A self-centering precast and assembled bridge pier

Abstract

The present invention belongs to the technical field of bridge engineering, and particularly relates to a self-centering precast and assembled bridge pier. The self-centering precast and assembled bridge pier comprises a foundation cap section, a pier top section, a pier body, an energy dissipation inner core, prestressed steel strands and SMA energy dissipation bars; the pier body comprises a top precast segment, a bottom precast segment and at least one intermediate precast segment which are vertically arranged, the bottom end of the energy dissipation inner core is inserted into the foundation cap section, and the top end passes through the bottom precast segment and is inserted into the intermediate precast segment connected thereto; the prestressed steel strands comprise a plurality of integral prestressed steel strands and a plurality of local prestressed steel strands, the integral prestressed steel strands simultaneously pass through the pier top section, the top precast segment, each intermediate precast segment, the bottom precast segment and the foundation cap section, and the local prestressed steel strands pass through the energy dissipation inner core and the foundation cap section; the SMA energy dissipation bars pass through the bottom precast segment and are anchored in the foundation cap section and the intermediate precast segment. The present invention can simultaneously take into account the self-centering function and the energy dissipation function of the precast and assembled bridge pier.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge engineering, and in particular relates to a self-resetting prefabricated assembled bridge pier. Background Art

[0002] Prefabrication and assembly technology is widely used in bridge construction. Prefabricated components are transported from factories to the construction site for assembly. This maximizes the speed of bridge construction while ensuring component quality, effectively minimizing the impact of on-site construction on the surrounding environment. Prefabricated piers offer advantages such as reduced overhead working time, high construction efficiency, guaranteed quality, a short construction period, minimal environmental pollution, low maintenance and repair costs, and minimal disruption to existing traffic. They have become a crucial structural form required for the rapid and sound development of bridge construction technology and are being increasingly used in bridge construction.

[0003] Compared with traditional cast-in-place bridge piers, the segmental connection components of prefabricated assembled piers are usually subject to greater local stresses under earthquakes, making them more susceptible to damage and deterioration. Prefabricated assembled piers can swing left and right due to the opening and closing of dry joints under earthquakes, and are reset by the tension of prestressed strands. Therefore, they have good post-earthquake self-reset capabilities and are also called swing-self-reset piers. However, due to the weak overall constraints of these piers and the damage under earthquakes mainly concentrated in the protective layer of concrete in the joints at the rigid rotation point of the column base, this significantly reduces damage to other parts of the pier body, but also reduces the energy dissipation capacity of the pier. How to effectively reduce the damage of segmented assembled piers under earthquakes and improve the overall ductility and hysteretic energy dissipation capacity of the structure are urgent issues that need to be addressed. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a self-resetting prefabricated assembled bridge pier to solve the technical problem that the self-resetting function and energy dissipation function of the existing prefabricated assembled bridge pier cannot be taken into account at the same time.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A self-resetting prefabricated assembled bridge pier, comprising:

[0007] foundation bearing section;

[0008] pier top section;

[0009] The pier body comprises a top precast segment and a bottom precast segment arranged vertically, and at least one intermediate precast segment provided between the top precast segment and the bottom precast segment, wherein the top precast segment is connected to the pier top segment, and the bottom precast segment is connected to the foundation cap segment;

[0010] The energy-consuming inner core is arranged inside the bottom precast segment. The bottom end of the energy-consuming inner core is inserted into the foundation pile cap segment, and the top end of the energy-consuming inner core passes through the bottom precast segment and is inserted into the intermediate precast segment connected to the bottom precast segment.

[0011] The prestressed steel strands include multiple integral prestressed steel strands and multiple local prestressed steel strands. The integral prestressed steel strands pass through the pier top segment, the top precast segment, each intermediate precast segment, the bottom precast segment, and the foundation pile cap segment simultaneously. The top end of the integral prestressed steel strands is anchored at the top of the pier top segment, and the bottom end of the integral prestressed steel strands is anchored at the bottom of the foundation pile cap segment. The local prestressed steel strands pass through the energy-consuming inner core and the foundation pile cap segment simultaneously. The top end of the local prestressed steel strands is anchored at the top of the energy-consuming inner core, and the bottom end of the local prestressed steel strands is anchored at the bottom of the foundation pile cap segment.

