JP2868128B2 - Artificial ground for seismic isolation of low load structures - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an artificial ground, and more particularly, to an artificial ground suitable for supporting a low-load structure in seismic isolation.

(Prior Art) A seismic isolation support device for seismically isolating and supporting a relatively heavy structure such as an office building or a bridge is disclosed in
As disclosed in Japanese Patent No. 49609, it is constituted by an elastic support for supporting the structure so as to be displaceable in the horizontal direction and capable of returning, and an energy absorber for attenuating the horizontal movement of the structure.

In order to obtain good seismic isolation performance when supporting low-load structures such as single-family houses, multi-family houses, apartments, warehouses, substations, and factory buildings with such a structure, high-load structures must be used. It is necessary to lower the spring constant in the horizontal direction of the elastic support as compared with the case of supporting the elastic support.

(Problems to be Solved by the Invention) Therefore, when a low-load structure is seismically isolated and supported, conventionally, the cross-sectional area (spring constant) of the elastic support is changed without changing the height (allowable displacement position) of the elastic support. Since the height is reduced, the height of the elastic support increases with respect to the cross-sectional area, and there is a problem that the elastic support becomes very unstable in supporting the structure.

In addition, when supporting a low-load structure such as a general house with seismic isolation, it is necessary to dispose the elastic support at the place where the pillars of the house are arranged, so that the number of elastic supports and the like increases, Since the arrangement structure is complicated, there is a disadvantage in design and construction.

Furthermore, when supporting a low-load structure, the lower-load structure has a smaller mounting load on the structure to be seismically isolated than a higher-load structure such as an office building or a bridge. Where the influence of external force is large, the structure may vibrate due to the wind or may fall down when severe.

In order to solve such a problem, the present applicant has already applied for a seismic isolation support method for a low-load structure in Japanese Patent Application No. 63-293351.

In the earlier application, when supporting a low-load structure,
Providing an artificial ground having an area larger than the building area of the low load structure, and having a predetermined strength and weight, arranging the artificial ground on the ground, between the ground and the artificial ground, the artificial ground A means for supporting the artificial ground so that it can be displaced in the horizontal direction, a means for urging the artificial ground to return to the original position when the artificial ground is displaced in the horizontal direction, and a means for attenuating the horizontal movement of the artificial ground. A seismic isolation support means is provided, and a low-load structure is constructed on the artificial ground.

This application contains the specific configuration of the artificial ground in the earlier application, and the object of the present invention is to secure the strength, rigidity and weight in supporting the low-load structure on the artificial ground in seismic isolation. In addition, the thickness can be reduced, and it is possible to assemble it on site, which is advantageous in construction, and furthermore, the weight applied to the artificial ground and thus the seismic isolation support device is easily adjusted according to the load of the structure. It is an object of the present invention to provide an artificial ground for supporting a seismically isolated low-load structure.

(Means for Solving the Problems) The configuration of the present invention for achieving the above object will be described with reference to the drawings corresponding to the embodiments.

The present invention relates to an artificial ground 1 for supporting a low-load structure with seismic isolation support means, which is constituted by combining a plurality of prestressed concrete beams 3A and 3B, has at least one opening 9, and has The frame 3 supported by the earthquake support means 31 and the frame 3 so as to close the opening 9 of the frame 3
And a topping concrete layer 7 cast and fixed on the precast concrete plate 5 or on the precast concrete plate 5 and the frame 3. Is characterized by being formed with a contour larger than an architectural surface on the artificial ground of the low-load structure.

(Action) Artificial ground 1 is prestressed concrete beam 3A, 3
Since the frame 3 made of B is provided, its strength and rigidity can be easily given so as to withstand the load of a low-load structure installed at an arbitrary position on the artificial ground 1, and a beam made of prestressed concrete is also provided. 3A, 3B and the precast concrete plate 5 are heavier than the artificial ground made of steel.

Therefore, the location of the seismic isolation support means may be any location that can be supported via the frame 3 without being restrained under the column on the low load structure side, and the low load structure can be freely constructed on the artificial ground 1. This is advantageous in terms of design, and can be supported by a smaller number of seismic isolation support devices as compared with the conventional support method in which a seismic isolation support device is provided for each column.

Further, since the weight can be secured while suppressing the thickness of the artificial ground 1, the supporting load per one seismic isolation support device 31 can be increased, and therefore, stable seismic isolation support can be achieved.

In addition, since the weight of the artificial ground can be set to about twice as much as that of the low-load structure, the center of gravity of the structure can be kept low, which is advantageous in preventing the structure from being vibrated and fallen by external force such as wind. Becomes

Further, since the artificial ground 1 can be assembled on site, it is advantageous in transporting and assembling the artificial ground 1.

