Foundation of building and method for constructing foundation of building
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SEKISUI HOUSE KK
- Filing Date
- 2025-07-25
- Publication Date
- 2026-07-30
Smart Images
Figure JP2025026444_30072026_PF_FP_ABST
Abstract
Description
Building foundation and construction method of building foundation
[0001] The present disclosure relates to a building foundation and a construction method of a building foundation.
[0002] As an example of a building foundation, a foundation having a base portion and a rising portion is known. The base portion is also called a footing. The foundation is provided in a ground trench portion. The ground trench portion is backfilled with backfill soil. In some cases, a ground concrete may be provided on top of the backfill soil. The ground concrete may sink due to the shrinkage of the backfill soil. In Patent Document 1, a support for supporting the ground concrete is provided on the footing of the mat foundation.
[0003] Japanese Patent Application Laid-Open No. 2010-95920
[0004] The sinking of the ground concrete is caused by the shrinkage of the backfill soil. There is a need for a support structure for the ground concrete that is difficult to sink even when the backfill soil shrinks.
[0005] (1) The foundation according to one aspect of the present disclosure is a building foundation, comprising a rising portion extending in the vertical direction and a ground portion connected to the rising portion. The rising portion has a ground receiving portion embedded therein. The ground portion has a ground skeleton portion for supporting the ground portion. The ground skeleton portion is connected to the ground receiving portion. According to this configuration, the ground portion is supported by the ground receiving portion. Therefore, when the soil backfilled in the ground trench portion sinks or shrinks, the sinking of the ground portion can be suppressed.
[0006] (2) In the building foundation of (1) above, the portion where the ground skeleton portion and the ground receiving portion are connected is covered with concrete. According to this configuration, corrosion of the metal member disposed in the ground receiving portion can be reduced by the concrete.
[0007] (3) In the building foundation of (2) above, the ground skeleton portion has a first reinforcing bar for supporting the ground portion and a second reinforcing bar connected to the ground receiving portion. The end of the second reinforcing bar is connected to the ground receiving portion. According to this configuration, the ground portion is fixed to the rising portion via the second reinforcing bar.
[0008] (4) In the foundation of the building described in (3) above, the floor support portion has an engaging member, the engaging member has an engaging end that is exposed from the rising portion, and the end of the second reinforcing bar is connected to the engaging end of the engaging member. With this configuration, the end of the second reinforcing bar is fixed to the floor support portion.
[0009] (5) In the foundation of the building described in (4) above, the engaging end of the engaging member protrudes from the rising portion, and the end of the second reinforcing bar extends in the same direction as the engaging end of the engaging member. With this configuration, the end of the second reinforcing bar and the engaging end of the engaging member can be easily connected.
[0010] (6) In the foundation of the building described in (5) above, the engaging end of the engaging member has a male thread, the end of the second reinforcing bar has a male thread, and the engaging end of the engaging member and the end of the second reinforcing bar are connected by a nut having a female thread. With this configuration, the end of the second reinforcing bar and the engaging end of the engaging member can be easily connected by a nut.
[0011] (7) In the foundation of the building described in (4) or (5) above, the engaging member of the rising portion extends along the width direction of the rising portion, the engaging end of the engaging member protrudes from a recess provided on the side surface of the rising portion, the floor portion is connected to the side surface of the rising portion, and the second reinforcing bar of the floor portion is connected to the engaging end of the engaging member. With this configuration, the length of the engaging end that protrudes from the side surface of the rising portion can be shortened, thereby suppressing corrosion of the connection portion, which is the part where the end of the second reinforcing bar and the engaging end of the engaging member are connected.
[0012] (8) In the foundation of the building described in (7) above, the engaging member is composed of separator components that separate the two formwork used to form the rising portion. With this configuration, the separator components can be used as engaging members.
[0013] (9) In the foundation of the building described in (4) above, the engaging member of the rising portion extends along the vertical direction, the engaging end of the engaging member protrudes from the upper surface of the rising portion, the floor portion is connected to the upper part of the rising portion, and the second reinforcing bar of the floor portion is connected to the engaging end of the engaging member. With this configuration, the end of the second reinforcing bar is fixed to the floor support portion.
[0014] (10) In the foundation of the building described in (9) above, the engaging member is made up of additional anchor bolts extending in the vertical direction. With this configuration, the floor slab can be supported by a rising portion that supports the floor slab from below.
[0015] (11) In the foundation of a building described in any one of (1) to (10) above, the bottom surface at the end of the floor slab slopes downward from the floor slab toward the rising section. With this configuration, the corrosion of the metal member placed in the floor slab support can be reduced by the concrete.
[0016] (12) A method for constructing the foundation of a building according to one aspect of the present disclosure includes: a first step of setting up formwork in a ground trench; a second step of arranging reinforcing bars and engaging members as floor slab support parts in the formwork; a third step of forming a rising portion by filling the formwork with cement; a fourth step of exposing the engaging end of the engaging member from the side of the rising portion; a fifth step of connecting the second reinforcing bar, of the first and second reinforcing bars constituting the floor slab framework, to the engaging end; a sixth step of backfilling the ground trench with soil; a seventh step of arranging the first reinforcing bar; and an eighth step of pouring cement for forming the floor slab. This configuration makes it possible to form a foundation that can suppress the settlement of the floor slab.
[0017] (13) A method for constructing the foundation of a building according to one aspect of the present disclosure includes: a first step of setting up formwork in a ground trench; a second step of arranging reinforcing bars and engaging members as floor slab support parts in the formwork; a third step of forming the rising part by filling the formwork with cement so that the engaging end of the engaging member is exposed from the upper surface of the rising part; a fourth step of backfilling the ground trench with soil; a fifth step of connecting the second reinforcing bar, of the first and second reinforcing bars constituting the floor slab framework, to the engaging end; a sixth step of arranging the first reinforcing bar; and a seventh step of pouring cement for forming the floor slab. With this configuration, a foundation that can suppress the settlement of the floor slab can be formed.
[0018] According to the building foundation and construction method for the building foundation of this disclosure, settlement of the ground slab can be suppressed when the soil backfilled in the ground trench settles or shrinks.
