SEISMIC ISOLATION APPARATUS FOR STRUCTURES, METHOD FOR INSTALLING APPARATUS THEREOF, AND SEISMIC ISOLATION MEMBER
The seismic isolation apparatus 1 is an apparatus for damping the vibrations of an upper section A of a structure with respect to a lower section B of the structure, and provided with a plurality of U-shaped seismic isolation members 10, a first coupling plate 20 to which one end of the seismic isolation member 10 is fixed, and a second coupling plate 30 to which the other end of the seismic isolation member 10 is fixed. The seismic isolation members 10A are placed between the first coupling plate 20 and the second coupling plate 30 in a direction. The seismic isolation members 10B are placed between the first coupling plate 20 and the second coupling plate 30 in a direction oppose to the direction of the seismic isolation members 10A.
The present invention relates to a seismic isolation apparatus for structures, a method for installing the seismic isolation apparatus and a seismic isolation member.
This application claims priority to Japanese Patent Application No. 2007-279148 filed on Oct. 26, 2007, the content of which is incorporated herein by reference in its entirety.
BACKGROUND ART OF THE INVENTIONConventionally, in structures such as buildings, bridges, elevated roads and elevated railways, there has been proposed a seismic isolation apparatus which is placed between an upper section such as a building frame of a structure and a lower section such as a foundation of the structure, thus damping the vibrations of the upper section to the lower section when exposed to large amounts of energy such as when earthquakes occur. For example, Patent Documents 1 to 3 below have disclosed a seismic isolation apparatus which is in combination with an isolator, and a damping mechanism between the upper section and the lower section.
In the above seismic isolation apparatus, the isolator made by alternately stacking metal plates and plate-shaped elastic bodies is interposed between the upper section and the lower section and fixed to both of them. The upper section is supported by the lower section via the isolator. A damping mechanism is constituted with a plurality of seismic isolation members (curved members) made of an elastic-plastic material. The plurality of seismic isolation members are placed regularly in the vicinity of the isolator (for example, in a radial manner), and the seismic isolation members are fixed individually, more specifically, one end thereof is fixed to the upper section while the other end is fixed to the lower section. In the damping mechanism, when large amounts of energy act on a structure by which the upper section vibrates in a horizontal direction with respect to the lower section, for example, when earthquakes occur, seismic isolation members undergo plastic deformation to absorb the seismic energy. In other words, the energy incoming to the upper section is absorbed so that the seismic isolation members can undergo plastic deformation.
- PATENT DOCUMENT 1: Japanese Patent No. 3533110
- PATENT DOCUMENT 2: Japanese Patent No. 3543004
- PATENT DOCUMENT 3: Japanese Unexamined Patent Application, First Publication No. 2004-340301
In the above-described conventional seismic isolation apparatus, the curved member as a seismic isolation member is placed parallel with a vibration direction to attain the highest energy absorption efficiency. Therefore, on the assumption that energy is incoming to the seismic isolation apparatus from all directions, it is intended that an equal seismic isolation performance is attained constantly even when the energy is incoming from some particular direction. For this reason, in designing a seismic isolation member, it is necessary to make a highly detailed evaluation. Further, as a result of the above evaluation, particular restrictions are imposed on the shape of the seismic isolation member, and the seismic isolation member must be accurately manufactured based on these restrictions so as to provide a predetermined shape.
Therefore, in the conventional seismic isolation apparatus, an excessive amount of labor is spent at the design stage and also at the manufacturing stage, resulting in an increased manufacturing cost.
The present invention has been made in view of the above circumstances, an object of which is to provide a seismic isolation apparatus for structures higher in production efficiency both at the design stage and at the manufacturing stage and lower in manufacturing cost, a method for installing the apparatus, and a seismic isolation member.
Means for Solving the ProblemsIn order to attain the above object, the present invention provides a seismic isolation apparatus for damping the vibrations of an upper section of a structure with respect to a lower section of the structure. The seismic isolation apparatus is provided with a plurality of U-shaped seismic isolation members, a first coupling plate to which one end of the seismic isolation member is fixed, and a second coupling plate to which the other end of the seismic isolation member is fixed. Some of the plurality of the seismic isolation members are placed between the first coupling plate and the second coupling plate in a predetermined direction, and the other of the plurality of the seismic isolation members are placed between the first coupling plate and the second coupling plate in a direction opposed to the predetermined direction.
