Core material for earth retaining wall, earth retaining wall including the same, and composite wall

Abstract

To provide a core material for an earth retaining wall, which does not have a headed stud at a front end, the earth retaining wall equipped with the core material, and a composite wall.SOLUTION: A core material 100 for an earth retaining wall 200 constructs a composite wall 300 serving as an underground outer wall of a building skeleton 400 by being integrated with a concrete wall 330. The core element 100 comprises an H-beam 20 and a plurality of shear connectors 10 welded to the web 22 of the H-beam 20 at the leading end 26 of the core element 100. The shear connector 10 is a shape steel or a square pipe having an axial core 16 extending perpendicularly to the longitudinal direction of the H-shaped steel 20.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a core material for an earth retaining wall, an earth retaining wall provided with the same, and a composite wall. [Background technology]

[0002] An "earth retaining wall" is a structure built to prevent the collapse of the surrounding ground during excavation; a well-known example is a soil cement wall. Soil cement refers to a mixture of earth and sand and cement milk. A soil cement wall is formed by inserting core material for the earth retaining wall (e.g., H-shaped steel) into soil cement, which is created by mixing and stirring in-situ soil and cement milk; known examples include soil cement diaphragm walls and soil cement column walls. A technique for manufacturing a composite wall by integrating the upper part of an earth retaining wall with the reinforced concrete wall of the building frame has been known for some time. The core material used in the soil cement wall of the earth retaining wall is used as a vertical load transfer mechanism for the building frame. Such earth retaining walls are disclosed, for example, in Patent Document 1 and Patent Document 2. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6869198 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-209547 Summary of the Invention [Problem to be solved by the invention]

[0004] Fig. 1 is an enlarged view of a tip portion 526 of a core material 500 for an earth retaining wall disclosed in Patent Document 2. Fig. 1(A) is a front view, and Fig. 1(B) is a view taken along the arrow AA in Fig. 1(A). Conventionally, a headed stud 510 has been attached to the tip 526 of the H-shaped steel 520 that serves as the core material 500 for the retaining wall as a shear connector to better transmit the vertical load from the core material 500 for the retaining wall to the soil cement and the ground.

[0005] The process of welding the headed studs 510 to the H-shaped steel 520 of the core material 500 for the retaining wall is carried out in a factory. At that time, headed studs 510 were not widely available on the market and could not be obtained through the same channels as general steel materials. Therefore, when manufacturing the core material 500 in a factory, the headed studs 510 had to be purchased from a different channel than the other steel materials, which made the preparation of the core material 500 complicated.

[0006] Furthermore, the headed stud 510 can only be welded by a specially qualified welder (hereinafter referred to as a stud welding technician) who has passed the "Stud Welding Technology Certification Examination" of the Stud Association of Japan. Furthermore, performing "horizontal welding" of the headed stud 510 requires an even higher level of expertise among stud welding technicians.

[0007] Therefore, a welding technician who only has the general welding qualification "Qualification for a technician engaged in welding work in the production of steel structures" (hereinafter referred to as a general welding technician) cannot weld the headed stud 510 to the core material 500, so it is necessary to ask a stud welding technician to perform only the headed stud welding process, which is troublesome. Therefore, there was a need to develop a core material for earth retaining walls that could be manufactured without welding headed studs to the tip of the core material.

[0008] The present invention has been devised to solve the above-mentioned problems, and an object of the present invention is to provide a core member for an earth retaining wall that does not have a headed stud at its tip, and an earth retaining wall and a composite wall that include the same. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems and achieve the object, the core material of the present invention is a core material for an earth retaining wall, The core material is an H-shaped steel, A plurality of shear connectors welded to the web of the H-shaped steel at the tip of the core material, The shear connector is a structural steel or square pipe whose axis extends perpendicular to the longitudinal direction of the H-shaped steel.

[0010] According to the present invention, a soil cement formed by mixing and stirring soil and cement and having a lower end located within a support layer is provided. and the core material as described above, which is inserted into the soil cement until the tip is facing downward and positioned within the supporting layer.

[0011] Further, according to the present invention, there is provided a composite wall that serves as an underground exterior wall of a building skeleton, The above-mentioned retaining wall, a plurality of headed studs each having one end fixed to a flange of the H-shaped steel exposed from the soil cement on the upper side of the retaining wall; and a concrete wall constructed to be integrated into the retaining wall by connecting rebar to the headed studs. [Effects of the Invention]

[0012] According to the present invention, the shear connector welded to the tip of the core material is a general steel material such as a section steel or a square pipe. Therefore, the welding process of the shear connector 10 to the H-section steel can be performed by only a general welding technician.

