JP5516531B2 - Ground improvement excavator - Google Patents

Description

  The present invention is for ground improvement used in a deep ground improvement method in which a columnar improvement body is constructed by excavating a drilling hole in the ground, adding an improvement material into the drilling hole, mixing and stirring, and compacting. The present invention relates to a drilling device.

  Conventionally, as one of the deep ground improvement methods, after excavating a drill hole in the ground with a screw shaft rotated in the forward direction, an improved material mixed with excavated soil, sand, and cement-based solidified material is put into this drill hole Then, the improvement material thrown into the excavation hole is stirred by the rotor blade provided on the screw shaft, and compressed into the downward direction or the radial direction by the screw shaft rotated in the reverse direction to be consolidated, thereby constructing the columnar improvement body. The construction method is known.

  As a screw shaft used for such a construction method, it is a screw shaft for excavating a hole in soft ground, provided with a spiral blade on the outer peripheral surface of the rotating shaft, and on the outer peripheral surface of the tapered portion provided at the tip of the rotating shaft. And a plurality of rotor blades for compressing the improved material introduced into the hole during the reverse rotation of the rotary shaft in a downward direction and a radial direction, each of the rotary blades having a phase in a rotational direction of the screw shaft. Provided at different positions and at different positions in the axial direction of the screw shaft, the rotating blades of the screw shaft in order to impart radial compression to the improvement material in the hole during the reverse rotation of the screw shaft. When the screw shaft is reversely rotated, a radial component force imparting portion inclined with respect to the radial direction is provided, and in order to apply downward compression to the improvement material in the hole during the reverse rotation of the screw shaft. Downward component force imparting unit upper end than the lower side is inclined so as to precede the reverse rotational direction of the rotor blades which are provided on a lower end of the rotor blade (e.g. Patent Document 1) has been proposed.

Japanese Patent No. 4195707

  According to the screw shaft proposed in Patent Document 1, the rotor blade provided on the outer peripheral surface of the taper portion includes a radial component force applying portion inclined with respect to the radial direction of the screw shaft, and a rotor blade at the time of reverse rotation. By providing the lower component force application part inclined so that the upper end side precedes the reverse rotation direction rather than the lower side, it is possible to consolidate the improved body, so on the peripheral surface of the improved body about to sink The acting friction force is increased, and the outer peripheral surface of the improved body is provided with a concavo-convex portion, so that the improved body hardly sinks against the ground, and the structure can be directly supported by the improved body itself.

  However, the screw shaft proposed in Patent Document 1 is considered for consolidation of the improved material, but is not considered for mixing and stirring the improved material. When stirring, it takes time, and in some cases, mixing failure may occur. Further, in the conventional screw shaft, even if the excavation force is increased, the excavated soil cannot be efficiently transferred to the spiral blade, so that it still takes time to work and the construction period cannot be shortened. .

  Therefore, in view of the above-described problems, the present invention provides a ground improvement excavating apparatus that can efficiently perform excavation, agitation, and transfer of excavated soil, and can build a high-quality improved body in a short period of time. The purpose is to provide.

The invention according to claim 1 is a rotating rod provided with a spiral wing, a pair of lower wings provided below the rotating rod, an axially lower side of the rotating rod with respect to the spiral wing, and the lower wing A pair of left and right symmetrical upper wings provided on the upper side in the axial direction of the rotating rod, and the lower wing provided with a bent portion having a lower end portion and a side end portion inclined on one side in the rotational direction. The lower wing of the lower wing is inclined downwardly toward the outer side from the tapered portion of the rotating rod, and the upper wing is provided so that the upper end and the lower end are parallel to each other in plan view. It is characterized by that.

The invention according to claim 2 is characterized in that the upper wing has the same diameter in the horizontal direction as that of the spiral wing, and is inclined in a spiral manner up and down in the axial direction of the rotating rod.

According to a third aspect of the present invention, the upper wing is formed on a circumferential surface of the rotating rod so that one upper wing and the other upper wing overlap vertically in the axial direction of the rotating rod. It is characterized by that.

  According to the configuration of claim 1, by providing the lower wing and the upper wing, excavation force, agitation force, and push-up force are enhanced, excavation of the excavation hole, transfer of excavation soil, agitation of the improvement material, and Consolidation of the improved material by compaction is performed efficiently, so the construction period can be shortened and a high-quality improved body can be built to consolidate the improved material that has been sufficiently mixed and stirred to the ground. it can.

Further, according to the configuration of claim 1 , the excavation force in the vertical and horizontal directions can be increased during excavation, and the consolidation force in the vertical and horizontal directions can be increased during the construction of the improved body, the compressive strength is substantially uniform, and the outer diameter is large. Improved bodies can be built.

