Wall shape improvement material, soil improvement machine, and construction method of wall shape improvement material

Abstract

To provide a wall shape improvement material capable of preventing vertical cracks at joints, a soil improvement machine, and a construction method of wall shape improvement material.SOLUTION: A wall shape improvement material 40A is formed in a wall shape using an improvement material with higher strength than the ground. The wall shape improvement material has a joint surface J3 including convex and concave portions in the excavation direction in the plan view.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a wall-shaped improvement body, a ground improvement machine, and a method for constructing a wall-shaped improvement body.

Background Art

[0002] The following Patent Document 1 describes a technique for constructing a wall-shaped improved ground in a grid pattern using a trencher-type ground improvement device.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When constructing a wall-shaped improved ground (wall-shaped improvement body) as shown in the above Patent Document 1, depending on the scale of the wall-shaped improvement body, the construction work may not be completed in one day. In such a case, there is a risk that the joint surface between the previously constructed part and the subsequently constructed part across days becomes a cold joint. In such a case, when a horizontal force acts along the wall surface of the wall-shaped improvement body, vertical cracks are likely to occur at the joint surface.

[0005] In consideration of the above facts, an object of the present disclosure is to provide a wall-shaped improvement body, a ground improvement machine, and a method for constructing a wall-shaped improvement body that can suppress vertical cracks at the joint surface.

Means for Solving the Problems

[0006] The wall-shaped improvement body according to claim 1 is formed in a wall shape using an improvement material having a higher strength than the ground, and has a joint surface provided with convex portions and concave portions with respect to the excavation direction in a plan view.

[0007] In the wall-shaped improvement body of claim 1, since the joint surface has convex and concave portions with respect to the excavation direction, the area of the joint surface is larger compared to the case where the joint surface is flat with respect to the excavation direction, that is, along the wall thickness direction. Therefore, the adhesion area between the portions before and after the joint surface is large.

[0008] As a result, when a horizontal force acting along the wall surface of the wall-shaped improvement body acts during an earthquake, the portions before and after the joint surface are less likely to shift relative to each other, and vertical cracks are less likely to occur at the joint surface.

[0009] The wall-shaped improvement body of claim 2 is the wall-shaped improvement body according to claim 1, and includes a first wall-shaped body arranged along one direction, and a second wall-shaped body whose end face is in contact with the side surface of the first wall-shaped body and is arranged along a direction intersecting the first wall-shaped body. The joint surface is formed on the end face and has convex and concave portions with respect to the excavation direction of the second wall-shaped body.

[0010] In the ground improvement body of claim 2, the joint surface between the first wall-shaped body and the second wall-shaped body intersecting the first wall-shaped body has convex and concave portions with respect to the excavation direction of the second wall-shaped body.

[0011] As a result, when a horizontal force acting along the wall surface of the second wall-shaped body acts during an earthquake, the portions before and after the joint surface are less likely to shift relative to each other, and vertical cracks are less likely to occur at the joint surface.

[0012] The ground improvement machine of claim 3 includes a discharge unit that discharges an improvement material having a higher strength than the ground, an endless track wound around a plurality of idler wheels, a plurality of stirring blades arranged along the circumferential direction of the endless track, and a plurality of excavation claws respectively connected to the stirring blades, excavating the ground and stirring with the improvement material to construct a ground improvement body. The trajectories of the tips of the plurality of excavation claws accompanying the rotation of the endless track have convex and concave portions with respect to the excavation direction.

[0013] In the ground improvement machine of claim 3, the trajectories of the tips of the plurality of excavation claws accompanying the rotation of the endless track have convex and concave portions with respect to the excavation direction.

[0014] When constructing a wall-shaped ground improvement body over a period of time, for example, using such a ground improvement machine, convex portions and concave portions are formed on the joint surface between the previously constructed wall-shaped body and the subsequently constructed wall-shaped body. Therefore, compared with the case where the joint surface is flat, that is, along the wall thickness direction, the area of the joint surface is large, and the adhesion area between the portions before and after the joint surface becomes large.

[0015] As a result, when a horizontal force acting along the wall surface of the wall-shaped improvement body acts during an earthquake, it is difficult for the portions before and after the joint surface to shift, and it is difficult for vertical cracks to occur at the joint surface.

[0016] The ground improvement machine according to claim 4 is the ground improvement machine according to claim 3, wherein the stirring blade to which the excavation claw for forming the convex portion is fixed is detachably fixed to the endless track.

[0017] In the ground improvement machine according to claim 4, the stirring blade to which the excavation claw for forming the convex portion is fixed is detachably fixed to the endless track. Thereby, the resistance of the soil can be reduced during normal excavation when it is not necessary to form the convex portion.

[0018] The method for constructing a wall-shaped improvement body according to claim 5 is to excavate the wall-shaped improvement body previously constructed using the ground improvement machine according to claim 3 or 4, and form at least one of the wall-shaped improvement bodies according to claims 1 and 2.

[0019] According to the method for constructing a wall-shaped improvement body according to claim 5, convex portions and concave portions are formed on the joint surface between the previously constructed wall-shaped body and the subsequently constructed wall-shaped body. Therefore, compared with the case where the joint surface is flat, that is, along the wall thickness direction, the area of the joint surface is large, and the adhesion area between the portions before and after the joint surface becomes large.

[0020] As a result, when a horizontal force acting along the wall surface of the wall-shaped improvement body acts during an earthquake, it is difficult for the portions before and after the joint surface to shift, and it is difficult for vertical cracks to occur at the joint surface.

