JP2009281073A - Aseismatic foundation structure of building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foundation structure of a building, attaining high earthquake resistance to horizontal sway in an inexpensive and simple structure in a building constructed on a continuous footing. <P>SOLUTION: A groove 4 having a width longer than the lateral width of the continuous footing 1 is excavated on the ground 3 to install the continuous footing 1, cobblestone 5a-gravel is fed to the lower part of the groove and pressurized to form a lower cobblestone layer 5, a mat 6 formed by filling a net 6b having a mesh of 1.5 mm with gravel and sand of 25 mm or less is laid thereon, the upside of the mat is filled with cobblestone-gravel with space left on the right and left of the groove 4 to form an upper cobblestone layer 7, the continuous footing 1 is placed on the upper cobblestone layer, and the right and left spaces between the upper cobblestone layer and the continuous footing are filled with gravel-sand. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a foundation structure that enhances seismic strength against horizontal shaking of a wooden, steel frame, or concrete building in which a building is constructed on a concrete fabric foundation. It is a technology that increases earthquake resistance, which is particularly useful for wooden buildings.

  As is known in Japanese Patent Application Laid-Open No. 2006-274746, a current wooden building is first made by digging a groove in the ground, putting a chestnut into the lower part of the groove, and then making a reverse T-shaped cross section on it. A fabric foundation is placed, and the left and right groove spaces of the remaining fabric foundation are filled with soil, and a foundation, pillar, beam, and roof using wooden members are constructed on this fabric foundation.

  The weight of the wooden building is applied to the fabric foundation through beams, columns, foundations, etc. The load received by the fabric foundation is supported by the ground via Kuriishi.

However, when a strong roll earthquake occurs on the ground of this wooden building, the ground will slip sideways and move horizontally (displacement), and the fabric foundation and chestnut are firmly fixed to the ground in the horizontal direction. Therefore, the fabric foundation swings left and right as the ground moves horizontally (moves left and right). On the other hand, the building above the heavy fabric foundation tries to maintain its horizontal position due to inertia, the relative horizontal positional relationship between the building and the fabric foundation changes, the building tilts and collapses, or receives deformation and sits down. It was something that would give rise to bending. For this reason, wooden buildings constructed with cloth foundations have low earthquake resistance.
JP 2006-274746 A

  The problem to be solved by the present invention is to solve these conventional problems and to provide a seismic foundation for buildings using a fabric foundation that can obtain high seismic resistance against horizontal shaking with a simple structure at low cost. To provide a structure.

The configuration of the present invention that solves this problem is as follows.
1) Seismic foundation structure of a building constructed on a concrete cloth foundation, with a groove width longer than the width of the cloth foundation along the installation direction of the cloth foundation on the ground where the concrete cloth foundation is installed A lower chestnut rock layer is formed by filling the inner lower part of the groove with a chestnut stone layer, and gravel or sand or a mixture of gravel and sand is not leaked on the top surface of the bottom chestnut stone layer and is not easily damaged. A mat that is filled and sealed in a flexible rectangular parallelepiped mesh is laid, and a predetermined amount of chestnut is filled on the mat to leave the required space on both the left and right sides, forming an upper chestnut layer, and the bottom is A fabric foundation with an inverted T-shaped cross section that is widened in the transverse direction is provided on the upper Kuriishi layer, and gravel or sand or gravel and sand are placed in the left and right spaces between the upper Kuriishi layer and the fabric foundation and the groove inner surface. Filled with mixed material, and the top of the filled gravel and sand was open to the ground surface. Seismic foundation structure of building 2) Seismic foundation structure 3 of building according to 1), wherein the lower chestnut layer has a thickness of 10-30 cm, the mat has a thickness of 10-30 cm, and the upper chestnut layer has a thickness of 10-30 cm ) The building according to 1) or 2), wherein a plurality of spacing-holding wires for connecting the upper and lower or left and right opposing surfaces of the rectangular parallelepiped net are attached to prevent the outer shape of the net from being largely collapsed. Seismic foundation 4) Sealing a mixture of gravel and sand in the mat body, and the maximum length of the gravel is 40mm or less, in which gravel and sand of various particle sizes are mixed The seismic foundation structure of a building according to any one of 1) to 3) above, wherein the gravel and sand having a maximum length of 25 mm or less are 90 weight of the total amount of gravel and sand sealed in a net. % Of the seismic foundation of the building described in 4) above is there.

