Excavation method, bucket and excavation point restraining tool used in the same

Abstract

To provide an excavation method, a bucket, and an excavation point restraining tool capable of suppressing peeling off of a shoulder portion, which is an outer edge portion of an excavated portion, when excavating surface soil with a bucket.SOLUTION: An excavation method is a method for forming a trench 2 into which a hardened body that hardens over time to become a foundation beam 1 is poured by excavating a surface of the ground 3, and includes steps of: positioning guide rails 5 having short side ends and long side straight edges so that the long side straight edges of the guide rails 5 are aligned along the outside of planned lines to become two edges of the foundation beam 1; fixing the guide rail 5 to the surface of the ground 3; and operating a bucket 7 attached to an arm 8 of the heavy equipment to form the trench 2 with the soil between the guide rails 5, 5 on the planned lines to become the two edges.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a method of excavating a trench into which a hardened body that will become a foundation beam is poured, a bucket used in the method, and an excavation site restraint jig used in the method. [Background technology]

[0002] Patent Document 1 discloses that a trench into which concrete to become a foundation beam is poured is formed by excavating the surface of the surface-improved ground. The excavation is performed using a backhoe with a bucket attached to the end of the arm, but when the bucket is pulled to dig the soil, the shoulder portion, which is the upper edge of the rising surface of the excavated trench, may peel off in a block shape due to the pulling or lifting of the soil by the bucket, making it impossible to form the trench into a rectangular shape. Therefore, in order to separate the excavated portion from the shoulder portion, a diamond cutter is inserted on the boundary between the excavated portion and the shoulder portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 717505 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional method has the disadvantage that the construction period is long due to the time required to insert the diamond cutter on the boundary between the excavated part and the shoulder part and the time required for the surface layer to harden. In addition, it is difficult to pull the bucket horizontally with the backhoe, and careful operation of the heavy machinery is required to excavate to the designed depth, which also increases the time required for excavation. On the other hand, if the excavation is deeper than the designed depth, more concrete than necessary will be used.

[0005] In view of the above circumstances, an object of the present invention is to provide an excavation method that can prevent the shoulder portion, which is the outer edge portion of the excavated portion, from being pulled and peeled off when surface soil is excavated with a bucket, a bucket that can prevent excavation deeper than the designed depth, and an excavation site restraint jig that can contribute to preventing the above-mentioned peeling off when surface soil is excavated with a bucket. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the excavation method of the present invention is a method for forming a trench into which a hardened body that will become the foundation beam is poured by excavating the surface layer of the ground, and is characterized by including the steps of: positioning a guide rail having a short side end portion and a long side straight edge portion so that the long side straight edge portion of the guide rail is aligned along the outside of the planned lines that will become the two edges of the foundation beam; fixing the guide rail to the surface layer of the ground; and operating a bucket attached to the arm of a heavy machine to excavate the soil between the guide rails on the planned lines that will become the two edges, thereby forming a trench.

[0007] With the above method, the shoulder portion, which is the upper edge portion of the rising surface of the groove portion, is restrained from above by the guide rail, so that the shoulder portion can be prevented from peeling off when the bucket is used to excavate the surface layer.

[0008] In the above excavation method, the soil between the guide rails may be excavated after surface improvement is performed to harden the surface layer of the ground and develop a surface strength sufficient to enable the surface layer to stand on its own even after excavation. Even when surface improvement is performed in this way, the work of inserting a diamond cutter is not required, and excavation can be completed in a relatively short period of time.

[0009] In the above excavation method, the guide rail may be fixed to the surface layer of the ground by means of nail-like fastening members, which makes it possible to easily fix the guide rail to the surface layer of the ground.

[0010] The bucket of the present invention is a bucket used in the above-mentioned excavation method, and is characterized in that a protrusion that abuts on the upper surface of the guide rail is attached to the outside of both side plate portions that form the rising surface of the groove portion, at a position spaced a fixed distance from the scoop tip portion that forms the bottom surface of the groove portion.

[0011] With a bucket having the above configuration, by aligning the position of the projections spaced a certain distance apart with the designed depth of the trench to be excavated, the scoop tip forms the bottom surface at just the right depth at the position where the projections hit the upper surface of the guide rail. In other words, by excavating while the projections of the bucket attached to the tip of the arm of a heavy machine hit the upper surface of the guide rail, a trench of the designed depth can be formed, and it is possible to avoid putting in more hardened body than necessary to become the foundation beam.

