Non-prestressed steel bar and end plate connecting structure of precast concrete pile

Abstract

This utility model discloses a connection structure between non-prestressed steel bars and an end plate for a precast concrete pile. It includes multiple non-prestressed steel bars arranged along the circumference of the end plate, each penetrating the entire length of the precast concrete pile. One end of each non-prestressed steel bar is fixedly connected to an end plate at that end. The other end of each non-prestressed steel bar is connected to a stepped threaded sleeve with a larger outer end and a smaller inner end. The end plate at the other end has multiple axial through holes for sliding the small-diameter section of the stepped threaded sleeve. The end plate also has an axial limiting surface that, after tensioning the multiple prestressed steel bars, axially limits the stepped threaded sleeve, thus rigidly fixing each non-prestressed steel bar to the end plate. Before tensioning the multiple prestressed steel bars, an axial gap is maintained between the stepped surface of the stepped threaded sleeve and the axial limiting surface of the end plate at the other end for tensioning. This connection structure can significantly improve the ductility, toughness, and pull-out resistance of the precast concrete pile.

Description

Technical Field

[0001] This utility model relates to the field of foundation construction technology, specifically to a connection structure between non-prestressed steel bars and end plates of precast concrete piles. Background Technology

[0002] Precast concrete piles in the prior art generally include end plates at both ends, multiple prestressed steel bars running through the entire length of the precast concrete pile, or precast concrete pile, and multiple prestressed steel bars evenly arranged along the circumference. The end of each prestressed steel bar is fixed to its respective end plate. If the prestressed steel bar passes through the hole on the end plate, it is fixed by its own end cap. At least one end of the multiple prestressed steel bars is the tensioning end. For example, tensioning one of the end plates can tension multiple prestressed steel bars.

[0003] In practical applications, such as for tension piles, some precast concrete piles with prestressed steel bars require enhanced strength and mechanical properties. Therefore, they are generally equipped with multiple non-prestressed steel bars. These non-prestressed steel bars can be arranged circumferentially or evenly. The number of non-prestressed steel bars can be equal to or unequal to the number of prestressed steel bars. For example, the number of non-prestressed steel bars can be less or more than the number of prestressed steel bars.

[0004] However, existing technologies for precast concrete piles with multiple prestressed and non-prestressed steel bars still have the following shortcomings in the arrangement of multiple non-prestressed steel bars: Since multiple prestressed steel bars are connected to the reinforcing cage, before pouring the precast concrete pile, at least one end plate needs to be tensioned to tension all prestressed steel bars. If the multiple non-prestressed steel bars are fixed to both end plates before tensioning, the tensioning process will inevitably pull off the fixed connection between the non-prestressed steel bars and either end plate. To avoid this, existing technologies generally use the following arrangement for multiple non-prestressed steel bars: Anchor steel bars equal in number to the number of non-prestressed steel bars are fixed to both end plates. A section of the anchor steel bar extending into the precast concrete pile is lapped and tied to one end of each non-prestressed steel bar. Because the anchor steel bar and the non-prestressed steel bar have an overlapping section and are lapped, the connection between the anchor steel bar and the non-prestressed steel bar will not detach when the prestressed steel bar is tensioned. However, because each prestressed steel bar is not rigidly fixed to the end plate after tensioning, the ductility, toughness and pull-out resistance of the precast concrete pile are still relatively lacking. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a connection structure between the non-prestressed steel bars and the end plate of a precast concrete pile that can significantly improve the ductility, toughness and pull-out resistance of the precast concrete pile.

[0006] The technical solution of this utility model is to provide a connection structure between non-prestressed steel bars and end plates of precast concrete piles, including multiple non-prestressed steel bars arranged along the circumference of the end plate, each non-prestressed steel bar penetrating the entire length of the precast concrete pile; one end of each non-prestressed steel bar is fixedly connected to the end plate at one end; the other end of each non-prestressed steel bar is connected to a stepped threaded sleeve with a larger outer end and a smaller inner end, the end plate at the other end has multiple axial through holes for sliding the small diameter section of the stepped threaded sleeve, and the end plate at the other end also has an axial limiting surface for axially limiting the stepped threaded sleeve after the multiple prestressed steel bars are tensioned, so that each non-prestressed steel bar is rigidly fixedly connected to the end plate; before the multiple prestressed steel bars are tensioned, there is an axial gap between the stepped surface of the stepped threaded sleeve and the axial limiting surface of the end plate at the other end for tensioning.

