JP2012046979A - Building foundation using earth retaining wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent an end of a base from being destroyed by undergoing tensile force from an earth retaining wall, when external force directed in a direction orthogonal to the earth retaining wall acts on the earth retaining wall above the base having the end connected to the earth retaining wall.SOLUTION: A building foundation using an earth retaining wall provided in the ground includes: a base which is provided below a surface of the ground to be perpendicular to the earth retaining wall and has an end connected to the earth retaining wall; and a reinforcing member which comprises a first portion disposed in parallel with the earth retaining wall inside the end of the base and fixed to the end, and a second portion perpendicular to the first portion, horizontally elongated inward from the end and fixed to the base.

Description

  The present invention relates to a building foundation using a retaining wall provided in the ground.

  Conventionally, there are buildings that use retaining walls provided in the ground. The foundation has a bottom plate provided perpendicularly to the retaining wall below the surface of the ground, and the bottom plate has an end coupled to the retaining wall (see Patent Document 1).

JP 2003-147778 A

  The retaining wall above the bottom plate receives earth pressure and water pressure from the ground. At this time, the retaining wall is bent and deformed, and the end portion of the bottom plate receives a tensile force from the retaining wall. For this reason, when the said tensile force is remarkably large, there exists a possibility that the said edge part of the said bottom plate may be destroyed.

  An object of the present invention is to provide an end force of the bottom slab from the retaining wall when an external force in a direction perpendicular to the retaining wall is exerted on the retaining wall above the bottom slab having an end coupled to the retaining wall. It is to surely prevent them from being destroyed.

  The present invention includes a bottom plate having an end portion coupled to a retaining wall, a first portion disposed in parallel to the retaining wall inside the end portion of the bottom plate, and fixed to the end portion, and the first portion. And a reinforcing member having a second portion that extends vertically inward from the end portion and that is fixed to the bottom plate. Accordingly, when an external force in a direction orthogonal to the retaining wall above the bottom plate acts and the end portion of the bottom plate receives a tensile force from the retaining wall, the tensile force is applied to the reinforcing member. The second part is transmitted to the second part through the first part so that the second part resists the tensile force. This reliably prevents the end portion of the bottom slab from receiving the tensile force from the retaining wall and breaking.

  The foundation of the building using the retaining wall provided in the ground according to the present invention is a bottom slab provided perpendicularly to the retaining wall below the surface of the ground and coupled to the retaining wall. A bottom plate having an end portion, a first portion fixed to the end portion and parallel to the retaining wall inside the end portion of the bottom plate, and a second portion perpendicular to the first portion And a reinforcing member extending inwardly from the end portion in the horizontal direction and having a second portion fixed to the bottom plate.

  When an external force in a direction perpendicular to this acts on the retaining wall above the bottom plate, the retaining wall is bent and deformed, and the end portion of the bottom plate receives a tensile force from the retaining wall. The reinforcing member includes a first portion that is disposed in parallel to the retaining wall inside the end portion of the bottom plate, and is fixed to the end portion, and a second portion that is perpendicular to the first portion. And extending inwardly from the end portion in a horizontal direction and having a second portion fixed to the bottom plate, when the end portion of the bottom plate receives the tensile force from the earth retaining wall, the tensile force is The end portion of the bottom plate is transmitted to the second portion through the first portion of the reinforcing member, and the second portion resists the tensile force. Thereby, the said edge part of the said bottom slab can be reinforced and it can prevent that the said edge part of the said bottom slab receives the said tensile force from the said earth retaining wall, and destroys.

  The foundation includes a side wall provided parallel to the retaining wall on the end of the bottom slab and coupled to the retaining wall. Since the side wall is coupled to the retaining wall, a horizontal force acting on the sidewall during an earthquake can be reliably transmitted to the retaining wall, and the horizontal force can be borne on the retaining wall. Thereby, the load which the said side wall bears can be reduced, the said side wall can be made thin, and the foundation of a building can be constructed economically.

  The first portion of the reinforcing member may extend upward from the end portion of the bottom plate, reach the inside of the side wall, and be fixed to the side wall inside the side wall. Accordingly, when the end portion of the bottom plate receives the tensile force from the earth retaining wall, the tensile force is transmitted from the end portion of the bottom plate to the second portion via the first portion of the reinforcing member. At the same time, it can be transmitted to the side wall. For this reason, the said tensile force can be borne on both the said 2nd part and the said side wall of the said reinforcement member, and the said edge part of the said bottom slab can be reinforced more effectively.