[0013] Furthermore, because the shear connectors of the present invention are made of structural steel or square pipes, they can be obtained from the same general steel sources as H-beams. Furthermore, because structural steel and square pipes are both general steel materials, they are widely distributed in the market and are easy to obtain. Therefore, the core material of the present invention can improve convenience when preparing materials for the core material. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an enlarged view of the tip of a core material for an earth retaining wall disclosed in Patent Document 2. [Figure 2] 1 is a vertical cross-sectional view of a first embodiment of a composite wall according to the present invention; [Figure 3] (A) is a cross-sectional view taken along line BB in FIG. 2, and (B) is a cross-sectional view taken along line CC in FIG. 3(A). [Figure 4] FIG. 2 is a perspective view of the tip of the core material of the first embodiment. [Figure 5] 3A and 3B are a front view and an arrow view of the tip portion of the core material of the first embodiment. [Figure 6] FIG. 10 is a front view of the tip of the core material of the first embodiment, showing another form of the shear connector of the first example. [Figure 7] FIG. 10 is a perspective view of the tip of the core of the first embodiment having the shear connector of the second example. [Figure 8] FIG. 10 is a front view of the tip of the core of the first embodiment having a shear connector of the second example. [Figure 9] FIG. 10 is a front view of the tip of the core of the first embodiment having a shear connector of the third example. [Figure 10] FIG. 10 is a perspective view of the tip of a core material according to a second embodiment. [Figure 11] 10A and 10B are a front view and an arrow view of a tip portion of a core material of a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, common parts in the drawings are given the same reference numerals, and duplicated explanations will be omitted.

[0016] (First embodiment) The earth retaining wall 200 of this embodiment is an earth retaining wall that is integrated with a concrete wall 330 to construct a composite wall 300 that becomes the underground exterior wall of a building skeleton 400. Note that the earth retaining wall 200 of this embodiment does not assume that the core material 100 will be used as the pile foundation 410 of the foundation structure of a building.

[0017] FIG. 2 is a vertical cross-sectional view of a first embodiment of a composite wall 300 according to the present invention. In this figure, a composite wall 300 has a retaining wall 200 in part. Hereinafter, the left side of the retaining wall 200 in this figure will be referred to as the "outside" or "underground side," and the right side will be referred to as the "inside" or "building side."

[0018] 3A is a cross-sectional view taken along line BB in FIG. 2, and FIG. 3B is a cross-sectional view taken along line CC in FIG. 3A. 2 and 3, the retaining wall 200 of this embodiment is a soil cement wall in which a plurality of soil cement pillars 211 are continuously integrated and constructed underground 1. The retaining wall 200 has soil cement 210 and core materials 100 inserted into the soil cement 210 at appropriate intervals.

[0019] The earth retaining wall 200 is constructed by an improved earth retaining method with core material, such as the SMW method. The "improved earth retaining method with core material" is a construction method in which a composite wall 300 is constructed using a core material 100. For example, in the SMW method, cement milk is mixed and stirred with the in-situ soil in the drilled hole 220, and the columns are gradually overlapped to construct a continuous pile retaining wall. The mixture created by mixing and stirring the in-situ soil and cement milk in the SMW method is called a ground improvement body (hereinafter referred to as soil cement 210).

[0020] As shown in FIG. 3(B), the holes 220 in the soil cement 210 may alternate between multiple deep holes 220a drilled to a depth such that their lower ends reach the support layer 1a and multiple shallow holes 220b whose lower ends are located above the support layer 1a. The support layer 1 may be, for example, hard ground. Such soil cement 210 is formed integrally by the pillars in the deep holes 220a and shallow holes 220b slightly overlapping each other. Alternatively, all of the holes 220 in the soil cement 210 may be deep holes 220a. As a result, the lower end 210a of the soil cement 210 is located within the bearing layer 1a, and the portion of the retaining wall 200 provided in the deep hole 220a can function as a bearing force transmission portion 230 that transmits vertical loads to the bearing layer 1a.

[0021] When the earth retaining wall 200 is used as part of the underground exterior wall of the building skeleton 400, the soil cement strength of the earth retaining wall 200 of this embodiment is 2 N / mm 2 It is preferable that:

[0022] The core material 100 of the first embodiment is a core material for the earth retaining wall of this embodiment. Multiple core materials 100 are embedded inside the earth retaining wall 200. The core materials 100 extend vertically (up and down in FIGS. 2 and 3(B)) at intervals from one another in the horizontal direction (the direction perpendicular to the paper surface of FIG. 2, the left and right direction in FIG. 3(A)).