In the seismic isolation apparatus of the present invention, both ends of the seismic isolation member may be fixed with bolts respectively to the first coupling plate and the second coupling plate. Each one of the bolts may be disposed at a portion by fixing one end of the seismic isolation member to the first coupling plate and a portion of the other end of the seismic isolation member to the second coupling plate, or may be disposed plurally at the respective portions. For example, three bolts are used for fixture, each of the bolts is preferably placed so as to be located at the vertex of a triangle. Further, both ends of the seismic isolation member maybe welded respectively to the first coupling plate and the second coupling plate.
In the seismic isolation apparatus of the present invention, recesses into which one end or the other end of the seismic isolation member is fitted are formed respectively on the first coupling plate and the second coupling plate, and both ends of the seismic isolation member may be fitted respectively into the recesses and fixed thereafter to the first coupling plate and the second coupling plate.
The seismic isolation apparatus of the present invention may includes an isolator having metal plates and plate-shaped elastic bodies alternately stacked. It is preferable that the isolator be placed between the upper section and the lower section.
The present invention provides a method for installing a seismic isolation apparatus having a first coupling plate to be fixed to a lower section of a structure, a second coupling plate to be fixed to an upper section of the structure opposing the lower section, and a plurality of seismic isolation members fixed respectively to the first coupling plate and the second coupling plate between the first coupling plate and the second coupling plate so as to be placed toward a predetermined direction and a direction opposing the predetermined direction, on the lower section and the upper section. This installation method includes a step of disposing the seismic isolation apparatus on the lower section so that the seismic isolation members are set along a previously assumed direction of vibrations of the upper section to the lower section, a step of fixing the seismic isolation apparatus to the lower section, a step of disposing the upper section on the seismic isolation apparatus and a step of fixing the seismic isolation apparatus to the upper section.
The present invention provides a seismic isolation member placed between an upper section and a lower section, thereby damping the vibrations of the upper section to the lower section which are generated in a previously assumed direction by its own plastic deformation. This seismic isolation member is formed in a U-shape and placed between the upper section and the lower section along the previously assumed direction of vibrations, one end of which is fixed to the lower section and the other end of which is fixed to the upper section.
In the present invention, in a case where large amounts of energy, for example, earthquakes, act on the structure including a upper section and a lower section, thereby vibrating the upper section with respect to the lower section in a direction in which seismic isolation members are placed, the seismic isolation members undergo plastic deformation so as to be displaced in a direction in which one end is spaced away from the other end, thereby consuming the energy which is incoming to the upper section. As a result, the vibrations of the upper section are damped.
According to the present invention, a direction in which vibrations are incoming is assumed previously, and the seismic isolation members are placed so as to be set along the assumed direction, thus making it possible to effectively damp the vibrations of the upper section which are generated in the assumed direction. In other words, in the present invention, since it is not assumed that energy is incoming from all directions but assumed that the energy is incoming only from a specific direction, there is no necessity for making a detailed evaluation in designing the seismic isolation members, unlike a conventional case. Further, since no particular restrictions are imposed on the shape of the seismic isolation members, there is no necessity for raising the machining accuracy of the seismic isolation members to the extent of conventional seismic isolation members.
Advantageous Effect of the InventionThe seismic isolation apparatus of the present invention is higher in production efficiency both at the design stage and at the manufacturing stage and therefore lower in manufacturing cost.
1: SEISMIC ISOLATION APPARATUS
10, 10A, 10B: SEISMIC ISOLATION MEMBER
13, 14: BRACKET PORTION
20: FIRST COUPLING PLATE
22: COUNTER BORING (CORRESPONDING TO A RECESS OF THE PRESENT INVENTION)
24: RECESS
30: SECOND COUPLING PLATE
40: BOLT
50, 60, 70: SEISMIC ISOLATION MEMBER
A: UPPER SECTION
B: LOWER SECTION
BEST MODE FOR CARRYING OUT THE INVENTIONA description will be given of embodiments of the seismic isolation apparatus of the present invention by referring to
As shown in
The seismic isolation member 10 is a narrow rod-shaped steel product and bent at its intermediate portion so as to give a U-shape, when viewed from the side. Bracket portions 13 and 14 greater in width than other portions are disposed respectively on two paired ends 11 and 12 of the seismic isolation member 10. The seismic isolation member 10 is similar in dimension at any portions excluding the bracket portions 13 and 14. The bracket portions 13 and 14 are disposed so as to be parallel to each other. Two through-holes (not illustrated) are formed respectively at the bracket portions 13 and 14.
