WO2022149421A1 - 杭、杭の施工方法、構造物、構造物の構築方法、杭の設計方法及び杭の製造方法 - Google Patents
杭、杭の施工方法、構造物、構造物の構築方法、杭の設計方法及び杭の製造方法 Download PDFInfo
- Publication number
- WO2022149421A1 WO2022149421A1 PCT/JP2021/046069 JP2021046069W WO2022149421A1 WO 2022149421 A1 WO2022149421 A1 WO 2022149421A1 JP 2021046069 W JP2021046069 W JP 2021046069W WO 2022149421 A1 WO2022149421 A1 WO 2022149421A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pile
- fin
- fins
- pile body
- pull
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims description 50
- 238000004519 manufacturing process Methods 0.000 title claims description 13
- 230000002093 peripheral effect Effects 0.000 claims description 21
- 230000000149 penetrating effect Effects 0.000 claims description 6
- 238000010276 construction Methods 0.000 description 50
- 229910000831 Steel Inorganic materials 0.000 description 28
- 239000010959 steel Substances 0.000 description 28
- 230000035515 penetration Effects 0.000 description 21
- 230000000694 effects Effects 0.000 description 16
- 238000010586 diagram Methods 0.000 description 8
- 239000004568 cement Substances 0.000 description 4
- 239000008267 milk Substances 0.000 description 4
- 210000004080 milk Anatomy 0.000 description 4
- 235000013336 milk Nutrition 0.000 description 4
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 239000000470 constituent Substances 0.000 description 2
- 230000001747 exhibiting effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000003892 spreading Methods 0.000 description 2
- 238000012795 verification Methods 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 238000009430 construction management Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000009415 formwork Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000001141 propulsive effect Effects 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/22—Piles
- E02D5/54—Piles with prefabricated supports or anchoring parts; Anchoring piles
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/22—Piles
- E02D5/56—Screw piles
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D2200/00—Geometrical or physical properties
- E02D2200/16—Shapes
- E02D2200/1671—Shapes helical or spiral
Definitions
- the present invention relates to piles, pile construction methods, structures, structure construction methods, pile design methods, and pile manufacturing methods.
- Steel pipe piles are commonly used in harbor structures. High pull-out bearing capacity is required for steel pipe piles depending on the structure and ground conditions such as piers and quay piles.
- As a construction method for increasing the pull-out bearing capacity there is a rotary pile construction method in which a wing is attached to the tip of a steel pipe pile.
- the driving pile method using a striking hammer, a vibro hammer, etc. is the mainstream, and the rotary pile method, which requires a relatively large rotary construction machine, is not applied.
- piles that can be constructed by the driving pile method and press-fitting method, which are the mainstream in the harbor field, without using water jets or cement milk injection, and can demonstrate high pull-out bearing capacity have been proposed.
- a steel pipe pile (see Patent Document 1) in which a plurality of spiral ribs forming spirals are formed on the outer peripheral surface on the lower side of the steel pipe, or a plate-shaped protrusion is fixed along the axial direction of a steel pipe pile body.
- Patent Document 2 A steel pipe pile (see Patent Document 2) has been proposed.
- the steel pipe pile described in Patent Document 1 enhances the pull-out support force by the peripheral frictional force of the spiral rib.
- the steel pipe pile described in Patent Document 1 is not economical because it is necessary to form spiral ribs on the outer peripheral surface of the steel pipe so as to form a spiral.
- the steel pipe pile described in Patent Document 2 enhances the pull-out supporting force by the peripheral frictional force and the supporting pressure of the plate-shaped protrusion.
- the steel pipe pile described in Patent Document 2 is not economical because it is costly from the viewpoint of material cost and processing cost because it is necessary to form a relatively large protrusion in order to increase the peripheral friction force. ..
- the present invention has been made in view of the above problems, and an object of the present invention is that it does not require large-scale equipment for construction, is excellent in economy and environment, and has little penetration into the support layer.
- two or more plate-shaped fins are arranged on the outer peripheral surface of the pile body at the lower end of the pile body, and each fin has a vertical length of the pile body.
- the outer diameter is 0.5 times or more and 1.75 times or less, and the inclination angle is 0 degrees or more and 45 degrees or less with respect to the central axis of the pile body.
- the method for constructing a pile according to the present invention is to penetrate the pile according to the present invention into the ground where the support layer exists, and the upper end of the fins arranged on the pile is located in the support layer. Penetrate like.
- the structure according to the present invention includes a pile according to the present invention.
- the method for constructing a structure according to the present invention includes a step of penetrating a pile according to the present invention into the ground.
- the pile design method according to the present invention is the pile design method according to the present invention, in which the inclination angle is set based on the pull-out support force and the push-in support force required for the pile, and then the vertical direction is set.
- the lower limit of the length is set according to the pull-out support force and the push-in support force.
- the method for designing a pile according to the present invention is to design a pile in which two or more plate-shaped fins are arranged on the outer peripheral surface of the pile body at the lower end of the pile body, and each of the fins is
- the vertical length is set to be 0.5 times or more and 1.75 times or less of the outer diameter of the pile body, and the inclination angle is set to be 0 degrees or more and 45 degrees or less with respect to the central axis of the pile body.
- the method for manufacturing a pile according to the present invention is to manufacture a pile in which two or more plate-shaped fins are arranged on the outer peripheral surface of the pile body at the lower end of the pile body, and each of the fins is The vertical length is 0.5 times or more and 1.75 times or less the outer diameter of the pile body, and the inclination angle is 0 degrees or more and 45 degrees or less with respect to the central axis of the pile body.
