Upper floor floor structure

Abstract

To provide a floor structure of an upper-story floor which has a high degree of design freedom without restricting a set position of a partial vertically moved region when a height level of the partial floor of an upper-story floor is relatively moved up and down.SOLUTION: There is provided a floor structure 40 of an upper-story floor of the second story or above in a building 50 of a plurality of stories, in which the floor of the upper-story floor has at least a first floor 21 having a relatively higher level and a second floor 26 having a relatively lower level, each of the first floor 21 and the second floor 26 has a plurality of first floor beams 20 and a second floor beam 25, a ladder type beam 30 is arranged at a boundary between the first floor 21 and the second floor 26, and each of the first floor beam 20 and the second floor beam 25 is connected to the ladder type beam 30.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an upper floor structure. [Background technology]

[0002] There are buildings in which parts of the first floor living room etc. are lowered (recessed). This structure makes the ceiling height in the first floor living room etc. higher, allowing more light to enter the living room etc. from the windows, creating a more open feeling.

[0003] On the other hand, in buildings with two or more floors, there is a demand for a structure in which parts of the floors on the upper floors are lower (or higher) than the other parts. By making parts of the floors of rooms on the upper floors lower than the other parts in this way, the sense of openness in the rooms on the upper floors can be further enhanced, and various usage options can be added to the rooms on the upper floors.

[0004] Here, although this is not a technology related to a floor structure in which the height level of part of the upper floor is relatively low (or high), a skip floor provided, for example, between the first and second floors has been known for some time and is proposed as a skip floor structure in Patent Document 1. This skip floor structure is one in which a belly beam is framed above or below the peripheral floor beam of the skip floor at the same height level as the floor beam of the general floor section, and a transmission beam is interposed at a key point between this belly beam and the peripheral floor beam to transmit horizontal force from the peripheral floor beam to the belly beam. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-166289 A Summary of the Invention [Problem to be solved by the invention]

[0006] When the height level of a part of an upper floor is relatively raised or lowered, in the structural analysis of a building including this upper floor, it is desirable from the viewpoint of structural safety to model the part of the floor that has been raised or lowered as an open-ceiling area in the main frame of the floor. One of the reasons for this is that it is difficult to sufficiently transmit horizontal forces, for example during an earthquake, between the part of the floor that has been raised or lowered relatively and the other parts of the floor.

[0007] In this way, if one were to try to raise and lower part of the floor relatively to further enhance the sense of openness in rooms on the upper floors, in structural analysis this part would be considered an open-air area in the main structure of the floor, and the area that can be raised and lowered relatively would inevitably be limited to the upper floors.

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a floor structure for an upper floor that allows for a high degree of design freedom when the height level of a portion of the floor on the upper floor is relatively raised or lowered, without limiting the setting position of this raised or lowered area. [Means for solving the problem]

[0009] In order to achieve the above object, one aspect of the floor structure of the upper floor according to the present invention is as follows: A floor structure of the second or higher floors in a multi-story building, The upper floor has at least a first floor having a relatively high height level and a second floor having a relatively low height level; the first floor and the second floor each include a plurality of first floor beams and a plurality of second floor beams; A ladder beam is disposed at the boundary between the first floor and the second floor, and the first floor beam and the second floor beam are each connected to the ladder beam.

[0010] According to this aspect, a ladder beam is provided on the upper floor at the boundary between the first floor, which is relatively high, and the second floor, which is relatively low, and the first and second floor beams are connected to the ladder beams, respectively, so that the horizontal force during an earthquake can be sufficiently transmitted from the first floor to the second floor via the ladder beams, which have high rigidity, and therefore, for example, the setting position of the second floor, which is relatively low, can be set at any position without being limited. This is because, since the first and second floor beams are connected to a common ladder beam, it is no longer necessary to consider, for example, the second floor, which is relatively low, as an open-ceiling area in the main frame of the upper floor during structural analysis, and structural analysis can be performed on the entire area of ​​the floor as the main frame.

