Wall construction core material and construction method

Abstract

To provide a core material for constructing a wall body and a construction method that enable efficient erection.SOLUTION: A core material for constructing a wall body is embedded in a cement-based material before the cement-based material filled in a wall hole hardens. The core material for constructing a wall body comprises: a steel material portion 20 extending in one direction; a cuttable portion 10 connected to one end of the steel material portion 20; and a weight portion 30 attached to the steel material portion 20 and extending in one direction A1 at least on the opposite side from the cuttable portion 10 of the steel material portion 20.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a wall construction core material and construction method that is built into a cementitious material filled into a hole wall. [Background technology]

[0002] Japanese Patent No. 5133450 describes a method for constructing an underground continuum. In the underground continuum construction method, a wall is constructed underground using an underground continuum construction device. In this underground continuum construction method, a rotary cutter of the underground continuum construction device is inserted into the ground. Then, the rotary cutter is rotated to cut the ground and form a continuous trench in the horizontal direction. At this time, drilling fluid is injected into the ground where the trench is to be formed and stirred and mixed by the rotary cutter, and multiple core materials are inserted into the inside of the trench to construct the underground continuum.

[0003] Japanese Patent No. 3659826 describes the TRD method (soil cement diaphragm wall method). In the TRD method, a base machine that can move on the ground surface and is equipped with a chainsaw-type cutter and a cutter post is used. The chainsaw-type cutter forms a trench by rotating the cutter post and pressing it against the ground. At this time, excavation mud is discharged from the ground grouting material discharge port provided at the bottom end of the cutter post to assist in excavating the trench, and further, ground solidification liquid is discharged and mixed with the excavated soil to build a soil cement wall.

[0004] Japanese Patent No. 5513182 describes a staged solidification method. In the staged solidification method, a TRD excavation rig is used. The TRD excavation rig excavates to form a trench, and a solidification liquid is supplied to the trench. Before the solidification liquid solidifies, a core material such as steel material including H-shaped steel is placed in the solidification liquid.

[0005] JP 2004-360241 A describes a method for constructing a steel diaphragm wall. In this method, a horizontal trench is formed in the ground by excavation, and a soil improvement body made of soil cement is filled into the trench. Then, steel diaphragm wall elements made of steel are inserted into the soil improvement body to construct the steel diaphragm wall. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5133450 [Patent Document 2] Patent No. 3659826 [Patent Document 3] Patent No. 5513182 [Patent Document 4] JP 2004-360241 A Summary of the Invention [Problem to be solved by the invention]

[0007] In each of the above-mentioned construction methods, a core material such as a steel material is inserted before the cement-based material such as the ground improvement body hardens. Some core materials are known to have a cuttable part that can be cut directly by a shield machine. This type of core material can be cut directly by the cutter bit of the shield machine, so wear of the cutter bit during cutting is suppressed.

[0008] However, since the cuttable portion of the core material has a smaller specific gravity than the steel material, it may not be possible to insert the core material efficiently into the cement-based material. In other words, when the core material is inserted into the cement-based material, the core material may move laterally due to buoyancy, so there is room for improvement in terms of efficiency of insertion.

[0009] An object of the present disclosure is to provide a core material for wall construction and a construction method that enable efficient erection. [Means for solving the problem]

[0010] The wall construction core material according to the present disclosure is a core material for wall construction that is built into the cement-based material filled in the hole wall before the cement-based material hardens. The wall construction core material includes a steel part extending in one direction, a cuttable part connected to one end of the steel part, and a weight part attached to the steel part and extending in one direction on at least the side opposite the cuttable part of the steel part.

[0011] This wall construction core material has a steel part extending in one direction and a cuttable part connected to one end of the steel part. Therefore, after the wall construction core material is erected in the cement-based material before hardening, it is possible to cut the cuttable part of the wall construction core material by a shield machine. In addition, the wall construction core material has a weight part attached to the steel part, and the weight part is provided on at least the opposite side of the steel part from the cuttable part. Therefore, when the wall construction core material is erected with the steel part facing downward relative to the cuttable part, the weight part is located at least on the lower side of the steel part, so that the effect of buoyancy when the wall construction core material is inserted into the cement-based material can be reduced. In other words, since the wall construction core material is erected in a state where the weight part is provided at least on the lower side of the steel part, the overall specific gravity of the wall construction core material can be increased, and the lateral movement of the wall construction core material due to buoyancy can be suppressed. Furthermore, the weight part is attached to the steel part so as to extend along one direction. Therefore, when the core material for wall construction is inserted into the cementitious material in one direction, the insertion resistance due to the weight portion can be reduced, and as a result, the core material for wall construction can be erected more efficiently.

[0012] The steel part may have a side surface extending in one direction, and the weight part may be a steel plate-like member fixed to the side surface so as to fit along the side surface. In this case, since the steel plate-like member is attached as the weight part so as to fit along the side surface of the steel part extending in one direction, the insertion resistance of the weight part when inserting the wall construction core material into the cement-based material can be further reduced. Therefore, the wall construction core material can be erected more efficiently.

[0013] In the method for constructing a core material for wall construction according to the present disclosure, the core material for wall construction has a steel part extending in one direction and a cuttable part connected to one end of the steel part. The method for constructing the core material for wall construction includes the steps of forming a hole wall by drilling, filling the hole wall with a cement-based material, attaching a weight part to the steel part, and erecting the core material for wall construction into the cement-based material with the steel part facing downward with respect to the cuttable part before the cement-based material hardens.