[0012] There are multiple SMA energy-consuming bars arranged in parallel with each prestressed steel strand. The SMA energy-consuming bars pass through the bottom precast segment. The top end of the SMA energy-consuming bars is anchored in the intermediate precast segment connected to the bottom precast segment, and the bottom end of the SMA energy-consuming bars is anchored in the foundation pile cap segment.

[0013] Furthermore, the pier is of a hollow structure. Hollow holes that penetrate through coaxially up and down are provided on the top precast segment, the intermediate precast segments, and the bottom precast segment. Integral steel strand ducts for the integral prestressed steel strands to pass through are provided at positions on both sides of the hollow holes on the top precast segment, the intermediate precast segments, and the bottom precast segment in a one-to-one correspondence up and down. The energy-consuming inner core is arranged inside the hollow hole. Local steel strand ducts for the local prestressed steel strands to pass through are provided on the energy-consuming inner core and the foundation pile cap segment in a one-to-one correspondence up and down. SMA bar ducts that communicate with each other up and down are provided on the left and right sides of the hollow hole on the bottom precast segment, the foundation pile cap segment, and the intermediate precast segment connected to the bottom precast segment.

[0014] Furthermore, the integral steel strand ducts on the same side of the hollow hole are arranged side by side at equal intervals.

[0015] Furthermore, the SMA bar ducts are arranged between two adjacent integral steel strand ducts.

[0016] Furthermore, the energy-consuming inner core is of a variable cross-section structure, including a large-diameter segment adapted to the hollow hole and a small-diameter segment coaxial with the large-diameter segment. The small-diameter segment is inserted into the foundation pile cap segment, the large-diameter segment is located between the bottom precast segment and the intermediate precast segment connected to the bottom precast segment, and the local steel strand ducts are provided on the small-diameter segment and at the position on the large-diameter segment corresponding to the small-diameter segment.

[0017] Furthermore, L-shaped steel bars are embedded at the positions corresponding to the SMA energy-dissipating bars in the foundation pile cap section. A sleeve is connected to the vertical section of the L-shaped steel bar, and the bottom of the SMA energy-dissipating bar is connected to the L-shaped steel bar through the sleeve.

[0018] Furthermore, the energy-dissipating inner core is cast from a new type of concrete material, ECC (engineered cementitious composite) or UHPC (ultra-high performance concrete).

[0019] The beneficial effects of the self-centering precast segmental bridge pier of the present invention are as follows:

[0020] 1. The overall fit between the pier top segment, the foundation pile cap segment, and each precast segment of the pier body is high, and they are effectively connected into a whole, improving the lateral stiffness and effectively reducing the lateral displacement between each segment under the horizontal seismic action.

[0021] 2. A precast segmental bridge pier with a hybrid system is adopted. The energy-dissipating inner core is inserted into the foundation pile cap segment, which makes the plastic hinge move upward, effectively alleviating the concrete damage and improving the overall seismic performance of the structure. Even under the seismic action, the energy-dissipating inner core is damaged, but since the energy-dissipating inner core is assembled with the foundation pile cap segment through prestressed steel strands, it can be replaced in time to achieve the effect of rapid repair. The energy-dissipating inner core can use new type of concrete materials such as ECC and UHPC to enhance the energy-dissipating ability of the energy-dissipating inner core and overall improve the seismic performance of the bridge pier. Compared with ordinary concrete, ECC has stronger deformation performance, lighter weight, and better seismic performance. Using ECC in the energy-dissipating inner core can fully deform to increase the energy-dissipating ability; UHPC has very high compressive strength, and at the same time, its toughness and durability are extremely excellent, and it can still remain intact under multiple cyclic loads. When an earthquake comes, it can resist repeated loads and is not easy to crack, thus fully dissipating energy. Therefore, using these two materials can better reflect the energy-dissipating effect of the energy-dissipating inner core.

