JP4185998B2 - Construction method of excavation rod and foundation pile - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, architecture, used to construct the foundation piles in the field of civil engineering, etc., method for constructing a foundation pile characterized by a formation of Kuianakabe relates to drilling rod de used in the construction process.
[0002]
[Prior art]
The applicant has been constructing a kneading method (Trademark of Mitani SEXAN) for many years, in which a ready-made pile is embedded in a pile hole formed by kneading the hole wall (Patent Document 1).
[0003]
The excavation rod used in this pile hole forming method has an excavation head at the tip, and a stirring bar and a kneading drum are attached to the excavation head at predetermined intervals. The ground was excavated while pouring water with the excavating head, and this excavated mud was stirred with the stirring bar, and the mud was kneaded with the inner wall of the pile hole while rotating with the kneading drum, thereby solidifying the inner wall of the pile hole. Kneading with a kneading drum leveled the inner wall of the pile hole and arranged the pile hole into a predetermined shape to improve the quality of the foundation pile. Moreover, the inner wall of the pile hole was leveled with a drum to prevent the inner wall from collapsing, and when the ready-made pile was then pushed into the pile hole, the pressing resistance was reduced and the ready-made pile was easily set. Furthermore, the discharge of excavated soil was reduced by an amount equivalent to kneading by leveling the inner walls of the pile holes with a drum.
[0004]
In this case, with respect to the shape of the kneading drum attached to the conventional excavation rod, for example, the kneading plate corresponding to the kneading drum has a cylindrical body or arc-shaped piece whose pile hole inner diameter (excavation diameter) is substantially equal to the outer diameter. (Patent Document 2). That is, the kneading part is curved with respect to the inner wall of the pile hole, and has a kneading part structure that is rotated by the rotation of the excavating rod to press the excavated soil against the pile hole wall as a smooth kneading surface (Patent Document 2). In particular, FIGS. 1 and 2).
[0005]
Moreover, in patent document 3, the pile hole of a predetermined dimension is excavated by the same method as the above-mentioned, the mixing method of cement milk and excavated soil is devised, a high quality soil cement layer is formed, and the ready-made pile is sunk. . In this case as well, the shape and angle of the kneading surface of the kneading drum are devised, but it is the same as in Patent Documents 1 and 2 in that a smooth kneading surface is formed.
[0006]
[Patent Document 1]
JP 55-45960 A
[Patent Document 2]
JP 61-1113925 A
[Patent Document 3]
JP 2002-317594 A
[Problems to be solved by the invention]
In the conventional method for creating a pile hole using a drilling rod with a kneading drum, excavation and kneading work during excavation can be performed smoothly, and a pile hole of a predetermined quality with a uniform inner wall can be created. A large amount of water injection was required. Therefore, a large amount of excavated soil corresponding to the amount of water injection had to be discharged on the ground. Therefore, in order to reinforce the peripheral frictional force of the ready-made pile buried in the pile hole shaft filled with soil mud, the soil mud layer of the shaft in the pile hole is filled with cement milk to form a soil cement layer. It was also made to retain the solidification strength.
[0010]
Also, the excavated mud mixed with cement milk must be treated as industrial waste, and as a result, the excavated mud mixed with cement milk can be treated, so that a treatment plant is installed at or on site. However, there is a need to dispose of the waste as industrial waste.
[0011]
Therefore, even if a pile hole is excavated without water injection at the time of excavation, the pile hole does not collapse and a construction method that can create a pile hole of a predetermined quality is required.
[0012]
[Means for Solving the Problems]
However, in the present invention, since the pile hole is excavated using the kneading drum having the excavation auxiliary means such as the ridges, the above-mentioned problems have been solved.
[0013]
That the invention has a drilling head of the drilling diameter D ₁ at the tip, a drill rod having a kneading with drum above the該掘cutting head, the batter with drum surface with kneading along Kuianakabe The ridges in the axial direction of the excavation rod are arranged in parallel with the circumferential direction of the excavation rod at a predetermined interval on the kneading surface, and the ridges excavate the pile hole wall. And forming a recess capable of accumulating excavated soil and dropping it downward between the ridges , and forming the outer diameter of the ridge of the kneading drum as D ₄ and D ₄ > D ₁
The kneading drum is a drum mounting portion arranged at the same height and symmetrical diameter on the rod body, and is configured by projecting two fixing plates radially fixed to the rod body. The drilling rod is characterized in that the kneading surface is formed on the drilling rod.
