JP2023109409A - Buffer material for building, building, and construction method of building foundation - Google Patents

Abstract

To provide buffer material for a building, the building, and a construction method of a building foundation.SOLUTION: A buffer material 10 for a building is arranged between a building foundation and an existing pile buried in the ground. The buffer material 10 comprises: a rubber elastic part 11 having elasticity; and an upper side plate provided on an upper surface of the elastic part 11. The elastic part 11 has a plurality of elastic elements 15. The plurality of elastic elements 15 are arranged via spaces so as to be compressively deformed upon vertical compression of the elastic elements 15.SELECTED DRAWING: Figure 4

Description

BACKGROUND OF THE DISCLOSURE The present disclosure relates to building cushioning members, buildings, and construction methods for building foundations.

In some cases, a new building is built on the ground where the existing piles are left (for example, Patent Document 1). In the technique described in Patent Literature 1, existing piles are reused when rebuilding a building. For example, a laminated rubber or isolator is placed between the pile head of the existing pile and the foundation of the building.

JP-A-2002-47668

When building a new building on the ground where the existing piles are left, there are cases where the existing piles buried in the ground are not used. For example, avoiding existing piles to form the foundation of a building. However, due to the design of the building, it may not be possible to avoid all existing piles when constructing the foundation, and some piles may be placed under the foundation. In this case, there is a possibility that the buildings will settle differently in the future.

(1) A buffering member for a building that solves the above problems is a buffering member that is arranged between the foundation of the building and existing piles buried in the ground, the buffering member comprising an elastic elastic portion made of rubber, and an upper plate provided on the upper surface of the elastic portion, the elastic portion having a plurality of elastic portions, the plurality of elastic portions being compressively deformable when the elastic portions are vertically compressed. are arranged through the space.

According to this configuration, the cushioning member is deformed by the force received from the building. For example, when a building subsides due to ground subsidence, the elastic portion deforms according to the amount of subsidence (distance of subsidence) of the building. As a result, in the foundation, the pile upper portion located on the existing pile and the portion other than the pile upper portion settle in the same manner, and uneven settlement of the building can be suppressed.

(2) The cushioning member for a building according to (1) above further includes a lower plate provided on the lower surface of the elastic portion, wherein the lower plate is arranged parallel to the upper plate. According to this configuration, the elastic portion can be easily and uniformly deformed between the upper plate and the lower plate.

(3) In the cushioning member for buildings according to (1) or (2) above, the cushioning member has a vertical rigidity of 5000 kN/m or less. According to this configuration, the cushioning member is appropriately deformed by the weight of the building. For this reason, it is less likely that the shock-absorbing member will act as an obstacle during ground subsidence and hinder the subsidence of the building.

(4) In the cushioning member for a building according to (3) above, the cushioning member has a vertical rigidity of 300 kN/m or more. According to this configuration, it is possible to support the portion of the foundation that is in contact with the cushioning member.

(5) In the cushioning member for a building according to any one of (1) to (4) above, the elastic portions are arranged so as not to contact each other. According to this configuration, since a space is provided around the elastic portion, it is easy to compressively deform the elastic portion.

(6) In the cushioning member for a building according to (5) above, the elastic portion has a first elastic portion and a second elastic portion as the plurality of elastic portions, and the first elastic portion includes , an annular portion, wherein the second elastic portion is configured to be disposed within the annular portion of the first elastic portion. According to this configuration, it is possible to prevent water or soil from entering the inside of the first elastic portion. As a result, deterioration of the second elastic portion can be suppressed.

(7) In the cushioning member for a building according to any one of (1) to (4) above, the plurality of elastic portions are connected to each other by elastic connecting portions. According to this configuration, since the plurality of elastic portions are connected to each other by the connecting portion, local crushing of the elastic portion is suppressed.

(8) In the cushioning member for a building according to (7) above, the elastic portion includes, as the elastic portions, an outer peripheral portion forming an outer periphery of the elastic portion, a land portion provided within the outer peripheral portion, It has a first connecting portion that connects the land portions, and a second connecting portion that connects the outer peripheral portion and the land portion. According to this configuration, it is possible to suppress the intrusion of water or soil into the outer peripheral portion. This can suppress deterioration of the land portion in the outer peripheral portion.