[0022] 3. The part of the SMA energy-dissipating bar extending into the foundation pile cap segment is connected to the embedded L-shaped steel bar in the foundation pile cap segment through a sleeve. The SMA energy-dissipating bar undergoes a certain number of tensile-compressive trainings along the long side direction, generating martensite-austenite transformation superelasticity at room temperature. When the structure makes the bottom precast segment swing under the seismic action, the SMA energy-dissipating bar and the tensile stress of the overall prestressed steel strands act together to form a better self-centering driving force. Under the seismic action of the multi-hazard earthquake intensity, the SMA energy-dissipating bar and the local prestressed steel strands in the energy-dissipating inner core can provide additional lateral stiffness and participate in energy dissipation; under the seismic action of the fortification intensity or rare earthquake intensity, by using the combined action of the SMA energy-dissipating bar and the tensile stress of the prestressed steel strands, the residual displacement of the structure can be reduced, and self-repair after the earthquake can be achieved.

[0023] 4. The precast and assembled bridge pier adopts a rocking structure form. SMA energy-dissipating bars and integral prestressed steel strands are arranged in the plastic hinge area, and an energy-dissipating inner core is arranged at the connection between the bottom precast segment and the foundation cap segment. They work together to dissipate energy. When affected by an earthquake with the fortification intensity or the rare earthquake intensity, the seismic energy can be dissipated through the rocking and energy-dissipating system, enabling the structure to still not lose its service function under the influence of an earthquake with the fortification intensity or the rare earthquake intensity.

[0024] 5. The self-centering precast and assembled bridge pier makes full use of the superelasticity and shape memory property of the shape memory alloy bars, improves the energy-dissipating capacity of the precast and assembled bridge pier and realizes the recoverability of functions, reduces the residual displacement, and achieves rapid resetting. The arrangement of the energy-dissipating inner core and the local prestressed steel strands therein fully connects the foundation cap segment and the upper pier shaft segment, making the integrity between the foundation cap segment and the upper pier shaft stronger, improving the lateral stiffness and energy-dissipating capacity of the precast and assembled bridge pier, relieving the stress concentration here, and effectively reducing the damage at the foundation cap segment and the bottom precast segment of the pier shaft under the earthquake action.

[0025] 6. The energy-dissipating inner core, the pier shaft, and the pier top segment can all be assembled by the method of factory prefabrication and on-site assembly. The prestressed steel strands are tensioned and fixed through anchor devices, and the SMA energy-dissipating bars are fixed through sleeves and anchor devices. The overall structure is simple, the construction is convenient and fast, and the applicable range is wide. Description of the Drawings

[0026] Figure 1 is the overall structural schematic diagram of the self-centering precast and assembled bridge pier of the present invention;

[0027] Figure 2 is Figure 1 the top view of

[0028] Figure 3 is Figure 2 the A-A sectional view of

[0029] Figure 4 is Figure 2 the B-B sectional view of

[0030] Figure 5 is the structural exploded schematic diagram of the self-centering precast and assembled bridge pier of the present invention;

[0031] Figure 6 is the sectional schematic diagram of the bottom precast segment in the self-centering precast and assembled bridge pier of the present invention;

[0032] Figure 7 is the top sectional schematic diagram of the middle precast segment in the self-centering precast and assembled bridge pier of the present invention;

[0033] Figure 8 is the structural schematic diagram of the energy-dissipating inner core in the self-centering precast and assembled bridge pier of the present invention.

[0034] Description of reference numerals: 1 - pier top section, 2 - foundation cap section, 3 - pier shaft, 4 - top precast segment, 5 - bottom precast segment, 6 - intermediate precast segment, 7 - energy dissipation inner core, 8 - large-diameter section, 9 - small-diameter section, 10 - SMA energy dissipation bars, 11 - overall prestressed steel strands, 12 - local prestressed steel strands, 13 - anchor, 14 - overall steel strand duct, 15 - SMA bar duct, 16 - hollow hole, 17 - L-shaped steel bars, 18 - sleeve. Specific embodiments

[0035] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0036] Specific embodiment of the self-centering precast assembled pier of the present invention:

[0037] As Figure 1 , Figure 2 and Figure 5 shown, the self-centering precast assembled pier includes a foundation cap section 2, a pier top section 1, a pier shaft 3, an energy dissipation inner core 7, prestressed steel strands and SMA energy dissipation bars 10.

