JP2012132165A - Floor structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floor structure capable of improving its performance to interrupt floor impact sounds independently of the shape and size of slabs.SOLUTION: The floor structure includes a floor slab 40 having opposed two sides fixed by first beams 20 which connect between a plurality of columns 10 in the span direction and second beams 30 which extend in the ridge direction and connect between the columns 10, respectively. On the face of the floor slab 40 encircled by the first beams 20 and the second beams 30, a projecting part 41 is provided which projects including a belly region of a vibration mode on the face of the encircled floor slab 40 and extends in a wavy shape from the belly region of the vibration mode toward the periphery of the face of the encircled floor slab 40. This construction reduces the amplitude of the vibration mode to occur in the floor slab 40 when subjected to impact, as compared with the case that the projecting part 41 is not provided. So, the floor structure 1 improves its performance to interrupt floor impact sounds.

Description

  The present invention relates to a floor structure, and more particularly to a floor structure suitable for use in reducing floor impact sound, and particularly in reducing heavy floor impact sound.

  The floor impact sound is a sound that is a problem in an apartment house such as a condominium, and is a sound caused by a person walking, jumping, dragging furniture, dropping tableware, or the like. The floor impact sound generates vibrations with a wide frequency component depending on the hardness and the length of time for which the impact is applied. It is a sound.

  This floor impact sound is classified into a light floor impact sound and a heavy floor impact sound. The light floor impact sound is a sound generated by dragging furniture, a falling object, etc., and the heavy floor impact sound is a sound generated by a person walking, jumping, jumping, or the like.

  In order to block the sound as described above, various methods for improving the floor blocking performance, for example, by changing the cross section of the floor slab to a variable cross section combining a horizontal surface, an inclined surface and a step, the floor blocking performance is increased. A method has been proposed (see, for example, Patent Documents 1 and 2). In the floor slab having the modified cross section described in Patent Documents 1 and 2, the floor weight and the floor rigidity can be regularly adjusted by adopting the modified cross section, and the floor blocking performance is improved. .

JP 2006-328951 A JP 2006-009249 A

  However, depending on the shape of the slab when viewed in plan, there is a problem in that the performance of blocking floor impact sound is low, and even when the thickness of the slab is increased, it is difficult to improve the blocking performance. Specifically, in the case of a rectangular slab whose side is divided by a beam in a range of 4 m to 8 m, particularly in a range of 5 m to 6 m, the floor impact sound blocking performance is lower than that of other shapes. The inventors have found that even if the thickness of the slab is increased, the blocking performance is hardly improved.

  In addition, rectangular slabs with a side of 5m to 6m divided by beams are used in many buildings. There was a problem that it was not done enough.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a floor structure capable of improving the insulation performance against floor impact sound regardless of the shape and size of the slab. To do.

In order to achieve the above object, the present invention provides the following means.
In the floor structure according to the first aspect of the present invention, one of the two sides facing the first beam that connects a plurality of columns arranged in a row in the row direction is fixed and intersects the row direction ( More preferably, the floor slab has a plate-like floor slab that extends in the direction orthogonal to each other and is fixed to the other two sides facing each other by a second beam that connects between columns belonging to different rows. The surface surrounded by the beam and the second beam protrudes including a belly region when the vibration mode is formed on the floor slab, and a protrusion extending in a bowl shape toward the periphery of the surface surrounded by the belly region Is provided.

  The protruding portion is a range of one section obtained by dividing the second beam facing each other into eight equal parts on both sides in the column direction around the antinode that is the point where the amplitude is maximum between adjacent nodes in the vibration mode, and , Including an abdominal region that is a range of one section obtained by dividing the space between the first beams facing each other on both sides in the direction intersecting the row direction with the above-mentioned antinode as the center, and the above-mentioned enclosed addition from the abdominal region More preferably, it projects like a bowl toward the periphery of the slab surface. Further, the protrusion includes an antinode that is a point where the amplitude is maximum between adjacent nodes in the vibration mode, and protrudes in a bowl shape from the antinode toward the periphery of the enclosed additional slab surface, Further preferred.

  The floor slab in the floor structure of the present invention has a long side extending in the column direction in which the columns are arranged (the direction in which the first beam extends), and a short side extending in the direction intersecting the column direction (in the direction in which the second beam extends). Are formed in a rectangular shape.