[0014] In this method for constructing a core material for wall construction, a core material for wall construction is used that has a steel part extending in one direction and a cuttable part connected to one end of the steel part. Therefore, after the core material for wall construction is erected in the cement-based material, the cuttable part of the core material for wall construction can be cut by a shield machine. In this construction method, a weight part is attached to the steel part. Therefore, when the core material for wall construction is erected with the steel part facing downward relative to the cuttable part, the weight part is located below the core material for wall construction, so that the effect of buoyancy when the core material for wall construction is inserted into the cement-based material can be reduced. Therefore, the core material for wall construction is erected with the weight part attached to the steel part, so that the overall specific gravity of the core material for wall construction can be increased and the lateral movement of the core material for wall construction due to buoyancy can be suppressed. Therefore, the core material for wall construction can be erected more efficiently.

[0015] In the process of forming the hole wall, the excavator may be moved along the in-plane direction of the wall to perform excavation, and a hole wall extending continuously along the in-plane direction may be formed. In this case, it is possible to construct a continuous wall in the ground by moving the excavator in the horizontal direction using the TRD method. Therefore, a diaphragm wall with horizontal continuity can be constructed. In addition, since the TRD method forms a continuous hole wall extending horizontally, when the wall construction core material is inserted into the cement-based material, the wall construction core material may move in the horizontal direction. However, since the above-mentioned wall construction core material has a weight portion attached to the steel portion, the lateral movement of the wall construction core material in the horizontal direction can be suppressed. As a result, even when the hole wall is formed by the TRD method, the lateral movement of the wall construction core material can be suppressed, so that the wall construction core material can be erected more efficiently. Effect of the Invention

[0016] According to the present disclosure, erection can be carried out efficiently. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a diagram showing an example of a site where the wall construction core material and construction method according to the present embodiment are applied. [Diagram 2] 2(a) is a side view showing a cuttable portion of the core material for wall construction according to the present embodiment, and (b) is a side view of the core material for wall construction according to the present embodiment, seen from a different direction from that shown in FIG. [Diagram 3] 2(a) is a cross-sectional view taken along line AA in FIG. 2(b), and FIG. 2(b) is a cross-sectional view taken along line BB in FIG. [Figure 4] 2(b) is a cross-sectional view taken along line CC in FIG. 2(b), and FIG. 2(b) is a cross-sectional view taken along line DD in FIG. [Diagram 5] 2 is a side view showing the steel part and the weight part of the wall construction core material according to the present embodiment. FIG. [Figure 6] 6 is a view of the steel part and the weight part in FIG. 5, seen from a different direction than in FIG. 5. [Figure 7]1A, 1B, and 1C are diagrams illustrating an example of steps of a construction method according to the present embodiment. [Figure 8] 1A and 1B are diagrams illustrating an example of steps of a construction method according to the present embodiment. [Figure 9] 9(a) is a side view showing a steel part and a weight part of a wall construction core material according to a modified example, and FIG. 9(b) is a view showing the steel part and the weight part of FIG. 9(a) from a different direction than FIG. 9(a). [Figure 10] 13 is a graph showing experimental results for the wall construction core material according to the embodiment. [Figure 11] 13(a), (b), and (c) are diagrams illustrating an embodiment in which the shape and weight of a weight part are calculated from a restoring force calculation due to a moment. [Figure 12] 1 is a table showing the results of the examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of a wall construction core material and a construction method according to the present disclosure will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are given the same reference numerals, and duplicated descriptions are omitted as appropriate. In addition, the drawings may be partially simplified or exaggerated for ease of understanding, and the dimensional ratios and the like are not limited to those shown in the drawings.

[0019] Fig. 1 shows an exemplary site A to which a wall construction core material 1 and a construction method according to the present embodiment are applied. At the site A, a shield tunnel S is constructed. As an example, a shield machine that constructs the shield tunnel S starts from a starting shaft, excavates, and rotates in a rotating shaft. As an example, the rotating shaft is constructed at the site A.

[0020] At the site A where the rotating shaft is to be constructed, for example, a plurality of wall construction core materials 1 are erected by the TRD method. In the TRD method, for example, a chainsaw-type cutter post inserted into the ground is connected to a base machine, and the cutter post and the base machine move in the horizontal direction D1 (lateral direction) to form a hole wall (trench) by excavation and to inject a solidification liquid into the hole wall. Then, after the solidification liquid and the in-situ soil are mixed and stirred, the wall construction core materials 1 are inserted into the hole wall to construct an underground wall.

[0021] As an example, the wall construction core material 1 includes FFU (Fiber reinforced foamed urethane). FFU is a structural material obtained by foaming and thermally expanding urethane impregnated with glass fibers. In other words, FFU is a lightweight corrosion-resistant structural material in which a thermosetting resin foam (rigid urethane resin) is reinforced with long glass fibers. The wall construction core material 1 including FFU is also called SEW (Shield Earth Retaining Wall).

[0022] Compared to other wall construction core materials, the SEW wall construction core material 1 can reduce the amount of opening work required, ensuring safety and being economical. Furthermore, the SEW wall construction core material 1 has excellent machinability because the FFU functions as the cuttable portion, making cutting easy.

[0023] However, the specific gravity of the SEW wall construction core material is smaller than that of other wall construction core materials (e.g., steel materials). Therefore, when the SEW wall construction core material is inserted into a cement-based material and erected, the wall construction core material may move laterally due to buoyancy. Furthermore, the wall construction core material may move laterally due to the lateral movement of the excavator that excavates the ground and forms the hole wall.

[0024] In particular, at the site A where many wall construction core materials are erected along the horizontal direction D1, the above problems make it difficult to efficiently erect the wall construction core materials. In contrast, the wall construction core material 1 and construction method according to this embodiment can solve these problems.

[0025] For example, the wall construction core material 1 has a cuttable portion 10 and a steel portion 20 aligned along the vertical direction D2. The cuttable portion 10 can be cut by a shield machine. For example, the cuttable portion 10 is provided above the steel portion 20. The lengths of the cuttable portions 10 and the steel portions 20 differ among a plurality of wall construction core materials 1. For example, the specific gravity of the cuttable portions 10 is smaller than the specific gravity of the steel portions 20.

