Connecting structure of pile-slab steel seismic joint in pile-slab subgrade

Abstract

The utility model provides a kind of connecting structure of pile plate steel seismic joint in pile plate type roadbed, it is arranged between a pair of prefabricated bridge plate and prefabricated pile, including upper end round steel plate, lower end round steel plate, cross steel, several screw rods, post-cast concrete connecting belt;Lower end round steel plate is fixedly connected with prefabricated pile, upper end round steel plate is arranged at the bottom of post-cast concrete connecting belt and prefabricated bridge plate, the lower end of screw rod is fixed in the top of upper end round steel plate, the upper end of screw rod is poured in post-cast concrete connecting belt;Cross steel includes multiple section bar side support plates and a pair of section bar main support plates, a pair of section bar main support plates are arranged in cross shape, the outer end of section bar main support plate is connected with one section bar side support plate respectively, the upper end of cross steel is connected with upper end round steel plate, the lower end of cross steel is connected with lower end round steel plate.The connecting structure can improve the energy dissipation capacity of pile plate type roadbed, improve the strength degradation stability and the ability of resisting repeated load.

Description

Technical Field

[0001] This utility model relates to the field of pile-slab roadbeds, and more specifically, to a connection structure for a rigid seismic-resistant joint of pile-slab in a pile-slab roadbed. Background Technology

[0002] Pile-slab subgrade is a soilless subgrade structure that falls between roadbed and bridge subgrades, primarily composed of precast piles, precast beams / slabs, and pile-slab joints. Compared to traditional roadbeds, this structure effectively avoids the two major challenges of land acquisition and soil removal, and offers advantages such as good smoothness, minimal post-construction settlement, and suitability for prefabricated construction. In particular, key components such as piles and slabs can be produced industrially and assembled, effectively reducing negative environmental impacts and improving construction efficiency. In this structure, the connection nodes between piles and slabs are crucial for connection and force transmission; their mechanical properties directly affect the overall stability and durability of the subgrade, and are a key factor limiting the full realization of the inherent advantages of this prefabricated subgrade structure.

[0003] For example, the utility model patent with authorization announcement number CN223292884U discloses a pile-slab seismic joint structure, including a post-cast connecting strip connecting adjacent precast road panels and a combined connector set on the precast pile to cooperate with the precast road panels. The combined connector includes a lower end plate connected to a precast pile end plate set on the top surface of the precast pile, and an upper end plate connected to the top of the lower end plate through a precast pipe. Symmetrical screw holes are arranged on the upper end plate, and screw rods are installed in the screw holes. A spring that cooperates with the bottom surface of the upper end plate is sleeved on the screw rod, and the spring cooperates with a bolt set at the bottom end of the screw rod. This pile-slab seismic joint structure can replace the traditional pile-slab connection method of inserting a reinforcing cage and casting in place with concrete by using a post-cast connecting strip and an improved combined connector, while ensuring the load-bearing performance of the pile-slab joint. This can effectively improve the assembly construction efficiency of the pile-slab seismic joint structure connection and reduce the construction cost of the pile-slab seismic joint connection. However, the main stress points of the publicly disclosed pile-slab seismic joint structure are only circular precast pipes, with a small contact area, which means that the energy dissipation capacity, strength degradation stability and ability to resist repeated loads need to be improved. Utility Model Content

[0004] In order to synergistically improve the energy dissipation capacity, strength degradation stability and resistance to repeated loads of pile-slab roadbed, and facilitate construction and maintenance, the technical solution adopted by this utility model is: a connection structure of the pile-slab rigid seismic joint in a pile-slab roadbed, which is set between a pair of precast bridge slabs and precast piles, including an upper circular steel plate, a lower circular steel plate, a cross-shaped steel, several bolts, and a post-cast concrete connecting strip poured between the pair of precast bridge slabs; The lower end circular steel plate is fixedly connected to the precast pile, and the upper end circular steel plate is set at the bottom of the post-cast concrete connecting strip and the precast bridge plate to support the post-cast concrete connecting strip and the precast bridge plate from below. The lower end of the screw is fixed to the top of the upper round steel plate, and the upper end of the screw intersects with the inter-plate connecting steel bars on the precast bridge plate and is cast into the post-cast concrete connecting strip. The cross-shaped steel section includes multiple profile side support plates and a pair of profile main support plates. The pair of profile main support plates are arranged in a cross shape. The outer ends of each profile main support plate are connected to a profile side support plate. The upper and lower ends of the profile main support plates and the profile side support plates are flush. The multiple profile side support plates and the pair of profile main support plates together form a square-shaped hollow column structure with an open cross-section. The upper end of the cross-shaped steel section is connected to the upper round steel plate, and the lower end of the cross-shaped steel section is connected to the lower round steel plate, so that the connection between the precast pile and the pair of precast bridge plates can undergo plastic deformation under continuous load.

