Steel pipe Hangzhou joint structure
The joint structure with controlled gaps between recesses, protrusions, and pin holes in steel pipe piles ensures even load distribution and maintains mechanical strength, addressing assembly challenges and ease of insertion.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- SYST MEASURING
- Filing Date
- 2022-06-21
- Publication Date
- 2026-05-27
AI Technical Summary
Existing steel pipe pile joint structures require precise dimensional matching and alignment to prevent gaps that can lead to irregular loads or difficulty in pin insertion, affecting the durability and ease of assembly.
A joint structure with gaps of 0.1 to 3.0 mm between recesses and protrusions, and between the inner diameter of pin holes and the outer diameter of the pin, ensuring even load distribution and no adverse effects on mechanical strength.
The proposed gaps allow for equal load distribution without compromising mechanical strength, maintaining shear, pull-out, torsional, and compressive strengths, and facilitating easier pin insertion.
Smart Images
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Abstract
Description
Technical Field
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[0001] The present invention relates to an improvement in the joint structure of steel pipe piles.
Background Art
[0002] Steel pipe piles for construction and civil engineering works are added according to the ground conditions and driven to a desired depth. Although various measures for connecting steel pipe piles have been proposed, as one aspect, there is a structure in which joints are respectively connected to the upper end of the lower steel pipe pile and the lower end of the upper steel pipe pile, and both are connected by pins. When a rotational force is applied to a steel pipe pile, a joint structure having a concave-convex fitting structure has been proposed (Patent Document 1) in order to reliably transmit the rotational force of the upper steel pipe pile on the rotational drive source side to the lower steel pipe pile. In such a joint structure, circumferential concavities and convexities are respectively formed on the upper joint and the lower joint, and the upper convex portion fits into the lower concave portion, and the upper concave portion fits into the lower convex portion. Here, the lower joint has a large-diameter portion, and the above-mentioned concavities and convexities are formed on the inner peripheral side thereof, and the upper joint has a small-diameter portion, and the above-mentioned concavities and convexities are formed on the outer peripheral side thereof. The rotational force is reliably transmitted by the contact of the opposing side surfaces in the concave and convex portions. In the state where the concavities and convexities are fitted, the pin holes formed in the convex portion communicate with the pin holes formed in the large-diameter portion and the small-diameter portion, and a connecting pin is inserted into the communicated pin holes. Thereby, the upper joint and the lower joint are mechanically connected.
Prior Art Documents
[0005] As a result of diligent research to solve the above problems, the inventors realized that a gap should be provided between the recess and the protrusion, and between the inner diameter of the pin hole and the outer diameter of the pin. In other words, the first aspect of this invention is defined as follows: A joint structure for a steel pipe pile comprising an inner first joint connected to the end of a first steel pipe pile, an outer second joint connected to the end of a second steel pipe pile, and a pin, wherein the first joint and the second joint are connected by the pin, The inner first joint comprises a small diameter portion and a first fitting portion formed on the outside of the small diameter portion, the first fitting portion comprises a first recess and a first protrusion, the outer second joint comprises a large diameter portion and a second fitting portion formed on the inside of the large diameter portion, the second fitting portion comprises a second recess and a second protrusion, With the first joint inserted into the second joint, the first protrusion and the second recess and the first recess and the second protrusion are fitted together, and the first pin holes of the first and second protrusions and the second pin holes formed in the small diameter portion and the large diameter portion have an inner diameter L1 and are in communication with each other. A first pin with an outer diameter L2 is inserted into the first pin hole and the second pin hole, and a first gap of 0.1 to 3.0 mm is formed between the inner diameter L1 and the outer diameter L2. A second gap of 0.1 to 3.0 mm is also formed between the opposing surfaces of the first fitting portion and the second fitting portion in the fitted state. The lengths of the first gap and the second gap are equal. Joint structure.