[0019] This is a cross-sectional view of the foundation of a building in the first embodiment. This is a perspective view of the floor slab frame of the foundation of the building in Figure 1. This is an enlarged view of the floor slab support section in Figure 1. This is a cross-sectional view of a modified example of the foundation in the first embodiment. This is a cross-sectional view of the construction method for the foundation of a building. This is a cross-sectional view of the construction method for the foundation of a building. This is a cross-sectional view of the construction method for the foundation of a building. This is a cross-sectional view of the foundation of a building in the second embodiment. This is an enlarged view of the floor slab support section in Figure 9.
[0020] <First Embodiment> The foundation 10 of the building in this embodiment will be described with reference to Figures 1 to 8. The foundation 10 in this embodiment is a deep foundation.
[0021] [Building Foundation] As shown in Figure 1, the building foundation 10 comprises a foundation section 11 and a floor section 21. The foundation section 11 has a base section 12 and a rising section 13. The base section 12 is also called a footing. The base section 12 is provided in a ground trench section 4 formed by excavating the ground 1. The ground trench section 4 is provided in the area of the ground 1 where the foundation section 11 is to be provided. The ground 1 is divided into a first ground area 2 and a second ground area 3, with the ground trench section 4 in between. The first ground area 2 is the part that extends outside the building in a plan view. The second ground area 3 is the part located below the building in a plan view. Crushed stone 6 is provided at the bottom of the ground trench section 4. The surface of the crushed stone 6 is flattened. The base section 12 is provided on the surface of the crushed stone 6. The rising section 13 is provided so as to extend vertically from the base section 12. The foundation section 11 and the floor section 21 are made of reinforced concrete. The floor section 21 is connected to the rising section 13. In this embodiment, the floor section 21 is connected to the side surface 13A of the rising section 13.
[0022] The trench 4 surrounding the foundation 11 is backfilled with soil 5. During the backfilling process, soil 5 is returned to the trench 4 so that a predetermined thickness is filled in each backfilling step. After one backfilling step is completed, the backfilled soil 5 is compacted. Compaction is performed to solidify the backfilled soil 5. The backfilling and compaction process is carried out multiple times. Since settlement is expected with ordinary soil, conventional techniques use crushed stone as backfilling soil that minimizes settlement. In this embodiment, as the floor slab 21 is supported as described later, the soil 5 excavated from the ground 1 is used as backfilling soil. An example of the backfilling thickness per step after compacting the soil 5 is 30 cm.
[0023] In the ground trench section 4, the trench portion between the second ground area 3 and the rising section 13 is backfilled with soil 5 so as to provide space for forming the portion on the rising section 13 side in the floor section 21. Specifically, the trench portion is backfilled with soil 5 so as to form an upper surface 5A, an inclined surface 5C that slopes downward toward the rising section 13 from the end 5B on the rising section 13 side of the upper surface 5A, and a bottom portion 5D that extends horizontally from the end 5E on the rising section 13 side of the inclined surface 5C. The upper surface 5A is located at the same height as the upper surface 3A of the second ground area 3.
[0024] [Floor support section] As shown in Figures 1 to 4, the rising section 13 has a floor support section 30 embedded in the rising section 13. The floor section 21 has a floor frame section 23 that supports the floor section 21. The floor frame section 23 is connected to the floor support section 30. In other words, the floor section 21 is supported by the foundation section 11 because the floor support section 30 of the rising section 13 supports the floor frame section 23. The part where the floor frame section 23 and the floor support section 30 are connected is covered with concrete.
[0025] The floor slab framework 23 includes a first reinforcing bar 24 that supports the floor slab 21 and a second reinforcing bar 25 that connects to the floor slab support section 30. The first reinforcing bar 24 is positioned at the vertical center of the flat portion of the floor slab 21 in order to support the floor slab 21. The end 25D of the second reinforcing bar 25 is connected to the floor slab support section 30. The second reinforcing bar 25 includes a first horizontal portion 25A, an inclined portion 25B, and a second horizontal portion 25C.
[0026] The first horizontal portion 25A of the second reinforcing bar 25 is positioned to extend horizontally from the floor support portion 30 provided on the side surface 13A of the rising portion 13. However, it is not limited to this, and may be positioned to extend inclined from the floor support portion 30.
[0027] The inclined portion 25B of the second reinforcing bar 25 is positioned to extend upward parallel to the inclined surface 5C. The inclined portion 25B is separated from the inclined surface 5C. The inclined portion 25B intersects with the first reinforcing bar 24 above the inclined surface 5C. At the point of intersection, the second reinforcing bar 25 is bent again so as to be parallel to the first reinforcing bar 24, and is continuously connected to the second horizontal portion 25C.
[0028] The second horizontal portion 25C of the second reinforcing bar 25 has a portion that overlaps with the first reinforcing bar 24 within the floor slab framework 23. At the portion where the first reinforcing bar 24 and the second reinforcing bar 25 overlap, the first reinforcing bar 24 and the second reinforcing bar 25 are joined together. In one example, they are joined with wire or the like.
[0029] Figure 2 is a perspective view showing only the structure of the rising section 13, the first reinforcing bar 24, and the second reinforcing bar 25. The expansion in the forward direction (left direction in Figure 2) and the depth direction D1 (right direction in Figure 2) is omitted. As shown in Figure 2, the first reinforcing bar 24 and the second reinforcing bar 25 are arranged periodically in the depth direction D1 of the rising section 13. In one example, the first reinforcing bar 24 is arranged in a mesh-like and planar manner at 20 cm intervals, and the second reinforcing bar 25 is arranged at 50 cm intervals. The spacing of the second reinforcing bar 25 matches the spacing of the floor support section 30.
[0030] [Fixing structure using engaging members] Referring to Figures 1 and 3, the fixing structure between the rising portion 13 and the second reinforcing bar 25 using engaging members 40 will be described.
[0031] The floor support portion 30 has an engaging member 40. The engaging member 40 has an engaging body portion 43, a first engaging end portion 43A, and a second engaging end portion 43B opposite to the first engaging end portion 43A. The first engaging end portion 43A is located on the first ground area 2 side of the rising portion 13. The second engaging end portion 43B is located on the second ground area 3 side of the rising portion 13. The engaging member 40 extends along the width direction of the rising portion 13, which is perpendicular to the side surface 13A of the rising portion 13.