[0023] The core material 100 of this embodiment is a structural steel 20 to which a plurality of shear connectors 10 are welded, and is preferably an H-shaped steel to which shear connectors 10 are welded. The plurality of core materials 100 may be provided in a plurality of soil cement columns 211, or one or more soil cement columns 211 without structural steel 20 may be provided between adjacent core materials 100. Hereinafter, this embodiment will be described using an example in which the structural steel 20 is an H-shaped steel.

[0024] Multiple shear connectors 10 are welded to both sides of the web 22 of the H-shaped steel 20 at the tip 26, which is one longitudinal end of the core material 100. The shear connectors 10 are structural steel or square pipes whose axis 16 extends perpendicular to the longitudinal direction of the H-shaped steel 20. The manufacturing process of the core material 100, in which the shear connectors 10 are welded to the H-shaped steel 20, is carried out in a factory. The completed core material 100 is carried to the construction site and inserted into soil cement 210 with the tip 26, to which the shear connector 10 is welded, facing downward, as shown in Figure 2. At this time, the core material 100 is adjusted so that it extends vertically and one side of the flange 24 of the H-shaped steel faces the building.

[0025] The size of the soil cement pillars 211 and the spacing between the core materials 100 are set according to the soil pressure and other factors of the target underground 1. For example, for the soil cement 210 in the deep hole 220a, an H-shaped steel 20 of a length that allows its lower end to be embedded in the support layer 1a is used as the core material 100. The core material 100 is inserted into the soil cement 210 until its tip 26 is positioned within the support layer 1a. With this configuration, the core material 100 of the deep hole 220a of the earth retaining wall 200 can transmit the vertical load acting on the earth retaining wall 200 to the soil cement 210 in the deep hole 220a and the supporting layer 1a.

[0026] The composite wall 300 comprises a retaining wall 200 , a plurality of headed studs 320 , and a concrete wall 330 . When constructing the composite wall 300, after the soil cement 210 has hardened, the soil cement 210 is scraped away from the portion (upper portion) inside the retaining wall 200 that will become the composite wall 300, exposing the inner flange 24 of the H-shaped steel 20. Next, one end of a plurality of headed studs 320 is fixed to the exposed flange 24 by welding or screwing. At this time, the headed studs 320 are fixed so that their axes extend perpendicular to the surface of the flange 24.

[0027] Reinforcing bars (not shown) are connected to the headed studs 320, so that the concrete wall 330 is constructed to be integrated with the retaining wall 200. The composite wall 300 constructed in this way becomes the underground exterior wall of the building skeleton 400. With this configuration, the core material 100 of this embodiment bears the vertical load of the building skeleton 400 as part of the underground exterior wall of the building skeleton 400. In other words, the composite wall 300 of the present invention thus makes the core material 100 of the temporary earth retaining wall 200 bear the bearing force.

[0028] Fig. 4 is a perspective view of the tip portion 26 of the core material 100 of the first embodiment. Fig. 4 shows a perspective view of part D in Fig. 2. Fig. 5 also shows (A) a front view of the tip portion 26 of the core material 100 of the first embodiment, and (B) a view taken along the arrow EE in Fig. 5(A). The core material 100 of the first embodiment is characterized in that the shear connector 10 is welded to the web 22 of the H-shaped steel 20 so that the axis 16 of the shear connector 10 extends perpendicular to both the longitudinal direction of the H-shaped steel 20 and the surface 22a of the web 22. In other words, the shear connector 10 of the core material 100 of the first embodiment is characterized in that one longitudinal end face 11 thereof is welded to the surface 22a of the web 22 in close face-to-face contact.

[0029] The shear connector 10 is, for example, a general steel section or square pipe. "General steel" refers to general structural rolled steel (steel specified in "JIS G 3101" or "JIS G 3192"). As shown in FIG. 5(B), the longitudinal length of the shear connector 10 is preferably such that when one longitudinal end face 11 is welded to the surface 22a of the web 22, the other longitudinal end 12 of the shear connector 10 is located closer to the web than the flange 24 of the H-shaped steel 20. This prevents the H-shaped steel 20 from being hindered during transportation. Furthermore, when welding the shear connectors 10 to both sides of the web 22, it is preferable to position the shear connectors 10 so that the welding position on the front side of the web 22 does not overlap with the welding position on the back side. This prevents the welding from affecting the web 22 due to overlapping welds on the front and back sides.

