JP4103105B2 - Pile hole wall kneading equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention adopts a pile hole excavation method corresponding to the stratum, that is, the soil strength, and kneads the generated mud as much and efficiently as possible to reduce waste mud and strengthen the pile hole. Pile The present invention relates to a hole wall kneading apparatus.
[0002]
[Prior art]
Conventionally, for excavation of pile holes, after excavating the pile hole, the drill rod is taken out from the pile hole, and then the ready-made pile is buried (a pre-drilling method), A method of burying and lifting a drill rod through a hollow portion to complete pile hole excavation and sinking a pile (medium digging method) has been performed.
[0003]
In this case, when excavating a pile hole, a drilling fluid such as water may or may not be used. Also, the excavated soil was kneaded to the pile hole wall with a kneading drum.
[0004]
In drilling a pile hole, whether or not to use the drilling fluid is generally judged at the whole construction site, and all the piles at the construction site are determined uniformly. In addition, for example, even in individual conventional pile hole excavation, there is no simple criterion for determining when to use drilling fluid such as water.
[0005]
[Problems to be solved by the invention]
The first problem when the drilling fluid was not used properly was the treatment of muddy water.
[0006]
That is, when the drilling fluid is used there, the drilling fluid mixes with the drilling soil and becomes a large amount of mud and overflows on the ground.
[0007]
Generally, cement-based solidifying material is added to mud and solidified, and disposed as industrial waste as a viscosity that can be transported by truck, but this is not environmentally preferable. There is also a method of dewatering muddy water and reusing the soil, but there are problems such as requiring a large-scale device to make the reuse effective and difficult to install at each site. . Also, the method of using excavated soil and cement milk to make soil cement and using it is diversified, but when a large amount of soil cement flows out to the ground due to the insertion of piles, this soil cement is Similarly, it is common to dispose as industrial waste.
[0008]
In addition, as a second problem, there was a point that contributed to the high retention of the pile. That is, despite the excavation of the pile hole to a predetermined depth, sand, gravel, etc. fall from the pile hole wall and accumulate at the bottom of the pile hole, and the lower end of the pile does not sink to the predetermined depth, and the upper end of the pile Is a surplus problem.
[0009]
That is, when more drilling fluid is injected than necessary, it is conceivable that the specific gravity of the mud in the pile hole decreases and gravel falls to the pile hole side. In addition, when the amount of drilling fluid injected is too small, the kneading of the pile hole wall may be incomplete, and a part of the pile hole wall may collapse. Furthermore, it is conceivable that the shape of the kneading drum is inappropriate and the excavated soil to be kneaded is not pressed against the pile hole wall and remains in the pile hole.
[0010]
Such a problem was conspicuous in the case of the pre-digging method, but was also the same problem in the medium-digging method.
[0011]
Therefore, it has been demanded to select and use an appropriate drilling fluid suitable for the soil strength and to clarify a drum structure capable of efficient kneading.
[0012]
In addition, the conventional method of using a kneading means such as a kneading drum has had a great effect, but further research and development on the shape of the drum allows it to be kneaded to the pile hole wall even when drilling fluid is not used. In addition, it has been required to increase the amount of kneading and to further increase the strength of the pile hole wall.
[0013]
[Means for solving the problems]
This invention, when excavating a pile hole, excavation is divided into excavation that does not require drilling fluid and necessary excavation, to reduce the generated mud as much as possible, and knead the excavated soil efficiently, They have succeeded in remarkably improving the conventional problems. In addition, when making soil cement, a soil cement layer with the required strength is generated at the required location, and when the concrete pile is inserted, all of the soil cement is prevented from flowing out of the pile hole or as much as possible. A groundbreaking construction method was completed that managed and allowed construction to proceed automatically.
[0014]
That is, This invention A drilling rod that connects a drilling head having a drilling blade at the tip and has a kneading drum that abuts against the pile hole wall, and is drilled while rotating, the kneading drum entering at least the kneading soil to be kneaded Widen the gap with the pile hole wall on the side to be made, and form a small gap with the pile hole wall toward the other side kneaded to a predetermined pile hole diameter, and the kneading drum has a longitudinal direction of the excavation rod On the other hand, an outer wall surface is formed so that a gap with the pile hole wall decreases from the lower end surface toward the upper end surface, and the cross-sectional area gradually increases. This is a kneading device.
[0015]
According to another invention, in the excavation rod for excavating while rotating a drilling head having a drilling blade at the tip, a kneading drum is fixed at predetermined intervals, and at least one of the kneading drums is A kneading drum having an outer wall surface formed so that a cross-sectional area gradually increases from the left side to the right side with respect to the longitudinal direction of the excavation rod, and the kneading drum corresponds to the longitudinal direction of the excavation rod. The pile hole wall is characterized in that an outer wall surface is formed so that a gap with the pile hole wall decreases from the lower end surface toward the upper end surface and the cross-sectional area gradually increases. Attachment device.
[0016]
In the above description, the integrated current value includes an integrated torque value of the same value.
[0017]
Also, Construction of this invention The drilling is divided into the case of using the drilling fluid and the case of not using the drilling fluid, not to mention that it is applied to every single pile hole at a certain building construction site. It is also possible to apply each part.
[0018]
This invention Construction Whether or not the bearing capacity is expected is closely related to the soil strength (for example, N value), and the strata that do not expect the bearing capacity are, for example, a sandy soil layer with an N value of less than 15, and a viscous soil layer with an N value. A stratum having a value of less than 10 is a stratum that consumes relatively little power consumed by the rotary drive device for the excavating rod during excavation. Originally, the N value in the standard penetration test may vary greatly even with the same quality of formation, and it is difficult to determine it in general. However, the average N value is calculated by eliminating the abnormal N value due to rolling stones, and the average value of the N value. However, it has been found that if the sandy soil layer has an N value of less than 15 and the viscous soil layer has an N value of less than 10, it almost coincides with the difficulty of excavating the soil. Since the N value is almost proportional to the power used during excavation, if the power used or the integrated current value proportional to the power is displayed in parallel with the N value graph by depth, the N value and power As the excavation becomes clear, the soil quality can be estimated. Therefore, when the soil strength is small, the excavation can proceed without using the excavation liquid.
[0019]
In the construction of this invention, In the excavation of the pile hole, it is possible to easily use the drilling fluid with the same drilling head. For example, in one pile hole, drilling is performed without drilling fluid up to 3 m from the ground surface. It is possible to easily change the excavation method such as drilling without using the drilling fluid up to 3m to 5m and further using the drilling fluid up to 5m to 8m.
