Building and construction method of the same

Abstract

To provide a building which can enhance a supporting force of soil cement while preventing wraparound of underground water by embedding the soil cement in a hardly permeable layer (containing impermeable layer), regarding the building in which a soil cement column row type continuous wall is joined with respect to a constitution member of an underground part of the building, and to provide a construction method of the same.SOLUTION: Constitution members 15, 17 of an underground part 11 which is in the ground G and which a building 10 includes and a soil cement column row type continuous wall 20 provided around the building 10 are joined. The building 200 includes a soil-cement column-type continuous wall 20 in which a steel core material 40 is embedded inside soil cement 30. The soil cement 30 has a lower end 35 embedded in a low-permeability layer GC, and includes a widened bottom part 30A that expands laterally above the lower end 35.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Retaining walls include prefabricated sheet pile walls such as horizontal sheet pile walls and steel sheet pile walls, and cast-in-place walls such as column-row walls and continuous underground walls. Column-row walls include cast-in-place reinforced concrete column-row walls, steel pipe column-row walls, and soil cement column-row walls (soil cement column-row continuous walls).

[0003] For example, while the above-mentioned soil cement diaphragm wall is a temporary structure, there is also a form in which the soil cement diaphragm wall is used as part of the foundation of a permanent building by being connected to the side walls of the underground portion of the building. In this way, by using the soil cement diaphragm wall not only as an earth retaining wall but also as part of the foundation of the permanent structure, the structure of the foundation of the permanent structure can be simplified, and for example, the amount of concrete and rebar in the foundation can be reduced, thereby significantly reducing construction costs. For example, Patent Document 1 proposes a method in which, when constructing the underground structure of a building after the construction of the soil cement diaphragm wall, shear connectors or the like are attached to the soil cement diaphragm wall, and the soil cement diaphragm wall and the underground structure of the building are constructed as a single unit.

[0004] Here, a specific configuration in which the above-mentioned soil cement diaphragm wall is used as part of the foundation of a building, which is a permanent structure, will be described with reference to Fig. 1. Fig. 1 is a vertical cross-sectional view showing an example of a conventional building.

[0005] The illustrated building 100 is constructed by joining the side walls 15 and foundation beams 17 of the basement 11 of the building 10, which is located in the ground G, to a soil cement diaphragm column wall 20 constructed around the building 10. Here, the ground G in the illustrated example is made up of, from top to bottom, a sand layer GA, a hard sand layer GB, and a clay layer GC, and is a construction area with a high groundwater level. For example, a soil cement diaphragm column wall 20 having a rectangular frame shape in plan view is constructed around the side walls 15 of the basement 11 of the building 10, which is rectangular in plan view, and the two are joined at multiple locations. FIG. 1 shows only the side walls 15, foundation beams 17, and columns 16 of the building 10.

[0006] The soil cement column-type continuous wall 20 is constructed by overlapping portions of the soil cement 30, which is circular in plan view, with a core material 40 made of H-shaped steel having 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, buried inside the soil cement 30 within the circular hole G1 in plan view.

[0007] Of the core material 40 embedded in the soil cement 30, a first flange 42 on the upper building 10 side has multiple shear connectors 50 joined by welding or the like and protruding laterally, and the protruding shear connectors 50 are embedded in the side walls 15 and foundation beams 17 of the underground portion 11, thereby integrating the building 10 with the soil cement diaphragm column wall 20. The weight of the building 10 and the compressive force N1 generated when the building is displaced during an earthquake are transmitted from the building 10 to the core material 40 via the shear connectors 50.

[0008] The compressive force N1 transmitted to the core material 40 is transmitted to the soil cement 30 surrounding the core material 40 via the tip and peripheral surface of the core material 40, and the compressive force N1 is transmitted to the ground G via the tip bearing force of the soil cement 30 and the peripheral friction force between the soil cement 30 and the surrounding ground G, thereby ensuring the bearing force of the soil cement diaphragm wall 20. Although not shown, there is also a configuration in which multiple shear connectors are joined by welding or the like, protrude to the sides of the web 41, and are embedded inside the soil cement 30. According to this configuration, the transmittance of the compressive force N1 to the soil cement 30 surrounding the core material 40 is further improved. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 4466418 Summary of the Invention [Problem to be solved by the invention]

[0010] Incidentally, in cases where the groundwater level is high, as in the illustrated example, the soil cement column-type continuous wall 20 is expected to have water-tight properties, but if the ground near the bottom end of the core material 40 is a permeable sand layer GA or a hard sand layer GB sand, etc., measures will be taken to extend only the soil cement 30 down to the clay layer GC, which is a low-permeability layer (or impermeable layer), and prevent groundwater from flowing around in the X1 direction.