[0012] In the bucket having the above configuration, the protruding portion may include a protruding rod portion protruding from the side plate portion, and a cylindrical peripheral member provided rotatably about the protruding rod portion. According to this, when the bucket is pulled while the protruding portion is in contact with the upper surface of the guide rail, the cylindrical peripheral member rolls on the upper surface of the guide rail, so that the bucket can be pulled smoothly.

[0013] In the bucket having the above configuration, the side plate portions may be provided with a plurality of mounting portions to which the protrusions are attached so that any distance can be selected as the constant distance, thereby allowing one bucket to accommodate a plurality of groove depths.

[0014] In the bucket having the above-mentioned configuration, the width of the separation between the side plates may be narrowed toward the scoop tip. This makes it possible to prevent the rear and sides of the bucket from becoming in a vacuum state and causing the upright surface to collapse when excavating clayey ground. In addition, in sandy soil, this also has the effect of preventing the excavation surface from collapsing.

[0015] The excavation site restraint jig of the present invention is an excavation site restraint jig for use in the above-mentioned excavation method, characterized in that it comprises a pair of guide rails having short side end portions and long side straight edge portions, and a spacing adjustment member having an engagement portion whose engagement width is variable for engaging with the pair of guide rails to adjust the spacing between the pair of guide rails.

[0016] With the excavation site restraint jig configured as described above, the separation width of the pair of guide rails can be easily adjusted by the spacing adjustment member to match the width of the groove at the site where the groove is excavated, into which the hardened body that will harden over time to become the foundation beam is poured, thereby making work more efficient.

[0017] In the excavation point restraint jig having the above-mentioned configuration, the guide rail may include a plate member that protrudes outward from the long side straight edge portion and contacts the ground. This makes it easy to fix the guide rail to the ground using the plate member.

[0018] In the excavation point restraint jig having the above-mentioned configuration, the two guide rails may be connected to each other at their short side ends by a joint. In this way, the guide rails can be appropriately connected to make the long side straight edge continuous to a required length. Effect of the Invention

[0019] According to the present invention, the shoulder portion, which is the upper edge portion of the rising surface of the groove portion, is restrained from above by the guide rail, thereby achieving the effect of preventing the shoulder portion from peeling off when the surface layer is excavated with a bucket. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is an explanatory diagram showing an excavation method according to an embodiment. [Diagram 2] 1 is an explanatory diagram showing a groove and a foundation beam formed by an excavation method according to an embodiment of the present invention. [Diagram 3] 1 is an explanatory diagram showing the creation of a trench and a foundation beam by an excavation method according to an embodiment of the present invention. FIG. [Figure 4] FIG. 4 is an explanatory diagram showing a protruding portion of the bucket according to the embodiment. [Diagram 5] 2A and 2B are explanatory diagrams showing the front and side of a bucket according to an embodiment. [Figure 6] 13A and 13B are explanatory views showing the front and side of a bucket according to another embodiment. [Figure 7] 2A to 2C are explanatory diagrams showing a plan view, a front view, and a side view of an excavation point restraint jig according to an embodiment. [Figure 8] 1 is an explanatory diagram showing a plan view of a guide rail to which a joint used in an excavation site restraint jig of an embodiment is attached, as well as a front view and a side view of the joint. FIG. [Figure 9] 4A and 4B are explanatory views showing a plan view and a front view of a distance adjusting member in the excavation point restraint jig of the embodiment. [Figure 10] 1 is an explanatory diagram showing the joining of guide rails by a joint used in an excavation site restraint jig of an embodiment, and the fitting of the joint to the guide rail. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] (Embodiment 1) Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. As shown in FIG. 1, in the excavation method of the embodiment, a trench 2 is formed by excavating the surface layer of the ground 3. In a later process, concrete (a hardened body that hardens over time) that will become a foundation beam 1 is poured into the trench 2 as shown in FIG. 2. In this embodiment, pile driving into the ground 3 and surface layer improvement for hardening the surface layer of the ground 3 are performed, and the soil is excavated after the surface layer has developed a strength sufficient to enable it to stand on its own even after excavation. Note that the excavation method using the guide rail 5 is also effective in an embodiment in which the above-mentioned surface layer improvement is not performed and only rolling compaction of the ground is performed.

