JP2008002182A - Vibration damping mechanism for building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration damping mechanism simple in structure, high in workability and obtaining a superior vibration damping effect in spite of being relatively inexpensive. <P>SOLUTION: The vibration damping mechanism provided between a concrete foundation 1 and a steel foundation 2 in a building comprises anchor bolts 10 inserted in the concrete foundation 1; a base plate 20 provided at the lower end of the steel foundation 2 and having vibration damping anchor holes 20a sufficiently larger in diameter than the anchor bolts 10; and a sliding plate 11 for reducing frictional resistance of the base plate 20. The sliding plate 11 and the base plate 20 are sequentially installed in a layered state on the concrete foundation 1 by inserting anchor bolts 10 through the vibration damping anchor holes 20a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a seismic reduction mechanism for attenuating shaking of a building during an earthquake, particularly a direct earthquake.

There are various seismic reduction devices that attenuate the shaking of buildings during an earthquake. This seismic reduction device includes, for example, a ball bearing support and an oil damper between an upper structure and a lower structure (see Patent Document 1 and Patent Document 2). There is also a vibration damping device made of multi-stage laminated rubber in which rubber and steel plates are alternately laminated (see, for example, Patent Document 3). However, such a vibration damping device has a problem that the structure is complicated and expensive, and lacks versatility.
Furthermore, since the natural period of the building has little influence on a direct type earthquake having shocking characteristics, the above structure does not have a significant seismic reduction effect.
JP 2005-42222 A JP-A-9-221866 Japanese Patent Laid-Open No. 9-112064

  Therefore, in view of the circumstances described above, the present invention provides a seismic reduction mechanism for a building that has an excellent seismic reduction effect in a direct type earthquake despite having a simple structure, good workability, and relatively low cost. Is to provide.

  The seismic reduction mechanism for a building according to the present invention is a seismic reduction mechanism provided between a concrete foundation and a steel foundation in a building, and is provided at an anchor bolt planted on the concrete foundation and a lower end of the steel foundation. A base plate having a vibration-reducing anchor hole that is sufficiently larger than the diameter of the anchor bolt, and a sliding plate that reduces the frictional resistance of the base plate. An anchor bolt is inserted through the anchor hole and installed in a laminated form.

  Preferably, a washer having an anchor hole having substantially the same diameter as the anchor bolt is provided, and the washer is fixed to the base plate by inserting the anchor bolt into the anchor hole.

  Preferably, at least one shock absorbing plate having an anchor hole having substantially the same diameter as the anchor bolt is provided, and the shock absorbing plate is fixed to the base plate by inserting the anchor bolt into the anchor hole.

  More preferably, the vibration-reducing member is provided in a gap portion formed between each anchor bolt and each vibration-reducing anchor hole.

  As described above, the vibration-reducing mechanism according to the present invention basically has a structure in which the sliding plate and the base plate are arranged in a laminated manner on the upper surface of the concrete foundation, so that it is very simple, workability and production. Rich in nature. Although it has a simple configuration, the base plate has a vibration-reducing anchor hole that is sufficiently large in diameter relative to the anchor bolt, so that the anchor bolt moves and collides with the interior of the vibration-reducing anchor hole during an earthquake. Thus, it is possible to effectively reduce the vibration of the building through the steel foundation.

  Furthermore, by fixing the shock absorbing plate to the base plate by inserting the anchor bolt into the anchor hole, the anchor bolt collides with the anchor hole and tries to widen the anchor hole at the time of an earthquake. Because it absorbs, the seismic reduction effect can be improved.

  Embodiments of a building vibration reduction mechanism according to the present invention will be described below in detail with reference to the accompanying drawings.

First embodiment

  1A and 1B are perspective views showing a seismic reduction mechanism of the entire building, in which FIG. 1A shows a state before the steel foundation is installed on the concrete foundation, and FIG. 1B shows a state where the steel foundation is installed on the concrete foundation. FIG. 2 is an enlarged view of the vibration reducing mechanism of the first embodiment, where (a) is a perspective view and (b) is a cross-sectional side view.