[0007] With the above structure, the connection structure between the non-prestressed steel bars and the end plates of the precast concrete pile of this utility model has the following advantages: Since each non-prestressed steel bar runs through the entire length of the precast concrete pile, and a tensioning gap is left between the stepped surface of the stepped threaded sleeve and the axial limiting surface of the end plate at the other end before the prestressed steel bar is tensioned, the fixed connection points between the two ends of the non-prestressed steel bar and the two end plates will not be damaged. After the prestressed steel bar is tensioned, the stepped surface of the stepped threaded sleeve can abut against the axial limiting surface of the end plate at the other end, that is, the non-prestressed steel bar is straightened and both ends are rigidly fixedly connected to their respective end plates. This significantly improves the ductility, toughness, and pull-out resistance of the precast concrete pile using this connection structure, and also significantly enhances its bearing capacity and bending resistance, effectively ensuring good ductility, toughness, pull-out resistance, bearing capacity, and bending resistance of the precast concrete pile using this connection structure.

[0008] Furthermore, the first stepped threaded sleeve is provided with a first cylindrical internal threaded hole, and the other end of each non-prestressed tendon is provided with a first external thread for tightening with the internal thread of the first cylindrical internal threaded hole. With the above structure, the stepped threaded sleeve and the other end of the non-prestressed steel bar are directly threaded together, which is relatively simple and further effectively ensures the good ductility, toughness, pull-out resistance, bearing capacity and bending resistance of the precast concrete pile using the connection structure of this utility model.

[0009] Furthermore, the small-diameter section of the second stepped threaded sleeve is provided with a second external thread. The other end of each non-prestressed steel bar passes through the first central hole of a connecting sleeve. The end of the other end of each non-prestressed steel bar has an upsetting head axially limited by the retaining ring of the connecting sleeve. The connecting sleeve has an internal thread of a second straight cylindrical internal thread hole for tightening with the second external thread of the small-diameter section of the second stepped threaded sleeve. With the above structure, the stepped threaded sleeve and the other end of the non-prestressed steel bar are indirectly threadedly connected through the connecting sleeve. Only the stepped threaded sleeve and the connecting sleeve need to be screwed together, making the connection relatively convenient and quick. This further effectively ensures the good ductility, toughness, pull-out resistance, bearing capacity, and bending resistance of the precast concrete pile using the connection structure of this utility model.

[0010] Furthermore, the axial through hole on the end plate at the other end is a stepped hole for axial sliding of the stepped threaded sleeve. The inner end of the stepped hole is a small-diameter hole for axial sliding of the small-diameter section of the stepped threaded sleeve, and the outer end of the stepped hole is a large-diameter hole for axial sliding of the large-diameter section of the stepped threaded sleeve. The axial limiting surface refers to the stepped limiting surface that limits the stepped surface of the stepped threaded sleeve. With the above structure, the axial through hole includes both the axial through hole for axial sliding of the small-diameter section of the stepped threaded sleeve and the axial through hole for axial sliding of the large-diameter section of the stepped threaded sleeve. Moreover, the axial limiting surface of the end plate at the other end is the stepped limiting surface of the large-diameter hole inside the axial through hole, which makes the guiding effect of the axial through hole on the stepped threaded sleeve better. After tensioning, the fixed connection effect between the other end of the non-prestressed steel bar and the stepped threaded sleeve and the end plate at the other end is better, further improving the rigid fixed connection effect between the two ends of the non-prestressed steel bar and the two end plates.

[0011] Furthermore, the axial clearance is greater than the actual tensioning distance of the prestressed steel bars. Each stepped threaded sleeve has an outer end with a force-applying structure for tightening the stepped threaded sleeve to the other end of each non-prestressed steel bar, thereby fixing the non-prestressed steel bar to the end plate. The force-applying structure is like two symmetrical force-applying holes. With this structure, the tensioning effect of multiple prestressed steel bars is better, and after tensioning, the process of fixing the other end of the non-prestressed steel bar to the stepped threaded sleeve and the end plate at the other end is more convenient and faster. The fixing effect of the other end of the non-prestressed steel bar to the stepped threaded sleeve and the end plate at the other end is better, and further improves the rigid fixing effect of the two ends of the non-prestressed steel bar to the two end plates.

