Dry type double floor structure

Abstract

To reduce an impact sound and a solid-borne sound without increasing the diameter (thickness) of a sleeper and to avoid the floor height of a floor structure in a dry double floor structure.SOLUTION: A double floor structure 100 of the present invention is a double floor structure including a slab 10 in a reinforced concrete building and a floor component provided on the slab, and the floor component includes a sleeper 1 including a set of two long structures 11,11 arranged close to each other, a plurality of joists 2 placed on a plurality of sets of sleepers, a floor member 3 laid on the joists, and a support member 5 for arranging the sleepers on the slab at intervals. The sleeper is provided with a connecting member 4 at the end in the longitudinal direction, holds a set of long structures, and connects the sleepers to each other in the longitudinal direction. The support member is attached to the tie member and installed near a side wall of a building or on a beam of the building.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a dry double floor structure in which floors are formed at intervals on the main floor of a multi-story building, and more particularly to a dry double floor structure that can reduce impact sounds and solid-borne sounds transmitted from upper floors to lower floors. [Background technology]

[0002] In dwellings that are connected to each other on two upper and lower floors of a building, for example, impact sounds (heavy floor impact sounds) caused by children jumping or objects falling on the upper floors can be transmitted as noise to the floor below, causing problems for those on the upper and lower floors. As a countermeasure against such heavy floor impact noise, for example, in the case of a reinforced concrete (RC) building, a structure in which the thickness of the structural slab is increased is known. Another known structure is a double floor structure in which support members with elastic bodies such as vibration-isolating rubber are placed on top of the structural slab to support the floor, and these support members absorb vibrations caused by floor impacts, thereby ensuring soundproofing performance.

[0003] Therefore, in order to increase the effect of reducing heavy floor impact noise, a method has been proposed in which both ends of the joists in the longitudinal direction are installed via support members that are placed near the side walls of the building, near the parts corresponding to the beams supporting the slab, and on the top surface of the slab at the parts corresponding to the beams (see, for example, Patent Documents 1 and 2). That is, the support legs of the dry double floor structure are installed on the beams of the slab structure of the building, which have high impedance.

[0004] However, in a floor structure constructed using the above method, the support leg pitch becomes longer, and the joists at the center of the support leg pitch become more flexed. To reduce this flexure, strong joists are used, but using strong materials increases the diameter (thickness) of the joists, which creates the problem of increasing the floor height of the floor structure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Registered Utility Model No. 3179267 [Patent Document 2] Japanese Patent Application Publication No. 2018-109306 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention was developed in consideration of the above-mentioned conventional circumstances, and aims to provide a technology in dry double floor structures that reduces impact noise and solid-borne noise while avoiding an increase in floor height of the floor structure without increasing the diameter (thickness) of the joists. [Means for solving the problem]

[0007] The dry double floor structure of the present invention is a double floor structure comprising a slab in a reinforced concrete building and a floor component arranged on top of the slab, and is characterized in that the floor component comprises at least joists consisting of a set of multiple long structures arranged closely together, joists placed on the joists, floor members laid on the joists, and support members that allow the joists to be arranged at intervals on the slab.

[0008] In the above-mentioned dry double floor structure, the joists may be provided with connecting members that hold the long structures in close proximity. That is, the joists may be configured to hold a plurality of long structures in close proximity as a set using connecting members.

[0009] The joists may have a length equal to the length of the elongated structure from the vicinity of the side wall of the building to the beam of the building or the length between beams of the building, and the connecting members may be provided at the longitudinal ends of the joists to hold the elongated structures close together and connect the joists together in the longitudinal direction. That is, the joists may have a structure that includes connecting members at the longitudinal ends, holds a plurality of elongated structures close together by the connecting members, and connects the elongated structures held as a set that constitutes a joist together in the longitudinal direction via the connecting members.

[0010] The connecting members may have joint surfaces that are sized to expand outward in a direction perpendicular to the length of the joists, and the joists may be connected by fastening the joint surfaces of the connecting members together so that they face each other. In other words, the connecting members may have joint surfaces that are sized to expand outward in a direction perpendicular to the length of the joists, and the joists may be connected by fastening the joint surfaces of the connecting members provided at the ends of the joists in the length direction so that they face each other.