[0026] Fig. 2(a) is an enlarged side view of the cuttable portion 10. Fig. 2(b) is a side view of the cuttable portion 10 seen from a different direction than that of Fig. 2(a). As shown in Fig. 2(a) and Fig. 2(b), the cuttable portion 10 has a rod shape extending in one direction A1. The wall construction core material 1 is erected with the one direction A1 of the cuttable portion 10 coinciding with the vertical direction D2.

[0027] As an example, the cuttable portion 10 includes a first connecting portion 11 located at one end in one direction A1, a first cuttable portion 12, a second cuttable portion 13, a third cuttable portion 14, a second connecting portion 15, and a third connecting portion 16. The first connecting portion 11, the first cuttable portion 12, the second cuttable portion 13, the third cuttable portion 14, the second connecting portion 15, and the third connecting portion 16 are arranged in this order along the one direction A1.

[0028] For example, the first connecting portion 11 is a portion located at the upper end of the cuttable portion 10. The first connecting portion 11 has a first plate portion 11b that constitutes an end portion of the cuttable portion 10, and a second plate portion 11c that is connected to the first cuttable portion 12. The first plate portion 11b has a triangular shape whose length in the direction A2 decreases with increasing distance from the first cuttable portion 12.

[0029] The direction A2 is a direction intersecting (for example, perpendicular to) the one direction A1, for example, the width direction of the cuttable portion 10. For example, the corner 11d located at the end of the first plate portion 11b opposite to the first cuttable portion 12 is rounded. The first plate portion 11b also has a hole 11f penetrating in a direction A3 intersecting both the one direction A1 and the direction A2.

[0030] FIG. 3(a) is a diagram showing a cross section of the second plate portion 11c and the first cuttable portion 12 when cut along a plane perpendicular to one direction A1 (a cross section along line AA in FIG. 2(b)). As shown in FIG. 2(b) and FIG. 3(a), when viewed along direction A3, for example, the second plate portion 11c has a rectangular shape with long sides extending in direction A2. The second plate portions 11c are provided on both sides of the first cuttable portion 12 in direction A3. Each of the pair of second plate portions 11c aligned along direction A3 has a bolt hole 11j.

[0031] The pair of second plate portions 11c are fixed to the first cuttable portion 12 by fastening the bolts 11g, which pass through the bolt holes 11j of the pair of second plate portions 11c and the first cuttable portion 12, with the nuts 11h. A plurality of bolts 11g are lined up along the direction A2, and as an example, the number of bolts 11g is three.

[0032] Figure 3(b) shows a cross section 12b of the first cuttable portion 12 when the first cuttable portion 12 is cut along a plane perpendicular to the direction A1 (cross section of line BB in Figure 2(b)). As shown in Figures 2(a), 2(b) and 3(b), for example, the first cuttable portion 12 is an FFU member made of FFU. As an example, the first cuttable portion 12 is made only of FFU. For example, the specific gravity of the first cuttable portion 12 is 1.0 or less.

[0033] The cross section 12b has a rectangular shape having, for example, a long side 12c extending in the direction A2 and a short side 12d extending in the direction A3. For example, the area of ​​the cross section 12b is larger than the area of ​​the cross section of the steel part 20 when the steel part 20 is cut along a plane perpendicular to the one direction A1. As an example, the length of the long side 12c is 700 mm, and the length of the short side 12d is 240 mm.

[0034] Fig. 4(a) is a cross-sectional view of the second cuttable portion 13 when the second cuttable portion 13 is cut along a plane perpendicular to the one direction A1 (cross-sectional view of line CC in Fig. 2(b)). As shown in Figs. 2(a), 2(b) and 4(a), the second cuttable portion 13 has, for example, an FFU portion 13b which is a portion composed only of an FFU, a sheet member 13c which covers at least a portion of the FFU portion 13b, and a fixing member 13d which fixes the sheet member 13c to the FFU portion 13b.

[0035] For example, the FFU unit 13b is provided on an extension of the first cuttable unit 12 in one direction A1. The sheet member 13c is, for example, a resin sheet. As an example, the sheet member 13c is a GFRP (Glass Fiber Reinforced Plastic) sheet. In this case, the sheet member 13c is made of a material (GFRP) in which glass fibers are solidified with polyester resin, vinyl ester resin, epoxy resin, or phenol resin. As an example, the sheet member 13c is provided on each of both sides of the FFU unit 13b in the direction A3.

[0036] The fixing member 13d has, for example, a bolt 13f penetrating the FFU portion 13b and the pair of sheet members 13c, and a nut 13g that tightens the bolt 13f to the sheet member 13c. When viewed along the direction A3, the second cuttable portion 13 is provided with a plurality of fixing members 13d (a plurality of bolts 13f and a plurality of nuts 13g). The third cuttable portion 14 is, for example, an FFU member, similar to the first cuttable portion 12. As an example, the configuration of the third cuttable portion 14 is the same as the configuration of the first cuttable portion 12.

[0037] FIG. 4(b) is a cross-sectional view of the second connection part 15 when the second connection part 15 is cut along a plane perpendicular to the one direction A1 (cross-sectional view of line DD in FIG. 2(b)). As shown in FIG. 2(a), FIG. 2(b) and FIG. 4(b), the second connection part 15 has an FFU part 15b composed only of an FFU, a first steel plate 15c extending in the one direction A1 and the direction A2 inside the FFU part 15b, and a second steel plate 15d located on each side of the first steel plate 15c in the direction A3 inside the FFU part 15b. For example, the first steel plate 15c extends in the direction A2 at the center of the direction A3 of the second connection part 15. The second steel plate 15d extends in the one direction A1 and the direction A2. As an example, the thickness of the first steel plate 15c is thicker than the thickness of the second steel plate 15d.