  By providing the protrusions on the floor slab in the shape as described above, the vibration mode pattern formed on the floor slab when an impact is applied to the floor slab compared to when no protrusion is provided As the value changes, the amplitude decreases, or the amplitude is suppressed even if the vibration mode pattern is the same. Since the vibration mode formed in the floor slab, that is, the amplitude of vibration is reduced, the performance of blocking the floor impact sound in the floor structure of the present invention can be improved.

  The position where the protruding portion is provided intersects the column direction centering on the antinode, on the both sides in the column direction, a range of one section divided between the opposing second beams, and the above antinode. The vibration amplitude in the floor slab can be reduced by including at least a belly region which is a range of one section obtained by dividing the space between the first beams facing each other on both sides in the direction. When the protruding portion does not include this abdominal region, the effect of reducing the vibration amplitude in the floor slab is hardly exhibited. For example, the effect of reducing the amplitude of vibration is 0.5 dB or less.

  In particular, the distance between columns in the above-described row direction in which the first beam extends and the above-described row direction in which the second beam extends is in the range of 4 to 8 m, more preferably 5 m. Between the floor structure of the present invention and other floor structures in the range of 6 m to 6 m (the range in which the barrier performance in the floor structure is low and the barrier performance is difficult to improve even if the floor slab thickness is increased) There is a big difference in the shut-off performance between the two.

  In a state where no protrusion is provided on the floor slab, the antinode region of the vibration mode formed on the floor slab includes an intersection where a pair of four dividing lines described below and an equal dividing line intersect. In other words, the intersection is the position having the largest amplitude between adjacent nodes in the vibration mode, as will be described later. Therefore, the amplitude of the vibration mode can be suppressed by projecting the projecting portion from the abdominal region including the intersection to the periphery.

  The pair of four dividing lines are two four dividing lines adjacent to the first beam, excluding the central four dividing line among the three four dividing lines that equally divide the space between the opposing first beams. is there. Further, the arrangement position of the pair of four-partition lines is such that the amplitude between nodes in the vibration mode formed between the opposing first beams (vibration mode viewed in a cross section cut by a plane orthogonal to the first beam) is the highest. It corresponds to the belly, which is a large position. The equal dividing line is a line that equally divides between the opposing second beams. Furthermore, the position of the equal dividing line has the largest amplitude between nodes in the vibration mode formed between the opposing second beams (vibration mode viewed in a cross section cut by a plane orthogonal to the second beam). The position is consistent with the belly.

  By providing the protruding portion so as to extend in parallel with the first beam or the second beam, the opposing second beam or the first that affects the vibration mode formed on the floor slab, particularly the magnitude of the heavy floor impact sound. An effect of suppressing the amplitude can be obtained with respect to the vibration mode formed between the beams.

  The protrusion and the first beam or the second beam may be separated by a separation groove. Even if the projecting portion is separated from the first beam or the second beam, the projecting portion serves to suppress the amplitude of the vibration mode in the floor slab, but does not serve as a beam that supports the floor slab. Therefore, compared with the case where it also serves as a beam, the strength required for the protruding portion is reduced, and the cross-sectional area required for the protruding portion is reduced. That is, the protrusion height and the width of the protrusion can be reduced from the floor slab in the protrusion to reduce the size of the protrusion.

  When the protrusion is connected to the first beam or the second beam, the protrusion can serve as a beam that supports the floor slab. In this case, the protrusion is required to have a strength sufficient to serve as a beam. For example, as compared with the case where the protruding portion and the first beam or the second beam are separated from each other, it is required that the cross-sectional area of the protruding portion be increased, specifically, to have strength against a bending moment.

  According to the floor structure of the present invention, the surface surrounded by the first beam and the second beam in the floor slab protrudes from the abdominal region when the vibration mode is formed in the floor slab, and the surface surrounded by the abdominal region. Providing protrusions extending in a bowl shape toward the periphery can change the vibration mode pattern formed on the floor slab and reduce the amplitude, or suppress the amplitude even if the vibration mode pattern is the same. Regardless of the shape and size of the slab, there is an effect that it is possible to improve the blocking performance against the floor impact sound.

