EP2412886B1 - Wooden building structure with several storeys - Google Patents

Description

Field of the invention

The invention relates to a new type of structure for multi-storey buildings mainly made of wood, benefiting from improved mechanical, thermal and especially anti-seismic and acoustic properties.

In particular because of its excellent antiseismic qualities, the structure of the invention is particularly applicable to the construction of multi-storey multi-family dwellings in areas prone to seismic shocks.

State of the art

The problem faced by the architect when considering the construction of a building, and particularly wood, is that he is confronted with contradictory criteria: the price of the land often imposes a construction in height, more sensitive to the wind and external solicitations. It is therefore necessary a priori a stable and rigid structure. But a rigid structure is a headache in terms of acoustic comfort (the propagation and especially the attenuation of structural noise). In addition, anti-seismic standards, whose legislators tend to widen the areas of application, encourage the design of lightweight structures whose assemblies must be both resistant and able to structurally absorb telluric energy. We must therefore favor structural junctions "direct" material on so-called junction "dry", free of flexible joint.

The energy balance requires extensive insulation of the outer casing, which implies the use of insulating materials, quite light almost by definition, while inside the building it is better to have a mass with high thermal inertia (weak point for wooden constructions) to ensure comfort in summer.

Acoustic comfort, on the other hand, would rather require heavy or non-rigid structures, presenting continuity solutions attenuating the power of vibratory waves through the junctions thus created (The vibratory weakening index through a junction is translated by the index K _ij ). We seek here to limit the transmission of noise from one room to another. The weight also represents a handicap from the seismic point of view. In fact, weight means substantial mass and strong inertia.

Finally, for serviceability and the limitation of deformation, the stability of the floors imposes a rigidity with a sufficient eigenmode, in order to ensure a good mechanical vibratory comfort (to limit the "rebound effect" of the floors).

More and more severe European standards frame these different criteria. The architect is therefore obliged to juggle contradictory and even contradictory criteria, so as to obtain the "least bad" possible solutions according to the desires of his clients.

Acoustically, the architect has formulas that take into account laboratory values (R _w , L _{nT, w} ) that essentially reflect direct transmission through the main wall compositions. The calculations thus made reflect, in practice, rarely the reality, a sign of a deep misunderstanding of the factors related to the indirect transmission of acoustic energy to the junctions (the modeling of these factors is still poorly controlled for wood constructions).

The problem is that these values do not reflect the "acoustic impedance" of complex structures, assemblies of materials (cavities, change of environment at the junctions, etc.) and that we are therefore obliged to resort to either methods extremely complex calculations or based on prediction formulas that are still difficult to master at the current research stage, or expensive empirical tests (and often a combination of both).

Wood constructions, regardless of their quality in other respects, are considered by poor construction workers as poor parents with regard to acoustic performance compared to traditional masonry constructions.

WO 02/06606 describes a "closed" freestanding floor structure consisting of two horizontal panels interconnected by honeycomb stiffening pieces. This structure being closed, it is on the one hand impossible to access its internal volume and on the other hand the multiple mechanical connections with the upper plate cause a high acoustic wave propagation.

CH-695 061 proposes a staged building structure according to the preamble of claim 1 formed of two horizontal panels completely decoupled, the space between these two panels being filled with a powder material such as sand or sawdust. In addition to inevitable settlement problems, this type of structure seems totally unsuitable in case of earthquake (because the overall structural bracing is mediocre). The presence of the powdery material favors displacements between the two panels and is therefore unfavorable for the resumption of vertical and horizontal forces.

EP 0 849 412 describes prefabricated elements of the closed box structure type, which, after assembly, are used for the construction of floors or walls. The assembly involves the existence of many joints that are all weak points in case of a sysmic shock. These elements do not have any particular properties that are effective neither from the point of view of acoustic decoupling nor from the seismic point of view.

The document US 5,685,124 describes high load capacity wood panels with good thermal and acoustic properties, especially for the construction of multi-storey buildings. In this document, the panels consist of ribs arranged sawtooth, sandwiched and fixed between plywood panels. The triangular section volumes determined by these ribs are filled on the one hand with thermal insulation and on the other hand with a heavy load, in particular gravel, intended - in theory - to improve the acoustic insulation. The ribs are actually many acoustic bridges and this system is therefore inefficient.

GB 1103853 discloses similar structural panels which comprise two outer plates between which a solid granular filler of high specific gravity and an elastic intermediate layer of sound insulation are inserted.

US 5205091 does not relate to wood structures but describes the use of a damping layer, which may be granular, arranged below tiled floors in multi-storey buildings to reduce impact noise transmissions to through these floors.

Summary of the invention

An object of the invention is to promote a prefabricated wooden building system immediately respecting the acoustic performance requirements between housing.

Another object of the invention is that this system allows rapid erection height over several floors and can use prefabrication, so as to reduce the cost.

Another object of the invention is the construction of wooden buildings meeting the requirements of stability, rigidity and strength required in seismic zones.

Another object of the invention is to be able to make large premises, with, in particular, bearing free floor areas of up to 8 m.

Another object of the invention is the placing on the market of buildings with a low ecological impact.

Another object of the invention is the development of an optimized wood structure, compact, to make the most of the volume of living rooms and to benefit from the aesthetic appearance of natural wood.

Another object of the invention is to reduce the volumes and transport costs.

Another object of the invention is to promote an improvement in the energy performance of buildings both in summer and in winter.