[0032] As shown in Figure 3, the engaging body portion 43 and the first engaging end portion 43A are embedded in the rising portion 13. The second engaging end portion 43B is exposed from the rising portion 13. The first horizontal portion 25A of the second reinforcing bar 25 has an end portion 25D near the rising portion 13. The end portion 25D of the second reinforcing bar 25 is connected to the second engaging end portion 43B of the engaging member 40. In other words, the second reinforcing bar 25 of the floor portion 21 is connected to the second engaging end portion 43B of the engaging member 40.
[0033] The second engaging end 43B protrudes from the rising portion 13. In one example, it protrudes horizontally, which is perpendicular to the side surface 13A of the rising portion 13. Since the first horizontal portion 25A of the second reinforcing bar 25 is positioned to extend horizontally toward the side surface 13A of the rising portion 13, its end 25D extends horizontally. Therefore, the end 25D of the second reinforcing bar 25 extends horizontally, which is in the same direction as the second engaging end 43B of the engaging member 40.
[0034] The second engaging end 43B of the engaging member 40 has a male thread. The end 25D of the second reinforcing bar 25 has a male thread. The second engaging end 43B of the engaging member 40 and the end 25D of the second reinforcing bar 25 are connected by a nut 62 having a female thread. Since the second engaging end 43B of the engaging member 40 and the end 25D of the second reinforcing bar 25 extend in the same direction and in opposing directions, the nut 62 can be connected from both directions. The nut 62 is screwed into the second engaging end 43B of the engaging member 40 and positioned in a recess 48 on the side surface 13A of the rising portion 13. The surface of the nut 62 opposite to the surface that contacts the bottom surface of the recess 48 is flush with the side surface 13A of the rising portion 13. However, it is not limited to this, and the surface of the nut 62 opposite to the surface that contacts the bottom surface of the recess 48 may be positioned outside the recess 48 of the rising portion 13 or inside the recess 48 of the rising portion 13.
[0035] As shown in Figures 1 and 5, in this embodiment, the engaging member 40 is composed of components of a separator 41 that separates the two formwork 53 used to form the rising portion 13. Specifically, the engaging member 40 is one of the components of the separator 41. The separator 41 comprises a separator body that constitutes the engaging member 40, an accessory member 44, a first formwork engaging portion 45, and a second formwork engaging portion 46.
[0036] The first formwork engagement portion 45 is fixed to the rising formwork 53 and is configured to be coupled to the first engagement end 43A of the engagement member 40. The first formwork engagement portion 45 has a clamping portion 45A and an axial coupling portion 45B extending from the clamping portion 45A. The clamping portion 45A is positioned between two rising formwork 53 stacked vertically and is clamped by the two rising formwork 53. The axial coupling portion 45B is the portion that protrudes from the rising formwork 53 when the clamping portion 45A is positioned between the two rising formwork 53. The axial coupling portion 45B is the portion that is coupled to the first engagement end 43A of the engagement member 40.
[0037] The second formwork engagement portion 46 comprises a coupling portion 46A that connects to the attached member 44, a clamping portion 46B that is sandwiched between the two rising formwork portions 53, and an extension portion 46C that extends from the clamping portion. The extension portion 46C protrudes from the rising formwork portion 53. The extension portion 46C is provided with a hole through which a fastening member 47 is inserted. The fastening member 47 is a wedge member for fastening the second formwork engagement portion 46 to the rising formwork portion 53.
[0038] The accessory member 44 is also called a P-con (plastic cone, or form tie cone). The accessory member 44 has a cover portion 44A that covers the second engaging end 43B of the engaging member 40 and engages with the second engaging end 43B of the engaging member 40 in a detachable manner, and a protruding shaft 44B that protrudes from the cover portion 44A. The protruding shaft 44B is connected to the second formwork engaging portion 46. The shaft unit is formed by attaching the accessory member 44 to the second engaging end 43B of the engaging member 40. The first formwork engaging portion 45 is attached to one end of the shaft unit, and the second formwork engaging portion 46 is attached to the other end, which is the end on the accessory member 44 side.
[0039] The attached member 44 is attached to the second engaging end 43B of the engaging member 40 such that the end face of the cover portion 44A contacts the side surface of the formwork 53 of the rising portion 13 during construction. This allows the second engaging end 43B of the engaging member 40 to be exposed by removing the attached member 44 from the separator body embedded in the rising portion 13 when the cement inserted into the rising portion 13 has hardened. When the attached member 44 is removed from the separator body in the rising portion 13 after the cement has hardened, a recess 48 (see Figures 3 and 6) is formed on the side surface 13A of the rising portion 13, which is the site where the cover portion 44A was removed. The second engaging end 43B of the engaging member 40 is located within the recess 48. The second engaging end 43B protrudes from the recess 48 provided on the side surface 13A of the rising portion 13. As described above, the second reinforcing bar 25 is connected to the second engaging end 43B of the engaging member 40.
[0040] When the nut 62 is used to connect the second engaging end 43B to the second reinforcing bar 25, a gap is formed between the outside of the nut 62 (the upper and lower sides of the nut 62 in Figure 3) and the recess 48. This gap is filled with mortar. However, it is not limited to this, and may also be filled with cement poured into the floor slab 21 when it is formed.
[0041] As described above, the second reinforcing bar 25 is connected to the engaging member 40. This allows the second reinforcing bar 25 to be fixed to the side surface 13A of the rising section 13. In this embodiment, the second reinforcing bar 25 is connected to the separator 41, which is the engaging member 40. The second engaging end 43B of the engaging member 40 of the separator 41 and the end 25D of the second reinforcing bar 25 are fastened together by a nut 62. With this structure, the second reinforcing bar 25 is fixed to the side surface 13A of the rising section 13, and the floor section 21 is supported by the rising section 13. At this time, the bottom surface of the end of the floor section 21 on the rising section 13 side slopes downward from the floor section 21 toward the rising section 13.
[0042] As shown in FIG. 4, the dirt floor portion 21 may be provided such that the height of the upper surface 21A of the dirt floor portion 21 is lower than the height of the upper surface 2A of the first ground region 2. In this case, it is preferable that a water stop member 71 is provided near the center of the separator 41.