[0038] The second connection part 15 has a third steel plate 15f provided on each side of the FFU part 15b in the direction A3, and a fourth steel plate 15g provided on each side of the FFU part 15b in the direction A2. Each of the third steel plate 15f, the second steel plate 15d, and the first steel plate 15c has a through hole 15h extending in the direction A3, and a bolt 15j is inserted into the through hole 15h.

[0039] The bolt 15j is fastened to the third steel plate 15f by a nut 15k. For example, two through holes 15h, two bolts 15j, and two nuts 15k are provided along the direction A2. For example, the first steel plate 15c has flanges 15m at both ends in the direction A2. The fourth steel plate 15g extends in one direction A1 when placed on the flanges 15m, the second steel plate 15d, and the third steel plate 15f.

[0040] The third connection part 16 is a part located at the lower end of the cuttable part 10, and is connected to the steel part 20. As an example, the third connection part 16 has a pair of fifth steel plates 16b connected to the second connection part 15 and aligned along the direction A2, and a sixth steel plate 16c extending in the direction A1 and the direction A2 between the pair of fifth steel plates 16b. For example, the third connection part 16 has a pair of tapered steel plates 16d extending from the sixth steel plate 16c so as to be inclined with respect to the direction A1. The pair of tapered steel plates 16d are inclined in directions moving away from each other as they approach the second connection part 15.

[0041] The above describes an example in which the cuttable portion 10 includes the first connecting portion 11, the first cuttable portion 12, the second cuttable portion 13, the third cuttable portion 14, the second connecting portion 15, and the third connecting portion 16. However, the configuration of the cuttable portion is not limited to the above-mentioned first connecting portion 11, the first cuttable portion 12, the second cuttable portion 13, the third cuttable portion 14, the second connecting portion 15, and the third connecting portion 16, and can be changed as appropriate.

[0042] Fig. 5 is a side view showing the steel part 20 connected to the cuttable part 10. As shown in Fig. 5, the steel part 20 extends in one direction A1, and is provided on an extension of the third connection part 16 of the cuttable part 10. For example, the steel part 20 has a connection part 21 connected to the cuttable part 10 (third connection part 16), and a steel main body part 22 extending from the connection part 21 to the opposite side to the cuttable part 10 (left side in Fig. 5).

[0043] The connection portion 21 has, for example, a plurality of splice plates 21b that are attached to the third connection portion 16 and the steel main body portion 22, a plurality of first bolt nuts 21c that fasten the splice plates 21b to the third connection portion 16, and a plurality of second bolt nuts 21d that fasten the splice plates 21b to the steel main body portion 22.

[0044] For example, the steel body 22 is an H-shaped steel. In this case, the steel body 22 has a pair of flanges 22b extending in one direction A1 and in the direction A3 and aligned along the direction A2, and a web 22c connecting the pair of flanges 22b to each other and extending in the one direction A1 and in the direction A2. The splice plate 21b extending from the cuttable portion 10 is attached to each of the pair of flanges 22b and the web 22c, and the splice plate 21b is joined to the steel body 22 by a plurality of second bolt nuts 21d, thereby connecting the steel part 20 to the cuttable portion 10.

[0045] Figure 6 is a view of the steel part 20 viewed from the opposite side to the cuttable part 10. As shown in Figures 5 and 6, a weight part 30 is attached to the steel part 20. The weight part 30 extends along one direction A1 at least on the opposite side of the steel part 20 to the cuttable part 10 (the left side in Figure 5).

[0046] The total weight of the weight portion 30 is, for example, 2000 kg or more and 3000 kg or less. When the total weight of the weight portion 30 is 2000 kg or more, lateral movement of the wall construction core material 1 can be more reliably suppressed. When the total weight of the weight portion 30 is 3000 kg or less, the total weight of the weight portion 30 can be prevented from becoming too heavy. As an example, the total weight of the weight portion 30 is 2506 kg. However, the value of the total weight of the weight portion 30 is not particularly limited.

[0047] For example, the steel part 20 has a side surface 22d extending along one direction A1. As an example, the side surface 22d is a surface of the web 22c, and is provided on each of both sides of the steel part 20 in the direction A3. A weight part 30 is attached to each of a pair of side surfaces 22d aligned along the direction A3. That is, a weight part 30 is attached to each of one side surface 22d and the other side surface 22d of the web 22c. In this manner, a plurality of weight parts 30 are attached to the steel part 20. For example, the plurality of weight parts 30 are attached to the steel part 20 so as to be aligned along the one direction A1. In the example of FIG. 5, four weight parts 30 are aligned along the one direction A1. However, the number of weight parts 30 attached to the steel part 20 is not particularly limited.

[0048] The wall construction core material 1 includes fastening members 31 that fasten the weight portion 30 to the steel material portion 20. For example, the steel material portion 20 has a through hole 23 through which the fastening member 31 passes, and the weight portion 30 has a through hole 32 through which the fastening member 31 passes. The through hole 23 and the through hole 32 each pass through the steel material portion 20 (web 22c) and the weight portion 30 in the direction A3.

[0049] For example, the weight 30 is a plate-like member fixed to the side surface 22d so as to extend along the side surface 22d. As an example, the weight 30 is attached to the steel part 20 in a state in which the thickness direction of the weight 30 coincides with the thickness direction of the side surface 22d (web 22c). For example, the weight 30 has a rectangular shape having long sides extending in one direction A1.

[0050] For example, the weight portion 30 has a main surface 30b exposed to the outside of the wall construction core material 1, a pair of first end faces 30c facing in a direction intersecting with the main surface 30b, and a pair of second end faces 30d facing in a direction intersecting with both the main surface 30b and the first end faces 30c. As an example, the area of ​​the main surface 30b is larger than the area of ​​the first end faces 30c, and the area of ​​the first end faces 30c is larger than the area of ​​the second end faces 30d.