It is a mimetic diagram explaining the composition of the floor structure concerning a 1st embodiment of the present invention. It is an AA 'cross section view explaining the composition of the floor structure of FIG. It is a BB 'cross section view explaining the structure of the floor structure of FIG. It is a schematic diagram explaining the position where the protrusion part of FIG. 1 is arrange | positioned. It is a schematic diagram explaining the numerical analysis model used when calculating | requiring the interruption | blocking performance in a heavy floor impact sound. It is a graph explaining the relationship between the frequency and impedance level in the floor structure of this embodiment. It is a reference figure explaining the vibration state of a floor slab in the floor structure which has only a floor slab, the 1st beam, and the 2nd beam. It is a figure of the analysis result explaining the vibration state of the floor slab in the floor structure of a 1st embodiment. It is sectional drawing explaining the other Example which changed the position which provides the protrusion part of FIG. It is a schematic diagram explaining the other Example in the floor structure of FIG. It is a schematic diagram explaining the structure of the floor structure which concerns on the modification of the 1st Embodiment of this invention. FIG. 12 is a CC ′ cross-sectional view for explaining the configuration of the floor structure of FIG. 11. It is a schematic diagram explaining the structure of the floor structure which concerns on the 2nd Embodiment of this invention. It is a graph explaining the relationship between the frequency and impedance level in the floor structure of this embodiment. It is a figure of the analysis result explaining the vibration state of the floor slab in the floor structure of this embodiment.

[First Embodiment]
Hereinafter, the floor structure according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram illustrating the configuration of the floor structure according to the present embodiment, FIG. 2 is a cross-sectional view taken along the line AA ′ illustrating the configuration of the floor structure of FIG. 1, and FIG. It is a BB 'cross-sectional view explaining the structure of 1 floor structure.

  In the present embodiment, the floor structure 1 of the present invention is arranged in a range of 4 to 8 m, more preferably 5 to 6 m in both span direction (row direction) and carry direction (direction intersecting the row direction). A description will be given by applying to an RC structure which is supported by the arranged beams.

  As described above, when the support interval of the floor structure 1 is 5 m to 6 m, the floor structure 1 of the present invention may be applied, or when the support interval of the floor structure 1 is other than 5 m to 6 m. Alternatively, the floor structure 1 of the present invention may be applied. When the support interval of the floor structure 1 is 5 to 6 m, the floor structure 1 has the worst shielding performance against floor impact sound such as heavy floor impact sound. The improvement is most noticeable. Even if the support interval of the floor structure 1 is other than 5 m to 6 m, it is possible to improve the blocking performance, which is an effect of the application of the floor structure 1 of the present invention.

  As shown in FIGS. 1 to 3, the floor structure 1 has a plurality of columns extending in the vertical direction (perpendicular to the paper surface of FIG. 1) and arranged side by side in the span direction (horizontal direction of FIG. 1). 10, a first beam 20 extending in the span direction and connecting between the columns 10, a second beam 30 extending in the traveling direction (vertical direction in FIG. 1) and connecting between the columns 10, A floor slab 40 which is a floor slab fixed to the second beam 30 is mainly provided.

  The column 10 supports the first beam 20, the second beam 30, and the floor slab 40. In the present embodiment, the column 10 is described as applied to a rectangular column having a rectangular cross section. The pillars 10 are arranged on the two straight lines extending in the span direction so as to be arranged at equal intervals with a predetermined interval within a range of 5 m to 6 m. The two straight lines in which the plurality of pillars 10 are arranged are arranged in parallel at a predetermined interval within a range of 5 m to 6 m in the carry direction.

  The first beam 20 and the second beam 30 support the floor slab 40 and will be described by applying to a shape whose cross section is necessary to support the floor slab 40, for example, a rectangular shape. In addition, the cross section of the first beam 20 and the second beam 30 is preferably formed in a rectangular shape as described above in consideration of the workability when the floor structure 1 is constructed. Various shapes can also be applied.

  The first beam 20 extends in the span direction and in the horizontal direction, and its end is fixed to the column 10 disposed adjacent to the span direction. A floor slab 40 is fixed to a side surface of one first beam 20 facing the other first beam 20.

