A prestressed concrete precast pile with end plate and grouting connection
By setting a grouting connection structure on the end plate of the precast pile and using a combination of insert rods and sleeves, the problem of welding connection quality depending on the worker's skill was solved, the corrosion resistance and connection strength of the precast pile were improved, and the safety and construction efficiency of the pile foundation were ensured.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG UNIV
- Filing Date
- 2025-07-07
- Publication Date
- 2026-05-26
AI Technical Summary
The welding quality of existing precast piles with end plates is greatly affected by the workers' skills, and they have poor corrosion resistance, making them unsuitable for use in corrosive environments.
A grouting connection structure is adopted, which uses tensioning holes and connecting components on the end plate, and a combination of insert rods and sleeves to achieve a firm connection of precast piles and improve corrosion resistance.
This improves the connection strength and corrosion resistance of precast piles, ensuring the safety and construction efficiency of the pile foundation.
Smart Images
Figure CN224281249U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of precast pile technology, specifically to a grout-connected prestressed concrete precast pile with end plate. Background Technology
[0002] Precast concrete piles have advantages such as high structural strength and high construction efficiency, and are widely used in building foundation construction. In building pile foundation design, a relatively deep pile foundation is required to ensure the stability of the superstructure. The length of a single precast pile generally does not reach the designed depth, so multiple precast piles need to be connected end-to-end and driven downwards until the designed depth is reached.
[0003] Precast concrete piles can be divided into two types based on the pile head structure: precast piles with end plates and precast piles without end plates. Each of these two structures has its own advantages and disadvantages. The advantage of precast piles with end plates is that the pile head has high strength and is not easy to break during construction, and the end plates disperse the stress at the joint, avoiding stress concentration. In addition, adjacent pile heads are connected by welding the end plates, which is a simple process. However, the quality of the end plate welding is greatly affected by the skill of the workers, and the welding has high requirements for the construction environment. Construction cannot be carried out in windy or rainy weather. Therefore, piles with welded end plates have low corrosion resistance and cannot be used in corrosive environments. Utility Model Content
[0004] This invention addresses the shortcomings of existing technologies by proposing a grout-connected prestressed concrete precast pile with end plates that features a simple structure and more accurate connection positioning. By incorporating a grout-connected structure on the end plates, the strength of the precast pile head is ensured while improving the corrosion resistance of the pile foundation. Even if the weld on the outer side of the end plate is corroded, the grout-fixed connection structure still guarantees a firm connection between the two pile sections, thus enhancing the safety of the pile foundation.
[0005] This utility model is achieved through the following technical solution:
[0006] A grout-connected prestressed concrete precast pile with end plate includes prestressed steel bars, a concrete pile body, end plates, and connecting components installed on the end plates. The prestressed steel bars are disposed in the concrete pile body, and the end plates are disposed at both ends of the concrete pile body.
[0007] The end plate is provided with tensioning holes, which include mounting holes, extrusion holes and connecting holes. The inner wall of the mounting hole is threaded, the inner wall of the extrusion hole is frustum-shaped, and the inner diameter of the frustum is larger on the outside and smaller on the inside. The connecting hole connects the mounting hole and the extrusion hole. The end of the prestressed steel bar is upset and fixed in the extrusion hole.
[0008] The connecting assembly includes a plug and a sleeve;
[0009] The sleeve is open at one end and is embedded in the concrete pile body. The opening of the sleeve is connected to the mounting hole.
[0010] The insertion rod includes an insertion section and a fixing section. The insertion rod is threadedly connected to the mounting hole of the end plate of another grouting prestressed concrete precast pile with end plate through the fixing section. The insertion section of the insertion rod is inserted into the open end of the sleeve filled with connecting grout.
[0011] As a further improvement of this utility model, the insertion section of the plug is provided with flanges that are evenly spaced along the extension direction.
[0012] As a further improvement of this utility model, it also includes anchoring steel bars, one end of which is fixedly connected to the end plate, and the other end is inserted into the concrete pile body.
[0013] As a further improvement of this utility model, the cross-section of the concrete pile is circular or square.
[0014] As a further improvement of this utility model, the concrete pile body is a solid pile body or a hollow pile body.
[0015] As a further improvement of this utility model, the end plate is provided with a thickened area, and the tensioning hole is disposed on the thickened area.
[0016] As a further improvement of this utility model, the end plate is also provided with a threaded through hole, the opening of the sleeve is connected to the threaded through hole, and the installation and connection of the connecting component is completed through the threaded through hole.