[0051] For example, the weight portion 30 is attached to the steel part 20 with the first end face 30c facing the direction A2 and the second end face 30d facing the direction A1. In this case, the weight portion 30 is attached to the steel part 20 with the second end face 30d, which has the smallest area, facing the direction A1, so that the insertion resistance of the weight portion 30 when the wall construction core material 1 is inserted in the direction A1 can be further reduced.

[0052] As an example, the weight portion 30 has a plurality of through holes 32 to which fastening members 31 are joined at each corner of the weight portion 30 when the weight portion 30 is viewed from the plate thickness direction. For example, each through hole 32 is formed at each of the four corners of the weight portion 30. For example, the fastening member 31 includes a bolt 31b that is passed through the through hole 23 and the through hole 32, and a nut 31c that fastens the bolt 31b that is passed through the through hole 23 and the through hole 32 to the weight portion 30. The wall construction core material 1 includes, for example, a plurality of fastening members 31. The plurality of fastening members 31 are aligned along one direction A1 and also along the direction A2.

[0053] Next, an example of a method for constructing a core material for wall construction according to this embodiment will be described with reference to Figures 7(a), 7(b), 7(c), 8(a) and 8(b). Below, an example of constructing a wall (underground wall) by erecting a core material for wall construction 1 into the ground G by the TRD method will be described. As an example, three-pass construction of the TRD method may be performed.

[0054] First, as shown in Fig. 7(a), an excavator X is prepared (step of preparing an excavator). Note that in Figs. 7(a), 7(b), 7(c), 8(a) and 8(b), the illustration of the excavator X and the wall construction core material 1 is simplified. For example, the excavator X has an equipment body X1, a cutter bit X2 that extends vertically downward from the equipment body X1 and moves in a circulating manner along the vertical direction D2, and an injection part X3 that injects a solidification liquid into the ground G. The injection part X3 is provided at the tip (lower end) of the cutter bit X2.

[0055] As shown in Figures 7(a) and 7(b), a hole wall 41 is formed by excavation (a step of forming a hole wall). As a specific example, the cutter bit X2 is inserted into the ground G so that the cutter bit X2 is aligned along the vertical direction D2. Then, the cutter bit X2 inserted into the ground G is circulated to excavate the ground G and remove soil, and the device body X1 is moved in the horizontal direction D1 (lateral direction).

[0056] As the hole wall 41 is formed, the hole wall 41 is filled with a cement-based material 42 (a process of filling the hole wall 41 with a cement-based material). As a specific example, as the hole wall 41 is formed as described above, a solidification liquid (cement-based slurry or the like) is injected into the hole wall 41 from the injection part X3, and the solidification liquid is mixed and stirred together with the excavated ground G (in-situ soil) to construct a soil cement wall that is continuous in the horizontal direction D1.

[0057] On the other hand, a wall construction core material 1 is prepared (a process of preparing a wall construction core material). At this time, the weight portion 30 is attached to the steel portion 20 by, for example, the method described above (a process of attaching the weight portion). Then, as shown in Fig. 7(c), before the cement-based material 42 hardens, the wall construction core material 1 is erected into the cement-based material 42 with the steel portion 20 (weight portion 30) facing downward relative to the cuttable portion 10 (a process of erecting the wall construction core material).

[0058] As shown in Figures 8(a) and 8(b), a plurality of wall construction core materials 1 are inserted into the cementitious material 42 so as to be aligned along the horizontal direction D1, and are erected into the hole wall 41. Then, after retreat excavation and lap construction are performed and the cementitious material 42 hardens, a series of steps relating to erecting the wall construction core materials 1 is completed.

[0059] Next, the effects obtained from the wall construction core material 1 and construction method according to this embodiment will be described. As shown in Figures 5 and 6, the wall construction core material 1 and construction method according to this embodiment have a steel part 20 extending in one direction A1 and a cuttable part 10 connected to one end of the steel part 20. Therefore, after erecting the wall construction core material 1 in the cementitious material 42 before hardening, it is possible to cut the cuttable part 10 of the wall construction core material 1 by a shield machine.

[0060] The wall construction core material 1 also includes a weight 30 attached to the steel material portion 20, and the weight 30 is provided on at least the side of the steel material portion 20 opposite to the cuttable portion 10. The weight 30 may be provided on substantially the entire surface of the steel material portion 20. Therefore, when the wall construction core material 1 is erected with the steel material portion 20 facing downward relative to the cuttable portion 10, the weight 30 is located at least below the steel material portion 20, so that it is possible to reduce the effect of buoyancy when the wall construction core material 1 is inserted into the cement-based material 42. In this embodiment, it is possible to use, as the cement-based material 42, a material with a table flow value larger than the current one (for example, about 240 mm).

[0061] That is, since the wall construction core material 1 is erected with the weight portion 30 provided at least on the lower side of the steel portion 20, the overall specific gravity of the wall construction core material 1 can be increased, suppressing lateral movement of the wall construction core material 1 due to buoyancy. Furthermore, the weight portion 30 is attached to the steel portion 20 so as to extend along one direction A1. Therefore, when the wall construction core material 1 is inserted into the cement-based material 42 along the one direction A1, the insertion resistance of the weight portion 30 can be reduced. As a result, the wall construction core material 1 can be erected more efficiently.

[0062] In this embodiment, the steel part 20 has a side surface 22d extending along one direction A1, and the weight part 30 is a steel plate-like member fixed to the side surface 22d so as to be aligned with the side surface 22d. Therefore, since the steel plate-like member is attached as the weight part 30 so as to be aligned with the side surface 22d of the steel part 20 extending along one direction A1, the insertion resistance of the weight part 30 when the wall construction core material 1 is inserted into the cement-based material 42 can be further reduced. Therefore, the wall construction core material 1 can be erected more efficiently.