Advantages of the Invention

[0021] According to the present disclosure, vertical cracking at the joint surface can be suppressed.

Brief Description of the Drawings

[0022]

Figure 1

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Figure 9

Figure 10

Figure 11

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Figure 17

Embodiments for Carrying Out the Invention

[0023] Hereinafter, a wall-shaped improvement body, a ground improvement machine, and a construction method of the wall-shaped improvement body according to embodiments of the present disclosure will be described with reference to the drawings. Components indicated by the same reference numerals in each drawing mean the same components. However, unless otherwise specified in the specification, each component is not limited to one, and a plurality of them may exist.

[0024] In addition, for the components and reference numerals that are repeated in each drawing, the description may be omitted. Note that the present disclosure is not limited to the following embodiments, and within the scope of the object of the present disclosure, it is possible to omit components, replace them with different components, use a combination of one embodiment and various modifications, etc., and implement them with appropriate changes.

[0025] <Construction of Wall-like Improvement Body> Prior to the description of the wall-like improvement body, the ground improvement machine, and the construction method of the wall-like improvement body according to the embodiments of the present disclosure, an overview of the ground improvement machine 10 (see FIG. 1) and the wall-like improvement body 40 (see FIG. 2), which is a ground improvement body constructed by the ground improvement machine 10, will be described.

[0026] (Overview of Ground Improvement Machine) The ground improvement machine 10 shown in FIG. 1 includes an excavator 12 and a stirrer 14 attached to the tip of the arm of the excavator 12. The stirrer 14 is a trencher that can stir the ground G to construct a ground improvement body including the wall-like improvement body 40.

[0027] The stirrer 14 includes an endless track 14A, stirring blades 20, and excavation claws 30 (see FIGS. 5, etc.). The endless track 14A is a rotating body wound around a plurality of idler wheels 14B. The endless track 14A is formed in an oval shape with the vertical direction as the major axis direction in the excavation and stirring posture of the ground G.

[0028] A discharge part (not shown) is provided at the lower end of the endless track 14A. An improvement material with higher strength than the ground G is discharged from the discharge part. For example, an improvement material such as cement or a cement-based solidifying material kneaded into a slurry state is jetted into the ground G from the discharge part.

[0029] The stirring blades 20 are members arranged along the width direction of the endless track 14A (the front-back direction of the paper in FIG. 1), and a plurality of them are arranged along the circumferential direction of the endless track 14A. As will be described in detail later, excavation claws 30 for excavating the ground G and stirring the improvement material and the in-situ soil to construct a ground improvement body are fixed to the stirring blades 20.

[0030] (Overview of ground improvement method) The ground improvement method using the ground improvement machine 10 is a ground improvement method also called the trench - type middle - layer mixing treatment method. In this ground improvement method, first, as shown in FIGS. 1(A) and (B), while rotating the endless track 14A, the agitator 14 is penetrated into the ground G.

[0031] Then, while injecting the improvement material into the ground, the in - situ soil and the improvement material are stirred and mixed. At this time, as shown in FIG. 1(C), while the agitator 14 is penetrated into the ground G, it is stirred while traveling horizontally at a predetermined speed.

[0032] When the improved body obtained by stirring and mixing the in - situ soil and the improvement material is constructed for a desired length, as shown in FIG. 1(D), the agitator 14 is pulled out from the ground G. By running the backhoe 12 and repeating such a process while changing the direction of the backhoe 12, the wall - like improved body 40 shown in FIG. 2(A) can be constructed.

[0033] The wall - like improved body 40 is a ground improvement body formed in a lattice shape by combining wall - like improved bodies (a mixture of in - situ soil and improvement material, hereinafter referred to as "wall bodies"). The wall - like improved body 40 is constructed, for example, over several days, and at the joint surfaces formed across days, for example, joint surfaces J10 and J20 as shown in FIGS. 2(B) and (C) are formed.

[0034] In addition, the "wall - like improved body" in the present disclosure includes, in addition to the lattice - shaped ground improvement body, a frame - shaped ground improvement body and a linear ground improvement body in plan view that does not include intersecting wall bodies.

[0035] FIG. 2(B) shows an aspect in which a joint surface J10 is formed on the linear wall body 42. In this aspect, adjacent to the end surface of the previously constructed wall body 42A, the wall body 42B is constructed. The subsequently constructed wall body 42B is formed in the same straight line as the wall body 42A. In this case, the location where the agitator 14 is pulled out from the ground G when constructing the wall body 42A and the location where the agitator 14 is penetrated into the ground G when constructing the wall body 42B are arranged adjacent to each other.

[0036] In addition, FIG. 2(C) shows an aspect in which a joint surface J20 is formed between a wall-like body 42 along one direction and a wall-like body 44 along a direction intersecting the wall-like body 42. In this aspect, at the side surface of the previously constructed wall-like body 42, a place where the stirrer 14 penetrates into the ground G during the construction of the wall-like body 44 is arranged adjacent thereto, and the joint surface J20 is formed at the end surface of the wall-like body 44.

[0037] <Overview of each embodiment> In the following description, a wall-like improved body 40A having joint surfaces J1 and J2 bent in plan view (see FIG. 3), a ground improvement machine 10A for constructing the wall-like improved body 40A (see FIG. 5) and a ground improvement machine 10B (see FIG. 6), a wall-like improved body 40C having joint surfaces J1 and J2 (see FIG. 7), and a ground improvement machine 10C for constructing the wall-like improved body 40C (see FIG. 8) will be described as the first embodiment.

