Anti-seismic tough structural system of subway station
By using dry joint design at the connection between the central column and the top longitudinal beam of the subway station and using non-bonded prestressed steel strands, the problem of insufficient shear resistance and horizontal deformation ability of the central column under the action of earthquakes is solved, and the efficient seismic resistance and self-restoration of the structure is achieved.
Patent Information
- Application Number
- CN202510160105.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-13
- Publication Date
- 2025-04-11
AI Technical Summary
The shear resistance and horizontal deformation ability of the subway station central column under the action of earthquakes, resulting in the central column being damaged first and losing its function of use, which in turn causes further damage or collapse of the station structure.
By optimizing the connection between the middle column and the top longitudinal beam, the dry joint design is adopted and the connection is made using non-bonded prestressed steel strands. The rear-tension prestressing tightens the top longitudinal beam and the center column, improving the seismic resistance and self-recovery ability of the structure.
It significantly improves the seismic performance and self-resilience of the subway station under the action of earthquakes, weakens the damage of the central pillar during the action of earthquakes, ensures that the central pillar can still play a vertical load-bearing role normally after the earthquake, and avoids the overall failure of the station.
Smart Images
Figure CN119801052A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of underground structural engineering such as rail transit engineering and underground space development, and in particular relates to an earthquake-resistant and resilient structural system for a subway station. Background Art
[0002] As an important part of urban rail transit, subway stations are usually buried deep underground. Their structural safety is directly related to the safety of passengers' lives and property and the normal operation of urban transportation. However, earthquake disasters are extremely destructive to underground structures. Once an earthquake occurs, the disaster prevention, rescue and post-disaster repair of subway stations will face great difficulties, which may cause huge economic losses and casualties. Therefore, improving the seismic resilience of subway stations has become an important guarantee for sustainable development. At present, the middle columns and top plates of subway stations usually adopt cast-in-place rigid connection. This structural design shows obvious defects under earthquake action. Studies have shown that earthquake damage to subway stations is mainly concentrated in the middle columns of the structure. Due to its insufficient shear resistance and deformation capacity, the middle columns are the first to be damaged in an earthquake. The collapse of the middle column of the Daikai subway station in Japan is a typical example, which fully exposes the shortcomings of the existing subway stations in seismic design.
[0003] In the prior art, the middle column and the top plate of the subway station are rigidly connected. Although this design can provide sufficient vertical bearing capacity under normal use conditions, the horizontal deformation capacity of the middle column is insufficient under the action of an earthquake, and it is difficult to adapt to the deformation of the surrounding rock and soil. When an earthquake occurs, the middle column is easily damaged first and loses its function due to the incoordination of its horizontal deformation capacity, which in turn causes further damage to the entire station structure or even collapse. The defects of this structural design not only reduce the safety of the subway station during an earthquake, but also increase the difficulty and cost of post-disaster repair. Therefore, how to improve the overall interlayer deformation capacity of the subway station structure, especially the horizontal deformation capacity of the middle column, has become a key issue in the current seismic design of subway stations. Summary of the invention
[0004] In view of the shortcomings of the prior art, the present invention provides a seismic toughness structural system for a subway station. By optimizing the connection method between the middle column and the top longitudinal beam, the seismic performance and self-recovery ability of the subway station under earthquake action are significantly improved, and the problems of insufficient shear resistance and horizontal deformation capacity of the middle column in the prior art are effectively solved.
[0005] To achieve the above object, the technical solution of the present invention is as follows:
[0006] A seismic toughness structural system for a subway station comprises a top plate, a middle plate, a bottom plate and side walls, which constitute a basic structural frame of the subway station; a middle column is arranged between the top plate and the bottom plate, a top longitudinal beam is arranged below the top plate, a middle longitudinal beam is arranged below the middle plate, and a bottom longitudinal beam is arranged above the bottom plate; the column bottom of the middle column is rigidly connected to the bottom longitudinal beam, and the longitudinal reinforcement between the column top of the middle column and the top longitudinal beam is disconnected to form a dry joint; two bundles of post-tensioned unbonded prestressed steel strands pass through the dry joint, the top of the unbonded prestressed steel strands are anchored to the side of the top longitudinal beam, and the bottom of the unbonded prestressed steel strands are anchored to the side of the bottom longitudinal beam; the unbonded prestressed steel strands tighten the top longitudinal beam and the middle column through post-tensioning prestressing, so that the structural system can play a vertical bearing role under normal use conditions.