[0020]
Also , The discharge amount of drilling fluid or the discharge amount of cement milk is set in the computer in advance corresponding to the drilling state, and the best drilling fluid amount is determined according to the drilling state and its progress state, or the discharge amount of cement milk Can be controlled to adjust the solidification strength of the soil cement at each depth. Therefore, the foundation pile is managed by computer from pile hole excavation to soil cement layer formation, and the best foundation pile structure according to the soil strength of each layer can be realized.
[0021]
By rationalizing the excavation of the pile holes as described above, not only can the amount of muddy water discharge be minimized, but also the strength of the pile hole walls and the support capacity of the foundation piles can be improved, and by selecting the construction method at the construction site. Can build an ideal foundation pile structure.
[0022]
In the construction of this invention Even in the case of a formation having a high kneading resistance (for example, a viscosity layer), if the drilling fluid is used for the drilling auxiliary means, the pile hole can be drilled efficiently and easily with a relatively small electric power.
[0023]
In the construction of this invention, The stratum expecting bearing capacity is a stratum having an N value of 15 or more for a sandy soil layer, an N value of 10 or more for a viscous soil layer, for example, and the power consumed by the rotary drive device for the excavating rod is relatively large. A stratum that takes a long time to dig.
[0024]
Moreover, the support force here includes a pile peripheral surface support force and a pile tip support force.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, in one pile hole, a stratum that does not expect a supporting force is excavated without using a drilling fluid such as water, and a stratum that expects a supporting force uses a drilling fluid such as water as a drilling auxiliary means. The excavated soil generated by the excavation is pressure-kneaded to the hole wall by a kneading drum fixed to the rod to excavate the pile hole.
[0026]
Cement milk is poured into the remaining excavated soil in the pile hole, stirred to form a soil cement, a concrete pile is inserted into the pile hole, and the soil cement is filled inside and outside the concrete pile. It is the construction method of the pile.
[0027]
The discharge amount of the drilling fluid or cement milk is controlled by a computer, and the drilling fluid is not only used or not used, but also controls the discharge amount as described above (for example, control in relation to the magnitude of the N value). Try to get the best effect with drilling fluid. Also, for cement milk, the best foundation pile structure can be obtained by assuming the strength of soil cement according to the nature of the excavated soil (geology) and the depth of the pile hole, and controlling the discharge rate of cement milk to match this. It is a construction method that can be done. In addition to controlling the discharge amount of cement milk, the concentration of cement milk, the type of drilling fluid, and the like can be switched as necessary, and these can be automatically controlled.
[0028]
Further, the agitating means is attached to the excavation rod at predetermined intervals, and the kneading drum is fixed at every predetermined interval. At least one of the kneading drums is a pile hole on the side where the excavating soil to be kneaded enters as a structure. Under the technical idea of widening the gap with the wall and further reducing the gap toward the other side to be kneaded to a predetermined pile hole diameter, and in accordance with the desired finishing condition of the kneading, specifically the excavation A kneading drum in which the outer wall surface is formed so that the cross-sectional area gradually increases from the lower end surface toward the upper end surface and the cross-sectional area gradually increases from the left side surface toward the right side surface with respect to the longitudinal direction of the rod. This is a foundation pile kneading device. According to the apparatus, the excavated soil can be kneaded efficiently, and the excavated soil can be agitated by the agitating means to mix the soil cement, thereby making the soil cement homogeneous.
[0029]
In addition, when the drum kneading surface can be taken widely, on the side where the excavated soil enters as described above, the drum diameter is reduced to widen the gap with the pile hole wall to facilitate the entry of the excavated soil. In addition, a technique can be added in which the drum diameter is gradually increased toward the other side (exit side), the gap is reduced, and the kneading is performed with substantially the same diameter as the excavation diameter. Further, the diameter of the drum is substantially the same as the excavation diameter at the intermediate part (intermediate between the entrance side and the other side), and the drum diameter is gradually reduced from the intermediate part toward the other side (exit side). Thus, it is possible to increase the gap with the pile hole wall, reduce the kneading resistance of the drum, and increase the rotational speed of the drum. Also, when the rod is rotated in the reverse direction, the same kneading as in the normal rotation can be performed, and the pile hole wall is not damaged. That is, the kneading area (the area to be kneaded in contact with the pile hole wall) can be somewhat reduced to increase the kneading speed, so that the desired kneading amount and kneading speed can be adjusted appropriately. Kneading and piling holes can be created. Furthermore, in the case of a kneading method for controlling the amount of drilling fluid used in the ground containing soil having a high kneading resistance, this shape that can adjust the drum kneading area is particularly effective.
[0030]
[Example 1]
Of this invention Construction Examples will be described with reference to FIGS. In this invention, since the use or non-use of the drilling fluid is determined depending on whether or not the bearing capacity is expected, the soil strength (for example, N value) in the depth direction of the pile hole to be drilled during the drilling of the pile hole is confirmed during the drilling. There is a need to. The soil strength in the depth direction of the pile hole can be seen from the soil columnar figure by the standard penetration test, but this standard penetration test only depends on the site area of the building. . Therefore, even if 50 to 100 foundation piles are penetrated at the construction site (excavating the same number of pile holes), the standard penetration test may be only one place, for example. If you drill 50 pile holes, there are 50 ways. However, since it is a stratum, even if the thickness of the stratum and the depth from the ground surface are different, the tendency of the magnitude of the N value is almost equal, so measure the accumulated current value or the accumulated torque value proportional to the N value, The graph by the numerical value can be compared with the graph of the N value. Since this N value is proportional to the accumulated current value, in this embodiment, the accumulated current value between the ground layers at different depths is measured in one pile hole, and the relationship with the N value is obtained. I made a decision. For example, if the accumulated current value for every 50 cm when the N value is 10 in a sandy soil layer is 1000 A · S, liquidless excavation is performed at a depth indicating a value of 1000 A · S or less, and the value exceeds 1000 A · S. In this case, excavation using the excavation liquid as excavation auxiliary means is performed, and the best excavation of the pile hole at the site can be performed by controlling the predetermined discharge amount of the excavation liquid by a computer according to the magnitude of the numerical value. The N value in the above is proportional to the excavation power, but is proportional to the integrated current value because the voltage of the power source of the excavator is constant.
[0031]
In the above, the use or non-use of the drilling fluid is controlled by the integrated current value at a certain depth, so it can of course be dealt with immediately even if the soil strength of the formation changes frequently (for example, every 50 cm). The amount of drilling fluid discharged by the magnitude of the integrated current value can also be controlled (for example, when the integrated current value is large, a relatively large amount of drilling fluid is discharged).