[0014]
In the above, the kneading surface is a drilling rod characterized in that the lower end portion is gradually reduced in diameter toward the axis of the rod to form the introduction portion, and the lower end of the protrusion is positioned at the introduction portion. .
[0015]
In another invention, a drilling rod having a drilling head at the lower end and a kneading drum above it is used to drill a pile hole, followed by a solidified layer including a soil cement layer. A method of constructing a foundation pile by substituting a ready-made pile in the formed pile hole, wherein the excavation head excavates with a diameter smaller than a required pile hole diameter, and then kneading a kneading drum in the axial direction of the ridges of the drill rod which is formed on a facing the pile hole wall and pooled excavated soil in a recess formed between the ridges, is dropped the excavated soil downwards, given the Kuianakabe pile A method of expanding the hole diameter and leveling the wall of the pile hole , wherein the kneading drum is a drum mounting portion disposed at the same height and symmetric in diameter on the rod body, The drum mounting portion formed by projecting two fixing plates fixed radially is provided with the above-mentioned kneading. A method for constructing a foundation pile, characterized in that constructed by forming a surface.
[0016]
Moreover, another invention is a construction method of a foundation pile characterized by excavating a pile hole axial part and burying a ready-made pile as follows.
(1) using the drill rod having a paste with drum kneaded with diameter D ₄ above the drilling head of a predetermined excavation diameter D _1, by rotating the該掘cutting rod, to pile holes drilled with the drilling head.
(2) kneading with diameter D ₄ is formed to have a larger diameter than the drilling diameter D _1, said been diameter D ₁ of the pile hole wall drilled with the drilling head, the drill rod formed in kneading with surface of the kneading with the drum cut with the axial direction of the ridges, and pooled excavated soil in a recess formed between the ridges, is dropped the excavated soil downward, expanding the Kuiana径the diameter D _4, smoothed out Kuianakabe Te, to form a Kuiana shank of diameter D _2.
(3) A solidified material layer including a soil cement layer is formed in the pile hole, and a ready-made pile is set in the pile hole.
(Four) The kneading drum is a drum mounting portion arranged at the same height and symmetrical diameter on the rod body, and is configured by projecting two fixing plates radially fixed to the rod body. And forming the kneading surface.
[0017]
Further, in the above, the kneading with surface as drilling aid, the longitudinal ridges formed in the projecting strip, cutting the pile hole wall of diameter D _1, expanding the diameter D _4, Kuianakabe It is the construction method of the foundation pile characterized by leveling. Further, above the kneading with the drum of the drilling and milling with diameter D _4, it is kneaded with diameter _{D 3 (D 3 <D 4} ) mixing with drum installed foundation piles leveling the pile hole wall building method . Moreover, it is the construction method of the foundation pile which excavates a pile hole, without supplying a water | moisture content in a pile hole, and equalizes the hole wall of the said pile hole, without supplying a water | moisture content in a pile hole continuously. Furthermore, when excavating the side closer to the ground of the pile hole, the excavated soil corresponding to the amount of cement milk to be input is discharged to the ground, and the excavated soil is not discharged to the ground during the subsequent excavation. It is the construction method of the foundation pile to do.
[0018]
The solidified material layer mentioned above is a layer solidified to a predetermined solidification strength in the pile hole, and refers to a soil cement layer in which excavated mud and cement milk are mixed, a cement milk layer in which excavated mud is replaced, and the like.
[0019]
The rotation direction of the excavation rod is a circumferential direction substantially orthogonal to the axial direction and refers to the rotation direction when the excavation rod rotates.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
(1) When excavating the pile hole shaft, the excavation head at the tip of the excavation rod is excavated with substantially the same diameter as the maximum diameter of the ready-made pile to be submerged without water injection for excavation. When the ready-made pile is a ready-made pile with a protrusion such as a so-called joint pile, the outer diameter of the protrusion is the maximum outer diameter.