The object of the invention is a building structure with essentially wooden floors according to the wording of claim 1.

The advantage of such a structure lies first and foremost in its simplicity. Some of the structural elements that constitute it can be prepared in the workshop. On-site assembly is extremely simple and has a limited number of seals (considering the large size of the table).

We also achieve one of the objectives, that is to say, high acoustic performance between homes without resorting to extreme solutions such as the doubling of walls or the use of resilient joints.

Another advantage is that, in such a structure, the table thus designed has exceptional resistance from the point of view of bracing.

The presence of granular material gives the structure a high thermal inertia ideal for the comfort of the inhabitants in summer.

It will further be understood that when it is said that the table consists of a panel, this does not exclude that this panel itself consists of several juxtaposed panels, joined edge to edge in the same plane.

Another advantage is that the table of such a structure is presented as an open structure, which allows, during transport, to nest two floors one in the other, resulting in significant space and cost savings. 'energy.

The ribs of such a structure are advantageously made of a material selected from solid wood, solid butted wood, engineered wood, glue-laminated wood, reconstituted wood.

The ribs are preferably structurally fixed to the wood panel of the table by gluing, so that the contact surface ensures the cohesion of the reconstituted panel + rib section and thus increases the mechanical inertia characteristics of the panel . If necessary, this structural bonding may be replaced or supplemented by mechanical fasteners such as screws, tips, pins, etc. possibly sealed to the resin.

The degree of filling in granular material of the intermediate volume between two ribs is advantageously between 20 and 100%; it is preferably greater than 40%.

The volume possibly remaining between the granular material and the plane determined by the upper face of the ribs is preferably filled with an acoustic quality material chosen from mineral wool, felt, cellulose flakes, PET wadding or equivalents and their mixture.

The granular material preferably has a low absoption rate of moisture, a specific particle size of between 1 and 8 mm and a material or package which limits its moisture content to 15%.

The granular material is advantageously chosen from chippings, mineral aggregates such as sand, industrial residues such as clinker, crushed concrete.

The plane α determined by the upper face of the ribs is advantageously surmounted by a floating slab, a layer of resilient material being interposed between this plane and the floating slab.

The building structure comprises at least one upper vertical wall carrying essentially wood, these walls being fixed by fastening means in line with one of the ribs lining the table. Advantageously a trim panel (made of wood or other material), peripheral to the table, is disposed under the end face of this at least one wall and extends horizontally on the upper face of the ribs over a width corresponding at least to the distance separating two of these ribs. A resilient seal is disposed between the trim panel and the rib to which the at least one vertical wall is attached.

According to another advantageous embodiment, it comprises at least one upper vertical wall carrying substantially wood that goes lower than the plane α, and is fixed by means of attachment to a rib bank disposed flat on the bank of the table . The volume contiguous to this ridge and at the foot of the wall is filled with a mass of granular material. A resilient seal is disposed between the at least one vertical wall and the ridge rib to which it is attached.

According to a preferred embodiment, the at least one vertical wall consists of laminated panels or timber framing panel.

According to another advantageous embodiment, the fastening means comprise an acoustically decoupled threaded rod housed in a through hole. The ends of this threaded rod open into the dwellings arranged in the elements to be joined (for example, at the foot and at the top of the vertical walls of the junction). An intermediate centering washer placed in a concentric housing to the through hole prevents contact between the threaded rod and the through holes, avoiding the creation of an acoustic bridge.

According to another advantageous embodiment, the fastening means comprise an L-shaped bracket, at least one of the wings of this bracket having perforations surrounded by a conical bevel, this wing being fixed to the structure by means of screws or bolts with conical head of corresponding dimensions, a washer of resilient material being interposed between the chamfer and the head of these screws or bolts, so as to decouple acoustically, the other wing of this bracket being fixed to the table.

According to another advantageous embodiment, the fixing means comprise a plurality of blind holes formed horizontally in the thickness of a vertical panel, near its base, a vertical through hole connecting the base of each of these blind holes and the underside of the vertical panel. The height of a blind hole substantially corresponds to the length of an acoustically decoupled lag bolt introduced into the through hole and screwed into a rib. An anti-vibratory tip of resilient material is inserted between the head of the lag bolt and the inner wall of the through hole, thereby acting as an acoustic stabilizer.

The panel forming the table preferably has a thickness of at least 95 mm (depending on the loads to be resumed, it can however go down to values of the order of 60 mm). One of the advantages of this relatively large thickness is that the burning of wood only affects its lower surface layers, without altering the ability of the whole to support its load. Another advantage of this relatively large thickness, which combines with the large width of the elements of the table, is that the assembly [ribs + panel] has de facto excellent characteristics of structural inertia, which contributes to its strength. efficiency.

According to an advantageous embodiment, dividing walls separate two contiguous rooms A and B, each of these rooms having its own horizontal structure, distinct vertical walls, means of assemblies and separate floating screeds. The fixing means comprise an L-shaped bracket, at least one of the wings of this bracket having perforations surrounded by a conical bevel, this wing being fixed to the structure by means of screws or bolts with conical head of corresponding dimensions, a washer of resilient material being interposed between the chamfer and the head of these screws or bolts, so as to decouple them acoustically, the other wing of this bracket being fixed to the table. This bracket thus ensures the mechanical joining and the vibration cut of these two structures.