[0011] However, since the lower end 35 of the soil cement 30 is not located in the hard sand layer GB but in the relatively soft clay layer GC, it is difficult to obtain sufficient tip bearing capacity of the soil cement 30, and there is room for improvement in terms of bearing capacity.

[0012] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a building and a construction method thereof, which is constructed by joining a soil cement continuous column wall to constituent members of the underground part of the building, and which can increase the bearing capacity of the soil cement while preventing groundwater from leaking in by embedding the soil cement in a low-permeability layer (including an impermeable layer). [Means for solving the problem]

[0013] In order to achieve the above object, one aspect of the building according to the present invention is as follows: A building in which constituent members of an underground portion of a building located in the ground are joined to a soil cement continuous column wall provided around the building, and the soil cement continuous column wall has a steel core material buried inside the soil cement, The soil cement is characterized in that its lower end is embedded in a low-permeability layer and has an expanded bottom portion that extends laterally above the lower end.

[0014] According to this aspect, the lower end of the soil cement is embedded in the impermeable layer and is provided with an expanded base extending laterally above the lower end, thereby increasing the bearing capacity of the soil cement while preventing groundwater from seeping in. As a result, in a building in which a soil cement diaphragm wall is joined to a component of the underground portion of a building, the compressive force acting on the core material from the building is supported by the bearing capacity (bearing capacity of the soil cement or total bearing capacity) resulting from the tip bearing capacity of the soil cement, the bearing capacity of the lower end of the expanded base, and the peripheral friction force between the soil cement and the surrounding ground, and the compressive force can be transmitted to the ground.

[0015] As shown in Figure 1, if there is a hard sand layer above a low-permeability layer (including an impermeable layer), providing an expanded base in the hard sand layer can provide a large bearing capacity at the bottom of the expanded base. Even if there is no hard sand layer and the ground is only a soft clay layer, providing an expanded base in the soil cement can increase the bearing capacity of the soil cement. In the latter case, where the ground is only a soft clay layer, providing multiple expanded bases midway along the soil cement's length, for example, can provide bearing capacity at the bottom of multiple expanded bases, making it possible to create soil cement with the desired bearing capacity even on soft ground.

[0016] Furthermore, examples of "constituent members of the underground portion of a building" include foundation beams, base slabs, side walls, columns, etc., of the underground portion of a building. For example, shear connectors are joined to the core material and embedded in the foundation beams, etc., of the underground portion to join the foundation beams, etc., to the soil cement diaphragm wall. Here, shear connectors include stud dowels, burring shear connectors, etc.

[0017] In another aspect of the building according to the present invention, The side view shape of the expanded bottom portion is characterized in that the lower end of the expanded bottom portion extending laterally from the soil cement is the longest, the upper end of the expanded bottom portion is on the side of the soil cement, and the line connecting the lower end and the upper end is either a straight line, a curved line, or a combination of a straight line and a curved line.

[0018] According to this embodiment, the side view shape of the expanded base is such that the length of the lower end of the expanded base is the longest, the upper end of the expanded base is on the side of the soil cement, and the line connecting the lower and upper ends is either a straight line, a curved line, or a combination of a straight line and a curved line.This makes it possible to form the expanded base using as little cement as possible as possible, while obtaining sufficient support force on the underside of the expanded base.

[0019] In another aspect of the building according to the present invention, The expanded bottom portion is characterized in that it is provided in a sand layer or hard sand layer shallower than the impermeable layer.

[0020] According to this aspect, when a sand layer or hard sand layer is present shallower than the impermeable layer, providing the expanded bottom portion in the sand layer or hard sand layer can provide a large bearing capacity at the bottom end of the expanded bottom portion, thereby increasing the bearing capacity of the soil cement. In particular, providing the expanded bottom portion in the hard sand layer can provide an even larger bearing capacity at the bottom end of the expanded bottom portion.