  As shown in FIG. 1A, a plurality of anchor bolts 10 are planted on the upper surface of the concrete foundation 1. The diameter, number, arrangement, and the like of the anchor bolt 10 are determined according to the weight of the building, the design standard, and the like. A plurality of base plates 20 are provided at the lower end of the steel foundation 2. A wooden base is placed on the steel foundation 2, and a floor portion, a wall portion, and the like are constructed. As shown in FIG. 1B, when the steel foundation 2 is placed on the concrete foundation 1, the anchor bolt 10 and the base plate 20 are connected.

  As shown in FIG. 2, a metal sliding plate 11 is provided on the upper surface of the concrete foundation 1. The sliding plate 11 made of metal or the like is provided at a position where the base plate 20 of the steel foundation 2 is placed on the upper surface of the concrete foundation 1. The sliding plate 11 reduces the frictional resistance of the base plate 20 and makes it easier for the steel foundation 2 to slide to the concrete foundation 1 during an earthquake. The base plate 20 includes a vibration reducing anchor hole 20a. The vibration-reducing anchor hole 20 a has a sufficiently large diameter (for example, 10 to 20 times) with respect to the anchor bolt 10. The vibration-reducing anchor hole 20a is at a position where the anchor bolt 10 is inserted.

  The base plate 20 includes fixing bolts 20b and 20b on both sides of the vibration reducing anchor hole 20a. A triple band washer 25 is provided on the base plate 20. The triple washer 25 has an anchor hole 25a at the center and bolt holes 25b and 25b on both sides thereof. The anchor hole 25a has substantially the same diameter as the anchor bolt 10, and the bolt holes 25b and 25b have substantially the same diameter as the fixing bolts 20b and 20b. The anchor bolt 10 is inserted into the anchor hole 25a, the fixing bolts 20b and 20b are inserted into the bolt holes 25b and 25b, and the triple washer 25 is placed on the base plate 20. In this state, the anchor nut 26 a is screwed to the anchor bolt 10, and the fixing nuts 26 b and 26 b are screwed to the fixing bolts 20 b and 20 b to fix the triple band washer 25 to the base plate 20.

  As shown in FIG. 2B, a gap portion 10a is formed between the anchor bolt 10 and the vibration reducing anchor hole 20a. The upper part of the anchor bolt 10 moves following the left-right movement of the base plate 20 by being fixed by the triple band washer 25. During an earthquake, the base plate 20 moves left and right by a predetermined distance by the gap 10a. Then, the upper part of the anchor bolt 10 moves left and right, and the anchor bolt 10 tilts and moves the gap portion 10a left and right, so that the base plate 20 moves by the tilt amount. When the vibration reducing anchor hole 20a is not so large, the anchor bolt 10 collides with the vibration reducing anchor hole 20a, and the vibration of the base plate 20 is suppressed.

  Moreover, the vibration reducing member 10b which fits the gap portion 10a is provided. The vibration-reducing member 10b only needs to have an impact absorption capability, and may be configured by, for example, filling the gap member 10a with sand or the like outside a rubber or urethane ring member. Thereby, the vibration-reducing member 10b becomes a cushion by the left-right inclined movement of the anchor bolt 10, and the impact can be suppressed and vibration can be reduced slowly.

Second embodiment

  Next, the vibration reducing mechanism of the second embodiment will be described. FIG. 3 is an enlarged view of the vibration reducing mechanism of the second embodiment, where (a) is a perspective view and (b) is a cross-sectional side view. In addition, about 2nd embodiment, a different part from said 1st embodiment is demonstrated in detail.

  As shown in FIG. 3, the vibration reduction mechanism of the second embodiment has substantially the same configuration as the vibration reduction mechanism of the first embodiment. In this embodiment, an impact absorbing plate 21 made of a relatively thin metal (in this embodiment, a lead plate having a thickness of 1 mm) is provided on the base plate 20. The thickness, number, material, and the like of the shock absorbing plate 21 are changed according to the structure of the building, the design earthquake, and the like. The shock absorbing plate 21 may be made of, for example, a reinforcing fiber material. The shock absorbing plate 21 is provided with an anchor hole 21a in the center and bolt holes 21b and 21b on both sides thereof. The anchor hole 21a has substantially the same diameter as the anchor bolt 10, and the bolt holes 21b and 21b have substantially the same diameter as the fixing bolts 20b and 20b. The anchor bolt 10 is inserted into the anchor hole 21a, the fixing bolts 20b and 20b are inserted into the bolt holes 21b and 21b, and the shock absorbing plate 21 is placed on the base plate 20.