When the topping concrete layer 7 not only measures the integration of the frame 3 and the press-cast concrete plate 5 but also changes the weight of the artificial ground 1 in accordance with the weight of the low-load structure, It can be easily coped with only by changing the amount of concrete to be put in, and can be coped with on site.

(Example) Hereinafter, an artificial ground in the case of supporting a general house with seismic isolation will be described from the first example.

FIG. 1 is a plan view of the artificial ground with the topping concrete layer removed, and FIGS. 2 to 5 are each a view of FIG.
A sectional view corresponding to the line II-II, III-III, IV-IV, and VV is shown.

Reference numeral 1 denotes an artificial ground, and the artificial ground 1 is formed with an area larger than a building area on the artificial ground 1 of a house.

The artificial ground 1 comprises a rectangular frame 3, four precast concrete plates 5, and a topping concrete layer 7.

Frame 3 consists of two vertical beams 3A made of prestressed concrete and two horizontal beams made of prestressed concrete
3B is assembled and an opening 9 is formed inside the frame 3.

For example, as shown in FIG. 1, assembling the vertical beam 3A and the horizontal beam 3B, the concrete is poured into the side surfaces of the ends of the vertical beam 3A and the both end surfaces of the horizontal beam 3B, and concrete is poured. The joint is performed by applying a compressive force with the prestressed steel material 11 inserted through the entire length of the part and the cross beam 3B.

As shown in FIG. 5, a concave portion 13 having a depth corresponding to the thickness of the precast concrete plate 5 is formed in a portion facing the opening 9 in the vertical beam 3A.

As shown in FIGS. 2 and 3, thin portions 15 are formed on the vertical beam 3A and the horizontal beam 3B along the outer periphery of the frame 3.

The four precast concrete plates 5 are formed with a width of 1/4 between the horizontal beams 3B and a length corresponding to between the two concave portions 13, and both ends thereof are placed in the concave portions 13 and incorporated into the frame 3. By this incorporation, the horizontal movement of the precast concrete plate 5 is restricted by the concave portion 13 and the horizontal beam 3B, and the precast concrete plate 5 is fixed.

Incidentally, the structure for fixing the precast concrete plate 5 and the frame 3 is optional.
The precast concrete plate 5 may be placed thereon, and the protrusion projecting from the lower surface of the precast concrete plate 5 may be engaged with the edge of the opening 9.

Further, when the topping concrete layer 7 is provided as in this embodiment, the frame 3 and the precast concrete plate 5 are integrated by the topping concrete layer 7, so that the precast concrete plate 5 is simply placed on the frame 3. May be placed only.

The opening 9 is closed by incorporating the precast concrete plate 5 into the frame 3, and the depth of the recess 13 corresponds to the thickness of the precast concrete plate 5. The upper surface of the frame 3 is substantially coplanar.

The topping concrete layer 7 is formed by pouring concrete over the upper surface of the precast concrete plate 5 and the upper surface of the frame 3, and forms the frame 3 via a dowel or the like.
And the precast concrete plate 5 and the topping concrete layer 7 are integrally fixed, whereby the artificial ground 1 is obtained.

When supporting a house on the artificial ground 1,
Forms a ground G ₁ with a height lower than the ground surface G ₀ around the site,
Installation for fixing a plurality of basic 21 to the ground G _1.

In the embodiment, the foundations 21 are connected to each other by an underground beam 23, and reference numeral 25 in the figure denotes a split chestnut.

 Next, the seismic isolation support device 31 is installed on the foundation 21.

The seismic isolation support device 31 includes a resilient support 33 that supports the structure so that the structure can be displaced in the horizontal direction and urges the structure in a direction to return to the original position when the structure is displaced in the horizontal direction. And an energy absorber 35 that attenuates the horizontal movement of That is, in the embodiment, the elastic support 33 includes means for supporting the structure so as to be displaceable in the horizontal direction, and means for biasing the structure in the direction of returning to the original position when the structure is displaced in the horizontal direction. Also serves as.

The elastic support 33 is a laminated body formed by laminating a thin steel reinforcing plate and a thin rubber plate and integrally forming the laminated body.
37 is provided.

The energy absorber 35 is made of a lead cylinder and has an elastic support 33.
It is installed vertically inside.

The height of the artificial ground 1 although substantially coincide with the height of the ground surface G ₀ in the example, or is arbitrary height of artificial ground 1 is higher or lower than the ground surface G _0.

Then, a house is constructed on the artificial ground 1, and the house is made of any material such as wooden, steel frame, or reinforced concrete.