[0038] Specifically, as Figure 1 and Figure 5 shown, the foundation cap section 2 is cast in place on site, and the pier top section 1, the pier shaft 3 and the energy dissipation inner core 7 are all precast in the factory. Among them, the pier shaft 3 is a hollow structure, which effectively reduces the amount of concrete used while ensuring the support strength. The pier shaft 3 includes a top precast segment 4, a bottom precast segment 5 arranged vertically, and an intermediate precast segment 6 provided between the top precast segment 4 and the bottom precast segment 5. The shapes and sizes of the top precast segment 4, the bottom precast segment 5 and the intermediate precast segment 6 are the same, and the cross sections are all box-shaped. The top precast segment 4 is connected to the pier top section 1 and the intermediate precast segment 6, and the bottom precast segment 5 is connected to the foundation cap section 2 and the intermediate precast segment 6 through the insertion connection of shear keys and steel grooves. This connection method is a prior art, so it is not shown in the figure. As Figure 3 shown, the top precast segment 4, the bottom precast segment 5 and the intermediate precast segment 6 are all provided with coaxial and vertically penetrating hollow holes 16. To ensure the connection reliability, a gelling material, such as epoxy resin, is applied between adjacent precast segments for bonding, increasing the contact area between the cross sections of adjacent precast segments and making the connection integrity between each precast segment better. The insertion connection method can ensure the assembly accuracy between each segment and improve the assembly efficiency between each segment.

[0039] The energy dissipation inner core 7 is formed by casting with a new type of concrete material ECC. Of course, in other embodiments, the energy dissipation inner core 7 can also be formed by casting with UHPC. As Figure 8As shown, the energy-dissipating inner core 7 has a variable cross-section structure, including a large-diameter section 8 adapted to the hollow hole 16 and a small-diameter section 9 coaxial with the large-diameter section 8. If the energy-dissipating inner core 7 is designed with a constant cross-section according to the size of the upper large-diameter section, the hole size in the upper part of the foundation pile cap is large, and the stress area under load is small, which is prone to failure; if it is designed with a constant cross-section according to the size of the lower small-diameter section of the energy-dissipating inner core 7, the inner diameter size of the hollow hole is small, and it is necessary to add materials to the inner cross-section with less force, resulting in additional costs. Therefore, the variable cross-section form takes into account both safety and economy. As Figure 3 and Figure 4 shown, the energy-dissipating inner core 7 is arranged in the bottom precast segment 5. In this embodiment, part of the large-diameter section 8 of the energy-dissipating inner core 7 is located in the hollow hole of the bottom precast segment 5, and part is inserted into the hollow hole of the middle precast segment 6; part of the small-diameter section 9 of the energy-dissipating inner core 7 is located in the hollow hole of the bottom precast segment 5, and there is a gap between this part and the inner wall of the bottom precast segment 5, and part is inserted into the foundation pile cap segment 2. In actual construction, the energy-dissipating inner core 7 only needs to be assembled with the bottom precast segment 5 and the middle precast segment 6, without filling the gap. The gap is allowed to exist, giving a certain degree of mobility, so that appropriate rocking energy dissipation occurs at the bottom precast segment 5.

[0040] As Figure 5 shown, the prestressed steel strands include multiple integral prestressed steel strands 11 and multiple local prestressed steel strands 12. As Figure 6 and Figure 7 shown, three integral steel strand ducts 14 for the integral prestressed steel strands 11 to pass through, which are vertically corresponding and penetrating, are provided at the positions on the left and right sides of the hollow hole 16 on the top precast segment 4, the middle precast segment 6 and the bottom precast segment 5. Six corresponding integral steel strand ducts 14 are provided on the pier top segment 1 and the foundation pile cap segment 2. In this embodiment, the integral steel strand ducts 14 on the same side of the hollow hole 16 are arranged side by side at equal intervals. Each integral prestressed steel strand 14 passes through the pier top segment 1, the top precast segment 4, each middle precast segment 6, the bottom precast segment 5 and the foundation pile cap segment 2 at the same time; the top end of the integral prestressed steel strand 11 is anchored at the top of the pier top segment 1 through the anchor 13, and the bottom end of the integral prestressed steel strand 11 is anchored at the bottom of the foundation pile cap segment 2 through the anchor 13.