  The reinforcing member is a third portion that is spaced from the second portion and is perpendicular to the first portion, extends inwardly from the end of the bottom plate, and is fixed to the bottom plate. It is possible to have a third part formed. Accordingly, when the end portion of the bottom plate receives the tensile force from the retaining wall, the tensile force is transmitted from the end portion of the bottom plate to the second portion and the second portion via the first portion of the reinforcing member. You can tell the third part. For this reason, the said tensile force can be borne by the said 2nd part and the said 3rd part, and the said edge part of the said bottom slab can be reinforced more effectively.

  The retaining wall is provided at intervals on the surface of the retaining wall, each having a plurality of protrusions protruding in a horizontal direction from the surface, and the end portion of the bottom plate receives each protrusion. The first portion of the reinforcing member is horizontally spaced from the surface of the retaining wall, and the spacing between the surface of the retaining wall and the first portion of the reinforcing member is the retaining wall. Less than the distance between the surface of the projection and the tip of the protrusion.

  When the end portion of the bottom plate receives the tensile force from the retaining wall, the tensile force is transmitted from the retaining wall to the end portion of the bottom plate through the protrusion. Since the distance between the surface of the retaining wall and the first portion of the reinforcing member is smaller than the distance between the surface of the retaining wall and the tip of the protrusion, the protrusion is removed from the retaining wall. Thus, the tensile force transmitted to the end portion of the bottom plate can be reliably transmitted to the first portion of the reinforcing member, and the end portion of the bottom plate can be more effectively reinforced.

  According to the present invention, when an external force acting in a direction orthogonal to the retaining wall above the bottom slab acts and the end portion of the bottom slab receives a tensile force from the retaining wall, the tensile force is The end portion of the reinforcing member is transmitted to the second portion via the first portion of the reinforcing member, and the second portion resists the tensile force. Thereby, the said edge part of the said bottom plate can be reinforced, and it can prevent reliably that the said edge part of the said bottom plate receives the said tensile force from the said earth retaining wall, and destroys.

The longitudinal cross-sectional view of the foundation of a building based on 1st Example of this invention. FIG. 3 is an enlarged view of a building foundation in line 2 of FIG. 1. FIG. 3 is a horizontal sectional view of the foundation of the building at line 3 in FIG. 2. The longitudinal cross-sectional view of the foundation of a building based on 2nd Example of this invention. The longitudinal cross-sectional view of the foundation of a building based on 3rd Example of this invention. The horizontal sectional view of the foundation of the building based on 4th Example of this invention. The horizontal sectional view of the foundation of the building based on 5th Example of this invention.

  As shown in FIGS. 1 and 2, a building foundation 14 using a retaining wall 12 provided in the ground 10 is constructed. The foundation 14 has a bottom plate 18 provided perpendicular to the retaining wall 12 below the surface 16 of the ground 10, and the bottom plate has an end 20 coupled to the retaining wall 12. The foundation 14 has a side wall 22 provided parallel to the retaining wall 12 on the end 20 of the bottom plate 18, and the side wall is connected to the bottom plate 18 and the retaining wall 12. Each of the bottom plate 18 and the side wall 22 is made of reinforced concrete.

  The foundation 14 is disposed inside the end portion 20 of the bottom plate 18 in parallel with the retaining wall 12, and includes a first portion 24 fixed to the end portion 20 and a second portion 26 perpendicular to the first portion. The reinforcing member 28 has a second portion 26 that extends inward from the end portion 20 in the first horizontal direction (left-right direction in FIG. 1) and is fixed to the bottom plate 18. In the example shown in FIGS. 1 and 2, the first portion 24 extends in the vertical direction. The reinforcing member 28 is an L-shaped reinforcing bar and reinforces the end 20 of the bottom plate 18.

  The retaining wall 12 is provided at a distance from the surface 30 of the retaining wall, and has a plurality of first protrusions 32 projecting from the surface 30 in the first horizontal direction. The first protrusion 32 is received. The end 20 of the bottom plate 18 is coupled to the surface 30 of the retaining wall 12 and the first protrusion 32. The earth retaining wall 12 has a plurality of second protrusions 34 spaced from the surface 30 above the first protrusions 32, and the side walls 22 receive the second protrusions 34. The side wall 22 is coupled to the surface 30 of the retaining wall 12 and the second protrusion 34.