[0021]
Excavation of pile holes with the excavation blade of the excavation head at the tip of the excavation rod, and the vertical ridge as a finishing blade (excavation aid) of the kneading drum attached directly above the excavation head with the excavation rod Parallel to form radially. The outer diameter of the tip of the ridge is the same as the outer diameter of the excavation (here, approximately the same as the maximum outer diameter of the ready-made pile), and the pile hole wall is leveled while excavating by shaving the pile hole wall.
[0022]
At this time, the pile hole wall is shaved with the ridges, and the shaved soil is collected in the recesses between the ridges. Sequentially, newly shaved soil is accumulated, and the accumulated soil falls downward.
[0023]
(2) Pile hole excavation with approximately the same diameter as that of the ready-made pile, and further expanding the inner wall of the pile hole using the improved drum mounted on the upper part of the pile, and performing final excavation with a predetermined pile hole diameter, and excavating soil in the recess Embed. Further, the excavated soil is further stirred by the stirring rod and the kneading drum mounted on the upper part and pushed into the pile hole wall.
[0024]
(3) Cement milk is poured into the lower end of the excavated pile hole in this way to form a rooted portion, and a ready-made pile with protrusions is buried in the pile hole to form a foundation pile structure.
[0025]
[Example 1]
Embodiments of the present invention will be described with reference to the drawings.
[0026]
[1] Configuration of excavation rod 40
(1) The excavation rod 40 of this invention connects the lower rod 10 equipped with the kneading drums 18 and 18 of the present invention to the lower end of the upper rod 35 equipped with ordinary kneading drums 38 and 38, and then The excavation head 1 is connected to the lower end of the lower rod 10 (FIG. 1). In this embodiment, two lower rods 10 and 10 are connected to the excavation head 1, and a predetermined number of upper rods 35 and 35 are connected to the lower rods 10 and 10.
[0028]
Drilling head 1 is formed by drilling diameter _{D 1.} The length in the vertical direction (in the axial direction of the rod body) of the outer bent plate 25 of the kneading drum 18 is L ₂ (L ₂ = 330 mm). The length of the vertical direction of the ridges 30 (in the axial direction of the rod main body 11) is the same L _2.
[0029]
Moreover, the length of the rod main body 11 of the lower rod 10 is formed to be about 150 to 200 cm. In addition, when ground excavation with the excavating blades 5 and 5 of the excavating head 1 is not good, the excavated soil is not pulverized, and a stirring bar is provided at an appropriate position above and below the kneading drum 18 to supplement the excavated soil. (Not shown). In this case, the length of the rod body 11 is increased.
[0030]
(2) Configuration of the excavation head 1 [0031]
The excavation head 1 is formed with a connecting portion 3 for connection with rod main bodies 11 and 36 at the upper end of a hollow cylindrical head main body 2, and around the head main body 2, a spiral 4 for excavation with an outer diameter D ₁ , 4 is formed, and the fixed excavating blades 5 and 5 are formed at the lower ends of the spirals 4 and 4 with the cutting edges projecting downward (FIG. 1). Moreover, the expansion excavation blades 6 and 6 which rotate around the axis 7 and expand in the radial direction (lateral direction) are attached to an intermediate portion of the spiral 4 (FIG. 1).
[0032]
The fixed digging blade 5 has a tip L of the fixed digging blade 5a located on the outermost side (outer peripheral side), which is in contact with the pile hole wall to excavate the hole wall in the vertical direction (axial direction of the head body 2). ₁ is formed. Further, since the number n of the excavating means is the number of the outer fixed excavating blades 5a, n = 2.
[0033]
Also formed in the (axial direction of the head body) length L ₃ vertical portion edge of the enlarged digging edge 6 is drilled to contact with the hole wall pile hole wall. Therefore, the number n of excavation means for excavating the pile hole wall during the expansion excavation is also (n = 2).