[0006] When a load (axial or circumferential) is applied between the first and second joints, the recesses and protrusions abut against the surfaces facing the direction of the applied load, and similarly, the pin also abuts against the inner surface of the pinhole facing the direction of the applied load. Since the distance between the first and second gaps is equal, there are no gaps between the opposing surfaces between the first and second fitting parts, and between the inner surface of the pinhole and the opposing surface of the pin; they all abut. As a result, an even load is applied to each of the above-mentioned contact surfaces. This contact state is substantially the same as the state of each contact surface when the recesses and protrusions are fitted together without gaps and the pin is inserted into the pinhole without gaps. Therefore, when a load is applied to one of the steel pipe piles with the first and second joints fitted together, there is no adverse effect on the mechanical strength of the pins or the joints themselves due to the first or second gap. In other words, the mechanical strength, including the pin's load-bearing capacity (shear strength, pull-out strength) and the load-bearing capacity between the upper and lower joints (torsional strength, compressive strength), is basically the same as that of a conventional joint design that eliminates gaps. The gap, the length of the gap, and the allowable tolerances for both can be arbitrarily selected depending on the material and application (applied load) of the joint.
[0007] The second aspect of this invention is defined as follows: In the first aspect of the joint structure, the second gap is the distance between axially opposing surfaces and between circumferentially opposing surfaces between the fitting portion and the second fitting portion.
[0008] According to the second-faced joint structure defined in this manner, a second gap of the same length as the first gap is formed between the axially opposing surfaces and the circumferentially opposing surfaces of the first and second fitting portions. Therefore, when an axial load is applied to the joint, or (simultaneously) when a circumferential load is applied, the opposing surfaces of the first and second fitting portions come into contact, and the inner circumferential surface of the pin hole also comes into contact with the opposing surface of the pin. Consequently, no adverse effects on the mechanical strength of the joint structure due to the first and second gaps occur.
[0009] In the above, we have described a joint structure in which protrusions and recesses are fitted together. Some joint structures do not have protrusions or indentations. In such joint structures, extending from the above explanation, it can be seen that it is sufficient to provide the aforementioned second gap only in the axial direction. This second gap refers to the gap between opposing surfaces in the axial direction in the second joint of the first joint. For example, in a joint structure in which a first joint connected to an upper steel pipe is inserted into and fitted into a second joint connected to a lower steel pipe, when both the first and second joints are cylindrical members (without any protrusions or indentations), a flange is provided on the upper edge of the first joint, and the upper edge of the second joint abuts against this flange. In such a joint structure, the design distance between the lower surface of the flange and the upper edge of the second joint becomes the second gap. Therefore, the third aspect of this invention is defined as follows: A joint structure for a steel pipe pile comprising an inner first joint connected to the end of a first steel pipe pile, an outer second joint connected to the end of a second steel pipe pile, and a pin, wherein the first joint and the second joint are connected by the pin, A portion or all of the inner first joint is inserted into a portion or all of the outer second joint. The first and second connectors are provided with pin holes having an inner diameter L1. A pin with an outer diameter L2 is inserted into the pin hole. A first gap of 0.1 to 3.0 mm is formed between the inner diameter L1 and the outer diameter L2. In the fitted state of the first joint and the second joint, a second gap of 0.1 to 3.0 mm is also formed between the axially opposing surfaces. The lengths of the first gap and the second gap are equal. Socket joint structure.
[0010] The present invention can also be defined as follows. A pipe pile driving method using a socket joint structure of a pipe pile, comprising an inner first socket joint connected to an end of a first pipe pile, an outer second socket joint connected to an end of a second pipe pile, and a pin, wherein the first socket joint and the second socket joint are connected by the pin, In the socket joint structure, part or all of the inner first socket joint is inserted into part or all of the outer second socket joint, The first socket joint and the second socket joint are provided with pin holes having an inner diameter L1, A pin having an outer diameter L2 is inserted into the pin hole, A first gap is formed between the inner diameter L1 and the outer diameter L2, A socket joint structure is used in which a second gap is also formed between the opposing surfaces of the first socket joint and the second socket joint in the fitted state, When a load is applied to the first steel pipe or the second steel pipe, the inner diameter of the pin hole and the outer diameter of the pin are brought into contact with each other in the direction of the load application, and the opposing surfaces of the first socket joint and the second socket joint are also brought into contact with each other.