- the method of constructing the pile, the structure, the method of constructing the structure, the method of designing the pile, and the method of manufacturing the pile according to the present invention large-scale equipment is not required for the construction, and the construction is excellent in terms of economy and environment. Furthermore, even under the condition that there is little penetration into the support layer, high pull-out support force and high push-in support force can be exhibited, and the occurrence of construction troubles can be suppressed.
- FIG. 1 is a conceptual diagram illustrating a pile according to an embodiment of the present invention, in which (a) is a case where the fins are attached substantially parallel to the central axis of the pile body, and (b) is a fin. Indicates that the pile is mounted at an angle with respect to the central axis of the pile body.
- FIG. 2 is a conceptual diagram illustrating a pull-out bearing force exerting behavior when a pull-out load is applied to a pile according to an embodiment of the present invention.
- FIG. 3 is a diagram showing the relationship between the penetration position of the lower end portion of the pile and the support layer according to the embodiment of the present invention.
- FIG. 4 is a construction conceptual diagram in the case where the pile according to the embodiment of the present invention is rotationally penetrated by a vertical load.
- FIG. 5 is a conceptual diagram showing the force acting on the fins when the pile according to the embodiment of the present invention is rotationally penetrated by a vertical load.
- FIG. 6 is a diagram showing a three-dimensional FEM model used for verification of the pull-out bearing capacity of the pile in the embodiment.
- FIG. 7 is a graph showing the relationship between the load and the withdrawal amount calculated by analysis for a pile having fins attached parallel to the central axis of the pile body.
- FIG. 8 is a graph showing the relationship between the loading load and the withdrawal amount calculated by analysis for a pile to which fins are attached by inclining with respect to the central axis of the pile body.
- the pile 1 has two or more plate-shaped fins 5 arranged on the outer peripheral surface of the pile body 3 at the lower end of the pile body 3.
- Each fin 5 has a vertical length lfv of 0.5 times or more and 1.75 times or less of the outer diameter D of the pile body 3, and an inclination angle ⁇ (see FIG. 1 (b)) of 0 degrees or more and 45 degrees with respect to the central axis of the pile body 3. It is as follows.
- FIG. 1A shows a case where the fin 5 is attached substantially parallel to the central axis of the pile body 3
- FIG. 1B shows a case where the fin 5 is attached to the central axis of the pile body 3.
- substantially parallel means that the angle of the pile body 3 with respect to the central axis is 0 degrees or more and less than 1 degree.
- the distance between the adjacent fins 5 is 1/16 or more of the outer peripheral length of the pile main body 3, and the distance between the adjacent fins 5 is the outer circumference of the pile main body 3, if necessary. 1/2 or less of the length, the lower end position of the fin 5 is 50 mm or less from the lower end of the pile body 3, the upper end position of the fin 5 is from the lower end of the pile body 3 to twice or less the outer diameter D of the pile body 3, and the fin width wf is Satisfy one or more of the conditions that the fin plate thickness tf is twice or more, or the fin width wf is 1/2 or less of the outer diameter D of the pile body 3.
- lt indicates the distance (50 mm or less) from the lower end of the pile body 3 to the lower end of the fin 5.
- ⁇ indicates the tip angle of the fin 5.
- the tip angle ⁇ of the fin 5 is a predetermined angle determined by the relationship between the workability and the bearing capacity required for the pile 1.
- the tip angle ⁇ is preferably 60 degrees or less from the effect of reducing the shearing force received by the fin weld due to the bearing resistance of the thick fin plate when the pile is penetrated.
- the fin length lf is the distance when the lower end and the upper end of the fin 5 on the mounting side of the pile body 3 are connected by a straight line
- the fin horizontal length lf is the length of the lower end and the upper end of the fin 5 in the direction perpendicular to the central axis of the pile body 3. In each case, the determination is made based on the thickness center of the fin 5.
- FIG. 2 shows a conceptual diagram of the pull-out bearing force exerting behavior when a pull-out load acts on the pile 1 shown in FIG. 1 (a).
- the pull-out support force exerting ground 13 shows the ground that resists to exert the pull-out support force when the pile 1 is pulled out.
- the ground 13 exhibiting pull-out bearing capacity spreads near the upper end of the fin due to the effect of the internal friction angle of the ground, and the effect of spreading diminishes when a certain distance is left, forming a cylindrical slip surface.
- the spreading effect due to the internal friction angle of the ground increases as the ground becomes stronger.
- the pull-out support force increases as the range of the pull-out support force exerting ground 13 that resists when the pile 1 is pulled out is wide. Therefore, compared to the spiral rib used for the steel pipe pile disclosed in Patent Document 1 described above, the pull-out bearing capacity is increased by using the fin 5 having a large radial protrusion amount of the pile 1 from the surface of the pile body 3.
- the exerted ground 13 becomes a wide range, and a high effect can be exhibited.
- the presence of the fin 5 not only enhances the pull-out support force, but also increases the push-in support force exerting ground (not shown) near the lower end of the fin 5 due to the effect of the internal friction angle of the ground even when the pile 1 is pushed in. As it expands, it also improves push-in support.
- the number of fins 5 is two or more. As shown in FIG. 2 described above, the pull-out bearing capacity of the pile 1 is exerted by the resistance of the ground 13 that exerts the pull-out support force. As the number of fins 5 increases, the force transmitted from the fins 5 to the ground increases, the effect of the internal friction angle of the ground on the ground 13 exerting the pull-out support force near the upper end of the fins increases, and the pull-out support force increases.
- the presence of the fin 5 not only enhances the pull-out support force, but also increases the push-in support force exerted by the effect of the internal friction angle of the ground near the lower end of the fin 5 even when the pile 1 is pushed in, so that the push-in support force is exerted.