According to another advantageous embodiment, the fastening means comprise an acoustically decoupled threaded rod housed in a through hole, the ends of this threaded rod, opening into the housings formed in the elements to be joined, being tightened by bolts supported on distribution washers, an intermediate centering washer placed in a concentric housing to the through hole to prevent contact between the threaded rod and the through holes.

According to another advantageous embodiment, the structure comprises a dividing wall separating two adjoining rooms A and B. Each of these rooms has its own own horizontal structure of means of assemblies and separate floating screeds. The edge ribs of the two adjoining floors are secured through a wedge held in the upper position by decoupled lag bolts, a resilient seal being placed above the lower wall, in line with the upper middle wall, ensuring the mutual decoupling of the structures of the junction.

Brief description of the figures

• La Fig.1 est une vue schématique en coupe des différents modes de propagation de l'énergie acoustique entre deux pièces contiguës ;
• La Fig.2 est une vue en coupe verticale, d'un complexe de plancher d'une structure suivant l'invention;
• La Fig.3 est une vue en coupe verticale d'un détail de réalisation d'une structure suivant la Fig.2;
• La Fig.4 est une vue bâtarde (partiellement en coupe verticale suivant un plan perpendiculaire à celui de la Fig. 2, partiellement en perspective) de la structure de la Fig.2 ;
• La Fig.5 est une vue en coupe verticale d'une autre forme de réalisation d'une structure suivant l'invention;
• La Fig. 6 est une vue bâtarde (partiellement en coupe verticale suivant un plan perpendiculaire à celui de la Fig.5, partiellement en perspective) d'une structure suivant l'invention ;
• La Fig.7 est une vue en coupe verticale d'un détail de réalisation d'une structure suivant la Fig.5;
• La Fig.8 est une vue en coupe verticale d'une autre forme de réalisation d'une structure suivant l'invention;
• La Fig.9 est une vue en coupe verticale d'une cloison mitoyenne d'un bâtiment suivant l'invention;
• La Fig.10 est une vue en coupe verticale d'un détail de réalisation d'un assemblage antivibratoire paroi inférieure/plancher d'un bâtiment ne faisant pas partie de l'invention;
• Les Fig. 11 et 12 sont des vues en coupe verticale, respectivement de profil et de face, d'une autre forme de réalisation du découplage acoustique d'une fixation structurelle mur /plancher suivant l'invention;
• Les Fig. 13 et 14 sont des vue en coupe verticales de détails de deux autres formes de réalisation du liaisonnement avec découplage acoustique de la jonction de deux éléments du bâtiment de l'invention.
• La Fig. 15 est une vue en coupe verticale d'une autre forme de réalisation d'une cloison mitoyenne d'un bâtiment suivant l'invention.

These and other aspects of the invention will be clarified in the detailed description of particular embodiments of the invention, with reference to the drawings of the figures, in which:

• The Fig.1 is a schematic sectional view of the different modes of propagation of the acoustic energy between two adjacent rooms;
• The Fig.2 is a vertical sectional view of a floor complex of a structure according to the invention;
• The Fig.3 is a vertical sectional view of a detail of embodiment of a structure according to the Fig.2 ;
• The Fig.4 is a bastard view (partially in vertical section along a plane perpendicular to that of the Fig. 2 , partially in perspective) of the structure of the Fig.2 ;
• The Fig.5 is a vertical sectional view of another embodiment of a structure according to the invention;
• The Fig. 6 is a bastard view (partially in vertical section along a plane perpendicular to that of the Fig.5 partially in perspective) of a structure according to the invention;
• The Fig.7 is a vertical sectional view of a detail of embodiment of a structure according to the Fig.5 ;
• The Fig.8 is a vertical sectional view of another embodiment of a structure according to the invention;
• The Fig.9 is a vertical sectional view of a partition of a building according to the invention;
• The Fig.10 is a vertical sectional view of an embodiment of a lower wall / floor antivibration assembly of a building not forming part of the invention;
• The Fig. 11 and 12 are views in vertical section, respectively of profile and face, of another embodiment of the acoustic decoupling of a wall / floor structural fastening according to the invention;
• The Fig. 13 and 14 are vertical sectional views of details of two other embodiments of the bonding with acoustic decoupling of the junction of two elements of the building of the invention.
• The Fig. 15 is a vertical sectional view of another embodiment of a partition of a building according to the invention.

The figures are not drawn to scale. Generally, similar elements are denoted by similar references in the figures.

Detailed description of particular embodiments

The structure of the invention is a coherent overall approach to economically and simply regulate the safety and comfort of the occupants.

The Fig. 1 schematically shows the different modes of propagation of acoustic energy between two parts separated by a wall. Direct transmission (arrow A) is done directly through the partition wall. It is observed that a significant part of the energy is propagated by indirect transmission, via the side walls (arrows B1, B2, B3). Finally, some of the energy is spread by air (parasitic transmission, arrow C). The junction between the walls (dotted circle K _ij ) therefore plays an important role.

The transmission of waves via the side walls for a type of junction considered, requires in-depth research on the index K _ij of each of the 3 indirect transmission channels (B1, B2, B3). These are the latter that drop the effective acoustic performance of a construction, measured in situ, compared to its apparent performance, measured in the laboratory.

In residential wood construction, the practical tests of noise insulation between dwellings show that, on average, we rarely exceed a value D _{nT, w} of 40 dB. It is therefore difficult to imagine, that we can achieve without walls the insulation values of 54 dB in airborne noise imposed by standards for comfort described as "normal" from one apartment to another. Indeed, it is known that doubling the mass of the components of a wall increases the attenuation by only 4 dB!