  The second beam 30 is arranged extending in the carry direction and in the horizontal direction, and its end is fixed to the column 10 arranged adjacent to the carry direction. The second beam 30 supports the floor slab 40, and the space between the second beam 30 and the floor slab 40 is between the beam and the floor in the steel structure (hereinafter referred to as "S structure"). The structure is equivalent to the structure.

  The floor slab 40 is a plate member disposed in a rectangular space formed between the pillar 10 and the first beam 20. The floor slab 40 is provided with a protrusion 41 that enhances the performance of blocking floor impact sound, particularly heavy floor impact sound, in the floor structure 1.

FIG. 4 is a schematic diagram for explaining a position where the protruding portion of FIG. 1 is arranged.
The protrusion 41 protrudes downward from the lower surface of the floor slab 40 and is arranged extending in a bowl shape. The protrusion 41 passes through the antinode region AN in the vibration mode formed in the floor slab 40 surrounded by the first beam 20 and the second beam 30, and is arranged to extend in parallel with the second beam 30. . More preferably, it includes an antinode which is a point where the amplitude is maximum between adjacent nodes in the vibration mode, and is arranged extending in parallel with the second beam 30. The protruding portion 41 extends to the first beam 20, and an end portion thereof is connected to the first beam 20.

  Here, the abdominal region AN is formed in the floor slab 40 surrounded by the first beam 20 and the second beam 30 obtained by numerical calculation described later in a state where the protrusion 41 is not provided on the floor slab 40. Centered on the antinode in the vibration mode, the range of one section obtained by dividing the space between the opposing second beams 30 into 8 equal parts on both sides in the span direction, and between the opposing first beams 20 on both sides in the carry direction Is a range of one section obtained by dividing the area into eight.

  The vibration mode formed in the floor slab 40 surrounded by the first beam 20 and the second beam 30 is fixed to the second beam 30 in a cross-sectional view cut along a plane perpendicular to the floor slab 40 and the beam direction. The vibration mode in which two portions of the portion are nodes and one central portion is an antinode, and in a sectional view cut along a plane perpendicular to the floor slab 40 and the span direction, the fixing portion to the first beam 20 and This is a vibration mode with the three central places as nodes and the two places in between.

  The vibration mode formed in the floor slab 40 surrounded by the first beam 20 and the second beam 30 is not limited to the vibration mode described above, and may be another vibration mode. Specifically, in a cross-sectional view cut along a plane perpendicular to the floor slab 40 and the direction of girder, two portions of the fixing portion to the second beam 30 are nodes, and one central portion is a belly 1 The secondary vibration mode or the tertiary vibration mode may be used without being limited to the secondary vibration mode. In the cross-sectional view cut along the plane perpendicular to the span slab 40 and the span direction, it is limited to the secondary vibration mode in which the fixed portion with the first beam 20 and the central three places are nodes, and the two places in between are nodes. The primary vibration mode, the tertiary vibration mode, or the like may be used without being performed.

  More preferably, among the equal dividing line DL that equally divides the pair of first beams 20 and the three four dividing lines QL that equally divide the pair of second beams 30 into four, the central four dividing lines A range of one section obtained by dividing the opposing second beams 30 into eight equal parts on both sides in the span direction around the intersection CP with the quadrant QL adjacent to the second beams 30 excluding QL; and It passes through a range of one section (hereinafter referred to as “intersection region”) divided into eight sections between the opposing first beams 20 on both sides in the direction of the beam, and is arranged so as to extend on the equal dividing line DL. It is desirable. An intersection area between the equal dividing line DL and the four dividing line QL adjacent to the second beam 30 is an area that is included in or coincides with the above-described antinode region AN.

  In the floor structure 1 configured as described above, the weight of the floor slab 40 is supported by the column 10 mainly through the first beam 20 and the second beam 30. In addition, since both ends are connected to the second beam 30, the weight of the floor slab 40 is further supported by the column 10 via the protrusion 41 and the second beam 30. That is, since the protrusion 41 also serves to support the floor slab 40, it has a cross-sectional area that can withstand the support of the floor slab 40. For example, as will be described later, compared to the case where the protrusion does not have a role of supporting the floor slab 40 (under the assumption that the dimension in the direction parallel to the lower surface of the floor slab 40 is the same), in the protrusion 41, The distance from the lower surface of the floor slab 40 to the lower surface of the protruding portion 41 is formed large.