[0063] 7(a) to 7(c), in the construction method according to this embodiment, in the step of forming the hole wall 41, the excavator X is moved along the in-plane direction of the wall body while excavating with the excavator X, and the hole wall 41 that extends continuously along the in-plane direction is formed. Therefore, it is possible to construct a continuous wall in the ground by moving the excavator X in the horizontal direction D1 by the TRD method.

[0064] Therefore, an underground wall with continuity in the horizontal direction D1 can be constructed. In addition, in the TRD method, a continuous hole wall 41 extending in the horizontal direction D1 is formed, so that when the wall construction core material is inserted into the cement-based material 42, the wall construction core material may move in the horizontal direction D1. However, since the weight portion 30 is attached to the steel portion 20 of the wall construction core material 1, the lateral movement of the wall construction core material 1 in the horizontal direction D1 can be suppressed. As a result, even when the hole wall 41 is formed by the TRD method, the lateral movement of the wall construction core material 1 can be suppressed, so that the wall construction core material 1 can be erected more efficiently.

[0065] Next, a modified core material for wall construction will be described with reference to Figs. 9(a) and 9(b). Fig. 9(a) is a side view showing a steel part 50 of the modified core material for wall construction. Fig. 9(b) is a side view of the steel part 50 seen from a different direction than Fig. 9(a). The modified core material for wall construction has a steel part 50 different from the steel part 20 described above. A portion of the configuration of the modified core material for wall construction is the same as a portion of the configuration of the core material for wall construction 1 described above. Therefore, in the following, the same reference numerals are used for parts that overlap with the configuration of the core material for wall construction 1, and the description will be omitted as appropriate.

[0066] The steel part 50 has a connection part 21 and a steel main body part 22, similar to the steel part 20, and the steel main body part 22 has a pair of flanges 22b and a web 22c. A weight part 60 different from the weight part 30 described above is attached to the steel part 50. The weight part 60 extends along one direction A1 on the side opposite to the cuttable part 10 of the steel part 50.

[0067] For example, weight portion 60 is composed of a plurality of plate-like members arranged along direction A3. The plate-like members constituting weight portion 60 are fixed to steel material portion 50 so as to be aligned with steel material portion 50. That is, the plate-like members constituting weight portion 60 are attached to steel material portion 50 in a state in which the plate thickness direction of the plate-like members coincides with the plate thickness direction of steel material portion 50 (web 22c).

[0068] As an example, the multiple weight portions 60 include two first plate-shaped members 61, two second plate-shaped members 62, two third plate-shaped members 63, and two fourth plate-shaped members 64. The fourth plate-shaped member 64 is attached to a side surface (a surface of the web 22c) of the steel material portion 50. The third plate-shaped member 63 is attached to the opposite side of the steel material portion 50 from the fourth plate-shaped member 64, and the second plate-shaped member 62 is attached to the opposite side of the fourth plate-shaped member 64 from the third plate-shaped member 63. And the first plate-shaped member 61 is attached to the opposite side of the third plate-shaped member 63 from the second plate-shaped member 62.

[0069] The wall construction core material according to the modified example includes fastening members 65 that fasten the weight portion 60 to the steel material portion 50. The first plate-shaped member 61, the second plate-shaped member 62, the third plate-shaped member 63, the fourth plate-shaped member 64 and the steel material portion 50 (web 22c) each have a through hole through which the fastening member 65 passes. The fastening member 65 has a bolt and a nut, similar to the fastening member 31 described above, and the bolt of the fastening member 65 that is passed through the through hole is fastened to the weight portion 60 by the nut. This makes it possible to fix a plurality of weight portions 60 to the steel material portion 50.

[0070] As an example, among the multiple weight sections 60, the first plate-shaped member 61 is located at the outermost position in the direction A3, and the second plate-shaped member 62 is located at the second outermost position in the direction A3. Among the multiple weight sections 60, the fourth plate-shaped member 64 is located at the innermost position in the direction A3, and the third plate-shaped member 63 is located at the second innermost position in the direction A3. That is, the fourth plate-shaped member 64 is in contact with the steel section 20, and the third plate-shaped member 63 is in contact with the fourth plate-shaped member 64. Then, the second plate-shaped member 62 is in contact with the third plate-shaped member 63, and the first plate-shaped member 61 is in contact with the second plate-shaped member 62.

[0071] The length of the first plate-shaped member 61 in the one direction A1 is shorter than the length of the second plate-shaped member 62 in the one direction A1, and the length of the second plate-shaped member 62 in the one direction A1 is shorter than the length of the third plate-shaped member 63 in the one direction A1. The length of the third plate-shaped member 63 in the one direction A1 is shorter than the length of the fourth plate-shaped member 64 in the one direction A1. In other words, in terms of the length in the one direction A1, the fourth plate-shaped member 64 is the longest, the third plate-shaped member 63 is the second longest, the second plate-shaped member 62 is the third longest, and the first plate-shaped member 61 is the shortest.

[0072] For example, the end faces of the first plate-shaped member 61, the second plate-shaped member 62, the third plate-shaped member 63, and the fourth plate-shaped member 64 on the cuttable portion 10 side (the right side in Figs. 9(a) and 9(b)) are aligned. Also, the end faces of the first plate-shaped member 61, the second plate-shaped member 62, the third plate-shaped member 63, and the fourth plate-shaped member 64 on the opposite side to the cuttable portion 10 (the left side in Figs. 9(a) and 9(b)) are misaligned with each other.

[0073] The end face of the second plate-shaped member 62 opposite the cuttable portion 10 protrudes from the end face of the first plate-shaped member 61 opposite the cuttable portion 10, and the end face of the third plate-shaped member 63 opposite the cuttable portion 10 protrudes from the end face of the second plate-shaped member 62 opposite the cuttable portion 10. And the end face of the fourth plate-shaped member 64 opposite the cuttable portion 10 protrudes from the end face of the third plate-shaped member 63 opposite the cuttable portion 10.