[0034]
In addition, a water injection port (not shown) is provided at the center of the lower end of the head body 2 so that necessary amounts of water and cement milk can be appropriately injected from the outside through the hollow portions of the rod bodies 36 and 11 while excavating. It has become.
[0035]
(3) Configuration of the lower rod 10
Connecting portions 12 and 12 are formed on the upper and lower sides of the rod main body 11, respectively, and can be connected to the other rod main bodies 11 and 36 or the connecting portions 3, 12, and 37 of the head main body 2. Two fixing plates 14 and 14 having an angle θ (here, θ = 90 °) are radially projected from the rod body 11. On the outer surface of the rod body 11, the base end of a substantially fan-shaped support plate 15 disposed between the fixing plates 14 and 14 is fixed. Both end portions of the support plate 15 are fixed to opposing inner surfaces of the fixing plates 14 and 14. Further, three support plates 15 are arranged in parallel at the upper and lower end portions and the middle portion of the fixing plates 14, 14. A through hole 16 at the same position in the vertical direction is formed in the approximate center of each support plate 15.
[0037]
The fixed plates 14 and 14 and the support plates 15 and 15 constitute a drum mounting portion 13. The drum mounting portions 13 are arranged at two positions at the same height and symmetrical with respect to the diameter.
[0038]
The partial fan-shaped horizontal plates 19 and 19 formed by cutting the center side of the fan shape with a small-diameter fan are arranged in parallel vertically, and both straight portions (radius portions) of the parallel horizontal plates 19 are connected by the vertical plates 20 and 20, respectively. The partially cylindrical inner bent plate 21 is fixed to the inner peripheral side of the horizontal plate 19, and the partially cylindrical outer bent plate 25 is fixed to the outer peripheral side of the horizontal plate 19. A gap 22 into which the intermediate support plate 15 of the drum mounting portion 13 can be inserted is formed at the center of the inner bending plate 21, and a partial fan-shaped small side is formed above and below the gap 22 on the inner surface of the inner bending plate 21. The plates 23, 23 are provided so as to fix the straight portion (radius portion) of the small horizontal plate 23 to the inner surface of the vertical plate 20.
[0039]
Through holes 24 and 24 corresponding to the through holes 16 of the support plates 15 and 15 are formed in the horizontal plate 19 and the small horizontal plate 23 so as to communicate vertically.
[0040]
At the upper edge of the outer bent plate 25, a bent plate-like introduction portion 26 that gradually becomes smaller in diameter is provided continuously. Similarly, a bent plate-like introduction portion 27 that gradually decreases in diameter toward the lower side is continuously provided at the lower edge of the outer bent plate 25.
[0041]
Longitudinal protrusions 30 and 30 are fixed to the outer surface of the outer bent plate 25 in parallel in the rotating direction of the outer bent plate 25 (that is, the rotating direction of the excavating rod 40). The upper edge 31 of the ridge 30 is positioned near the upper edge of the outer bent plate 25, the lower edge 31a is positioned on the outer surface of the lower introduction portion 27, and the lower end portion is bent along the outer surface of the introduction portion 27. is there. The protrusion 30 has a square cross section and is formed at a height H from the outer surface of the outer bent plate 28. A gap 33 is formed between the protrusions 30 and 30, and the width P of the gap 30 is at least P> H. It is desirable to form with. Also, the longitudinal length of the straight portion of the protrusion 30 (the outer bent plate 25 portion) and L _2.
[0042]
Further, the exposed surface 32 (front surface 32a and side surface 32b) of the protrusion 30 is subjected to a surface treatment for preventing peeling (for example, CRH-4 of Tokuden Co., Ltd.). A kneading surface is constituted by the exposed surface 32 of the protrusion 30 and the exposed outer surface of the outer bent plate 25.
[0043]
The kneading drum 18 is configured as described above (FIG. 2).
[0044]
The kneading drum 18 is attached to the drum attachment portion 13. At this time, the inner bending plate side 21 of the kneading drum 18 is inserted between the fixing plates 14 and 14 of the drum mounting portion 13 so that the upper and lower support plates 15 and 15 and the horizontal plates 19 and 19 face each other, The support plate 15 is inserted into the gap 22 so as to be sandwiched between the small horizontal plates 23 and 23. The pin 34 is inserted into the through holes 16 and 24 that communicate with each other, and the kneading drum 18 is fixed to the drum mounting portion 13 (FIG. 3).