In addition, there are the requirements for standard acoustic insulation for impact noises. Indeed, the transmission of shocks through solid materials is 10 ⁶ times greater than for airborne noise.

To try to meet the new standards, traditional solutions, without worrying too much about lateral transmissions at the junctions, are based on a mass-spring-mass or mass-air-mass concept, which involves the doubling of all the walls of the premises. transmitter and receiver, according to the principle "box in the box", which is expensive, binding (significant loss of space) and potentially gives rise to many defects (we must therefore use a hand of very skilled work). In addition, the wooden structure is hidden, we lose the very warm and decorative atmosphere provided by the use of wood.

The properties of the structure of the invention are based firstly on the structure of the element separating two stages (table 1), which assumes both the function of ceiling (for a lower stage) and of the floor (for an upper stage) - These two names can be used interchangeably in the description below - and on the other hand on the connecting elements between the different parts.

The Fig.2 shows, in section, an embodiment of a horizontal structure 1 (ceiling / floor) of a building according to the invention.

The lower part of this structure 1 is a table formed by a panel 2 consisting of solid wood planks stacked in layers crossed at 90 ° and bonded structurally to each other over their entire surface (said laminated panel), whose lower face 4 forms the ceiling of a first room or a first floor. This panel 2 is secured, at its upper face 6, to a series of wooden ribs 8 (seen here end). This joining is preferably done by gluing-pressing, so that the assembly [panel 2 + rib 8] reacts as a single structure, which increases the structural inertia.

The use of panels made of solid wood planks stacked in crossed layers as described above, precisely because of the cross-orientation of the fibers that make it up, makes it possible to take back both longitudinal and transversal stresses, so that we have a structure that can cover very large surfaces (multiple of 2.4 m floor width) without risk of abnormal deformation and in compliance with the self-imposed mode for vibration stability. The interval between two ribs 8, adapted according to the intended range, is filled with granular material (here, gravel) over a certain height, which can go up to the total height of the ribs 8.

As an illustration, we have shown on the Fig. 2 different heights of filling, but it goes without saying that in practice, the same height is generally respected in a given floor. This height varies from 20% to 100%, and is generally above 40%. We can also alternate the filling heights on two or more ribs. The filling height can in no case exceed 100%, as is the case in CH 695 061 , considered the closest state of the art. Indeed, as mentioned above, this would be equivalent to placing a ball bearing between the lower face and the upper face of the structure, totally ruining the bracing ability, with the catastrophic results that can be imagined in case of earthquake .

In practice, the grit, after spillage, undergoes a certain settlement (generally of the order of 8 to 12%). It is however possible to fill the rejection ribs and complete the filling after mechanical settlement, according to the requirements to be met.

The use of chippings has four major advantages: it is a heavy material, which easily absorbs noises and vibrations; it is a material that has a high thermal inertia; it is a discontinuous material, which therefore has a high acoustic impedance; it is finally an easy material to move. It is therefore possible to pass sheaths and conduits without problem, even after the event.

The ribs 8 here have a vertical rectangular section, but one can also consider a horizontal rectangular section, square, I or C, depending on the stresses to resume. The upper face of the ribs 8 determines a plane α, which corresponds to the base of the floor of the room of an upper floor. The possible gap between the gravel and the plane α is filled (partially or completely) with a lightweight absorbent material 12, such as rockwool, for example.

It is understood that the ceiling thus formed forms an open structure, which must be able to resume all solicitations (shocks, loads, etc.) from the upper floor. The structure as developed is already extremely rigid, and avoids the trampoline effect, even on large spans. Note that this structure is "paradoxical" from the point of view of the skilled person, since the ribs work in compression and are therefore subject to a risk of buckling (if they are poorly sized), which would not be the case if they were classically laid out below the table.

On the base formed by this structure, one can now install any form of adequate floor. Given the acoustic performance required, it is generally used a floating floor. A resilient layer 14 (for example a decoupling felt) is extended along the plane α, so as to cover the gravel. A floating peripheral panel 16 (made of wood, laminated or glulam, OSB or the like) of a width allowing it to rest on the two extreme ribs (8, 24) is extended to form an intermediate layer (optional) , above which we place a resilient layer 18, on which one comes to place the floating screed 20 (which can be of dry or wet type), taking care that it is nowhere in direct contact with the supporting structure, which would ruin for sure all precautions taken at this stage. To this end, the elastic layer 18 rises in plinth 21 along the upper vertical wall 22 to complete the acoustic decoupling. Where appropriate, the floating peripheral panel 16 consists of 2 pieces (as shown in FIG. Fig.2 ) to facilitate the subsequent discharge of gravel on site. This peripheral panel (optional) partially and laterally deflects the acoustic energy, according to the _desired attenuation K _ij .

All the precautions taken so far mainly (but not exclusively) aim at preventing the direct propagation of noise and vibrations from one floor to another, in addition to the anti-seismic effect. However, as the extensive research and testing carried out by the inventors has shown, most of the inconvenience associated with the propagation of noise in a building comes mainly from the lateral propagation of the energy generated by the vibrations. lateral propagation can account for up to 2/3 of the energy involved). Efforts have therefore been made to reduce this lateral propagation as much as possible, particularly at the junction between the vertical walls 22 and the horizontal structures 1 (ceilings / floors). We notice at the Fig.2 (and in more detail at Fig.3 ) that the end rib 24 ("so-called edge rib") of the horizontal structure 1 has a wider section than the other ribs 8.