  Then, two washers 25 'and 25' are prepared. Washers 25 'and 25' are provided with bolt holes 25b and 25b. The bolt holes 25b and 25b have substantially the same diameter as the fixing bolts 20b and 20b. On the shock absorbing plate 21, the fixing bolts 20b and 20b are inserted into the bolt holes 25b and 25b, and the washers 25 'and 25' are placed. In this state, the anchor nut 26 a is screwed to the anchor bolt 10, and the fixing nuts 26 b and 26 b are screwed to the fixing bolts 20 b and 20 b to fix the shock absorbing plate 21 to the base plate 20.

  As shown in FIG. 3B, the periphery of the anchor bolt 10 is covered with an anchor hole 21 a of the shock absorbing plate 21. Therefore, at the time of an earthquake, the anchor bolt 10 is inclined to the left and right by the gap portion 10a, and tries to deform and widen the anchor hole 21a of the shock absorbing plate 21. Thus, when the anchor bolt 10 collides with the shock absorbing plate 21, the shock of the steel frame 2 is absorbed and the vibration is reduced.

  In the vibration-reduction mechanism according to this embodiment, the triple washer 25 of the above-described embodiment may be used instead of the washers 25 'and 25'.

Experimental example

  Next, with respect to the vibration reducing mechanism in the first and second embodiments described above, the following method is used for experiments to clarify the effects. FIG. 4 is a configuration diagram for explaining the experimental method.

[experimental method]
As shown in FIG. 4 (a), a carriage 30 is used in this experimental method. The carriage 30 travels along the rail 31. On the carriage 30, a vibration reducing mechanism according to the present invention which is an object of experiment is provided. Accordingly, the concrete foundation 1 is laid on the carriage 30, and the steel foundation 2, the base plate 20, and the like are installed on the concrete foundation 1. Further, a wooden frame 36 that is a model of a building is provided on the steel frame foundation 2. The weight of the wooden frame 36 is adjusted to about 500 kg with an iron plate or the like.

  One end of a traction wire 32 is connected to the front portion of the carriage 30. A weight 35 is connected to the other end of the pulling wire 32. The rail 31 is provided with a drop table 34. The pulling wire 32 hangs downward through the upper end of the drop table 34 via a pulley. The weight 35 has a weight of about 450 kg. Therefore, the carriage 30 is pulled forward by the weight 35 and the pulling wire 32. In the stage before the experiment, the rear portion of the carriage 30 is connected to the rail 31 via the wire 33. Thereby, the trolley | bogie 30 has stopped in the state pulled by the front.

  Then, the wire 33 is cut simultaneously with the start of the experiment. Thereby, the carriage 30 is pulled forward by the weight 35 and the pulling wire 32 and travels along the rail 31. Then, the weight 35 falls freely, and the carriage 30 travels at an accelerated speed. Thereafter, after the weight 35 has landed on the ground, the carriage 30 travels at a constant speed over a certain distance (250 mm in this experiment). Then, the projecting cart stopper 30a provided on the lower surface of the base 30 collides with the projecting rail stopper 31a provided on the upper surface of the rail 31, and the cart 30 stops suddenly. Thereby, an impact force based on an inertial force is generated in the carriage 30, and the same impact force as that at the time of an earthquake can be transmitted to the concrete foundation 1. As shown in FIG. 4, the impact accelerometer AC is attached to the wooden frame 36. With this impact accelerometer AC, the impact force of the wooden frame 36 (building) at the time of the earthquake was measured.

[Experimental result]
FIG. 5 is a graph of experimental results in which the horizontal axis represents time (sec) and the vertical axis represents acceleration (m / s ² ). The graph line G1 shows the experimental results employing the above-described vibration reduction mechanism of the first embodiment. A graph line G2 shows an experimental result in which the vibration reducing mechanism of the second embodiment (three shock absorbing plates in this experiment) is used. Graph line G3 shows the experimental results in a form in which the seismic reduction mechanism is not employed and the concrete foundation 1 and the base plate 20 of the steel foundation 2 are completely connected.