[0074] The fourth plate-shaped member 64 located at the center side in the direction A3 protrudes furthest on the side opposite the cuttable portion 10, and the third plate-shaped member 63 located second from the center side in the direction A3 protrudes second furthest on the side opposite the cuttable portion 10. The second plate-shaped member 62 located third from the center side in the direction A3 protrudes third furthest on the side opposite the cuttable portion 10. Therefore, the overall thickness of the multiple weight portions 60 becomes thicker from the end opposite the cuttable portion 10 toward the cuttable portion 10. This makes it possible to further reduce the insertion resistance of the weight portions 60 when the steel part 50 is inserted in one direction A1.

[0075] (Example) Next, an example of the wall construction core material according to the present disclosure will be described. Note that the present invention is not limited to the contents of the following examples. In the examples, a test construction of the wall construction core material 1 was carried out. In the test construction, as described above, the hole wall 41 was formed by the drilling machine X, and a drilling fluid (first mixed fluid) containing bentonite and a construction fluid (second mixed fluid) containing cement were injected into the hole wall 41 to form a cement-based material 42. Meanwhile, the weight part 30 and the measuring pipe were attached to the wall construction core material 1, and the wall construction core material 1 was erected against the cement-based material 42, and the presence or absence of lateral movement of the wall construction core material 1 was measured.

[0076] An example of the results of the above measurements is shown in FIG. 10. FIG. 10 shows the horizontal movement of the wall construction core material 1 after erection when the upper end of the wall construction core material 1 is fixed. The vertical axis of the graph in FIG. 10 shows the depth of the ground G, and the horizontal axis of the graph in FIG. 10 shows the displacement in the horizontal direction D1. As shown in FIG. 10, the lower end of the wall construction core material 1 moved from -95 mm to -107 mm between the completion of erection and the start of the evacuation horizontal movement. And, the lower end of the wall construction core material 1 moved from -95 mm to -72 mm between the end of the evacuation horizontal movement and the start of the pull-out. As described above, it was found that the lateral movement of the wall construction core material 1 to which the weight portion 30 is attached can be suppressed to about several centimeters.

[0077] Next, an embodiment of a method for calculating the shape and weight of the weight portion 30 will be described with reference to Figures 11(a), 11(b), 11(c), and 12. Below, a method for calculating the shape and weight of the weight portion by calculating the restoring force due to the moment will be described. Specifically, the force (restoring force) with which the FFU core material moves laterally to return to its original state was calculated, and this restoring force was compared.

[0078] Figure 11(a) shows a general part consisting of only H-shaped steel without a weight and FFU, Figure 11(b) shows a SEW wall part having an H-shaped steel and FFU, and Figure 11(c) shows a SEW wall part having an H-shaped steel, FFU, and weight. As shown in Figures 11(a) and 11(b), since the specific gravity of the FFU is smaller than that of the H-shaped steel, the position of the center of gravity GB of the SEW wall part is higher than the center of gravity GA of the general part. As shown in Figures 11(b) and 11(c), when the weight is attached to the lower end of the H-shaped steel, the positions of the center of gravity GC and center of buoyancy CC are lower than the center of gravity GB and center of buoyancy CB of the SEW wall without a weight.

[0079] Since the position of the center of buoyancy is affected by the weight of the core in the soil mortar, the restoring force was evaluated as the force that causes the core to return to its normal position as the rotational moments MA, MB, and MC at the top end of the core. MA is the rotational moment of the general part, MB is the rotational moment of the SEW wall part without a weight, and MC is the rotational moment of the SEW wall part with a weight attached. MA, MB, and MC are calculated using the following formulas. MA = La × Wh-La' × Vh × ρs MB=Lb×(W1+W2+W3+W4-ww)-Lb'×(V1+V2+V3+V4-vw)×ρs MC=Lc×(W1+W2+W3+W4)-Lc'×(V1+V2+V3+V4)×ρs In the above formula, ρs is the density of the soil cement, which is 1650 kg / m in this embodiment. 3 (1.65). In addition, h is the H-steel length (total length), h1 is the H-steel length (upper part), h2 is the FFU length, h3 is the H-steel length (lower part), h4 is the H-steel length (weight part), Wh is the H-steel weight (total length), W1 is the H-steel weight (upper part), W2 is the FFU weight, W3 is the H-steel weight (lower part), W4 is the H-steel weight (weight part), ww is the weight of the weight part, Vh is the H-steel volume (total length), V1 is the H-steel volume (upper part), V2 is the FFU volume, V3 is the H-steel volume (lower part), V4 is the H-steel volume (weight part), and vw is the weight of the weight part.

[0080] Furthermore, if the distance from the upper end of the core material in the general part to the center of gravity of the core material is La, the distance from the upper end of the core material in the SEW wall without a weight part to the center of gravity of the core material is Lb, and the distance from the upper end of the core material to the center of gravity of the core material in the SEW wall with a weight part attached is Lc, La, Lb and Lc are expressed by the following equations. La=h / 2 Lb={W1×h1 / 2+W2×(h1+h2 / 2)+(W3+W4-ww)×(h1+h2+(h3+h4) / 2} / (W1+W2+W3+W4-ww) Lc={W1×h1 / 2+W2×(h1+h2 / 2)+W3×(h1+h2+h3 / 2)+W4(h1+h2+h3+h4 / 2)} / (W1+W2+W3+W4)