[0030] (First Example of Shear Connector 10 in First Embodiment) 2, 4, and 5 illustrate a core 100 having a shear connector 10 of the first embodiment. Also, FIG. 6 is a front view of the tip 26 of the core 100 of the first embodiment, showing another form of the shear connector 10 of the first embodiment. The shear connector 10 of this embodiment is a general steel material having multiple flat plate portions 14 that are perpendicular to each other, and may be, for example, an L-shaped steel (Figures 5 and 6(A)), an H-shaped steel (Figure 6(B)), a channel steel (Figure 6(C)), or a square pipe (Figure 6(D)).

[0031] As mentioned above, headed studs have traditionally been used as shear connectors at the bottom end of the core material of retaining walls. Headed studs are commercially available with shaft diameters up to 25 mm, but the shaft diameter of headed studs that can be used for horizontal welding is limited to 16 mm or less by the Japan Stud Association. The bearing strength of a headed stud when used as a shear connector is affected by the shank area of ​​the headed stud. The maximum shank diameter of a headed stud that can be welded horizontally to the bottom end of an H-section steel is small at 16 mm, and the shank area is also small accordingly, so only a small bearing strength can be obtained from a single headed stud. Therefore, in order to obtain the bearing strength required for the core material, it was necessary to weld many headed studs to the H-section steel, as shown in Figure 1.

[0032] On the other hand, when a general steel material welded so that the shaft center 16 extends perpendicular to the surface 22a of the web 22 is used as the shear connector 10, the strength of the general steel material may be dependent on the cross-sectional area of ​​the plate thickness when cut by a plane perpendicular to the shaft center 16. For example, the smallest standard cross-sectional dimensions of commercially available L-shaped steel are 40mm x 40mm, and this cross-sectional area is larger than the axial area of ​​a headed stud with a shaft diameter of 16mm. Similarly, the smallest standard cross-sectional dimensions of commercially available H-shaped steel are 100mm x 50mm, channel steel 75mm x 40mm, and square pipe 60mm x 30mm, and all of these cross-sectional areas are larger than the axial area of ​​a headed stud with a shaft diameter of 16mm.

[0033] As such, the cross-sectional area of ​​common steel materials available on the market is larger than the axial area of ​​headed studs that can be welded horizontally. In other words, using steel sections or square pipes as shear connectors 10 for the core material 100 is more likely to provide a greater bearing strength per shear connector 10 than using headed studs. Furthermore, since the general steel material has a shape in which multiple flat plate portions 14 intersect at right angles, it is less likely to bend than a rod-shaped headed stud.

[0034] Furthermore, since the tip 26 of the core material 100 is unlikely to be subjected to horizontal forces that would cause the soil cement 210 to peel off from the H-shaped steel 20, the shear connector 10 attached to the tip 26 of the core material 100 does not need a protrusion, such as the head of a headed stud, to hook onto the soil cement 210.

[0035] Therefore, the core material 100 of this embodiment can reduce the number of shear connectors 10 required to provide the bearing strength required for the tip portion 26 of the core material 100 compared to conventional core materials. As a result, the core material 100 of this embodiment can reduce the number of shear connectors 10 to be welded to the H-shaped steel 20, and therefore the material costs and construction labor can be reduced compared to conventional core materials. Furthermore, the core material 100 of this embodiment can shorten the manufacturing period of the core material 100 compared to conventional core materials, which in turn shortens the construction period of the earth retaining wall 200 compared to conventional core materials, and ultimately reduces the construction costs of the earth retaining wall 200 compared to conventional core materials.

[0036] Furthermore, since the shear connector 10 of this embodiment is made of general steel, the welding process of the shear connector 10 to the H-beam 20 can be carried out by only a person with general welding skills. Furthermore, since the shear connector 10 of this embodiment is made of general steel, the shear connector 10 can be obtained from the same general steel procurement channels as the H-shaped steel 20, thereby improving convenience when preparing the material for the core material 100.

[0037] The shear connector 10 of the first embodiment is characterized in that the axis 16 extends perpendicular to the surface 22a of the web 22, and at least one of the flat portions 14 is welded to the H-shaped steel 20 so that it is perpendicular to the longitudinal direction of the H-shaped steel 20 and perpendicular to the surface 22a of the web 22. Because the shear connector 10 of the first embodiment is welded in this orientation, when the core material 100 is embedded in the soil cement 210 so that it extends vertically, at least one of the flat portions 14 of the shear connector 10 extends horizontally. This allows the core material 100 to efficiently transmit the vertical load of the building skeleton 400 to the soil cement 210 and the supporting layer 1a. Furthermore, this configuration allows the core material 100 to strongly resist any upward tension that may be applied.