- the power also improves.
- the presence of the fins 5 (that is, one or more fins 5) not only enhances the pull-out support force but also improves the push-in support force. This is because, as described above, even when the pile 1 is pushed in, the ground that exerts the pushing bearing capacity expands near the lower end of the fin 5 due to the effect of the internal friction angle of the ground.
- the number of fins 5 is determined by the workability required for the pile 1, the pull-out support force, and the push-in support force. Further, in the present embodiment, in order to allow the pile 1 to penetrate stably in the axial direction, the number of piles 1 is two or more.
- the vertical length lfv is 0.5 times or more and 1.75 times or less with respect to the outer diameter D of the pile body 3 (see FIG. 1).
- the vertical length lfv is the distance between the lower end and the upper end of the fin plate thickness center in the central axis direction of the pile body 3, as shown in FIG.
- FIG. 3 is a diagram schematically showing the relationship between the penetration position of the pile 1 in the vertical direction and the support layer 15 when the pile 1 is penetrated into the ground 11 where the support layer 15 is located below.
- FIG. 3A is a case where the upper end of the fin 5 is located in the support layer 15, and
- FIG. 3B is a case where the upper end of the fin 5 is not located in the support layer 15.
- the ground that is required to improve the pull-out support and push-in support of piles is that the support layer (hard ground) exists under the thick and soft ground. This is because, in soft ground, the pull-out support force and the push-in support force due to the peripheral friction between the pile body and the ground cannot be expected.
- the push-in support force not only enhances the pull-out support force due to the presence of the fins 5, but also improves the push-in support force. This is because, as described above, even when the pile 1 is pushed in, the ground that exerts the pushing bearing capacity expands near the lower end of the fin 5 due to the effect of the internal friction angle of the ground.
- the pull-out support force is exerted by the resistance due to the pull-out support force exerting ground 13. Therefore, it is desirable that the upper end of the fin 5 is located in the support layer 15 which is a strong ground having a large internal friction angle of the ground in order to make the ground 13 exhibiting the pull-out support force sufficiently wide. Further, in order to ensure that the upper end of the fin 5 is positioned in the support layer 15, it is desirable that the fin length lf is short within a range that does not impair the performance.
- the fin length lf is too short, it becomes difficult to temporarily fix the fin 5 with a jig when welding the fin 5 to the steel pipe pile body 3, and the workability at the time of attaching the fin 5 deteriorates. Since the size of the jig changes according to the outer diameter of the pile body 3, in the pile 1 according to the present embodiment, the vertical length lfv is the pile body so that the fin length lf is not too short.
- the outer diameter of 3 should be 0.5 times or more.
- the standard of the amount of penetration into the support layer in the driving pile method is about twice the outer diameter of the pile body in consideration of the strength of the construction machine and the pile body.
- the fins 5 are stably penetrated into the support layer 15, the upper end of the fins 5 is positioned in the support layer 15, and sufficient pull-out support force is exerted by the resistance of the ground 13.
- the vertical length lfv should be 1.75 times or less of the outer diameter D of the pile body 3 in order to exert the pull-out bearing capacity.
- the inclination angle ⁇ is 0 degrees or more and 45 degrees or less with respect to the central axis of the pile body 3 (see FIG. 1).
- the inclination angle ⁇ is an angle with respect to the central axis of the pile body 3 when the point at the 1/2 position of the fin length lf is the center of rotation.
- FIG. 4 shows a construction concept when a pile 1 having an inclination angle ⁇ of 1 to 45 degrees is vertically penetrated into the ground 11.
- the fins 5 When the inclination angle ⁇ is 0 degrees or more and less than 1 degree (FIG. 1 (a)), the fins 5 (vertical fins) are substantially parallel to the central axis of the pile body 3, so that the fins are the same as those of a general steel pipe pile. It will be a vertical penetration.
- the inclination angle ⁇ is 1 degree or more and 45 degrees or less (FIG. 1 (b))
- the fins 5 inclined with respect to the central axis of the pile body 3, so that a vertical load is applied to the pile 1.
- the soil slips through the fins 5 in the ground (black arrow in FIG. 4), and the pile 1 is rotated and penetrated. That is, when a vertical load is applied to the pile 1 to which the fins 5 are attached to the central axis of the pile body 3, the penetration resistance by the fins 5 can be relaxed by the rotation of the pile body 3.
- the pull-out support force of the pile 1 is exerted by the resistance of the ground 13 that exerts the pull-out support force.
- the larger the inclination angle ⁇ the higher the force transmitted from the fin 5 to the ground, the effect of the internal friction angle of the ground on the ground 13 exerting the pull-out support force near the upper end of the fin, and the higher the pull-out support force.
- the inclination angle ⁇ is large, the resistance force at the time of penetration becomes large, and the construction efficiency deteriorates. for that reason.
- the tilt angle ⁇ needs to consider not only the pull-out bearing capacity but also the penetration resistance. Hereinafter, the relationship between the tilt angle and the penetration resistance will be described.
- a normal force acts from the ground 11 to the fins 5, and along with this, a rotational force that rotates the pile body 3 around the central axis (referred to as "fin propulsion force").
- the normal force against the fin 5 is divided into the vertical direction of the ground 11 and the direction orthogonal to the vertical direction.
- the component force in the direction orthogonal to the vertical direction corresponds to the "fin propulsion force”.
- the vertical direction of the ground 11 coincides with the axial direction of the pile body 3
- the direction orthogonal to the vertical direction of the ground 11 coincides with the tangential direction with respect to the outer periphery of the pile body 3. Therefore, the fin propulsion force becomes the rotational force of the pile body 3.