[0007] Preferably, when an earthquake occurs, when the horizontal shear force borne by the middle column reaches the friction force required for sliding at the dry joint, the top longitudinal beam and the middle column begin to shift relative to each other until the structural deformation reaches a maximum value. At this time, the unbonded prestressed steel strands provide a restoring force to prevent the shift between the two from being too large and provide a certain recovery trend to avoid affecting the vertical bearing capacity of the middle column.
[0008] Preferably, two bundles of the unbonded prestressed steel strands are disposed inside the center column and are arranged symmetrically.
[0009] Preferably, the bottom of the top longitudinal beam and the outer surface of the top of the middle column are both provided with external protective steel plates to prevent local pressure damage of concrete during earthquakes.
[0010] Preferably, the outer protective steel plate is fixed to the top longitudinal beam and the center column by bolts.
[0011] Preferably, the sides of the top longitudinal beam and the bottom longitudinal beam are provided with structural reserved grooves for re-tensioning or replacing the unbonded prestressed steel strands after an earthquake.
[0012] Preferably, the unbonded prestressed steel strand is protected by a corrugated tube to prevent the steel strand from being damaged during construction and use.
[0013] Preferably, the unbonded prestressed steel strands are arranged in a curve.
[0014] Preferably, the bottom and top of the unbonded prestressed steel strand are anchored by a tensioning end and a fixed end respectively.
[0015] Preferably, the tensioning end and the fixing end are respectively located inside the structure reserved groove.
[0016] Compared with the prior art, the advantages of the present invention are:
[0017] The present invention disconnects the longitudinal reinforcement between the top of the middle column and the top longitudinal beam, and connects them through a dry joint and two bundles of unbonded prestressed steel strands running through them. The top of the unbonded prestressed steel strand is anchored to the side of the top longitudinal beam, and the bottom is anchored to the side of the bottom longitudinal beam, so that it can be easily replaced or re-tensioned after an earthquake, thereby improving the maintainability and service life of the structure. In terms of structural design, the system cuts off the path for the horizontal seismic load to be transmitted to the middle column, reduces the stress level of the middle column under the action of an earthquake, thereby effectively reducing or eliminating the damage to the middle column during an earthquake, and improving the safety and seismic resistance of the station structure. At the same time, by utilizing the restoring force provided by the unbonded prestressed steel strand, the relative displacement between the top of the middle column and the top longitudinal beam during an earthquake can be corrected or even restored to a certain extent after the earthquake, ensuring that the middle column can still play a normal vertical bearing role after the earthquake, and avoiding the overall failure of the station due to excessive permanent deformation. The invention has a simple structure, convenient construction, strong economy, and a certain self-recovery ability. It can effectively improve the seismic toughness of the subway station structure, conforms to the design concept of underground structure toughness, and provides a new idea for the seismic design of rail transit and other underground projects. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a cross-sectional view of a subway station of the present invention.
[0019] Figure numerals: 1-top plate; 2-middle plate; 3-bottom plate; 4-side wall; 5-middle column; 6-top longitudinal beam; 7-middle longitudinal beam; 8-bottom longitudinal beam; 9-corrugated pipe; 10-unbonded prestressed steel strand; 11-external protective steel plate; 12-structural reserved groove; 13-tensioning end; 14-fixed end. DETAILED DESCRIPTION
[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the present invention.
[0021] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.
[0022] like Figure 1As shown, this embodiment discloses a seismic toughness structural system of a subway station, including a top plate 1, a middle plate 2, a bottom plate 3 and a side wall 4, which constitute the basic structural frame of the subway station. The top plate 1 is arranged at the top of the station and connected to the side wall 4, playing the role of closing the station structure. The middle plate 2 is located in the middle of the station, bearing part of the vertical load and enhancing the overall rigidity. The bottom plate 3 constitutes the foundation part of the station and is connected to the side wall 4 to form an overall support, so that the station can withstand the foundation reaction force and other vertical and horizontal forces.
[0023] A middle column 5 is arranged between the top plate 1 and the bottom plate 3. The middle column 5 is used to share the vertical load of the station structure and provide a certain lateral stability when an earthquake occurs. A top longitudinal beam 6 is arranged below the top plate 1. The top longitudinal beam 6 is arranged in parallel with the top plate 1 to provide additional rigidity and support for the station and is connected to the top of the middle column 5. A middle longitudinal beam 7 is arranged below the middle plate 2. The middle longitudinal beam 7 enhances the overall stability of the station structure and helps to control lateral deformation during an earthquake. A bottom longitudinal beam 8 is arranged above the bottom plate 3. The bottom longitudinal beam 8 is used to enhance the bearing capacity of the bottom plate 3. The bottom of the middle column 5 is rigidly connected to the bottom longitudinal beam 8. This connection method ensures that the middle column 5 can reliably transfer the load to the bottom longitudinal beam 8 during an earthquake, and finally disperse it to the bottom plate 3, ensuring the balanced force of the overall structure.