[0038] Also, a wall-like improved body 40D having joint surfaces J3 and J4 having convex and concave portions in plan view (see FIG. 9), a ground improvement machine 10D for constructing the wall-like improved body 40D (see FIG. 10), and a ground improvement machine 10E (see FIG. 11) will be described as the second embodiment.

[0039] Furthermore, a wall-like improved body 40F having joint surfaces J5 and J6 bent in side view (see FIG. 12), a ground improvement machine 10F for constructing the wall-like improved body 40F (see FIG. 14), a wall-like improved body 40G having joint surfaces J7 and J8 bent in side view (see FIG. 15), and a modified example of the ground improvement machine 10F for constructing the wall-like improved body 40G (see FIG. 16) will be described as the third embodiment.

[0040] <First embodiment> (Wall-like improved body) As shown in FIGS. 3(A) and (B), the wall-like improved body 40A according to the first embodiment has joint surfaces J1 and J2 bent at an angle intersecting the wall thickness direction in plan view.

[0041] The "wall thickness direction" refers to the wall thickness direction of the linear wall body 42 shown in Fig. 3(A) at the joint surface J1 between the previously constructed wall body 42A and the subsequently constructed wall body 42B.

[0042] Also, the "wall thickness direction" refers to the wall thickness direction of the subsequently constructed wall body 44 at the joint surface J2 between the wall body 42 (an example of the first wall body in the present disclosure) shown in Fig. 3(B) and the wall body 44 (an example of the second wall body in the present disclosure) orthogonal to the wall body 42.

[0043] "Bending at an angle intersecting the wall thickness direction" means that in a plan view, the joint surface J1 or J2 is formed by combining at least two line segments, and at least one line segment has an angle greater than 0° and less than 90° with respect to the wall thickness direction.

[0044] As a specific example, "bending at an angle intersecting the wall thickness direction" means that as shown in Fig. 4(A), the joint surface J1 (or the joint surface J2 shown in Fig. 3(B)) is formed by combining two line segments, and each line segment is inclined at an equal angle with respect to the wall thickness direction W1.

[0045] Also, "bending at an angle intersecting the wall thickness direction" means that as shown in Fig. 4(B), the joint surface J1 (or the joint surface J2 shown in Fig. 3(B)) is formed by combining two line segments, and each line segment is inclined at a different angle with respect to the wall thickness direction W1.

[0046] Furthermore, "bending at an angle intersecting the wall thickness direction" means that as shown in Fig. 4(C), the joint surface J1 (or the joint surface J2 shown in Fig. 3(B)) is formed by combining two line segments, one line segment is inclined with respect to the wall thickness direction W1, and the other line segment is along the wall thickness direction W1. The mode of Fig. 4(D) will be described later.

[0047] (Ground improvement machine) As shown in Fig. 5(A), the ground improvement machine 10A for constructing the wall-shaped improvement body 40A is provided with excavation claws 30A on each of a plurality of stirring blades 20A. The plurality of stirring blades 20A in Fig. 5(A) are drawn side by side in the order of being attached to the endless track 14A (see Fig. 1), but this order is not particularly limited.

[0048] Each excavation claw 30A fixed to the plurality of stirring blades 20A is fixed with a positional deviation in the width direction of the stirring blade 20A. Also, each excavation claw 30A has a different length. Specifically, the excavation claw 30A fixed closer to the central portion in the width direction of the stirring blade 20A is longer than the excavation claw 30A fixed closer to the far position.

[0049] Thereby, as shown in Fig. 5(B), the locus K1 of the tips of the plurality of excavation claws 30A accompanying the rotation of the endless track 14A bends at an angle intersecting the width direction of the stirring blade 20A (in other words, the width direction of the endless track 14A shown in Fig. 1) in a plan view.

[0050] By using this ground improvement machine 10A, the wall-shaped improvement body 40A shown in Figs. 3(A) and (B) can be constructed. The shapes of the butting surfaces J1 and J2 in a plan view substantially coincide with the shape of the locus K1.

[0051] Note that by adjusting the length of the excavation claw 30A in the ground improvement machine 10A, as shown in Figs. 4(A) to (C), the shape of the butting surface J1 (and the butting surface J2) formed by combining two line segments can be freely set.

[0052] (Function and Effect) If a wall-shaped improvement body is constructed using the ground improvement machine 10A shown in Fig. 5(A), a butting surface J1 or J2 that bends at an angle intersecting the wall thickness direction is formed in the wall-shaped improvement body. That is, the wall-shaped improvement body 40A shown in Figs. 3(A) and (B) can be constructed.

[0053] In this wall-like improvement body 40A, as shown in Fig. 3(A), in a plan view, the joint surface J1 is bent at an angle intersecting the wall thickness direction of the wall body 42. For this reason, compared with the case where the joint surface J1 is along the wall thickness direction of the wall body 42, the area of the joint surface is large. For this reason, the adhesion areas between the portions before and after the joint surface J1, that is, the previously constructed wall body 42A and the subsequently constructed wall body 42B, are large.

[0054] Thereby, when a horizontal force P acting along the wall surface of the wall body 42 acts during an earthquake, the portions before and after the joint surface J1 are difficult to shift relative to each other, and it is difficult for longitudinal cracks to occur at the joint surface J1. In other words, it is difficult for a deformation in which the end surface of the wall body 42A and the end surface of the wall body 42B are relatively displaced in the vertical direction to occur.