  According to the present invention, the gravel / sand sealed in the mesh body of the mat and the gravel / sand filled in the left and right spaces between the upper chestnut layer / cloth foundation and the groove inner surface on the mat and the friction of the ground and the horizontal・ Up / down shaking energy is absorbed, and the horizontal and vertical shaking of the fabric foundation is greatly suppressed, thus ensuring high earthquake resistance of the building.

  According to the present invention, when a lateral movement (left and right roll) occurs on the ground due to an earthquake, the lower chestnut layer integrated with the ground moves horizontally (left and right) together with the ground. On the other hand, the fabric foundation on which the building is loaded and the upper Kuriishi layer below it try to maintain the stationary state as it is due to the inertia of the weight of the building. Therefore, gravel or sand in the mat located between the lower and upper chestnut layers moves horizontally (left and right) together with the ground with the lower surface portion in contact with the lower chestnut layer meshing with the lower chestnut layer. The upper surface of the mat engages with the upper chestnut layer to maintain a static state. And the gravel and sand in the middle of the mat will be in the middle horizontal (left and right) movement under the action of the stationary and horizontal left and right movements of the upper and lower surfaces. Gravel and sand in the mat are transmitted horizontal and vertical movements from the chestnuts in the lower chestnut layer, transferring the horizontal movement energy and vertical movement energy upward and downward while moving and rolling. . In the meantime, the gravel and sand move while rubbing each other, and the energy is consumed and attenuated by the motion and friction and transmitted upward. As a result, the amplitude of horizontal (left and right) movement of gravel and sand in the middle of the mat gradually decreases as it goes upward. And the gravel and sand on the top surface of the mat move only very small, and the horizontal movement of the upper chestnut layer, fabric foundation and the building above it can be very small. For this reason, the building has only a weak horizontal movement, approaches a stationary state, and the building does not deform or tilt.

  Also, even if the mat is pressed (pressed) from the side of the groove by horizontal movement of the ground and depressurized away from the other side of the groove, the gravel and sand in the mat will be restrained in the mesh body and will not flow out, and will fill the interior. Since the gravel and sand can flow and roll inside, the pressed gravel and sand move to the other decompression side to maintain a uniform filling state, and the upper chestnut layer and fabric foundation tilt from the horizontal. It will never happen.

  In addition, there is gravel and sand in the left and right spaces between the upper Kuriishi layer / cloth foundation and the inner surface of the groove, and even if the groove moves horizontally (left / right) with the ground, it is intermediate between the upper Kuriishi layer and the fabric foundation. The gravel / sand is pressurized or depressurized, and the gravel / sand on the pressurized side moves toward the open upper surface. On the other hand, the gravel / sand on the side whose upper surface is opened moves to the lower decompression region on the side to be decompressed, and the gravel / sand filling state is maintained.

  In this way, the gravel and sand part in contact with the fabric foundation and upper Kuriishi layer are close to the stationary state together with the fabric foundation and upper Kuriishi layer, while the gravel and sand part in contact with the lower Kuriishi layer and groove inner wall are the ground (groove) The gravel and sand between them move in the middle, right and left, and up and down. Energy is also consumed by gravel / sand friction and gravel / sand movement, greatly reducing the transmission of ground shaking energy to the fabric foundation / building.

The gravel and sand in this mat and the gravel and sand in the left and right spaces above it form a boundary layer between the ground side (grooves and lower chestnuts) and the building side (cloth foundation and upper chestnuts).・ Do not transmit the up and down vibrations directly to the fabric foundation, but make it damped. In the boundary layer, it is converted into frictional energy and kinetic energy by gravel and sand movement and rolling, and energy is consumed.
Therefore, the horizontal and vertical shaking of the ground is not transmitted to the building side, the inertial state of the building on the fabric foundation is maintained, the shaking, deformation, and tilting are few, and high earthquake resistance can be obtained.

As gravel / sand to be filled in the mesh body of the mat of the present invention and gravel / sand to be filled in the left and right spaces in the groove on the mat, those having dimensions and shapes that are easy to move are used, but the maximum length is 40 mm or less. Preferably, gravel and sand of 25 mm or less are used, and those of 25 mm or less are 90% by weight or more of the total amount of gravel and sand. A mixture of gravel and sand having various lengths and particle sizes equal to or smaller than the dimensions is more preferable because it increases the flow and rolling properties of gravel and sand. A gravel shape that is not square is preferable because it has good fluidity and rolling properties.
Gravel and sand are natural gravel and sand, or smooth gravel and sand made from them, or acrylic and other plastic gravel and sand that have excellent pressure resistance and little deterioration. Gravel / sand and fine ceramic gravel / sand can be used.