[0024] The longitudinal reinforcement between the top of the middle column 5 and the top longitudinal beam 6 is disconnected to form a dry joint. In the traditional subway station structure, the middle column 5 and the top longitudinal beam 6 are usually connected by cast-in-place rigid connection. This connection method is easy to cause the middle column 5 to be damaged due to shear overload under the action of an earthquake, and even cause serious damage to the entire station structure. This embodiment adopts a dry joint design, that is, no continuous longitudinal reinforcement is set between the top of the middle column 5 and the top longitudinal beam 6, but a connection that allows a certain amount of displacement is formed through a special splicing method, so as to reduce the shear force borne by the middle column 5 during an earthquake and improve the seismic resistance of the station structure.
[0025] Two bundles of post-tensioned unbonded prestressed steel strands 10 run through the dry joints. The top of the unbonded prestressed steel strands 10 are anchored to the side of the top longitudinal beam 6, and the bottom is anchored to the side of the bottom longitudinal beam 8. The unbonded prestressed steel strands 10 are prestressed steel bars with protective materials wrapped on the surface of the steel strands. They can deform independently when subjected to force, and will not bond with concrete, so that they can effectively provide restoring force and reduce residual deformation of the structure when an earthquake occurs. The top of the unbonded prestressed steel strands 10 is anchored to the side of the top longitudinal beam 6 to ensure that the steel strands 10 can be tightly connected to the top longitudinal beam 6 during an earthquake, and provide restoring force after the middle column 5 and the top longitudinal beam 6 are displaced; the bottom is anchored to the side of the bottom longitudinal beam 8 to ensure that it can stably transmit force when subjected to earthquake loads, and is convenient for post-earthquake maintenance and replacement.
[0026] The unbonded prestressed steel strands 10 tighten the top longitudinal beam 6 and the middle column 5 through post-tensioning, so that the structural system can play a vertical bearing role under normal use conditions. Under normal circumstances, the unbonded prestressed steel strands 10 remain in a tensioned state, so that the dry joint between the middle column 5 and the top longitudinal beam 6 remains in close contact, ensuring the integrity of the station structure. Two bundles of unbonded prestressed steel strands 10 are set inside the middle column 5 and arranged symmetrically. This arrangement can ensure that the unbonded prestressed steel strands 10 are uniformly stressed inside the middle column 5, improve their restoring force and restraint effect under earthquake action, and avoid structural distortion or local stress concentration due to uneven stress on one side.
[0027] When an earthquake occurs, when the horizontal shear force borne by the middle column 5 reaches the friction force required for sliding at the dry joint, the top longitudinal beam 6 and the middle column 5 begin to shift relative to each other. Since the connection method between the middle column 5 and the top longitudinal beam 6 adopts a dry joint design and the longitudinal reinforcement is disconnected, when the horizontal shear force exceeds the static friction force of the joint under the action of an earthquake, relative slip will occur between the two, thereby avoiding the brittle failure of the middle column 5 due to excessive shear force under the traditional rigid connection method. This shifting mechanism enables the middle column 5 to adapt to the foundation deformation during an earthquake to a certain extent and reduce the stress concentration inside the structure. The relative shifting will continue until the structural deformation reaches the maximum value, at which time the unbonded prestressed steel strand 10 provides a restoring force so that the shifting between the two is not too large and provides a certain recovery trend. The characteristic of the unbonded prestressed steel strand 10 is that it can provide additional tension after the structure is deformed, thereby helping the top longitudinal beam 6 and the middle column 5 to gradually return to their original positions, reducing the residual deformation of the structure and improving the post-earthquake performance. At the same time, the restoring force of the unbonded prestressed steel strands 10 can also effectively prevent the middle column 5 from undergoing excessive lateral displacement during an earthquake, ensuring that it can still play a vertical bearing role and avoiding further damage to the subway station structure due to the failure of the middle column 5.
[0028] In this embodiment, the bottom of the top longitudinal beam 6 and the outer surface of the top of the middle column 5 are both provided with an outer protective steel plate 11 to prevent local concrete pressure damage during an earthquake. Since relative displacement may occur between the top longitudinal beam 6 and the middle column 5 during an earthquake, the concrete surface is prone to local crushing during the stress process, and the provision of the outer protective steel plate 11 can effectively disperse stress and improve the durability and earthquake resistance of key parts. Furthermore, the outer protective steel plate 11 is fixed to the top longitudinal beam 6 and the middle column 5 with bolts. This connection method is convenient for construction and installation, and can be disassembled, replaced or maintained after the earthquake, thereby improving the maintainability of the structure.