The first coupling plate 20 is a rectangular-shaped steel plate uniform in thickness, and one end 11 of each seismic isolation member 10 is fixed to the upper face via a bolt 40. A bolt hole (not illustrated) into which the bolt 40 is screwed is formed on the upper face of the first coupling plate 20. A plurality of stud bolts 21, which are buried into a lower section of a structure on fixing the seismic isolation apparatus 1 of the present embodiment to the lower section, are installed upright on the lower face of the first coupling plate 20.
The second coupling plate 30 is also a rectangular-shaped steel plate uniform in thickness, and the other end 12 of each seismic isolation member 10 is fixed to the lower face via a bolt 40. A bolt hole (not illustrated) into which the bolt 40 is screwed is formed on the lower face of the second coupling plate 30. A plurality of stud bolts 31, which are buried into a upper section of the structure on fixing the seismic isolation apparatus 1 of the present embodiment to the upper section, are installed upright on the upper face of the second coupling plate 30.
Of eight seismic isolation members 10, four seismic isolation members 10A are placed at equal intervals along a side 20a of the first coupling plate 20 and also oriented in a direction orthogonal to the side 20a, by which one end 11 is fixed to the upper face of the first coupling plate 20 via the bolt 40. Further, these four seismic isolation members 10A are placed at equal intervals along a side 30a of the second coupling plate 30 and also oriented in a direction orthogonal to the side 30a, by which the other end 12 is fixed to the lower face of the second coupling plate 30 via the bolt 40.
Of eight seismic isolation members 10, four other seismic isolation members 10B are placed at equal intervals along the other side 20b of the first coupling plate 20, in other words, along the other side 20b parallel with the side 20a to which the four seismic isolation members 10A are fixed, and also oriented in a direction orthogonal to the other side 20b, by which one end 11 is fixed to the upper face of the first coupling plate 20 via the bolt 40. Further, these four seismic isolation members 10B are placed at equal intervals along the other side 30b of the second coupling plate 30, in other words, along the other side 30b parallel with the side 30a to which the four seismic isolation members 10A are fixed, and also oriented in a direction orthogonal to the other side 30b, by which the other end 12 is fixed to the lower face of the second coupling plate 30 via the bolt 40.
The four seismic isolation members 10A and the other four seismic isolation members 10B are fixed to the first coupling plate 20 and the second coupling plate 30. The seismic isolation members 10A are arranged so that curved portions of the seismic isolation members 10A are projected from between the first coupling plate 20 and the second coupling plate 30 in a predetermined direction. The seismic isolation members 10B are arranged so that curved portions of the seismic isolation members 10B are projected from between the first coupling plate 20 and the second coupling plate 30 in a direction opposite to the predetermined direction. In other words, the seismic isolation members 10A are placed in a positive direction indicated by the two-headed arrow X in
The above-constituted seismic isolation apparatus 1 is disposed between the upper section A such as a building frame and the lower section B such as a foundation in the structure according to the following steps.
In the structure, for example, like a bridge girder to be placed on a bridge pier, a direction of vibrations of the upper section A to the lower section B is assumed previously. On the basis of such an assumption, first, the seismic isolation apparatus 1 is placed on the lower section B so that the seismic isolation members 10A and 10B are set along the previously assumed direction of vibrations of the upper section A (the two-way (positive/negative) direction indicated by the two-headed arrow X in
Subsequently, the upper section A is placed on the seismic isolation apparatus 1. As described above, the stud bolts 31 are installed upright on the upper face of the second coupling plate 30 in the seismic isolation apparatus 1, and the seismic isolation apparatus 1 is fixed to the upper section A in such a manner that the stud bolts 31 are buried into the upper section A. In addition, although not illustrated, the stud bolts 31 are coupled to the reinforcing steel disposed inside the upper section A, by which the seismic isolation apparatus 1 is more strongly coupled to the upper section A.