[0017] As a further improvement of this utility model, the threaded through hole is provided on the thickened area.
[0018] Compared with the prior art, the beneficial effects of this utility model are as follows: it retains the advantages of precast piles with end plates, the end plates protect the pile head of the concrete pile body, and the grouting connection structure composed of the insert rod and sleeve improves the connection strength between piles, making it an alternative connection method to end plate welding, and improving the corrosion resistance of precast piles. Attached Figure Description
[0019] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0020] Figure 1This is an overall structural diagram of the prestressed concrete precast pile with end plate and grouting connection according to this utility model.
[0021] Figure 2 This is a schematic diagram of the end plate connection of the prestressed concrete precast pile with end plate for grouting connection according to this utility model;
[0022] Figure 3 This is a schematic diagram of the precast pile connection method of the first embodiment of the prestressed concrete precast pile with end plate and grouting connection of this utility model;
[0023] Figure 4 This is a structural diagram of the end plate of the first embodiment of the prestressed concrete precast pile with end plate and grouting connection of this utility model;
[0024] Figure 5 This is a structural diagram of the connection component of the prestressed concrete precast pile with end plate for grouting connection according to this utility model.
[0025] Figure 6 This is a schematic diagram of the concrete pile manufacturing process of the first embodiment of the prestressed concrete precast pile with end plate and grouting connection of this utility model.
[0026] Figure 7 This is a schematic diagram of the tension nut connection of the first embodiment of the prestressed concrete precast pile with end plate and grouting connection of this utility model;
[0027] Figure 8 This is a schematic diagram of the tension nut connection of the second embodiment of the prestressed concrete precast pile with end plate and grouting connection of this utility model;
[0028] Figure 9 This is a schematic diagram of the connection component of the prestressed concrete precast pile with end plate for grouting connection according to this utility model.
[0029] Figure 10 This is a structural diagram of the tensioning hole of the prestressed concrete precast pile with end plate and grouting connection according to this utility model.
[0030] Figure 11 This is a structural diagram of the end plate of the second embodiment of the prestressed concrete precast pile with end plate and grouting connection of this utility model. Detailed Implementation
[0031] The technical solutions of various embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0032] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.
[0033] First Embodiment
[0034] A grout-connected prestressed concrete precast pile with end plates includes prestressed steel bars 1, a concrete pile body 2, end plates 3, and connecting components installed on the end plates 3. The prestressed steel bars 1 are disposed inside the concrete pile body 2, and the end plates 3 are disposed at both ends of the concrete pile body 2.
[0035] The end plate 3 is provided with tensioning holes 4, which include mounting holes 5, extrusion holes 6 and connecting holes 7. The inner wall of the mounting hole 5 is provided with threads, the inner wall of the extrusion hole 6 is in the shape of a frustum, and the inner diameter of the frustum is larger on the outside and smaller on the inside. The connecting hole 7 connects the mounting hole 5 and the extrusion hole 6. The end of the prestressed steel bar 1 is in the shape of an upsetting head and is fixed in the extrusion hole 6.
[0036] The connecting assembly includes a plug rod 8 and a sleeve 10. The sleeve 10 is open at one end and is embedded in the concrete pile 2. The opening of the sleeve 10 is connected to the mounting hole 5.
[0037] The insert rod 8 includes an insertion section 11 and a fixing section 12. During connection, firstly, a prestressed concrete pile with end plates and grouting connection is inserted into the pile hole with the sleeve 10 facing upwards, and the sleeve 10 and the corresponding mounting hole 5 are filled with connecting grout. Secondly, the insert rod 8 is installed in the mounting hole 5 of the end plate 3 of the second prestressed concrete pile with end plates and grouting connection, and the insert rod 8 is connected to the first prestressed concrete pile with end plates and grouting connection downwards, so that the insert rod 8 is inserted into the sleeve 10 of the first prestressed concrete pile with end plates and grouting connection. At this time, since the connecting grout has not yet solidified, it can well accommodate the insertion section 11 of the insert rod 8. After the connecting grout has completely solidified, the insert rod 8 can be fixed in the sleeve 10. After the insertion of the insert rod 8 into the sleeve 10 is completed, the end plates 3 of the two prestressed concrete piles with end plates and grouting connection can be welded without waiting for the connecting grout to completely solidify, which improves the construction speed. The bonding grout can be made of concrete slurry with low sand and gravel content, or a grout mixed with grouting material, or other adhesives.