(9) A building that solves the above problems is a building that is installed on the ground in which existing piles are embedded, and is equipped with any one of the cushioning members of (1) to (8) above. The foundation has a downward protrusion, the foundation is constructed such that a portion of the downward protrusion is positioned above the existing pile, and the cushioning member is provided between the downward protrusion and the existing pile. placed in between. According to this configuration, the cushioning member is deformed by the force received from the building. This makes it possible to suppress uneven subsidence of the building.

(10) A building foundation construction method for solving the above problems includes a first step of cutting off the head of an existing pile that is scheduled to be placed under the downward protrusion of the foundation; A second step of arranging a buffer member on the existing pile, a third step of rolling a region including the existing pile in the ground, and a fourth step of forming the foundation on the ground that has been rolled. According to this configuration, it is possible to form a foundation that is less likely to cause differential settlement of the building.

According to the cushioning member for a building, the building, and the method for constructing the foundation of the building according to the present disclosure, differential settlement of the building can be suppressed.

It is a schematic diagram of a building. It is a perspective view of a cushioning member. It is a side view of a buffer member. FIG. 4 is a cross-sectional view of the cushioning member taken along line 4-4 of FIG. 3; FIG. 4 is a cross-sectional view of the cushioning member taken along line 5-5 of FIG. 3; FIG. 4 is a partial cross-sectional view of the cushioning member, explaining the action of the cushioning member; It is a sectional view of the 1st modification of a buffer member. FIG. 11 is a cross-sectional view of a second modified example of the cushioning member; FIG. 11 is a cross-sectional view of a third modified example of the cushioning member; FIG. 12 is a cross-sectional view of a fourth modified example of the cushioning member;

1 to 6, the construction method of the cushioning member 10 of the building 1, the building 1, and the foundation 5 of the building 1 will be described.

<Building>
Examples of buildings 1 include facilities such as residences, shops, public halls, and hospitals. A building 1 is provided on the ground 3 in which the existing piles 2 are buried. For example, soft ground is reinforced by driving piles. Even with the ground 3 reinforced in this way, the ground 3 may harden with the passage of time, and the building 1 may be constructed directly on the ground 3 in some cases. In such a case, the building 1 is erected directly on the ground 3 while avoiding the existing piles 2. - 特許庁However, when the existing piles 2 are not used, it is difficult to provide the foundation 5 while avoiding all the existing piles 2 . For this purpose several piles are arranged under the foundation 5 . In the building 1 of this embodiment, one or several existing piles 2 are placed under the foundation 5 .

As shown in FIG. 1 , for example, a building 1 includes a foundation 5 and a building body 6 provided on the foundation 5 . The foundation 5 of the building 1 has a downward projection 5A. In a continuous foundation, the downward projecting portion 5A is a footing. In a raft foundation, the downward projecting portion 5A is a portion provided along the periphery of the foundation so as to protrude downward. A foundation 5 is constructed such that a portion of the downward projecting portion 5A is positioned on the existing pile 2. As shown in FIG. When the footing is configured to follow the outer periphery of the foundation, the foundation 5 is configured to overlap the existing pile 2 at one or several locations along the entire circumference of the footing. A cushioning member 10 is arranged between the downward projecting portion 5A and the existing pile 2 . The cushioning member 10 will be described below.

<Buffer material>
The cushioning member 10 will be described with reference to FIGS. 1 to 6. FIG. As shown in FIG. 1, the cushioning member 10 is arranged between the existing pile 2 buried in the ground 3 and the downward projecting portion 5A (for example, footing) of the foundation 5. As shown in FIG.

As shown in FIGS. 2 and 3 , the cushioning member 10 includes an elastic rubber-made elastic portion 11 and an upper plate 12 provided on the upper surface of the elastic portion 11 . The cushioning member 10 may further include a lower plate 13 . The lower plate 13 is provided on the lower surface of the elastic portion 11 . The lower plate 13 is arranged parallel to the upper plate 12 .

Upper plate 12 and lower plate 13 are made of resin. The upper plate 12 and the lower plate 13 are made of resin that is difficult to deform under the load applied from the building 1 . The load applied from the building 1 is 10 kN or more and 50 kN or less. A load of 10 kN or more and 50 kN or less (hereinafter referred to as assumed load) is a value assumed as a force applied to one existing pile 2 when the building 1 is a house or a structure similar to a house. By forming upper plate 12 and lower plate 13 from resin, corrosion of upper plate 12 and lower plate 13 can be suppressed.