  The retaining wall 12 is a soil cement column wall, as shown in FIG. 3, a main body 36 made of soil cement, and a plurality of steel members 38 that are arranged adjacent to the inside of the main body and each extend in the vertical direction. Have The steel material 38 is disposed inside the main body 36 adjacent to a second horizontal direction (vertical direction in FIG. 3) orthogonal to the first horizontal direction. A part of each steel material 38 is exposed from the main body 36, and each of the first protrusion 32 and the second protrusion 34 is a stud fixed to the part of the steel material 38.

  The bottom surface of the bottom plate 18 is in contact with the ground 10. In the example shown in FIG. 1, the bottom plate 18 is positioned at a height higher than the lower end portion 12 a of the retaining wall 12, but may be positioned at the same height as the lower end portion 12 a of the retaining wall 12 instead. An upper structure 40 of the building is constructed on the bottom slab 18, and a seismic isolation device 42 is interposed between the bottom slab 18 and the upper structure 40.

  When constructing the foundation 14, first, an area of the ground 10 that is in contact with the surface 30 of the retaining wall 12 is excavated from the surface 16 of the ground 10 to the lower end 12 a of the retaining wall 12 or above the lower end. Next, a reinforcing member 28 having a first portion 24 parallel to the retaining wall 12 and a second portion 26 perpendicular to the first portion is placed in the region so that the first portion 24 is adjacent to the retaining wall 12. It arrange | positions above the ground 10. Thereafter, concrete is cast on the ground 10 in the region to provide the bottom plate 18. At this time, the concrete is driven up above the reinforcing member 28. After the bottom plate 18 is provided, a side wall 22 connected to the retaining wall 12 and parallel to the retaining wall 12 is provided on the bottom plate 18.

  Earth pressure and water pressure are applied from the ground 10 to the retaining wall 12 above the bottom plate 18. Further, a horizontal force acts on the retaining wall 12 above the bottom slab 18 at the time of an earthquake. Thus, when an external force in a direction orthogonal to the retaining wall 12 above the bottom plate 18 acts, the retaining wall 12 is bent and deformed, and the end 20 of the bottom plate 18 receives a tensile force from the retaining wall 12. A reinforcing member 28 is disposed in the end portion 20 of the bottom slab 18 in parallel with the retaining wall 12 and includes a first portion 24 fixed to the end portion 20 and a second portion 26 perpendicular to the first portion. When the end 20 of the bottom slab 18 receives the tensile force from the retaining wall 12 because it has the second horizontal portion 26 that extends inward from the end 20 in the first horizontal direction and is fixed to the bottom slab 18. The tensile force is transmitted from the end portion 20 of the bottom plate 18 to the second portion 26 via the first portion 24 of the reinforcing member 28, and the second portion resists the tensile force. As a result, the end 20 of the bottom slab 18 can be reinforced, and the end 20 of the bottom slab 18 can be prevented from being broken by receiving the tensile force from the earth retaining wall 12.

  Since the side wall 22 is coupled to the retaining wall 12, the horizontal force acting on the side wall 22 during an earthquake can be reliably transmitted to the retaining wall 12, and the horizontal force can be borne by the retaining wall 12. Thereby, the load which the side wall 22 bears can be reduced, the side wall 22 can be made thin, and the foundation of a building can be constructed economically.

  As shown in FIG. 2, the first portion 24 of the reinforcing member 28 is spaced 44 from the surface 30 of the retaining wall 12 in the first horizontal direction, and the first surface 24 of the retaining wall 12 and the first portion of the reinforcing member 28. The distance 44 between the first portion 24 is smaller than the distance 46 between the surface 30 of the retaining wall 12 and the tip of the first protrusion 32. The first portion 24 of the reinforcing member 28 intersects at least one of the first protrusions 32 when viewed in the longitudinal section of the bottom plate 18. In the example illustrated in FIG. 2, the first portion 24 of the reinforcing member 28 intersects with a plurality of the first protrusions 32, but may alternatively intersect with one of the first protrusions 32. .