As described above, the seismic isolation apparatus 1 is disposed between the upper section A and the lower section B. In a case where large amounts of energy such as earthquakes act on the structure including the upper section A and the lower section B, thereby vibrating the upper section A with respect to the lower section B in a direction in which the seismic isolation members 10 are placed (the two-way (positive/negative) direction indicated by the two-headed arrow X in
According to the seismic isolation apparatus 1, a direction in which vibrations are incoming is assumed previously, and the seismic isolation members 10 are placed so as to be set along the assumed direction (the two-way (positive/negative) direction indicated by the two-headed arrow X in
Therefore, production efficiency of the seismic isolation apparatus 1 can be raised both at the design stage and at the manufacturing stage, thus resulting in a lower manufacturing cost of the seismic isolation apparatus 1.
In the above-described seismic isolation member 50, if each one bolt 40 is used as fixing means for the coupling plates 20 and 30, the coupling plates 20 and 30 may be fixed at a lower strength. However, in a case where vibrations act on the seismic isolation apparatus 1 in a direction other than the above-assumed direction, there is an advantage that the bolt is less likely to loosen. Further, the seismic isolation apparatus 1 is made up of a smaller number of components, thus making it possible to reduce the manufacturing cost.
In the above-described seismic isolation member 60, the number of bolts 40 is increased as fixing means for the coupling plates 20 and 30, thereby the coupling plates 20 and 30 can be fixed more strongly. Further, the bolts 40 are disposed so as to be located at the vertices of a triangle. Therefore, in a case where vibrations act on the seismic isolation apparatus 1 in a direction other than the assumed direction, there are advantages that the bolts are less likely to loosen as compared with a case where the coupling plates are fixed by using two bolts, and the number of the bolts is increased to reduce the size of each bolt.
In the above-described seismic isolation member 70, the coupling plates 20 and 30 can be fixed more strongly. Further, the seismic isolation apparatus 1 is made up of a smaller number of components, thus making it possible to reduce the manufacturing cost.
In the above-described seismic isolation apparatus 1, one bracket portion 13 of the seismic isolation member 10 is fitted into the counter boring 22 formed on the first coupling plate 20 and both of them are then fixed to each other, thus making it possible to fix more strongly the first coupling plate 20 of the seismic isolation member 10. Similarly, the other bracket portion 14 of the seismic isolation member 10 is fitted into a counter boring formed on the second coupling plate 30 and both of them are then fixed to each other, thus making it possible to fix more strongly the seismic isolation member 10 to the second coupling plate 30. Further, a part of the force generated on the seismic isolation member 10 can be directly transferred to the first coupling plate 20 by bearing pressure acting on a contact surface between the bracket portion and the counter boring, thereby reducing the force retained by the bolt 40. As a result, the bolt 40 can be reduced in diameter, or the number of the bolts 40 can be decreased.
In the above-described seismic isolation apparatus 1 as well, the seismic isolation member 10 can be fixed more strongly to the first coupling plate 20 and to the second coupling plate 30. Further, the force retained by the bolt 40 is reduced, and similar effects as described above can be attained accordingly.
Incidentally, in the above embodiment, only the X direction in
The first coupling plate 120 is a rectangular-shaped steel plate uniform in thickness, and one end 11 of each seismic isolation member 10 is fixed to the upper face via a bolt 40. A bolt hole (not illustrated) into which the bolt 40 is screwed is formed on the upper face of the first coupling plate 120. A plurality of stud bolts 21 are installed upright on the lower face of the first coupling plate 120.
The second coupling plate 130 is also a rectangular shaped steel plate uniform in thickness, and the other end 12 of each seismic isolation member 10 is fixed to the lower face via a bolt 40. A bolt hole (not illustrated) into which the bolt 40 is screwed is formed on the lower face of the second coupling plate 130. A plurality of stud bolts 31 are installed upright on the upper face of the second coupling plate 30.
Of eight seismic isolation members 10, two seismic isolation members 10C are placed at equal intervals along a side 120a of the first coupling plate 120 and also oriented in a direction orthogonal to the side 120a, by which the other end 11 is fixed to the upper face of the first coupling plate 20 via the bolt 40. Further, these two seismic isolation members 10C are placed at equal intervals along a side 130a of the second coupling plate 130 and also oriented in a direction orthogonal to the side 130a, by which the other end 12 is fixed to the lower face of the second coupling plate 130 via the bolt 40.