[0043] [Construction method of building foundation] The construction method 50 of the building foundation 10 will be described with reference to FIGS. 5 to 8 and FIG. 1. As shown in FIGS. 5 to 8, the construction of the building foundation 10 is carried out as follows. The construction method 50 of the foundation 10 includes the first to eighth steps.
[0044] In the first step, as shown in FIG. 5, a formwork is installed in the ground groove portion 4. Specifically, first, the ground 1 is excavated to provide the ground groove portion 4. Crushed stone 6 is arranged at the bottom of the ground groove portion 4. Next, on the crushed stone 6, a base portion formwork 51 and a rising portion formwork base 52 are arranged. The base portion formwork 51 is arranged in parallel on the crushed stone 6 with a gap therebetween. The base portion formwork 51 is a member that determines the width of the base portion 12 when forming the base portion 12. A rising portion formwork base 52 is arranged between the two base portion formworks 51. On the rising portion formwork base 52, rising portion formworks 53 are arranged in parallel with a gap therebetween. The rising portion formworks 53 are arranged one above the other vertically. The interval between the rising portion formworks 53 is arranged to be narrower than the interval between the base portion formworks 51.
[0045] In the second step, as shown in FIG. 5, in order to increase the strength of the foundation portion 11, reinforcing steel bars 54 are arranged in the base portion formwork 51 and in the rising portion formwork 53. Further, a separator 41, which is also an engaging member 40 as the dirt floor receiving portion 30, is arranged in the two rising portion formworks 53. The separator 41 is fixed to one rising portion formwork 53 by the first formwork engaging portion 45. The separator 41 is fixed to the other rising portion formwork 53 by the second formwork engaging portion 46. The interval between the two rising portion formworks 53 arranged in parallel is maintained by the separator 41.
[0046] In the third step, the rising portion 13 is formed by filling cement into the base formwork 51 and the rising formwork 53. Specifically, cement is poured between the parallelly arranged base formworks 51 and between the parallelly arranged rising formworks 53.
[0047] In the fourth step, as shown in FIG. 6, the second engaging end portion 43B of the engaging member 40 is exposed from the side surface 13A of the rising portion 13. Specifically, after the cement poured in the third step has hardened, the base formwork 51 and the rising formwork 53 are removed from the rising portion 13. The separator 41 is embedded in the rising portion 13. When the accessory member 44 is removed from the engaging member 40 of the embedded separator 41, a recess 48, which is a trace where the cover portion 44A has come off, is formed on the side surface 13A of the rising portion 13. The second engaging end portion 43B of the engaging member 40 is present in the recess 48.
[0048] In the fifth step, as shown in FIG. 7, of the first reinforcing bar 24 and the second reinforcing bar 25 that constitute the dirt floor framework portion 23, the second reinforcing bar 25 is connected to the second engaging end portion 43B. Since the second engaging end portion 43B of the separator 41 has a male thread, a nut 62 is fastened to the second engaging end portion 43B of the engaging member 40 of the separator 41. Further, the end portion 25D of the second reinforcing bar 25 having a male thread is screwed into the female thread portion of the nut 62 on the side opposite to the side where the second engaging end portion 43B is connected. Thereby, the second reinforcing bar 25 is fixed to the second engaging end portion 43B disposed on the side surface 13A of the rising portion 13.
[0049] The second reinforcing bar 25 is bent between the first horizontal portion 25A and the inclined portion 25B and between the inclined portion 25B and the second horizontal portion 25C. Thereby, the second reinforcing bar 25 having the first horizontal portion 25A, the inclined portion 25B, and the second horizontal portion 25C is formed. Note that the second reinforcing bar 25 may be bent at these two locations in advance before being screwed into the nut 62, or may be bent after being screwed into the nut 62.
[0050] In the sixth step, as shown in Figure 8, the soil 5 is returned to the trench 4 in the backfilling work, in which soil 5 is returned to the trench 4 in such a way that a predetermined thickness is filled in one backfilling step. After the first backfilling step is completed, the backfilled soil 5 is compacted. Compaction is performed to solidify the backfilled soil 5. The backfilling work and compaction are performed multiple times. In the trench 4, the trench portion between the second ground area 3 and the rising portion 13 is backfilled with soil 5 so that a space is provided in the floor area 21 on the rising portion 13 side. Specifically, the trench portion is backfilled with soil 5 so that an upper surface 5A is formed, an inclined surface 5C that slopes downward toward the rising portion 13 from the end 5B on the rising portion 13 side of the upper surface 5A, and a bottom portion 5D that extends horizontally from the end 5E on the rising portion 13 side of the inclined surface 5C. The upper surface 5A is located at the same height as the upper surface 3A of the second ground area 3.
[0051] In the seventh step, the first reinforcing bar 24 is laid and, together with the second reinforcing bar 25, forms the slab framework 23. The second horizontal portion 25C of the second reinforcing bar 25 and the first reinforcing bar 24 are connected with wire or the like. In the eighth step, cement is poured to form the slab 21. This forms the slab 21 along the slab framework 23. The slab 21 is formed along the inclined surface 5C of the soil 5 so as to connect to the slab support portion 30. The slab 21 is made of concrete. The slab 21 is in contact with the upper surface 3A of the second ground area 3, the upper surface 5A of the soil 5, the inclined surface 5C, the bottom portion 5D, and the side surface 13A of the rising portion 13.
[0052] [Operation of the First Embodiment] The operation of this embodiment will now be explained. When soil 5 excavated to create the ground trench 4 is used to backfill the ground trench 4, a gap may be created between the floor slab 21 and the soil 5 of the ground trench 4 due to the settlement or shrinkage of the backfilled soil 5. In this case, a load due to the weight of the floor slab 21 itself is applied to the boundary between the rising section 13 and the floor slab 21. Since the rising section 13 and the floor slab 21 are formed in separate processes, the rising section 13 and the floor slab 21 are not essentially a single unit. Therefore, when a load is applied to the boundary between the rising section 13 and the floor slab 21, there is a risk that the floor slab 21 will separate from the rising section 13 at the boundary between the rising section 13 and the floor slab 21.