[0045]
The lower rod 10 is configured as described above (FIG. 1).
[0046]
(4) Configuration of upper rod 35
The kneading drum 38 used for the upper rod 35 is configured by removing the protrusions 30 and 30 from the kneading drum 18 of the lower rod 10. Similar to the lower rod 10, the upper rod 35 is configured by fixing the kneading drums 38 and 38 to the drum mounting portion 13 of the rod main body 36 having upper and lower connecting portions 37 and 37 with pins (FIG. 1). Kneading with the diameter of the mixing with the drum 38 (the maximum outer diameter) and D _3.
[0048]
(5) Each dimension ・ Diameter of spiral D ₁ of drilling head ₁ = 630 mm
-Length L ₃ of fixed excavation blade of excavation head 1 = 50 to 100 mm
・ Maximum diameter D ₄ = 730 mm including the protrusion 30 of the kneading drum 18
・ Height H = 50 mm of the protrusion 30 of the kneading drum 18
-Vertical length L ₂ of the ridge 30 of the kneading drum 18 = 330 mm
· The outer diameter of the kneading with the drum 38 _D 3 = 630 mm
The distance L ₅ = 1250 mm between the fixed excavation blades 5 and 5a of the excavation head 1 and the lower end of the kneading drum of the lower rod
About distance _L 6 = 2000 mm of the upper and lower-kneaded with drums 18 and 38 In the case where the kneading with the drum 18 and 38 providing a stir bar, a maximum of _L 6 = 5000 mm approximately.
[0049]
[2] Drilling method
(1) The excavation rod 40 is rotated at a rotational speed N (rpm) at the planned construction position of the foundation pile, and the excavation head 1 is rotated to excavate the pile hole shaft portion with the fixed excavation blades 5 and 5a. Especially, the outer fixed digging edge 5a, as discouraging the pile hole wall with a length L _1, drilling loosen the excavated soil. At this time, water for digging assistance is not poured from the digging head.
[0051]
At this time, since the excavated soil is unloaded from the periphery of the fixed excavation blades 5 and 5a by the spirals 4 and 4, the excavation efficiency by the fixed excavation blades 5 and 5a is increased. Stay up.
[0052]
Also, since the excavated soil on the surface side is less strong than the intermediate depth of the ground and the supporting ground, only the excavated soil on the surface side is discharged to the ground by an amount corresponding to the amount of cement milk to be injected later. . This excavated soil is treated as general soil. The excavated soil is not discharged at a depth after this depth.
[0053]
(2) Subsequently, the pile hole wall is further expanded by the kneading drum 18 of the lower rod 10 on the lower side, and the pile hole wall is leveled while the excavated soil is pressed against the pile hole wall.
[0054]
At this time, the pile hole wall is expanded by the surface of the ridge 30 because the ridge 30 is formed to have a diameter (D ₄ ) larger than the digging diameter D ₁ of the fixed digging blade 5 a by the height H. The excavated excavated soil is buried in the recesses formed by the gaps 33, 33 between the ridges 30, 30. The excavated soil in the recess is sequentially discharged into the pile hole, but is stirred together with the other excavated soil by the kneading drums 18 and 38 and is pushed into the pile hole wall by the kneading drums 18 and 38.
[0055]
(3) Subsequently, the upper lower rod 10 is also operated in the same manner, and in the same manner as the kneading drum 18 of the lower lower rod 10, the pile hole wall left expanded is excavated, and the pile hole wall It was extended to the diameter D _4, even out Kuianakabe.
[0056]
In the subsequent kneading drum 38 of the upper rod 35, the excavated soil staying in the pile hole wall is pushed into the pile hole wall by the outer bent plate 25, and the pile hole wall is further leveled.