- the fin propulsion force is increased when the inclination angle ⁇ is large at 60 degrees. It's getting smaller. As described above, if the inclination angle ⁇ is too large, the propulsive force becomes small, and as a result, the penetration resistance becomes large.
- the ratio of the fin propulsion force (rotational force of the pile body 3) to the vertical load does not decrease significantly, and the pile 1 can be penetrated without losing the rotational force of the pile body 3.
- the inclination angle ⁇ was set to 45 degrees or less.
- the lower limit of the inclination angle ⁇ is set to 0 degrees or more, but the inclination angle ⁇ is set to 1 degree or more in order to penetrate while rotating the pile body 3 at the time of construction and relax the penetration resistance. It is preferable to do.
- selection conditions "fin lower end position”, “fin upper end position”, “fin width”, “number of fins (upper limit)” and “fin spacing” will be described. These selection conditions can be set as necessary depending on the use of the pile, the purpose of the pile construction, the ground to be penetrated, the support layer, and the like.
- the lower end position of the fin 5 is preferably set so that the distance lt from the lower end of the pile body 3 to the lower end of the fin 5 is 50 mm or less (see FIG. 1). It is desirable that the mounting position of the fin 5 is closer to the lower end of the pile body 3, and the workability of the lower end of the pile body 3 and, for example, in the case of the steel pipe pile body 3, when the fin 5 is attached to the pile body 3. Weldability is taken into consideration.
- the upper end position of the fin 5 is preferably not more than twice the outer diameter D of the pile body 3 from the lower end of the pile body 3 (see FIG. 1).
- the position of the upper end of the fin 5 is based on the viewpoint that the fin 5 is stably penetrated into the support layer 15 and the upper end of the fin 5 is positioned in the support layer 15 as shown in FIG. 3 (a) described above. be.
- the fin width wf is preferably at least twice the fin plate thickness tf. Further, the fin width wf is preferably 1/2 or less of the outer diameter of the pile body 3 (see FIG. 1).
- the fin width wf is, as shown in FIG. 1, the length in the fin circumferential direction at the position 1/2 of the fin length lf.
- the pull-out support force increases as the range of the pull-out support force exerting ground 13 that resists when the pile 1 is pulled out is wide. Therefore, the larger the amount of protrusion from the surface of the pile body 3, the wider the ground 13 for exerting the pull-out bearing capacity, and the higher the effect can be exhibited.
- the lower limit of the fin width wf takes into consideration the attachability of the fin 5 to the pile body 3.
- the upper limit of the fin width wf is that when the outer diameter of the virtual circle passing through the outermost edge of the fin 5 is the fin outer diameter Df (see FIG. 1), the fin outer diameter Df is the outer diameter of the pile body 3 from the viewpoint of workability. This is because it is preferably up to about twice as much as.
- the number of fins 5 to be attached is preferably 16 or less. Further, the distance between the adjacent fins 5 is preferably 1/16 or more of the outer diameter D of the pile body 3 as the lower limit. The upper limit is preferably 1/2 or less. Here, the distance between the adjacent fins 5 is the distance at the center of the plate thickness of the fins 5 in the outer peripheral direction of the pile body 3.
- the reason why the number of fins 5 and the interval are within the above range is as follows. At least two fins are required to stably penetrate the pile 1 in the axial direction, and when the two fins 5 are attached at equal intervals in the outer peripheral direction of the pile body 3, the fin spacing is , It becomes 1/2 of the outer circumference length of the pile body 3.
- the upper limit of the number of fins 5 to be attached when a steel pipe is used for the pile body 3, the fins 5 are generally retrofitted to the pile body 3 by welding or the like. It is preferably as follows. Then, when 16 fins 5 are attached at equal intervals in the outer peripheral direction of the pile main body 3, the interval between the adjacent fins 5 is 1/16 of the outer peripheral length of the pile main body 3. If the number of fins 5 is within the above range, the larger the number of fins 5, the larger the bearing area at the upper end of the fins 5, so that the load transmitting force to the ground is increased and the pull-out bearing capacity is improved.
- the pile 1 according to the embodiment of the present invention is particularly preferably applicable to a harbor structure that requires a high pull-out support force and a push-in support force.
- the port structure referred to here refers to a pier, a stake on a quay, and the like.
- harbor structures it can also be applied to offshore wind foundations, building foundations, pier foundations, bedrock anchors, and the like. This is because these structures may also be required to have a high pull-out support force and a push-in support force.
- the pile 1 according to the present embodiment is most preferably used to penetrate into the support layer that exerts the maximum effect of the bearing capacity.
- the present invention can be applied to friction piles that do not penetrate the support layer and to diagonal piles. Further, it is possible to improve the pull-out support force and the push-in support force for general steel pipe piles (also called raw pipes).
- the fins 5 may be attached at unequal intervals as long as they are within the above fin spacing. Further, the fins 5 do not necessarily have to be attached symmetrically with respect to the central axis of the pile body 3, and may be attached asymmetrically by performing appropriate design and construction management. Further, the fin 5 shown in FIG. 1 is attached so as to rotate clockwise with respect to the central axis of the pile body 3, but may be attached so as to rotate counterclockwise. Further, although fins may be attached to the pile head, it is preferable not to attach fins to the pile head because it hinders the rotation of the pile generated during construction and causes disturbance of the ground. Even when the fins are substantially parallel, the piles may rotate depending on the condition of the ground and how the load is applied.
- the pile 1 according to the present embodiment can be applied not only to a steel pipe pile in which steel pipe fins are attached to a steel pipe pile body, but also to a concrete pile.