[0053] In this embodiment, the building foundation 10 has the following configuration. The building foundation 10 comprises a vertically extending riser 13 and a floor slab 21 connected to the riser 13. The riser 13 has a floor slab support 30 embedded in the riser 13. The floor slab 21 has a floor slab skeleton 23 that supports the floor slab 21. The floor slab skeleton 23 is connected to the floor slab support 30. With this configuration, the floor slab 21 is supported by the floor slab support 30. Therefore, when the soil 5 backfilled in the ground trench 4 settles or shrinks, the concentration of force at the boundary between the floor slab 21 and the riser 13 is mitigated. As a result, the floor slab 21 is less likely to peel off at the boundary between the floor slab 21 and the riser 13. In this way, settlement of the floor slab 21 can be suppressed.
[0054] [Effects of the First Embodiment] The effects of the first embodiment will be described. (1-1) The foundation 10 of the building comprises a vertically extending rising section 13 and a floor section 21 connected to the rising section 13. The rising section 13 has a floor support section 30 embedded in the rising section 13, and the floor section 21 has a floor frame section 23 that supports the floor section 21, and the floor frame section 23 is connected to the floor support section 30. With this configuration, the floor section 21 is supported by the floor support section 30. Therefore, if the soil 5 backfilled in the ground trench section 4 settles or shrinks, the settlement of the floor section 21 can be suppressed. As a result, the occurrence of separation at the boundary between the rising section 13 and the floor section 21 can be suppressed, and moisture can seep into the foundation from the boundary.
[0055] (1-2) In the foundation 10 of the building, the portion where the floor slab frame 23 and the floor slab support portion 30 are connected is covered with concrete. With this configuration, by covering the floor slab support portion 30 with concrete, corrosion of the metal members placed in the floor slab support portion 30 can be reduced.
[0056] (1-3) In the foundation 10 of the building, the floor slab frame 23 has a first reinforcing bar 24 that supports the floor slab 21 and a second reinforcing bar 25 that is connected to the floor slab support 30, and the end 25D of the second reinforcing bar 25 is connected to the floor slab support 30. With this configuration, the floor slab 21 is fixed to the rising section 13 via the second reinforcing bar 25.
[0057] (1-4) In the foundation 10 of the building, the floor support portion 30 has an engaging member 40, the engaging member 40 has an engaging end portion 43B that is exposed from the rising portion 13, and the end portion 25D of the second reinforcing bar 25 is connected to the engaging end portion 43B of the engaging member 40. With this configuration, the end portion 25D of the second reinforcing bar 25 is fixed to the floor support portion 30.
[0058] (1-5) In the foundation 10 of the building, the engaging end 43B of the engaging member 40 protrudes from the rising portion 13, and the end 25D of the second reinforcing bar 25 extends in the same direction as the engaging end 43B of the engaging member 40. With this configuration, the end 25D of the second reinforcing bar 25 and the engaging end 43B of the engaging member 40 can be easily connected.
[0059] (1-6) In the foundation 10 of the building, the engaging end 43B of the engaging member 40 has a male thread, the end 25D of the second reinforcing bar 25 has a male thread, and the engaging end 43B of the engaging member 40 and the end 25D of the second reinforcing bar 25 are connected by a nut 62 having a female thread. With this configuration, the end 25D of the second reinforcing bar 25 and the engaging end 43B of the engaging member 40 can be easily connected by the nut 62.
[0060] (1-7) In the foundation 10 of the building, the engaging member 40 of the rising portion 13 extends along the width direction of the rising portion 13, the engaging end 43B of the engaging member 40 protrudes from a recess 48 provided on the side surface 13A of the rising portion 13, the floor portion 21 is connected to the side surface 13A of the rising portion 13, and the second reinforcing bar 25 of the floor portion 21 is connected to the engaging end 43B of the engaging member 40. With this configuration, the length of the engaging end 43B that protrudes from the side surface 13A of the rising portion 13 can be shortened, so corrosion of the connection portion, which is the part where the end 25D of the second reinforcing bar 25 and the engaging end 43B of the engaging member 40 are connected, can be prevented.
[0061] (1-8) In the foundation 10 of the building, the engaging member 40 is composed of components of a separator 41 that separates the two formwork used to form the rising portion 13. With this configuration, the components of the separator 41 can be used as the engaging member 40.
[0062] (1-9) In the foundation 10 of the building, the bottom surface at the end of the floor slab 21 slopes downward from the floor slab 21 toward the rising section 13. With this configuration, corrosion of the metal members placed in the floor slab support section 30 can be reduced by the concrete.
[0063] (1-10) The construction method 50 for the foundation 10 of a building includes: a first step of installing formwork 51 and formwork 53 in the ground trench 4; a second step of arranging reinforcing bars 24 and 25 and engaging members 40 as floor slab receiving parts 30 in the formwork 51 and formwork 53; a third step of forming a rising part 13 by filling the formwork 51 and formwork 53 with cement; a fourth step of exposing the engaging end 43B of the engaging member 40 from the side surface 13A of the rising part 13; a fifth step of connecting the second reinforcing bar 25 of the first reinforcing bars 24 and second reinforcing bars 25 that constitute the floor slab skeleton part 23 to the engaging end 43B; a sixth step of backfilling the ground trench 4 with soil 5; a seventh step of arranging the first reinforcing bar 24; and an eighth step of pouring cement for forming the floor slab part 21. With this configuration, a foundation 10 that can suppress the settlement of the floor slab part 21 can be formed.
[0064] <Second Embodiment> The foundation 10 of the building according to the second embodiment will be described with reference to Figures 9 and 10. In this embodiment, components common to the first embodiment are denoted by the same reference numerals as in the first embodiment, and the description of redundant components is omitted.
[0065] [Foundation of the building] As shown in Figure 9, the second embodiment differs from the first embodiment in that the upper surface 13B of the rising section 13 is lower than the lower surface 21B of the floor section 21, and the floor support section 30 is positioned on the upper surface 13B of the rising section 13 instead of the side surface 13A. The floor section 21 is connected to the upper surface 13B of the rising section 13.
[0066] The trench section 4 is the trench portion between the second ground area 3 and the foundation section 11, and is backfilled so that the upper surface 13B of the rising section 13 is not buried by the soil 5. Specifically, the upper surface 5A and the inclined surface 5C, which slopes downward from the end 5B on the rising section 13 side of the upper surface 5A toward the rising section 13 and reaches the end 13C of the rising section 13, are backfilled with soil 5. The upper surface 5A is located at the same height as the upper surface 3A of the second ground area 3.