[0057]
(4) When the excavation of the pile hole shaft portion 42 having the diameter D ₂ (= D ₄ ) is completed, the excavation rod 40 is reversely rotated, and the enlarged excavation blades 6 and 6 are rotated around the shaft 7 to be opened. Then, the bottom of the pile hole shaft 42 is excavated at the bottom of the pile hole.
[0058]
After the completion of excavation of the pile hole, cement milk is extracted from the spout at the lower end of the excavation head 1, and a solidified layer of soil cement or cement milk is formed on the bottom of the pile hole. Moreover, a pile periphery fixed liquid layer by soil cement is formed in the pile hole shaft.
[0059]
After forming the root consolidation layer and the pile periphery fixing liquid layer, or while forming, the excavation rod is pulled up to the ground, and then the prefabricated pile is submerged in the pile hole while being rotated and installed at a predetermined position.
[0060]
(5) The excavation by the fixed excavation blade (excavation blade for inner wall of the pile hole) 5a of the excavation head 1 is excavated so that the excavation of the pile hole is complemented by the protrusion 30 of the kneading drum 18.
[0061]
Rotational speed N of the drill rod 40 to schedule (rpm), the pushing speed v of the drill rod 40 with respect to (cm / min), the length _{L 1} of the fixed digging edge 5a, the length _{L 2} of the kneading with the drum 18, The length L3 of the enlarged excavation blade 6 is set to L ₁ and L ₂ so as to satisfy the following relational expression, or the rotation speed N and the pushing speed v of the excavation rod are adjusted so as to satisfy the relational expression. It is desirable.
[0062]
L ₁ ≧ v ÷ (n ₁ × N) Equation 1
L ₂ ≧ v ÷ (n ₂ × N) Equation 2
L ₃ ≧ v ÷ (n ₃ × N) Equation 3
Here, n ₁ is the number of fixed excavating blades 5a having the same height (n ₁ = 2), n ₂ is the number of protrusions 30 having the same height (n ₂ = 8), and n ₃ is the same height This represents the number of enlarged excavating blades 6 (n ₃ = 2).
[0063]
If this relational expression is satisfied, the fixed excavation blade 5a and the protrusion 30 cut the pile hole wall at least once, so that the pile hole wall can be excavated without leakage. Moreover, if this relational expression is satisfied, the excavating blade cuts the pile hole wall at least once, so that the pile hole wall can be excavated without leakage.
[0064]
In addition, depending on the construction ground, even when the formula 1 is not satisfied when excavating the pile hole,
L ₂ = v ÷ (n ₂ × N)
On the other hand, if L ₂ is formed so as to be about three times as long as that, or if the number of the ridges 30 is increased within a range in which the predetermined gap 33 can be maintained, the ridges 30 of the kneading drum 18 are It is also possible to create a desired high quality pile hole by finishing excavation and kneading three times to supplement the excavation of the excavation head.
[0065]
In addition, if considering only the quality of the pile hole without considering the construction efficiency, the speed v can be made as slow as possible (for example, about one third) by the above formulas 1 and 2, and the drilling of the pile hole can be performed. desirable. In particular, in excavation of a pile hole widening part, it is desirable to satisfy | fill Formula 3 and excavate at the slowest possible speed v.
[0066]
(6) In the above, it is desirable to excavate without injecting water into the pile hole. However, when a situation in which excavation is difficult during excavation occurs due to the situation of the construction ground, the specific ground (horizontal position) Alternatively, it is possible to level the pile hole wall by excavating only a specific layer (depth position) while water is partially poured. That is, by adopting the construction method described above, it is possible to eliminate almost all of the soil discharged by pile hole excavation, except for the equivalent amount of cement milk, water, etc. to be injected separately.
[0067]
[3] Other embodiments
(1) The configuration of the kneading drum 18 is arbitrary as long as a kneading surface in which the protrusions 30 and 30 arranged in parallel in the circumferential direction of the rod body 11 are formed on the outer surface of the outer bending plate 25, The structure of the drum mounting portion 13 of the corresponding rod body 11 is also arbitrary (not shown).
