded portion 43 to 5.93 mm or more is a necessary condition for suppressing the disengagement of the deck plates.

[0056] In the above analysis, the spacing between the reinforcing ribs and the fitting ribs in the width direction 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 between reinforcing ribs and fitting 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 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.

[0057] According to the above embodiment, in a deck roof structure 100 in which deck plates 1 are fitted together, even if the deck plates 1 are deformed due to a temperature rise caused by a fire or the like, it is possible to prevent the deck plates 1 from coming apart.

[0058] 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 a of the first folded section 43 low.

[0059] Similarly, by setting the widthwise spacing between the reinforcing ribs 3 and fitting ribs 4 and 5 of the deck plate 1 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 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 a of the first folded portion 43 can be kept low. [Explanation of symbols]

[0060] 100...Deck roof structure, 1...Deck plate, 2...Horizontal section, 21...First horizontal section, 22...Second horizontal section, 23...V-shaped rib, 24...Mountain-shaped section, 25...Flat section, 26...Hypotenuse, 3...Reinforcement rib, 30...Closing section, 31...Reinforcement rib section, 35...Right-angle bend section, 4...First fitting rib, 40...First web section, 41...Inclined section, 42...First flange section, 43...First fold-over section, 44...Guiding inclined section, 5...Second fitting rib, 50...Second web section, 51...Second flange section, 52...Pressing inclined section (Second fold-over section), 70...Tight frame, 71...Convex section, 72...Base section, 73...Support surface section, 74...Inclined section, 90...Structure, 91...Flange, 92...Web.

Claims

1. A deck plate having a horizontal section and a pair of left and right fitting ribs formed on both edges of the horizontal section in the width direction, The tight frame on which the deck plate is laid has a plurality of protrusions that contact the lower surface of the horizontal section, One of the pair of fitting ribs, the first fitting rib, is provided with a flat, plate-shaped first web portion rising out of the plane of the horizontal portion, a first flange portion extending out of the plane from the first web portion, and a first folded portion formed on the first flange portion and inclined out of the plane of the first flange portion toward the horizontal portion. The other second fitting rib is provided with a flat, plate-shaped second web portion rising out of the plane of the horizontal portion, a second flange portion extending from the second web portion in the same direction as the first flange portion, and a second folded portion formed on the second flange portion and inclined out of the plane of the second flange portion toward the horizontal portion. A deck roof structure characterized in that the height a of the first folded portion is 5.93 mm or more.

2. The deck roof structure according to claim 1, characterized in that δ < a, where δ is the amount of deformation within the cross-section of the deck plate and a is the height of the first folded portion.

3. The deck plate has a plurality of V-shaped ribs formed 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 plate has reinforcing ribs formed 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 distance in the width direction between the reinforcing rib and the fitting rib of the deck plate 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 and a pair of left and right fitting ribs formed on both edges of the horizontal section in the width direction, The tight frame on which the deck plate is laid has a plurality of protrusions that contact the lower surface of the horizontal section, One of the pair of fitting ribs, the first fitting rib, is provided with a flat, plate-shaped first web portion rising out of the plane of the horizontal portion, a first flange portion extending out of the plane from the first web portion, and a first folded portion formed on the first flange portion and inclined out of the plane of the first flange portion toward the horizontal portion. A design method for a deck roof structure, wherein the other second fitting rib is provided with a flat plate-shaped second web portion rising out of the plane of the horizontal portion, a second flange portion extending from the second web portion in the same direction as the first flange portion, and a second folded portion formed on the second flange portion and inclined out of the plane of the second flange portion toward the horizontal portion, 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 first folded portion is a, the structure is designed such that δ < a.

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