[0055] Similarly, in the wall-like improvement body 40A, as shown in Fig. 3(B), the joint surface J2 between the wall body 42 as the first wall body and the wall body 44 as the second wall body intersecting the wall body 42 is bent at an angle intersecting the wall thickness direction of the wall body 44. For this reason, the adhesion areas between the portions before and after the joint surface J2, that is, the previously constructed wall body 42 and the subsequently constructed wall body 44, are large.

[0056] Thereby, when a horizontal force P acting along the wall surface of the wall body 44 acts during an earthquake, the portions before and after the joint surface J2 are difficult to shift relative to each other, and it is difficult for longitudinal cracks to occur at the joint surface J2. In other words, it is difficult for a deformation in which the side surface of the wall body 42 and the end surface of the wall body 44 are relatively displaced in the vertical direction to occur.

[0057] In this way, the joint surfaces J1 and J2 of the wall-like improvement body 40A have improved load-bearing capacity against horizontal forces compared with the joint surface along the wall thickness direction. Thereby, even when the wall-like improvement body 40A is constructed across days, it is difficult for a decrease in load-bearing capacity to occur at the joint surfaces J1 and J2.

[0058] (Modification Example 1) The wall-like improvement body 40A shown in FIGS. 3(A) and (B) can also be formed using the ground improvement machine 10B shown in FIG. 6. The ground improvement machine 10B is provided with excavation claws 30B on each of a plurality of stirring blades 20B. The stirring blades 20B are depicted arranged in order of attachment to the endless track 14A (see FIG. 1), but this order is not particularly limited.

[0059] In a plan view of the stirring posture, the stirring blade 20B is bent at an angle intersecting the width direction of the endless track 14A (see FIG. 1). Specifically, the stirring blade 20B is inclined from the end in the width direction to the center in a plan view of the stirring posture, and the portion closer to the center in the width direction has a larger protruding width than the portions closer to both ends.

[0060] Here, the "protruding width" refers to the protruding width outward in the traverse direction as viewed from the stirrer 14, and in the rear side in the traverse direction of the stirrer 14, it indicates the protruding width toward the previously constructed wall-like body. The terms "protruding width" and "protrusion" in the following description are the same.

[0061] Each of the excavation claws 30B fixed to the plurality of stirring blades 20B is fixed with a displacement in the width direction of the stirring blade 20B. The lengths of the excavation claws 30B are equal to each other.

[0062] If a wall-like improvement body is constructed using this ground improvement machine 10B, a joint surface J1 or J2 bent at an angle intersecting the wall thickness direction is formed in the wall-like improvement body. That is, the wall-like improvement body 40A shown in FIGS. 3(A) and (B) can be constructed.

[0063] Note that by adjusting the shape of the stirring blade 20B in the ground improvement machine 10B, as shown in FIGS. 4(A) to (C), the shape of the joint surface J1 (and the joint surface J2) formed by combining two line segments can be freely set.

[0064] (Modification 2) In the above embodiment, as shown in FIGS. 4(A) to 4(C), an example in which the splicing surfaces J1 and J2 are formed by combining two line segments has been described, but the embodiments of the present disclosure are not limited to this.

[0065] For example, as shown in FIG. 4(D), the splicing surface J1 (and the splicing surface J2) may be formed by combining three line segments. In this example, two line segments are inclined with respect to the wall thickness direction W1, and the line segment sandwiched between the inclined line segments is along the wall thickness direction W1. According to such an aspect, the wall-like improvement body 40C shown in FIGS. 7(A) and 7(B) is constructed.

[0066] The wall-like improvement body 40C shown in FIGS. 7(A) and 7(B) can be formed using the ground improvement machine 10C shown in FIG. 8. The ground improvement machine 10C is provided with excavation claws 30C on each of a plurality of stirring blades 20C. The stirring blades 20C are depicted arranged in order of being attached to the endless track 14A (see FIG. 1), but this order is not particularly limited.

[0067] The stirring blade 20C has a portion bent at an angle intersecting the width direction of the endless track 14A (see FIG. 1) in a plan view of the stirring posture. Specifically, both ends of the stirring blade 20C are inclined from the end in the width direction to the central portion in a plan view of the stirring posture. On the other hand, the central portion of the stirring blade 20C is along the width direction of the endless track 14A (see FIG. 1). Also, the central portion of the stirring blade 20C has a larger protruding width compared to both ends.

[0068] Each excavation claw 30C fixed to the plurality of stirring blades 20C is fixed with a displacement in the width direction of the stirring blade 20C. Also, the lengths of these excavation claws 30C are equal to each other.

[0069] In this way, since the central portion of the stirring blade 20C is along the width direction of the endless track 14A (see FIG. 1), compared with the ground improvement machine 10A shown in FIG. 5 and the ground improvement machine 10B shown in FIG. 6, the bending angle of the excavation surface becomes gentle.

[0070] Therefore, it is easy for the improved body obtained by stirring and mixing the in-situ soil and the improvement material to enter the excavation surfaces forming the joint surfaces J1 and J2. As a result, it is difficult for junk to occur on the joint surfaces J1 and J2.