[0012] Furthermore, the connection structure between the top end of the non-prestressed steel bar of the top section of the precast concrete pile, which is composed of multiple precast concrete piles, and the top end plate adopts a connection structure between the other end of the non-prestressed steel bar and the other end plate. The internal threads of part or all of the first straight cylindrical internal thread hole of the stepped threaded sleeve are used to screw and fix the lower end of the anchoring steel bar of the pile cap. With the above structure, the anchoring steel bar and non-prestressed steel bar of the top pile cap of each precast concrete pile are coaxial, making connection convenient and quick, and the connection firm and reliable. Furthermore, since each anchoring steel bar can press against the top end of the non-prestressed steel bar located at the lower end of the first straight cylindrical internal thread hole of the stepped threaded sleeve, or the top end of the non-prestressed steel bar located at the lower end of the stepped sleeve, axial limiting provides double insurance, further ensuring a better technical effect of rigid fixed connection between the two ends of the non-prestressed steel bar and the end plates. This further ensures the good ductility, toughness, pull-out resistance, bearing capacity, and bending resistance of the precast concrete pile using the connection structure of this utility model.

[0013] Furthermore, the fixed connection between one end of the non-prestressed steel bar and the end plate refers to the fourth external thread of one end of each non-prestressed steel bar being screwed into the third straight cylindrical internal thread hole of the end plate. When the non-prestressed steel bar at the lower end of each precast concrete pile section is connected to the end plate using the above structure, the fixed connection process is convenient and quick, and the fixed connection effect is good. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the end plate, such as the top plate, at the other end of the connecting structure of this utility model (viewed from the outside in).

[0015] Figure 2 This is a front view schematic diagram of the steel cage connecting structure of this utility model.

[0016] Figure 3 This is a schematic diagram of the end plate, such as the bottom end plate, of the connection structure of this utility model.

[0017] Figure 4 This is the first embodiment. Figure 1 An enlarged structural diagram showing the end plate at the other end with a longitudinally cut axial through hole that mates with a stepped threaded sleeve and is in a fixed connection state.

[0018] Figure 5 yes Figure 4 A schematic diagram of the exploded structure, showing the top of the non-prestressed steel reinforcement (omitted drawing).

[0019] Figure 6 yes Figure 5 A schematic diagram of the exploded structure is shown, along with the bottom end of the anchoring steel bars of the foundation (omitted drawing).

[0020] Figure 7 This is the second embodiment. Figure 1 An enlarged structural diagram showing the end plate at the other end with a longitudinally cut axial through hole that mates with a stepped threaded sleeve and is in a fixed connection state.

[0021] Figure 8 yes Figure 7 A schematic diagram of the exploded structure is shown, along with the bottom end of the anchoring steel bars of the foundation (omitted drawing).

[0022] Figure 9 yes Figure 3 An enlarged and exploded structural diagram showing an axial through hole longitudinally cut into an end plate at one end, which mates with a non-prestressed steel bar at the bottom end.

[0023] As shown in the figure:

[0024] 1. Precast concrete piles;

[0025] 2. End plate; 21. End plate at one end; 211. Third straight cylindrical internal thread hole; 2111. Third internal thread; 22. End plate at the other end; 221. Stepped hole; 2211. Small diameter hole; 2212. Large diameter hole; 2213. Axial limiting surface; 23. Through hole for prestressed steel bars; 24. Second center hole.

[0026] 31. Prestressed steel bar; 32. Non-prestressed steel bar; 321. Fourth external thread; 322. First external thread; 323. Upset head; 33. Spiral stirrup.

[0027] 4. Stepped threaded sleeve; 41. Small diameter section; 42. Large diameter section; 43. Stepped surface; 44. Force application hole; 45. First cylindrical internal threaded hole; 451. First internal thread; 46. First stepped threaded sleeve; 47. Second stepped threaded sleeve; 471. Second external thread.

[0028] 5. Axial clearance;

[0029] 6. Anchoring reinforcement; 61. Third external thread;

[0030] 7. Connecting sleeve; 71. First center hole; 72. Snap ring; 73. Second straight cylindrical internal thread hole; 731. Second internal thread. Detailed Implementation

[0031] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. It should be noted that these descriptions of specific embodiments are intended to aid in understanding this utility model, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various specific embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0032] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown.