[0011] Such a joist may be integral with the connecting member. The joists and connecting members may be made of metal. It is also desirable that the support member be attached to a connecting member and installed near the side wall of the building and / or on a beam of the building.

[0012] In the above-mentioned dry double floor structure, the joists are of a length equal to the length of the long structure from near the side wall of the building to the beam in the building or the length between beams in the building, and are provided with connecting members at the longitudinal ends that hold the long structures close together and enable the joists to be connected to each other in the longitudinal direction, and are connected by fastening together the joint surfaces of the connecting members, which are sized to expand outward perpendicular to the longitudinal direction of the joists, and the joists and connecting members are made of metal as a single unit, and the support members are attached to the connecting members and installed near the side wall of the building and / or on the beams in the building.

[0013] In addition, in each of the above-mentioned dry double floor structures, it is desirable that the joists have a bending rigidity such that when an impact load acts downward on the center part of the length, the deflection at that center part is 5 mm or less. In addition, in each of the above-mentioned dry double floor structures, it is desirable that the support members include nonlinear vibration-isolating rubber. Furthermore, in each of the above-mentioned dry double floor structures, it is desirable that the support members have a level adjustment mechanism.

[0014] In addition, in each of the above-mentioned dry double floor structures, sound-absorbing material may be installed between the slab and the floor member. Furthermore, in each of the above-mentioned dry double floor structures, the joists can be a set of two long structures. [Effects of the Invention]

[0015] According to the present invention, by forming a set of adjacent long structures into a joist, it is possible to reduce the diameter (thickness) of the joist without reducing its strength, thereby avoiding an increase in floor height of the floor structure. Also, by placing the joists at intervals on the slab using support members, the support members can absorb vibrations caused by floor impacts, ensuring soundproofing performance. Therefore, in a dry double floor structure, it is possible to provide a dry low-floor double floor that reduces impact noise and solid-borne noise while increasing the interior space without increasing the diameter of the joists. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a partial plan view showing a main part of a dry double floor structure according to an embodiment of the present invention. [Figure 2] 1 is a partially enlarged schematic cross-sectional view showing a main part of a dry double floor structure according to one embodiment of the present invention. FIG. [Figure 3] 2 is a partially enlarged plan view of part A surrounded by a dashed line in FIG. 1. FIG. [Figure 4] 3 is a partially enlarged schematic cross-sectional view of part B surrounded by a dashed line in FIG. 2. FIG. [Figure 5] FIG. 4 is a cross-sectional view taken along line II shown in FIG. [Figure 6] FIG. 5 is a cross-sectional view taken along line II-II shown in FIG. [Figure 7] FIG. 2 is a side view showing a support member used in a dry double floor structure according to one embodiment of the present invention. [Figure 8] FIG. 10 is a diagram showing the relationship between load and deflection. [Figure 9] 1A and 1B are schematic cross-sectional views illustrating the floor height of a dry double floor structure according to one embodiment of the present invention, showing (A) a schematic cross-sectional view as viewed from a direction along the length of the joists, and (B) a schematic cross-sectional view as viewed from a direction perpendicular to the length of the joists. [Figure 10] (A) is a schematic cross-sectional view of the floor height of a conventional dry double floor structure, as viewed from the direction along the length of the joists, and (B) is a schematic cross-sectional view of the floor height of a conventional dry double floor structure, as viewed from the direction perpendicular to the length of the joists. DETAILED DESCRIPTION OF THE INVENTION

[0017] Below, as an example of an embodiment of the double floor structure according to the present invention, we will explain, with reference to the drawings, the case where a vibration-proof dry low-floor double floor structure is applied to the structural floor of a reinforced concrete building such as a condominium, apartment, or other collective housing complex, a school, a government office, or a facility.

[0018] The embodiments described below are preferred examples of the present invention and are therefore subject to various technical limitations. However, the scope of the present invention is not limited to these embodiments unless otherwise specified in the following description.

[0019] As shown in FIGS. 1 and 2, the double floor structure in this embodiment includes a slab 10 in a reinforced concrete building and a floor component provided on top of this slab 10. The slab 10 refers to a floor structure provided between the upper and lower floors in a multi-story building. The slab 10 may also include a so-called foundation slab, which is poured at the top of the foundation when there is no lower floor.