[0071] (Other Modification Examples) As shown in FIGS. 3 and 7, the wall-shaped improved bodies 40A and 40C in the present embodiment are inclined such that the central portion in the width direction of the wall-shaped body 42 on the joint surface J1 protrudes (convex toward the previously constructed wall-shaped body 42A), but the embodiment of the present disclosure is not limited to this.

[0072] Although illustration is omitted, for example, it may be inclined such that both end portions in the width direction of the joint surface J1 protrude (the central portion in the width direction is convex toward the subsequently constructed wall-shaped body 42B).

[0073] Similarly, it may be inclined such that both end portions in the width direction of the joint surface J2 protrude (the central portion in the width direction is convex toward the subsequently constructed wall-shaped body 44).

[0074] In this case, in the ground improvement machine 10A, the length of the excavation claw 30A fixed at a position closer to the central portion in the width direction of the stirring blade 20A is made shorter than that of the excavation claw 30A fixed at a distant position.

[0075] Also, in the ground improvement machine 10B, the protruding width of the central portion in the width direction of the stirring blade 20B is made smaller than that of both end portions.

[0076] Also, in the ground improvement machine 10C, the protruding width of the central portion in the width direction of the stirring blade 20C is made smaller than that of both end portions.

[0077] <Second Embodiment> (Wall-shaped Improved Body) As shown in FIGS. 9(A) and 9(B), the wall-shaped improved body 40D according to the second embodiment has joint surfaces J3 and J4 having convex portions and concave portions with respect to the excavation direction in a plan view.

[0078] The "excavation direction" is the in-plane direction of the linear wall-like body 42 shown in Fig. 9(A) at the joint surface J3 between the previously constructed wall-like body 42A and the subsequently constructed wall-like body 42B.

[0079] Also, the "excavation direction" is the in-plane direction of the subsequently constructed wall-like body 44 at the joint surface J4 between the wall-like body 42 shown in Fig. 9(B) and the wall-like body 44 orthogonal to the wall-like body 42.

[0080] "Provided with convex and concave portions with respect to the excavation direction" means, in plan view, a mode having a portion (convex portion) protruding in the excavation direction. The concave portion refers to the portion other than the convex portion and is a portion recessed relative to the convex portion.

[0081] At the joint surface J3, the central portion in the width direction of the wall-like body 42 is the convex portion, and both sides of the convex portion are the concave portions. Similarly, at the joint surface J4, the central portion in the width direction of the wall-like body 44 is the convex portion, and both sides of the convex portion are the concave portions.

[0082] Note that "protruding in the excavation direction" here is, as in the first embodiment, the protruding width outward in the lateral direction as viewed from the agitator 14, and on the rear side in the lateral direction of the agitator 14, it indicates the protruding width toward the previously constructed wall-like body side.

[0083] (Ground improvement machine) The ground improvement machine 10D for constructing the wall-like improvement body 40D is provided with excavation claws 30D on each of a plurality of stirring blades 20D as shown in Fig. 10. The plurality of stirring blades 20D in Fig. 10 are drawn arranged in the order attached to the endless track 14A (see Fig. 1), but this order is not particularly limited.

[0084] Each excavation claw 30D fixed to the plurality of stirring blades 20D is fixed with a displacement in the width direction of the stirring blade 20D. Each excavation claw 30D is formed in two types of lengths. Specifically, the excavation claw 30D fixed to the central portion in the width direction of the stirring blade 20D is longer than the excavation claw 30D fixed at a distant position.

[0085] As a result, the locus K2 of the tips of the plurality of excavation claws 30D accompanying the rotation of the infinite track 14A is formed with convex and concave portions with respect to the excavation direction in plan view.

[0086] By using this ground improvement machine 10D, the wall-like improvement body 40D shown in FIGS. 9(A) and (B) can be constructed. The shapes of the joint surfaces J3 and J4 in plan view substantially coincide with the shape of the locus K2.

[0087] (Function and Effect) If a wall-like improvement body is constructed using the ground improvement machine 10D shown in FIG. 10, a joint surface J3 or J4 having convex and concave portions with respect to the excavation direction is formed in the wall-like improvement body. That is, the wall-like improvement body 40D shown in FIGS. 9(A) and (B) can be constructed.

[0088] In this wall-like improvement body 40D, in plan view, the joint surface J3 has convex and concave portions with respect to the excavation direction. For this reason, the area of the joint surface is larger compared to the case where the joint surface is flat with respect to the excavation direction, that is, there is only a portion along the wall thickness direction of the wall body 42.

[0089] For this reason, the adhesion area between the portions before and after the joint surface J3, that is, between the previously constructed wall body 42A and the subsequently constructed wall body 42B, is large.

[0090] As a result, when a horizontal force P acting along the wall surface of the wall body 42 acts during an earthquake, the portions before and after the joint surface J3 are difficult to shift relative to each other, and vertical cracks are less likely to occur at the joint surface J3. In other words, deformation in which the end surface of the wall body 42A and the end surface of the wall body 42B are relatively displaced in the vertical direction is less likely to occur.

[0091] Similarly, in the wall-like improvement body 40D, as shown in FIG. 9(B), the joint surface J4 between the wall body 42 as the first wall body and the wall body 44 as the second wall body intersecting the wall body 42 has convex and concave portions with respect to the excavation direction.

[0092] Therefore, the area of the joint surface is larger compared to the case where the joint surface is flat with respect to the excavation direction, that is, there is only a portion along the wall thickness direction of the wall-like body 44.