Resins for the upper plate 12 and lower plate 13 include acrylic resin, polystyrene resin, polycarbon resin, PET (polyethylene terephthalate resin), and ABS resin (acrylonitrile, butadiene and styrene copolymer resin). The resin forming the upper plate 12 and the lower plate 13 may contain ceramic-based or glass-based fillers.

When a load of 10 kN or more and 50 kN or less is applied, the cushioning member 10 is vertically compressed and deformed by the load. A load of 10 kN or more and 50 kN or less is the above assumed load.

In one example, the cushioning member 10 is configured to have a vertical stiffness of 5000 kN/m or less. The cushioning member 10 is configured to have a vertical stiffness of 300 kN/m or more. In another example, the cushioning member 10 is configured to have a vertical stiffness of 4000 kN/m or less. In yet another example, cushioning member 10 is configured to have a vertical stiffness of 3000 kN/m or less.

In one example, the cushioning member 10 is configured circular in plan view. The diameter of the cushioning member 10 is set according to the size of the head of the existing pile 2 . The diameter of the cushioning member 10 is 200 mm or more and 600 mm or less. The thickness of the cushioning member 10 is 100 mm or less.

The elastic portion 11 is made of natural rubber or synthetic rubber. The elastic portion 11 may be a laminate of a natural rubber member and a synthetic rubber member. Synthetic rubbers include styrene-butadiene rubber, acrylonitrile-butadiene rubber, ethylene-propylene rubber, and butadiene rubber.

When it is assumed that the maximum thickness reduction width of the elastic portion 11 is 10 mm, the thickness of the elastic portion 11 is set to 30 mm or more and 70 mm or less. The maximum width of reduction is defined as "original thickness of elastic portion 11" - "assumed thickness of elastic portion 11 after compression change". The maximum reduction is equal to the assumed value of land subsidence.

When the area of the upper plate 12 in plan view is defined as the total area, the elastic portion 11 is configured to occupy 10% or more and 50% or less of the total area in plan view. In one example, the elastic portion 11 is configured to occupy an area of 15% or more and 25% or less of the total area in plan view.

The elastic part 11 has a plurality of elastic parts 15 . The elastic portion 15 is made of rubber. The elastic portion 15 is fixed to the upper plate 12 and the lower plate 13 by an adhesive.

The plurality of elastic parts 15 are arranged with a space S therebetween so as to be compressively deformable when the elastic parts 15 are compressed in the vertical direction. The plurality of elastic portions 15 may be arranged so as not to contact each other, or the plurality of elastic portions 15 may contact each other.

As shown in FIGS. 4 and 5, in this embodiment, the plurality of elastic parts 15 are arranged so as not to contact each other.
For example, the elastic portion 11 has a first elastic portion 16 and a second elastic portion 17 . Furthermore, the elastic portion 11 has a third elastic portion 18 . The first elastic portion 16 has a first annular portion 16A. The second elastic portion 17 has a second annular portion 17A. The third elastic portion 18 has a third annular portion 18A. The first elastic portion 16, the second elastic portion 17, and the third elastic portion 18 are formed by bending a rubber rope having a rectangular cross section into an annular shape. The cross-section of the rubber rope may be circular or elliptical.

The second elastic portion 17 is arranged within the first annular portion 16A of the first elastic portion 16 so as not to contact the first elastic portion 16 . A first space SA is provided between the first elastic portion 16 and the second elastic portion 17 .

The third elastic portion 18 is arranged within the second annular portion 17A of the second elastic portion 17 so as not to contact the second elastic portion 17 . A second space SB is provided between the second elastic portion 17 and the third elastic portion 18 .

"Compressive deformation" in this embodiment will be described with reference to FIG. When a load is applied to the cushioning member 10 and the cushioning member 10 is compressed, the vicinity of the middle of the elastic portion 15 in the vertical direction expands. In this manner, deformation in which the elastic portion 15 near the middle thereof becomes larger than its original thickness is "compressive deformation". Since the elastic portion 15 is compressed and deformed, the subsidence of the building 1 is not hindered.