  Next, the improvement of the blocking performance of floor impact sound, particularly heavy floor impact sound, in the floor structure 1 having the above-described configuration will be described. Specifically, the improvement of the floor impact sound blocking performance in the floor structure 1 of the present embodiment will be described based on numerical analysis using a finite element method (FEM). Here, the impedance of the floor slab is analyzed using the finite element method, and the sound radiated from the floor slab is calculated using the same method as the “impedance method (Architectural Institute of Japan)”.

FIG. 5 is a schematic diagram for explaining a numerical analysis model used when obtaining a blocking performance in heavy floor impact sound.
The model used for the numerical analysis will be described with reference to FIG. The numerical analysis model shown in FIG. 5 is a model used for analysis of a conventional floor structure having a floor slab 40, a first beam 20, and a second beam 30. In this numerical analysis model, five floor slabs 40 surrounded by the first beam 20 and the second beam 30 are arranged in series, and a plurality of excitation points VP are provided to the floor slab 40 arranged at the center thereof. (For example, 49 excitation points VP) are uniformly distributed. Moreover, the numerical analysis model similar to the numerical analysis model shown in FIG. 5 is used also for the numerical analysis with respect to the floor structure 1 of this embodiment. In the numerical analysis with respect to the floor structure 1 of the present embodiment, the protruding portion 41 is provided on the floor slab 40.

  The impedance of the floor slab 40 is calculated for each excitation point VP by calculating an impedance obtained by averaging the transmission impedances to all the calculation nodes provided in the floor slab 40, and further obtained for each excitation point VP. The impedance is calculated by averaging all the excitation points VP.

  FIG. 6 is a graph for explaining the relationship between the frequency and the impedance level in the floor structure 1 of the present embodiment. The solid line in FIG. 6 shows the change in the impedance level (dB) in the floor structure 1 of the present embodiment, and the broken line shows the change in the impedance level (dB) in the conventional floor structure. Note that the larger the impedance level (dB), the higher the performance of blocking heavy floor impact sound. Furthermore, the 63 Hz band shown in FIG. 6 is likely to be a decision frequency (a frequency having a decisive influence) when evaluating the cutoff performance in heavy floor impact sound.

  As shown in FIG. 6, the impedance level in the floor structure 1 of the present embodiment tends to be higher than the impedance level in the conventional floor structure in a range where the frequency (Hz) is lower than about 100 Hz. Similarly, in the 63 Hz band shown in FIG. 6, the floor structure 1 of the present embodiment also shows a tendency that the impedance level is higher than the conventional floor structure. That is, it is shown that the floor structure 1 of the present embodiment has higher performance for blocking heavy floor impact sound than the conventional floor structure.

  FIG. 7 is a reference diagram illustrating a vibration state of the floor slab 40 in the floor structure having only the floor slab 40, the first beam 20, and the second beam 30. FIG. FIG. 8 is an analysis result diagram illustrating the vibration state of the floor slab 40 in the floor structure of the present embodiment.

  Next, the vibration state (see FIG. 8) of the floor slab 40 in the floor structure 1 of the present embodiment and the vibration of the floor slab 40 in the conventional floor structure having the floor slab 40, the first beam 20, and the second beam 30. The state (see FIG. 7) is compared. Curves indicated by thin lines in FIGS. 7 and 8 are curves representing the magnitude of amplitude in the floor slab 40.

  In the floor slab 40 in the conventional floor structure, as shown in FIG. 7, in the region surrounded by the first beam 20 and the second beam 30, two antinode regions (regions surrounded by a closed curve consisting of thin lines) AN are formed. The vibration mode to be formed is formed. The two abdominal regions AN are arranged in the direction of the carry in the floor slab 40. The heavy floor impact sound at this time is set as a reference (0 dB).