Brief Description of the Drawings
[0011] [Figure 1] FIG. 1 shows the first socket joint of the socket joint structure of the present invention, FIG. 1A is a front view, FIG. 1B is a cross-sectional view, and FIG. 1C is a longitudinal sectional view. [Figure 2] FIG. 2 shows the second socket joint of the socket joint structure of the present invention, FIG. 1A is a front view, FIG. 1B is a cross-sectional view, and FIG. 1C is a longitudinal sectional view. [Figure 3] FIG. 3 shows a state where the first socket joint is inserted into the second socket joint and both are fixed with a pin, FIG. B is a cross-sectional view thereof, and FIG. C is a longitudinal sectional view thereof. [Figure 4]FIG. 4A is a developed view showing the fitting state (no-load state) of the second ring (first fitting portion) of the first joint and the second ring (second fitting portion) of the second joint. FIG. 4B shows the contact state of the pins and pin holes when a load is applied downward in the drawing. FIG. 4C shows the contact state of the pins and pin holes when a load is applied to the left in the drawing. FIG. 4D shows the contact state of the pins and pin holes and the contact state between the first ring and the second ring when a load is applied downward and to the left in the drawing.
Embodiments for Carrying Out the Invention
[0012] FIG. 1 shows the first joint 10. FIG. 1A is a front view, FIG. 1B is a cross-sectional view, and FIG. 1C is a longitudinal sectional view. The first joint 10 includes a cylindrical first ring 11 and a second ring 12 outside it. The first ring 11 forms a small-diameter portion, and pin holes 11-1 (second pin holes) are drilled circumferentially evenly in the middle of it. The second ring 12 forms a first fitting portion. Leaving its upper edge 16, it is cut out like a comb, and convex portions 13 and concave portions 15 are formed. A pin hole 13-1 is formed in the convex portion 13. This pin hole 13-1 has the same diameter as the pin hole 11-1 of the first ring 11 and communicates with it (the centers coincide).
[0013] The first ring 11 and the second ring 12 are formed of steel material and are joined by welding at the position of w. The lower edge of the upper steel pipe pile A is welded to the upper edge of the first ring 11 and / or the second ring 12. The diameter, length, and material of the first ring 11 and the second ring 12 are arbitrarily designed according to the use of the steel pipe pile.
[0014] FIG. 2 shows the second joint 20. FIG. 2A is a front view, FIG. 2B is a cross-sectional view, and FIG. 2C is a longitudinal sectional view. The second joint 20 includes a cylindrical first ring 21 and a second ring 22 inside it. The first ring 21 forms a large-diameter portion, and pin holes 21-1 (second pin holes) are drilled circumferentially evenly in the middle of it. The second ring 22 constitutes the second fitting portion, and is notched in a comb-like manner, leaving its lower edge 26, to form a convex portion 23 and a concave portion 25. A pin hole 23-1 is formed in the convex portion 23, and this pin hole 23-1 is the same diameter as the pin hole 21-1 of the first ring and communicates with it (their centers coincide).
[0015] The first ring 21 and the second ring 22 are made of steel and are joined by welding at position w. The upper edge of the lower steel pipe pile B is welded to the lower edge of the first ring and / or the second ring. The diameter, length, and material of the first ring 21 and the second ring 22 are arbitrarily designed according to the application of the steel pipe pile. The pin holes 21-1 and 23-1 of the second joint are of the same diameter as and communicate with the pin holes 11-1 and 13-1 of the first joint.
[0016] Figure 3 shows the state in which the first connector 10 is inserted into the second connector 20 and both are fixed with a pin P. The small-diameter first connector 10 is inserted into the second connector 20, and the lower edge of the protrusion 13 of the second ring 12 abuts against the lower edge 26 of the second ring 22 of the second connector 20. On the other hand, the upper edge of the protrusion 23 of the second joint 20 abuts against the upper edge 16 of the second ring 12 of the first joint 10.