- the fins may also be made of concrete using a formwork.
- the pile has been described as an invention of the object, but in the pile 1 according to the embodiment of the present invention, the upper end of the fin 5 arranged at the lower end of the pile body 3 is located in the support layer. It can be used by the construction method that penetrates into.
- the pile 1 according to the present embodiment can be penetrated into the ground where the support layer exists.
- the construction method for penetrating the pile 1 used in this case into the ground is not particularly limited. It is possible to use known, known or unknown pile construction methods.
- the pile 1 according to the embodiment of the present invention a construction method of penetrating into the ground by a driving pile method or a press-fitting method can be applied. Further, the pile 1 according to the present embodiment is very suitable as a pile used in these construction methods. The reason is as follows.
- the pile 1 according to the present embodiment has a relatively small inclination angle ⁇ (see FIG. 1 (b))
- the resistance to the vertical load is small, and it is suitable for the driving pile method or the press-fitting method which is the construction by the vertical load. It can be said that there is.
- the pile 1 according to the present embodiment is constructed by the driving pile method and an example in which the pile 1 is constructed by the press-fitting method will be described.
- a hammer such as a weight is dropped to apply a striking load to the pile head, or the pile is vibrated to temporarily reduce the strength of the ground and relatively increase the vertical load due to its own weight. , Penetrate the stake.
- the pile is penetrated by applying a static press-fitting load to the pile head in the vertical direction. Even when these construction methods are used, it is a more preferable construction method to penetrate the pile into the ground so that the upper ends of the fins 5 arranged at the lower end of the pile body 3 are located in the support layer.
- the structure provided with the pile 1 according to the present embodiment may be a structure using the pile 1 according to the present embodiment.
- the pile according to the present invention is particularly suitable for harbor structures, offshore wind power foundations, building foundations, pier foundations, bedrock anchors, etc. among the structures.
- the pile 1 according to the present embodiment can be used in a method for constructing a structure including a step of penetrating the pile 1 into the ground.
- the pile 1 according to the present embodiment can also be used in the construction method of the structure including the above-mentioned construction method of the pile 1.
- the pile is described as the invention of the object, but the pile 1 according to the present embodiment is designed by the following design method. It is a pile design method in which two or more plate-shaped fins are arranged on the outer peripheral surface of the pile body at the lower end of the pile body, and each fin has a vertical length of the pile body. Set so that the outer diameter is 0.5 times or more and 1.75 times or less, and the inclination angle is 0 degrees or more and 45 degrees or less with respect to the central axis of the pile body.
- the order of the constituent requirements of the pile design method in the present invention is not limited to the order described above. Further, the preferable range of each selection condition such as the distance between adjacent fins, the lower end position and the upper end position of the fins, and the fin width is the same as the content described for the pile 1 according to the present embodiment as described above. Therefore, it is preferable to set each of these selection conditions within the preferable range described for the pile 1 as necessary.
- the pile 1 according to the present embodiment is also designed by the following design method.
- the target pull-out bearing capacity of the pile 1 according to the present embodiment is set.
- the inclination angle ⁇ and the upper limit of the number of fins are set according to the pull-out bearing capacity required for the pile 1. This is because the inclination angle ⁇ and the upper limit of the number of fins have a large influence on the pull-out bearing capacity.
- the inclination angle ⁇ is reduced and the number of fins is increased within the permissible range.
- economic efficiency is prioritized, the inclination angle ⁇ is increased within the permissible range, and the number of fins is reduced within the permissible range.
- the lower limit of the vertical length lfv is set according to the pull-out bearing capacity required for the pile 1.
- the fin width wf in addition to the vertical length lfv according to the pull-out bearing capacity required for the pile 1.
- the fin width wf is reduced within the allowable range and the vertical length lfv is increased within the allowable range.
- economic efficiency is prioritized, increase the fin width wf and reduce the vertical length lfv within the permissible range.
- the "allowable range” may be a range set according to the pull-out bearing capacity required for the pile 1, or the above-described embodiment of the present embodiment. It may be within the range of each condition of the fin 5 described in the pile 1 according to the above.
- the pile 1 according to the present embodiment is manufactured by the following manufacturing method.
- a method for manufacturing a pile in which two or more plate-shaped fins are arranged on the outer peripheral surface of the pile body at the lower end of the pile body, and each fin has a vertical length of the pile body. It is formed so that the outer diameter is 0.5 times or more and 1.75 times or less, and the inclination angle is 0 degrees or more and 45 degrees or less with respect to the central axis of the pile body.
- the order of the constituent requirements of the pile manufacturing method in the present invention is not limited to the order described above.
- the suitable range of each selection condition of the distance between the adjacent fins 5, the lower end position and the upper end position of the fins 5, and the fin width is related to the present embodiment. It is the same as the content described for the pile 1. Therefore, it is preferable that each of these selection conditions is formed in a suitable range described in pile 1 as necessary.
- the three-dimensional FEM model 21 for verification is a pile 23 equipped with a pile body 25 made of steel pipe and fins 27 made of steel plate (outer diameter (D) 609.6 mm, plate thickness 12 mm, length 9.34 m of the pile body 25).
- the ground 31 has a cylindrical shape with an outer diameter of 12 m and a height of 12 m, and a stratum boundary that separates the upper layer 33 (N value 20) and the lower layer 35 (N value 50) is provided at a depth of 8.12 m, and the support layer in the actual ground.
- the material data of the pile 23 and the ground 31 is a bilinear elasto-plastic model in which the secondary gradient changes at the yield point, and there are elements between the pile 23 and the ground 31 that can consider interaction behavior such as contact and friction. Incorporated.