  As the material for the mat body of the present invention, a material that does not corrode, has high tensile strength, and is not easily damaged is used, but is mainly made of a net or iron woven with nylon, carbon fiber, or aramid fiber threads. The wire mesh is good. Further, it is preferable that the mesh body is connected to a plurality of places with the wire body such as a high-strength string or metal wire between the upper, lower, left and right sides of the mesh body so that the mesh body maintains a rectangular parallelepiped shape.

Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is an explanatory diagram illustrating a support structure of a fabric foundation as a main part of the first embodiment.
FIG. 2 is a perspective view of the net body according to the first embodiment.
FIG. 3 is an explanatory diagram illustrating the amplitude of gravel / sand movement according to the first embodiment.

  In the figure, 1 is a fabric foundation, 2 is an upper wooden building, 2a is a foundation on the fabric foundation, 2b is a pillar on the foundation, 3 is the ground, 4 is a groove having a depth of 60 cm and a groove width of 60 cm, 5 Is a lower chestnut layer with a thickness of 16 cm, 5a is a chestnut stone of the lower chestnut stone layer, and uses a chestnut stone and gravel with a size of about 10 cm. 6 is a mat with a thickness of 15 cm, 6a is a mixture of gravel with a maximum length of 25 mm and gravel and sand, and 95% by weight of sand. , 6b is a 600 mm × 500 mm × 150 mm rectangular mesh body made of wire mesh, 6c is a spacing wire provided between the upper and lower surfaces of the mesh body 6b, and 6d is stretched on the surface of the mesh body 6b. The reinforcing wire rod 7 is an upper chestnut layer having a left and right width of 46 cm and a thickness of 16 cm, and is filled with chestnut stone 7a and gravel having a size of about 10 cm. The cloth foundation 1 is made of concrete and has an inverted T-shaped cross section, and the lateral width of the left and right wide part of the lower part is 46 cm. Reference numeral 8 denotes gravel / sand filled between the side surface of the cloth foundation 1 and the upper chestnut layer 7 and the inner surface of the groove 4, and has the same configuration as the gravel / sand 6 a of the mat 6.

In Example 1, a chestnut stone 5a having a size of about 10 cm and gravel are placed under a groove 4 having a width of 60 cm and pressed from above to tighten, thereby forming a lower chestnut layer 5 having a thickness of 16 cm. The chestnut stones 5a are intertwined with each other to form a fixed support layer with the ground 3.
Next, within a rectangular parallelepiped wire net 6b of 600 mm (horizontal width) × 500 mm (horizontally long) × 150 mm (height), a maximum length of 25 mm or less is 95% by weight and a variety of less The mat 6 is formed by filling gravel / sand 6a in a mixed state of gravel / sand having a length / particle size to a thickness of 150 mm, and the mat is continuously laid on the lower chestnut layer 5. The mat is usually manufactured in a factory and transported to the site for use.

  Next, a vertical side mold plate (not shown) having a height of 30 cm is arranged at a position 70 mm away from each of the left and right inner surfaces of the groove 4 on the mat, and the size is about 10 cm in the left and right side mold plates. The chestnut stone 5a and gravel are filled, and the upper chestnut layer 7 having a thickness of 150 mm is formed by pressing and tightening from above. A pair of left and right upper mold plates (not shown) having an L-shaped cross section is installed at a position of 120 mm on the upper chestnut layer 7, and concrete is poured from above the space between the vertical plates of the pair of upper mold plates. Then, the fabric foundation 1 is placed on the upper Kuriishi layer 7 on site.

After the fabric foundation 1 is placed and solidified, the formwork is removed and gravel in the net 6b is placed in a space of about 70 mm on the left and right between the inner surface of the groove 4, the upper chestnut layer 7 and the side surface of the fabric foundation 1. Fill with gravel and sand 8 having the same structure as the sand 6a, pressurize from above and tighten.
The base 2a of the wooden building 2 is fixed on the cloth foundation 1, and the building 2 is constructed by assembling wooden building members such as pillars 2b, beams, and roofs thereon.

  In the foundation structure of the fabric foundation 1 formed in this way, the vertical shaking and the vertical load are applied to the ground 3 through the wooden building 2, the fabric foundation 1, the upper chestnut layer 7, the mat 6, and the lower chestnut layer 5. It is transmitted and the building load is supported. Further, the up and down vibrations are the gravel and sand 6a in the mat 6 rolling and moving to absorb energy, and the up and down vibrations are buffered.