[0005] Beneficial effects: Through the coordinated cooperation of multiple profile side support plates, a pair of profile main support plates, upper round steel plate, and lower round steel plate, the stress-bearing area is increased. Furthermore, the multiple profile side support plates and the pair of profile main support plates can be fully connected with the upper and lower round steel plates, giving them good ductility and energy dissipation capacity. This forms a connection that is not rigid in the traditional sense, giving it ductile energy dissipation capacity. Thus, when encountering extreme loads such as earthquakes, the ductile deformation capacity generated by the steel profiles can effectively dissipate seismic energy, thereby delaying or avoiding brittle failure of concrete.

[0006] Based on the above, the profile side support plate is arranged perpendicularly to the profile main support plate, the upper round steel plate is arranged parallel to the lower round steel plate, and the center of the upper round steel plate is arranged vertically to the center of the lower round steel plate. The profile main support plate is arranged vertically between the upper round steel plate and the lower round steel plate.

[0007] Beneficial effects: By setting the profile side support plate perpendicular to the profile main support plate, and setting the profile main support plate perpendicular to the upper round steel plate, the connection between the profile side support plate and the profile main support plate, and between the profile main support plate and the upper round steel plate, can be ensured, and the four can form a stable frame structure, thereby improving the ability to resist deformation.

[0008] Based on the above, the cross-shaped steel is centered between the upper circular steel plate and the lower circular steel plate.

[0009] Beneficial effects: By welding the cross-shaped steel to the upper and lower round steel plates, it can be ensured that the cross-shaped steel, the upper round steel plate, and the lower round steel plate can be evenly stressed, effectively avoiding tilting after being subjected to load.

[0010] Based on the above, a pair of the main support plates of the profile are centrally connected between the multiple side support plates of the profile.

[0011] Beneficial effects: By centering and connecting the main support plate of the profile between multiple side support plates of the profile, the multiple side support plates of the profile can be stably connected together, increasing the ability to resist lateral deformation or breakage.

[0012] Based on the above, the area of ​​the upper circular steel plate is larger than the area of ​​the lower circular steel plate, the diameter of the upper circular steel plate is larger than the width of the post-cast concrete connecting strip, and the post-cast concrete connecting strip is located at the center of the upper circular steel plate, so that the upper circular steel plate can support the bottom of a pair of precast bridge slabs respectively.

[0013] Beneficial effects: By extending the two ends of the upper circular steel plate beyond the post-cast concrete connecting strip and making it extend to the bottom of the pair of precast bridge slabs, it is possible to ensure that the precast bridge slabs and the upper circular steel plate have a certain overlap. The upper circular steel plate can be used to support the precast bridge slabs, thereby improving the deformation resistance of the connection structure.

[0014] Based on the above, the support length of the upper circular steel plate for the post-cast concrete connecting strip on each side is greater than or equal to 150mm.

[0015] Beneficial effects: By further limiting the support length of the upper circular steel plate to the post-cast concrete connecting strip on each side, it is possible to ensure that the upper circular steel plate forms a stable support for the precast bridge deck, avoiding the defect of insufficient support force due to insufficient length.

[0016] Based on the above, the side length of the inscribed quadrilateral of the lower circular steel plate is greater than the side length of the cross-shaped steel, so that the cross-shaped steel can be fully welded when welded to the lower circular steel plate.