<Foundation construction method>
The construction method of the foundation 5 includes first to fourth steps. In the first step, after the ground 3 is excavated, the heads of the existing piles 2 to be arranged under the downward projecting portion 5A (for example, footing) of the foundation 5 are cut off. An example of the existing pile 2 is, for example, a concrete pile. In this case, the head of the existing pile 2 is cut by a breaker. Furthermore, the cut surface of the existing pile 2 is processed flat. By applying mortar to the cut surface of the existing pile 2, the cut surface may be flattened. When the existing pile 2 is a steel pile, the head of the steel pile is cut by a cutting machine. Furthermore, a flat plate is provided on the cut surface of the steel pile.

In the second step, a cushioning member 10 is arranged on the existing pile 2 whose head has been cut off. The cushioning member 10 is fixed to the cut surface of the existing pile 2 with an adhesive. The cushioning member 10 is fixed to the cut surface of the existing pile 2 so as not to be displaced from the existing pile 2 in the subsequent rolling compaction process.

In the third step, a region including the existing piles 2 in the ground 3 is compacted. In one example, the entire area where the foundation 5 is to be constructed (hereinafter referred to as foundation construction area) is subjected to first rolling compaction by a roller compactor. After the first rolling compaction, crushed stone is laid on the foundation building area and the second rolling compaction is carried out.

Note that the first rolling compaction may be omitted. Crushed stone may be placed on the cushioning member 10 . Also, the crushed stone does not have to be placed on the cushioning member 10 . A spacer may be placed on the cushioning member 10 instead of the crushed stone. Styrofoam is mentioned as a spacer.

In the fourth step, a foundation 5 is made on the compacted ground 3 . The foundation 5 is formed by an existing construction method. For example, the foundation 5 is formed by assembling reinforcing bars, assembling a formwork for the foundation 5, and then pouring concrete into the formwork.

The operation of this embodiment will be described.
When the ground 3 under the foundation 5 of the building 1 subsides and the earth pressure pushing the lower surface of the foundation 5 decreases, the load of the building 1 concentrates on the cushioning members 10 arranged on the existing piles 2 . Then, the cushioning member 10 is pushed and deformed by compression. When the ground 3 around the cushioning member 10 is compacted by lowering the position of the upper surface of the cushioning member 10 and the soil pressure rises, the foundation 5 is supported by the ground 3 and the force applied to the cushioning member 10 is relatively become smaller. In this way, when the ground subsides, stress concentrates on the cushioning member 10 before the building 1 tilts, and the cushioning member 10 is compressed and deformed. Therefore, when the ground subsides, the building 1 subsides without tilting. In this way, differential settlement of the building 1 is less likely to occur.

Effects of the present embodiment will be described.
(1) The cushioning member 10 includes an elastic portion 11 and an upper plate 12 provided on the upper surface of the elastic portion 11 . The elastic part 11 has a plurality of elastic parts 15 . The plurality of elastic parts 15 are arranged with a space S therebetween so as to be compressively deformable when the elastic parts 15 are compressed in the vertical direction.

According to this configuration, the cushioning member 10 is deformed by the force received from the building 1 . For example, when the building 1 sinks due to ground subsidence, the elastic portion 11 deforms according to the amount of subsidence (distance of subsidence) of the building 1 . As a result, in the foundation 5, the pile upper portion located on the existing pile 2 and the portion other than the pile upper portion settle in the same manner, so that uneven settlement of the building 1 can be suppressed.

When constructing the foundation 5 on the existing pile 2, it is necessary to greatly cut off the head of the existing pile 2 in order to reduce the influence of the existing pile 2. - 特許庁In this respect, according to the cushioning member 10, it is sufficient to cut off the head portion of the existing pile 2 to the extent that the cushioning member 10 can be arranged on the existing pile 2. Thus, when constructing the foundation 5 on the ground 3 where the existing piles 2 exist, the pretreatment work for the existing piles 2 can be reduced.

(2) The cushioning member 10 further includes a lower plate 13 . The lower plate 13 is arranged parallel to the upper plate 12 . According to this configuration, the elastic portion 11 can be easily and uniformly deformed between the upper plate 12 and the lower plate 13 .

(3) The vertical rigidity of the cushioning member 10 is 5000 kN/m or less. According to this configuration, the cushioning member 10 is appropriately deformed by the weight of the building 1 . Therefore, a situation in which the cushioning member 10 acts as an obstacle and hinders the subsidence of the building 1 during ground subsidence is less likely to occur.