[0021] Another aspect of the building according to the present invention is The core material is characterized in that a linear protrusion extending in the direction of the expanded bottom portion is provided at a position corresponding to the expanded bottom portion.

[0022] According to this aspect, linear protrusions extending in the direction of the expanded base are provided at positions on the core material corresponding to the expanded base, so that the compressive force acting on the core material can be transmitted to the expanded base via the linear protrusions. Furthermore, by having the protrusions bear part of the shear force acting on the expanded base, the shear force borne by the soil cement in the expanded base can be reduced.

[0023] Another aspect of the building according to the present invention is The protrusion is a stud dowel.

[0024] According to this embodiment, since the protrusions are stud dowels, they can be easily joined to the core material by welding using commonly available stud dowels, which allows for good load transmission to the expanded portion without increasing production costs and reduces the shear force borne by the soil cement in the expanded portion.

[0025] Another aspect of the building according to the present invention is One ends of two shaft members are rotatably assembled to each other via a first rotating part at a position corresponding to the expanded bottom portion of the core material, and the other ends of the two shaft members are rotatably attached to the core material via two second rotating parts located at different vertical positions, The device is characterized in that by pulling up the wire attached to the first pivoting portion from the ground, the two shaft members expand sideways and parts of them enter the inside of the expanded bottom portion.

[0026] According to this aspect, two shaft members are rotatably assembled to the core at positions corresponding to the expanded bottom portion, and are also rotatably attached to different vertical positions of the core. When the wire is raised from the ground, the two shaft members expand laterally, partially entering the expanded bottom portion. This allows the two shaft members to close and not interfere with the installation of the core into the soil cement. Furthermore, when aligned with the expanded bottom portion, the two shaft members expand laterally, partially entering the expanded bottom portion, allowing the pressing force acting on the core to be transmitted to the expanded bottom portion via the two shaft members. Furthermore, by having the two shaft members partially bear the shear force acting on the expanded bottom portion, the shear force borne by the soil cement in the expanded bottom portion can be reduced.

[0027] The wire may be a wire, chain, a relatively strong string, etc. The wire attached to the first rotation part, which is the rotation center of the two shaft members, is passed through a guide attached in the longitudinal direction of the core member and extends to the ground, thereby ensuring good tensile strength of the wire.

[0028] In another aspect of the building according to the present invention, The lower end of the core material is located above the lower end of the soil cement, and a predetermined distance is set between the two lower ends.

[0029] According to this embodiment, the lower end of the core is positioned above the lower end of the soil cement at a predetermined distance, so that the area of ​​the lower end of the soil cement can be taken into account when calculating the tip bearing capacity. If the lower end of the core were to extend all the way to the bottom of the soil cement, the area of ​​the lower end of the core, on which the compressive force acts directly, would need to be used when calculating the tip bearing capacity, which would reduce the tip bearing capacity and the overall bearing capacity of the soil cement.

[0030] Here, the "predetermined distance" can be a length ranging from 1 m to several meters, or approximately 1.5 to 2 times the cross-sectional height of the core material (if the core material is made of H-shaped steel, the length of the web).

[0031] In addition, one aspect of the construction method for a building according to the present invention is as follows: A construction method for a building in which components of an underground portion of a building located in the ground are joined to a soil cement diaphragm wall provided around the building, Step A is to construct a soil cement column-type continuous wall by erecting a core member formed of an H-shaped steel beam having a first flange on the building side, a second flange on the opposite side of the building, and a web inside the soil cement in the drilled hole; Step B: cutting the soil cement at the upper end of the soil cement diaphragm wall to expose a portion of the first flange, and joining a stud dowel to the exposed portion of the first flange; and a step C of constructing the structural member of the building that abuts against the first flange and embedding the stud dowel in the structural member, thereby joining the structural member of the underground portion and the soil cement column-type continuous wall to each other, In the step A, The tip of the soil cement is embedded in the impermeable layer, The method is characterized in that a flared bottom portion that extends laterally is constructed above the tip of the soil cement.

[0032] According to this embodiment, by embedding the lower end of the soil cement in a low-permeability layer and constructing an expanded bottom portion extending laterally above the lower end, the bearing capacity of the soil cement can be increased while preventing groundwater from leaking in.