[0067] [Floor support section] As shown in Figure 9, the floor frame section 23 has a first reinforcing bar 24 that supports the floor section 21 and a second reinforcing bar 25 that connects to the floor support section 30. The first reinforcing bar 24 is positioned at the vertical center of the flat section of the floor section 21 in order to support the floor section 21. The end 25D of the second reinforcing bar 25 is connected to the floor support section 30. The second reinforcing bar 25 includes a vertical section 25E, an inclined section 25B, and a second horizontal section 25C.
[0068] The vertical portion 25E of the second reinforcing bar 25 is positioned to extend vertically from the upper surface 13B of the rising portion 13. However, it is not limited to this, and may be positioned to extend inclined from the upper surface 13B of the rising portion 13.
[0069] The inclined portion 25B of the second reinforcing bar 25 is positioned to extend upward parallel to the inclined surface 5C. The inclined portion 25B is separated from the inclined surface 5C. The inclined portion 25B intersects with the first reinforcing bar 24 above the inclined surface 5C. At the point of intersection, the second reinforcing bar 25 is bent again so that it is parallel to the first reinforcing bar 24.
[0070] The second horizontal portion 25C of the second reinforcing bar 25 has an overlapping portion with the first reinforcing bar 24 within the floor slab framework 23. At the overlapping portion of the first reinforcing bar 24 and the second reinforcing bar 25, the first reinforcing bar 24 and the second reinforcing bar 25 are joined together. In one example, they are joined with wire or the like.
[0071] [Fixing structure using engaging members] The fixing structure between the rising portion 13 and the second reinforcing bar 25 using engaging members 40 will be described with reference to Figures 9 and 10.
[0072] The floor support portion 30 has an engaging member 40. The engaging member 40 has an engaging body portion 43 and an engaging end portion 43C. The engaging member 40 of the rising portion 13 extends along the vertical direction.
[0073] The engaging body portion 43 is embedded in the rising portion 13. The engaging end portion 43C is exposed from the rising portion 13. The vertical portion 25E of the second reinforcing bar 25 has an end portion 25D on the upper surface 13B side of the rising portion 13. The end portion 25D of the second reinforcing bar 25 is connected to the engaging end portion 43C of the engaging member 40. In other words, the second reinforcing bar 25 of the floor portion 21 is connected to the engaging end portion 43C of the engaging member 40.
[0074] The engaging end 43C of the engaging member 40 protrudes from the upper surface 13B of the rising portion 13. In one example, it protrudes vertically. The vertical portion 25E of the second reinforcing bar 25 is positioned to extend perpendicularly toward the upper surface 13B of the rising portion 13, so its end 25D extends vertically. Therefore, the end 25D of the second reinforcing bar 25 extends vertically, in the same direction as the engaging end 43C of the engaging member 40.
[0075] The engaging end 43C of the engaging member 40 has a male thread. The end 25D of the second reinforcing bar 25 also has a male thread. The engaging end 43C of the engaging member 40 and the end 25D of the second reinforcing bar 25 are connected by a nut 62 having a female thread.
[0076] As shown in Figures 9 and 10, in this embodiment, the engaging member 40 is composed of an additional anchor bolt 42 extending in the vertical direction. The engaging member 40 is one of the components of the additional anchor bolt 42. The additional anchor bolt 42 comprises an engaging body portion 43 and an engaging end portion 43C that constitute the engaging member 40.
[0077] The second reinforcing bar 25 is connected to the engaging member 40. This allows the second reinforcing bar 25 to be fixed to the upper surface 13B of the rising section 13. In this embodiment, the second reinforcing bar 25 is connected to the additional anchor bolt 42, which is the engaging member 40. The engaging end 43C of the engaging member 40 of the additional anchor bolt 42 and the end 25D of the second reinforcing bar 25 are fastened together by a nut 62. With this structure, the second reinforcing bar 25 is fixed to the upper surface 13B of the rising section 13. At this time, the bottom surface of the end of the floor section 21 on the rising section 13 side slopes downward from the floor section 21 toward the rising section 13.
[0078] [Construction Method for Building Foundations] The construction method 50 for the building foundation 10 will be explained with reference to Figure 9. In this construction method 50, components common to the first embodiment are denoted by the same reference numerals as in the first embodiment, and the explanation of redundant components is omitted. This construction method 50 differs from the first embodiment in that it includes steps 2A to 5A instead of steps 2 to 6.
[0079] Step 1A is the same as Step 1. In Step 2A, in order to increase the strength of the foundation 11, reinforcing bars 54 are placed inside the base formwork 51 and the rising formwork 53, as in Figure 5. Furthermore, additional anchor bolts 42, which are engaging members 40 that serve as floor support parts 30, are placed inside the two rising formwork 53.
[0080] In step 3A, the rising portion 13 is formed by filling the formwork 51 and formwork 53 with cement so that the engaging end 43C of the engaging member 40 is exposed from the upper surface 13B of the rising portion 13. Specifically, after the cement poured in step 3A has hardened, the additional anchor bolts 42 are embedded in the upper surface 13B of the rising portion 13. The engaging end 43C of the embedded additional anchor bolts 42 protrudes from the upper surface 13B of the rising portion 13.
[0081] In step 4A, soil 5 is backfilled into the trench 4. During the backfilling process, soil 5 is returned to the trench 4 so that a predetermined thickness is filled in one backfilling step. After one backfilling step is completed, the backfilled soil 5 is compacted. Compaction is performed to solidify the backfilled soil 5. The trench 4 is the groove portion between the second ground area 3 and the rising section 13, and is backfilled so that the upper surface 13B of the rising section 13 is not filled with soil 5. Specifically, the upper surface 5A and the inclined surface 5C, which slopes downward from the end 5B on the rising section 13 side of the upper surface 5A toward the end 13C of the rising section 13, are backfilled with soil 5.
[0082] In step 5A, the second reinforcing bar 25, one of the first reinforcing bars 24 and second reinforcing bars 25 that constitute the floor slab frame 23, is connected to the engaging end 43C. Since the engaging end 43C of the additional anchor bolt 42 has a male thread, a nut 62 is fastened to the engaging end 43C of the engaging member 40 of the additional anchor bolt 42. Furthermore, the end 25D of the second reinforcing bar 25, which has a male thread, is screwed into the female thread portion of the nut 62 on the opposite side to where the engaging end 43C is connected. This fixes the second reinforcing bar 25 to the engaging end 43C located on the upper surface 13B of the rising portion 13.