Of eight seismic isolation members 10, two other seismic isolation members 10D different from the above two members are placed at equal intervals along a side 120b adjacent to the side 120a to which the seismic isolation members 10C are fixed, and also oriented in a direction orthogonal to the side 120b, by which one end 11 is fixed to the upper face of the first coupling plate 120 via the bolt 40. Further, these two seismic isolation members 10D are placed at equal intervals along a side 130b adjacent to the side 130a to which the seismic isolation members 10C are fixed, and also oriented in a direction orthogonal to the side 130b, by which the other end 12 is fixed to the lower face of the second coupling plate 130 via the bolt 40.
Of eight seismic isolation members 10, two other seismic isolation members 10E different from the above other members are placed at equal intervals along a side 120c adjacent to the side 120b to which the seismic isolation members 10D are fixed, and also oriented in a direction orthogonal to the side 120c, by which one end 11 is fixed to the upper face of the first coupling plate 120 via the bolt 40. Further, these two seismic isolation members 10E are placed at equal intervals along a side 130c adjacent to the side 130b to which the seismic isolation members 10D are fixed, and also oriented in a direction orthogonal to the side 130c, by which the other end 12 is fixed to the lower face of the second coupling plate 130 via the bolt 40.
Of eight seismic isolation members 10, the remaining two seismic isolation members 10F are placed at equal intervals along a side 120d adjacent to the side 120c to which the seismic isolation members 10E are fixed, and also oriented in a direction orthogonal to the side 120d, by which one end 11 is fixed to the upper face of the first coupling plate 120 via the bolt 40. Further, these two seismic isolation members 10F are placed at equal intervals along a side 130d adjacent to the side 130c to which the seismic isolation members 10E are fixed, and also oriented in a direction orthogonal to the side 130d, by which the other end 12 is fixed to the lower face of the second coupling plate 130 via the bolt 40.
These two seismic isolation members 10C and the other two seismic isolation members 10E are fixed to the first coupling plate 120 and the second coupling plate 130. The seismic isolation members 10C are arranged so that curved portions of the seismic isolation members 10C are projected from between the first coupling plate 120 and the second coupling plate 130 in a direction (that is, in a positive direction indicated by the two-headed arrow X in
Further, these two seismic isolation members 10D and the other two seismic isolation members 10F are also fixed to the first coupling plate 120 and the second coupling plate 130. The seismic isolation members 10D are arranged so that curved portions of the seismic isolation members 10D are projected from between the first coupling plate 120 and the second coupling plate 130 in a direction (that is, in a positive direction indicated by the two-headed arrow Y in
The first coupling plate 120 and the second coupling plate 130 are placed in such a manner that all four sides are in alignment with each other when viewed from above.
According to the seismic isolation apparatus 101, a direction in which vibrations are incoming is assumed previously, and the seismic isolation members 10 are placed so as to be set along the assumed two directions (the direction indicated by the two-headed arrow X and the direction indicated by the two-headed arrow Y in
Therefore, production efficiency of the seismic isolation apparatus 101 can be raised both at the design stage and at the manufacturing stage, thus resulting in a lower manufacturing cost of the seismic isolation apparatus 1.
A description has been so far given of preferred embodiments of the present invention, to which the present invention shall not be, however, limited. The present invention may be subjected to addition, omission and replacement of the constitution and other modifications within a scope not departing from the gist of the present invention. The present invention shall not be limited by the above description but will be limited only by the scope of the attached claims.
For example, in the above embodiment, the seismic isolation apparatus is disposed on the lower section and then fixed to the lower section. Subsequently, the upper section is disposed on the seismic isolation apparatus, and the seismic isolation apparatus is fixed to the upper section. However, the method for installing the seismic isolation apparatus of the present invention may only include a step of disposing the seismic isolation apparatus on the lower section so that the seismic isolation members are set along a previously assumed direction of vibrations of the upper section to the lower section, a step of fixing the seismic isolation apparatus to the lower section, a step of disposing the upper section on the seismic isolation apparatus, and a step of fixing the seismic isolation apparatus to the upper section. Thus, the order of executing each of the above steps shall not be limited to the above-described order.
Further, the seismic isolation apparatus of the present invention is not only placed between a foundation (a lower section) and a building frame (an upper section) in structures such as buildings, bridges, elevated roads and elevated railways but also may be placed between members which constitute the above structures. The seismic isolation apparatus may be placed, for example, between a floor slab constituting a building and a deck slab placed on the floor slab. In this example, the seismic isolation apparatus absorbs the energy acting on the deck slab, instead of the energy acting on the building frame of the structure. Similarly, it may also be placed between a bridge pier constituting a bridge and a bridge girder placed on the bridge pier.