[0033] Here, as an example, the construction of the expanded bottom section can be carried out by using an auger head that can be rotated around a pivot axis, applying soil cement that extends to the impermeable layer, then pulling the auger head up to the construction position of the expanded bottom section, rotating the auger head sideways, and drilling and mixing the cement slurry while ejecting it from the tip of the auger head.

[0034] Another aspect of the construction method for a building according to the present invention is as follows: The enlarged bottom portion is constructed at a position corresponding to a sand layer or hard sand layer shallower than the impermeable layer.

[0035] According to this embodiment, when there is a sand layer or hard sand layer shallower than the impermeable layer, by constructing the expanded bottom portion in the sand layer or hard sand layer, a large bearing capacity can be obtained at the lower end of the expanded bottom portion, and the bearing capacity of the soil cement can be increased. [Effects of the Invention]

[0036] As can be understood from the above explanation, according to the building and construction method of the present invention, in a building in which a soil cement column-type continuous wall is joined to the constituent members of the underground part of the building, the soil cement can be embedded in the impermeable layer to prevent groundwater from leaking in, while increasing the bearing capacity of the soil cement. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 is a vertical cross-sectional view showing an example of a conventional building. [Figure 2] FIG. 2 is a longitudinal cross-sectional view showing an example of a building according to an embodiment, and is also a diagram illustrating step C of an example of a construction method for a building according to an embodiment. [Figure 3] FIG. 10 is a vertical cross-sectional view of another example of the expanded bottom portion. [Figure 4] FIG. 2 is a diagram illustrating step A of an example of a construction method for a building according to an embodiment. [Figure 5] 4, and is a diagram illustrating step A of an example of the construction method for a building according to the embodiment. [Figure 6] 5, is a diagram illustrating steps A and B of an example of a construction method for a building according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0038] Hereinafter, a building and a construction method thereof according to an embodiment will be described with reference to the accompanying drawings. In this specification and drawings, substantially identical components are designated by the same reference numerals, and redundant explanations may be omitted.

[0039] [Building according to the embodiment and its construction method] An example of a building and a construction method thereof according to the embodiment will be described with reference to Fig. 2 to Fig. 6. Fig. 2 is a vertical cross-sectional view showing an example of a building according to the embodiment. Fig. 4 and Fig. 5 are views explaining step A of an example of a construction method for a building according to the embodiment, and Fig. 6 is a view explaining steps A and B of an example of a construction method for a building according to the embodiment, following Fig. 5. Fig. 2 is also a view explaining step C of an example of a construction method for a building according to the embodiment.

[0040] The ground G in the construction area shown in the figure consists of, from top to bottom, a sand layer GA, a hard sand layer GB, and a clay layer GC (an example of a low-permeability layer, which includes impermeable layers), and the groundwater level is relatively high.

[0041] The building 200 is constructed by joining the side walls 15 and foundation beams 17 (both of which are examples of constituent members) of the basement 11 of the building 10 located in the sand layer GA to a soil cement diaphragm column wall 20 constructed around the periphery of the building 10. For example, a soil cement diaphragm column wall 20 having a rectangular frame shape in plan view is constructed around the side walls 15 of the basement 11 of the building 10, which is rectangular in plan view, and the two are joined at multiple locations. Note that the shape of the building 10 in plan view is diverse, and the soil cement diaphragm column wall 20 is constructed in a frame shape that corresponds to the shape of the building 10 in plan view.

[0042] The building 10 may be made of RC (Reinforced Concrete), S (Steel), SRC (Steel Reinforced Concrete), or a hybrid of these structures, and includes a variety of forms such as office buildings, apartment buildings, gymnasiums, shopping malls, and various public buildings. In the illustrated example below, the building will be described as having at least the side walls 15 and foundation beams 17 of the basement 11 made of RC.

[0043] On the other hand, the soil cement continuous column wall 20 is constructed by overlapping portions of the soil cement 30, which is circular in plan view, with a core material 40 made of H-shaped steel embedded inside the soil cement 30 in the circular drilled hole G1 in plan view. Here, in addition to H-shaped steel, steel sheet piles, secondary concrete products, etc. may also be used as the core material.

[0044] The soil cement 30 is produced by mixing and stirring the earth and sand generated by excavating the ground G with cement milk discharged from the tip of a multi-shaft mixing auger or the like (not shown), and is constructed by inserting a core material 40 into the soil cement before it hardens.