[0069]
(2) Moreover, in the said Example, the upper rod 35 is what is called a conventional rod, the structure of the kneading drum 38 is arbitrary, and can also install an agitation bar (not shown). The upper rod 35 may omit the kneading drum 38 and the drum mounting portion 13 (not shown).
[0070]
(3) Moreover, in the said Example, although the two lower rods 10 which have the kneading drum 18 were connected, they can also be made into one (not shown). When it is necessary to further increase the pulverization of excavated soil, a stirring bar can be appropriately provided on the rod body 11 (not shown). By pulverizing the excavated soil more finely, the amount of excavated soil pushed into the pile hole wall can be adjusted.
[0071]
(4) In the above described embodiment, although the kneading with the drum 18 to lower rod 10 attached 1 setup, the kneading with the drum 18 can also be formed in two stages with a predetermined spacing L _6, in this case, More excavated soil can be pushed into the pile hole wall and the pile hole wall can be evened more evenly (not shown).
[0072]
【The invention's effect】
(1) This invention excavates with an excavation head having a diameter smaller than a predetermined pile hole diameter, and constructs a pile hole with a predetermined diameter by expanding the pile hole wall with the auxiliary excavation means of the kneading drum in the middle part. Efficient pile hole excavation can be realized by reducing the load acting on the tip of the rod.
[0073]
(2) Pile hole excavation can be done without water injection on the ground with relatively good grindability such as sandy soil, so the amount of excavated soil can be greatly reduced, and the amount of discharged soil can be at most used to form a solidified layer. The amount of cement milk can be reduced to the same level.
[0074]
(3) When a drilling auxiliary means is constructed by forming the axial ridges of the drilling rod on the kneading surface of the kneading drum, the pile hole wall into which the drilling soil has been pushed in is sufficiently smooth and strong. Therefore, there is an effect that the pile hole wall becomes smooth and it is easy to sink the ready-made pile after the formation of the pile hole.
[0075]
(4) When excavating pile holes and pushing in excavated soil without water injection, the soil quality is stabilized and the frictional force around the pile is stabilized. Only a part of the excavated soil is discharged. Therefore, the excavated soil of the upper ground (surface side) that matches the amount of cement milk input in the root consolidation part should be discharged before cement milk is input, that is, when excavating the upper part of the pile hole (surface side). Thus, excavated soil that is not mixed with cement milk or the like can be discharged. Therefore, the soil can be discharged from the construction site as general treated soil.
[0076]
(5) Also, since only the excavated soil on the surface side of the pile hole is discharged, the soil of the upper layer of the shaft pile hole (generally not good from the viewpoint of bearing capacity) can be removed, so the pile circumference It is possible to replace the soil quality of the soil with a good ground below, and to stabilize the ground around the pile.
[0077]
(6) In addition, in the creation of a foundation pile structure, when using a deformed pile with an uneven shape such as a node on the outer surface of the ready-made pile as a ready-made pile, the ready-made pile will be compared with a simple cylindrical pile. Since the cross-sectional area of the pile hole corresponding to the cross-sectional area is large, there has been a relatively large amount of excavated soil and a large amount of excavated soil. Therefore, when a deformed pile is used in the foundation pile construction method of the present invention, it is particularly effective for reducing the amount of soil discharged.
[Brief description of the drawings]
FIG. 1 is a front view of a drilling rod using a kneading drum according to an embodiment of the present invention.
2A is a front view, FIG. 2B is a plan view, and FIG. 2C is a cross-sectional view taken along line AA.
FIGS. 3A and 3B are views for explaining the connection between the kneading drum and the rod body of the present invention, wherein FIG. 3A is a plan view and FIG.