[0011] This floor structure uses ladder beams, which are generally installed on the vertical structural plane of a building, at the boundary between a first floor and a second floor, which are at different floor heights. This increases the design freedom, so that, for example, the relatively low second floor can be set at various positions on the floor. In addition, the space under the relatively high first floor can be used for underfloor storage, providing options for use in rooms on the upper floors.

[0012] In another aspect of the floor structure of the upper floor according to the present invention, the ladder beam comprises at least an upper chord member, a lower chord member, and a plurality of vertical members connecting the upper chord member and the lower chord member, The first floor beam and the second floor beam are connected to the upper chord and the lower chord, respectively.

[0013] According to this embodiment, the first floor beam is connected to the upper chord that constitutes the ladder beam, the second floor beam is connected to the lower chord that constitutes the ladder beam, and the upper chord and the lower chord are connected to multiple vertical members, so that the horizontal force during an earthquake can be transmitted from one floor beam through one of the upper chord or the lower chord, through multiple vertical members, and through the other of the upper chord or the lower chord to the other floor beam. Here, the ladder beam may be a beam of a Vierendeel structure in which the vertical members are vertical members, or a beam of a structure in which the vertical members include both vertical members and diagonal members.

[0014] It is desirable that the shaped steel material (e.g. H-shaped steel) applied to the first floor beam and the shaped steel material applied to the upper chord to which it is connected are of the same specifications (same dimensions), and it is also desirable that the shaped steel material (e.g. H-shaped steel) applied to the second floor beam and the shaped steel material applied to the lower chord to which it is connected are of the same specifications (same dimensions).In addition, since it is desirable for the vertical member that transmits horizontal forces between the upper chord and the lower chord to be a highly rigid member, it is advisable to use steel pipes or square pipes for this vertical member.

[0015] In addition, in another aspect of the floor structure of the upper floor according to the present invention, a reinforcing plate is attached to the side of the ladder beam from the upper chord to the lower chord, The second floor beam is connected to the lower chord via the reinforcing plate, A reinforcing rib is attached to the wide surface of the reinforcing plate, extending from the upper chord to the upper surface of the second floor beam.

[0016] According to this embodiment, a reinforcing plate is attached extending from the upper chord to the lower chord, and a reinforcing rib is further attached to the wide surface of the reinforcing plate extending from the upper chord to the upper surface of the second floor beam.As a result, the vertical members in particular are reinforced by these reinforcing plates and reinforcing ribs, and a high-strength unit (a unit consisting of vertical members, reinforcing plates, and reinforcing ribs) is formed that contributes to the transmission of horizontal forces between the upper chord and the lower chord.

[0017] Another aspect of the floor structure for the upper floor according to the present invention is characterized in that a first horizontal brace is provided between the plurality of first floor beams, and a second horizontal brace is provided between the plurality of second floor beams.

[0018] According to this aspect, a first horizontal brace is provided between multiple first floor beams, and a second horizontal brace is provided between multiple second floor beams, so that the main frame that constitutes the upper floor is stiffened by each horizontal brace, forming a highly rigid floor structure.

[0019] In another aspect of the floor structure of the upper floor according to the present invention, a load-bearing wall frame is provided on the wall of the lower floor of the building, The ladder beam is characterized in that it has greater rigidity than the load-bearing wall structure.

[0020] According to this aspect, since the ladder beams installed on the floors of the upper floors have a greater rigidity than the load-bearing wall frames installed on the walls of the lower floors of the building, the ladder beams can be modeled as a whole as a rigid beam in the analysis model used for the structural analysis, and the structural analysis can be performed with simple modeling. If the ladder beams have a weak rigidity, deformation may occur in the ladder beam model in the structural analysis, and therefore the structural model needs to accurately reproduce and model the actual structure consisting of the upper chords and the lower chords and the multiple vertical members connecting them, and it takes time to create the analytical model.

[0021] Another aspect of the floor structure for the upper floor according to the present invention is characterized in that only both ends or the vicinity of both ends of the ladder beam are supported by columns of the lower floor.

