Buildings and their construction methods

Abstract

To provide a building in which at least the side wall of the building and soil-cement column type continuous wall constructed around the building are joined to each other, and in which the soil-cement column type continuous wall has a high resistance to both push-in and pull-out loads from the building, and a construction method of the building.SOLUTION: A building 200 is provided, including: at least a side wall 15 of the underground portion of a building 10 within the ground G; and a soil cement column-type continuous wall 20 placed around building 10, which are joined to each other, wherein the soil-cement column-type continuous wall 20 has a core material 40 buried inside the soil cement 30, and a concrete body 60 is placed below the core material 40.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a building and a construction method thereof.

Background Art

[0002] The retaining wall includes prefabricated sheet pile walls such as parent pile horizontal sheet pile walls and steel sheet pile walls, and site-cast walls such as column row retaining walls and continuous underground walls. The column row retaining wall includes site-cast reinforced concrete column row retaining walls, steel pipe column row retaining walls, soil cement column row retaining walls (soil cement column type continuous walls), etc.

[0003] For example, the above-mentioned soil cement column type continuous wall is a temporary structure, but there is also a form in which it is connected to the side wall of the underground part of a building that is a permanent structure, and the soil cement column type continuous wall is used as part of the foundation of the building that is a permanent structure. Thus, by using the soil cement column type continuous wall not only as a retaining wall but also as part of the foundation of the permanent structure, the structure of the foundation of the permanent structure can be made simpler. For example, the amount of concrete and the amount of steel bars in the foundation can be reduced, so that a significant reduction in construction costs can be achieved.

[0004] Here, a specific configuration of the form in which the above-mentioned soil cement column type continuous wall is used as part of the foundation of a building that is a permanent structure will be described with reference to FIGS. 1 and 2. FIG. 1 is a longitudinal sectional view showing an example of a building, and FIG. 2 is a view taken along the line II-II of FIG. 1.

[0005] The building 100 in the illustrated example is configured by joining the side wall 15 and the chassis 17 of the underground part 11 of the building 10 in the ground G and the soil cement column type continuous wall 20 constructed around the building 10. For example, a soil cement column type continuous wall 20 in the shape of a rectangular frame in plan view is constructed around the side wall 15 of the underground part 11 of the building 10 having a rectangular shape in plan view, and the two are joined at a plurality of locations. FIG. 1 shows only a part of the side wall 15, the chassis 17, and the column 16 of the building 10.

[0006] The soil-cement column-type continuous wall 20 is constructed such that parts of the circular soil-cement 30 overlap each other in plan view, and a core material 40 made of H-shaped steel is embedded inside the soil-cement 30 within the circular borehole G1 in plan view. The core material 40 has a web 41, a first flange 42 on the building 10 side, and a second flange 43 on the opposite side of the building 10.

[0007] Of the core material 40 embedded in the soil cement 30, multiple stud dowels 50 are joined to the upper first flange 42 on the building 10 side by welding or the like, causing them to protrude laterally. The protruding stud dowels 50 are embedded in the side wall 15 and base 17 of the underground section 11, thereby integrating the building 10 with the soil cement column-type continuous wall 20. The weight of the building 10 and the compressive forces generated when the building is displaced during an earthquake are transmitted from the building 10 to the core material 40 via the stud dowels 50 as a compressive load N1.

[0008] Below the web 41 of the core material 40, multiple stud dowels 45 are joined by welding or the like, protruding laterally from the web 41 and embedded inside the soil cement 30. Against the compressive load N1 transmitted to the core material 40, the bearing capacity of the soil cement column-type continuous wall 20 is ensured by the tip bearing capacity, which is determined by the tip area A1 of the tip of the core material 40 and the N value of the ground surrounding the tip, the bearing pressure from each stud dowel 45, and the frictional force between the soil cement 30 and the ground G (or the frictional force between the core material 40 and the soil cement 30).

[0009] However, the surface of the core material 40 is smooth, the frictional force between the core material 40 and the soil cement 30 is small, and as shown in Figure 2, the tip area A1 of the core material 40, which is made of H-shaped steel, is small even when compared to the total area of ​​the soil cement column-type continuous wall 20, and therefore it is difficult to expect a large tip bearing capacity. For these reasons, there is room for improvement in the bearing capacity (support performance) against compressive loads in the soil cement column-type continuous wall 20.