This feature strengthens the end of the table and facilitates the installation of fasteners, such as a bracket 26, one of whose wings 28 sits on the surface of the rib 24 projecting inwardly, the other wing 30 being fixed to the upper vertical wall 22.

To hinder the path of noise and vibrations without altering the strength of the building, three acoustic "decoupling means" are interposed "in series" between the different parts of the structure, as can be seen in Fig. 3 . First, an absorbent elastic layer 32, placed between the outer rib 24 and the peripheral panel 16, then a decoupling washer 33 (playing a stabilizing role) interposed between the screw head 34 with conical head and the corresponding wing 28 of the bracket 26. A second elastic layer 36 (acting as an acoustic isolator) is disposed between the bracket 26 itself and the peripheral panel 16 of the structure.

The centering of the screws 34 relative to the perforations of the square is an essential element from the point of view of acoustics. Washer 33 provides a welcome centering function for assemblers. The position of the bracket 26 can obviously be reversed, as well as that of the decoupling means 33, 36.

It will be well aware that these different resilient layers must each meet very specific specifications and that their compositions and their mechanical characteristics can vary widely. Among the compositions selected, mention may be made of organic or synthetic felts of different densities, needle felt, rubber (natural or recycled), synthetic materials such as Kevlar, PUR, etc.

An additional resilient seal 38 (optional) is placed in a groove in the peripheral panel 16.

The Fig. 4 shows the structure of a building according to the invention under construction, partially in perspective and partially in section along a plane perpendicular to that of the Fig. 2 . The ribs 8 are here seen longitudinally. A continuous edge piece 40 (shown in perspective) dug with mortises 42 provides both sealing, vertical continuity of the structure, alignment and maintenance of the ends of the ribs 8. It closes the volumes between the ribs where the gravel will subsequently be dumped (usually by pumping).

The brackets 26 are here arranged on the ends of the ribs 8. Note the presence, here too, of a plate 16 peripheral to the horizontal structure 1, which creates an additional change of medium and leads to a better distribution of energy and a strengthening of the junction.

Tests show that the addition of the peripheral plate 16 and the fact of having positioned the fixing of the vertical wall above the ribs (according to the plane α) alone produce an attenuation comparable to what would have been obtained. by doubling all the walls (walls and ceiling).

The Fig.5 to 7 show another advantageous embodiment of the connection between a horizontal structure 1 and the facade walls 22.

The end rib 24 of the embodiment shown in FIGS. Figures 2 to 4 here is replaced by a bank rib 44 laid flat. The upper vertical wall 22, slightly elongated with respect to the previous embodiment, rests on this edge rib 44 so as to close the volume for the gravel. Here, depending on the nature and the importance of the forces dimensioning the structure, a conventional square 26 or a reinforced square 46 is used here. Fig. 7 ) a decoupling washer 33 (playing a stabilizing role) is interposed between the screw heads 34 with conical heads (bolting) and the corresponding wing of the bracket 26, 46. A second elastic layer 36 (acting as an acoustic insulator) is disposed between the bracket 26, 46 itself and the structure 1. A wooden tongue 48 is arranged between the brackets, so as to facilitate subsequent access to the screws 34 and constitute a support for the screed.

As figured in the top of the Fig. 6 , the brackets 26, 46 are here arranged on the transverse rib 40 and no longer on the ribs 8.

The brackets 26, 46 being below the floating slab 20, there is obtained a space saving in the horizontal plane: the yoke extends 20, without obstacle, to the vertical wall 22. The resilient plinth 21 interposed between the clevis 20 and the upper vertical wall 22 is extended downward so as to cover the vertical flange 30 of the bracket 26, 46.

The Fig.8 shows, in cross section, an alternative embodiment of the assembly of the structure according to the invention. The table 2 is here fixed to the vertical wall 22 not by brackets, but by a wooden profile (or other similar material) 49 flush with the plane α. Alternately horizontal and vertical perforations enable this profile 49 to be fixed to the edge rib and to the vertical wall by means of lag bolts, screws or other fastening means 50.

• Conventionnel non découplé, de préférence dans le cas d'une fixation haute (sur le plan α) : des équerres en L, éventuellement renforcées et fixées par des pointes torsadées ou des vis à bois en nombre suffisant pour s'adapter aux efforts structurels
• Découplé renforcé : une équerre en L de préférence renforcée, au moins une des ailes de cette équerre présentant des perforations entourées d'un chanfrein conique, cette aile étant découplée du bois par un joint résilient structurel « isolateur » et fixée à la structure par l'intermédiaire de vis ou boulons à tête conique de dimensions correspondantes. Une rondelle en matériau résilient, faisant office de stabilisateur, est interposée entre le chanfrein et la tête conique de ces vis ou boulons, de façon à les découpler acoustiquement. Le chanfrein peut être réalisé de différentes façons, notamment par usinage, emboutissage ou par bouterolage. Il contribue notamment au centrage des vis ou boulons. Ce centrage revêt une grande importance pour le découplage acoustique.