  Next, for rolling of the ground surface 3, gravel / sand 6 a in the mat 6 in contact with the upper surface of the lower chestnut layer 5 and the lower surface of the groove 4 and gravel / sand in contact with the upper surface of the groove 4 above the mat 6. The portion 8 moves to the left and right as the ground 3 rolls (horizontal movement and left-right movement). On the other hand, the lower surface of the upper chestnut layer 7 in the mat 6 and the gravel and sand 8 in contact with the side surface of the fabric foundation 1 and the side surface of the upper chestnut layer 7 do not move so much to keep the stationary state due to the inertia of the building on the fabric foundation 1. . The state of the amplitude of this vibration is shown in FIG. Gravel / sand 6a, 8 in the middle of these is a boundary layer between them, and the horizontal and vertical shaking (vibration) has an intermediate value. The vibration energy of the ground is absorbed as gravel and sand 6a in the mat 6 and the gravel and sand 8 in the left and right spaces above the groove and the energy of free movement and friction. Is transmitted to. Similarly, the vertical shaking of the earthquake also causes the gravel and sand layer in the mat to act as a boundary layer for vertical vibration, and the vibration and kinetic energy are absorbed by the gravel and sand rolling and loosening to increase the shaking. Buffer.

  Therefore, the ground shaking of the fabric foundation 1 of the first embodiment is greatly buffered and transmitted, the horizontal and vertical shaking of the fabric foundation 1 is not so much, and the upper building is tilted or deformed. Can be largely avoided and has high earthquake resistance. The upper and lower chestnut layers, gravel and sand in the mat, and gravel and sand in the left and right spaces are also permeable and drainage is good.

  The present invention is effective not only for current wooden buildings using cloth foundations but also for factories, huts, and steel concrete structures constructed on cloth foundations.

It is explanatory drawing which shows the support structure of the fabric foundation of the principal part of Example 1. FIG. 1 is a perspective view of a net body of Example 1. FIG. It is explanatory drawing which shows the amplitude of the gravel and sand movement of Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cloth foundation 2 Wooden building 2a Base 2b Pillar 3 Ground 4 Groove 5 Lower chestnut stone layer 5a Kuriishi 6 Mat 6a Gravel / sand 6b Net body 6c Spacing wire 6d Reinforcement wire 7 Upper chestnut layer 7a Kuriishi 8 Sand

Claims (5)

  A seismic foundation structure of a building constructed on a concrete cloth foundation, with a groove width that is longer than the width of the cloth foundation along the direction of the cloth foundation on the ground where the concrete cloth foundation is installed. The bottom of the groove is filled with crushed stone to form a lower crushed stone layer, and gravel or sand or a mixture of gravel and sand is not leaked on the upper surface of the lower crushed stone layer and is not easily damaged. A mat that is filled and sealed in a rectangular parallelepiped mesh is laid and filled with a certain thickness of chestnut so as to leave the required space on the left and right sides of the mat, forming an upper chestnut layer, with the bottom in the horizontal direction A cloth foundation with an inverted T-shaped cross section widened on the upper Kuriishi layer, and gravel or sand or a mixture of gravel and sand in the left and right spaces between the upper Kuriishi layer and the cloth foundation and the groove inner surface The building has a structure where the top of the filled gravel and sand is open to the ground surface. Earthquake-resistant foundation structure.   The earthquake-resistant foundation structure of a building according to claim 1, wherein the lower chestnut layer has a thickness of 10 to 30 cm, the mat has a thickness of 10 to 30 cm, and the upper chestnut layer has a thickness of 10 to 30 cm.   The earthquake-resistant foundation of a building according to claim 1 or 2, wherein a plurality of spacing-holding wires for connecting the upper and lower or left and right opposing surfaces of a rectangular parallelepiped net are attached to prevent a major collapse of the outer shape of the net. Construction.   A mixture of gravel and sand is sealed in the mesh body of the mat, and the maximum length of the gravel is 40 mm or less, in which gravel and sand of various particle sizes are mixed, The earthquake-proof foundation structure of the building in any one of Claims 1-3.   The earthquake-resistant foundation structure of a building according to claim 4, wherein gravel and sand having a maximum length of 25 mm or less are 90% by weight or more of the total amount of gravel and sand sealed by the net.

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