[0010] On the other hand, in a configuration where the soil-cement column-type continuous wall 20 is used as part of the foundation of the permanent structure, when a horizontal force acts on the building 10 during an earthquake, causing the building 10 to displace, and this displacement generates a pull-out force N2 (pull-out load) on the building 10, this pull-out load N2 is also transmitted to the core material 40 via the stud dowels 50. At this time, the rod-shaped stud dowels 45 attached below the core material 40 cannot be expected to provide significant pull-out resistance, and considering that the frictional force between the soil cement 30 and the core material 40 is small as described above, there is a risk that the core material 40 may be pulled out from the soil cement 30.

[0011] As explained above, while using soil-cement continuous column walls as part of the foundation of a permanent structure can significantly reduce construction costs, conventional soil-cement continuous column walls have room for improvement in terms of resistance to compressive and tensile loads acting from the permanent structure. Therefore, there is a need for buildings equipped with soil-cement continuous column walls that have high resistance to both compressive and tensile loads.

[0012] In Patent Document 1, a soil-cement wall is proposed for use as shoring after the completion of the first-floor construction in a construction method using the top-down construction method, and which bears a portion of the weight of the main structure. In this soil-cement wall, the surface of the core material embedded in the soil-cement is provided with irregularities or stud dowels, thereby providing a means for adhesion between the core material and the soil-cement. [Prior art documents] [Patent Documents]

[0013] [Patent Document 1] Japanese Patent Application Publication No. 11-303062 [Overview of the project] [Problems that the invention aims to solve]

[0014] Even in the soil cement wall described in Patent Document 1, as explained with reference to Figures 1 and 2 above, since only stud dowels are attached to the core material, it is difficult to say that it has sufficient resistance to compressive and tensile loads acting from the permanent structure.

[0015] The present invention has been made in view of the above problems, and aims to provide a building equipped with a soil-cement columnar continuous wall that has high resistance to both compressive and tensile loads acting from the building, in a building in which at least the side walls of the building and soil-cement columnar continuous walls constructed around the building are joined together. [Means for solving the problem]

[0016] To achieve the aforementioned objective, one aspect of the building according to the present invention is: A building in which at least the side walls of the underground portion of the building located within the ground are joined to a continuous soil-cement column wall provided around the building, and the continuous soil-cement column wall has a core material embedded inside the soil cement, A concrete body is provided below the core material, which is a distinguishing feature.

[0017] According to this embodiment, a concrete body is provided below the core material constituting the soil-cement column-type continuous wall, which is located in the ground and joined to at least the side walls of the underground portion of the building. This allows the concrete body, which has a larger tip area than the core material formed by, for example, H-shaped steel, to increase the tip bearing capacity of the core material, resulting in a soil-cement column-type continuous wall with high support performance against compressive loads acting from the building. Furthermore, with concrete bodies of various three-dimensional shapes, such as rectangular parallelepipeds, polygonal bodies, and cylindrical bodies, when an uplift load is applied to the concrete body through the core material, the upper surface of the concrete body protruding laterally from the core material receives resistance from the soil cement above, thereby improving the uplift resistance of the concrete body, and as a result, the resistance of the core material to uplift loads is also improved.

[0018] Here, the phrase "at least the side walls of the building" includes both the side walls (underground part) of the building and both the side walls and the chassis.

[0019] Another aspect of the building according to the present invention is characterized in that the planar dimension of the concrete body is larger than the planar dimension of the core material.

[0020] According to this aspect, since the end face area of the concrete body is larger than the end face area of the core material, the end support force of the core material can be increased. Here, the end face area of the concrete body can be expanded up to an area that is, for example, close to the area of the surrounding soil cement at maximum.

[0021] Another aspect of the building according to the present invention is characterized in that the concrete body is a precast concrete member that is installed before being embedded in the soil cement with respect to the core material.

[0022] According to this aspect, since the concrete body is a precast concrete member that is installed before being embedded in the soil cement with respect to the core material, a high-quality concrete body can be surely installed on the core material, the construction of embedding the core material provided with the concrete body into the soil cement also becomes good, and a great deal of labor for constructing the concrete body by in-situ concrete can be eliminated.