• Découplé à tire-fonds : une équerre en L, de préférence renforcée, au moins une des ailes de cette équerre présentant au moins un trou plus large permettant le placement d'une rondelle résiliente d'isolation entre le tire-fond et l'équerre. Cette rondelle résiliente (de préférence à base de kevlar ou équivalent) assurera la reprise des efforts parallèles à cette au moins une des ailes et selon la nature et l'importance des efforts dimensionnant la structure. Au dessus et en dessous de cette rondelle d'isolation et prenant appui de part et d'autre de cette au moins une aile sont placés respectivement un stabilisateur situé sous une rondelle métallique (elle-même située sous la tête du tire-fond) et en dessous entre cette au moins une aile et le bois est placé un joint résilient structurel assurant un rôle d'isolateur acoustique.
• Découplé à tige traversante : pour reprise d'efforts importants (voir plus bas) une tige cylindrique filetée à chaque extrémité reçoit, dans des logements aménagés, deux écrous et rondelles métalliques de serrage. Trois rondelles résilientes dont celle du centre placée dans un logement adéquat, assurent le centrage de la tige en évitant ainsi son contact avec les trous traversants. Les deux autres rondelles résilientes, placées aux extrémités, assurent le découplage des panneaux à serrer. Dans ce cas il est préférable de placer des joints plats résilients pour assurer le découplage structurel des panneaux à serrer.

It has thus been seen that the means for fixing the vertical walls are generally of 4 types:

• Non-decoupled conventional, preferably in the case of a high fixation (on the α plane): L-shaped brackets, possibly reinforced and fixed by twisted spikes or wood screws in sufficient number to adapt to structural efforts
• Decoupled reinforced: an L-shaped bracket preferably reinforced, at least one of the wings of this square with perforations surrounded by a conical chamfer, this wing being decoupled from the wood by a resilient structural seal "insulator" and fixed to the structure by means of screws or bolts with conical head of corresponding dimensions. A washer of resilient material acting as a stabilizer is interposed between the chamfer and the conical head of these screws or bolts, so as to decouple acoustically. The chamfer can be made in different ways, including machining, stamping or burring. It contributes in particular to the centering of the screws or bolts. This centering is of great importance for acoustic decoupling.

• Decoupled from lag bolts: An L-shaped bracket, preferably reinforced, at least one of the wings of this bracket having at least one wider hole allowing the placement of a resilient insulation washer between the lag bolt and the bracket . This resilient washer (preferably based on Kevlar or equivalent) will ensure the recovery of parallel forces to this at least one of the wings and according to the nature and importance of efforts sizing the structure. Above and below this insulating washer and supported on either side of this at least one wing are placed respectively a stabilizer located under a metal washer (itself located under the head of the lag bolt) and below this at least one wing and the wood is placed a structural resilient seal providing an acoustic isolator role.
• Uncoupled with through rod: to recover significant forces (see below) a cylindrical rod threaded at each end receives, in housing, two nuts and metal washers clamping. Three resilient washers, including the central one in a dwelling adequate, ensure the centering of the rod thus avoiding contact with the through holes. The other two resilient washers, placed at the ends, ensure the decoupling of the panels to be clamped. In this case it is preferable to place resilient flat joints to ensure the structural decoupling of the panels to be clamped.

The Fig. 9 is a sectional elevation of a dividing wall separating two rooms of the same floor. All components of an exterior wall assembly (as described in Fig. 2 to 8 ) are here. However, the acoustic problem is complicated by the need to attenuate the noise and vibrations passing between two adjacent rooms. It is no longer possible to use a "simple" or "continuous" sign (through), otherwise you will get highly degraded results. This problem is solved by uncoupling parts A and B between them: each has its own horizontal structure 1A and 1B, separate vertical walls 22A and 22B, means of assemblies and separate floating screeds. A layer of light resilient material 52 acoustically separates the two structures thus contiguous. The mechanical anchoring by anchoring of these two structures (without degradation of the acoustic performances) is obtained (as described above) by means of a threaded through rod which connects the two juxtaposed floors (which face each other) and opening into two cavities which are arranged (usually by ripping) in the thickness of the floor to receive on each of its ends, a washer and a clamping nut. Three resilient washers provide acoustic decoupling of one floor from the other. The central washer (preferably in Kevlar) also ensures the centering of the threaded rod and acts as a damping stop of the deformation movements in the slide.

Depending on the results to be obtained, that is to say according to the standard of comfort that applies, it is also possible, as shown for part B, to double at least on one side the wall of a wall conventional anti-noise consisting of gypsum board 54 or fibroplâtre fixed by resilient profiles 56 and separated from the vertical wall 22 by a vacuum of about 20 mm.

The performance of this noise barrier is improved if care is taken to reverse this doubling from one floor to another (as shown in FIG. Fig.9 ).

The Fig. 10 shows a form of fastening not forming part of the invention between the panel 2 of the table 1 and the corresponding lower vertical panel 22 with the aid of a lag bolt 58. Of course, care must also be taken to ensure acoustic decoupling between the two elements 2, 22 below. For this purpose, the lag bolt 58 is inserted into a through-hole 60 with a diameter much greater than that of the rod 61 of the lag bolt 58. Decoupling and centering are provided on the side of the head of the lag bolt 58. a cylindrical stabilizing tip 62 of resilient material whose bottom surface is slightly tapered, and the side of the rod 61 by another centering means 64 such as a tip, a washer or, as shown here, an O-ring 64 In this way, a rigid assembly is obtained without any acoustically detrimental contact between the panel 2 and the lag bolt 58. A resilient isolator seal 66 is interposed between the panel 2 and the top of the vertical panel 22. A profile of Ceiling angle (not shown) may, if necessary, subtract this seal 66 from the users view.