[0022] In the excavation method of this embodiment, a pair of guide rails 5, 5 are used for one linear trench 2. Each guide rail 5 is made of a steel member 51, for example, a wide rectangular steel pipe 4 m long, with short side ends at both ends and long side straight edges at both edges. Each guide rail 5 is arranged so that the long side straight edges are along the outside of the planned lines 2L, 2L that are the two edges of the trench 2 (foundation beam 1). The planned lines 2L, 2L can be drawn from markings of the construction positions of the foundation beams 1, and the guide rails 5 are arranged taking into consideration the excavation sequence of the trench 2.

[0023] Plate members 52 made of L-angle members are fixed by welding to the side surface of the steel member 51 of each guide rail 5 at predetermined intervals. The lower plate portion of the plate member 52 protrudes to one outside of the steel member 51 (the side opposite to the side where the groove portion 2 is formed) and contacts the ground 3. A hole through which a peg (nail-like fastening member) P can be inserted is formed in the center of the lower plate portion of the plate member 52, and the peg P is driven into this hole from above to fix each guide rail 5 to the surface layer of the ground 3.

[0024] 3, the soil between the guide rails 5, 5 on the planned lines 2L, 2L which form both edges of the groove 2 (foundation beam 1) is excavated by operating a vertical excavation type bucket 7 attached to the arm 8 of the heavy machinery. In this embodiment, the bucket 7 has a protrusion 73 which abuts on the upper surface of the steel member 51 of the guide rail 5, located outside the side plate portions 71 on both sides which form the rising surface 2a of the groove 2 and at a fixed distance from the scoop tip portion 72 which forms the bottom surface 2b of the groove 2.

[0025] 4, each protruding portion 73 includes a protruding rod portion 73a protruding from the side plate portion 71 in a direction perpendicular to the surface of the side plate portion 71, and a cylindrical peripheral member 73b provided rotatably about the protruding rod portion 73a. A through hole portion 71a is formed in the side plate portion 71 as an attachment portion for attaching the protruding portion 73 to the side plate portion 71.

[0026] The protruding rod portion 73a is, for example, a bolt inserted into the through hole portion 71a with its head positioned inside the bucket 7, and a nut screwed into a threaded portion formed only on the head side of the bolt, sandwiching the side plate portion 71 between the head and the bolt. The bolt is formed into a non-threaded columnar portion with threaded unevenness cut out except for the threaded portion. On the other hand, the cylindrical peripheral member 73b is, for example, a hollow portion extending on the axis of a cylindrical metal body, and the non-threaded columnar portion of the bolt, which is the protruding rod portion 73a, is accommodated in the hollow portion. A recess is formed at the outer end of the cylindrical peripheral member 73b to accommodate the head of the fastening screw 73c, and a female screw portion is formed at the outer end of the bolt, which is the protruding rod portion 73a. When the screw portion of the fastening screw 73c is screwed into this female screw portion, the cylindrical peripheral member 73b is caught on the head of the fastening screw 73c and prevented from coming off.

[0027] With the above excavation method, the shoulder portion, which is the upper edge portion of the rising surface 2a of the trench 2, is restrained from above by the guide rail 5, so that it is possible to prevent the shoulder portion from peeling off when the surface layer is excavated with the bucket 7. By using a relatively heavy guide rail 5, it is possible to expect a restraining effect on the shoulder portion due to the weight of the guide rail 5.

[0028] In addition, the soil between the guide rails 5, 5 is excavated after surface improvement is performed to harden the surface layer of the ground 3 and develop a surface strength that allows the surface layer to stand on its own even after excavation, but even in this case, the work of inserting diamond cutters is not required and excavation can be completed in a relatively short period of time. If the time required for excavation becomes long and the surface layer strength increases, it is possible to insert diamond cutters or pour concrete into the peeled off parts.

[0029] Furthermore, since the guide rail 5 is fixed to the surface layer of the ground 3 using the pegs P, which are nail-like fastening members, the guide rail 5 can be easily fixed to the surface layer of the ground 3. Even if the plate member 52 does not have holes through which the pegs P can be passed, the guide rail 5 can be fixed to the ground 3 by, for example, arranging a pressing member that abuts against the edge of the plate member 52 and inserting a nail-like fastening member such as the pegs P into the hole of this pressing member.