[0093] As a result, when a horizontal force P acts along the wall surface of the wall-like body 44 during an earthquake, it is difficult for the portions before and after the joint surface J4 to shift relative to each other, and it is difficult for longitudinal cracks to occur at the joint surface J4. In other words, it is difficult for a deformation to occur in which the side surface of the wall-like body 42 and the end surface of the wall-like body 44 are displaced relative to each other in the vertical direction.

[0094] Thus, the joint surface J3 or J4 of the wall-like improvement body 40D has improved load-bearing capacity against horizontal forces compared to a joint surface that only has a portion along the wall thickness direction. As a result, even if the wall-like improvement body 40D is constructed across days, it is difficult for a decrease in load-bearing capacity to occur at the joint surface J3 or J4.

[0095] (Modification Example 1) The wall-like improvement body 40D shown in FIGS. 9(A) and 9(B) can also be formed using the ground improvement machine 10E shown in FIG. 11. The ground improvement machine 10E is provided with excavation claws 30E1 on each of a plurality of stirring blades 20E1. Further, the ground improvement machine 10E is provided with excavation claws 30E2 on each of a plurality of stirring blades 20E2. The stirring blades 20E1 and 20E2 are arranged side by side alternately. Although the stirring blades 20E1 and 20E2 are drawn side by side in the order in which they are attached to the endless track 14A (see FIG. 1), this order is not particularly limited.

[0096] Each excavation claw 30E1 fixed to the plurality of stirring blades 20E1 is fixed with a displacement in the width direction of the stirring blade 20E1. Similarly, each excavation claw 30E2 fixed to the plurality of stirring blades 20E2 is fixed with a displacement in the width direction of the stirring blade 20E2.

[0097] The excavation claws 30E1 and 30E2 have different lengths from each other. Specifically, the excavation claw 30E1 fixed to the stirring blade 20E1 is longer than the excavation claw 30E2 fixed to the stirring blade 20E2. Further, the excavation claw 30E1 is arranged closer to the center than the excavation claw 30E2 with respect to the width direction of the endless track 14A (see FIG. 1). That is, the excavation claw 30E1 forms a convex portion of the joint surface J3 or J4.

[0098] Thereby, the locus K3 of the tips of the plurality of excavation claws 30E1 and 30E2 accompanying the rotation of the endless track 14A is formed with convex and concave portions with respect to the excavation direction in plan view.

[0099] By using this ground improvement machine 10E, the wall-like improvement body 40D shown in FIGS. 9(A) and 9(B) can also be constructed. The shapes of the joint surfaces J3 and J4 in plan view substantially coincide with the shape of the locus K3.

[0100] Note that the excavation claw 30E1 to which the excavation claw 30E1 forming the convex portion of the joint surface J3 or J4 is fixed is detachably fixed to the endless track 14A. Thereby, if the excavation claw 30E1 is removed during normal excavation when it is not necessary to form a convex portion, the resistance of the soil can be reduced.

[0101] (Other Modifications) As shown in FIG. 9, the wall-like improvement body 40D in the present embodiment is formed such that the central portion in the width direction of the joint surface J3 protrudes (convex toward the previously constructed wall body 42A). However, the embodiment of the present disclosure is not limited to this.

[0102] For example, it may be formed such that both end portions in the width direction of the joint surface J3 protrude (the central portion in the width direction is convex toward the subsequently constructed wall body 42B). Similarly, it may be formed such that both end portions in the width direction of the joint surface J4 protrude (the central portion in the width direction is convex toward the subsequently constructed wall body 44).

[0103] In this case, in the ground improvement machine 10D, the length of the excavation claw 30D fixed at a position closer to the center in the width direction of the stirring blade 20D is made shorter than that of the excavation claw 30D fixed at a farther position.

[0104] Further, in the ground improvement machine 10E, the length of the excavation claw 30E1 fixed to the stirring blade 20E1 is made shorter than that of the excavation claw 30E2 fixed to the stirring blade 20E2. Also, in such a case, the stirring blade 20E2 is detachably fixed to the endless track 14A.

[0105] <Third Embodiment> (Wall-like improved body) As shown in FIGS. 12(A) and (B), the wall-like improved body 40F according to the third embodiment has butting surfaces J5 and J6 that are bent at an angle intersecting the vertical direction in a side view.

[0106] "Bent at an angle intersecting the vertical direction" means that in a side view, the butting surface J5 or J6 is formed by combining at least two line segments, and at least one line segment has an angle greater than 0° and less than 90° with respect to the vertical direction.

[0107] As a specific example, "bent at an angle intersecting the vertical direction" means that as shown in FIG. 13(A), the butting surface J5 (or the butting surface J6 shown in FIG. 12(B)) is formed by combining two line segments, and each line segment is inclined at an equal angle with respect to the vertical direction H1.

[0108] Also, "bent at an angle intersecting the vertical direction" means that as shown in FIG. 13(B), the butting surface J5 (or the butting surface J6 shown in FIG. 12(B)) is formed by combining two line segments, and each line segment is inclined at a different angle with respect to the vertical direction H1.

[0109] In these examples, the central portion of the butting surface J5 (or the butting surface J6 shown in FIG. 12(B)) in the vertical direction protrudes more than both ends (is convex toward the previously constructed wall-like body 42A).

[0110] (Ground improvement machine) As shown in Fig. 14(A), the ground improvement machine 10F for constructing the wall-shaped improvement body 40F is provided with excavation claws 30F on each of a plurality of stirring blades 20F. Each excavation claw 30F fixed to the plurality of stirring blades 20F is fixed with a displacement in the width direction of the stirring blade 20F. Each excavation claw 30F has the same length.