[0032]
That is, during excavation of one pile hole, the accumulated current value required for excavation of 50 cm from 50 cm above the depth to the depth is continuously measured at that depth. Therefore, it is possible to reflect the soil strength in that range (the depth range of 50 cm. In the standard penetration test, the soil strength measured in the standard penetration test is accumulated and displayed corresponding to the depth range of the N value) in the excavation conditions. It is possible to control the amount of drilling fluid according to the soil strength on the ground directly below that area and control the excavation reflecting the ground strength in real time.
[0033]
Therefore, since excavation is carried out based on the integrated current value, which is a standard for ground strength, rather than excavation based on personal judgment based on experience, etc., excessive excavation fluid is suppressed and soil removal is reduced. A stable and reliable pile hole can be created.
[0034]
When excavation is completed as described above, while moving the excavating rod upward, the cement milk is poured into the excavated soil and stirred to produce soil cement. In this case, the final height of cement milk injection is regulated (the upper limit is the height at which the soil cement does not overflow when the concrete pile is inserted into the pile hole). To prevent the outflow.
[0035]
In other words, soil cement is filled in the gap between the hollow part of the concrete pile, the outer wall of the concrete pile, and the inner wall of the pile hole. In this case, the volume of the hollow part of the concrete pile and the inner wall of the pile hole Since the total volume of the gap between the outer wall of the concrete pile and the concrete pile can be easily calculated, if this total volume is divided by the cross section of the pile hole, the distance from the bottom of the pile hole to the upper limit liquid level of the soil cement can be calculated easily I can write.
[0036]
In the embodiment, a predetermined amount of drilling fluid discharge and cement milk discharge is set in advance corresponding to the integrated current value. During the excavation, the integrated current value during excavation, that is, the soil strength (N value) is set. ) The drilling fluid discharge timing and discharge amount, and the cement milk discharge timing and discharge amount are all controlled by the computer in real time while drilling, so that excavation can be performed under the best conditions and an appropriate amount of soil cement can be used. Can be generated (FIG. 1).
[0037]
[Example 2]
An embodiment of the present invention will be described with reference to FIGS. In the present invention, the excavation rod 1 having the stirring bar 4 and the kneading drum 5 fixed to the middle portion of the hollow rod 3 having the excavation head 2 fixed to the tip is lowered at predetermined intervals while rotating, and the pile hole 6 Drilling. In this case, every time the excavation rod 1 descends by a certain depth (for example, 50 cm), the accumulated current value required during that time is plotted in parallel with the N value graph, and the sandy soil layer has an N value of about 15 and viscous soil. Drilling without drilling fluid up to the position corresponding to the accumulated current value near the N value of 10 in the bed, drilling from around the accumulated current value exceeding the N value of 15 for the sandy soil layer and N value of 10 for the viscous soil layer Excavate by discharging liquid.
[0038]
In the above, when the formation at the position of the standard penetration test and the formation at the pile hole excavation position are substantially parallel, the N value graph and the integrated current value graph correspond to the horizontal direction by depth. The sandy soil layer is divided into an N value of less than 15, an N value of 15 or more, a viscous soil layer of an N value of less than 10 and an N value of 10 or more. FIG. 8 (a)).
[0039]
Next, when the stratum at the standard penetration test position and the stratum at the pile hole excavation position are shifted in the vertical direction (FIG. 8 (b)), the sandy soil layer has an N value of less than 15 and is a viscous soil layer. Excavation is performed without a drilling fluid only during a depth corresponding to an N value of less than 10, and drilling is performed using the drilling fluid for other depths (FIG. 8B).
[0040]
In the case of FIG. 8A, excavation is performed without drilling fluid up to 11 m from the ground surface, and drilling fluid is excavated as excavation aid for 11 m or more. On the other hand, in the case of FIG. 8 (b), drilling is performed without drilling fluid up to a depth of 5m from the ground surface, drilling is performed using a drilling fluid up to a depth of 5m to 8m, and up to a depth of 8m to 12m. Excavation is performed without drilling fluid, and the drilling fluid is drilled at a depth of 12 m or more. As described above, when the formation is parallel to the horizontal direction, the integrated current value increases or decreases with the same depth change as the N value. Therefore, the N depth value is controlled corresponding to the N value value. When the accumulated current value changes at a depth slightly shifted in the vertical direction, the discharge or stop of the drilling fluid is determined corresponding to the accumulated current value corresponding to the N value 15 or the N value 10. Therefore, at the site, the integrated current value almost corresponding to the N value 15 or N value 10 can be used as a guideline for determining whether or not to use the drilling fluid, or can be automatically operated if it is stored in advance in the computer. it can.
[0041]
In this embodiment, when the N value exceeds 15 or N value 10, it does not mean that drilling is not possible unless drilling fluid is used. If you decide to use it, you can drill a reasonable pile hole. In the case of collapsible soil, plotting the integrated current value by depth from the relationship with the N value by depth of the soil column diagram of the standard penetrating test (graphing it) makes it possible to accurately determine whether it is a collapsed formation or not. Since it can be determined, it is determined whether to discharge or stop the drilling fluid according to the above procedure.
[0042]
As described above, drilling is performed without drilling fluid as shown in FIG. 2 (a) (mostly holes 6a), and then drilling is performed using the drilling fluid as shown in FIG. 2 (b). After excavating the pile hole 6b and completing the excavation of the expanded hole 6c, the excavating rod 1 is pulled up as indicated by arrow 8 while discharging the cement milk as indicated by arrow 7 from the lower end of the excavating rod 1 ( FIG. 2 (c)). In this case, since the excavation rod 1 is rotated, the excavation soil 9 and the cement milk are mixed by the stirring bar 4 to generate the soil cement 11. In this case, the strength of the soil cement 11 is determined by the amount of cement milk per unit volume when the water-cement ratio is constant (for example, W / C 60%). For example, the amount of cement milk is increased in the expanded hole 6c ( For example, if the bottom hole diameter is 1.1m x height is 2.5m, 2.38m ³ ), The upper part reduces the amount of cement milk (for example, 0.0478 m per 1 m when the drilling diameter is 0.78 m) ³ ).
[0043]
Alternatively, cement milk having different solidification strengths can be used properly.
[0044]
The highest level of completion of the discharge of cement milk in the above is the A surface in FIG. The height of this A surface is calculated so that when the concrete pile 10 is inserted, the highest position B of the soil cement 11 is flush with the ground surface. The concrete pile 10 is a joint pile with a joint pile 10b having the same diameter as that of the cylindrical pile 10a (having a lower shaft portion and an upper shaft portion and having joint portions on both shaft portions) from above (FIG. 3). (B)).