[0022] According to this embodiment, by applying a ladder beam with high rigidity, only two columns supporting both ends or two points near both ends of the ladder beam are required to be placed on the lower floor, and it is not necessary to place a separate column between the two ends of the ladder beam. Therefore, even if the ladder beam has a large span of, for example, 4P to 8P (P indicates the module, and can be set arbitrarily between 800mm to 1100mm, for example, 910mm wide, depending on the module design specifications), a structure in which two columns support two points near both ends can be applied, so that the floor of the upper floor has a structure with different height levels, and the number of columns on the lower floor supporting this floor can be as small as possible, which increases the spatial freedom of the lower floor. Effect of the Invention

[0023] As can be understood from the above explanation, according to the floor structure for the upper floor of the present invention, when the height level of a portion of the floor of the upper floor is relatively raised or lowered, the setting position of this raised or lowered area is not limited, and it is possible to provide a floor structure for the upper floor with a high degree of design freedom. [Brief description of the drawings]

[0024] [Figure 1] FIG. 2 is a plan view of an example of a floor structure of an upper floor according to an embodiment. [Diagram 2] FIG. 2 is a view taken along the II-II arrows in FIG. 1, and is a longitudinal sectional view taken along the X-axis of an example of a floor structure. [Diagram 3] 3A and 3B are both views taken along the III-III arrows in FIG. 1, where (a) is a longitudinal cross-sectional view along the Y axis of an example of a floor structure, and (b) is a longitudinal cross-sectional view along the Y axis of a modified floor structure. [Figure 4] 4 is a view taken along the arrow IV in FIG. 1. [Diagram 5] 5 is a view taken along the arrow VV in FIG. 4, and is a vertical cross-sectional view perpendicular to the longitudinal direction of an example of a ladder beam. [Figure 6] 6 is a view taken along the arrow VI in FIG. 1, and is a side view explaining the connection structure of the ladder beam, the upper chord, and the lower chord. [Figure 7] FIG. 13 is a side view showing a reinforced ladder beam. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, the floor structure of the upper floor according to the embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, the same reference numerals may be used to designate substantially the same components, and redundant description may be omitted.

[0026] [Upper floor structure according to the embodiment] An example of the floor structure of the upper floor according to the embodiment will be described with reference to Figs. 1 to 7. Here, Fig. 1 is a plan view of an example of the floor structure of the upper floor according to the embodiment. Fig. 2 is a view taken along the arrows II-II in Fig. 1, which is a vertical cross-sectional view along the X-axis of an example of the floor structure, and Figs. 3(a) and (b) are both views taken along the arrows III-III in Fig. 1, Fig. 3(a) is a vertical cross-sectional view along the Y-axis of an example of the floor structure, and Fig. 3(b) is a vertical cross-sectional view along the Y-axis of a modified example of the floor structure. Fig. 4 is a view taken along the arrows IV in Fig. 1, and Fig. 5 is a view taken along the arrows VV in Fig. 4, which is a vertical cross-sectional view perpendicular to the longitudinal direction of an example of a ladder beam. Fig. 6 is a view taken along the arrows VI in Fig. 1, which is a side view explaining a connection structure between the ladder beam, the upper chord, and the lower chord.

[0027] The floor structure 40 of the upper floor shown in FIG. 1 is the floor structure of the second floor of a two-story building 50 shown in FIG. 2. For example, in the case of a three-story building, the floor structure 40 of the illustrated example is applied to the floors of the second and / or third floors. The building 50 of the illustrated example is shown as a building with a rectangular shape in plan view, with its longitudinal direction along the X-axis direction and its transverse direction along the Y-axis direction. In both the longitudinal and transverse directions, a plurality of columns 10 (four in the illustrated example) are erected on the periphery of the building, and between the first floor (1F) and the second floor (2F), a first floor beam 20 constituting a first floor 21 (see FIG. 2) having a relatively high height level and a second floor beam 25 constituting a second floor 26 (see FIG. 2) having a relatively low height level are arranged along the X-axis and Y-axis, respectively. The first floor beam 20 on the periphery of the building 50 becomes a girth.