- the pull-out bearing capacity of a general steel pipe pile is the loading load at the time of the standard pull-out amount, and the standard pull-out amount is 0.1 times the outer diameter of the steel pipe or 0.1 times the fin outer diameter. Therefore, in this embodiment, the reference pull-out amount is 0.1 times the outer diameter of the pile main body 25, and the load load at the reference pull-out amount is set as the pull-out load.
- the pull-out bearing capacity when the shape of the fin 27 in the pile 23 is changed is obtained.
- the specifications such as the shape of the fin 27 in the pile 23 are shown below (see FIG. 1).
- Eight fins 27 were provided on the outer peripheral surface of the pile body 25 at equal intervals.
- the vertical length lfv was set to 1 times, 1.75 times and 2.5 times (1D, 1.75D and 2.5D) the outer diameter D of the pile body 25.
- the distance lt from the lower end of the pile body 25 to the lower end of the fin 27 was set to 50 mm.
- the fin width wf was set to 0.25 times the outer diameter of the pile body 25. At this time, the fin outer diameter Df was set to 1.5 times the outer diameter D of the pile body 25.
- the tilt angle ⁇ was set to 0 degrees or 9.46 degrees.
- the tip angle ⁇ of the fin 27 was set to 60 degrees.
- the fin plate thickness tf was set to 25 mm. The specification is within the scope of the present invention except when the vertical length lfv is 2.5 times the outer diameter of the pile body 25.
- FIG. 7 shows the relationship between the loading load and the withdrawal amount when the vertical length lfv is changed in the pile 23 in which the inclination angle ⁇ is 0 degree.
- FIG. 7 also shows the reference withdrawal amount.
- the standard of the amount of penetration into the support layer in the driving pile method is about twice the outer diameter of the pile body in consideration of the strength of the construction machine and the pile body. Therefore, in this embodiment, in consideration of this point, the amount of pile penetration into the support layer is set to twice the outer diameter of the pile body 3 (that is, 2D). From FIG. 7, it was confirmed that when the vertical length lfv is as short as 1 times (1D) the outer diameter of the pile body 25, which is within the range of the present invention, the pull-out bearing capacity is the highest.
- the vertical length lfv is short, so that the upper end of the fin 27 is located deep in the lower layer 35 (support layer), the ground for exerting the pull-out support force becomes wider, and the pull-out support force is maximized. .. Further, even in the case of 1.75D in which the vertical length lfv is within the range of the present invention, since the upper end of the fin 27 is located in the lower layer 35, the pull-out bearing capacity close to that in the case of the vertical length lfv of 1D was obtained. Since the pull-out support force is exerted by the resistance of the pull-out support force exerting ground 13, it is clarified that the longer the distance between the upper end of the fin and the upper surface of the support layer, the more effective it is.
- the upper end of the fin 27 is not located in the lower layer 35 (support layer), so that the pull-out support force is exhibited.
- the resistance due to the ground 13 was insufficient, and the pull-out bearing capacity was not sufficiently exhibited.
- FIG. 8 shows the relationship between the load and the withdrawal amount when the vertical length lfv is changed in the pile 23 having the inclination angle ⁇ of 9.46 degrees. Similar to FIG. 7 described above, FIG. 8 also shows a reference drawing amount based on 0.1 times the outer diameter of the steel pipe.
- the distance between the upper end of the fin and the upper surface of the support layer according to this embodiment. It can be confirmed that 0.25D or more is sufficient.
- the vertical length lfv is as long as 2.5 times (2.5D) the outer diameter of the pile body 25, which is outside the scope of the present invention, the upper end of the fin 27 is not located in the lower layer 35 (support layer), so that the pull-out support force is obtained. The bearing resistance due to the exerted ground 13 was insufficient, and the pull-out bearing capacity was not sufficiently exerted.
- the present invention does not require large-scale equipment for construction, is excellent in economy and environment, and exhibits high pull-out support and high push-in support even under conditions where there is little penetration into the support layer. It is possible to provide piles, pile construction methods, structures, structure construction methods, pile design methods, and pile manufacturing methods that can suppress the occurrence of construction troubles.