[0045]
In addition, according to FIG. 4, a large-diameter cylindrical pile 10a is arranged at the upper part, a small-diameter cylindrical pile 10b is connected to the lower part, and a node pile of the same diameter (as a solidified pile with an annular projection) is provided at the lower part. ) 10c is connected and used. The selection of the pile type is determined solely by the required supporting force and the required bending moment. Therefore, the combination of pile types is also selected depending on the load to be supported and the desired bending moment.
[0046]
In the above description, the relationship between the pile hole excavation and the N value (integrated current value), the relationship between the soil cement, and the like have been described. Hereinafter, examples of excavation will be described. The kneading drum 5 used in the above embodiment is formed so that the cross-sectional area gradually increases from the lower end surface toward the upper end surface with respect to the longitudinal direction of the excavating rod 1, and gradually from the left side surface toward the right side surface. It is formed in a curved shape so that the cross-sectional area becomes large. Therefore, while narrowing the passage range of the excavated soil rising upward from below the kneading drum 5, the excavated soil entering from the left side surface of the kneading drum 5 when the excavating rod 1 is rotated forward is the right side surface. It is comprised so that the passage range may be narrowed as it goes to. Accordingly, the left side surface of the kneading drum 5 is not in contact with the circumferential excavation inner wall of the pile hole 6, and at least the right side surface is in contact with the excavation inner wall of the pile hole 6. At least one kneading drum 5 a formed in this way is attached to the excavation rod 1. It is most effective to position the kneading drum 5a so that it can be welded or removed directly above the excavation head, where the excavation soil is not crushed and agitated relatively well, that is, at the lower end of the excavation rod. With respect to the longitudinal direction of the excavation rod 1, the lowermost kneading drum 5a is used as the kneading drum 5a having the above-mentioned changing cross section, and the upper kneading drum 5 is a conventional kneading drum 5 having no changing cross section. It can also be.
[0047]
That is, when the kneading surface of the kneading drum 5a can be widely taken (when the vertical length of the kneading surface can be increased), the maximum outer diameter portion of the kneading surface (that is, the excavation diameter of the pile hole 6) The width in the horizontal direction of the portion having substantially the same dimension) can be narrowed, and the drum diameter on the entry side and the other side of the excavated soil can be reduced. In this case, it is possible to adjust the pressing resistance during kneading of the kneading drum 5a, and to adopt a cross-sectional shape that performs the same function during reverse rotation, thereby enabling efficient kneading. Further, it is particularly effective in the case of a construction method for controlling the amount of drilling fluid used in the ground containing soil having a high kneading resistance.
[0048]
In the kneading drum 5a, the rotation direction of the excavating rod 1 during forward rotation is based on the clockwise direction. However, if the counterclockwise rotation is forward rotation, the shapes of the right side surface and the left side surface of the kneading drum 5a are reversed. become. The excavation rod 1 having the excavation head 2 at the tip thus formed is set on the ground at the pile burying position. In this embodiment, the bottomed hole 6c is provided in the pile hole 6, but even a straight pile hole can be applied.
[0049]
Next, the excavation rod 1 is rotated forward to excavate the ground as it is without discharging excavation liquid such as water from the tip of the excavation head 2. Here, although various structures can be applied to the excavation head 2 to be used, in this embodiment, an excavation head 2 having two excavation arms 12 and a main body portion 2a is used. The excavation arm 12 expands to excavate the pile hole shaft, and when the excavation rod 1 rotates in the reverse direction, the excavation arm 12 expands into an expanded excavation state to excavate the expanded hole 6c.
[0050]
The construction ground is generally softer in the upper part of the ground. Therefore, drilling fluid should be discharged to the sandy soil layer with an N value of less than 15 and the viscous soil layer with an N value of less than 10. The excavated soil excavated by the excavating head enters from the gap with the pile hole wall on the left side of the kneading drum, and the kneading surface in the right side direction of the kneading drum along the forward rotation direction. It is kneaded into the pile hole wall while being crushed. As a result, a hollow pile hole in which only a little excavated soil remains in the pile hole is formed (FIG. 2A).
[0051]
In addition, when the sandy soil layer has an N value of 15 or more and the viscous soil layer has an N value of 10 or more, after drilling with the drilling fluid as described above, the drilling is continued and the support layer is reached. Then, the excavation rod is rotated in the reverse direction so that the excavation head is in an expanded excavation state to form a pile hole widening portion. After forming an expanded bottom portion (for example, a diameter of 1.1 m and a height of 2.5 m) of a predetermined shape, cement milk (solidification strength: 20 N / mm) as a root solid liquid with the excavation rod rotated in the reverse direction ² ) Is poured into the expanded bottom and stirred and mixed with the excavated soil left in the expanded bottom, and the soil cement (solidification strength 20 N / mm) is mixed. ² Above).
[0052]
After the formation of the soil cement layer in the expanded bottom, return the excavation rod to normal rotation, put the excavation head in the normal excavation state, and continue the excavation soil (including mud and mud) in the section of the pile hole shaft. Cement milk (solidification strength 20N / mm ² ), Agitated and mixed with excavated soil, and soil cement (solidification strength 1 N / mm) ² Degree).
[0053]
In the injection of the cement milk, since the injection result of the specified amount of cement milk at each depth can be discriminated by constructing it while displaying the injection amount for each depth by a computer or the like, it is desired to be uniform within the soil cement formation section. The soil cement can be formed.
[0054]
Although the concrete pile 10 was used in the said Example, conventionally well-known ready-made piles (PHC pile, PRC pile, SC pile, steel pipe pile, node, etc.) were required by the necessity of bearing capacity, pile bending strength, peripheral surface bearing capacity, etc. Can be used properly.
[0055]
In addition to the ready-made piles, there is a bag body at the lower end of the pile, a pile that inflates the bag body by injecting cement milk into the bag body, or a reinforcing steel basket attached to the lower end of the pile, and expanding in the expanded bottom part You can also apply what you want. In addition, as a solidified pile with protrusions, for example, a cylindrical pile having a lower shaft portion and an upper shaft portion formed larger in diameter than the lower shaft portion on a node pile is connected and buried, and is largely enlarged near the ground. It can also be set as the structure which can endure the horizontal force which acts (FIG. 4).
[0056]
As the ready-made pile is inserted into the pile hole as described above, the soil cement of the pile peripheral portion and the expanded bottom portion rises and fills the gap between the outer wall of the ready-made pile and the inner wall of the pile hole. At this time, if the tip of the pile hollow portion is open, the pile hollow portion is also filled with the rising soil cement. If the tip of the pile hollow portion is closed, it is not necessary to fill the pile hollow portion with the soil cement, so that the amount of cement milk to be injected can be further reduced. Which of the above is adopted is determined in relation to the support force at the site.