[0028] As shown in FIG. 2, the floor structure 40 of the illustrated example is divided into three equal parts in the X-axis direction, and the second floor 26 is formed in the central area, and the first floor 21 is formed in the left and right areas. By providing the low-height second floor 26 in the central area, the height s1 to the ceiling of the second floor 26 is high, and a room on the second floor with a sense of openness is formed. Although not shown, there are various configurations of the first floor and the second floor in a plan view. For example, the second floor may be provided only in the left area or only in the right area in FIG. 1, or the second floor may be provided only in one of the nine sections in FIG. 1 or in a plurality of sections separated from each other. In addition, as the configuration of the second floor 26, the illustrated example shows two configurations shown in FIG. 3(a) and (b). First, an example of the floor structure shown in FIG. 3(a) will be described with reference to FIG. 1, FIG. 2, and FIG. 3(a).

[0029] The second floor 26 shown in Figure 3(a) is obtained by further dividing the central area shown in Figure 1 into thirds in the Y-axis direction, and the upper area (upper section) becomes the first floor 21. Therefore, the relatively lower second floor 26 in Figure 1 becomes the A1 area (the lower two sections) indicated by dots in Figure 1.

[0030] A plurality of first horizontal braces 28A are arranged in an intersecting manner on the horizontal structural surface formed by a plurality of first floor beams 20 constituting the first floor 21. Similarly, a plurality of second horizontal braces 28B are arranged in an intersecting manner on the horizontal structural surface formed by a plurality of second floor beams 25 constituting the second floor 26. The horizontal braces 28 are formed, for example, from metal braces, and may have turnbuckles midway along the length.

[0031] As shown in Fig. 2, the first floor beam 20 and the second floor beam 25, which are at different heights, are connected to each other via a ladder beam 30. To explain this with reference to Fig. 1, a ladder beam 30A is disposed along the Y-axis direction at the boundaries between the central region and the left and right regions of the three equal parts divided in the X-axis direction, and both ends of the ladder beam 30A (the upper and lower ends in Fig. 1) are connected to the columns 10.

[0032] In the example shown in Figure 3(a), separate ladder beams 30B, 30C are arranged at positions corresponding to the girder span in the central region and connected to the column 10, and further, a separate ladder beam 30D is arranged at the boundary between the first floor 21 and the second floor 26 in the central region.

[0033] In this way, a ladder beam 30 is arranged at the boundary between the first floor 21 and the second floor 26, which are at different heights, and the first floor beam 20 that constitutes the first floor 21 and the second floor beam 25 that constitutes the second floor 26 are connected to the ladder beam 30.

[0034] Both the first floor beam 20 and the second floor beam 25 are formed from H-shaped steel (an example of shaped steel material) of the same standard, and standards such as H-200×100 and H-250×100 can be applied.

[0035] As shown in Figures 4 and 5, the ladder beam 30 has an upper chord 34A and a lower chord 34B, and multiple (seven in the illustrated example) vertical members 35 arranged between the upper chord 34A and the lower chord 34B and connecting the upper chord 34A and the lower chord 34B.

[0036] Both the upper chord 34A and the lower chord 34B are formed from H-shaped steel, and more specifically, they are formed from H-shaped steel of the same standard as the H-shaped steel that forms the first floor beam 20 and the second floor beam 25, and as shown in Figure 5, both the upper chord 34A and the lower chord 34B have a web 31 and upper and lower flanges 32, 33.

[0037] On the other hand, the vertical members 35 are highly rigid members made of steel pipes, square pipes, or the like, and their upper and lower ends are rigidly joined to the upper chord member 34A and the lower chord member 34B by welding or bolts. In this specification, "welding" refers to appropriate welding selected according to the strength required for the connection and the connection type (rigid connection, pin connection), such as groove welding (full penetration welding, partial penetration welding) and fillet welding.