[0023] Another aspect of the building according to the present invention is a first stud dowel is attached to the core material, characterized in that the first stud dowel is embedded inside the concrete body.

[0024] According to this aspect, since the first stud dowel attached to the core material is embedded inside the concrete body, the bonding strength between the core material and the concrete body can be increased. That is, both the pushing load and the pulling load acting from the core material can be effectively transmitted to the concrete body by the bearing pressure and shear force of the first stud dowel. For example, in a form where the core material is simply embedded inside the concrete body, there is a risk that the core material may be pulled out from the concrete body when a pulling load acts.

[0025] Moreover, another aspect of the building according to the present invention is characterized in that unevenness is provided on the surface of the concrete body.

[0026] According to this aspect, unevenness is provided on the surface of the concrete body, and soil cement enters into this unevenness, so that the frictional force (peripheral frictional force) between the concrete body and the surrounding soil cement increases, and the supporting force of the core material including the concrete body can be further increased.

[0027] Moreover, another aspect of the building according to the present invention is characterized in that a second stud dowel is joined above the core material, and the second stud dowel is embedded in the side wall of the underground part, whereby the side wall and the soil cement columnar continuous wall are joined.

[0028] According to this aspect, the second stud dowel provided above the core material is embedded in the side wall of the underground part, and the side wall and the soil cement columnar continuous wall are joined, so that the pushing load and the pulling load acting from the building can be effectively transmitted to the core material via the second stud dowel, and it becomes possible to bear both the pushing load and the pulling load by the soil cement columnar continuous wall including the core material.

[0029] Moreover, one aspect of the construction method of the building according to the present invention is A construction method for a building, wherein at least the side walls of the underground portion of the building located within the ground are joined to a continuous soil-cement column wall provided around the building, Step A involves constructing a continuous soil-cement column wall by installing a core material, formed from an H-shaped steel beam comprising a first flange on the building side, a second flange on the opposite side of the building, and a web, into the soil-cement inside the borehole. Step B involves cutting the soil cement at the upper end of the soil cement column-type continuous wall to expose a portion of the first flange, and joining the second stud dowel to the exposed portion of the first flange. The process includes step C, in which at least the side wall of the underground section and the soil-cement columnar continuous wall are joined together by constructing the side wall of the building that is in contact with at least the first flange and embedding the second stud dowel in the side wall, In step A, a concrete body is installed below the core material when erecting the core material.

[0030] According to this embodiment, in step A of constructing a soil-cement columnar continuous wall, when installing a core material into the soil-cement filled in the borehole, by installing a core material with a concrete body pre-installed below it, a soil-cement columnar continuous wall with high resistance to both compressive and tensile loads acting from the building, and a building equipped with this soil-cement columnar continuous wall, can be efficiently constructed.

[0031] Furthermore, other embodiments of the construction method for buildings according to the present invention are: The concrete body is characterized in that the tip area is larger than the tip area of ​​the core material.

[0032] According to this embodiment, the tip area of ​​the concrete body is larger than the tip area of ​​the core material, thereby increasing the tip bearing capacity of the core material. [Effects of the Invention]

[0033] As can be understood from the above explanation, the present invention provides a building and its construction method in which at least the side walls of the building and the soil-cement columnar continuous wall constructed around the building are joined, and provides a building equipped with a soil-cement columnar continuous wall that has high resistance to both compressive loads and tensile loads acting from the building. [Brief explanation of the drawing]

[0034] [Figure 1] This is a longitudinal cross-sectional view showing an example of a conventional building. [Figure 2] This is a view along the line II-II in Figure 1. [Figure 3] This is a longitudinal cross-sectional view showing an example of a building according to the embodiment, and a diagram illustrating step C of an example of a construction method for the building according to the embodiment. [Figure 4] This is a view taken along the line IV-IV in Figure 3, which is a cross-sectional view of the concrete body cut midway. [Figure 5] This is a schematic diagram illustrating the tip bearing capacity and pull-out resistance of a concrete body. [Figure 6] This diagram illustrates step A of an example of a construction method for a building according to this embodiment. [Figure 7] This diagram illustrates step B of an example of a construction method for a building according to the embodiment. [Modes for carrying out the invention]

[0035] The building and its construction method according to the embodiment will be described below with reference to the attached drawings. In this specification and the drawings, substantially identical components may be denoted by the same reference numerals to avoid redundant explanations.