Moreover, according to the structure of Claim 2 , the pushing-up force of excavation soil can be heightened and the transfer path which transfers excavation soil smoothly from a lower wing to a spiral wing or a spiral wing to a lower wing can be formed.

Moreover, according to the structure of Claim 3 , the excavation force and stirring force of a vertical and horizontal direction can be improved at the time of excavation, and the proof stress of an upper wing | blade can be reinforced. Further, the excavated soil can be smoothly transferred from the lower wing to the spiral wing or from the spiral wing to the lower wing.

It is a front view at the time of the normal rotation of the excavation apparatus for ground improvement which shows Example 1 of this invention. It is a front view at the time of reverse rotation of the excavation apparatus for ground improvement same as the above. It is a side view of a lower wing same as the above. It is a top view of a lower wing | blade same as the above. It is a top view of an upper wing | blade same as the above.

  Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below do not limit the contents of the present invention described in the claims.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  First, the ground improvement construction method using the ground improvement excavation apparatus 1 of the present invention will be briefly described. The ground improvement excavation apparatus 1 of the present invention is mainly used in the dry type deep ground improvement construction method, and is applied to the construction ground. Drilling a columnar drilling hole, producing an improved material that mixes the discharged excavated soil and cement-based solidified material, throwing this improved material into the drilling hole and compacting it vertically and horizontally, improving the columnar shape It builds the body.

  Next, the structure in the ground improvement excavation apparatus 1 of this invention is demonstrated along FIGS.

  As shown in FIG. 1, a rotating rod 2 that is supported so as to be moved up and down and rotated by a building pillar (not shown), a spiral blade 3 that is provided in a spiral shape from the upper peripheral surface of the rotating rod 2, and a rotating rod A pair of lower wings 4, 4 provided at a lower portion of the circumferential surface of 2, and a pair on the lower side in the axial direction of the rotating rod 2 than the spiral wing 3, It is provided with symmetrical upper wings 5 and 5 provided. The rotating rod 2 has a tapered portion 6 that is inclined downward, and the spiral blade 3 is provided above the upper end of the tapered portion 6.

The spiral blade 3 is provided in a spiral shape in the vertical direction, which is the axial direction of the rotating rod 2, and the interval H1, H2 between the upper and lower spiral blades 3, 3 is shortened from the upper side to the lower side (H1> H2). Is provided.

  As described above, the spiral blade 3 has a configuration in which the interval between the spiral blades 3 and 3 is shortened from the upper side to the lower side, so that the surplus space is expanded as the excavated soil is transferred from the lower side to the upper side. It can be transferred smoothly. Further, as the improving material is transferred from the upper side to the lower side, the surplus space is narrowed and the transferred improving material can be consolidated.

The lower wing 4 is provided on the lower peripheral surface of the tapered portion 6 of the rotating rod 2 and is formed of a plate-like member. Further, the lower end portion 7 of the lower wing 4 is provided so as to be slightly inclined downward from the tapered portion 6 connected to the rotating rod 2 to the corner portion 8. Further, the lower wing 4 is provided on the left and right with respect to the vertical direction of the rotating rod 2, and the lower wings 4, 4 provided in a pair form an angle of approximately 45 degrees between the lower end portions 7, 7 and the side end portions 9, 9. Are provided with bent portions 10, 10A made of flat surfaces that are inclined so as to be in the same direction in the rotation direction, that is, in the circumferential direction (in the present embodiment, the positive rotation direction). Further, the bent portion 10 with the lower end portion 7 inclined and the bent portion 10A with the side end portion 9 inclined are connected with an inclination at the same angle by welding on the diagonal line 8K of the corner portion 8. Is done. In addition, the bending parts 10 and 10 which inclined the lower end part 7 make the full length X1 of the bending part 10 out of the full length X which is the height from the upper end to the lower end of the lower wing 4 perpendicular to the horizontal direction. In order to increase excavation force and push-up force, it is desirable that the flat plate portions 13 and 13 are formed so that the total length X2 of the flat plate portions 13 and 13 is approximately 1/3 or more and 1 / 1.5 or less. Further, the bent portions 10A and 10A, in which the side end portion 9 is inclined, are the full length Y1 between the pair of left and right flat plate portions 13 and 13 among the full length Y that is the full width of the pair of left and right lower wings 4 and 4. Is preferably about 1/2 or more and 3/4 or less from the viewpoint of increasing excavation force and push-up force.

  The bent portions 10 and 10A having such a configuration act as excavating blades for breaking the soil during excavation when the rotating rod 2 rotates forward, and were introduced from the ground when constructing an improved body in which the rotating rod 2 rotates in reverse. It acts as a consolidation part that compacts the improvement material to the lower side and the side of the ground. In the present embodiment, the bent portions 10 and 10A are provided at an angle of approximately 45 degrees, but are appropriately adjusted between approximately 30 degrees and approximately 60 degrees.