[0030] In addition, the bucket 7 has a protrusion 73 that abuts on the upper surface of the guide rail 5 at a position outside the side plate parts 71 on both sides that form the rising surface 2a of the groove 2 and at a position spaced a certain distance from the scoop tip part 72 that forms the bottom surface 2b of the groove 2. Therefore, by setting the position of the protrusion 73 that is spaced a certain distance apart according to the design depth of the groove 2 to be excavated and excavating, the scoop tip part 72 forms the bottom surface 2b at just the right depth at the position where the protrusion 73 abuts on the top surface of the guide rail 5. In other words, by excavating while the protrusion 73 of the bucket 7 attached to the tip of the arm part 8 of the heavy machine abuts on the top surface of the guide rail 5, the groove 2 can be formed to the designed depth, and it is possible to avoid pouring more concrete than necessary to become the foundation beam 1. In addition, since the protrusion 73 of the bucket 7 presses the guide rail 5 from above in this way, the restraining effect on the shoulder part is improved.

[0031] In addition, the protruding portion 73 is equipped with a protruding rod portion 73a protruding from the side plate portion 71, and a cylindrical surrounding member 73b that is freely rotatable around this protruding rod portion 73a as an axis. Therefore, when pulling the bucket 7 while bringing the cylindrical surrounding member 73b of the protruding portion 73 into contact with the upper surface of the guide rail 5, the cylindrical surrounding member 73b rolls on the upper surface of the guide rail 5, so that the operation of pulling the bucket 7 can be performed smoothly.

[0032] 5, a plurality of (e.g., three) through-holes 71a, which are mounting portions to which protrusions 73 are attached, may be formed in both side plate portions 71, 71 of bucket 7 so that any distance can be selected as the above-mentioned fixed distance. This allows one bucket 7 to accommodate a variety of groove depths. Note that through-holes 71a are formed, for example, at intervals of 5 cm.

[0033] As shown in FIG. 6, the width of the gap between the two side plates 71, 71 of the bucket 7 may be tapered so as to become narrower toward the scoop tip 72. This forms a groove 2 that narrows toward the bottom, and the rising surface 2a (side wall) is inclined, so that collapse of the rising surface 2a can be suppressed. Although the amount of concrete used increases, a foundation beam 1 having an inverted trapezoidal vertical cross section (groove 2 with the bottom surface 2b narrower than the opening end width) is produced. The angle of inclination of the tapered shape is, for example, about 2 degrees to 5 degrees with respect to the vertical line. The portion where the protrusion 73 is attached may not be tapered.

[0034] As shown in Fig. 7, the excavation point restraint jig 6 of the embodiment includes a guide rail 5 having a short side end portion and a long side straight edge portion, and two space adjustment members 4 for adjusting the separation width between the two guide rails 5. The plate member 52 of the guide rail 5 is not limited to the L-angle member shown in Fig. 1, but may be a flat plate member welded to the lower side edge of a steel member 51 as shown in Fig. 7. The guide rail 5 is not limited to being composed of a steel member 51 and a plate member 52, but may be composed of a single long plate member.

[0035] As shown in Figure 9, each spacing adjustment member 4 comprises a main body 41 made of lip channel steel having a length of, for example, about 1 m, a base end engagement portion 42 fixed with a bolt to the end position on the web surface side of the main body 41, and an adjustment side engagement portion 43 fixed with a bolt to a position near the end of the web surface side of the main body 41 so that its position can be changed. The web surface of the main body 41 is abutted against the upper surface of the guide rail 5, and the hanging side piece of the L-angle member constituting the base end engagement portion 42 and spacing adjustment member 43 is abutted against the side surface of the guide rail 5 for use.

[0036] The web surface of the main body 41 on which the adjustment side engagement portion 43 is disposed has two bolt insertion holes 41a at positions with different distances from the base end side engagement portion 42. The base end side engagement portion 42 and the adjustment side engagement portion 43 are members that are abutted so as to sandwich the two guide rails 5 from the outside, and the width of the two guide rails 5, 5 is adjusted stepwise, for example, at intervals of 5 cm, by adjusting the interval (engagement width) between the base end side engagement portion 42 and the adjustment side engagement portion 43. An end position bolt insertion hole is formed at the end position of the side surface of the main body 41, and the base end side engagement portion 42 and the adjustment side engagement portion 43 after the width adjustment can be fixed to the guide rail 5 by a bolt 45 and a nut passed through the bolt insertion hole formed in the hanging side piece. By fixing the interval adjustment member 4 to the guide rail 5, the shifting movement of the guide rail 5 is reduced compared to the case where the guide rail 5 is fixed only by the peg P.