  When the end portion 20 of the bottom plate 18 receives the tensile force from the retaining wall 12, the tensile force is transmitted from the retaining wall 12 to the end portion 20 of the bottom plate 18 through the first protrusion 32. Since the distance 44 between the surface 30 of the retaining wall 12 and the first portion 24 of the reinforcing member 28 is smaller than the distance 46 between the surface 30 of the retaining wall 12 and the tip of the first protrusion 32, the retaining wall 12. The tensile force transmitted from the first protrusion 32 to the end portion 20 of the bottom plate 18 can be reliably transmitted to the first portion 24 of the reinforcing member 28, and the end portion 20 of the bottom plate 18 can be more effectively reinforced. Can do.

  As shown in FIG. 3, the end portion 20 of the bottom plate 18 connects the tip end portion of the first projection 32 and the end surface 20 a of the bottom plate 18 which are inclined at an angle of 45 ° with respect to the first projection 32. A conical region 50 surrounded by a conical surface 48 corresponding to the locus of the straight line obtained when the straight line is rotated around the first protrusion 32 and the end surface 20a of the bottom plate 18; The one portion 24 passes through the conical region 50. In the example shown in FIG. 3, the straight line extends from an intersection line 32 a between the peripheral surface and the end surface of the tip portion of the first protrusion 32 to the end surface 20 a of the bottom plate 18.

  When the end portion 20 of the bottom plate 18 receives the tensile force from the retaining wall 12, the tensile force is transmitted from the retaining wall 12 to the conical region 50 through the first protrusion 32. For this reason, the conical region 50 is separated from the surrounding region of the conical region, that is, the end portion 20 of the bottom plate 18 may be cone-shaped. Since the first portion 24 of the reinforcing member 28 passes through the conical region 50, the tensile force transmitted from the retaining wall 12 to the conical region 50 via the first protrusion 32 is transmitted to the reinforcing member 28, and the reinforcing member Resists the tensile force. For this reason, it is possible to prevent the conical region 50 from being separated from the surrounding region, and it is possible to prevent the cone-shaped destruction of the end portion 20 of the bottom plate 18.

  The reinforcing member 28 may be another bar-shaped member such as a steel bar instead of the example shown in FIG. 2 which is a reinforcing bar. Further, the reinforcing member 28 may be made of a plurality of combined steel materials instead of the example shown in FIG. 2 made of one steel material such as a reinforcing bar. In the example shown in FIG. 2, the second portion 26 of the reinforcing member 28 is located below the center 52 in the thickness direction of the bottom plate 18, but instead, may be located above the center 52, It may be located at the center 52. The reinforcing member 28 may be T-shaped instead of the L-shaped example shown in FIG. The reinforcing member 28 is replaced with the example shown in FIG. 2 in which both the first portion 24 and the second portion 26 are rod-shaped, and both the first portion 24 and the second portion 26 may be plate-shaped, or the first portion One of 24 and the second portion 26 may be rod-shaped and the other may be plate-shaped.

  In the example shown in FIG. 2, the entire first portion 24 of the reinforcing member 28 is located inside the end portion 20 of the bottom plate 18. Instead, in the example shown in FIG. 4, the first portion of the reinforcing member 28 is used. 24 extends upward from the end 20 of the bottom plate 18 and reaches the inside of the side wall 22. The first portion 24 is fixed to the side wall 22 inside the side wall 22. Thus, when the end portion 20 of the bottom slab 18 receives the tensile force from the retaining wall 12, the tensile force is transmitted from the end portion 20 of the bottom slab 18 to the second portion 26 via the first portion 24 of the reinforcing member 28. At the same time, it can be transmitted to the side wall 22. For this reason, the said tensile force can be borne on both the 2nd part 26 and the side wall 22 of the reinforcement member 28, and the edge part 20 of the base 18 can be reinforced more effectively.

  In the example shown in FIG. 5, instead of the example shown in FIG. 2 in which the reinforcing member 28 has only the first portion 24 and the second portion 26, the reinforcing member 28 includes the first portion 24 and the second portion 26, The third portion 54 is perpendicular to the first portion 24 and is spaced from the two portions 26. The third portion 54 extends inward from the end 20 of the bottom plate 18 in the first horizontal direction and is fixed to the bottom plate 18. Thus, when the end portion 20 of the bottom plate 18 receives the tensile force from the retaining wall 12, the tensile force is transmitted from the end portion 20 of the bottom plate 18 to the second portion 26 and the second portion 26 via the first portion 24 of the reinforcing member 28. Can be transmitted to the third portion 54, and can be borne by the second portion 26 and the third portion 54. For this reason, the edge part 20 of the bottom plate 18 can be reinforced more effectively. The second portion 26 is located below the center 52 in the thickness direction of the bottom plate 18, and the third portion 54 is located above the center 52. The reinforcing member 28 is an inverted U-shaped reinforcing bar.