[0041] As Figure 3 、 Figure 4 and Figure 8As shown, at the central positions of the small-diameter section 9 and the large-diameter section 8 of the energy-dissipating inner core 7, and on the foundation pile cap section 2, there are local strand ducts (not shown in the figure) through which the local prestressed steel strands 12 pass through in a one-to-one correspondence from top to bottom. Each local prestressed steel strand 12 passes through the energy-dissipating inner core 7 and the foundation pile cap section 2 through the local strand duct. The top end of the local prestressed steel strand 12 is anchored at the top of the large-diameter section 8 of the energy-dissipating inner core through the anchor 13, and the bottom end of the local prestressed steel strand 12 is anchored at the bottom of the foundation pile cap section 2 through the anchor 13. In this embodiment, the structures of each anchor 13 are the same and are all prior arts, so the structure will not be described in detail again.

[0042] As Figure 5 and Figure 6 shown, in this embodiment, there are four SMA energy-dissipating bars 10, which are parallel to each prestressed steel strand. The SMA energy-dissipating bar is made of shape memory alloy material, and copper-manganese-aluminum alloy can be used. As shown in the figure, on the bottom precast segment 5, the foundation pile cap section 2, and the middle precast segment 6, there are two SMA bar ducts 15 that are in one-to-one correspondence and communicate with each other from top to bottom on the left and right sides of the hollow hole 16. The SMA bar ducts 15 are arranged between two adjacent integral strand ducts 14 and are in the same row as the integral strand ducts 14, showing an alternating distribution. The distance between any adjacent SMA bar duct 15 and the integral strand duct 14 is equal. The SMA bar duct 15 on the bottom precast segment 5 is a through hole, and the SMA bar ducts 15 on the foundation pile cap section 2 and the middle precast segment 6 are blind holes. The top end of the SMA energy-dissipating bar 10 is anchored in the middle precast segment 6 through the anchor 13, and the bottom end of the SMA energy-dissipating bar 10 passes through the bottom precast segment 5 and is anchored in the foundation pile cap section 2.

[0043] As Figure 5 shown, at the position corresponding to the SMA energy-dissipating bar 10 in the foundation pile cap section 2, an L-shaped steel bar 17 is embedded. A sleeve 18 is connected to the vertical section of the L-shaped steel bar 17, and the bottom of the SMA energy-dissipating bar 10 is connected to the sleeve 18. When constructing the SMA energy-dissipating bar 10, first pour the foundation pile cap section 2, arrange the L-shaped steel bar 17 in advance in the foundation pile cap section 2, connect the upper part of the L-shaped steel bar 17 to the SMA energy-dissipating bar 10 through the sleeve 18, then install the template for pouring, remove the formwork after the strength reaches the requirement, then assemble the bottom precast segment 5 to install the SMA energy-dissipating bar 10, and insert the anchor 13 at the top of the bottom precast segment 5 and clamp it tightly, fix it as required, and cast micro-expansion self-leveling cement slurry between the SMA energy-dissipating bar 10 and the SMA bar duct 15.

[0044] In this embodiment, when tensioning the prestressed steel strands, two schemes can be adopted. One is one-side tensioning, and the other is two-end symmetric tensioning. The objects of tensioning are the integral prestressed steel strands and the local prestressed steel strands.

[0045] Among them, the one-side tensioning scheme is divided into two steps: the first step is to tension the local prestressed steel strands 12 in the energy-dissipating inner core 7, and the second step is to tension the overall prestressed steel strands 11 arranged longitudinally. Specifically, in the first step: first insert the energy-dissipating inner core 7 into the rectangular hole at the top of the foundation pile cap section 2, reserve a central hole in the foundation pile cap section 2 to thread the local prestressed steel strands 12 in the energy-dissipating inner core 7, insert the local prestressed steel strands 12 in the rectangular hole reserved at the bottom of the foundation pile cap section 2 for tensioning on one side into the anchor 13 and clamp them, fix them according to the design requirements, arrange tensioning machinery at the top of the energy-dissipating inner core 7, and tension on one side. In the second step: thread the overall prestressed steel strands 11 arranged longitudinally in the overall steel strand duct 14 of the foundation pile cap section 2, insert the overall prestressed steel strands 11 in the through hole reserved for tensioning on one side of the foundation pile cap section 2 into the anchor 13 and clamp them, fix them as required, place them vertically, and successively place the middle precast segment 6, the top precast segment 4 and the pier top segment 1. After the pier top segment 1 is placed, insert the overall prestressed steel strands 11 in the hole reserved for tensioning on one side of the pier top segment 1 into the anchor 13 and clamp them, arrange tensioning machinery at the pier top segment 1, and tension on one side.