[0111] As shown in Fig. 14(B), the ground improvement machine 10F is provided with a central wheel 14C that projects the central portion in the vertical direction of the endless track 14A in the stirring posture along the excavation direction. The central wheel 14C is attached so as to project to the rear side in the lateral direction of the stirrer 14. For this reason, the central portion in the vertical direction of the endless track 14A projects to the rear side in the lateral direction of the stirrer 14.

[0112] As a result, the locus K4 of the tips of the plurality of excavation claws 30F accompanying the rotation of the endless track 14A bends at an angle intersecting the vertical direction in a side view.

[0113] By using this ground improvement machine 10F, the wall-shaped improvement body 40F shown in Figs. 12(A) and (B) can be constructed.

[0114] That is, if the end face of the previously constructed wall body 42A is excavated using the ground improvement machine 10F, a wall-shaped improvement body 40F having a joint surface J5 can be constructed. Further, if the side surface of the previously constructed wall body 42 is excavated using the ground improvement machine 10F, a wall-shaped improvement body 40F having a joint surface J6 can be constructed. The shapes of the joint surfaces J5 and J6 in a side view substantially coincide with the shape of the locus K4.

[0115] Note that by adjusting the protruding height and the vertical position of the central wheel 14C in the ground improvement machine 10F, as shown in Figs. 13(A) and (B), the shape of the joint surface J5 (and the joint surface J6) formed by combining two line segments can be freely set.

[0116] (Function and effect) If a wall-like improved body is constructed using the ground improvement machine 10F shown in FIGS. 14(A) and (B), a joint surface J5 or J6 that bends at an angle intersecting the vertical direction is formed in the wall-like improved body. That is, the wall-like improved body 40F shown in FIGS. 12(A) and (B) can be constructed.

[0117] In this wall-like improved body 40F, as shown in FIG. 12(A), in a side view, the joint surface J5 bends at an angle intersecting the vertical direction. For this reason, the area of the joint surface is larger compared to the case where the joint surface J5 is along the vertical direction. For this reason, the adhesion area between the portions before and after the joint surface J5, that is, the previously constructed wall-like body 42A and the subsequently constructed wall-like body 42B, is large.

[0118] Thereby, when a horizontal force P acting along the wall surface of the wall-like body 42 acts during an earthquake, the portions before and after the joint surface J5 are difficult to shift, and it becomes difficult for a vertical crack to occur at the joint surface J5. In other words, it becomes difficult for a deformation in which the end surface of the wall-like body 42A and the end surface of the wall-like body 42B are relatively displaced in the vertical direction to occur.

[0119] Similarly, in the wall-like improved body 40F, as shown in FIG. 12(B), the joint surface J6 between the wall-like body 42 as the first wall-like body and the wall-like body 44 as the second wall-like body intersecting the wall-like body 42 bends at an angle intersecting the vertical direction. For this reason, the adhesion area between the portions before and after the joint surface J6, that is, the previously constructed wall-like body 42 and the subsequently constructed wall-like body 44, is large.

[0120] Thereby, when a horizontal force P acting along the wall surface of the wall-like body 44 acts during an earthquake, the portions before and after the joint surface J6 are difficult to shift, and it becomes difficult for a vertical crack to occur at the joint surface J6. In other words, it becomes difficult for a deformation in which the side surface of the wall-like body 42 and the end surface of the wall-like body 44 are relatively displaced in the vertical direction to occur.

[0121] Thus, the joint surface J5 or J6 of the wall-like improved body 40F has improved resistance to horizontal forces compared to a joint surface along the vertical direction. Thereby, even if the wall-like improved body 40A is constructed over days, a decrease in the bearing capacity at the joint surface J5 or J6 is unlikely to occur.

[0122] (Modification example) As shown in FIG. 12, the wall-like improvement body 40F in the present embodiment is inclined such that the central portion in the vertical direction of the joint surface J5 protrudes (convex toward the previously constructed wall-like body 42A), but the embodiment of the present disclosure is not limited to this.

[0123] For example, like the joint surface J7 of the wall-like improvement body 40G in FIG. 15(A), the joint surface may be inclined such that both end portions in the vertical direction protrude (the central portion in the vertical direction is convex toward the subsequently constructed wall-like body 42B).

[0124] Similarly, like the joint surface J8 shown in FIG. 15(B), the joint surface may be inclined such that both end portions in the vertical direction protrude (the central portion in the vertical direction is convex toward the subsequently constructed wall-like body 44).

[0125] When constructing the joint surface J7 in such a manner, in the ground improvement machine 10F shown in FIG. 14, the central wheel 14C can be omitted. Then, as shown in FIGS. 16(A) and (B), by changing the angle of the endless track 14A with respect to the vertical direction, the end surface of the previously constructed wall-like body 42A is excavated to form the joint surface J7. The same applies to the joint surface J8.

[0126] Thus, "bending at an angle intersecting the vertical direction" in the present disclosure includes an aspect in which both end portions in the vertical direction of the joint surface, like the joint surface J7 shown in FIG. 15(A) (or the joint surface J8 shown in FIG. 15(B)), protrude more than the central portion (the central portion in the vertical direction is convex toward the subsequently constructed wall-like body 42B).