[0083] The second reinforcing bar 25 is bent between the vertical portion 25E and the inclined portion 25B, and between the inclined portion 25B and the second horizontal portion 25C. This forms the second reinforcing bar 25 having the vertical portion 25E, the inclined portion 25B, and the second horizontal portion 25C. The second reinforcing bar 25 may be bent at these two points in advance before screwing it into the nut 62, or it may be bent after screwing it into the nut 62.
[0084] Step 6A is the same as step 7. Step 7A is the same as step 8. [Effects of the second embodiment] The effects of the second embodiment will be explained.
[0085] (2-1) In the foundation 10 of the building, the engaging member 40 of the rising portion 13 extends along the vertical direction, the engaging end 43C of the engaging member 40 protrudes from the upper surface 13B of the rising portion 13, the floor portion 21 is connected to the upper surface 13B of the rising portion 13, and the second reinforcing bar 25 of the floor portion 21 is connected to the engaging end 43C of the engaging member 40. With this configuration, the end 25D of the second reinforcing bar 25 is fixed to the floor receiving portion 30.
[0086] (2-2) In the foundation 10 of the building, the engaging member 40 is made up of additional anchor bolts 42 that extend in the vertical direction. With this configuration, the floor slab 21 can be supported by the rising portion 13 that supports the floor slab 21 from below.
[0087] (2-3) The construction method 50 for the foundation 10 of a building includes: a first step of installing formwork 51 and formwork 53 in the ground trench 4; a second step of arranging reinforcing bars 24 and 25 and an engaging member 40 as a floor slab support 30 inside the formwork 51 and formwork 53; a third step of forming a rising portion 13 by filling cement inside the formwork 51 and formwork 53 so that the engaging end 43C of the engaging member 40 is exposed from the upper surface 13B of the rising portion 13; a fourth step of backfilling soil 5 into the ground trench 4; a fifth step of connecting the second reinforcing bar 25 of the first reinforcing bars 24 and second reinforcing bars 25 that constitute the floor slab skeleton 23 to the engaging end 43C; a sixth step of arranging the first reinforcing bar 24; and a seventh step of pouring cement for forming the floor slab 21. With this configuration, a foundation 10 that can suppress the settlement of the floor slab 21 can be formed.
[0088] <Modifications> The above embodiment is an example of possible forms of the building foundation 10 and the construction method 50 for the building foundation 10, and is not intended to limit their form. The building foundation 10 and the construction method 50 for the building foundation 10 may take forms different from those exemplified in the above embodiment. Examples include forms in which a part of the configuration of the embodiment is replaced, modified, or omitted, or forms in which a new configuration is added to the embodiment. Modifications of the embodiment are shown below.
[0089] The upper surface 21A of the floor area 21 may be higher than the upper surface 2A of the first ground area 2. For example, when a building is constructed on a slope, the upper surface 21A of the floor area 21 may be higher than the upper surface 2A of the first ground area 2.
[0090] The floor area 21 may be provided not only in the portion on the second ground area 3 side of the ground trench 4, but also in the portion on the first ground area 2 side. For example, a floor area 21 for facilities such as an outdoor terrace or a water heater storage area may be located in the first ground area 2. In this case, the floor area 21 for facilities is formed to connect to a floor support portion 30 provided on the outside of the rising portion 13. The floor support portion 30 provided on the outside of the rising portion 13 has a structure similar to the floor support portion 30 of the first embodiment.
[0091] In the first embodiment, the second reinforcing bar 25 was composed of a first horizontal portion 25A, an inclined portion 25B, and a second horizontal portion 25C. However, in another example, the second reinforcing bar 25 may have a crank shape composed of a first horizontal portion, a vertical portion, and a second horizontal portion.
[0092] In the second embodiment, the second reinforcing bar 25 was composed of a vertical portion 25E, an inclined portion 25B, and a second horizontal portion 25C. However, in another example, the second reinforcing bar 25 may have an inverted L-shape composed of a vertical portion and a second horizontal portion.
[0093] This specification discloses the following technology: [Appendix 1] Appendix 1 is a foundation for a building. The foundation comprises a vertically extending rising section and a floor section connected to the rising section. The rising section has a floor support section embedded in the rising section. The floor section has a floor slab frame section that supports the floor section. The floor slab frame section is connected to the floor support section.
[0094] [Note 2] In the foundation described in Note 1, the portion where the floor slab framework and the floor slab support are connected is covered with concrete.
[0095] [Note 3] In the foundation described in Note 2, the floor slab framework has a first reinforcing bar that supports the floor slab and a second reinforcing bar that connects to the floor slab support. The end of the second reinforcing bar is connected to the floor slab support.
[0096] [Note 4] In the foundation described in Note 3, the floor support portion has an engaging member. The engaging member has an engaging end that is exposed from the rising portion. The end of the second reinforcing bar is connected to the engaging end of the engaging member.
[0097] [Note 5] In the foundation described in Note 4, the engaging end of the engaging member protrudes from the rising portion. The end of the second reinforcing bar extends in the same direction as the engaging end of the engaging member.
[0098] [Note 6] In the foundation described in Note 5, the engaging end of the engaging member has a male thread. The end of the second reinforcing bar has a male thread. The engaging end of the engaging member and the end of the second reinforcing bar are connected by a nut having a female thread.
[0099] [Note 7] In the foundation described in Note 4, the engaging member of the rising portion extends along the width direction of the rising portion. The engaging end of the engaging member protrudes from a recess provided on the side surface of the rising portion. The floor portion is connected to the side surface of the rising portion. The second reinforcing bar of the floor portion is connected to the engaging end of the engaging member.
[0100] [Note 8] In the foundation described in Note 7, the engaging member is composed of separator components that separate the two formwork used to form the rising portion.
[0101] [Note 9] In the foundation described in Note 4, the engaging member of the rising portion extends along the vertical direction. The engaging end of the engaging member protrudes from the upper surface of the rising portion. The floor portion is connected to the upper part of the rising portion. The second reinforcing bar of the floor portion is connected to the engaging end of the engaging member.