  FIG. 6 is a photographic view showing the vibration reducing mechanism according to the first embodiment after the experiment. FIG. 7 is a photograph showing the seismic reduction mechanism according to the second embodiment after the experiment. From FIG. 6, it is clear that in the vibration reducing mechanism of the first embodiment, the vibration is reduced by tilting the anchor bolt. From FIG. 7, it is clear that in the vibration reducing mechanism of the second embodiment, the shock is absorbed by the shock absorbing plate and the vibration is reduced.

From the graph line G1 shown in FIG. 5, in the case of the vibration reducing mechanism of the first embodiment, the maximum value of the impact acceleration transmitted to the wooden frame 36 is about 16.8 (m / s ² ). From the graph line G2 shown in FIG. 5, in the case of the vibration reducing mechanism of the second embodiment, the maximum value of the impact acceleration transmitted to the wooden frame 36 is about 8.7 (m / s ² ). From the graph line G3 shown in FIG. 5, when there is no vibration reduction mechanism, the maximum value of the impact acceleration transmitted to the wooden frame 36 is about 40.9 (m / s ² ).

  From the above experimental results, the maximum shock acceleration of the vibration reduction mechanism according to the first embodiment is about 0.4 times the maximum shock acceleration without the vibration reduction mechanism, and the maximum shock acceleration of the vibration reduction mechanism according to the second embodiment. Is about 0.2 times, and it has been proved by experiments that all of them exert a great seismic reduction effect in direct type earthquakes.

It is a perspective view which shows the seismic reduction mechanism of the whole building, (a) is the state before installing a steel foundation on a concrete foundation, (b) shows the state which installed the steel foundation on the concrete foundation. The seismic-reduction mechanism of 1st embodiment is expanded and shown, (a) is a perspective view, (b) is a cross-sectional side view. The vibration-reduction mechanism of 2nd embodiment is expanded and shown, (a) is a perspective view, (b) is a cross-sectional side view. It is a block diagram for demonstrating an experimental method. It is a graph of an experimental result. It is a photograph figure which shows the earthquake-reduction mechanism which concerns on 1st embodiment after an experiment. It is a photograph figure which shows the seismic-reduction mechanism which concerns on 2nd embodiment after an experiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Concrete foundation 2 Steel foundation 10 Anchor bolt 10a Space | gap part 10b Anti-seismic member 11 Sliding plate 20 Base plate 20a Anti-vibration anchor hole 21 Shock absorbing plate 25 Washer 21a, 25a Anchor hole

Claims (4)

  An anti-seismic mechanism provided between a concrete foundation (1) and a steel foundation (2) in a building, the anchor bolt (10) planted on the concrete foundation (1), and the steel foundation (2 ), A base plate (20) having a vibration-reducing anchor hole (20a) having a diameter sufficiently larger than the diameter of the anchor bolt (10), and a sliding plate (reducing the frictional resistance of the base plate (20)) 11), and the sliding bolt (11) and the base plate (20) are sequentially inserted on the concrete foundation (1), and the anchor bolt (10) is inserted through the anchor hole for vibration reduction (20a). A seismic reduction mechanism for buildings, characterized by being installed in layers.   A washer (25) having an anchor hole (25a) having substantially the same diameter as the anchor bolt (10), the washer (25) being inserted through the anchor bolt (10) into the anchor hole (25a) The structure vibration-reducing mechanism according to claim 1, wherein the structure is fixed to the base plate (20).   At least one shock absorbing plate (21) having an anchor hole (21a) having substantially the same diameter as the anchor bolt (10) is provided, and the shock absorbing plate (21) is inserted into the anchor bolt (21a) with the anchor bolt (21a). The building vibration-reducing mechanism according to claim 1 or 2, wherein the structure is fixed to the base plate (20) through 10).   2. A vibration-reducing member (10b) provided in a gap portion (10a) formed between each anchor bolt (10) and each vibration-reducing anchor hole (20a). A vibration-reducing mechanism for a building according to any one of 3 to 3.