[0020] The floor construction section in this embodiment includes joists 1, floor joists 2, floor members 3, connecting members 4, and support members 5. The joist 1 is a member that forms a set of multiple closely arranged elongated structures 11. In other words, the joist 1 is formed to have great strength by combining multiple elongated structures 11, and is provided with connecting members 4 that hold the multiple elongated structures 11 in close proximity. In this way, by combining multiple long structures 11 to form a joist 1, the diameter (thickness) of the joist 1 can be reduced without reducing its strength, and the floor height can be lowered to make the interior space larger.

[0021] The long structures 11 used for the joists 1 can be, for example, square hollow pipes (square steel pipes with a hollow portion) made of metal such as iron, copper, stainless steel, or aluminum, but there is no particular limitation on the material. There is also no particular limitation on the number of long structures 11 to be combined. In FIG. 1, the joists 1 are shown as a set of two long structures 11, 11, and a plurality of such sets are arranged on a slab 10.

[0022] The joists 2 are members placed on a plurality of sets of joists 1, and are arranged in a direction perpendicular to the joists 1. In other words, a plurality of joists 2 are arranged between the opposing side walls 20, 20 of the building, erected on the joists 1. The material of the floor joists 2 is not particularly limited, and may be, for example, wood (LVL), synthetic resin, metal, or the like.

[0023] The floor member 3 is a member that forms a floor surface laid on the joists 2, and can be composed of, for example, a backsplash board 31 laid on the joists 2 and a finishing material 32 such as flooring laid on this backsplash board 31. The scrap board 31 serves as a base material for, for example, plywood or hard gypsum board. The finishing material 32 can be, for example, a wood-based flooring material such as flooring, a fiber-based flooring material such as carpet, or a synthetic resin-based flooring material such as vinyl chloride resin. The floor member 3 may include a floor heating panel.

[0024] In addition, a flexible expansion joint material 8 such as expansion rubber is arranged at the end of the finishing material 32 to seal the gap between it and the side wall 20, and a baseboard 9 is attached to the side wall 20 via the expansion rubber 8.

[0025] In this embodiment, the long structure 11 has a length, for example, from the vicinity of the side wall 20 of the building to the beam 30, or the length between the beams 30 of the building. Therefore, the joist 1 is also configured by combining a plurality (two) of long structures 11 each having a length from the vicinity of the side wall 20 of the building to the beam 30, or the length between the beams 30.

[0026] The joists 1 are connected to each other in the longitudinal direction via connecting members 4 attached to each of the longitudinal ends. The connecting members 4 are provided at the longitudinal ends of the joists 1, and hold multiple (two) elongated structures 11 close together as a set, while also enabling the joists 1 to be connected to each other in the longitudinal direction.

[0027] The connecting member 4 may include a joining surface 41, a support member mounting portion 42, and a connecting hole 43, as shown in FIGS. The joint surface 41 is a planar portion that is provided to cover the longitudinal end of the joist 1, and in this embodiment, it completely covers the ends of the two elongated structures 11, 11 and has an area that extends outward perpendicular to the longitudinal direction of the joist 1.

[0028] The support member mounting portion 42 is a connecting portion provided so as to bridge between two adjacent elongated structures 11, 11, and has a support member mounting hole 42a that enables the mounting of the support member 5. A support bolt 52 of the support member 5, which will be described later, is mounted in this support member mounting hole 42a. The connecting holes 43 are portions that penetrate from one side of the joining surface 41 to the other side, and are provided in multiple locations in an area that expands outward on the joining surface 41, allowing for tightening with the fastening member 6.

[0029] In Figures 3 to 6, the connecting member 4 is shown as having a vertical joint surface 41 that is approximately rectangular and long horizontally, with areas that extend outward to the left and right at the longitudinal ends of the joist 1, an inverted L-shaped support member mounting portion 42 that is connected to the joint surface 41 and has a horizontal surface that is joined to the two elongated structures 11, 11, and a plurality of connecting holes 43...43 provided in the area that expands outward on the joint surface 41.

[0030] Therefore, the joists 1 can be connected in the length direction by placing the joint surfaces 41 of the connecting members 4 facing each other and using fastening members 6 inserted into the connecting holes 43. The fastening member 6 can be, for example, a combination of a bolt 61 and a nut 62. In this embodiment, the bolt 61 is inserted into the connecting hole 43, and then the nut 62 is screwed onto the bolt 61, thereby connecting the joists 1 together in the longitudinal direction.