[0017] With the first connector 10 and the second connector 20 fitted together, the respective pin holes 11-1, 13-1, 21-1, and 23-1 are in communication, and pin P is inserted therein. The tip of this pin P is equipped with a hook P1 made of spring steel. When unloaded, this hook P1 protrudes from the pin P and engages with the periphery of the pin hole 11-1 to prevent it from coming loose. When inserted into the pin hole, this hook P1 retracts in diameter. Since there is a difference between the inner diameter L1 of each pin hole and the outer diameter L2 of the main body of the pin P (L1 > L2), the hook P1 is more likely to shrink in diameter when it is driven in, making the driving operation easier.
[0018] Figure 4 is an exploded view showing the fitted state of the second ring 12 of the first joint 10 and the second ring 22 of the second joint 20. Figure 4A shows the mating state under no load. There is a difference (gap) of 2S1 between the outer diameter (diameter) of pin P and the inner diameter (diameter) of pin holes 13-1 and 23-1. There is also a gap of 2S2 between adjacent circumferential surfaces of the second ring 12 and the second ring 22, and between a pair of adjacent axial surfaces. That is, there is a gap of S2 between the side edge of the first protrusion 13 and the side edges of the pair of second protrusions 23 that sandwich it. Similarly, there is a gap of S2 between the lower edge of the first protrusion 13 and the lower edge 26 of the second recess 25, and a gap of S2 between the upper edge of the second protrusion 23 and the upper edge 16 of the first recess 15. When a downward axial load is applied to the first joint 10 and the second joint 20, as shown in Figure 4B, the pin P inserted into the pin hole 23-1 abuts against the lower edge of the inner surface of the pin hole 23-1. On the other hand, the pin P inserted into the pin hole 13-1 abuts against the upper edge of the inner surface of the pin hole 13-1. Figure 4B shows the pin holes 13-1 and 23-1 formed in the first protrusion 13 and the second protrusion 23. As shown in Figure 3B, these pin holes 13-1 and 23-1 communicate with the pin holes 11-1 and 21-1 of the first ring 12 and the second ring 21, respectively, which are of the same diameter. When the first joint 10 and the second joint 20 are fitted together as designed, the inner surfaces of the communicating pin holes become flush. On the other hand, the first joint 10 and the second joint 20 may deform, or errors may occur in their manufacture. In that case, the inner surfaces of the communicating pin holes will not become flush, and the pin P will only contact the inner surface of one of the pin holes. Anticipating such a case, it is preferable to reinforce the area around the pin holes. As a means of reinforcement, material can be added around the pin holes, or a separate cylindrical member with high mechanical rigidity can be driven into the pin holes. The inner circumference of the cylindrical member should be 1.0 to 3.0 mm thick.
[0019] When a load is applied to the first joint 10 and the second joint 20 in the circumferential direction (to the left in the figure), as shown in Figure 4C, the pin P inserted into the pin hole 23-1 will come into contact with the right edge of the inner circumferential surface of the pin hole 23-1. Similarly, the pin P inserted into the pin hole 13-1 will also come into contact with the right edge of the inner circumferential surface of the pin hole 13-1.
[0020] Figure 4D shows the state when axial and circumferential loads are applied to the first joint 10 and the second joint 20. The first protrusion 13 abuts against the lower edge 26 of the second ring, and the left-side edge of each protrusion 13 of the first ring 11 abuts against the right-side edge of each protrusion 23 of the second ring 22. Pin P abuts against the lower right edge on the inner circumferential surface of pin holes 13-1 and 23-1. This state is maintained while a load is applied to the first joint 10 and the second joint 20, so there is no adverse effect on the mechanical strength of the joint structure.
[0021] In the above, the gap S1 between the pin and the inner circumference of the pin hole is preferably 0.1 mm to 3.0 mm. More preferably, it is about 0.5 mm. Similarly, the gap S2 between the edge of the element of the first joint 10 (such as the protrusion 13 in the example shown) and the edge of the element of the second joint (such as the lower edge 26 in the example shown) is preferably 1 mm to 3.0 mm. More preferably, it is about 0.5 mm. It is preferable that the gaps 2S1 and 2S2 be the same length. This ensures that all pins contact the inner circumferential surface of the pin holes, and all protrusions 13 and 23 also contact their respective mating members.