[0045] The bottom end 35 of the soil cement 30 is embedded in the clay layer GC, which is a low-permeability layer, thereby preventing groundwater from leaking toward the building 10 when the building 10 is constructed (see the leaking in the X1 direction in Figure 1).

[0046] Furthermore, the lower end 45 of the core material 40 is positioned above the lower end 35 of the soil cement 30 by a distance t1, and with this configuration, the compressive force N1 acting on the core material 40 from the building 10 is transmitted to the soil cement 30 via the lower end 45 of the core material 40, and then to the ground G (here, clay layer GC) via the lower end 35 of the soil cement 30, so that the area of ​​the lower end of the soil cement 30 is taken into account when calculating the tip bearing capacity P1. Here, the distance t1 can be set to about 1.5 to 2 times the height of the web 41 of the core material 40.

[0047] However, since the lower end 35 of the soil cement 30 is embedded in the soft clay layer GC, while it is possible to prevent groundwater from seeping in as described above, it becomes difficult to estimate the large tip bearing capacity P1 of the soil cement 30.

[0048] Therefore, the soil cement 30 in the illustrated example has an expanded base 30A that is triangular in side view in the area of ​​the hard sand layer GB, and a large bearing capacity P2 is expected by having the lower end 36 of the expanded base 30A located in the hard sand layer GB. Here, the shape of the expanded base in side view may be a curved spindle shape or the like, in addition to the triangular shape shown in the illustration.

[0049] At a position corresponding to the expanded bottom portion 30A in the core material 40, one ends of two shaft members 63, 64 are rotatably assembled to each other via a first pivoting portion 61, and the other ends of the two shaft members 63, 64 are rotatably attached via two second pivoting portions 62A, 62B located at different upper and lower positions on the flanges 42, 43 of the core material 40.

[0050] A plurality of guides 65 are attached at intervals to the flanges 42, 43 of the core material 40, and a wire 66 (an example of a wire) hanging down from the ground is inserted through each guide 65, and its lower end is attached to the first rotating portion 61.

[0051] Then, by pulling up the wires 66 in the Y2 direction from the ground, the two shaft members 63, 64 are deployed laterally, and a part of them enters the inside of the expanded bottom portion 30A as shown in FIG.

[0052] In this way, by having portions of the two shaft members 63, 64 enter the inside of the expanded bottom portion 30A, the pushing force N1 acting on the core material 40 can be effectively transmitted to the expanded bottom portion 30A via the two shaft members 63, 64.

[0053] Furthermore, part of the shear force S acting on the expanded bottom portion 30A is borne by the two shaft members 63, 64, and the shear force borne by the soil cement 30 in the expanded bottom portion 30A can be reduced.

[0054] Here, a longitudinal cross-sectional view of another example of the expanded bottom portion is shown in Figure 3. In the illustrated example, instead of two rotatable shaft members 63, 64 relative to each other, multiple stud dowels 70 (an example of linear protrusions) extending in the direction of the expanded bottom portion 30A are attached by welding to each of the flanges 42, 43.

[0055] The multiple stud dowels 70 in the illustrated example also allow the pushing force N1 acting on the core material 40 to be effectively transmitted to the expanded bottom portion 30A via each stud dowel 70. Furthermore, by having the multiple stud dowels 70 bear part of the acting shear force S, the shear force borne by the soil cement 30 in the expanded bottom portion 30A can be reduced.

[0056] According to the soil cement column-type continuous wall 20 shown in the figure, the pushing force N1 acting from the building 10 on the core material 40 is supported by the supporting force (total supporting force) consisting of the tip supporting force P1 of the soil cement 30, the supporting force P2 of the lower end 36 of the expanded base portion 30A, and the peripheral friction force F between the soil cement 30 and the surrounding ground G, and the pushing force N1 can be transmitted to the ground G.

[0057] As shown in Figure 1, if there is a hard sand layer GB or the like above the impermeable layer GC, a large bearing capacity P2 can be obtained by providing an expanded bottom portion 30A in the hard sand layer GB. However, even if there is no hard sand layer GB and the ground consists only of a soft clay layer GC, the bearing capacity of the soil cement 30 can be increased by providing the expanded bottom portion 30A in the soil cement 30.

[0058] Here, in ground consisting only of a soft clay layer GC, for example, by providing multiple stages of expanded bottom sections 30A at a midpoint in the longitudinal direction of the soil cement 30, a bearing capacity P2 can be obtained from the multiple expanded bottom sections 30A, and therefore, soil cement 30 with the desired bearing capacity can be formed even in soft ground.