[0033] Precast concrete piles 1 in the prior art generally include end plates 2 at both ends, and multiple prestressed steel bars 31 running through the entire length of the precast concrete pile 1. The multiple prestressed steel bars 31 are arranged circumferentially. If they are evenly arranged circumferentially, the end of each prestressed steel bar 31 is fixed to its respective end plate 2. If they pass through prestressed steel bar through holes 23 on the end plates 2, they are fixed by their respective end caps. The prestressed steel bar through holes 23 can be roughly gourd-shaped holes. The larger hole of the gourd-shaped hole allows the prestressed steel bar 31 to pass through, while the smaller hole of the gourd-shaped hole axially limits the prestressed steel bar 31; this is also called a tensioning hole. At least one end of the multiple prestressed steel bars 31 is a tensioning end. Tensioning one of the end plates 2 allows tensioning of the multiple prestressed steel bars 31. The precast concrete pile 1 is also called a precast concrete pile.

[0034] The precast concrete pile 1 can be a precast pipe pile as shown in the figure, which includes a second central hole 24 and second central holes 24 on both end plates 2. It can also be a precast solid pile not shown in the figure. The precast concrete pile 1 can be a circular pile or a square pile, etc.

[0035] In practical applications, some precast concrete piles 1 equipped with prestressed steel bars 31, such as those used for tension piles, require enhanced strength and mechanical properties. Therefore, they typically include multiple non-prestressed steel bars 32. These non-prestressed steel bars 32 can be arranged circumferentially or evenly. The number of non-prestressed steel bars 32 can be equal to or unequal to the number of prestressed steel bars 31; for example, the number of non-prestressed steel bars 32 can be less or more than the number of prestressed steel bars 31. The diameter of the non-prestressed steel bars 32 within the same precast concrete pile 1 is generally smaller than the diameter of the prestressed steel bars 31. It is easy to understand that the precast concrete pile 1 also includes spiral stirrups 33. These spiral stirrups 33 can be lapped and bound to all prestressed and non-prestressed steel bars 31 to form a reinforcing cage, but they are generally not connected to the end plates 2. Annular stirrups may also be included, with each end plate fixedly connected to its respective end plate 2, such as by welding.

[0036] An embodiment of the connection structure between the non-prestressed steel bars and the end plate of the precast concrete pile of this utility model, as described above, includes multiple non-prestressed steel bars 32 arranged along the circumference of the end plate 2.

[0037] Each non-prestressed steel bar 32 extends through the entire length of the precast concrete pile 1. One end of each non-prestressed steel bar 32 is fixedly connected to an end plate 21. The other end of each non-prestressed steel bar 32 is connected to a stepped threaded sleeve 4 with a larger outer end and a smaller inner end. The end plate 22 at the other end has multiple axial through holes for sliding the small diameter section 41 of the stepped threaded sleeve 4, namely the small diameter holes 2211 described below. The end plate 22 at the other end also has an axial limiting surface 2213 for axially limiting the stepped threaded sleeve 4 after the multiple prestressed steel bars 31 are tensioned, so that each non-prestressed steel bar 32 is rigidly fixedly connected to the end plate 2. Before the multiple prestressed steel bars 31 are tensioned, there is an axial gap 5 between the stepped surface 43 of the stepped threaded sleeve 4 and the axial limiting surface 2213 of the end plate 22 at the other end for tensioning.

[0038] See Figure 4 , Figure 5 and Figure 6 In the first embodiment, the other end of each non-prestressed steel bar 32 is connected to a stepped threaded sleeve 46 with a larger outer end and a smaller inner end: the first stepped threaded sleeve 46 has a first cylindrical internal threaded hole 45, and the other end of each non-prestressed steel bar 32 has a first external thread 322 for tightening with the internal thread 451 of the first cylindrical internal threaded hole 45. The other end of each non-prestressed steel bar 32 has a first external thread 322, which engages with a first stepped threaded sleeve 46 with a larger outer end and a smaller inner end. It is easy to understand that after the end plate 21 at one end of the non-prestressed steel bar 32 is fixed to the lower end plate, the first internal thread 451 at the lower end of the first cylindrical internal thread hole 45 on the first stepped threaded sleeve 46 is tightened with the first external thread 322 at the top end of the non-prestressed steel bar 32. The stepped surface 43 of the first stepped threaded sleeve 46 is axially limited by the axial limiting surface 2213 in the stepped hole 221 of the other end plate 22, thereby rigidly connecting both ends of the non-prestressed steel bar 32 to the end plates 2. The first internal thread 451 at the upper end of the first cylindrical internal thread hole 45 on the first stepped threaded sleeve 46 can be used to tighten the lower end of the anchoring steel bar 6. If it is tightened with the third external thread 61, and the anchoring steel bar 6 can abut against the top end surface of the non-prestressed steel bar 32, the axial limitation of the non-prestressed steel bar 32 is further improved, making the technical effect of rigidly connecting both ends of the non-prestressed steel bar 32 to the end plates 2 even better.