[0038] (Second Example of Shear Connector 10 in First Embodiment) FIG. 7 is a perspective view of the distal end 26 of the core 100 of the first embodiment having the shear connector 10 of the second embodiment. FIG. 8 is a front view of the tip portion 26 of the core 100 of the first embodiment having the shear connector 10 of the second embodiment.

[0039] The shear connector 10 of the second embodiment is an L-shaped steel 10 having two flat plate portions 14 that are perpendicular to each other, and is characterized in that the axis 16 extends perpendicular to the surface 22a of the web 22 and the corner 13 is welded downward. In the second embodiment of the shear connector 10, the corners 13 of the L-shaped steel 10 face downward, which reduces the resistance to inserting the core material 100 into the soil cement 210, thereby preventing the core material 100 from remaining high.

[0040] The shear connectors 10 may be horizontally offset from one another on the web 22. For example, the horizontally offset shear connectors 10 may be at the same height as shown in Figure 7(A), or may be offset in height as shown in Figure 7(B). By offsetting the height of the horizontally offset shear connectors 10 as shown in Figure 7(B), the distance between the shear connectors 10 increases, further reducing the resistance when inserting them into the soil cement 210. Furthermore, the shear connector 10 of the second embodiment has a configuration in which the two flat plate portions 14 are spread out upward, so that air can be prevented from accumulating below the shear connector 10. Other configurations and effects of the shear connector 10 of the second embodiment are similar to those of the shear connector 10 of the first embodiment.

[0041] (Third Example of Shear Connector 10 in First Embodiment) FIG. 9 is a front view of the distal end 26 of the core 100 of the first embodiment having the shear connector 10 of the third embodiment. Like the shear connector 10 of the second embodiment, the shear connector 10 of the third embodiment is an L-shaped steel 10 having two flat plate portions 14 that are perpendicular to each other, and is welded so that the axis 16 of the shear connector 10 extends perpendicular to the surface 22a of the web 22.

[0042] The shear connector 10 of the third embodiment is characterized in that the corners 13 are welded in the horizontal direction. For example, the shear connectors 10 of the third embodiment may be arranged in multiple rows spaced apart in the vertical direction, as shown in Figure 9. Furthermore, it is preferable that the shear connectors 10 of the third embodiment, which are arranged in multiple rows, are arranged symmetrically in the left and right directions in this figure so that unnecessary force in the horizontal direction (for example, the left and right direction in Figure 9) is not generated at the tip end 26 of the core material 100 when an upward pulling force is applied to the core material 100. For example, as shown in Figure 9(A), the left and right rows of shear connectors 10 of the third embodiment may be welded with their corners 13 facing the center in the left and right direction, or as shown in Figure 9(B), they may be welded with their corners 13 facing the flanges 24 of the H-shaped steel 20.

[0043] Furthermore, in the shear connector 10 of the third embodiment, the flat plate portion 14 extending upward from the corner 13 is inclined relative to the horizontal plane, so that air pockets can be prevented from forming below the flat plate portion 14 . Furthermore, in the third embodiment, when inserting the core material 100 into the soil cement 210, the shear connector 10 inserts the core material 100 into the soil cement 210 from the end of the flat plate portion 14, thereby reducing the resistance when inserting the core material 100 and preventing the core material 100 from remaining high. The rest of the configuration and effects of the shear connector 10 of the third embodiment are similar to those of the shear connector 10 of the first or second embodiment.

[0044] (Second embodiment) Fig. 10 is a perspective view of the tip portion 26 of the core material 100 of the second embodiment. Fig. 11(A) is a front view of the tip portion 26 of the core material 100 of the second embodiment, and Fig. 11(B) is a view taken along the arrow FF in Fig. 11(A). The core material 100 of the second embodiment has a plurality of flat plate portions 14 in which the shear connectors 10 are perpendicular to one another. The core material 100 of the second embodiment is characterized in that the outer surface 14a of one of the plurality of flat plate portions 14 of each shear connector 10 is in close contact with the surface 22a of the web 22, and at least one of the other flat plate portions 14 is welded so as to extend perpendicular to the surface 22a of the web 22.

[0045] This configuration of the core material 100 of the second embodiment allows one of the large flat surfaces of the shear connector 10 to be welded firmly face-to-face to the surface 22a of the web 22, allowing the shear connector 10 to resist strong forces.