[0017] Beneficial effects: By further defining the dimensional fit between the cross-shaped steel and the lower round steel plate, it is easier to weld the cross-shaped steel onto the lower round steel plate, and it also ensures that the cross-shaped steel can be fully welded onto the lower round steel plate, thereby improving the connection strength between the two.

[0018] Based on the above, the specifications of the multiple profile side support plates are the same, the specifications of the pair of profile main support plates are the same, and the length of the profile side support plate is less than the length of the profile main support plate.

[0019] Beneficial effects: By limiting the side support plates of the profile to have the same specifications, the main support plates of the profile can be designed to have the same specifications, thereby achieving consistency of parts and facilitating assembly and maintenance.

[0020] Based on the above, the upper circular steel plate has several bolt holes, and the screw is fixed in the bolt holes by nuts. The screws are distributed on a virtual circle with the same center as the upper circular steel plate.

[0021] Beneficial effects: By using a nut to connect the screw to the upper circular steel plate, the amount of welding on the upper circular steel plate can be reduced, thus decreasing the deformation of the upper circular steel plate caused by welding heat. Simultaneously, by limiting the installation position of the screw, a uniform connection between the screw and the post-poured concrete strip can be ensured.

[0022] Based on the above, the top of the precast pile is provided with a pile end plate for connecting the lower circular steel plate. The diameter of the pile end plate and the diameter of the lower circular steel plate are the same as the diameter of the precast pile, so that the pile end plate, the lower circular steel plate and the precast pile can be welded together across the entire cross section.

[0023] Beneficial effects: By limiting the dimensional relationship between the pile end plate, the lower circular steel plate and the precast pile, it is possible to ensure that the welding contact area of ​​the three is increased during welding, thereby improving the structural strength and connection stability.

[0024] This utility model has substantial features and advancements compared to existing technologies. Specifically, the connection structure of the pile-slab rigid seismic joint in the pile-slab roadbed provided by this utility model selects cross-shaped steel and bolts of a certain length as the main load-bearing and force-transmitting components. The cross-shaped steel is designed as a main support plate structure consisting of two sets of cross-shaped intersecting profiles, with profile side support plates connected to the outside of the main support plates. Multiple profile side support plates form a grid-shaped hollow columnar structure with corner openings in the cross section. This increases the load-bearing area while reserving sufficient deformation space at the corners of the multiple profile side support plates. By comprehensively utilizing the good ductility and energy dissipation capacity of the cross-shaped steel and bolts, a connection that is not rigid in the traditional sense is formed. Ultimately, this connection structure has good ductile energy dissipation capacity, so that when encountering extreme loads such as earthquakes, the ductile deformation capacity generated by the cross-shaped steel can effectively dissipate seismic energy, delaying or avoiding brittle failure of concrete.

[0025] Specifically, a quasi-static performance test was conducted compared with the scheme described in the background art. The test data shows that the connection structure provided by this invention has a larger hysteresis curve area, demonstrating its stronger energy dissipation capacity and a maximum bearing capacity of 79.30 kN, while the existing scheme's maximum bearing capacity is only 60.25 kN. Furthermore, the average peak displacement of the connection structure provided by this invention is 15.70 mm higher than that of existing specimens, an increase of approximately 22.36%, indicating better toughness and improved deformation capacity to a certain extent. Simultaneously, the final cumulative energy dissipation of the connection structure provided by this invention is approximately 58.2% higher than that of existing node specimens, thus confirming that the connection structure of the pile-slab rigid seismic joint in the pile-slab subgrade provided in this embodiment can synergistically improve the energy dissipation capacity, strength degradation stability, and resistance to repeated loads of the pile-slab subgrade. It is also convenient for construction and maintenance.

[0026] Furthermore, when the bolts are fixedly connected to the post-cast concrete connecting strip, the bolts penetrate the upper circular steel plate and extend into the post-cast reinforced concrete area. They are anchored to the post-cast concrete connecting strip between adjacent precast slabs, achieving a tight connection with the superstructure. The lower circular steel plate is welded to the pile end plate at the top of the precast pile, thus realizing an effective overall connection between the upper precast bridge slab structure and the lower precast pile.