[0039] See Figure 7 and Figure 8In a second embodiment, the other end of each non-prestressed steel bar 32 is connected to a stepped threaded sleeve 4 with a larger outer end and a smaller inner end. The small-diameter section 41 of the second stepped threaded sleeve 47 has a second external thread 471. The other end of each non-prestressed steel bar 32 passes through a first central hole 71 of a connecting sleeve 7. The end of the other end of each non-prestressed steel bar 32 has a notched head 323 axially limited by a retaining ring 72 of the connecting sleeve 7. The connecting sleeve 7 has a second internal thread 731 in a second straight cylindrical internal threaded hole 73 for tightening with the second external thread 471 of the small-diameter section 41 of the second stepped threaded sleeve 47. It is easy to understand that the second stepped threaded sleeve 47 also has a first straight cylindrical internal threaded hole 45. After the end plate 21 of one end of the non-prestressed steel bar 32 is fixed as the lower end plate, the second external thread 471 of the small diameter section 41 of the second stepped threaded sleeve 47 is tightened with the second internal thread 731 of the second straight cylindrical internal thread hole 73 of the connecting sleeve 7. At this time, the non-prestressed steel bar 32 is tightened and the outer end face of the second stepped threaded sleeve 47 can be pressed against the inner end face of the end plate 22 at the other end. Of course, a gap can also be left. At the same time, the step surface 43 of the second stepped threaded sleeve 47 is axially limited by the axial limiting surface 2213 in the step hole 221 of the end plate 22 at the other end, so that the two ends of the non-prestressed steel bar 32 are rigidly fixedly connected to the two end plates 2. The entire length of the first cylindrical internal threaded hole 45 on the second stepped threaded sleeve 47 is available for tightening the lower end of the anchoring steel bar 6. If it is tightened with the third external thread 61, the anchoring steel bar 6 can abut against the top surface of the upset head 323 of the non-prestressed steel bar 32, further limiting the axial movement of the non-prestressed steel bar 32, so that the two ends of the non-prestressed steel bar 32 are rigidly fixed to the two end plates 2, which improves the technical effect.

[0040] The connection structure between the top end of the non-prestressed steel bar 32 of the topmost precast concrete pile 1, which is composed of multiple precast concrete piles 1, and the top end plate can adopt the connection structure between the other end of the non-prestressed steel bar 32 and the other end plate 22. A portion of the first straight cylindrical internal threaded hole 45 of the stepped threaded sleeve 4, such as the first internal thread 451 of the first straight cylindrical internal threaded hole 45 of the first stepped threaded sleeve 46, or the entire portion, such as the first internal thread 451 of the entire first straight cylindrical internal threaded hole 45 of the second stepped threaded sleeve 47, is used to screw and fix the third external thread 61 of the lower end of the anchoring steel bar 6 of the pile cap of the pull-out pile.

[0041] It is easy to understand that, due to the rigid nature of the non-prestressed steel bar 32, after tightening and straightening, both ends of the non-prestressed steel bar 32 are fixedly connected to their respective end plates 2. Before tensioning multiple prestressed steel bars 31, the stepped surface 43 of the stepped threaded sleeve 4 and the axial limiting surface 2213 of the end plate 22 at the other end are left with an axial gap 5 for tensioning.