INDUSTRIAL APPLICABILITYThe present invention relates to a seismic isolation apparatus for damping vibrations of an upper section of a structure with respect to a lower section of the structure including a plurality of U-shaped seismic isolation members, a first coupling plate to which one end of the seismic isolation member is fixed, and a second coupling plate to which the other end of the seismic isolation member is fixed. Some of the seismic isolation members are placed between the first coupling plate and the second coupling plate in a predetermined direction. The other of the seismic isolation members are placed between the first coupling plate and the second coupling plate in a direction opposed to the predetermined direction.
According to the present invention, production efficiency of the seismic isolation apparatus can be raised both at the design stage and at the manufacturing stage, thus resulting in a lower manufacturing cost of the seismic isolation apparatus.
Claims
1. A seismic isolation apparatus for damping vibrations of an upper section of a structure with respect to a lower section of the structure, the seismic isolation apparatus comprising:
- a plurality of U-shaped seismic isolation members;
- a first coupling plate to which one end of the seismic isolation member is fixed; and
- a second coupling plate to which the other end of the seismic isolation member is fixed, wherein
- some of the plurality of the seismic isolation members are placed between the first coupling plate and the second coupling plate in a predetermined direction, and the other of the plurality of the seismic isolation members are placed between the first coupling plate and the second coupling plate in a direction opposed to the predetermined direction.
2. The seismic isolation apparatus according to claim 1, wherein
- both ends of the seismic isolation member are fixed with bolts respectively to the first coupling plate and the second coupling plate.
3. The seismic isolation apparatus according to claim 2, wherein
- one bolt is disposed at a portion of fixing one end of the seismic isolation member to the first coupling plate, and the other bolt is disposed at a portion of fixing the other end of the seismic isolation member to the second coupling plate.
4. The seismic isolation apparatus according to claim 2, wherein
- a plurality of the bolts are disposed at a portion of fixing one end of the seismic isolation member to the first coupling plate, and the other bolts are disposed at a portion of fixing the other end of the seismic isolation member to the second coupling plate.
5. The seismic isolation apparatus according to claim 1, wherein
- both ends of the seismic isolation member are welded respectively to the first coupling plate and the second coupling plate.
6. The seismic isolation apparatus according to claim 1, wherein
- recesses into which one end or the other end of the seismic isolation member is fitted are formed respectively on the first coupling plate and the second coupling plate, and
- both ends of the seismic isolation member are fitted respectively into the recesses and thereafter fixed to the first coupling plate and the second coupling plate.
7. The seismic isolation apparatus according to claim 1, further comprising an isolator having metal plates and plate-shaped elastic bodies alternately stacked, wherein
- the isolator is placed between the upper section and the lower section.
8. A method for installing a seismic isolation apparatus on a lower section and an upper section of a structure, the seismic isolation apparatus having a first coupling plate to be fixed to the lower section, a second coupling plate to be fixed to the upper section opposing the lower section, and a plurality of seismic isolation members fixed respectively to the first coupling plate and the second coupling plate so as to be placed between the first coupling plate and the second coupling plate toward a predetermined direction and a direction opposing the predetermined direction, the method for installing the seismic isolation apparatus comprising the steps of:
- disposing the seismic isolation apparatus on the lower section so that the seismic isolation members are set along a previously assumed direction of vibrations of the upper section to the lower section;
- fixing the seismic isolation apparatus to the lower section;
- disposing the upper section on the seismic isolation apparatus; and
- fixing the seismic isolation apparatus to the upper section.
9. A seismic isolation member placed between an upper section and a lower section, thereby damping the vibrations of the upper section to the lower section which are generated in a previously assumed direction by its own plastic deformation, wherein
- the seismic isolation member being formed in a U shape and placed between the upper section and the lower section along the previously assumed direction of vibrations, one end of the seismic isolation member is fixed to the lower section and the other end of the seismic isolation member is fixed to the upper section.
Type: Application
Filed: Oct 22, 2008
Publication Date: Oct 7, 2010
Inventors: Kohji Nishimoto (Tokyo), Hiroaki Konishi (Tokyo), Atsushi Watanabe (Tokyo)
Application Number: 12/734,295
International Classification: E04H 9/02 (20060101); E04B 1/98 (20060101);