[0027] Furthermore, the diameter of the upper circular steel plate is designed to be larger than the width of the post-cast concrete connecting strip, ensuring that both ends of the upper circular steel plate overlap with the precast bridge deck. This ensures that the support length of the node on the precast bridge deck is not less than 150mm, which helps to enhance the overall stability of the connection structure between the precast bridge deck and the precast piles. It also reduces the shear force borne by the post-cast concrete connecting strip through stress diffusion, thereby extending the service life of the structure.

[0028] Furthermore, through the bolt holes in the upper circular steel plate, the bolt passes through the upper circular steel plate and extends to the post-poured concrete connection area. It is anchored to the concrete to achieve a tight connection between the node and the superstructure. When the node is subjected to dynamic loads, the bond force between the bolt and the post-poured concrete connection can restrain the cracking and deformation of the post-poured concrete connection, thereby improving the integrity and reliability of the node.

[0029] Furthermore, the lower circular steel plate has a circular cross-section with a diameter consistent with that of the precast pile to ensure cross-sectional continuity and effective load transfer.

[0030] Furthermore, the outer contour dimension of the cross-shaped steel is smaller than the dimension of the inscribed quadrilateral of the lower circular steel plate, so as to ensure that the steel can be reasonably arranged in the plate and that welding positions are reserved.

[0031] Furthermore, the connection structure of the pile-slab rigid seismic joint in this pile-slab roadbed can be prefabricated in a standardized factory, which greatly improves the construction quality and efficiency, and facilitates future inspection and replacement after damage. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of the connection structure of the pile-slab rigid seismic-resistant node in the pile-slab roadbed provided by this utility model.

[0033] Figure 2 This is a partial structural diagram of the connection structure of the pile-slab rigid seismic-resistant node in the pile-slab roadbed provided by this utility model.

[0034] Figure 3 This is a schematic diagram of the transverse cross-section of the connection structure of the pile-slab rigid seismic-resistant node in the pile-slab roadbed provided by this utility model.

[0035] Figure 4 This is a longitudinal cross-sectional schematic diagram of the connection structure of the pile-slab rigid seismic-resistant node in the pile-slab roadbed provided by this utility model.

[0036] Figure 5 shows the test hysteresis curve of the connection structure of the pile-slab rigid seismic-resistant joint in the pile-slab roadbed provided by this utility model.

[0037] Figure 6 shows the test energy dissipation capacity curve of the connection structure of the pile-slab rigid seismic-resistant joint in the pile-slab roadbed provided by this utility model.

[0038] Figure 7 The test strength degradation curve of the connection structure of the pile-slab rigid seismic joint in the pile-slab roadbed provided by this utility model.

[0039] Figure 8 shows the hysteresis curves of the pile-slab seismic joint structure test in the comparative scheme.

[0040] Figure 9 This is a comparison diagram of the structural skeleton curves of the pile-slab seismic joint in this utility model and the comparative scheme.

[0041] Figure 10 This is a comparison curve of the energy dissipation capacity of the pile-slab seismic joint structure in this utility model and the comparative scheme.

[0042] In the diagram: 1. Post-cast concrete connecting strip; 2. Precast bridge slab; 3. Upper round steel plate; 4. Screw rod; 5. Cross-shaped steel; 6. Main support plate of profile; 7. Lower round steel plate; 8. Precast pile; 9. Bolt hole; 10. Combined connector; 11. Inter-slab connecting reinforcement; 12. Pile end plate; 13. Side support plate of profile. Detailed Implementation

[0043] The technical solution of this utility model will be further described in detail below through specific embodiments.

[0044] Example 1 This embodiment provides a connection structure for a rigid seismic-resistant pile-slab joint in a pile-slab roadbed, such as... Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, it is set between a pair of precast bridge slabs 2 and precast piles 8. It includes an upper circular steel plate 3, a lower circular steel plate 7, a cross-shaped steel 5, several bolts 4, and a post-cast concrete connecting strip 1 poured between the pair of precast bridge slabs 2.

[0045] The lower circular steel plate 7 is fixedly connected to the precast pile 8, and the upper circular steel plate 3 is set at the bottom of the post-cast concrete connecting strip 1 and the precast bridge slab 2 to support the post-cast concrete connecting strip 1 and the precast bridge slab 2 from below.