[0037] As shown in Figs. 8 and 10, two guide rails may be connected to each other at their short side ends by a joint 500. In this way, the long side straight edge portion can be made continuous to the required length by appropriately connecting a plurality of guide rails 5, 5. In this embodiment, the joint 500 is assembled using a plurality of members so as to contact two points on each of the left and right vertical surfaces and two points on each of the top and bottom horizontal surfaces inside the square steel pipe, and not to contact the four corners inside the square steel pipe. Furthermore, the two contact points on the left and right vertical surfaces inside the square steel pipe are spaced apart, so that the joint 500 can be inserted without the bolt 45 getting caught. Of course, the joint 500 is not limited to such a structure using a plurality of members, and may be constructed by using a square steel pipe that fits just inside the square steel pipe that forms the guide rail 5.

[0038] Although the embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to the illustrated embodiment. Various modifications and variations can be made to the illustrated embodiment within the same scope as the present invention or within an equivalent scope. [Explanation of symbols]

[0039] 1: Foundation beam 2: Groove 2L: Plan line 2a: Upright surface 2b: Bottom 3: Ground 4: Spacing adjustment member 5: Guide rail 6: Excavation site restraint jig 7: Bucket 8: Arm section 41: Main body 41a: Bolt insertion hole 42: Proximal side engaging part 43: Adjustment side engagement part 51: Steel parts 52: Plate member 71: Side plate part 71a: Through hole part 72:Tip 73:Protrusion 73a:Protruding rod part 73b: Cylindrical surrounding member 73c: Screw 500: Joint P: Peg (nail-like fastening member)

Claims

1. An excavation method for forming a trench into which the hardened body that will become the foundation beam is poured by excavating the surface of the ground, the excavation method comprising the steps of: positioning a guide rail having a short side end and a long side straight edge so that the long side straight edge of the guide rail is aligned along the outside of the planned lines that will become the two edges of the foundation beam; fixing the guide rail to the surface of the ground; and operating a bucket attached to the arm of a heavy machine to excavate the soil between the guide rails on the planned lines that will become the two edges, to form a trench.

2. 2. The excavation method according to claim 1, further comprising the steps of: carrying out surface improvement work to harden the surface layer of the ground; and excavating the soil between the guide rails after the surface layer has developed a strength sufficient to enable it to stand on its own even after excavation.

3. 2. The excavation method according to claim 1, wherein said guide rail is fixed to the surface layer of said ground by means of nail-like fastening members.

4. A bucket used in the excavation method according to any one of claims 1 to 3, characterized in that the bucket is provided with a protrusion that abuts on an upper surface of the guide rail, the protrusion being located on the outside of both side plate portions that form the rising surface of the groove portion and spaced a fixed distance from a scoop tip portion that forms the bottom surface of the groove portion.

5. 5. The bucket according to claim 4, wherein the protruding portion comprises a protruding rod portion protruding from each of the two side plate portions, and a cylindrical peripheral member provided rotatably about the protruding rod portion as an axis.

6. 5. The bucket according to claim 4, wherein a plurality of mounting portions to which the protrusions are attached are provided on both side plate portions so that an arbitrary distance can be selected as the fixed distance.

7. 5. The bucket according to claim 4, wherein the width between said two side plates is narrowed toward said scoop tip.

8. An excavation location restraint jig for use in the excavation method described in any one of claims 1 to 3, comprising a guide rail having a short side end portion and a long side straight edge portion, and a spacing adjustment member that adjusts the separation width between two guide rails by an engagement portion having a variable engagement width that engages with the two guide rails.

9. 9. An excavation location restraining jig according to claim 8, wherein the guide rail is provided with a plate member that protrudes outward from the linear edge portion on the long side and contacts the ground.

10. 9. The excavation location restraining jig according to claim 8, wherein the two guide rails are connected to each other at their short side ends by a joint.

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