Landscapes
- Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Piles And Underground Anchors (AREA)
Abstract
Description
フィン5は2枚以上とする。杭1の引き抜き支持力は、前述した図2に示すように、引き抜き支持力発揮地盤13による抵抗で発揮される。そして、フィン5の枚数が多いほどフィン5から地盤へ伝わる力が高まり、フィン上端付近における引き抜き支持力発揮地盤13での地盤の内部摩擦角の効果が高まり、引き抜き支持力は高まる。また、フィン5が存在することによって、引き抜き支持力を高めるだけでなく、杭1の押し込み時にもフィン5の下端付近では地盤の内部摩擦角の効果で押し込み支持力発揮地盤が広がるため、押し込み支持力も合わせて向上する。また、先に述べたように、フィン5が存在する(即ち、フィン5は1枚以上)ことで、引き抜き支持力を高めるだけでなく押し込み支持力も合わせて向上する。なぜならば、先に述べたように、杭1の押し込み時にもフィン5の下端付近では地盤の内部摩擦角の効果で押し込み支持力発揮地盤が広がるからである。そのため、フィン5の枚数は、杭1に要求される施工性と引き抜き支持力と押し込み支持力とによって決定される。さらに、本実施の形態においては、杭1を安定して軸方向へ貫入させるために、2枚以上とする。
鉛直長lfvは、杭本体3の外径Dに対して0.5倍以上1.75倍以下である(図1参照)。ここで、鉛直長lfvは、図1に示すように、杭本体3の中心軸方向におけるフィン板厚中心の下端と上端の距離である。
傾斜角度βは、杭本体3の中心軸に対して0度以上45度以下である(図1参照)。ここで、傾斜角度βは、フィン長lfの1/2位置における点を回転中心としたときの杭本体3の中心軸に対する角度とする。
フィン5の下端位置は、杭本体3の下端からフィン5の下端までの距離ltが50mm以下になるように設定することが好ましい(図1参照)。これは、フィン5の取り付け位置は杭本体3の下端に近いほど望ましく、杭本体3の下端の加工性や、例えば鋼管製の杭本体3にあってはフィン5を杭本体3に取り付ける際の溶接性等を考慮したものである。
フィン5の上端位置は、杭本体3の下端から杭本体3の外径Dの2倍以下とすることが好ましい(図1参照)。フィン5の上端位置に関しては、前述した図3(a)に示したように、フィン5を安定して支持層15に貫入させて支持層15内にフィン5の上端を位置させる観点によるものである。
フィン幅wfは、フィン板厚tfの2倍以上とすることが好ましい。また、フィン幅wfは、杭本体3の外径の1/2以下とすることが好ましい(図1参照)。ここで、フィン幅wfとは、図1に示すように、フィン長lfの1/2位置におけるフィン周方向の長さである。引き抜き支持力は、杭1を引き抜く際に抵抗する引き抜き支持力発揮地盤13の範囲が広いほど大きくなる。このため、杭本体3の表面からの突出量が大きいほど引き抜き支持力発揮地盤13が広範囲となり、高い効果を発揮できる。
フィン5を取り付ける枚数は16枚以下とするのが好ましい。また、隣り合うフィン5の間隔は、下限として杭本体3の外径Dの1/16以上とするのが好ましい。また、上限としては1/2以下とするのが好ましい。ここで、隣り合うフィン5の間隔は、杭本体3の外周方向におけるフィン5の板厚中心の距離とする。
本発明の作用効果を検証する解析を行ったので、以下、これについて説明する。当該解析では、図6に示す3次元FEMモデル21を用い、杭23の引き抜き支持力を求めた。
3 杭本体
5 フィン
11 地盤
13 引き抜き支持力発揮地盤
15 支持層
21 3次元FEMモデル
23 杭
25 杭本体
27 フィン
31 地盤
33 上層
35 下層
Claims (7)
- 杭本体の下端部に2枚以上の板状のフィンが前記杭本体の外周面に配設された杭であって、
前記各フィンは、
鉛直長が前記杭本体の外径の0.5倍以上1.75倍以下、
傾斜角度が前記杭本体の中心軸に対して0度以上45度以下である、杭。 - 請求項1に記載の杭を支持層が存在する地盤に貫入する杭の施工方法であって、
前記杭に配設された前記フィンの上端が、前記支持層内に位置するように貫入する、杭の施工方法。 - 請求項1に記載の杭を備える構造物。
- 請求項1に記載の杭を備えた構造物の構築方法であって、
前記杭を地盤に貫入する工程を含む、構造物の構築方法。 - 請求項1に記載の杭の設計方法であって、
前記杭に要求される引き抜き支持力に基づいて、前記傾斜角度を設定し、
その後、前記鉛直長の下限値を、前記引き抜き支持力に応じて設定する、杭の設計方法。 - 杭本体の下端部に2枚以上の板状のフィンが前記杭本体の外周面に配設された杭を設計する杭の設計方法であって、
前記各フィンは、
鉛直長が前記杭本体の外径の0.5倍以上1.75倍以下、
傾斜角度が前記杭本体の中心軸に対して0度以上45度以下となるように設定する、杭の設計方法。 - 杭本体の下端部に2枚以上の板状のフィンが前記杭本体の外周面に配設された杭を製造する杭の製造方法であって、
前記各フィンは、
鉛直長が前記杭本体の外径の0.5倍以上1.75倍以下、
傾斜角度が前記杭本体の中心軸に対して0度以上45度以下となるように形成する、杭の製造方法。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020237022089A KR20230112149A (ko) | 2021-01-06 | 2021-12-14 | 말뚝, 말뚝의 시공 방법, 구조물, 구조물의 구축 방법, 말뚝의 설계 방법 및 말뚝의 제조 방법 |
JP2022518648A JP7279855B2 (ja) | 2021-01-06 | 2021-12-14 | 杭、杭の施工方法、構造物、構造物の構築方法、杭の設計方法及び杭の製造方法 |
CN202180089071.1A CN116724159A (zh) | 2021-01-06 | 2021-12-14 | 桩、桩的施工方法、构造物、构造物的构筑方法、桩的设计方法及桩的制造方法 |
JP2023049470A JP2023068193A (ja) | 2021-01-06 | 2023-03-27 | 杭、杭の施工方法、構造物、構造物の構築方法、杭の設計方法及び杭の製造方法 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2021000658 | 2021-01-06 | ||
JP2021-000658 | 2021-01-06 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2022149421A1 true WO2022149421A1 (ja) | 2022-07-14 |
Family
ID=82357688
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2021/046069 WO2022149421A1 (ja) | 2021-01-06 | 2021-12-14 | 杭、杭の施工方法、構造物、構造物の構築方法、杭の設計方法及び杭の製造方法 |
Country Status (4)
Country | Link |
---|---|
JP (2) | JP7279855B2 (ja) |
KR (1) | KR20230112149A (ja) |
CN (1) | CN116724159A (ja) |
WO (1) | WO2022149421A1 (ja) |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6402432B1 (en) * | 1997-11-13 | 2002-06-11 | Kvaerner Cementation Foundations Limited | Method for installing load bearing piles utilizing a tool with blade means |
JP2004183339A (ja) * | 2002-12-04 | 2004-07-02 | Tama Kayaku Kiko Kk | 地中埋設部材 |