[0059] Furthermore, if there is a hard sand layer GB as in the illustrated example and the thickness of the hard sand layer GB is large, by providing multiple stages of expanded bottom sections 30A at intervals above and below within the hard sand layer GB, an even greater bearing capacity of the lower end 35 of the expanded bottom section 30A can be obtained, and the total bearing capacity of the soil cement 30 can be further increased.

[0060] The soil cement column-type continuous wall 20 shown in the figure not only serves as a retaining wall when constructing the building 10, but also functions as the foundation of the building 10 after it is constructed by being joined to the underground section 11 of the building 10.

[0061] Next, an example of a construction method for a building according to the embodiment will be described with reference to FIGS. 4 to 6 and FIG. 2 in this order.

[0062] In the construction method for a building, first, prior to the construction of the building, soil cement 30 is constructed around the construction area of ​​the building as a retaining wall, for example, constituting a soil cement column-type continuous wall 20 having a rectangular frame shape in plan view.

[0063] The construction of the soil cement 30 can be carried out using the well-known SMW (Soil Mixing Wall) method, which begins with the removal of underground obstacles, followed by the installation of a guide wall (not shown), the mixing of the soil cement, and the drilling of the designed cement slurry while discharging it from the tip of the auger head of a multi-shaft auger or similar machine. After reaching the specified depth, the auger head is raised while repeatedly mixing, thereby creating the soil cement 30 in the drilled hole G1. At this time, the bottom end 35 of the soil cement 30 is embedded in the impermeable layer GC.

[0064] Furthermore, in order to construct the expanded bottom portion 30A at a position corresponding to the hard sand layer GB, the soil cement 30 in the illustrated example uses an auger head that can be rotated freely around a rotation axis, and the expanded bottom portion 30A is constructed by rotating the auger head sideways from the inside of the cylindrical soil cement 30 and drilling and mixing the cement slurry while ejecting it from the tip of the auger head.

[0065] Next, as shown in Figure 5, before the soil cement 30 hardens, the core material 40 is inserted into the soil cement 30 in the Y1 direction and erected. The wall construction procedure can be a continuous method in which a first element is constructed, then a second element is constructed at a distance, and then the holes at both ends of the third element are overlapped with the holes at one end of both the first and second elements, or a combined method of pre-drilling, in which multiple holes are pre-drilled at intervals in positions where the holes of each element will follow, and then each element is constructed so that the holes of each element overlap the holes drilled pre-drilled.

[0066] When this core material 40 is erected, two rotatable shaft members 63, 64 are attached to the middle of the core material 40, and a wire 66, one end of which is attached to a first rotating portion 61 at the end of the shaft members 63, 64, extends to the upper end of the core material 40 while being guided by a plurality of guides 65 attached at intervals to the core material 40.

[0067] When the core material 40 is erected, the two shaft members 63, 64 do not extend out to the side but hang down as shown in Figure 5, and therefore the two shaft members 63, 64 do not become an obstacle when the core material 40 is erected.

[0068] As shown in Figure 6, after the lower end 45 of the core material 40 is erected to a predetermined position (a position spaced upward by a distance t1 from the lower end 35 of the soil cement 30), the wire 66 is pulled upward in the Y2 direction, causing the two shaft members 63, 64 to be lifted in the Y3 direction to the side of the soil cement 30 and unfold, and some of them enter the inside of the expanded bottom portion 30A, thereby erecting the core material 40 and forming the unfolded posture of each shaft member 63, 64 (this is process A).

[0069] Next, as shown in Figure 6, the ground G on the building side of the soil cement column-type continuous wall 20 is excavated in the Y5 direction up to the flooring surface G2, and the upper region 31 of the soil cement column-type continuous wall 20 is cut to expose a portion of the first flange 42.

[0070] Next, a plurality of shear connectors 50 are welded to the exposed first flange 42 (this completes step B).

[0071] Next, as shown in Figure 2, the side walls 15 and foundation beams 17 of the underground portion 11 of the building 10 that abut at least the first flange 42 are constructed, and multiple shear connectors 50 are embedded in the side walls 15 and foundation beams 17 to interconnect the side walls 15 and foundation beams 17 of the underground portion 11 and the soil cement column-type continuous wall 20.