[0057]
In this way, the pile is continuously inserted, and the pile is expanded so that at least one projecting portion, a lower shaft portion of the lower pile, and a deformed portion of the upper shaft portion are positioned in the bottom portion of the pile hole. At this time, a predetermined interval (for example, 50 cm) is provided between the bottom surface of the pile hole widened portion and the lower end surface of the lower pile, and a predetermined interval is provided between the upper surface of the pile hole widened portion and the uppermost protrusion located in the widened portion. If an interval (for example, 50 cm) is provided, a load transmission range can be secured, so that a high vertical support force and a high pulling strength can be exhibited.
[0058]
For the construction of the enlarged bottom consolidation portion 16 of the pile hole 6, the amount of drilling fluid is controlled according to the soil strength in the formation by a wet method, and according to the soil ground strength according to the measured accumulated current value. Since cement milk can be supplied, a soil cement layer with higher solidification strength can be reliably formed.
[0059]
In particular, as shown in FIGS. 3B and 4, the two nodes 18 a and 18 b (at least one) of the lower pile 10 b are positioned in the bottom expanded portion 16 of the pile hole 6, and the other nodes 18 c are arranged. When positioned directly above the widened portion 16, although depending on various conditions, a vertical support force that is approximately twice as high as that of a conventional straight pile can be expressed.
[0060]
Therefore, since the structure with the pile hole widening portion root consolidation part 16 can express a high vertical support force, the shaft portion of the concrete pile 10 and the shaft portion of the pile hole 6 have little influence on the support force. Considering these conditions, various structures can be adopted depending on the purpose.
[0061]
For example, in the shaft portion of the pile hole 6, the gap between the outer diameter of the pile 10 and the inner diameter of the pile hole can be made large, and excavation soil can be stored in the gap. it can. In addition, according to the soil strength of the formation, excavation can be performed by using either wet or dry type (with or without drilling fluid), so that the amount of drilling fluid used can be reduced, and the soil can be further reduced. In addition, coupled with the kneading of the pile hole wall, there is an effect of further ensuring the stability of the pile hole quality.
[0062]
[Example 3]
An embodiment of the apparatus of the present invention will be described with reference to FIGS. In the present invention, stirring bars 4 and 4 are radially arranged in a hollow rod 3 at a predetermined interval (for example, 1 m), and kneading drums 5 and 5a are fixed at a predetermined interval to the lower end of the hollow rod 3. The excavation head 2 is connected to constitute an excavation rod 1 (excavation apparatus) of the present invention.
[0063]
The kneading drum 5a has a planar arc shape, and has two side square kneading blades 15 and 15 fixed to the rod 3 by brackets 14 and 14, respectively. As shown in FIG. 7A, the kneading blades 15 and 15 have a trapezoidal shape in which the left side 15a is wide on the top and the bottom is narrow, the kneading surface 15b is substantially rectangular, and the right side 15c is vertically long. is there.
[0064]
In addition, as shown in FIG. 6, the kneading blade 15 has a wide gap with the wall of the pile hole 6 on the side where the kneaded excavation soil enters (that is, the left side surface 15a) and kneads to a predetermined pile hole diameter. A gap with the pile hole 6 wall on the side (that is, the right side surface 15c) is formed small.
[0065]
In another embodiment, as shown in FIG. 7 (b), the left side is a trapezoid with the top wide and the bottom narrow, the kneading surface 15b is rhombus (both top and bottom are inclined), and the right side 15c is a vertically long rectangle. It is. In still another embodiment, as shown in FIG. 7C, the left side is a trapezoid with the top wide and the bottom narrow, the kneading surface 15b is a trapezoid with the top inclined, and the right side 15c is a vertically long rectangle. .
[0066]
The kneading drum 5 is formed so that the cross-sectional area gradually increases from the lower end surface toward the upper end surface with respect to the longitudinal direction of the excavating rod 1, and the cross-sectional area gradually increases from the left side surface toward the right side surface. It is formed to be large.
[0067]
The kneading surface of the kneading drum 5 is formed so that the gap with the pile hole wall decreases from the lower end surface to the upper end surface of the kneading drum 5, and the kneading drum 5 has the kneading surface from the left side to the right side. The gap between the attaching surface and the pile hole wall is formed to be small. As the shape of the kneading surface of the kneading drum 5a, various shapes such as a rectangular front view, a parallelogram, and a trapezoid can be selected (FIGS. 7A, 7B, and 7C). In other words, any shape that allows easy entry of excavated soil and can form a desired pile hole diameter may be used. The kneading drum is formed of a steel plate in terms of strength, but other materials may be used as long as they have a predetermined strength. At least one kneading drum formed in this way is attached above the excavation head at the lower end of the excavation rod.
[0068]
In this embodiment, the rotation direction of the excavating rod during forward rotation is based on the clockwise direction. However, if the counterclockwise rotation is forward rotation, the shapes of the left side surface and the right side surface are reversed.
[0069]
In order to excavate a pile hole using the excavation rod, the excavation head 2 excavates the ground by rotating the excavation rod forward (clockwise). The excavated soil generated at this time enters from the left side of the kneading drum 5a. Since the kneading surface is formed so as to gradually approach a desired pile hole diameter from the left side surface toward the right side surface, the invaded excavated soil is kneaded to the pile hole wall so as to be crushed. Accordingly, the excavated soil can be directly kneaded to the pile hole wall without using the drilling fluid, and the pile hole wall of the pile hole shaft portion can be formed firmly. Moreover, even when a drilling fluid is used, mud produced by excavation can be kneaded to the pile hole wall in the same manner as described above.
[0070]
According to the embodiment, since the kneading drum 5a is used, the excavated soil can be more effectively kneaded into the pile hole. Therefore, the amount of excavated soil can be significantly reduced and the pile hole wall can be strengthened.
[0071]
Moreover, in the said Example, when widening the kneading | wing blade 15 shown in FIG. 6 and performing efficient kneading, in FIG.6 (c), the outer diameter of the kneading surface 15b is made into a pile hole, for example. The outer diameter of the right side surface 15c is set to a small diameter that is substantially the same as the outer diameter of the left side surface 15a, and between the left side surface 15a and the kneading surface 15b and between the kneading surface 15b and the right side surface. It is also possible to change the shape of the kneading surface between 15c to a gently inclined surface. Here, in the kneading blade 15, efficient and economical kneading is achieved by increasing or decreasing the ratio between the excavation dimension width portion of the kneading surface 15 b and the width of the other portion (the portion other than the kneading surface 15 b). Excavation work is possible.