The Fig. 11 and 12 show another method of assembly between a rib 8 of the table 1 and an upper vertical panel 22. A blind hole 68 is formed (generally by ripping) in the thickness of the vertical panel 22, near his base. A through hole 70 connects the base of this blind hole 68 and the underside of the panel 22. The height of the blind hole 68 corresponds substantially to the length of a lag screw 72, which allows the introduction of this lag screw. 72 in the through hole 70 and its screwing into the rib 8. The diameter of the lag bolt is chosen according to the stresses to be resumed. A tip of resilient material 74 is inserted between the head 75 of the lag bolt 72 and the inner wall of the through hole 70, thereby acting as an acoustic stabilizer and centering. The head 75 of the lag screw has a slight taper so as to favor the centering of the rod in the through hole 70. Fig. 10 , the through hole 70 has a diameter much greater than that of the rod of the lag bolt 72. A bearing washer 76 (optional) (shown in FIG. Fig. 12 ) makes it possible to distribute the loads on a larger surface of wood. Furthermore, since the fastener is closer to the axis of the panel 22 (and / or the axis of a support column), the reversal torque of the panel 22 is more symmetrical. The presence of the assembly is hidden by a plinth 78 or a decorative panel. It is therefore possible to control the state of fixation after an earthquake.

The Fig. 13 and 14 each show a connection and decoupling mode, respectively between two wall elements ( Fig. 13 ) and floor ( Fig. 14 ). This mode of connection is particularly suitable for buildings highly exposed to the earthquake and / or having a large number of floors (The present structure makes it possible to easily reach heights of 20 floors). It comprises a threaded rod 80, housed in a through hole 82, (of a diameter greater than that of the threaded rod 80) passing right through the rim ribs (24) of a floor 1. At the Fig. 13 , each end of the threaded rod 80 opens into a housing 84 (usually formed by cutting). These dwellings 84 are arranged at the foot and at the top of the vertical walls 22 of the junction.

To the Fig. 14 each of the ends of the threaded rod opens on the distal face of one of the ribs 24 to be secured. Centering means 64 (on the Fig.13 , an intermediate washer, on the Fig. 14 , a tip), placed in a concentric housing to the through hole 82 avoids contact between the rod 80 and a rigid element of the structure, avoiding the creation of an acoustic bridge.

Clamping is performed at each end of the rod 80, by means of a nut 86 pressing a metal washer 88, putting the required pressure on an antivibration washer 90 that it overcomes. This clamping also ensures the loading of the elastic seal (s) 66 placed against the floor.

An advantage of this mode of connection is that a control of the junctions (clamping and state of the decoupling washers acoustic) is always possible after a possible earthquake.

As can be seen from Fig. 13 a single resilient seal 66 located above the floor is sufficient under the upper vertical wall. There is therefore no need for joint on the lower vertical wall, which is an advantage if the occupant wishes to take advantage of the decorative appearance of the wood, because no resilient seal is visible on the ceiling of the lower room.

In this case (as shown) it is possible to arrange a housing for the centering disc, made for example in Kevlar, at the lower part of the floor 1.

This fastening device is particularly suitable for a building with 20 floors subjected to considerable seismic efforts.

The fig.15 presents another advantageous embodiment for a common wall separating two rooms of the same floor. As in Fig.9 all the constituent elements of an exterior wall assembly are found, but the acoustic problem is complicated by the need to attenuate the noise and vibrations passing between two adjacent rooms. Unlike the Fig. 9 , here we opted for a simple separation wall, which allows in particular to keep a "wood" finish of the walls, and to obtain a smaller footprint, without degrading the sound insulation or seismic performance. Although there are two _lower walls 22 and 22 _upper and two floors 1A, 1B separated from each other, this structure behaves as if there was only one vertical structural wall 22 ( cheaper - there is less wood - and more robust), and allows large spans "free of support" (greater than 7.5 m).

The rib ribs 24 of the two contiguous floors 1A, 1B are secured through a wedge 92 placed in the upper position (for example 8 mm multiplex) by decoupled lag bolts 50 (symbolized in the drawing by simple lines ). This wedge 92 deflects the lateral transmission, which has to travel a very long way (see the arrow on the fig.15 ), given the presence of a resilient seal 94 above the lower wall. A single structural resilient seal 94 (6 to 8 mm) is sufficient (one could even, at the limit, remove it if one accepts that the R _Ff "flanking" ceiling does not exceed 54 dB), which is an advantage for the anti-seismic aspect (and also for the aesthetics) of the structure. Similarly, at the junction of the floors, it is sufficient to completely decouple a single floor 1B to obtain a perfect decoupling from the second floor 1A. The load of the upper structure is centered and distributed over the joint 94. The junction of the 1B floor relative to the lower wall is operated by means of oblique screws 96. The doubling of the two side walls 22 is made here by a wood panel 3 ply 3 (the thickness is calculated for an optimum critical frequency), separated by a thickness It will be apparent to those skilled in the art that the present invention is not limited to the examples illustrated and described above. The invention comprises each of the novel features as well as their combination as defined in the claims. The presence of reference numbers can not be considered as limiting. The use of the term "includes" in no way excludes the presence of other elements other than those mentioned. The use of the definite article "a" to introduce an element does not exclude the presence of a plurality of these elements. The present invention has been described in relation to specific embodiments, which have a purely illustrative value and should not be considered as limiting.