  In the floor structure 1 of the present embodiment, as shown in FIG. 8, the aspect of vibration in the floor slab 40 changes greatly. That is, a vibration mode that forms one antinode region AN in the region surrounded by the first beam 20, the second beam 30, and the protruding portion 41 is formed in the floor slab 40. As in the case described above, when viewed in the region surrounded by the first beam 20 and the second beam 30, the floor slab 40 forms a vibration mode that forms two antinode regions AN side by side in the span direction. Furthermore, the amplitude in the abdominal area AN in the floor structure 1 of the present embodiment is smaller than the amplitude in the abdominal area AN in the conventional floor structure. Therefore, the heavy floor impact sound in the floor structure 1 of the present embodiment is smaller than that of the conventional floor structure (−12 dB).

  According to said structure, compared with the case where the protrusion part 41 is not provided in the floor slab 40, when an impact is applied to the floor slab 40 by providing the protrusion part 41 in the floor slab 40, the floor While changing the vibration mode pattern in the slab 40, the amplitude of the vibration mode (especially the amplitude in the abdominal region AN) can be reduced. Therefore, it is possible to improve the blocking performance against floor impact sound, particularly heavy floor impact sound, in the floor structure 1 of the present embodiment.

  In particular, the distance between the pillars 10 in the span direction in which the first beam 20 extends and in the girder direction in which the second beam 30 extends is in the range of 4 m to 8 m (for example, 4 m × 4 m to 7 m × 8 m). In the range of 5 m to 6 m, the barrier performance in the floor structure is low even when the interval between the pillars 10 is lower than that in other ranges, and the thickness of the floor slab 40 is increased. The blocking performance is difficult to improve. Therefore, when the space | interval of pillars 10 is in this range, a big difference arises in interruption | blocking performance between the floor structure 1 of this embodiment, and other floor structures.

  Furthermore, by providing the protrusion 41 so as to extend in parallel with the first beam 20, the vibration mode in the floor slab 40, in particular, the magnitude of the heavy floor impact sound is affected. The effect of suppressing the amplitude of the vibration mode in the floor slab 40 surrounded by the two beams 30 can be obtained.

FIG. 9 is a cross-sectional view for explaining another embodiment in which the position where the protrusion 41 of FIG. 2 is provided is changed.
In the above-described embodiment, the projecting portion 41 is described as applied to an example in which the projecting portion 41 projects downward from the lower surface of the floor slab 40. However, as illustrated in FIG. You may make it protrude toward upper direction.

  By doing in this way, compared with the case where the protrusion part 41 is protruded below from the lower surface of the floor slab 40, it becomes easy to form the protrusion part 41A. That is, when forming the floor structure 1 of this embodiment which is RC structure (when placing concrete), compared with the case where the protrusion 41 is provided on the lower surface of the floor slab 40, the floor slab 40 When the protrusion 41A is provided on the upper surface, it is easy to assemble the mold and to easily put the concrete.

FIG. 10 is a schematic diagram for explaining another embodiment of the floor structure 1 of FIG.
In the above-described embodiment, the column 10 extending in the span direction has been described as being applied to an example having two (two) columns. However, as illustrated in FIG. 10, the column 10 extending in the span direction includes three columns 10. Rows (three) may be arranged in parallel.

[Modification of First Embodiment]
Next, a floor structure according to a modification of the first embodiment of the present invention will be described with reference to FIGS. The basic configuration of the floor structure of this modification is the same as that of the first embodiment, but the configuration of the protruding portion is different from that of the first embodiment. Therefore, in the present embodiment, only the configuration of the protruding portion will be described with reference to FIGS. 11 and 12, and description of other components and the like will be omitted. FIG. 11 is a schematic diagram illustrating the configuration of the floor structure of the present modification, and FIG. 12 is a CC ′ cross-sectional view illustrating the configuration of the floor structure of FIG.

  As shown in FIGS. 11 and 12, the floor slab 140 in the floor structure 101 of the present modification is provided with a protruding portion 141 that enhances the performance of blocking floor impact sound, particularly heavy floor impact sound, in the floor structure 101. .

  Similar to the projecting portion 41 of the first embodiment, the projecting portion 141 projects downward from the lower surface of the floor slab 140 and extends in a bowl shape. A separation groove 142 is provided between the protrusion 141 and the first beam 20, and the protrusion 141 and the first beam 20 are separated by the separation groove 142.