[0102] [Note 10] In the foundation described in Note 9, the engaging member is composed of additional anchor bolts extending in the vertical direction.
[0103] [Note 11] In the foundation described in any one of Notes 1 to 10, the bottom surface at the end of the floor area slopes downward from the floor area toward the rising section.
[0104] [Note 12] Note 12 is a method for constructing the foundation. The method for constructing the foundation includes: a first step of setting up formwork in the ground trench; a second step of arranging reinforcing bars and engaging members as floor slab support parts within the formwork; a third step of forming a rising section by filling the formwork with cement; a fourth step of exposing the engaging end of the engaging member from the side of the rising section; a fifth step of connecting the second reinforcing bar, one of the first and second reinforcing bars constituting the floor slab framework, to the engaging end; a sixth step of backfilling the ground trench with soil; a seventh step of arranging the first reinforcing bar; and an eighth step of pouring cement for forming the floor slab.
[0105] [Note 13] Note 13 is a method for constructing the foundation. The method for constructing the foundation includes a first step of setting up formwork in the ground trench, a second step of arranging reinforcing bars and engaging members as floor slab support parts within the formwork, a third step of forming the rising part by filling the formwork with cement so that the engaging ends of the engaging members are exposed from the upper surface of the rising part, a fourth step of backfilling the ground trench with soil, a fifth step of connecting the second reinforcing bar, one of the first and second reinforcing bars constituting the floor slab framework, to the engaging end, a sixth step of arranging the first reinforcing bar, and a seventh step of pouring cement for forming the floor slab.
[0106] 1...Ground, 2...First ground area, 2A...Top surface, 3...Second ground area, 3A...Top surface, 3B...End, 4...Ground trench section, 5...Soil, 5A...Top surface, 5B...End, 5C...Inclined surface, 5D...Bottom, 5E...End, 6...Crushed stone, 10...Foundation, 11...Foundation section, 12...Base section, 13...Rising section, 13A...Side, 13B...Top surface, 21...Floor slab section, 21A...Top surface, 22...Floor slab end, 23...Floor slab framework section, 24...First reinforcing bar, 25...Second reinforcing bar, 25A...First horizontal section, 25B...Inclined section, 25C...Second horizontal section, 25D...End, 25E...Vertical section, 30...Floor slab support section, 40...Engaging member, 4 1...Separator, 42...Additional anchor bolt, 43...Engaging body part, 43A...First engaging end, 43B...Second engaging end, 43C...Engaging end, 44...Attached member, 44A...Cover part, 44B...Protruding shaft, 45...First formwork engaging part, 45A...Clamping part, 45B...Shaft connection part, 46...Second formwork engaging part, 46A...Connection part, 46B...Clamping part, 46C...Extension part, 47...Retaining member, 48...Recess, 50...Construction method, 51...Base formwork, 52...Rising formwork base, 53...Rising formwork, 54...Reinforcing bar, 62...Nut, 71...Waterproofing member, 72...Insertion hole, D1...Depth direction
Claims
1. A foundation for a building, comprising a vertically extending rising section and a floor section connected to the rising section, wherein the rising section has a floor support section embedded in the rising section, the floor section has a floor slab frame section that supports the floor section, and the floor slab frame section is connected to the floor support section.
2. The foundation according to claim 1, wherein the portion connecting the floor slab framework and the floor slab support is covered with concrete.
3. The foundation according to claim 2, wherein the slab framework comprises a first reinforcing bar supporting the slab and a second reinforcing bar connected to the slab support, and the end of the second reinforcing bar is connected to the slab support.
4. The foundation according to claim 3, wherein the floor support portion has an engaging member, the engaging member has an engaging end exposed from the rising portion, and the end of the second reinforcing bar is connected to the engaging end of the engaging member.
5. The foundation according to claim 4, wherein the engaging end of the engaging member protrudes from the rising portion, and the end of the second reinforcing bar extends in the same direction as the engaging end of the engaging member.
6. The foundation according to claim 5, wherein the engaging end of the engaging member has a male thread, the end of the second reinforcing bar has a male thread, and the engaging end of the engaging member and the end of the second reinforcing bar are connected by a nut having a female thread.
7. The foundation according to claim 4 or 5, wherein the engaging member of the rising portion extends along the width direction of the rising portion, the engaging end of the engaging member protrudes from a recess provided on the side surface of the rising portion, the floor portion is connected to the side surface of the rising portion, and the second reinforcing bar of the floor portion is connected to the engaging end of the engaging member.
8. The foundation according to claim 7, wherein the engaging member is composed of a separator component that separates the two formwork used to form the rising portion.
9. The foundation according to claim 4, wherein the engaging member of the rising portion extends along the vertical direction, the engaging end of the engaging member protrudes from the upper surface of the rising portion, the floor portion is connected to the upper part of the rising portion, and the second reinforcing bar of the floor portion is connected to the engaging end of the engaging member.
10. The foundation according to claim 9, wherein the engaging member is composed of additional anchor bolts extending in the vertical direction.
11. The foundation according to any one of claims 1 to 10, wherein the bottom surface at the end of the floor area slopes downward from the floor area toward the rising section.
12. A method for constructing a foundation, comprising: a first step of installing formwork in a ground trench; a second step of arranging reinforcing bars and engaging members as floor slab support parts within the formwork; a third step of forming a rising section by filling the formwork with cement; a fourth step of exposing the engaging end of the engaging member from the side of the rising section; a fifth step of connecting the second reinforcing bar, one of the first and second reinforcing bars constituting the floor slab framework, to the engaging end; a sixth step of backfilling the ground trench with soil; a seventh step of arranging the first reinforcing bar; and an eighth step of pouring cement for forming the floor slab.
13. A method for constructing a foundation, comprising: a first step of installing formwork in a ground trench; a second step of arranging reinforcing bars and engaging members as floor slab support parts within the formwork; a third step of forming the rising part by filling the formwork with cement so that the engaging ends of the engaging members are exposed from the upper surface of the rising part; a fourth step of backfilling the ground trench with soil; a fifth step of connecting the second reinforcing bar, of the first and second reinforcing bars constituting the floor slab framework, to the engaging end; a sixth step of arranging the first reinforcing bar; and a seventh step of pouring cement for forming the floor slab.