(4) The vertical rigidity of the cushioning member 10 is 300 kN/m or more. According to this configuration, the portion of the base 5 with which the cushioning member 10 contacts can be supported.

(5) The elastic parts 15 are arranged so as not to contact each other. According to this configuration, since the space S is provided around the elastic portion 15, the elastic portion 15 can be easily compressed and deformed.

(6) The elastic portion 11 has a first elastic portion 16 and a second elastic portion 17 . The first elastic portion 16 has an annular portion. The second elastic portion 17 is arranged within the annular portion of the first elastic portion 16 . According to this configuration, it is possible to prevent water or soil from entering the inside of the first elastic portion 16 . As a result, deterioration of the second elastic portion 17 can be suppressed.

Moreover, such an elastic part 11 may be formed from a rubber rope. For example, the first elastic portion 16 is formed by bending a rubber rope into an annular shape. By preparing the rubber rope in advance in this manner, the elastic portion 11 can be easily formed at the construction site. Therefore, even if the existing pile 2 is found unexpectedly, the newly found existing pile 2 can be quickly dealt with, so that the delay from the foundation construction plan can be shortened.

(7) The building 1 is provided with the cushioning member 10 . The foundation 5 of the building 1 is constructed such that a portion of the downwardly protruding portion 5A (eg, footing) is positioned above the existing piles 2 . The cushioning member 10 is arranged between the downward projecting portion 5A and the existing pile 2 . According to this configuration, the cushioning member 10 is deformed by the force received from the building 1 . Thereby, differential settlement of the building 1 can be suppressed.

(8) The construction method for the foundation 5 of the building 1 includes first to fourth steps. In the first step, the head of the existing pile 2 to be arranged under the downward projecting portion 5A of the foundation 5 is cut off. In the second step, a cushioning member 10 is arranged on the existing pile 2 whose head has been cut off. In the third step, a region including the existing piles 2 in the ground 3 is compacted. In the fourth step, a foundation 5 is made on the compacted ground 3 . According to this configuration, the foundation 5 that makes it difficult for the building 1 to settle unevenly can be formed.

<Modification>
The above-described embodiments are examples of possible forms of the construction method of the cushioning member 10 of the building 1, the building 1, and the foundation 5 of the building 1, and are not intended to limit the forms. The method of constructing the cushioning member 10 of the building 1, the building 1, and the foundation 5 of the building 1 may take forms different from those exemplified in the above embodiments. Examples thereof include a form in which a part of the configuration of the embodiment is replaced, changed, or omitted, or a form in which a new configuration is added to the embodiment. Modifications of the embodiment are shown below.

In the cushioning member 10 of the embodiment, the third elastic portion 18 may be omitted. The cushioning member 10 may also have additional elastic regions 15 . The additional elastic portion 15 may be arranged within the third annular portion 18A of the third elastic portion 18 .

A first modification of the cushioning member 10 will be described with reference to FIG.
In the first modified example, unlike the cushioning member 10 of the embodiment, the plurality of elastic portions 15 are connected to each other by elastic connecting portions 20 . The connecting portion 20 is made of rubber. For example, the elastic portion 11 includes an outer peripheral portion 21 as the elastic portion 15, a land portion 22 as the elastic portion 15, a first connecting portion 23 that connects the land portions 22, and the outer peripheral portion 21 and the land portion 22. and a second connecting portion 24 to be connected. The outer peripheral portion 21 constitutes the outer periphery of the elastic portion 11 . The land portion 22 is provided within the outer peripheral portion 21 . The land portion 22 may be in contact with the outer peripheral portion 21 or may be separated from the outer peripheral portion 21 . The outer peripheral portion 21, the land portion 22, the first connecting portion 23, and the second connecting portion 24 are made of a rubber rope having a rectangular cross section. The rubber rope may have a circular cross section. Even with such a configuration, the same effect as that of the embodiment can be obtained. In addition, since the plurality of elastic portions 15 are connected to each other by the connecting portion 20, the elastic portion 11 is prevented from being locally crushed. In addition, it is possible to prevent water or soil from entering the outer peripheral portion 21 . As a result, deterioration of the land portion 22 in the outer peripheral portion 21 can be suppressed.