[0042] It is easy to understand that the circle containing the multiple non-prestressed steel bars 32 can be the inner circle. That is, the diameter of the circle containing the multiple non-prestressed steel bars 32 on the end plate 2, such as the first circle, is smaller than the diameter of the circle containing the prestressed steel bars 31, such as the second circle. This makes the arrangement of the holes on the end plate 2 more reasonable and is more conducive to the tensioning of the prestressed steel bars 31 and the operation of fixing the non-prestressed steel bars 32 to the end plate 2. Neither the first circle nor the second circle is shown in the figure.

[0043] The non-prestressed steel bar 32 is fixedly connected to the end plate 21 at one end, such as the bottom end plate. This connection can be achieved by tightening the fourth external thread 321 at one end of each non-prestressed steel bar 32 with the third internal thread 2111 of the third straight cylindrical internal thread hole 211 of the end plate 21 at one end.

[0044] The axial through hole 221 on the end plate 22 at the other end is a stepped hole 221 for the axial sliding of the stepped threaded sleeve 4. The axial limiting surface 2213 refers to the stepped limiting surface of the large-diameter hole 2212 at the outer end of the stepped hole 221. The large-diameter hole 2212 is also called the axial through hole. That is, the large-diameter section 42 slides axially in the large-diameter hole 2212, and the small-diameter section 41 slides axially in the small-diameter hole 2211. It is easy to understand that the stepped surface 43 of the stepped threaded sleeve 4 and the axial limiting surface 2213 of the stepped hole 221, i.e., the stepped limiting surface, restrict the stroke of the large-diameter section 42 in the large-diameter hole 2212. It is easy to understand that the small-diameter section 41 of the first stepped threaded sleeve 46 that slides in the small-diameter hole 221 is a smooth section; the small-diameter section 41 of the second stepped threaded sleeve 47 that slides in the small-diameter hole 221 is a threaded section, i.e., the second external thread 471 section.

[0045] Before tensioning, an axial gap 5 is left between the stepped surface 43 of each stepped threaded sleeve 4 and the axial limiting surface 2213 of the end plate 22 at the other end, i.e., the stepped limiting surface, for tensioning purposes. The axial gap 5 can be greater than the actual tensioning distance of the prestressed steel bar 31. Of course, if the adjustment is precise, the axial gap 5 can be equal to the actual tensioning distance of the prestressed steel bar 31. But generally it is greater. Tightening the stepped threaded sleeve 4 after the prestressed steel bar 31 is tensioned is easier to operate and more reliable. The outer end of each stepped threaded sleeve 4 has a force-applying structure for applying force with a wrench to tighten the stepped threaded sleeve 4 to the other end of each non-prestressed steel bar 32, thereby fixing the non-prestressed steel bar 32 to the end plate 2. Such as a force-applying hole 44, the force-applying structure can also be a protruding column or a cylindrical screw nut, etc. An F-shaped wrench can be used. The longitudinal bar of the F-shaped wrench is a lever for easy application of force. The front ends of the two wrench heads formed by the two crossbars can be inserted into the force application hole 44 of each stepped threaded sleeve 4 to tighten or loosen the second external thread 322 and the first internal thread 451 at the other end of the stepped threaded sleeve 4 relative to the non-prestressed steel bar 32, or relative to the second external thread 471 or the second internal thread 731, which is labor-saving, quick and reliable.

[0046] The specific embodiments of the connection structure between the non-prestressed steel reinforcement and the end plate of the precast concrete pile of this utility model are subject to variation. The axial limiting surface, as described above, can also be the outer end face or top face of the other end plate, such as the top end plate. The wrench can also be an electric wrench, with its two wrenches extending into two symmetrically arranged force application holes 44. The fixed connection between the end plate at one end and the non-prestressed steel reinforcement at the bottom end, as described above, can also be achieved by axial limiting of the pier head and the end plate hole with a retaining ring that can be interference-fitted with the hole, or by welding after passing through the bottom end plate, etc.

[0047] It's easy to understand that using terms like "first," "second," and "third" is for ease of description and doesn't necessarily indicate their importance. A straight-tube internally threaded hole is also called an internally threaded hole.

[0048] The diameter of the anchoring rebar can be equal to or greater than that of the non-prestressed rebar, and can be reduced in diameter by the anchoring rebar connector. For example, a connecting threaded post with external threads can be used, whose outer diameter and thread size are the same as the diameter and thread size of the second external thread at the top of the non-prestressed rebar. However, the anchoring rebar connector that engages at the top can be a stepped threaded hole, that is, the lower end of the anchoring rebar connector uses a small-diameter internal thread, while the upper end can use a large-diameter internal thread. The small-diameter internal thread engages with the connecting threaded post, and the large-diameter internal thread can engage with the large-diameter external thread at the lower end of the large-diameter anchoring rebar of the foundation.