[0046] The two-end symmetric tensioning scheme is divided into two steps: the first step is to tension the local prestressed steel strands 12 in the energy-dissipating inner core 7 and the foundation pile cap section 2, and the second step is to tension the overall prestressed steel strands 11 arranged longitudinally. The first step: first insert the energy-dissipating inner core 7 into the rectangular hole at the top of the foundation pile cap section 2, place it flat on the cushion layer, reserve a central hole in the foundation pile cap section 2 to thread the local prestressed steel strands 12 in the energy-dissipating inner core 7, and use anchors to fix them at the bottom of the foundation pile cap section 2 and the top of the energy-dissipating inner core 7, and tension symmetrically at both ends. The second step: place the tensioned energy-dissipating inner core 7, the bottom precast segment 5, the foundation pile cap section 2 and other components flat on the cushion layer, thread the overall prestressed steel strands 11 arranged longitudinally, use anchors to fix them at the through hole reserved at the bottom of the foundation pile cap section 2 and the top of the pier top segment 1, and tension symmetrically at both ends, and then use a hoisting device to lift the pier structure as a whole and place it properly.

[0047] The force analysis of the self-centering precast assembled pier of the present invention shows that:

[0048] 1. For the analysis of the self-centering precast assembled pier to resist the horizontal cross-bridge seismic action, the longitudinal seismic resistance can be arranged according to the cross-bridge structural form. When the structure is subjected to the cross-bridge seismic action, the acting force is transmitted from bottom to top along the foundation, and can be simplified as applying a reciprocating horizontal force at the top surface of the pier column of the pier.

[0049] 2. Adopting the full-segment precast assembly technology, compared with the traditional casting method, the construction efficiency is improved. SMA energy-dissipating bars are arranged on both sides of the pier column at the bottom precast segment and the overall prestressed steel strands are arranged longitudinally from top to bottom, and the overall energy-dissipating capacity of the pier is greatly improved.

[0050] 3. When the force transmitted to the pier structure is small under minor earthquakes, no opening cracks appear in the plastic hinge zone segment. The SMA energy dissipation bars on one side of the pier column are in tension, and those on the other side are in compression. The concrete in the plastic hinge zone bears shear stress, and the overall structure is in an elastic state.

[0051] 4. When the earthquake force continues to increase, opening cracks and stress concentration areas appear between the bottom precast segment in the plastic hinge zone and the foundation cap segment. Energy dissipation inner cores are added between the bottom precast segment, the middle precast segment and the foundation cap segment. The energy dissipation inner cores dissipate energy through compression deformation, effectively alleviating the crushing failure of the concrete in the plastic hinge zone. Moreover, the energy dissipation inner cores are assembled with local prestressed steel strands, which not only enhances the energy dissipation capacity of the energy dissipation inner cores but also gives the energy dissipation inner cores a self - resetting effect, reducing the damage to the inner cores.

[0052] 5. Under moderate and major earthquakes, opening cracks appear between the bottom precast segment in the plastic hinge zone and the foundation cap segment, forming a rocking structure. The energy dissipation inner cores are inserted into the foundation cap and fit with the internal cross - sections of the bottom precast segment and the middle precast segment, effectively controlling the width of the opening cracks. The vertical SMA energy dissipation bars in the bottom precast segment and the middle precast segment, and the compression deformation energy dissipation and the combined action of the overall prestressed steel strands in the two parts provide better energy dissipation capacity for the structure and reduce the seismic response of the structure.

[0053] 6. Under repeated earthquakes, the earthquake force is transmitted to the pier structure, causing rocking between pier segments. When the external force decreases or dissipates, a better restoring force is provided under the combined action of the tensile forces of the overall prestressed steel strands arranged throughout the length, the local prestressed steel strands in the energy dissipation inner cores, and the tensile forces of the SMA energy dissipation bars on both sides, restoring to the equilibrium state. Moreover, the SMA energy dissipation bars will utilize the shape memory effect of the material to achieve self - resetting after the earthquake, reducing the residual deformation in the plastic hinge zone.