[0038] The insertion section 11 of the insert rod 8 is provided with uniformly spaced flanges 12 along the extension direction. When the insert rod 8 is inserted into the sleeve 10 and is wrapped by the connecting slurry, the flanges 12 can enhance the contact between the insertion section 11 of the insert rod 8 and the connecting slurry and increase the resistance of the insert rod 8 to detach from the sleeve 10.
[0039] In this embodiment, an anchoring steel bar 13 is also included. One end of the anchoring steel bar 13 is fixedly connected to the end plate 3, and the other end is inserted into the concrete pile 2. The anchoring steel bar 13 is pre-embedded in the concrete pile 2, which improves the connection strength between the concrete pile 2 and the end plate 3.
[0040] In this embodiment, the concrete pile 2 is a circular hollow pile, the prestressed steel bars 1 are set inside the concrete pile 2, the two end plates 3 are arc-shaped and retain the same number of tensioning holes 4 as the prestressed steel bars 1, and are arranged circumferentially according to the arrangement of the prestressed steel bars 1.
[0041] In other embodiments, the cross-section of the concrete pile 22 may also be square or other shapes.
[0042] In other embodiments, the concrete pile 22 may also be a solid pile.
[0043] In this embodiment, the end plate 3 has a thickened area, and the tensioning hole 4 is located on the thickened area. In order to prevent the end plate 3 from deforming or being damaged during the tensioning process, the end plate 3 is thickened in a local area of the tensioning hole 4.
[0044] The construction method of the grouting-connected prestressed concrete precast pile with end plate in this embodiment includes the following steps:
[0045] S1: Upset both ends of the prestressed steel bar 1, install end plates 3 at both ends of the prestressed steel bar 1, insert the prestressed steel bar 1 and its upset head through the mounting hole 5 and move it to the extrusion hole 6 through the connecting hole 7, and use the edge structure of the extrusion hole 6 to hold the upset head of the prestressed steel bar 1.
[0046] S2: Place the prestressed steel bar 1 and end plate 3 into the bottom template 19, pass the tension nut 17 through the tension plate 18 and screw it into the mounting hole 5, and the end of the tension nut 17 passes through the end plate 3. Set the internal thread corresponding to the tension nut 17 on the inner wall of the sleeve opening 10, and install the sleeve 10 on the end of the tension nut 17 on at least one end plate so that the end face of the sleeve 10 is in close contact with the end plate 3 to prevent concrete liquid from flowing into the sleeve 10 during pouring. Weld the anchor steel bar 13 on the inner side of the end plate 3.
[0047] S3: Pour unformed concrete into the bottom formwork 24, cover with the top formwork, and connect the bottom formwork 24 and the top formwork with bolts. Connect the tensioning device 16 for tensioning. After tensioning, use the bottom formwork 24 and the top formwork to lock the tension force, and remove the tensioning device 16. Hoist the pile body with the formwork still in place onto a centrifuge for concrete centrifugal molding, and then cure it. After the concrete strength reaches the standard, the concrete pile body 2 is formed. Perform prestress release, remove the top formwork and bottom formwork 19, and remove the tensioning plate 18 and tensioning nut 17. Then remove the formwork, allow it to cure for a period of time, and then transport it to the construction site.
[0048] S4: Keep the sleeve 10 facing upwards on the first grouting connected prestressed concrete precast pile with end plate, and construct it from the preset position of the pile to the connection position.
[0049] S5: Pour connecting grout into the sleeve 10 and the corresponding mounting hole 5;
[0050] S6: Install the insert rod 8 in the mounting hole 5 of the end plate 3 of the second grouting connected prestressed concrete precast pile with end plate. If the sleeve 10 is pre-embedded at only one end of the second grouting connected prestressed concrete precast pile with end plate, then the insert rod 8 should be installed at a different end from the sleeve 10.
[0051] S7: Keep the second grout-connected prestressed concrete pile with end plate facing downwards and hoist it above the first grout-connected prestressed concrete pile with end plate.
[0052] S8: Lower the second grouting-connected prestressed concrete pile with end plate so that the insertion rod 8 is inserted into the sleeve 10 of the first grouting-connected prestressed concrete pile with end plate.
[0053] S9: Weld and fix the two end plates 3 at the connection point;
[0054] S10: Continue construction of the second grouting-connected prestressed concrete precast pile with end plate, repeating steps S5-S9 until the pile foundation construction is completed.