[0049] Components, structures, or quantities not marked above are not shown in the drawings, and some components are not marked in the drawings. The drawings are for illustrative purposes only. In case of any inconsistency between the drawings and the text description, or between the drawings themselves, the text description shall prevail.

[0050] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A connection structure between non-prestressed steel bars and an end plate of a precast concrete pile, comprising multiple non-prestressed steel bars arranged along the circumference of the end plate, characterized in that: Each non-prestressed steel bar runs through the entire length of the precast concrete pile; one end of each non-prestressed steel bar is fixedly connected to an end plate; the other end of each non-prestressed steel bar is connected to a stepped threaded sleeve with a larger outer end and a smaller inner end. The end plate at the other end has multiple axial through holes for the sliding of the small-diameter section of the stepped threaded sleeve. The end plate at the other end also has an axial limiting surface that limits the axial movement of the stepped threaded sleeve after the multiple prestressed steel bars are tensioned, so that each non-prestressed steel bar is rigidly fixed to the end plate. Before the multiple prestressed steel bars are tensioned, there is an axial gap between the stepped surface of the stepped threaded sleeve and the axial limiting surface of the end plate at the other end for tensioning purposes.

2. The connection structure between the non-prestressed steel reinforcement and the end plate of the precast concrete pile according to claim 1, characterized in that: The first stepped threaded sleeve is provided with a first cylindrical internal thread hole, and the other end of each non-prestressed tendon is provided with a first external thread for tightening with the internal thread of the first cylindrical internal thread hole.

3. The connection structure between the non-prestressed steel reinforcement and the end plate of the precast concrete pile according to claim 1, characterized in that: The small-diameter section of the second stepped threaded sleeve is provided with a second external thread. The other end of each non-prestressed steel bar passes through the first central hole of a connecting sleeve. The other end of each non-prestressed steel bar has an upsetting head that is axially limited by the retaining ring of the connecting sleeve. The connecting sleeve has an internal thread of a second straight cylindrical internal thread hole for tightening with the second external thread of the small-diameter section of the second stepped threaded sleeve.

4. The connection structure between the non-prestressed steel reinforcement and the end plate of the precast concrete pile according to claim 1, characterized in that: The axial through hole on the end plate at the other end is a stepped hole for axial sliding of the stepped threaded sleeve. The inner end of the stepped hole is a small-diameter hole for axial sliding of the small-diameter section of the stepped threaded sleeve, and the outer end of the stepped hole is a large-diameter hole for axial sliding of the large-diameter section of the stepped threaded sleeve. The axial limiting surface refers to the stepped limiting surface that limits the stepped surface of the stepped threaded sleeve.

5. The connection structure between the non-prestressed steel reinforcement and the end plate of the precast concrete pile according to claim 1, characterized in that: The axial gap is greater than the actual tensioning distance of the prestressed steel bars. Each stepped threaded sleeve has an external force-applying structure at its outer end for applying force with a wrench to tighten the stepped threaded sleeve to the other end of each non-prestressed steel bar, thereby fixing the non-prestressed steel bar to the end plate.

6. The connection structure between the non-prestressed steel reinforcement and the end plate of the precast concrete pile according to claim 1, characterized in that: The connection structure between the top end of the non-prestressed steel bar of the top section of the precast concrete pile, which is composed of multiple precast concrete piles, and the top end plate adopts the connection structure between the other end of the non-prestressed steel bar and the other end plate; the internal threads of part or all of the first straight cylindrical internal thread hole of the stepped threaded sleeve are used to screw and fix the lower end of the anchoring steel bar of the pile cap of the tension-resistant pile with the third external thread.

7. The connection structure between the non-prestressed steel reinforcement and the end plate of the precast concrete pile according to claim 1, characterized in that: The fixed connection between one end of the non-prestressed steel bar and the end plate at the other end means that the fourth external thread at one end of each non-prestressed steel bar is screwed into the third straight cylindrical internal thread hole of the end plate at the other end for a fixed connection.

Images