[0081] Furthermore, if the distance from the upper end of the core material in the general part to the center of buoyancy of the core material is La', the distance from the upper end of the core material in the SEW wall without a weight part to the center of buoyancy of the core material is Lb', and the distance from the upper end of the core material in the SEW wall with a weight part attached to it is Lc', La', Lb' and Lc' are expressed by the following equation. La'=h / 2 Lb'={V1×ρs×h1 / 2+V2×ρs×(h1+h2 / 2)+(V3+V4-vw)×ρs×(h1+h2+(h3+h4) / 2)} / ((V1+V2+V3+V4-vw)×ρs) Lc'={V1×ρs×h1 / 2+V2×ρs×(h1+h2 / 2)+V3×ρs×(h1+h2+h3 / 2)+V4×ρs×(h1+h2+h3+h4 / 2)} / ((V1+V2+V3+V4)×ρs)

[0082] The conditions for the H-beam and FFU were as follows: Cross-sectional area of ​​H steel s = 0.023 (m 2 ), weight of H-beam w = 182 (kg / m), height of FFU Hf = 0.700 (m), width of FFU Bf = 0.240 (m), density of FFU ρf = 1000 kg / m 3 (1.00)

[0083] The results of calculating the restoring forces and the like for Examples 1 to 7 under the above conditions are shown in Figure 12. Examples 1 to 7 in Figure 12 are different from one another in terms of the weight conditions, member length, member weight, and member volume. Figure 12 shows that in order to make the rotation moment MC of the SEW wall with the weight attached higher than that of the general part and to satisfy MC≧MA, it is necessary to attach a weight that satisfies the weight conditions in Figure 12 to the H-steel.

[0084] The above describes the embodiment, modification, and example of the wall construction core material and construction method according to the present disclosure. However, the present disclosure is not limited to the above-mentioned embodiment, modification, or example, and may be further modified within the scope of the gist described in the claims. In other words, the configuration, shape, size, material, number, and arrangement of each part of the wall construction core material, as well as the content and order of the steps of the construction method, can be appropriately changed within the scope of the above gist.

[0085] For example, in the above embodiment, an example was described in which the steel material main body 22 of the steel material part 20 was an H-shaped steel. However, the steel material part may be a steel material other than an H-shaped steel, for example, a steel material having a box-shaped cross section. In this way, the type of steel material constituting the steel material part can be changed as appropriate.

[0086] For example, in the above-mentioned modified example, the multiple weight portions 60 include a first plate-shaped member 61, a second plate-shaped member 62, a third plate-shaped member 63, and a fourth plate-shaped member 64. However, the number of plate-shaped members of the weight portions may be one or more and three or less, or five or more, and can be changed as appropriate.

[0087] In the above embodiment, an example was described in which multiple wall construction core materials 1 were erected by the TRD method. However, the wall construction core materials may be erected by a method other than the TRD method. For example, the wall construction core materials may be erected by the SMW method (soil mixing wall method), and the wall construction core materials and construction methods according to the present disclosure are applicable to various construction methods. In the above embodiment, an example was described in which multiple wall construction core materials 1 were erected at a site A where a rotating shaft is constructed. However, the wall construction core materials and construction methods according to the present disclosure are not limited to the above-mentioned site A, and can be applied to various sites. [Explanation of symbols]

[0088] 1...wall construction core material, 10...cuttable portion, 11...first connection portion, 11b...first plate portion, 11c...second plate portion, 11d...corner portion, 11f...hole, 11g...bolt, 11h...nut, 11j...bolt hole, 12...first cuttable portion, 12b...cross section, 12c...long side, 12d...short side, 13...second cuttable portion, 13b...FFU portion, 13c...sheet member, 13d...fixing member, 13 f...bolt, 13g...nut, 14...third cuttable portion, 15...second connection portion, 15b...FFU portion, 15c...first steel plate, 15d...second steel plate, 15f...third steel plate, 15g...fourth steel plate, 15h...through hole, 15j...bolt, 15k...nut, 15m...flange portion, 16...third connection portion, 16b...fifth steel plate, 16c...sixth steel plate, 16d...tapered steel plate, 20...steel portion, 21...Connection portion, 21b...Splice plate, 21c...First bolt and nut, 21d...Second bolt and nut, 22...Steel body portion, 22b...Flange, 22c...Web, 22d...Side, 23...Through hole, 30...Plummet portion, 30b...Main surface, 30c...First end surface, 30d...Second end surface, 31...Fastening member, 31b...Bolt, 31c...Nut, 32...Through hole, 41...Hole wall, 42 ...Cementitious material, 50...Steel section, 60...Weight section, 61...First plate-shaped member, 62...Second plate-shaped member, 63...Third plate-shaped member, 64...Fourth plate-shaped member, 65...Fastening member, A...Site, A1...One direction, A2...Direction, A3...Direction, D1...Horizontal direction, D2...Vertical direction, G...Ground, S...Shield tunnel, X...Excavator, X1...Equipment body, X2...Cutter bit, X3...Injection section.

Claims

1. A core material for wall construction that is set into a cementitious material filled in a hole wall before the cementitious material hardens, A steel portion extending in one direction; A cuttable portion connected to one end of the steel portion; A weight portion attached to the steel material portion and extending along the one direction on at least a side of the steel material portion opposite to the cuttable portion; Equipped with Core material for wall construction.

2. The steel part has a side surface extending along the one direction, The weight portion is a steel plate-shaped member fixed to the side surface so as to extend along the side surface. The wall construction core material according to claim 1.

3. A method for constructing a wall construction core material, comprising the steps of: The wall construction core material has a steel portion extending in one direction and a cuttable portion connected to one end of the steel portion, forming a hole wall by drilling; filling the pore walls with a cementitious material; Attaching a weight portion to the steel portion; before the cement-based material hardens, a step of erecting the wall construction core material into the cement-based material with the steel part facing downward relative to the cuttable part; Equipped with How to build it:

4. In the step of forming the hole wall, the excavator is moved along an in-plane direction of the wall body while excavating with the excavator, thereby forming a hole wall that extends continuously along the in-plane direction. The method of claim 3.

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