[0046] The lower end of the screw 4 is fixed to the top of the upper round steel plate 3, and the upper end of the screw 4 intersects with the inter-plate connecting steel bar 11 on the precast bridge slab 2 and is cast into the post-cast concrete connecting strip 1.

[0047] The cross-shaped steel 5 includes four profile side support plates 13 and a pair of profile main support plates 6, which are arranged in a cross shape. Each of the outer ends of a profile main support plate 6 is connected to one of the profile side support plates 13. The upper and lower ends of the profile main support plates 6 and the profile side support plates 13 are flush. The four profile side support plates 13 and the pair of profile main support plates 6 together form a hollow columnar structure with a four-corner open cross-section.

[0048] The upper end of the cross-shaped steel 5 is connected to the upper round steel plate 3, and the lower end of the cross-shaped steel 5 is connected to the lower round steel plate 7, so that the connection between the precast pile 8 and the pair of precast bridge plates 2 can undergo plastic deformation under continuous load.

[0049] The upper round steel plate 3, the lower round steel plate 7, the cross-shaped steel 5 and several screws 4 form a combined connector 10. This combined connector 10 can be prefabricated in the factory, thereby improving the assembly efficiency on the construction site.

[0050] Specifically, the profile side support plate 13 is perpendicular to the profile main support plate 6, the upper round steel plate 3 and the lower round steel plate 7 are parallel, and the center of the upper round steel plate 3 and the center of the lower round steel plate 7 are vertically aligned. The profile main support plate 6 is vertically positioned between the upper round steel plate 3 and the lower round steel plate 7.

[0051] The cross-shaped steel 5 is centered between the upper circular steel plate 3 and the lower circular steel plate 7. A pair of the profile main support plates 6 are centered between the four profile side support plates 13.

[0052] Example 2 This embodiment provides a connection structure for a rigid seismic joint of pile-slab roadbed. The main difference from Embodiment 1 is that in this embodiment, the area of ​​the upper circular steel plate 3 is larger than the area of ​​the lower circular steel plate 7. The diameter of the upper circular steel plate 3 is larger than the width of the post-cast concrete connecting strip 1. The post-cast concrete connecting strip 1 is located at the center of the upper circular steel plate 3, so that the upper circular steel plate 3 can support the bottom of a pair of precast bridge slabs 2 respectively.

[0053] Specifically, in this embodiment, the support length of the upper circular steel plate 3 to the post-cast concrete connecting strip 1 on each side is greater than or equal to 150mm.

[0054] Example 3 This embodiment provides a connection structure for a pile-slab rigid seismic joint in a pile-slab roadbed. The main difference from Embodiment 1 is that in this embodiment, the side length of the inscribed quadrilateral of the lower circular steel plate 7 is greater than the side length of the cross-shaped steel 5, so that the cross-shaped steel 5 can be fully welded when welded to the lower circular steel plate 7.

[0055] Example 4 This embodiment provides a connection structure for a rigid seismic-resistant pile-slab joint in a pile-slab roadbed. The main difference from Embodiment 1 is that in this embodiment: the multiple profile side support plates 13 have the same specifications; the pair of profile main support plates 6 have the same specifications, and the length of the profile side support plate 13 is less than the length of the profile main support plate 6; the top of the precast pile 8 is provided with a pile end plate 12 for connecting the lower circular steel plate 7; the diameter of the pile end plate 12 and the diameter of the lower circular steel plate 7 are the same as the diameter of the precast pile 8.

[0056] Example 5 This embodiment provides a connection structure for a rigid seismic-resistant pile-slab joint in a pile-slab roadbed. The main difference from Embodiment 1 is that in this embodiment, the upper circular steel plate 3 has several bolt holes 9, the screw 4 is fixed to the bolt holes 9 by nuts, and the screw 4 is distributed on a virtual circle with the same center as the upper circular steel plate 3.