[0022] As described above, the present invention is not limited to the embodiments described above, and can be modified as appropriate within the scope that can be easily conceived by a person skilled in the art without departing from the scope of the claims. [Explanation of Symbols]
[0023] 10 1st joint 11-1, 13-1, 21-1, 23-1 pin holes 13. First protrusion 15. First recess 20 Second joint 23 Second protrusion 25 Second recess A, B steel pipe piles B Steel pipe pile P pin S1 Gap S2 Gap
Claims
1. A joint structure for a steel pipe pile comprising an inner first joint connected to the end of a first steel pipe pile, an outer second joint connected to the end of a second steel pipe pile, and a pin, wherein the first joint and the second joint are connected by the pin, The inner first joint comprises a small diameter portion and a first fitting portion formed on the outside of the small diameter portion, the first fitting portion comprises a first recess and a first protrusion, the outer second joint comprises a large diameter portion and a second fitting portion formed on the inside of the large diameter portion, the second fitting portion comprises a second recess and a second protrusion, With the first joint inserted into the second joint, the first protrusion and the second recess and the first recess and the second protrusion are fitted together, and the first pin holes of the first and second protrusions and the second pin holes formed in the small diameter portion and the large diameter portion have an inner diameter L1 and are in communication with each other. A first pin with an outer diameter L2 is inserted into the first pin hole and the second pin hole, and a first gap of 0.1 to 3.0 mm is formed in the circumferential direction between the inner diameter L1 and the outer diameter L2 when the first pin is inserted so as to coincide with the centers of the first pin hole and the second pin hole. A second gap of 0.1 to 3.0 mm is also formed between the opposing surfaces of the first fitting portion and the second fitting portion in the fitted state. The lengths of the first gap and the second gap are equal. Joint structure.
2. The joint structure according to claim 1, wherein the second gap is the distance between axially opposing surfaces and between circumferentially opposing surfaces between the first fitting portion and the second fitting portion.
3. A joint structure for a steel pipe pile comprising an inner first joint connected to the end of a first steel pipe pile, an outer second joint connected to the end of a second steel pipe pile, and a pin, wherein the first joint and the second joint are connected by the pin, A part or all of the inner first joint is inserted into a part or all of the outer second joint. The first and second connectors are provided with pin holes having an inner diameter L1. A pin with an outer diameter L2 is inserted into the pin hole. Between the inner diameter L1 and the outer diameter L2, when the pin is inserted so as to coincide with the center of the pin hole, a first gap of 0.1 to 3.0 mm is formed in the entire circumferential direction. A second gap of 0.1 to 3.0 mm is also formed between the axially opposing surfaces of the first and second joints in the fitted state. The lengths of the first gap and the second gap are equal. Joint structure.
4. A pile driving method using a steel pipe pile joint structure comprising an inner first joint connected to the end of a first steel pipe pile, an outer second joint connected to the end of a second steel pipe pile, and a pin, wherein the first joint and the second joint are connected by the pin, The aforementioned joint structure is such that part or all of the inner first joint is inserted into part or all of the outer second joint. The first and second connectors are provided with pin holes having an inner diameter L1. A pin with an outer diameter L2 is inserted into the pin hole. Between the inner diameter L1 and the outer diameter L2, when the pin is inserted so as to coincide with the center of the pin hole, a first gap is formed in the entire circumferential direction. A joint structure is used in which a second gap is formed between the axially and / or circumferentially opposing surfaces of the first joint and the second joint in the fitted state, A pile driving method wherein, when a load is applied to the first steel pipe pile or the second steel pipe pile, the inner diameter of the pin hole and the outer diameter of the pin are brought into contact in the direction of the applied load, and the opposing surfaces of the first joint and the second joint are also brought into contact.