[0054] The self - resetting precast assembled pier of the present invention can simultaneously take into account the self - resetting function and the energy dissipation function, effectively improving the seismic performance of the bridge.

[0055] In other embodiments, the appropriate number of middle precast segments can be selected according to the height of the pier body.

[0056] The embodiments of the present invention described above do not constitute a limitation on the protection scope of the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A self-resetting prefabricated assembled bridge pier, characterized in that: include: foundation bearing section; pier top section; The pier body comprises a top precast segment and a bottom precast segment arranged vertically, and at least one intermediate precast segment provided between the top precast segment and the bottom precast segment, wherein the top precast segment is connected to the pier top segment, and the bottom precast segment is connected to the foundation cap segment; The energy-absorbing inner core is arranged in the bottom prefabricated segment, the bottom end of the energy-absorbing inner core is inserted into the foundation cap segment, and the top end of the energy-absorbing inner core passes through the bottom prefabricated segment and is inserted into the middle prefabricated segment connected to the bottom prefabricated segment; The prestressed steel strands include a plurality of integral prestressed steel strands and a plurality of local prestressed steel strands. The integral prestressed steel strands simultaneously pass through the pier top section, the top precast segments, the intermediate precast segments, the bottom precast segments, and the foundation cap segment. The top ends of the integral prestressed steel strands are anchored at the top of the pier top section, and the bottom ends of the integral prestressed steel strands are anchored at the bottom of the foundation cap segment. The local prestressed steel strands simultaneously pass through the energy-absorbing inner core and the foundation cap segment. The top ends of the local prestressed steel strands are anchored at the top of the energy-absorbing inner core, and the bottom ends of the local prestressed steel strands are anchored at the bottom of the foundation cap segment. Multiple SMA energy-absorbing bars are provided and are parallel to each prestressed steel strand. The SMA energy-absorbing bars pass through the bottom prefabricated segment. The top end of the SMA energy-absorbing bars is anchored in the middle prefabricated segment connected to the bottom prefabricated segment, and the bottom end of the SMA energy-absorbing bars is anchored in the foundation cap segment. The pier body is a hollow structure, and the top precast segment, the middle precast segment and the bottom precast segment are provided with coaxial hollow holes that penetrate each other vertically. The top precast segment, the middle precast segment and the bottom precast segment are provided with integral steel strand holes that correspond to each other on both sides of the hollow hole, and are used for the integral prestressed steel strand to pass through. The energy-absorbing inner core is arranged in the hollow hole, and the energy-absorbing inner core and the foundation pedestal segment are provided with local steel strand holes that correspond to each other on the top and bottom, and are used for the local prestressed steel strand to pass through. The bottom precast segment, the foundation pedestal segment and the middle precast segment connected to the bottom precast segment are provided with SMA reinforcement holes that correspond to each other on both sides of the hollow hole. The energy-absorbing inner core is a variable cross-section structure, including a large diameter section adapted to the hollow hole and a small diameter section coaxial with the large diameter section. The small diameter section is plugged into the foundation pedestal section. The large diameter section is located between the bottom prefabricated section and the middle prefabricated section connected to the bottom prefabricated section. The local steel strand duct is provided on the small diameter section and the position on the large diameter section corresponding to the small diameter section.

2. The self-resetting prefabricated assembled bridge pier according to claim 1 is characterized in that: The integral steel strand ducts located on the same side of the hollow hole are arranged side by side at equal intervals.

3. The self-resetting prefabricated assembled bridge pier according to claim 2 is characterized in that: The SMA reinforcement channel is arranged between two adjacent integral steel strand channels.

4. The self-resetting prefabricated assembled bridge pier according to any one of claims 1 to 3, characterized in that: An L-shaped steel bar is pre-embedded in the foundation pedestal section at a position corresponding to the SMA energy-absorbing bar. A sleeve is connected to the vertical section of the L-shaped steel bar. The bottom of the SMA energy-absorbing bar is connected to the L-shaped steel bar through the sleeve.

5. The self-resetting prefabricated assembled bridge pier according to any one of claims 1 to 3, characterized in that: The energy-dissipating inner core is cast from ECC or UHPC.

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