[0127] Further, by using the ground improvement machine 10F with the central wheel 14C omitted, for example, as shown in FIG. 17(A), the joint surface J7 (or the joint surface J8 shown in FIG. 15(B)) can be formed by combining two line segments, one line segment being inclined with respect to the vertical direction H1 and the other line segment being along the vertical direction H1.

[0128] Moreover, by using the ground improvement machine 10F with the central wheel 14C omitted, for example, as shown in FIG. 17(B), the joint surface J7 (or the joint surface J8 shown in FIG. 15(B)) can also be formed by combining three line segments. In this example, two line segments are inclined with respect to the vertical direction H1, and the line segment sandwiched between the inclined line segments is along the vertical direction H1.

[0129] <Combinations of various embodiments> In the wall-shaped improvement body 40 shown in FIG. 2(A), joint surfaces may occur at multiple locations. In such a case, the joint surfaces J1 to J8 may be selectively used for each location. That is, the ground improvement machines 10A to 10F can be freely used to form one wall-shaped improvement body 40.

[0130] Moreover, these joint surfaces J1 to J8 can also be used in combination as much as possible. For example, the joint surfaces J1 to J4 and the joint surfaces J5 to J8 can be used in combination.

[0131] For example, by combining the joint surface J1 (see FIG. 3) and the joint surface J5 (see FIG. 12), a joint surface that is bent in plan view and bent in side view can be formed. To form such a joint surface, the central wheel 14C in the ground improvement machine 10F may be combined with the ground improvement machine 10A (see FIG. 5). Combinations of the joint surfaces J2 to J4 and the joint surface J5 or J6 can be implemented in the same manner.

[0132] Moreover, by combining the joint surface J1 (see FIG. 3) and the joint surface J7 (see FIG. 15), a joint surface that is bent in plan view and bent in side view can be formed. To form such a joint surface, the previously constructed wall-shaped body may be excavated by the construction method shown in FIG. 16 using the ground improvement machine 10A (see FIG. 5). Combinations of the joint surfaces J2 to J4 and the joint surface J7 or J8 can be implemented in the same manner.

[0133] In the first embodiment, the wall-like improvement body 40A having the joint surfaces J1 and J2 bent in plan view has been described. However, either one of the joint surfaces J1 and J2 may be replaced with a joint surface that is not bent in plan view. For example, the joint surface J3, J5, or J7 may be used instead of the joint surface J1, or the joint surface J4, J6, or J8 may be used instead of the joint surface J2.

[0134] Similarly, in the second embodiment, the wall-like improvement body 40D having the joint surfaces J3 and J4 with convex and concave portions in plan view has been described. However, either one of the joint surfaces J3 and J4 may be replaced with a joint surface that does not have convex and concave portions.

[0135] For example, the joint surface J1, J5, or J7 may be used instead of the joint surface J3, or the joint surface J2, J6, or J8 may be used instead of the joint surface J4.

[0136] Similarly, in the third embodiment, the wall-like improvement body 40F having the joint surfaces J5 and J6 bent in side view, or 40G having the joint surfaces J7 and J8 has been described. However, either one of the joint surfaces J5 and J6, and either one of the joint surfaces J7 and J8 may be replaced with a joint surface that is not bent in side view.

[0137] For example, the joint surface J1, J3, or J7 may be used instead of the joint surface J5, or the joint surface J2, J4, or J8 may be used instead of the joint surface J6. Also, for example, the joint surface J1, J3, or J5 may be used instead of the joint surface J7, or the joint surface J2, J4, or J6 may be used instead of the joint surface J8. Thus, the present disclosure can be implemented in various modes.

Explanation of Reference Numerals

[0138] 10 Ground improvement machine 10A Ground improvement machine 10B Ground improvement machine 10C Ground improvement machine 14A Infinite track 14B Rollover wheel 20 Stirring blade 20A Stirring blade 20B Stirring blade 20C Stirring blade 30 Excavation claw 30A Excavation claw 30B Excavation claw 30C Excavation claw 40 Wall-like improvement body 40A Wall-like improvement body 40C Wall-like improvement body J1 Butt joint surface J2 Butt joint surface K1 Locus

Claims

1. It is formed in a wall shape using an improvement material with higher strength than the ground, In plan view, it has a joint surface with convex and concave portions with respect to the excavation direction, Wall-shaped improvement body.

2. A first wall-shaped body arranged along one direction, A second wall-shaped body whose end face is in contact with the side face of the first wall-shaped body and is arranged along a direction intersecting the first wall-shaped body, Comprising, The joint surface is formed on the end face and has convex and concave portions with respect to the excavation direction of the second wall-shaped body. The wall-shaped improvement body according to Claim 1.

3. A discharge part that discharges an improvement material with higher strength than the ground, An endless track wound around a plurality of idler wheels, A plurality of stirring blades arranged along the circumferential direction of the endless track, A plurality of excavation claws respectively connected to the stirring blades, excavating the ground and stirring with the improvement material to construct a ground improvement body, Comprising, The trajectories of the tips of the plurality of excavation claws accompanying the rotation of the endless track have convex and concave portions with respect to the excavation direction, Ground improvement machine.

4. The stirring blade to which the excavation claw forming the convex portion is fixed is detachably fixed to the endless track. The ground improvement machine according to Claim 3.

5. Excavating a wall-shaped improvement body previously constructed using the ground improvement machine according to Claim 3 or 4, and forming at least one wall-shaped improvement body of Claims 1 and 2. Construction method of wall-shaped improvement body.

Images