[0057] Comparative Example Using the pile-slab seismic joint structure disclosed in the utility model with authorization announcement number CN223292884U as a comparative example, this utility model is used to demonstrate that the connection structure of the pile-slab rigid seismic joint in the pile-slab roadbed provided by this utility model has better energy dissipation capacity, improved strength degradation stability and ability to resist repeated loads in the pile-slab roadbed.

[0058] Performance testing To verify the rationality and seismic performance of the structure, a model test was conducted on the connection structure of the pile-slab rigid seismic-resistant joint in the pile-slab roadbed provided in Example 1. The specific parameters of the connection structure of the pile-slab rigid seismic-resistant joint in the pile-slab roadbed in the test are as follows: The upper and lower round steel plates are made of Q235 steel with a thickness of 16 mm. The bolts are 10.9 grade M27 high-strength bolts with a length of 500 mm.

[0059] like Figure 1 As shown, during splicing, first, four screws are passed through the upper round steel plate and pre-tightened with nuts. At the same time, the lower end of the cross-shaped steel is welded to the lower round steel plate, and the upper end of the cross-shaped steel is welded to the upper round steel plate. Then, the lower round steel plate is welded to the end of the pipe pile.

[0060] Then, two precast bridge slabs are overlapped on the upper round steel plate, with an overlap length of 150mm for each precast slab. Finally, C40 grout is poured at the overlap to complete the connection structure splicing of the pile-slab rigid seismic joint in the pile-slab roadbed.

[0061] The pile-slab seismic joint structure used in the comparative model is compared with that in the model.

[0062] After fabrication, a low-cycle reciprocating loading test was conducted with a vertical load of 900 kN.

[0063] In the initial stage of the test, the displacement increased by 2 mm at each level, and each level was subjected to only one complete cycle. When the measured local or overall strain reached the predetermined yield strain value, the displacement amplitude was defined as the specimen's yield displacement. Subsequently, the loading step size was adjusted to half of the defined yield displacement, and three cycles of loading were performed at each displacement level until the horizontal load decreased to below 85% of the peak load or the specimen failed, making it impossible to continue applying control displacement.

[0064] Test results as follows Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10 As shown. Among them, Figure 5 The hysteresis curve is from the connection structure test in Example 1. Figure 8To compare the hysteresis curves of the pile-slab seismic joint structure in the scheme. From... Figure 5 As can be seen, the hysteresis curve is bow-shaped, and the area of ​​the hysteresis curve is greater than that of the curve. Figure 8 The large value indicates that Example 1 has better energy consumption capability.

[0065] Figure 6 The energy dissipation capacity curve of the connection structure test in Example 1 is shown. Figure 10 This is a comparison chart of energy consumption capacity curves. From... Figure 6 and Figure 10 As can be seen from the data, during the loading process of the connection structure provided in Example 1, the equivalent viscous damping coefficient of the specimen remained between 0.23 and 0.40. The overall equivalent viscous damping coefficient was relatively large, indicating strong energy dissipation capacity. Furthermore, the final cumulative energy dissipation was 58.2% higher than that of the comparative example, thus reflecting its good seismic performance.

[0066] Figure 7 The strength degradation curve of the connection structure in Example 1 is shown in the test. Figure 7 As can be seen, the strength degradation curve shows an overall downward trend as the loading displacement increases, but the degradation coefficient is not lower than 0.95. This indicates that the connection structure in Example 1 has strong strength degradation stability and resistance to repeated loading, and the specimen exhibits more stable load-bearing characteristics.