[0031] In this way, by attaching connecting members 4 to the longitudinal ends of the joists 1 so that they can be connected to each other, the joists 1 can be designed (manufactured) to a short length so as not to cause any problems when storing or transporting them, and by connecting the joists 1 appropriately at the construction site, they can be adjusted to the desired length.

[0032] Furthermore, the connecting members 4, like the joists 1 (long structures 11), can be formed from, for example, metal and configured integrally with the joists 1. In other words, the joists 1 and the connecting members 4 can be joined and integrated together by, for example, welding. In this way, by forming the connecting member 4 from metal and directly connecting it without painting the joint surface 41, the joists 1 can be firmly joined together with a metal-to-metal feel.

[0033] The support members 5 are members that enable the joists 1 to be arranged on the slab 10 at predetermined intervals. As shown in FIG. 7, the support member 5 includes an elastic base 51, a support bolt (support leg) 52 erected at the center of the upper surface of the elastic base 51, a level adjustment nut 53 attached to the support bolt 52, and a support plate 54 attached via the level adjustment nut 53 so that the height can be adjusted freely. In this embodiment, the support member 5 is attached to the support member attachment portion 42 of the connecting member 4 attached to the end of the joist 1.

[0034] In this support member 5, it is desirable to provide an elastic body such as non-linear vibration-isolating rubber as the base 51 at the lower end of the support bolt 52. In other words, by providing an elastic body such as non-linear vibration-isolating rubber as the base 51, the steel joists 1 can be installed on the slab 10 via the elastic body, and vibrations caused by floor impact can be absorbed by the support bolt 52 and the elastic base 51, ensuring soundproofing performance. In addition, the base (elastic body) 51 of the support member 5 can avoid impacts at the portion where it comes into contact with the subfloor ground such as concrete.

[0035] Here, "nonlinear vibration-isolating rubber" refers to vibration-isolating rubber in which the load and the amount of deflection caused by the load have a nonlinear relationship. In this embodiment, as shown in Figure 8, vibration-isolating rubber is used in which the greater the load, the smaller the relative amount of deflection.

[0036] By providing the support member 5 with a base 51 made of nonlinear vibration-isolating rubber (hereinafter sometimes referred to as "elastic body"), even if the load (number of people) on the floor member (flooring) 3 fluctuates, the pressure-receiving area of ​​the base (nonlinear vibration-isolating rubber) 51 changes, reducing impact noise and solid-state noise over a wide range at an almost constant natural frequency, thereby achieving a vibration-damping effect.

[0037] In other words, the natural frequency of nonlinear vibration-damping rubber is designed to provide vibration-damping effects above the lower limit of the human audible range, 20 Hz, so vibration-damping performance can be ensured by, for example, setting the natural frequency of the elastic body to 14 Hz (= f0 / √2) or less. The support member 5 may also be provided with a base 51 having a low natural frequency made by stacking several nonlinear vibration-isolating rubbers.

[0038] Furthermore, it is desirable that the joists 1 have a bending rigidity such that when an impact load acts downward on the center portion in the longitudinal direction, the deflection at the center portion is 5 mm or less. In other words, the joists 1 are designed to withstand a load equivalent to an impact load of, for example, 70 kg / m 2Use materials that will have a floor surface natural frequency and an elastic body natural frequency that are √2 or more times larger than the floor surface natural frequency when a load of the following magnitude acts downward during actual use.

[0039] This involves selecting joists 1 with a bending rigidity that satisfies the natural frequency of 20 Hz or more when the floor surface is unloaded. In other words, when calculating the amount of deflection that makes the natural frequency of the floor surface and the natural frequency of the elastic body √2 times or more, it is necessary to use members with a bending rigidity that makes the deflection at the center of the joists 1, which combine multiple long structures 11, 5 mm or less. In this way, by using components whose natural frequency of the floor surface and the natural frequency of the elastic body are at least √2 times, the vibration transmissibility becomes 1 or less, ensuring vibration-damping performance.

[0040] In addition, the support member 5 is capable of freely adjusting the height of the support plate 54 according to the usage conditions by rotating the level adjustment nut 53 which is screwed onto the threaded portion formed on the support bolt 52. In this way, by using a support member 5 with a level adjustment mechanism, unevenness in the slab 10 can be easily adjusted to level the floor member 3, creating a double floor structure that can easily make the floor surface level.