  In the example shown in FIG. 6, the first portion 24 of the reinforcing member 28 extends in the second horizontal direction instead of the example shown in FIG. 2 extending in the vertical direction. The first portion 24 of the reinforcing member 28 intersects at least one of the first protrusions 32 when viewed in a horizontal plane. In the example shown in FIG. 6, the first portion 24 of the reinforcing member 28 intersects with a plurality of the first protrusions 32, but may instead intersect with one of the first protrusions 32. The first portion 24 of the reinforcing member 28 passes through the conical region 50. The first portion 24 of the reinforcing member 28 may be inclined with respect to each of the second horizontal direction and the vertical direction instead of the example shown in FIG. 6 extending in the second horizontal direction.

  In the example shown in FIG. 6, the reinforcing member 28 is L-shaped. Instead, in the example shown in FIG. 7, the reinforcing member 28 is reverse U-shaped. In this case, the reinforcing member 28 is a third portion 54 that is spaced from the second portion 26 and is perpendicular to the first portion 24 and inward from the end 20 of the bottom plate 18 in the first horizontal direction. And has a third portion 54 fixed to the bottom plate 18. In the example shown in FIG. 7, the first portion 24 of the reinforcing member 28 intersects with one of the first protrusions 32 when viewed in a horizontal plane. Instead, the first portion 24 is replaced with the first protrusion 32. A plurality of them may be crossed.

  The retaining wall 12 may be a steel pipe sheet pile, a steel sheet pile, a parent pile horizontal sheet pile, or the like, instead of the illustrated example of a soil cement column wall. In the illustrated example, the building superstructure 40 is separated from the side wall 22, but may instead be coupled to the side wall 22. In this case, the side wall 22 may constitute a part of the upper structure 40.

DESCRIPTION OF SYMBOLS 10 Ground 12 Retaining wall 14 Foundation 16 Surface of foundation 18 Bottom plate 20 End part 22 Side wall 24 First part 26 Second part 28 Reinforcing member 30 Surface of retaining wall 32 Protrusion (first protrusion)
54 Third part

Claims (7)

It is the foundation of a building using a retaining wall provided in the ground,
A bottom plate provided perpendicularly to the retaining wall below the surface of the ground and having an end coupled to the retaining wall;
A first part fixed to the end and a second part perpendicular to the first part and disposed inward of the end of the bottom plate and inward from the end. And a reinforcing member having a second portion extending in a horizontal direction and fixed to the bottom plate.   The building foundation according to claim 1, comprising a side wall provided parallel to the retaining wall on the end of the bottom slab and coupled to the retaining wall.   The building foundation according to claim 2, wherein the first portion of the reinforcing member extends upward from the end portion of the bottom plate, reaches the inside of the side wall, and is fixed to the side wall inside the side wall. .   The reinforcing member is a third portion that is spaced from the second portion and is perpendicular to the first portion, extends inwardly from the end of the bottom plate, and is fixed to the bottom plate. Building foundation according to claim 1 or 2, having a third part formed.   The retaining wall is provided at intervals on the surface of the retaining wall, each having a plurality of protrusions protruding horizontally from the surface, and the end portion of the bottom plate receives each protrusion. The building foundation according to any one of Items 1 to 4.   The first portion of the reinforcing member is horizontally spaced from the surface of the retaining wall, and the spacing between the surface of the retaining wall and the first portion of the reinforcing member is the retaining wall. The building foundation according to claim 5, wherein the foundation is smaller than the distance between the surface of the projection and the tip of the protrusion.   The end portion of the bottom plate is obtained by rotating a straight line connecting the tip end portion of the protrusion and the end surface of the bottom plate, which is inclined at an angle of 45 ° with respect to the protrusion, around the protrusion. The conical region surrounded by a conical surface corresponding to the locus of the straight line and the end surface of the bottom plate, and the first portion of the reinforcing member passes through the conical region. The building foundation described.

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