Incidentally, between the edge of the artificial ground 1 and the edge of the ground surface G ₀ is
A gap 39 that allows the artificial ground 1 to move in the horizontal direction is ensured, but this gap 39 may be covered by appropriate means.

In the first embodiment, the artificial ground 1 has a width of 8 m, a length of 10 m, a thickness of 65 cm, and a weight of 57 ton. Also, vertical beam
3A is 1.1m wide, 10m long, 55cm thick and weighs 10ton. Also, the width of the horizontal beam 3B is 1.3 m, the length is 5.2 m, the thickness is
It is 55cm and weighs 5ton. The width of the precast concrete plate 5 is 2m, the length is 5m, the thickness is 3cm, and the weight is 1.5to.
n. Furthermore, the topping concrete layer 7 is 8
m, length 10m, thickness 10cm, weight 19ton.

According to the artificial ground 1 according to the present embodiment, since the frame 3 composed of the prestressed concrete beams 3A and 3B is provided, the artificial ground 1 has excellent strength and rigidity, and the prestressed concrete beams 3A and 3B and the precast The concrete plate 5 is heavy.

Therefore, the location of the elastic support 33 can be located at any location without being restrained under the column of the low-load structure, and the low-load structure can be freely constructed at a desired location on the artificial ground 1. This is advantageous in terms of design, and the structure can be easily extended or modified. In addition, it becomes possible to support with less seismic isolation support devices than the conventional support method in which the seismic isolation support devices are arranged for each column.

In addition, the prestressed concrete beams 3A and 3B, the precast concrete plate 5 and the topping concrete layer 7 are heavier than the artificial ground made of steel, and secure the weight while suppressing the thickness t (see FIG. 4) of the artificial ground 1. Therefore, the supporting load per seismic isolation support device can be increased, and stable seismic isolation support can be achieved.

The weight of the artificial ground 1 is about 2 to the low-load structure.
Since it has about twice, the center of gravity of the structure can be kept low, which is advantageous in preventing vibration or falling due to external force such as wind.

In addition, since the weight of the topping concrete layer 7 can be set larger by increasing the amount of the topping concrete layer 7 than that of the prestressed concrete beams 3A and 3B and the precast concrete plate 5, for example, the artificial ground 1 In the case of changing the weight, etc., it can be easily handled only by changing the thickness of the topping concrete layer 7,
Further, the topping concrete layer 7 can be directly used as a support base for the floor material of the house.

Further, as in the embodiment, when the precast concrete plate 5 is provided through the concave portion 13 and the upper surface of the frame 3 and the upper surface of the precast concrete plate 5 are coplanar, the thickness of the artificial ground 1 can be further suppressed. It becomes possible.

Also, by removing one of the four precast concrete plates 5 or forming an opening in the precast concrete plate 5 in advance, the artificial ground
41 It is easy to construct a passage to the basement or parking lot below.

Further, as the embodiment, when forming the thin portion 15 to the frame body 3 portion supported by an elastic support 33, it is possible to reduce the height of the artificial ground 1 from the ground G _1, seismic isolation support on, It is more advantageous.

Furthermore, since the frame 3 is composed of two vertical beams 3A and two horizontal beams 3B and can be assembled on site and the topping concrete layer 7 can be formed on site, the artificial ground 1 can be assembled on site. Therefore, as compared with the case where the completed artificial ground 1 is carried into the site, the artificial ground 1 can be easily transported, and it is advantageous in assembling to the seismic isolation support device 31 and advantageous in construction.

Further, the anchor for fixing the structural foundation can be easily buried and fixed in the topping concrete layer 7 in advance.

Further, since the artificial ground 1 is made of concrete, it does not require rust prevention treatment such as repainting as compared with the artificial ground made of steel, and therefore, the artificial ground 1 having low cost and excellent durability can be obtained.

Next, a second embodiment will be described with reference to FIGS. 6 and 7. FIG.

FIG. 6 is a plan view of the artificial ground with the topping concrete layer removed, and FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG.

The artificial ground 41 includes a rectangular frame 43, a precast concrete plate 45, and a topping concrete layer 47.

The frame body 43 has two vertical beams 43A, one intermediate beam 43C parallel to the vertical beams 43A at an intermediate portion between both vertical beams 43A, and a vertical beam 43A.
Four lateral beams 43 connecting the end of A and the end of intermediate beam 43C
B is formed, and two openings 49 are formed on both sides of the intermediate beam 43C. The number and arrangement structure of such intermediate beams 43C are arbitrary. For example, two intermediate beams 43C may be arranged to cross each other in a cross shape.