[0041] Therefore, in this embodiment, the joists 1 are supported against the subfloor surface (slab 10) by support members 5, and leveling can be easily performed by adjusting the height using a spirit level.

[0042] In this embodiment, the support members 5 are installed near the side walls 20 or on the beams 30. That is, the joists 1, whose length is from near the side wall 20 of the building to the beam 30 or between the beams 30, are connected using connecting members 4, and the connection of the joists 1 is performed on the strong beams 30. Therefore, the joists 1 are arranged at intervals on the slab 10 via support members 5 installed on the beams 30.

[0043] As a result, even in buildings with large floor areas, the connected joists 1 can be stably supported on the strong beams 30. In addition, impact sounds and solid-borne sounds generated in the floor members 3 can be transmitted to the beams 30 via the support members 5 and slabs 10, thereby reducing and dispersing them.

[0044] In this embodiment, the floor structure is such that sound absorbing material 7 is installed in the hollow space between slab 10 and floor member 3. The sound-absorbing material 7 is a material that attenuates the vibration of sound waves transmitted through the air, and may be, for example, a porous fibrous material. Specifically, building materials such as glass wool, which is also used as a heat insulating material, may be used as the sound-absorbing material 7.

[0045] By providing such sound absorbing material 7, air vibrations generated by floor members 3, joists 1, etc. can be absorbed, and a floor structure can be achieved that exhibits vibration damping, heat insulation, and sound absorption effects. In addition, in the hollow space between the slab 10 and the floor member 3, electrical communication cables, equipment piping, etc. can be arranged as appropriate.

[0046] The floor structure in this embodiment can be configured, for example, as follows. First, two long structures 11, each measuring the length from near the side wall 20 of the building to the beam 30 or the length between the beams 30, are placed close to each other in parallel, and connecting members 4 are attached to each end of the structures in the longitudinal direction, for example by welding, to prepare a joist 1 that holds the two long structures 11, 11 as a set.

[0047] Next, at the construction site, joists 1 are placed on the slab 10, and support members 5 are placed on the slab 10 at the part corresponding to the upper part of the beam 30. After that, the support members 5 are attached to the connecting members 4 attached to the ends of the joists 1, and the support members 5 are installed so as to be positioned above the beams 30.

[0048] Furthermore, after arranging the joists 1 adjacent to each other in the longitudinal direction so that the joint surfaces 41 of the connecting members 4 face each other, the opposing joint surfaces 41 are connected to each other using fastening parts 6 (bolts 61, nuts 62) to obtain the joists 1 of the desired length. These operations are then repeated so that multiple joists 1 are arranged in parallel at predetermined intervals between the opposing side walls 20.

[0049] Then, multiple joists 2·2 are placed on top of the joists 1 in a direction perpendicular to the longitudinal direction of the joists 1, and then floor members 3 (waste boards 31 and finishing materials 32) are laid on top of the joists 2, thereby completing the dry double floor in this embodiment. In this embodiment, before laying the floor members 3, sound absorbing material 7 such as glass wool is placed in the hollow space between the slab 10 and the floor members 3 to provide a sound insulating floor.

[0050] In the dry double floor structure configured as described above, when the support member 5 is installed near the side wall 20 or not on the beam 30, the floor impact sound level reduction performance grades measured based on JIS A1440-1 (method using standard light impact source) and JIS A1440-2 (method using standard heavy impact source) are ΔLL(II)-5 and ΔLH(II)-3, respectively.

[0051] This floor impact sound level reduction performance grade is based on the condition that the support member 5 is not installed near the side wall 20 or on the beam 30, but if the support member 5 is installed near the side wall 20 or on the beam 30, it is expected that the performance will be further improved and the impact sound and solid sound transmitted from the upper floor to the lower floor will be reduced.

[0052] Also, for example, in the floor structure of this embodiment using a pair of joists 1 made up of two long structures 11, 11 as shown in Figure 9, if the support members are installed at intervals of 3.2 m, the floor height T1 will be 200 mm. In contrast, as shown in FIG. 10, in a conventional floor structure using H-shaped steel beams 101, if support members are installed at 3.2 m intervals, the floor height T2 will be 280 mm.