[0036] [Buildings according to the embodiment] First, an example of a building according to the embodiment will be described with reference to Figures 3 to 5. Here, Figure 3 is a longitudinal section view showing an example of a building according to the embodiment, Figure 4 is a view taken along the line IV-IV in Figure 3, which is a cross-sectional view taken by cutting the concrete body in the middle, and Figure 5 is a schematic diagram illustrating the tip bearing capacity and pull-out resistance of the concrete body. Figure 3 also illustrates step C of an example of the construction method for the building according to the embodiment, and will be referred to when describing the construction method in detail below.

[0037] The illustrated building 200 is constructed by connecting the side walls 15 and base 17 of the underground section 11 of the building 10 located in the ground G with the soil-cement columnar continuous wall 20 constructed around the building 10. For example, around the side walls 15 of the underground section 11 of the building 10, which is rectangular in plan view, a soil-cement columnar continuous wall 20 in the shape of a rectangular frame in plan view is constructed, and the two are joined at multiple points. The plan view shape of the building 10 varies, and the soil-cement columnar continuous wall 20 is constructed in a frame shape corresponding to the plan view shape of the building 10.

[0038] Building 10 may be made of RC (Reinforced Concrete), S (Steel), SRC (Steel Reinforced Concrete), or a hybrid of these structures. Building 10 can take many forms, including office buildings, apartment buildings, gymnasiums, shopping malls, and various public buildings. In the illustrated examples below, the building will be described as having at least the side walls 15 and base 17 of the underground section 11 made of RC.

[0039] On the other hand, the soil-cement column-type continuous wall 20 is constructed such that parts of the circular soil-cement 30 overlap each other in plan view, and a core material 40 formed of H-shaped steel is embedded inside the soil-cement 30 within the circular borehole G1 in plan view. Here, in addition to H-shaped steel, steel sheet piles or precast concrete products may also be used as the core material.

[0040] Soil cement 30 is prepared by mixing and stirring soil generated by excavating the ground G with cement grout discharged from the tip of a multi-screw mixing auger machine or the like (not shown), and is constructed by inserting a core material 40 into the soil cement before it hardens.

[0041] The soil-cement column-type continuous wall 20 shown in the illustration serves as a retaining wall during the construction of the building 10, and after the building 10 is constructed, it is joined to the underground section 11 of the building 10, thereby functioning as the foundation of the building 10.

[0042] Of the core material 40 embedded in the soil cement 30, multiple second stud dowels 50 are welded to the first flange 42 on the building 10 side above, causing them to protrude laterally. The protruding second stud dowels 50 are embedded in the side wall 15 and base 17 of the underground section 11, thereby integrating the building 10 with the soil cement column-type continuous wall 20.

[0043] In the soil-cement column-type continuous wall 20, a concrete body 60 is integrally provided below the core material 40 embedded in the soil-cement 30, and the concrete body 60 is also embedded inside the soil-cement 30.

[0044] Although the concrete body 60 in the illustrated example has a rectangular prism shape, various other three-dimensional concrete shapes such as polygonal prisms, cylinders, and elliptical prisms can also be used.

[0045] As shown in Figure 4, multiple (eight in total, four on each side in the illustrated example) first stud dowels 47 are welded to both wide surfaces of the web 41 below the core material 40. Here, reinforcing bars surrounding the core material 40 and reinforcing bars extending longitudinally into the core material 40 may be embedded inside the concrete body 60.

[0046] Multiple first stud dowels 47 that protrude laterally from the web 41 of the core material 40 are embedded in the concrete body 60, thereby increasing the unity between the core material 40 and the concrete body 60. This eliminates concerns that the core material 40 may be pulled out or pushed out of the concrete body 60 when a compressive load N1 or pull-out resistance force N2 acts from the core material 40 to the concrete body 60.