A second modification of the cushioning member 10 will be described with reference to FIG.
The elastic portion 11 of the second modified example has a plurality of land portions 22 as the elastic portion 15 . The land portions 22 are arranged so as not to contact each other. The land portions 22 are arranged vertically and horizontally. According to this configuration, since the space S is provided around the land portion 22, the elastic portion 15 can be easily compressed and deformed. Even with such a configuration, the same effect as that of the embodiment can be obtained.

A third modification of the cushioning member 10 will be described with reference to FIG. The elastic portion 11 of the third modified example has an annular first elastic portion 16, an annular second elastic portion 17, and an annular third elastic portion 18 as in the embodiment. Each of the first elastic portion 16, the second elastic portion 17, and the third elastic portion 18 is rectangular in plan view. Furthermore, the upper plate 12 and the lower plate 13 are rectangular in plan view. With such a configuration, the same effect as that of the embodiment can be obtained.

A fourth modification of the cushioning member 10 will be described with reference to FIG. The elastic portion 11 of the cushioning member 10 has an outer peripheral portion 21 as the elastic portion 15 and a plurality of land portions 22 as the elastic portion 15 . The outer peripheral portion 21 is configured in an annular shape. The outer peripheral portion 21 constitutes the outer periphery of the elastic portion 11 . The land portion 22 extends straight. A plurality of land portions 22 are provided within the outer peripheral portion 21 . A plurality of land portions 22 are arranged parallel to each other with a space S therebetween. In FIG. 10, the land portion 22 contacts the outer peripheral portion 21, but the land portion 22 may be separated from the outer peripheral portion 21. FIG. With such a configuration, the same effect as that of the embodiment can be obtained.

S... Space, 1... Building, 2... Existing pile, 3... Ground, 5... Foundation, 5A... Lower protruding part, 10... Cushioning member, 11... Elastic part, 12... Upper plate, 13... Lower plate, 15 Elastic portion 16 First elastic portion 17 Second elastic portion 20 Connecting portion 21 Peripheral portion 22 Land portion 23 First connecting portion 24 Second connecting portion.

Claims (10)

A cushioning member placed between the foundation of a building and existing piles buried in the ground,
An elastic part made of rubber having elasticity, and an upper plate provided on the upper surface of the elastic part,
The elastic portion has a plurality of elastic parts, and the plurality of elastic parts are arranged with a space therebetween so as to be compressively deformable when the elastic parts are compressed in the vertical direction.
buffer material for buildings. further comprising a lower plate provided on the lower surface of the elastic portion,
the lower plate is arranged parallel to the upper plate;
The cushioning member for a building according to claim 1. The vertical rigidity of the buffer member is 5000 kN/m or less,
3. A buffer member for a building according to claim 1 or 2. The vertical rigidity of the buffer member is 300 kN/m or more,
The cushioning member for a building according to claim 3. the elastic portions are arranged so as not to contact each other;
A buffer member for a building according to any one of claims 1 to 4. The elastic portion has a first elastic portion and a second elastic portion as the plurality of elastic portions,
The first elastic portion has an annular portion,
the second elastic portion is configured to be disposed within the annular portion of the first elastic portion;
The cushioning member for a building according to claim 5. The plurality of elastic parts are connected to each other by elastic connecting parts,
A buffer member for a building according to any one of claims 1 to 4. The elastic portion includes, as the elastic portions, an outer peripheral portion forming an outer periphery of the elastic portion, a land portion provided within the outer peripheral portion, a first connecting portion connecting the land portions, and the outer peripheral portion. a second connecting portion that connects with the land portion;
The cushioning member for a building according to claim 7. A building built on the ground where existing piles are buried,
Equipped with the cushioning member according to any one of claims 1 to 8,
the foundation of the building has a downward protrusion, the foundation is constructed such that a portion of the downward protrusion is located on the existing pile;
The buffer member is arranged between the downward protrusion and the existing pile. A construction method for a building foundation, comprising:
a first step of cutting off the head of an existing pile that is to be placed under the downward projection of the foundation;
a second step of arranging a cushioning member on the existing pile whose head has been cut;
a third step of rolling a region including the existing pile in the ground;
a fourth step of forming the foundation on the compacted ground;
A construction method for building foundations.

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