[0038] As shown in Fig. 4, ladder beams 30 are arranged horizontally to form a component of floor structure 40. As shown in Fig. 4, ladder beams 30 are Vierendeel beams in which vertical members 35 are vertical members. Note that the vertical members may also have diagonal members, and the upper chord member 34A and the lower chord member 34B may be connected by both vertical members and diagonal members.

[0039] 6, an end plate 20a is welded to the end of the first floor beam 20, and an end plate 36 is similarly welded to the end of the upper chord 34A. Both end plates 20a, 36 have bolt holes (not shown) at positions that correspond when they are abutted against each other as in the illustrated example, and bolts 39 are inserted into each bolt hole and tightened to form a bolt connection.

[0040] Meanwhile, an end plate 20a is welded to the end of the second floor beam 25, and an end plate 36 is similarly welded to the end of the lower chord 34B. Bolts 39 are inserted into bolt holes (not shown) that are opened at corresponding positions in both end plates 20a, 36, and bolted together by tightening. Note that the upper chord 34A and first floor beam 20, and the lower chord 34B and second floor beam 25 may each be welded together.

[0041] Also, instead of the connection structure shown in Fig. 6, a reinforcing plate 37 may be attached to the side of the ladder beam 30, spanning from the upper chord 34A to the lower chord 34B, as shown in Fig. 7. In this configuration, the second floor beam 25 is bolted to the lower chord 34B via the reinforcing plate 37. Also, a reinforcing rib 38 is welded to the wide surface of the reinforcing plate 37, spanning from the upper chord 34A to the upper surface of the upper flange 25a of the second floor beam 25. For example, the reinforcing structure shown in the figure is effective when the rigidity of the vertical member 35 is low or when it is desired to further increase the rigidity of the ladder beam 30.

[0042] In this way, the first floor beam 20 and the second floor beam 25, which are at different heights, are connected to the highly rigid ladder beam 30. Therefore, as shown in Fig. 2, when a horizontal force H during an earthquake acts on the building 50, the horizontal force is transmitted in the Z1 direction from one first floor beam 20 (the first floor beam 20 on the left in the illustrated example) to the second floor beam 25 via one ladder beam 30A, and the horizontal force is transmitted in the Z2 direction from the second floor beam 25 to the other first floor beam 20 (the first floor beam 20 on the right in the illustrated example) via the other ladder beam 30A.

[0043] In other words, in a floor structure having floors of different heights, the horizontal force from one of the floor beams that make up each floor can be fully transmitted to the other floor beams via the ladder beams 30. Therefore, in structural analysis of the upper floors, for example, the lower height parts are not considered to be open-air areas in the main structure of the floor, but a structural model can be constructed and structural analysis can be performed by treating all areas as the main structure.

[0044] More specifically, it is desirable that the ladder beam 30 has a greater rigidity than a bearing wall frame (not shown) arranged on the vertical structural surface (wall) of the first floor, for example. Since the ladder beam 30 arranged on the floor of the upper floor has a greater rigidity than the bearing wall frame arranged on the wall of the lower floor of the building, the ladder beam 30 as a whole can be modeled as a rigid beam in the analytical model used for structural analysis, and structural analysis can be performed with simple modeling.

[0045] Furthermore, due to the configuration in which the first floor beam 20 and the second floor beam 25, which are of different heights, are connected via the ladder beam 30, in a floor structure in which the height level of part of the floor of the upper floor rises and falls relatively, the setting position of this rising and falling part is not limited (in the illustrated example, the setting position of the second floor 26 is not limited), resulting in a floor structure with high design freedom.

[0046] Furthermore, by applying the high-rigidity ladder beam 30, structural stability is ensured simply by supporting both ends of the ladder beam 30 with two columns 10, as shown in Figure 1, so there is no need to install additional columns in the middle of the ladder beam 30, thereby increasing the design freedom of the lower floor (the first floor in the illustrated example).