[0072]
[Example 4]
9 to 12 show other inventions. Construction An example will be described. Each Construction example or In the embodiment, a method of burying a ready-made pile after excavating a pile hole has been described. The so-called medium excavation method will be described.
[0073]
1. Configuration of drilling rod
[0074]
The excavation rod 1 has a configuration in which an excavation head 2 is connected to a lower end portion of a rod 3 provided with a spiral 30 on the outer periphery (FIG. 11).
[0075]
The excavation head 2 includes a head main body 2a connected to the rod 3 and two excavation arms 12 and 12 attached to the head main body 2a so as to be swingable. The excavation arm 12 has an excavation blade at the tip, and has a structure in which the outer diameter can be varied in three stages. That is, as a first stage, a neutral state at the time of insertion into the pile hollow portion (FIG. 9A), and as a second stage, a normal excavation state in which the rod 3 is rotated forward to excavate the shaft portion 17 of the pile hole 6 ( As shown in FIG. 9 (b)), as a third stage, the rod 3 is reversely rotated so as to be variable in a bottomed excavation state (FIG. 9 (c)) in which the bottom expanded portion 16 of the pile hole 6 is excavated. The “neutral state” in the above means a state in which the excavation arm 12 hangs downward.
[0076]
Further, a kneading rod 19 is connected to the excavating arm 12 so that the excavated pile hole wall can be leveled while excavating the shaft portion 17 of the pile hole 6 in the second stage. In the second stage, the kneading bar 19 has the kneading part 20 arranged vertically along the pile hole wall, and can level the pile hole wall over the entire length of the kneading part 20 (FIG. 9B). ). That is, the leveling of the pile hole wall is controlled simply by the rotation of the rod 3 and is integrated with the operation of the rod 3.
[0077]
In this state, the kneading part 20 of the kneading bar 19 is the same as in the third embodiment, in the cross section of the kneading part 20, and the pile hole wall on the side where the excavated soil to be kneaded enters (that is, the left side 20a). The gap with the pile hole wall is made smaller toward the other side (namely, the right side surface 20c) kneaded to a predetermined pile hole diameter (FIG. 10). Also, if the kneading surface 20b is kneaded with the same diameter as the drilling diameter, the other side 20c is reduced in diameter to widen the gap with the pile hole wall, and the kneading resistance is adjusted, the efficiency corresponding to various soil properties and strength can be achieved. Kneading is possible.
[0078]
Further, the head body 2a is formed with a discharge port (side surface portion of the head body) 21, a discharge port (lower end portion of the head body) 22 and the like for cement milk, etc., and the discharge ports 21 and 22 supply water in the rod. It communicates with a pipe (not shown). Further, fixed excavation blades 23, 23 project downward from the lower end of the head body 2a.
[0079]
2. Configuration of concrete pile 10
[0080]
The concrete pile 10 used in this embodiment is composed of a lower pile 10b having a node (annular rib) formed at the lower end, and a straight upper pile 10a connected to the upper side of the lower pile 10b (see FIG. 12 (a)).
[0081]
The lower pile 10b has a predetermined outer diameter D ₁ 2 node portions (outer diameter D) ₃ ) 18b and 18c are formed, and the outer diameter D is continuous with the upper node 18b. ₂ The upper shaft portion 25 is continuously provided. A node portion 18 a is also formed in the upper shaft portion 25. The node portions 18a, 18b, and 18c are arranged at substantially equal intervals (100 cm) in the vertical direction.
[0082]
Further, “the outer diameter D of the node 18” ₃ >>"Outer diameter D of upper shaft portion 25" ₂ >>"Outer diameter D of lower shaft portion 24" ₁ (Fig. 12 (a)). Further, the upper pile 8 has the same outer diameter D as the outer diameter of the upper shaft portion 5 of the lower pile 2. ₂ It can be connected with the lower pile 2 (FIG. 12A). For example, D ₁ , D ₂ , D ₃ Are formed with dimensions of 60 cm, 70 cm and 75 cm, respectively.
[0083]
3. Method of burying concrete pile 10
[0084]
(1) The excavation head 2 is attached to the tip of the rod 3, and the rod 3 is inserted through the hollow portion of the lower pile (pile with projection) 10b. Next, the lower pile 10b through which the rod 3 is inserted with a crane or the like is carried to the pile burying point and attached to the pile driving machine. In the mounting work, the rod 3 is connected to the earth auger attached to the pile driving machine, and the pile supporting device attached to the upper pile end plate of the pile with protrusions is gripped by the pile supporting device at the lower part of the soil hopper ( Not shown).
[0085]
(2) Next, the rod 3 is rotated in the forward direction (clockwise), and air is discharged from the discharge port (tip) 22 of the excavation head 2 while the air is mixed with the excavation soil. While excavating the soil into the earth discharge hopper, the pile hole shaft is excavated.
[0086]
Here, selection of whether to discharge air from the discharge port 22 or to discharge the drilling fluid is performed based on a preset numerical value of the integrated current value measured during excavation, as in the first embodiment. That is, when the integrated current value is smaller than a preset value, air is discharged, and when it is larger, the drilling fluid is discharged.
[0087]
Further, every time the excavation head 2 excavates a predetermined section, the excavation soil mixed with excavation soil or drilling fluid is sufficiently mixed and agitated and kneaded with the excavation head 2, and then the pile is pushed in. In the lower layer, stirring and mixing and kneading are sequentially performed in the same manner.
[0088]
At this time, the excavation diameter is the protrusion diameter D of the lower pile 10b. ₃ Or slightly larger diameter D ₁₁ Excavate with. In this way, the lower pile (pile with protrusion) 10b is inserted while excavating (FIG. 11A).
[0089]
(3) At the stage where the lower pile 10b is lowered to a predetermined depth (a state where the upper end protrudes above the ground), the lower pile 10b is held, and the rod 3 is inserted into the upper end of the lower pile 10b in the same manner as the lower pile 10b. Connected upper piles 10a.
[0090]
(4) Next, after excavating at a predetermined depth, with the lower pile 10b (pile with protrusions) held at that height, the drilling fluid was discharged from the discharge port 22 and attached to the excavation arm 12 of the excavation head 2 While kneading the excavated soil to the pile hole wall with the kneading rods 19, 19, the rod (excavation head 2) 3 is repeatedly raised and lowered while leveling the pile hole wall, and the shaft portion 17 of the pile hole 6 is further excavated (FIG. 11). (B)).