As described above, the lower wing 4 has a configuration in which the lower end portion 7 is inclined from the tapered portion 6 to the corner portion 8 and the bent portions 10 and 10A are formed at the lower end portion 7 and the side end portion 9. The excavation force during excavation is enhanced, and the excavated soil is collected by the bent portions 10 and 10A and pushed up to the upper wing 5 so that the excavated soil can be smoothly transferred. Further, since the bent portions 10 and 10A are formed of a flat surface that is inclined straight, the excavated soil can be gathered on the flat plate portion 13 side without accumulating, and the excavated soil can be smoothly transferred to the upper wings 5 and 5. .

  The upper blade 5 is provided on the upper peripheral surface of the tapered portion 6 of the rotating rod 2 and is a spiral plate-like member having a diameter larger than the diameter of the tapered portion 6 and the same diameter as the spiral blade 3. It is formed by. Since the upper wings 5 are provided in a pair and are bilaterally symmetric, the upper wings 5 are arranged in an X shape in a front view, and have an inclined surface 11 inclined in the same direction in the circumferential direction. The inclined surface 11 is provided steeper than the inclination of the spiral blade 3. The paired symmetrical upper and lower wings 5 and 5 are provided so that one upper wing 5 and the other upper wing 5 overlap each other in a plan view. It is formed over the above. Further, the upper wing 5 is formed in a spiral shape, but the upper end portion 14 and the lower end portion 15 are not formed radially in a plan view, but are provided so as to be substantially parallel to the horizontal direction. Furthermore, the lower wing 4 is provided so that one upper wing 5 and the other upper wing 5 overlap each other in plan view. Note that the interval T1 between the upper end portions 14 and 14 of the upper wings 5 and 5 and the spiral wing 3 and the interval T2 between the lower end portions 15 and 15 of the upper wings 5 and 5 and the lower wings 4 and 4 are as follows. When the distance H1 between the three is about 6400 mm, it is preferably about 450 mm to 750 mm, and it is desirable that the spiral wing 3 and the lower wings 4 and 4 are close to each other in terms of increasing excavation force and pushing force. .

  As described above, the upper wing 5 is provided with the inclined surface 11 inclined in a spiral shape having the same diameter as that of the spiral wing 3, thereby increasing the push-up force and forming a transfer path for smoothly transferring the excavated soil. can do. Further, by providing the upper end portion 14 and the lower end portion 15 so as to be substantially parallel to the horizontal direction in plan view, the inlets or outlets of the upper wings 5 and 5 acting as transfer paths are formed widely. A large amount of excavated soil can be sent. Further, the symmetrically provided upper wings 5 and 5 provided as a pair are provided such that the inclined surface 11 of one upper wing 5 and the inclined surface 11 of the other upper wing 5 overlap in a plan view. Thus, during excavation, the vertical and horizontal excavation force and stirring force can be increased, and the proof strength of the upper wing 5 can be increased. Further, the lower wing 4 is disposed so that the inclined surface 11 of one upper wing 5 and the inclined surface 11 of the other upper wing 5 overlap each other in plan view. The excavated soil can be smoothly fed to the upper wing 5.

  And the ground improvement excavation apparatus 1 provided with the said structure is used for the dry type deep ground improvement construction method, and builds a columnar improvement body as follows.

  First, when excavating the ground, the rotary rod 2 is rotated forward to press-fit the tip 12 into the ground, and the lower wings 4, 4 provided on the circumferential surface of the tapered portion 6 and the lower wings 4, 4. The upper wings 5 and 5 provided on the upper side in the vertical direction are excavated. At this time, the lower wings 4 and 4 are excavated while expanding the lower direction and the radial direction by the lower end portion 7 and the bent portions 10 and 10A of the side end portion 9, and at the same time, Transport excavated soil. Further, the upper wings 5 and 5 transfer the excavated soil transferred from the lower wings 4 and 4 to the spiral wing 3 while stirring the inclined surface 11, and the spiral wing 3 carries the excavated soil to the ground. The excavation of the ground and the transfer of excavated soil are performed efficiently.

  When the depth reaches a predetermined depth, an improved material obtained by mixing excavated soil and cement-based solidified material is put into the excavation hole on the ground. The improved material introduced into the excavation hole is sufficiently mixed and stirred by the lower wings 4 and 4 and the upper wings 5 and 5 by repeating forward and reverse rotations of the rotating rod 2.

  At the time of constructing the improved body, the rotating rod 2 is again rotated in the reverse direction to press-fit the tip 12 and the improved material that has been sufficiently mixed and stirred is put into the excavation hole. When introducing the improved material, the angle of the upper wings 5 and 5 is steep so that the pressure in the vertical direction increases, so that it does not rise due to the reaction force without being compressed in the radial direction. The lower wings 4 and 4 and the upper wings 5 and 5 act so that the radial consolidation is surely performed, and the columnar improvements are gradually built.