[0055] Second Embodiment
[0056] The difference between this embodiment and the first embodiment is that the end plate 3 is also provided with a threaded through hole 15. The opening of the sleeve 10 communicates with the threaded through hole 15, and the tensioning of the prestressed steel bars and the installation of the insertion rod 8 are completed through the threaded through hole 15. Since the connecting hole 7 destroys the integrity of the mounting hole 5, the thread of the mounting hole 5 is incomplete, which may lead to uneven force during tensioning and make the end plate 3 easily damaged. Therefore, a threaded through hole 15 with complete threads is additionally provided on the end plate 3 for both tensioning and subsequent installation of the connecting components.
[0057] In this embodiment, threaded through holes 15 are set on the thickened area and evenly distributed circumferentially. To ensure uniform stress on the prestressed steel bars 1, the pitch circle of the threaded through holes 15 is equal to the pitch circle of the tensioning hole 4. When installing the insertion rod 8, the threaded through holes 15 are used instead of the installation holes 5 for installation. Therefore, the construction method of the grouting-connected prestressed concrete precast pile with end plate in this embodiment differs from that in the first embodiment mainly in the following steps:
[0058] S2: Place the prestressed steel bar 1 and end plate 3 into the bottom template 19, pass the tension nut 17 through the tension plate 18 and screw it into the threaded through hole 15, and the end of the tension nut 17 passes through the end plate 3. Set the internal thread corresponding to the tension nut 17 on the inner wall of the sleeve opening 10, and install the sleeve 10 on the end of the tension nut 17 on at least one end plate so that the end face of the sleeve 10 is in close contact with the end plate 3 to prevent concrete liquid from flowing into the sleeve 10 during pouring. Weld the anchor steel bar 13 on the inner side of the end plate 3.
[0059] S5: Pour connecting grout into the sleeve 10 and the corresponding threaded through hole 15;
[0060] S6: Install the insert rod 8 in the threaded through hole 15 of the end plate 3 of the second grouting connected prestressed concrete precast pile with end plate. If the sleeve 10 is pre-embedded at only one end of the second grouting connected prestressed concrete precast pile with end plate, then the insert rod 8 should be installed at a different end from the sleeve 10.
[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of this utility model.
Claims
1. A prestressed concrete precast pile with end plate and grouting connection, comprising prestressed steel bars, a concrete pile body, an end plate, and a connecting assembly mounted on the end plate, characterized in that: The prestressed steel bars are installed inside the concrete pile, and the end plates are installed at both ends of the concrete pile. The end plate is provided with tensioning holes, which include mounting holes, extrusion holes and connecting holes. The inner wall of the mounting hole is threaded, the inner wall of the extrusion hole is frustum-shaped, and the inner diameter of the frustum is larger on the outside and smaller on the inside. The connecting hole connects the mounting hole and the extrusion hole. The end of the prestressed steel bar is upset and fixed in the extrusion hole. The connecting assembly includes a plug and a sleeve; The sleeve is open at one end and is embedded in the concrete pile body. The opening of the sleeve is connected to the mounting hole. The insertion rod includes an insertion section and a fixing section. The insertion rod is threadedly connected to the mounting hole of the end plate of another grouting prestressed concrete precast pile with end plate through the fixing section. The insertion section of the insertion rod is inserted into the open end of the sleeve filled with connecting grout.
2. The prestressed concrete precast pile with end plate and grouting connection according to claim 1, characterized in that: The insertion section of the insert rod has flanges that are evenly spaced along its extension direction.
3. The prestressed concrete precast pile with end plate and grouting connection according to claim 1, characterized in that: It also includes anchoring steel bars, one end of which is fixedly connected to the end plate, and the other end is inserted into the concrete pile body.
4. The prestressed concrete precast pile with end plate and grouting connection according to claim 1, characterized in that: The concrete pile has a circular or square cross-section.
5. The prestressed concrete precast pile with end plate and grouting connection according to claim 1, characterized in that: The concrete pile can be a solid pile or a hollow pile.
6. The grout-connected prestressed concrete precast pile with end plate according to any one of claims 1-5, characterized in that: The end plate has a thickened area, and the tensioning hole is located on the thickened area.
7. The prestressed concrete precast pile with end plate and grouting connection according to claim 6, characterized in that: The end plate is also provided with a threaded through hole, and the opening of the sleeve communicates with the threaded through hole. The installation and connection of the connecting component are completed through the threaded through hole.
8. The prestressed concrete precast pile with end plate and grouting connection according to claim 7, characterized in that: The threaded through hole is located on the thickened area.