  As described above, since the protruding portion 141 is separated from the first beam 20 by the separation groove 142, the protruding portion 141 does not play a role of supporting the weight of the floor slab 140. Therefore, as compared with the protruding portion 41 of the first embodiment connected to the first beam 20, the protruding portion 141 of this modification only has a role of enhancing the barrier property of the floor impact sound, and has a smaller cross-sectional area. It is formed with. For example, the distance from the lower surface of the floor slab 140 to the lower surface of the protrusion 141 is formed small (under the assumption that the dimensions in the direction parallel to the lower surface of the floor slab 140 are the same).

  By setting it as such a structure, a cross-sectional area required for the protrusion part 141 can be made small. Even if the protruding portion 141 is separated from the first beam 20, the protruding portion 141 can serve to suppress the amplitude of the vibration mode in the floor slab 140, but does not serve as a beam that supports the floor slab 140 from below. . Therefore, compared with the case where the protrusion 41 also serves as a beam as in the first embodiment, the strength required for the protrusion 141 is reduced, and the cross-sectional area required for the protrusion 141 is reduced. As a result, as compared with the case where the projecting portion 41 is connected to the first beam 20 as in the first embodiment, the projecting height from the floor slab 140 in the projecting portion 141 is ensured while the improvement in the barrier performance of the floor impact sound is ensured. The width of the protrusion 141 (the dimension in the direction parallel to the lower surface of the floor slab 140) can be reduced to reduce the size of the protrusion 141.

[Second Embodiment]
Next, a floor structure according to a second embodiment of the present invention will be described with reference to FIGS. The basic configuration of the floor structure of the present embodiment is the same as that of the first embodiment, but the extending direction of the protruding portion is different from that of the first embodiment. Therefore, in the present embodiment, only the periphery of the protruding portion will be described using FIGS. 13 to 15, and description of other components and the like will be omitted. FIG. 13 is a schematic diagram illustrating the configuration of the floor structure according to the present embodiment.

  As shown in FIG. 13, the floor slab 240 in the floor structure 201 of the present embodiment is provided with a protrusion 241 that enhances the performance of blocking floor impact sound, particularly heavy floor impact sound, in the floor structure 201.

  The protruding portion 241 protrudes downward from the lower surface of the floor slab 240 and is arranged extending in a bowl shape. The protrusion 241 passes through the floor slab 240 surrounded by the first beam 20 and the second beam 30 including the antinode region AN in the vibration mode, and is arranged to extend in parallel with the second beam 30. More preferably, it includes an antinode which is a point where the amplitude is maximum between adjacent nodes in the vibration mode, and is arranged extending in parallel with the second beam 30. The projecting portion 241 extends to the second beam 30, and an end thereof is connected to the second beam 30.

  In the floor structure 201 having the above configuration, the weight of the floor slab 240 is supported by the column 10 mainly through the first beam 20 and the second beam 30. In addition, since both ends are connected to the first beam 20, the weight of the floor slab 240 is further supported by the column 10 via the protruding portion 241 and the first beam 20. That is, since the protrusion 241 also plays a role of supporting the floor slab 240 from below, it has a cross-sectional area that can withstand the support of the floor slab 240.

  Next, the improvement in the barrier property of floor impact sound, particularly heavy floor impact sound, in the floor structure 201 having the above-described configuration will be described. Specifically, as in the first embodiment, the improvement of the floor impact sound blocking performance in the floor structure 201 of the present embodiment will be described based on numerical analysis using the finite element method (FEM).

  FIG. 14 is a graph for explaining the relationship between the frequency and the impedance level in the floor structure 201 of the present embodiment. A solid line in FIG. 14 shows a change in impedance level (dB) in the floor structure 201 of the present embodiment, and a broken line shows a change in impedance level (dB) in the conventional floor structure.

  As shown in FIG. 14, the impedance level in the floor structure 201 of the present embodiment tends to be higher than the impedance level in the conventional floor structure over almost all frequencies (Hz) from which results are obtained. . Similarly, in the 63 Hz band shown in FIG. 14, the floor structure 201 of this embodiment has a tendency that the impedance level is higher than that of the conventional floor structure. That is, it is shown that the floor structure 201 of the present embodiment has higher performance for blocking heavy floor impact sound than the conventional floor structure.