[0072] Thereafter, the entire building 10 is constructed, whereby the building 200 in which the building 10 and the soil cement diaphragm wall 20 are joined together is constructed (this is the end of step C).

[0073] According to the construction method shown in the figure, it is possible to construct a building 200 that is integrally equipped with a soil cement column-type continuous wall 20 that is equipped with soil cement 30 that has high bearing capacity while preventing groundwater from leaking in.

[0074] The present invention is not limited to the configurations shown here, and other embodiments may be possible in which other components are combined with the configurations described in the above embodiments. In this regard, the present invention can be modified within the scope of the present invention, and can be appropriately determined depending on the application form. [Explanation of symbols]

[0075] 10: Building 11: Underground 15: Side wall (component) 16: Pillar (component) 17: Foundation beam (component) 20: Soil cement diaphragm wall 30: Soil cement 30A: Enlarged bottom 31: Upper area 35: Bottom (bottom of soil cement) 36: Bottom end (bottom end of the flared part) 40: Core material (H-beam) 41:Web 41a: Wide surface 42: First flange 43: Second flange 45: Bottom edge 50: Shear connector 61: First rotating part 62A, 62B: Second rotating part 63,64: Shaft member 65: Guide 66: Wire rod 70: Stud dowel (straight protrusion) 200: Buildings G: Ground GA: Sand layer GB: hard sand layer GC: Clay layer (impermeable layer) G1: Drilling G2: Floor mounting surface N1: Pushing force S: Shear force P1:Tip bearing capacity P2: Bearing capacity (bearing capacity at the bottom of the expanded base) F: Surface friction

Claims

1. A building in which constituent members of an underground portion of a building located in the ground are joined to a soil cement continuous column wall provided around the building, and the soil cement continuous column wall has a steel core material buried inside the soil cement, A building characterized in that the soil cement has its lower end embedded in a low-permeability layer and has an expanded bottom portion that extends laterally above the lower end.

2. The building described in claim 1, characterized in that the side view shape of the expanded bottom portion is such that the lower end of the expanded bottom portion extending laterally from the soil cement is the longest, the upper end of the expanded bottom portion is on the side of the soil cement, and the line connecting the lower end and the upper end is either a straight line, a curved line, or a combination of a straight line and a curved line.

3. 3. The building according to claim 2, wherein the expanded bottom portion is provided in a sand layer or hard sand layer shallower than the impermeable layer.

4. 4. A building according to claim 1, wherein a linear protrusion extending in the direction of the expanded bottom portion is provided at a position on the core material corresponding to the expanded bottom portion.

5. 5. The building of claim 4, wherein the protrusions are stud dowels.

6. One ends of two shaft members are rotatably assembled to each other via a first rotating part at a position corresponding to the expanded bottom portion of the core material, and the other ends of the two shaft members are rotatably attached to the core material via two second rotating parts located at different vertical positions, A building described in any one of claims 1 to 3, characterized in that by pulling up the wire attached to the first pivoting part from the ground, the two axial members expand sideways and parts of them enter the inside of the expanded base part.

7. A building described in any one of claims 1 to 3, characterized in that the lower end of the core material is located above the lower end of the soil cement, and a predetermined distance is set between the two lower ends.

8. A construction method for a building in which components of an underground portion of a building located in the ground are joined to a soil cement diaphragm wall provided around the building, Step A is to construct a soil cement column-type continuous wall by erecting a core member formed of an H-shaped steel beam having a first flange on the building side, a second flange on the opposite side of the building, and a web inside the soil cement in the drilled hole; Step B: cutting the soil cement at the upper end of the soil cement diaphragm wall to expose a portion of the first flange, and joining a stud dowel to the exposed portion of the first flange; and a step C of constructing the structural member of the building that abuts against the first flange and embedding the stud dowel in the structural member, thereby joining the structural member of the underground portion and the soil cement columnar continuous wall to each other, In the step A, The tip of the soil cement is embedded in the impermeable layer, A construction method for a building, characterized in that a flared bottom portion that extends laterally is constructed above the tip of the soil cement.

9. 9. A method for constructing a building according to claim 8, characterized in that the expanded bottom portion is constructed at a position corresponding to a sand layer or hard sand layer shallower than the impermeable layer.

Images