[0091]
At this time, the kneading part 20 of the kneading rod 19 has a cross section of the kneading part 20 and widens the gap with the pile hole wall on the side where the excavating soil to be kneaded enters (that is, the left side surface 20a), Since the gap with the pile hole wall is formed small toward the other side (namely, the right side surface 20c) to be kneaded to the pile hole diameter (FIG. 10), efficient kneading can be performed.
[0092]
Moreover, the predetermined depth in the above is the uppermost position of the section which inject | pours a pile periphery fixing liquid from the pile hole bottom-up part 16a upper end.
[0093]
(5) Next, after forming the shaft portion 17 of the pile hole 6 to the vicinity of the support layer (shown by the chain line 17a in FIG. 11), the rod 3 is rotated in the reverse direction (counterclockwise) to bring the excavation head 2 into an expanded excavation state. In addition, the lower end portion (17a) of the pile hole shaft portion 17 is enlarged and the lower portion of the excavated shaft portion 17a is enlarged to the pile hole bottom 16a to form the pile hole enlarged bottom portion 16 (FIG. 11 (b), the chain line shown in FIG. 16a). At this time, excavation is performed with the diameter of the pile hole shaft portion 17 to a predetermined position of the support layer (near the hole bottom 16a of the pile hole to be formed), and then the rod 3 is rotated in the reverse direction so that the pile hole shaft portion 17 The lower end portion can be enlarged to form the pile hole enlarged bottom portion 16 (not shown).
[0094]
(6) After completing excavation of a predetermined pile hole widening portion (length: 250 cm, outer diameter: 110 cm) 16, a root-setting liquid (with a predetermined solidification strength) from the discharge port 22 of the excavation head 2 into the pile hole widening portion 16. Cement milk) is injected and mixed with the gravel remaining in the pile hole widening portion 16 to form a soil cement layer (root-solidified portion) in the pile hole widening portion 16 (FIG. 11C). At this time, the amount of cement milk to be injected can be set to the optimum amount of cement milk corresponding to the ground strength by the integrated current value measured during excavation.
[0095]
At this time, as a method for forming the soil cement layer, in order to form a high-quality soil cement layer with little quality variation, it is desirable to do the following.
[0096]
That is, after completion of excavation of the pile hole, all cement is supplied from the discharge port 22 at the lower end of the excavation head 2 while stirring the excavation head 2 while holding the excavation head 2 at the lowermost part of the pile hole widening portion 16 (near the hole bottom 16a). Dispense approximately 1/3 of the milk milk. Subsequently, one third of the total amount of cement milk is discharged while raising the rod 3 to the vicinity of the upper end 16b of the pile hole widening portion 16 while stirring with the excavation head 2. Next, while raising and lowering the excavation head 2 a plurality of times within the pile hole bottom portion 16, one third of the remaining cement milk is discharged, stirring and mixing are performed, the rod 3 is pulled up, and the inside of the pile hole bottom portion 16 is A soil cement layer is formed on the substrate (first method).
[0097]
In addition, another desirable method for injecting cement milk (second method) is as follows. First, the discharge port 22 of the excavation head 2 is installed at approximately the center of the lowest position (near the hole bottom 16a) of the pile hole widening portion 16, While stirring and discharging cement milk from the discharge port 22, the inside of the pile hole widened portion 16 is reciprocated two times up and down to complete the injection at the upper end 16 ba of the pile hole widened portion 16.
[0098]
As another desirable method for injecting cement milk (third method), cement milk is injected from the discharge port 22 of the excavation head 2 at the lowest position (near the hole bottom 16a) of the pile hole widening portion 16 to pile. It is also possible to push up the excavated mud in the hole expanded bottom portion 16 and replace the injected cement milk to form a cement milk layer.
[0099]
(7) After forming a soil cement layer (or cement milk layer) in the pile hole widening portion 16, the rod 3 is rotated forward to return the excavation head 2 to the normal excavation state, and the pile circumference fixing liquid of the pile hole shaft portion 17. A pile periphery fixing liquid (cement milk) having a predetermined solidification strength is discharged and injected into the injection section from the discharge port 22 of the excavation head 2, and stirred and mixed with the excavation mud to form a pile periphery fixed liquid layer (soil cement).
[0100]
At this time, the pile circumference fixing liquid to be filled is pushed up by the concrete pile 11 when the concrete pile 10 (upper pile 10a, lower pile 10b) is completely set in the pile hole 6 and the pile pile filling (soil cement or the like) is pushed up. In such a state, the amount that the pile periphery fixing liquid is filled to the vicinity of the pile head after installation is injected.
[0101]
Here, the part (lower pile 2 upper shaft part 5 and upper pile 8) located in the pile hole shaft part 17 is a node part outer diameter D. ₃ Smaller outer diameter D ₂ Therefore, the pile fixing liquid is likely to rise in the gap between the pile hole wall and the concrete pile 10.
[0102]
In addition, the shaft diameter of the lower pile 10b and the outer side of the upper pile 10a are used so that the pile periphery fixing liquid can easily rise by utilizing the gap between the concrete pile 10 located at the pile hole shaft portion 17 and the pile hole wall. This gap can be adjusted by appropriately selecting the diameter.
[0103]
In addition, in the pile hole shaft portion 17, the shape and size of the pile periphery fixing liquid is likely to rise, or the shape of the concrete pile 10 positioned in the pile hole shaft portion 17 when a tremy pipe or the like is used after the concrete pile 10 is embedded.・ Any size is not required (not shown).
[0104]
(8) After that, the excavation head 2 is set to the neutral state, and the rod 3 and the excavation head 2 are accommodated in the hollow portions 26 and 26 of the concrete pile 10 that has been held at a predetermined depth without giving rotation to the rod 3. . The concrete pile 10 is pressurized and sunk to a depth where the two node portions 18b and 18c of the lower pile 10b are accommodated in the pile hole widened portion 16 (FIG. 11 (e)). Here, two of the node portions 18 are accommodated in the pile hole widened portion 16, but usually at least one node portion 18 is positioned in the pile hole widened portion 16.
[0105]
Moreover, by the sedimentation of the concrete pile 10, the soil cement pushed up from the soil cement layer and the pile periphery fixing liquid layer overflows from the upper end of the hollow portion 27 of the upper pile 10a of the concrete pile 10, and the concrete pile 10 outer wall and the pile hole wall Cement milk also rises from the gap. Thereby, it can be confirmed that the cement milk is filled in the gap between the outer wall of the concrete pile 10 and the outer wall of the pile hole wall.