FIG. 15 is an analysis result diagram illustrating the vibration state of the floor slab 240 in the floor structure of the present embodiment.
Next, the vibration state of the floor slab 240 (see FIG. 15) in the floor structure 201 of the present embodiment and the vibration state of the floor slab 40 in the conventional floor structure having the first beam 20 and the second beam 30 (FIG. 7). See).

  In the floor structure 201 of this embodiment, as shown in FIG. 15, vibration in the same mode (vibration mode) as the floor slab 40 in the conventional floor structure is generated. That is, in the region surrounded by the first beam 20 and the second beam 30, a vibration mode that forms two antinode regions AN is generated. The two abdominal regions AN are arranged in the direction of the carry in the floor slab 240. The difference between the floor structure 201 of the present embodiment and the conventional floor structure is the magnitude of the amplitude, and the amplitude of the floor structure 201 of the present embodiment is smaller than that of the conventional floor structure. Therefore, the heavy floor impact sound in the floor structure 201 of the present embodiment is smaller than that of the conventional floor structure (−7 dB).

  According to the above configuration, by providing the projecting portion 241 extending in parallel with the second beam 30, the opposing first beam that affects the vibration mode in the floor slab 240, particularly the magnitude of the heavy floor impact sound. 20 and the effect of suppressing the amplitude of the vibration mode in the floor slab 240 surrounded by the opposing second beam 30 can be obtained. Therefore, it is possible to improve the blocking performance against floor impact sound, particularly heavy floor impact sound, in the floor structure 201 of the present embodiment.

  DESCRIPTION OF SYMBOLS 1,101,201 ... Floor structure, 10 ... Column, 20 ... 1st beam, 30 ... 2nd beam, 40, 140, 240 ... Floor slab, 41, 41A, 141, 241 ... Projection part, 142 ... Separation groove, DL ... Equal dividing line, QL ... 4 dividing line

Claims (6)

A first beam extending between the columns arranged in a plurality of rows in the row direction and connecting the adjacent columns;
A second beam extending in a direction crossing the row direction and connecting the opposing columns;
Floor slabs fixed to the first beam and the second beam, respectively, on opposite sides;
A protrusion projecting in a bowl shape from the antinode region of the vibration mode on the surface of the floor slab surrounded by the pair of first beams and the pair of second beams toward the periphery of the enclosed floor slab;
Floor structure characterized by being provided with. The antinode region is divided into eight equal parts between the opposing second beams on both sides in the row direction, with the antinode being the point where the amplitude is maximum between adjacent nodes in the vibration mode. The range of the section, and the range of one section obtained by dividing the space between the first beams facing each other on both sides in the direction intersecting the column direction with the antinode as the center,
2. The floor structure according to claim 1, wherein the protruding portion protrudes including the abdominal region and protrudes from the abdominal region toward the periphery of the surface of the enclosed floor slab. The abdominal region includes a pair of four dividing lines adjacent to the first beam among three four dividing lines that equally divide the space between the first beams facing each other and the space between the second beams facing each other. A range of one section obtained by equally dividing the second beam between the two opposite beams on both sides in the column direction around the intersection with the equally dividing line to be divided, and intersecting the column direction around the intersection A range of one section divided between the opposing first beams on both sides in the direction of
2. The floor structure according to claim 1, wherein the protruding portion protrudes including the abdominal region and protrudes from the abdominal region toward the periphery of the surface of the enclosed floor slab. The antinode region is an antinode that is a point where the amplitude is maximum between adjacent nodes in the vibration mode, or the three quadrants that divide between the first beams facing each other into four equal parts. An intersection of a pair of four dividing lines adjacent to the first beam and an equal dividing line that equally divides the second beam facing each other;
2. The floor structure according to claim 1, wherein the protruding portion protrudes including the abdominal region and protrudes from the abdominal region toward the periphery of the surface of the enclosed floor slab.   The floor structure according to any one of claims 1 to 4, wherein the protrusion extends in parallel with the first beam or the second beam. When the protrusion extends parallel to the first beam, a separation groove is provided between the protrusion and the second beam, and the protrusion and the second beam are separated from each other.
When the protrusion extends in parallel with the second beam, the separation groove is provided between the protrusion and the first beam, and the protrusion and the second beam are separated from each other. The floor structure according to claim 5.

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