JP2006299601A (ja) * | 2005-04-19 | 2006-11-02 | Ciatec Ltd | 場所打ち杭の打設工法 |
JP2007113387A (ja) * | 2005-09-22 | 2007-05-10 | Rokuro Unno | 先端開放型既製杭及びそれに使用される掘削ヘッド |
JP2009068326A (ja) * | 2007-08-17 | 2009-04-02 | Jfe Steel Kk | 摩擦杭 |
JP2013237982A (ja) * | 2012-05-11 | 2013-11-28 | Earth Kensetsu:Kk | コンクリート杭 |
JP2017095880A (ja) * | 2015-11-18 | 2017-06-01 | 株式会社オーク | 鋼管杭の施工方法 |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0318238A (ja) | 1989-06-14 | 1991-01-25 | Nec Corp | 自動電源制御装置のキャリア信号監視方式 |
WO2012005197A1 (ja) | 2010-07-05 | 2012-01-12 | 新日本製鐵株式会社 | 鋼管杭及びその施工方法 |
CN111412112A (zh) | 2020-03-25 | 2020-07-14 | 丁红岩 | 一种可浮运的导管架打旋桩基础结构及其施工方法 |
-
2021
- 2021-12-14 WO PCT/JP2021/046069 patent/WO2022149421A1/ja active Application Filing
- 2021-12-14 JP JP2022518648A patent/JP7279855B2/ja active Active
- 2021-12-14 CN CN202180089071.1A patent/CN116724159A/zh active Pending
- 2021-12-14 KR KR1020237022089A patent/KR20230112149A/ko unknown
-
2023
- 2023-03-27 JP JP2023049470A patent/JP2023068193A/ja active Pending
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6402432B1 (en) * | 1997-11-13 | 2002-06-11 | Kvaerner Cementation Foundations Limited | Method for installing load bearing piles utilizing a tool with blade means |
JP2004183339A (ja) * | 2002-12-04 | 2004-07-02 | Tama Kayaku Kiko Kk | 地中埋設部材 |
JP2006299601A (ja) * | 2005-04-19 | 2006-11-02 | Ciatec Ltd | 場所打ち杭の打設工法 |
JP2007113387A (ja) * | 2005-09-22 | 2007-05-10 | Rokuro Unno | 先端開放型既製杭及びそれに使用される掘削ヘッド |
JP2009068326A (ja) * | 2007-08-17 | 2009-04-02 | Jfe Steel Kk | 摩擦杭 |
JP2013237982A (ja) * | 2012-05-11 | 2013-11-28 | Earth Kensetsu:Kk | コンクリート杭 |
JP2017095880A (ja) * | 2015-11-18 | 2017-06-01 | 株式会社オーク | 鋼管杭の施工方法 |
Also Published As
Publication number | Publication date |
---|---|
CN116724159A (zh) | 2023-09-08 |
KR20230112149A (ko) | 2023-07-26 |
JP7279855B2 (ja) | 2023-05-23 |
JP2023068193A (ja) | 2023-05-16 |
JPWO2022149421A1 (ja) | 2022-07-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR101620380B1 (ko) | 스파이럴 강관 말뚝 | |
US9598831B2 (en) | Helical screw pile | |
JP5867301B2 (ja) | 管杭及びその施工方法 | |
WO2022149421A1 (ja) | 杭、杭の施工方法、構造物、構造物の構築方法、杭の設計方法及び杭の製造方法 | |
JP4705506B2 (ja) | 回転圧入鋼管杭及び鋼管杭を用いた圧入工法 | |
AU2018333273B2 (en) | A pile | |
JP5919675B2 (ja) | 複合基礎杭及び複合基礎杭の構築方法 | |
JP3170756B1 (ja) | ねじ込み式鋼管杭及びその施工方法 | |
JP3216048B2 (ja) | ねじ込み式鋼管杭 | |
JP2004285698A (ja) | 異形既製杭 | |
KR101991291B1 (ko) | 연직 보강부재에 의한 헬릭스 날개의 보강구조를 가지는 헬리컬 파일 | |
KR101791211B1 (ko) | 좌굴 보강용 헬릭스 강관 말뚝의 시공 방법 | |
JP5685493B2 (ja) | 基礎構造 | |
KR20190012273A (ko) | 나선상 블레이드가 부착된 강관 말뚝 및 합성 말뚝 그리고 합성 말뚝의 조성 방법 | |
JP2001348867A (ja) | ねじ込み式鋼管杭及びその施工方法 | |
JP5169957B2 (ja) | 杭の施工方法及び杭の施工治具 | |
KR102097904B1 (ko) | 회전형 강관말뚝 | |
KR102259937B1 (ko) | 관입성 향상 헬리컬 파일 | |
US20110185649A1 (en) | Helical Anchor with Lead | |
JP4943363B2 (ja) | 鋼管杭およびその施工方法 | |
KR20100076577A (ko) | 비대칭 회전날개를 구비하는 강관파일 | |
KR20200074495A (ko) | 파일 캡 | |
JP7277726B2 (ja) | 鋼管杭および鋼管杭の施工方法 | |
JP5822195B2 (ja) | 基礎杭ピン結合構造 | |
JP3031245B2 (ja) | ねじ込み式鋼管杭 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
ENP | Entry into the national phase |
Ref document number: 2022518648 Country of ref document: JP Kind code of ref document: A |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 21917642 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 20237022089 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 202180089071.1 Country of ref document: CN |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 21917642 Country of ref document: EP Kind code of ref document: A1 |