Each beam 43A, 43B, 43C is made of prestressed concrete, and assembling of vertical beam 43A, horizontal beam 43B and intermediate beam 43C,
For example, as shown in FIG.
A joint is made at each side surface of the end of 3C and both end surfaces of the horizontal beam 43B, and concrete is poured into the joint, and compressed by the prestressed steel material 11 inserted into the end of the two vertical beams 43A, the end of the intermediate beam 43C, and the horizontal beam 43B. It is performed by a method such as joining while applying force.

Further, a thin portion 55 is formed in a portion along the outer periphery of the frame body 43 as in the first embodiment.

Further, eight precast concrete plates 45 are placed on the frame 42 so as to close each opening 49, and concrete is poured on the upper surface of the precast concrete plate 45 and the upper surface of the frame 43 to form the topping concrete layer 7. Is formed, and the frame 43, the precast concrete plate 45, and the topping concrete layer 47 are integrally fixed via a dowel or the like, whereby the artificial ground 41 is obtained.

Then, the artificial ground 41 is supported by the seismic isolation support devices 31 disposed at both ends of the vertical beam 43A and both ends of the intermediate beam 43C, respectively.

In this second embodiment, the size of the artificial ground 41 is 14 m in width,
It is 10m long, 65cm thick and weighs 100ton. Also, the width of the vertical beam 43A is 1.1 m, the length is 10 m, the thickness is 55 cm, and the weight is 10
ton. Also, the width of the horizontal beam 43B is 1.3 m, the length is 5.2 m,
The thickness is 55cm and the weight is 5ton. The width of the intermediate beam 43C is 1 m, the length is 10 m, the thickness is 55 cm, and the weight is 12 ton.
The precast concrete plate 45 is 2m wide and 5m long.
m, thickness 3cm, weight 1.5ton. Further, the topping concrete layer 47 is 14 m wide, 10 m long, 10 cm thick, and weighs 34 ton.

Further, the number of the precast concrete plates 5, 45 may be one, and the shape of the artificial ground 1, 41 is rectangular in plan view in the embodiment, but can be formed in an arbitrary shape corresponding to the site shape.

(Effects of the Invention) As is clear from the above description, according to the artificial ground according to the present invention, the thickness can be reduced while ensuring strength and rigidity, and the weight can be easily adjusted. The artificial ground for seismic isolation support of a low-load structure that can be assembled on site and is advantageous for seismic isolation support and construction is obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of the artificial ground according to the first embodiment with the topping concrete layer removed, and FIGS. 2 to 5 are II-II, III-III, and IV-IV of FIG. 1, respectively. Line, V-
6 is a plan view of the artificial ground according to the second embodiment with the topping concrete layer removed, and FIG. 7 is a cross-sectional view corresponding to the line VII-VII of FIG. In the figure, 1,41 is artificial ground, 3,43 is a frame, 5,45 is a precast concrete plate, 7,47 is a topping concrete layer,
9 and 49 are openings, and 31 is a seismic isolation support device.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kyozo Fukasawa 1-34-34 Konan, Minato-ku, Tokyo Within the Central Technical Research Institute of the Japan Construction Management Association (72) Inventor Eiji Ikeda 3 Marunouchi, Chiyoda-ku, Tokyo No.4-1, PS Concrete Co., Ltd. (72) Inventor Mitsuo Hayashi 3-4-1, Marunouchi, Chiyoda-ku, Tokyo Within PS Concrete Co., Ltd. (72) Inventor Hiroshi Tada Fujisawa, Kanagawa Prefecture No. 8 in Kirihara-cho Oiles Industry Co., Ltd. (72) Inventor Ikuo Shimoda No. 8 in Kirihara-cho, Fujisawa City, Kanagawa Prefecture Inside Oiles Industry Co., Ltd. (56) References JP 1-2247665 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) E04H 9/02

Claims (4)

(57) [Claims] An artificial ground for supporting a low-load structure with seismic isolation support means, comprising a plurality of prestressed concrete beams in combination, having at least one opening, A frame supported by the means, a precast concrete plate placed on the frame so as to close the opening of the frame, and on the precast concrete plate, or on the precast concrete plate and the frame And a topping concrete layer that is cast and fixed, wherein the outline of the frame is formed with an outline larger than an architectural surface on the artificial ground of the low-load structure, Seismic isolation support artificial ground. 2. The artificial ground for supporting a seismic isolation of a low-load structure according to claim 1, wherein a plurality of said precast concrete plates are mounted. 3. The artificial ground for supporting a seismic isolation of a low-load structure according to claim 1, wherein an intermediate beam is provided laterally across the opening in the frame. 4. The artificial ground for seismic isolation support of a low-load structure according to claim 1, wherein a frame portion supported by said seismic isolation support means is formed in a thin portion.