[0067] Figure 9 This is a comparison diagram of the pile-slab seismic joint structure skeleton curves in this utility model and the comparative scheme. Figure 9 As can be seen, the average peak displacement of the connection structure in Example 1 increased by 15.70 mm, or about 22.36%, compared with the average peak displacement in the comparative example. This shows that the connection structure in Example 1 has better toughness and can improve the deformation capacity of the specimen to a certain extent.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. A connection structure for a rigid seismic-resistant pile-slab joint in a pile-slab roadbed, disposed between a pair of precast bridge slabs and precast piles, characterized in that: It includes an upper circular steel plate, a lower circular steel plate, a cross-shaped steel bar, several bolts, and a post-cast concrete connecting strip poured between a pair of the precast bridge slabs; The lower end circular steel plate is fixedly connected to the precast pile, and the upper end circular steel plate is set at the bottom of the post-cast concrete connecting strip and the precast bridge plate to support the post-cast concrete connecting strip and the precast bridge plate from below. The lower end of the screw is fixed to the top of the upper round steel plate, and the upper end of the screw intersects with the inter-plate connecting steel bars on the precast bridge plate and is cast into the post-cast concrete connecting strip. The cross-shaped steel section includes multiple profile side support plates and a pair of profile main support plates. The pair of profile main support plates are arranged in a cross shape. The outer ends of each profile main support plate are connected to a profile side support plate. The upper and lower ends of the profile main support plates and the profile side support plates are flush. The multiple profile side support plates and the pair of profile main support plates together form a square-shaped hollow column structure with four open corners in cross section. The upper end of the cross-shaped steel section is connected to the upper round steel plate, and the lower end of the cross-shaped steel section is connected to the lower round steel plate, so that the connection between the precast pile and the pair of precast bridge plates can undergo plastic deformation under continuous load.

2. The connection structure of the pile-slab rigid seismic joint in the pile-slab roadbed according to claim 1, characterized in that: The profile side support plate is perpendicular to the profile main support plate, the upper round steel plate is parallel to the lower round steel plate, and the center of the upper round steel plate is vertically aligned with the center of the lower round steel plate. The profile main support plate is vertically positioned between the upper round steel plate and the lower round steel plate.

3. The connection structure of the pile-slab rigid seismic joint in the pile-slab roadbed according to claim 2, characterized in that: The cross-shaped steel is centered between the upper and lower round steel plates so that the upper round steel plate can smoothly transfer the load it receives to the lower round steel plate through the cross-shaped steel.

4. The connection structure of the pile-slab rigid seismic joint in the pile-slab roadbed according to claim 1, 2, or 3, characterized in that: A pair of main support plates of the profile are centered and connected between multiple side support plates of the profile, so that the multiple side support plates of the profile form a stable frame structure in the lateral direction through the main support plates of the profile.

5. The connection structure of the pile-slab rigid seismic joint in the pile-slab roadbed according to claim 1, characterized in that: The area of ​​the upper circular steel plate is larger than that of the lower circular steel plate, and the diameter of the upper circular steel plate is larger than the width of the post-cast concrete connecting strip. The post-cast concrete connecting strip is located at the center of the upper circular steel plate, so that the upper circular steel plate can support the bottom of a pair of precast bridge slabs respectively.

6. The connection structure of the pile-slab rigid seismic joint in the pile-slab roadbed according to claim 5, characterized in that: The supporting length of the upper circular steel plate for the post-cast concrete connecting strip on each side is greater than or equal to 150mm.

7. The connection structure of the pile-slab rigid seismic joint in a pile-slab roadbed according to claim 1, 2, 3, 5, or 6, characterized in that: The side length of the inscribed quadrilateral of the lower circular steel plate is greater than the side length of the cross-shaped steel, so that the cross-shaped steel can be fully welded when welded to the lower circular steel plate.

8. The connection structure of the pile-slab rigid seismic joint in the pile-slab roadbed according to claim 1, characterized in that: The multiple profile side support plates have the same specifications, the pair of profile main support plates have the same specifications, and the length of the profile side support plates is less than the length of the profile main support plates, so as to reserve deformation space between the multiple profile side support plates.

9. The connection structure of the pile-slab rigid seismic joint in a pile-slab roadbed according to claim 1, 2, 3, 5, 6, or 8, characterized in that: The upper circular steel plate has several bolt holes, and the screw is fixed in the bolt holes by nuts. The screws are distributed on a virtual circle with the same center as the upper circular steel plate.

10. The connection structure of the pile-slab rigid seismic joint in a pile-slab roadbed according to claim 1, 2, 3, 5, 6, or 8, characterized in that: The top of the precast pile is provided with a pile end plate for connecting the lower circular steel plate. The diameter of the pile end plate and the diameter of the lower circular steel plate are the same as the diameter of the precast pile, so that the pile end plate, the lower circular steel plate and the precast pile can be welded together across the entire cross section.

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