[0047] As shown in Figure 4, the first floor beam 20 (shown as a girder in Figure 4) that constitutes the first floor 21 and the upper chord 34A of the ladder beam 30 are arranged at the same height level, and therefore, the girth around the periphery of the building 50 shown in Figure 1 is formed by the continuity of the first floor beam 20 and the upper chord 34A of the ladder beam 30.

[0048] As shown in Figure 5, the total height t1 of the ladder beam 30 can be set to approximately 500 mm to 800 mm (for example, 600 mm), and when H-200 or H-250 is applied to the upper chord 34A and the lower chord 34B, a square pipe or the like having a height of approximately 100 mm to 300 mm is applied to the vertical member 35.

[0049] In the example shown in Figure 3(a), the central area (see Figure 1) has a first floor 21 and a second floor 26, a ladder beam 30D is disposed at the boundary between the first floor 21 and the second floor 26, and the first floor beam 20 constituting the first floor 21 and the second floor beam 25 constituting the second floor 26 are connected to the ladder beam 30. In addition, various options are provided for the second floor, such as using the space below the relatively high first floor 21 as a storage space 22.

[0050] On the other hand, the example shown in Fig. 3(b) is a configuration in which the upper area (upper section) obtained by dividing the central area (see Fig. 1) into three equal parts is a completely open atrium 27. In this configuration, the horizontal brace 28 shown by the dotted line in Fig. 1 is not necessary.

[0051] In this way, even if there is a void 27 in part of the floor, since the void 27 is surrounded by high-rigidity ladder beams 30, it is possible to perform structural analysis of the entire second floor as the main frame, which increases the freedom in setting the void's location.

[0052] Also, although not shown in the figure, a load-bearing wall structure for a lower floor (first floor in the illustrated example) may be installed below the ladder beam 30, and a load-bearing wall structure for an upper floor (second floor in the illustrated example) may be set above the ladder beam 30.

[0053] In addition, the present invention is not limited to the configuration shown here, and may be implemented in other embodiments in which other components are combined with the configurations and the like of the above-mentioned embodiment. In this regard, the present invention may be modified within the scope of the gist of the present invention, and may be appropriately determined according to the application form. [Explanation of symbols]

[0054] 10: Pillar 20:First floor beam 21: First Floor 22: Storage space 25:Second floor beam 26: Second Floor 28: Horizontal brace 28A: First horizontal brace 28B: Second horizontal brace 30,30A,30B,30C:Ladder beam 31: Web 32,33: Flange 34A:Top chord material 34B: Lower chord 35: Vertical member 36: End plate 37: Reinforcement plate 38: Reinforcement rib 39: Bolt 40, 40A: Floor structure (upper floor structure) 50: Two-story building (building)

Claims

1. A floor structure of the second or higher floors in a multi-story building, The upper floor has at least a first floor having a relatively high height level and a second floor having a relatively low height level; the first floor and the second floor each include a plurality of first floor beams and a plurality of second floor beams; A ladder beam is disposed at the boundary between the first floor and the second floor, and the first floor beam and the second floor beam are each connected to the ladder beam; The ladder beam includes at least an upper chord member, a lower chord member, and a plurality of vertical members connecting the upper chord member and the lower chord member, the first floor beam and the second floor beam are connected to the upper chord and the lower chord, respectively; A reinforcing plate is attached to the side of the ladder beam from the upper chord to the lower chord, The second floor beam is connected to the lower chord via the reinforcing plate, A floor structure for an upper floor, characterized in that a reinforcing rib is attached to the wide surface of the reinforcing plate, extending from the upper chord member to the upper surface of the second floor beam.

2. 2. The floor structure of the upper floor according to claim 1, wherein a first horizontal brace is provided between the first floor beams, and a second horizontal brace is provided between the second floor beams.

3. The walls of the lower floor of the building are provided with a load-bearing wall frame, 3. The floor structure for the upper floor according to claim 1, wherein the ladder beam has a rigidity greater than that of the load-bearing wall structure.

4. 4. The floor structure of the upper floor according to claim 1, wherein only both ends or the vicinity of both ends of the ladder beam are supported by columns of the lower floor.

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