[Explanation of symbols]
1 Excavation head 2 Head body (Excavation head)
3 Head body connection 4 Spiral (Drilling head)
5 fixed excavation blade (excavation head)
5a Fixed excavating blade (outside)
6 Expansion drilling blade (Drilling head)
10 Lower rod 11 Rod body (lower rod)
12 Connecting part (lower rod)
13 Drum mounting part (lower rod)
18 Kneading drum (lower rod)
25 Outer bending plate (lower rod)
26 Introduction part (upper and lower rod)
27 Introduction part (bottom, lower rod)
28 Exposed surface 30 of outer bent plate ridge (lower rod)
31 Upper edge 31a of the ridges Upper edge 32 of the ridges Exposed surface 32a of the ridges Front (exposed surface) of the ridges
32b Side surface of exposed ridge (exposed surface)
33 Projection gap 34 Pin 35 Upper rod 36 Rod body (upper rod)
37 Connecting part 38 Kneading drum 40 Drilling rod

Claims (7)

Has a drilling head of the drilling diameter D ₁ at the tip, a drill rod having a kneading with drum above the該掘cutting head, the batter with drum has a kneading with surfaces along the Kuianakabe, the The ridge in the axial direction of the excavation rod is arranged on the kneading surface in parallel with the circumferential direction of the excavation rod at a predetermined interval, the ridge excavates the pile hole wall, and the ridge during and pooled excavated soil to form a recess can fall down, and the outer diameter of the protrusion of the dough with the drum as D _4, formed by D _4> D ₁
The kneading drum is a drum mounting portion arranged at the same height and symmetrical diameter on the rod body, and is configured by projecting two fixing plates radially fixed to the rod body. A drilling rod characterized in that the kneading surface is formed on the drilling rod.   The drilling rod according to claim 1, wherein the kneading surface gradually reduces the diameter of the lower end portion toward the axis of the rod to form an introduction portion, and the lower end of the protrusion is positioned at the introduction portion. . A drilling rod having a drilling head at the lower end and a kneading drum above it is used to drill a pile hole, and subsequently in the pile hole in which a solidified layer including a soil cement layer is formed, A method of constructing a foundation pile by substituting a ready-made pile, wherein the excavation head is excavated with a diameter smaller than the required pile hole diameter, and then the excavation rod formed on the kneading surface of the kneading drum cutting the pile hole wall in the axial direction of the ridges, and pooled excavated soil in a recess formed between the ridges, it is dropped the excavated soil downwards, while expanding the Kuianakabe a predetermined Kuiana diameter, A method of leveling the pile hole wall ,
The kneading drum is a drum mounting portion arranged at the same height and symmetrical diameter on the rod body, and is configured by projecting two fixing plates radially fixed to the rod body. A method for constructing a foundation pile, characterized by comprising forming the kneading surface on the ground. A construction method of a foundation pile characterized by excavating a pile hole shank and burying a ready-made pile as follows.
(1) using the drill rod having a paste with drum kneaded with diameter D ₄ above the drilling head of a predetermined excavation diameter D _1, by rotating the該掘cutting rod, to pile holes drilled with the drilling head.
(2) kneading with diameter D ₄ is formed to have a larger diameter than the drilling diameter D _1, said been diameter D ₁ of the pile hole wall drilled with the drilling head, the drill rod formed in kneading with surface of the kneading with the drum cut with the axial direction of the ridges, and pooled excavated soil in a recess formed between the ridges, is dropped the excavated soil downward, expanding the Kuiana径the diameter D _4, smoothed out Kuianakabe Te, to form a Kuiana shank of diameter D _2.
(3) A solidified material layer including a soil cement layer is formed in the pile hole, and a ready-made pile is set in the pile hole.
(Four) The kneading drum is a drum mounting portion arranged at the same height and symmetrical diameter on the rod body, and is configured by projecting two fixing plates radially fixed to the rod body. And forming the kneading surface. Above the kneading with the drum of the drilling and milling with diameter D _4, the construction of kneading with diameter _{D 3 (D 3 <D 4} ) foundation pile according to claim 4, wherein the kneading with drum installed level the pile hole wall Method.   The construction method of the foundation pile of Claim 3 or 4 which excavates a pile hole without supplying a water | moisture content in a pile hole, and equalizes the hole wall of the said pile hole without supplying a water | moisture content in a pile hole continuously.   When excavating the side closer to the ground of the pile hole, the excavated soil corresponding to the amount of cement milk to be input is discharged to the ground, and the excavated soil is not discharged to the ground during the subsequent excavation. The construction method of the foundation pile of claim | item 3 or 4.

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