[0106]
(9) After the concrete pile 10 is completely buried, the excavation rod 1 (excavation head 2) is pulled up to complete the construction. After the cement milk solidifies, the foundation pile structure is completed (FIG. 12 (b)). At this time, a layer 29 in which cement milk is solidified is formed between the lower end 28 of the lower pile 10b and the pile hole bottom 16a (FIG. 12B).
[0107]
(10) Compared to the so-called pre-digging method as in Examples 1 to 3, in the middle digging method as in this example, the specific gravity of kneading in the entire pile structure is not so high, but in this example Thus, a foundation pile structure with higher quality can be constructed by reliably kneading. Generally, it was necessary to set the excavation conditions in the medium excavation method with a margin with respect to the geology, but according to the present invention, efficient and fine excavation kneading corresponding to the soil strength at each depth can be performed.
[0108]
Therefore, when excavating, pile hole excavation work corresponding to the geology at every depth, that is, soil strength, can be performed in real time, so there is a mixture of strata that are easy to collapse overall and whose bearing capacity cannot be expected very much. Even if it is the ground, it is possible to construct the medium digging method under stable and reliable construction conditions by using dry or wet methods together.
[0109]
In particular, when the joint part of a concrete pile with a node at the lower end is embedded in a pile hole enlarged root-filled part filled with soil cement with high solidification strength, the shear force on the upper and lower surfaces of the joint part is reduced. Propagation is observed, and shear supporting force can be developed. Therefore, the foundation pile which expects a high bearing capacity can be implemented by the medium excavation method. In addition, if a soil cement layer is formed between the lower end of the concrete pile and the bottom of the expanded portion, the shear force can be propagated from the lower end surface of the concrete pile, and a foundation pile having a higher bearing capacity can be realized.
[0110]
In other words, while pushing in concrete piles, excavating each layer sequentially, measuring the accumulated current value corresponding to the depth, and controlling the injection amount of drilling fluid, cement milk etc. according to the magnitude of the accumulated current value A pile hole and a foundation pile structure filled with soil cement of desired quality and solidification strength can be configured. In addition, even in strata where bearing capacity cannot be expected, pile holes are excavated while pushing a concrete pile with a node at the lower end, so before the sediment of the pile hole wall of the strata collapses to the bottom of the pile hole, It can be pressed with a joint. Moreover, since the amount of drilling fluid can be controlled according to the soil strength at each depth, it is possible to realize a medium excavation method that can reduce the amount of soil removal and provide a high-quality and stable foundation pile structure.
[0111]
【The invention's effect】
According to the present invention, drilling is performed by deciding whether or not to use the drilling fluid depending on whether or not the bearing capacity is expected, so that the pile hole can be drilled easily and quickly with relatively small electric power, and the amount of muddy water discharged There is an effect that can be significantly reduced. Therefore, the construction environment can be improved and the costs, time and labor related to muddy water treatment can be significantly reduced.
[0112]
According to the apparatus of the present invention, the excavated soil can be kneaded to the pile hole wall as much as possible and efficiently, so that the amount of discharged muddy water can be reduced and the pile hole wall is further strengthened. As a result, the bearing capacity can be improved and the quality of the entire foundation structure can be improved.
[0113]
Furthermore, there are various effects such as the construction of a rational foundation pile structure more suitable for the soil quality can be achieved by automatic control of the injection amount of cement milk and automatic control of the drilling fluid.
[Brief description of the drawings]
FIG. 1 of the present invention Construction Example block diagram.
FIG. 2A is a conceptual diagram of an excavation example in which no drilling fluid is used.
(B) The conceptual diagram of the excavation example which uses a drilling liquid similarly.
(C) The conceptual diagram at the time of making soil cement similarly.
[Fig. 3] (a) A conceptual view of the finished soil cement.
(B) The conceptual diagram of the Example which similarly inserted the pile.
FIG. 4 is a conceptual diagram of another embodiment in which a pile is also inserted.
FIG. 5 is a conceptual diagram of the embodiment before the excavation rod is taken out when the pile hole excavation is completed.
FIG. 6 (a) This The enlarged top view which cut | disconnected a part of Example of the kneading drum of invention of this invention.
(B) The enlarged front view of the attachment state which abbreviate | omitted one part.
(C) The enlarged bottom view which cut a part similarly.
FIG. 7A is an enlarged end view of one blade that also constitutes a kneading drum.
(B) Enlarged end view of another embodiment.
(C) Enlarged end view of another embodiment.
FIG. 8 (a) In the construction example of this invention, Graph of N value, power value and depth.
(B) The graph of another Example similarly.
FIGS. 9 (a) to 9 (c) show a fourth embodiment of the present invention. (Example of construction) The front view showing the three states of the excavation head used for a.
FIG. 10 is an enlarged cross-sectional view of a kneading part in Example 4 as well.
FIGS. 11A to 11E are longitudinal sectional views showing a construction process of Example 4. FIGS.
12A is a longitudinal sectional view of a concrete pile used in Example 4. FIG.
(B) Foundation pile structure constructed in Example 4.
[Explanation of symbols]
1 Drilling rod
2 Drilling head
3 Rod
4 Stir bar
5 Kneading drum
6 Pile hole
9 Excavated soil
10 Concrete pile
11 Soil cement
12 Excavating arm
16 Expanded bottom of pile hole
17 Shaft hole shaft
18 Pile node
19 Kneading stick
20 Kneading part

Claims (2)

  A drilling rod that connects a drilling head having a drilling blade at the tip and has a kneading drum that abuts against the pile hole wall, and is drilled while rotating, wherein the kneading drum enters at least the kneading soil to be kneaded Widen the gap with the pile hole wall on the side to be made, and form a small gap with the pile hole wall toward the other side kneaded to a predetermined pile hole diameter, and the kneading drum has a longitudinal direction of the excavation rod On the other hand, an outer wall surface is formed so that a gap with the pile hole wall decreases from the lower end surface toward the upper end surface, and the cross-sectional area gradually increases. Kneading equipment.   An excavation rod having an excavation blade connected to a tip and excavating while rotating, a kneading drum is fixed at predetermined intervals, and at least one of the kneading drums is arranged in a longitudinal direction of the excavation rod. On the other hand, a kneading drum having an outer wall surface formed so that the cross-sectional area gradually increases from the left side surface to the right side surface, and the kneading drum extends from the lower end surface to the upper end surface with respect to the longitudinal direction of the excavation rod. The pile wall wall kneading apparatus is characterized in that the outer wall surface is formed so that the gap with the pile hole wall becomes smaller and the cross-sectional area gradually increases.

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