  As described above, the lower wings 4 and 4 and the upper wings 5 and 5 act at the time of excavation or construction of an improved body, so that the excavation force and the agitation force are reduced while generating little noise and vibration. In addition, since the pushing force is increased, excavation, agitation, and transfer of excavated soil can be efficiently performed, and only the lower wings 4 and 4 and the spiral wing 3 without the upper wings 5 and 5 are excavated. Compared with the apparatus, the work period can be shortened to about 1 / 1.5 to 1/2. Moreover, since the heavy machinery to be used is sufficient only with a construction pillar and a backhoe, it is possible to construct even a small land without requiring a large plant or the like. Further, by consolidating the improved material that has been sufficiently mixed and stirred, an improved product with uniform compressive strength can be built, and a high-quality columnar improved product can be built.

As described above, in this embodiment, the rotating rod 2 provided with the spiral blade 3, the lower blades 4, 4 provided in a pair below the rotating rod 2, and the axial direction lower side of the rotating rod 2 than the spiral blade 3. And a pair of symmetrical upper and lower wings 5 and 5 provided on the upper side in the axial direction of the rotating rod 2 with respect to the lower wings 4 and 4, and the lower wings 4 and 4 have a lower end 7 on one side in the rotational direction. And the lower end 7 of the lower wings 4, 4 are inclined downward from the taper 6 side of the rotating rod 2 toward the outer corner 8, Since the upper wings 5 and 5 are provided so that the upper end portion 14 and the lower end portion 15 are parallel to each other in plan view , the lower wings 4 and 4 and the upper wings 5 and 5 are provided. , Stirring force and push-up force are enhanced, by excavation of excavation hole, transfer of excavated soil, agitation of improvement material, and compaction of improvement material Densification is so performed efficiently, it is possible to shorten the construction period, the well mixed stirred improvement material can be construction quality improvement body for compacting the ground. Further, the excavation force in the vertical and horizontal directions can be increased during excavation, and the compaction force in the vertical and horizontal directions can be increased during construction of the improved body, so that an improved body having a substantially uniform compressive strength and a large outer diameter can be constructed.

  In this way, in this embodiment, the upper wing 5 has the same diameter in the horizontal direction as the spiral wing 3 and is inclined spirally up and down in the axial direction of the rotating rod 2. And the transfer path for smoothly transferring the excavated soil from the lower wing 4 to the spiral wing 3 or from the spiral wing 3 to the lower wing 4 can be formed.

In this way, in this embodiment, the upper wing 5 is formed on the peripheral surface of the rotating rod 2 so that one upper wing 5 and the other upper wing 5 overlap vertically in the axial direction of the rotating rod 2. Therefore, during excavation, the vertical and horizontal excavation force and stirring force can be increased, and the proof strength of the upper wing 11 can be increased. Further, the excavated soil can be smoothly transferred from the lower wing 4 to the spiral wing 3 or from the spiral wing 3 to the lower wing 4.

  The present invention is not limited to this embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, in this embodiment, the lower wings 4 and 4 and the upper wings 5 and 5 included in the excavation apparatus 1 for ground improvement are configured by two wings, but may be two or more wings. In addition, although the inclined surface 11 is provided with a steeper slope than the spiral blade 3, it can be appropriately changed according to the excavation force.

DESCRIPTION OF SYMBOLS 1 Ground improvement excavator 2 Rotating rod 3 Spiral wing 4 Lower wing 5 Upper wing
6 Taper 7 Lower end (lower wing)
9 Side edge (lower wing)
10, 10A bent part
11 Inclined surface
13 Flat part
14 Upper end (upper wing)
15 Lower end (upper wing)

Claims (3)

A rotating rod provided with a spiral wing, a pair of lower wings provided below the rotating rod, an axially lower side of the rotating rod than the spiral wing, and an axial direction of the rotating rod from the lower wing On the upper side, a pair of symmetrical upper and lower wings are provided , the lower wing is provided with a bent portion with a lower end and a side end inclined on one side in the rotational direction, and the lower end of the lower wing is The ground improvement is characterized in that the upper wing is inclined downwardly from the taper portion side of the rotating rod toward the outside, and the upper wing is provided so that the upper end portion and the lower end portion are parallel to each other in plan view. Drilling rig. Said upper wing, said helical with wings and a same diameter in the horizontal direction, vertical to the axial direction of the rotating rod and wherein the inclined helically claim 1 Symbol placement of soil improvement rig. Said upper wing, so as to overlap in the vertical in the axial direction of the rotating rod and one of the upper wing and the other of said upper wing, according to claim 2, characterized in that it is formed on the peripheral surface of the rotating rod Ground improvement drilling rig.

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