[0053] Therefore, the floor structure in this embodiment can be installed 80 mm lower than conventional floor structures, so even if the support leg pitch for installing the support members becomes longer, the diameter (thickness) of the joists does not need to be increased, and a floor structure that would result in a higher floor height can be avoided, thereby making the interior space larger.

[0054] In the above-described embodiment, the joists 1 and the connecting members 4 are described as being made of metal and assembled together as an integrated unit, but the present invention is not limited to this. Therefore, the joists 1 and the connecting members 4 may also be made of wood or synthetic resin such as carbon fiber reinforced resin. Furthermore, the joists 1 and the connecting members 4 may be made of different materials and combined together, for example, the joists 1 may be made of wood and the connecting members 4 may be made of metal, and the connecting members 4 may be attached to the joists 1 with screws to form an integrated unit. [Industrial Applicability]

[0055] The present invention can be widely used in buildings with a dry double floor structure that expands the interior space, such as apartment complexes, schools, government offices, and other multi-story buildings. The present invention can also be applied to detached houses. [Explanation of symbols]

[0056] 1. Main pier 2 joists 3 Flooring 4 Connecting members 5 Support member 6 Fastening members 7. Sound-absorbing material 8. Expansion joint material (expansion rubber) 9. Baseboard 10 Slabs 11 Long structures 20 side wall 30 Beam 31 Discarded board 32 Finishing materials (flooring) 41 Joint surface 42 Support member mounting portion 43 Connection hole 51 Elastic base (vibration-proof rubber) 52 Support leg (support bolt) 53 Level adjustment nut 54 Support plate 61 volts 62 Nut

Claims

1. A double floor structure comprising a slab in a reinforced concrete building and a floor component provided on top of the slab, The floor constituent part is A joist consisting of a set of multiple long structures arranged closely together; A joist placed on the joist; A floor member laid on the floor joist; Support members that allow the joists to be arranged at intervals on the slab; A dry double floor structure characterized by having at least the following.

2. The dry double floor structure according to claim 1, characterized in that the joists are provided with connecting members that hold the long structures in close proximity.

3. The joists have a length equal to the length of the elongated structure from the vicinity of the side wall of the building to the beam of the building or the length between the beams of the building, The connecting members are provided at the longitudinal ends of the joists, hold the elongated structures close to each other, and connect the joists to each other in the longitudinal direction. The dry double floor structure according to claim 2.

4. The connecting member has a joint surface that is sized to expand outwardly in a direction perpendicular to the longitudinal direction of the joist, 4. The dry double floor structure according to claim 3, wherein the joists are connected by fastening the joint surfaces of the connecting members together so that they face each other.

5. 5. A dry double floor structure according to claim 2, wherein the joists are integral with the connecting members.

6. The dry double floor structure according to claim 5, wherein the joists and the connecting members are made of metal.

7. A dry double floor structure as described in any one of claims 2 to 4, characterized in that the support member is attached to the connecting member and installed near the side wall of the building and / or on a beam of the building.

8. The joists have a length equal to the length of the elongated structure from the vicinity of the side wall of the building to the beam of the building or the length between beams of the building, and are provided with connecting members at the longitudinal ends that hold the elongated structures close together and enable the joists to be connected in the longitudinal direction, and the connecting members have joint surfaces that are sized to expand outward perpendicular to the longitudinal direction of the joists and are fastened together to face each other, The joists and the connecting members are integrally formed from metal, The support member is attached to the connecting member and is installed near the side wall of the building and / or on a beam of the building. The dry double floor structure according to claim 1.

9. A dry double floor structure as described in any one of claims 1 to 4 or 8, characterized in that the joists have a bending rigidity such that when an impact load acts downward on the center part of the length, the deflection at the center part is 5 mm or less.

10. 9. A dry double floor structure according to claim 1, wherein the support member is provided with a nonlinear vibration-isolating rubber.

11. 9. A dry double floor structure according to claim 1, wherein the support member is provided with a level adjustment mechanism.

12. 9. The dry double floor structure according to claim 1, wherein a sound-absorbing material is installed between the slab and the floor member.

13. The dry double floor structure according to any one of claims 1 to 4 or 8, characterized in that the joists are a set of two long structures.

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