[0047] The concrete body 60 is a precast concrete member that is attached to the core material 40 in advance when the core material 40 is erected in the soil cement 30.

[0048] As can be clearly seen from Figure 4, the cross-sectional area A2 (tip area) of the concrete body 60 is set to be significantly larger than the cross-sectional area (tip area) of the core material 40 made of H-shaped steel. In the concrete body 60 shown in the example, its tip area A2 is set to be close to the tip area of ​​the surrounding soil cement 30.

[0049] As described above, because a concrete body 60 with a large tip area A2 is integrally provided below the core material 40, the tip bearing capacity of the core material 40 is calculated using the tip area A2 of the lower surface 63 of the concrete body 60 and the uniaxial compressive strength of the surrounding soil cement 30, as shown in Figure 5. Therefore, the tip bearing capacity R1 of the core material 40 can be significantly increased compared to, for example, the tip area A1 of the core material 40 shown in Figure 2.

[0050] This makes it possible to increase the load-bearing capacity of the soil-cement columnar continuous wall 20, including the core material 40, against the compressive load N1 transmitted from the building 10 to the core material 40 via the second stud dowel 50.

[0051] On the other hand, as shown in Figure 5, since the concrete body 60 protrudes laterally from the core material 40 below the core material 40, the upper surface 62 of the concrete body 60 receives a pull-out resistance force R2 from the upper soil cement 30 against the pull-out load N2 transmitted from the building 10 to the core material 40 via the second stud dowel 50. Therefore, it is possible to increase the load-bearing capacity of the soil cement column-type continuous wall 20 including the core material 40 against the acting pull-out load N2.

[0052] Although not shown in the diagram, the side surface 61 of the concrete body 60 may have numerous irregularities. These irregularities can be formed by roughening the surface 61, or by creating irregularities on the inner surface of the formwork when filling the formwork with concrete to construct the concrete body 60 below the core material 40.

[0053] The presence of numerous irregularities on the side surface 61 of the concrete body 60 increases the frictional force between the concrete body 60 and the surrounding soil cement 30, thereby further enhancing the bearing capacity of the core material, including the concrete body.

[0054] [Construction method for a building according to this embodiment] Next, an example of a construction method for a building according to the embodiment will be described with reference to Figures 6 and 7 and Figure 3. Here, Figures 6 and 7 are diagrams illustrating steps A and B of the example of a construction method for a building according to the embodiment, respectively. As previously described, Figure 3 is a vertical cross-sectional view showing an example of a building according to the embodiment, and is a diagram illustrating step C of the example of a construction method for a building according to the embodiment.

[0055] In the construction method of the building, first, as shown in Figure 6, prior to the construction of the building, a retaining wall is constructed around the building construction area, for example, a continuous soil-cement column wall 20 in the shape of a rectangular frame in plan view.

[0056] The construction method for the soil-cement column-type continuous wall 20 can be the known SMW (Soil Mixing Wall) method, and begins with the removal of underground obstacles, followed by the installation of a guide wall (not shown), the mixing of soil-cement, and the drilling and mixing of the cement slurry of the design mix while discharging it from the tip of the auger head of a multi-screw mixing auger machine, etc. After reaching a predetermined depth, the auger head is withdrawn while repeatedly mixing is performed, thereby creating soil-cement 30 in the drilled hole G1.

[0057] Then, before the soil cement 30 hardens, the core material 40 is inserted into the soil cement 30 in the X1 direction and erected. In addition, as a wall construction procedure, a continuous method can be applied in which the first element is constructed, then the second element is constructed at an interval, and then the holes at both ends of the third element are constructed overlapping with the holes at one end of both the first and second elements. Alternatively, a pre-drilling combined method can be applied in which multiple holes are pre-drilled at intervals in positions that the holes of each element will follow, and then each element is constructed so that the holes of each element overlap with the pre-drilled holes.

[0058] When erecting the core material 40, a concrete body 60 is pre-installed as a precast concrete member below the core material 40.