Claims (18)

1. Building structure with storeys substantially made of wood comprising:

   - a table (1) comprised of a wooden panel (2), the lower face (4) of this table (1) forming the ceiling of a room of a first storey, with the upper face of this table (1) constituting the base of a floor of a room of a storey above the first storey;

   - a plurality of wooden ribs (8) structurally secured to the upper face of this panel (2), with the panel (2) and the rib (8) together forming a self-supporting structure of the open type wherein the table (1) works in extension and the ribs (8) in compression, with the upper portion of these ribs (8) determining a plane (α);

   - a load of granular material (10) placed in the intercalary spaces determined by the upper face of at least one panel (2) and the opposite faces of two neighbouring ribs (8),

   the structure being characterised in that:

   (a) the wooden panel (2) is comprised of solid wood boards stacked in layers crossed at 90° and glued structurally between them across their entire surface, in that

   (b) the load of granular material (10) has a density between 1100 and 1700 kg/m3 and in that

   (c) the structure comprises at least one upper vertical bearing wall (22) substantially made of wood, with this at least one upper vertical wall (22) being fastened by means of fastening (26) plumb of an end rib (24, 44) arranged at the end of the table (1), with a resilient seal (32, 38, 66) being arranged between the upper vertical wall (22) and the end rib (24, 44) to which it is fastened.
2. Building structure according to claim 1, characterised in that the ribs (8) are constituted of a material chosen from solid wood, jointed solid wood, glued wood, laminated wood, reconstituted wood.
3. Building structure according to any of claims 1 or 2, characterised in that the ribs (8) are fastened to the table (1) by structural pressing-gluing.
4. Building structure according to any of claims 1 to 3, characterised in that the fill rate in granular material (10) of the intercalary volume between two ribs (8) is between 20 and 100%.
5. Building structure according to claim 4, characterised in that the fill rate in granular material (10) of the intercalary volume between two ribs (8) is greater than 40%.
6. Building structure according to any of the preceding claims, characterised in that the volume remaining between the granular material (10) and the plane (α) determined by the upper face of the ribs (8) is filled at least partially with an acoustic quality material (12) chosen from among mineral wool, felt, PET cotton wadding or the equivalents and mixtures thereof.
7. Building structure according to any of the preceding claims, characterised in that the granular material (10) has a specific granulometry between 1 and 8 mm.
8. Building structure according to any of the preceding claims, characterised in that the granular material (10) is selected from gravel, mineral granulates such as sand, industrial wastes such as slag and crushed concrete.
9. Building structure according to any of the preceding claims, characterised in that the plane (α) determined by the upper face of the ribs (8) is overmounted with a floating floor screed (20), with a layer of resilient material (18) being inserted between this plane (α) and the floating floor screed (20).
10. Building structure according to any of the preceding claims, characterised in that a seat panel (16) peripheral to the table (1), is arranged under the end face of this at least one upper vertical wall (22) and extends over the upper face of the ribs (8) over a width corresponding to at least the distance separating two of these ribs (8).
11. Building structure according to any of claims 1 to 9, characterised in that the at least one upper vertical wall (22), descends lower than the plane (α), with the end rib (44) being arranged flat at the end of the table, with the volume contiguous to this end rib (44) and to the foot of the upper vertical wall (22) being filled with a mass of granular material (10).
12. Building structure according to any of the preceding claims characterised in that the at least one vertical wall (22) is comprised of glued panels or timber frame panels.
13. Building structure according to any of the preceding claims, characterised in that the means of fastening (26), include an acoustically decoupled threaded rod housed in a through hole, with the ends of this threaded rod, opening into the housings arranged in the elements to be joined, being clamped by bolts pressed on distribution washers, an intermediary centring washer placed in a housing concentric to the through hole making it possible to prevent all contact between the threaded rode and the through holes.
14. Building structure according to any of the preceding claims, characterised in that the means of fastening (26) include an L-shaped square (26), with at least one of the wings (28, 30) of this square (26) having perforations surrounded by a conical chamfer, with this wing (28) being fixed to the structure by the intermediary of countersunk screws or bolts (34) of the corresponding dimensions, a washer made of a resilient material (33) being inserted between the chamfer and the head of these screws or bolts (34), in such a way as to decouple them acoustically, with the other wing (30, 28) of this square being fastened to the table (1).
15. Building structure according to any of the preceding claims, characterised in that the means of fastening include a plurality of blind holes (68) arranged horizontally in the thickness of a vertical panel (22), near its base, with a vertical through hole (70) connecting the base of each of these blind holes (68) and the lower face of the vertical panel (22), the height of the blind hole 68 corresponding substantially to the length of an acoustically decoupled threaded element (72, 80) introduced into the through hole (70) and screwed into a rib (8), an end made of resilient material (74) being inserted between the head (75) of the threaded element (72, 80) and the inside wall of the through hole (72).
16. Building structure according to any of the preceding claims, characterised in that the panel (2) forming the table has a thickness of at least 95 mm.
17. Building structure according to any of the preceding claims, which includes a common wall separating two contiguous rooms A and B, with each of these rooms having its own horizontal structure (1A, 1B), means for assemblies and separate floating floor screeds characterised in that the end ribs (24) of the two contiguous floors 1 are secured through a prop (92) maintained in high position by decoupled lag bolts.
18. Building structure according to claim 17 characterised in that a resilient seal (94) is placed above the lower wall, plumb of the upper common wall, providing the mutual decoupling of the structures of the junction.

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