[0046] Furthermore, since the shear connector 10 of the second embodiment has a flat plate portion 14 extending vertically to the surface 22a of the web 22, when the core material 100 is embedded in the soil cement 210 so as to extend vertically, the flat plate portion 14 extends horizontally. This allows the core material 100 to efficiently transmit the vertical load of the building skeleton 400 to the soil cement 210 and the supporting layer 1a. Furthermore, with this configuration, when upward tension is applied to the core material 100, the flat plate portion 14, which is perpendicular to the tension, is fixed to the tip portion 26 of the core material 100, so that it can strongly resist the tension. Note that the flat plate portion 14, which extends perpendicular to the surface 22a of the web 22, may be slightly tilted relative to the horizontal direction to prevent air pockets from forming under the flat plate portion 14, which extends horizontally during use.

[0047] The shear connector 10 in the core material 100 of the second embodiment may be any ordinary steel material having multiple flat plate portions 14 that are perpendicular to one another. The shear connector 10 of the second embodiment may be, for example, an L-shaped steel, an H-shaped steel, a channel steel, or a square pipe. When the shear connector 10 of the second embodiment is welded to the surface 22a of the web 22, it is preferable that the flat plate portion 14 of the shear connector 10 is located closer to the web than the flange 24 of the H-shaped steel 20. This prevents the H-shaped steel 20 from being hindered during transportation. The rest of the configurations and effects of the core material 100, the retaining wall 200, and the composite wall 300 of the second embodiment are the same as those of the first embodiment.

[0048] According to the present invention described above, the shear connector 10 welded to the tip 26 of the core material 100 is a general steel material such as a structural steel or a square pipe. Therefore, the welding process of the shear connector 10 to the H-shaped steel 20 can be performed by only a general welding technician.

[0049] Furthermore, since the shear connector 10 of the present invention is made of general steel, the shear connector 10 can be obtained from the same general steel procurement route as the H-beam 20. Furthermore, since both the structural steel and the square pipe are general steel, they are widely distributed in the market and are easy to obtain. Therefore, the core material 100 of the present invention can improve the convenience when preparing the material for the core material 100.

[0050] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. [Explanation of symbols]

[0051] 1 underground, 1a support layer, 100 core material, 10 Shear connector (L-shaped steel), 11 one end surface in the longitudinal direction, 12 the other end surface in the longitudinal direction, 13 corners, 14 flat plate part, 14a outer surface, 16 axis center, 20 section steel (H section steel), 22 web, 22a web surface, 24 flange, 26 tip, 200 retaining walls, 210 soil cement, 210a bottom end of soil cement; 211 soil cement pillars, 220 holes, 220a deep holes, 220b shallow holes, 230 bearing force transmission part, 300 composite wall, 320 headed stud, 330 concrete wall, 400 Building frame, 410 Pile foundation, 500 prior art core material, 510 headed studs, 520 H-beam, 522 Web, 524 flange, 526 tip

Claims

1. A core material for an earth retaining wall, The core material is an H-shaped steel, a plurality of shear connectors welded to the web of the H-shaped steel at the tip end of the core material; The shear connector is a core member that is a structural steel or a square pipe whose axis extends perpendicular to the longitudinal direction of the H-shaped steel.

2. The shear connector has a plurality of flat plate portions that are perpendicular to each other, The core of claim 1 , wherein at least one of the plurality of plate portions extends perpendicular to a surface of the web.

3. The core of claim 1 , wherein the axis of the shear connector extends perpendicular to a surface of the web.

4. The core member according to claim 3 , wherein the shear connector is an angled steel beam having two flat plate portions that are perpendicular to each other and are welded with the corners facing downward.

5. The core material according to claim 1 , wherein the shear connector has a plurality of flat plate portions that are perpendicular to each other, and an outer surface of one of the plurality of flat plate portions is welded in a state of being in close contact with the surface of the web.

6. soil cement, which is created by mixing and stirring soil and cement and whose lower end is located within the bearing layer; A retaining wall having a core material according to any one of claims 1 to 5, which is inserted into the soil cement with the tip facing downward until the tip is positioned within the supporting layer.

7. A composite wall that serves as the underground exterior wall of the building frame, The retaining wall according to claim 6; a plurality of headed studs each having one end fixed to a flange of the H-shaped steel exposed from the soil cement on the upper side of the retaining wall; a concrete wall constructed to be integrated into the retaining wall by connecting rebar to the headed studs.

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