[0059] Thus, because the concrete body 60 installed below the core material 40 is a precast concrete member, a high-quality concrete body 60 can be reliably installed on the core material 40, and the construction of the core material 40 with the concrete body 60 into the soil cement 30 is also improved. For example, if the concrete body is constructed using cast-in-place concrete, it will require a great deal of effort and there will be a high degree of uncertainty in terms of quality such as shape, but such construction effort and quality uncertainty are eliminated (Above, Process A).

[0060] Next, as shown in Figure 7, the upper region 30a on the building side of the soil-cement column-type continuous wall 20 is cut away to expose a portion of the first flange 42.

[0061] Next, multiple second stud dowels 50 are welded to the exposed first flange 42 (this completes step B).

[0062] Next, as shown in Figure 3, the side walls 15 and base 17 of the underground section 11 of the building 10 that are in contact with at least the second flange 43 are constructed, and multiple second stud dowels 50 are embedded in the side walls 15 and base 17, thereby joining the side walls 15 and base 17 of the underground section 11 to the soil-cement column-type continuous wall 20.

[0063] Subsequently, by constructing the entire building 10, a building 200 is constructed in which the building 10 and the soil-cement column-type continuous wall 20 are interconnected (this completes process C).

[0064] According to the illustrated construction method, in step A, when installing the core material 40 into the soil cement 30 in the borehole G1, the core material 40 has a concrete body 60 pre-installed below it. This allows for the efficient construction of a soil cement column-type continuous wall 20 with high resistance to both the compressive load N1 and the tensile load N2 acting from the building, and enables the efficient construction of a building 200 in which the soil cement column-type continuous wall 20 and the building 10 are integrated.

[0065] Other embodiments may be used in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited in any way to the configurations shown herein. In this regard, modifications can be made without departing from the spirit of the present invention, and can be appropriately determined according to the application form. [Explanation of symbols]

[0066] 10: Buildings 11: Underground 15: Side wall 16: Pillar 17: Bottom board 20: Soil-cement column-type continuous wall 30: Soil cement 30a: Upper area 40: Core material (H-beam) 41: Web 42: First flange 43: Second flange 47: First stud dowel (stud dowel) 50: Second stud dowel (stud dowel) 60: Concrete body 61: Side view 62:Top surface 63: Bottom surface 200: Buildings G: Ground G1: Drilling N1: Indentation load N2: Pull-out load R1:Tip bearing capacity R2: Pull-out resistance A2: Tip area (cross-sectional area)

Claims

1. A building in which at least the side walls of the underground portion of the building located within the ground are joined to a continuous soil-cement column wall provided around the building, and the continuous soil-cement column wall has a core material embedded inside the soil cement, The lower part of the core material, including its lower end, is embedded in a concrete body, and this concrete body is also embedded inside the soil cement. A building characterized in that the concrete body is a precast concrete member installed in relation to the core material before being embedded in the soil cement, and the tip area of ​​the concrete body is larger than the tip area of ​​the core material.

2. The first stud dowel is attached to the aforementioned core material. The building according to claim 1, characterized in that the first stud dowel is embedded inside the concrete body.

3. The building according to claim 1 or 2, characterized in that the surface of the concrete body is provided with irregularities.

4. The building according to any one of claims 1 to 3, characterized in that a second stud dowel is joined to the upper part of the core material, and the second stud dowel is embedded in the side wall of the underground section, thereby joining the side wall and the soil-cement columnar continuous wall.

5. A construction method for a building, wherein at least the side walls of the underground portion of the building located within the ground are joined to a continuous soil-cement column wall provided around the building, Step A involves constructing a continuous soil-cement column wall by installing a core material, formed from an H-shaped steel beam comprising a first flange on the building side, a second flange on the opposite side of the building, and a web, into the soil-cement inside the borehole. Step B involves cutting the soil cement at the upper end of the soil cement column-type continuous wall to expose a portion of the first flange, and joining the second stud dowel to the exposed portion of the first flange. The process includes step C, in which at least the side wall of the underground section and the soil-cement columnar continuous wall are joined together by constructing the side wall of the building that is in contact with at least the first flange and embedding the second stud dowel in the side wall, A method for constructing a building, characterized in that, in step A above, when erecting the core material, the lower part including the lower end of the core material is embedded in a concrete body whose tip area is larger than the tip area of ​​the core material, and the concrete body is also embedded inside the soil cement.

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