[0029] Structural reserved grooves 12 are provided on the sides of the top longitudinal beam 6 and the bottom longitudinal beam 8 for re-tensioning or replacing the unbonded prestressed steel strands 10 after an earthquake. When the tensioning force of the unbonded prestressed steel strands 10 is attenuated or damaged due to an earthquake, subsequent maintenance can be carried out through the structural reserved grooves 12 without destroying the original structure, thereby greatly improving the service life and safety of the structure. The unbonded prestressed steel strands 10 are protected by bellows 9 to prevent the steel strands from being damaged during construction and use. The function of the bellows 9 is to isolate the steel strands from the concrete, allowing the steel strands 10 to slide freely during the stress process, while reducing the damage that may be caused to the steel strands 10 during the construction phase, thereby improving the reliability of the prestressed system.
[0030] Furthermore, the unbonded prestressed steel strand 10 can be arranged in a curve. Compared with the straight line arrangement, the curve arrangement can provide more flexible recovery ability under the action of earthquake, so that the seismic effect of the structure is further optimized. The bottom and top of the unbonded prestressed steel strand 10 are anchored by the tensioning end 13 and the fixed end 14 respectively, ensuring the reliable transmission of prestress and facilitating subsequent tensioning adjustment. The tensioning end 13 and the fixed end 14 are respectively located inside the structural reserved groove 12. This design facilitates post-earthquake maintenance operations, so that the unbonded prestressed steel strand 10 can be re-tensioned or replaced without affecting the normal use of the station, ensuring the long-term stability and safety of the station structure.
[0031] In summary, the present invention discloses a seismic toughness structural system for a subway station, comprising a top plate 1, a middle plate 2, a bottom plate 3, a side wall 4 and a middle column 5, which constitute the basic structural frame of the subway station. The longitudinal reinforcement between the top of the middle column 5 and the top longitudinal beam 6 is disconnected to form a dry joint. Two bundles of post-tensioned unbonded prestressed steel strands 10 pass through the dry joint, with the top anchored to the side of the top longitudinal beam 6 and the bottom anchored to the side of the bottom longitudinal beam 8, and the top longitudinal beam 6 and the middle column 5 are kept tightly connected by post-tensioned prestressing. When an earthquake occurs, when the horizontal shear force of the middle column 5 reaches the sliding friction force of the dry joint, relative displacement occurs between the top longitudinal beam 6 and the middle column 5 until the structural deformation reaches the maximum value. The unbonded prestressed steel strands 10 provide restoring force, limit the displacement amplitude and promote recovery, and ensure the vertical bearing capacity of the middle column 5. The present invention improves the seismic toughness of the subway station structure by adopting a design of dry joints combined with post-tensioned unbonded prestressed steel strands 10. By cutting off the path for the horizontal earthquake load to be directly transmitted to the middle column 5, the damage to the middle column 5 caused by the earthquake is reduced, and the unbonded prestressed steel strands 10 are used to provide a restoring force, so that the displacement under the earthquake is controlled and restored to a near original state after the earthquake, thereby ensuring the vertical bearing capacity of the middle column 5. The structural design of the present invention not only improves the deformation adaptability during an earthquake, but also can quickly recover after an earthquake, thereby improving the seismic safety and recoverability of the subway station.
[0032] The invention has a simple structure, convenient construction, strong economy, good earthquake resistance and self-recovery ability, conforms to the design concept of underground structural toughness, and provides an efficient and reliable solution for the earthquake resistance design of rail transit infrastructure. The implementation of the invention can effectively reduce the impact of earthquake disasters on subway stations, improve the availability of post-earthquake structures, reduce post-disaster maintenance costs, and extend the service life of stations, which is of great significance for ensuring the safe and stable operation of urban rail transit systems.
[0033] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may also be combined, the steps may be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the above embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the above embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A subway station seismic toughness structural system, characterized in that: The invention comprises a top plate (1), a middle plate (2), a bottom plate (3) and a side wall (4), which constitute the basic structural frame of a subway station; a middle column (5) is arranged between the top plate (1) and the bottom plate (3); a top longitudinal beam (6) is arranged below the top plate (1); a middle longitudinal beam (7) is arranged below the middle plate (2); a bottom longitudinal beam (8) is arranged above the bottom plate (3); the column bottom of the middle column (5) is rigidly connected to the bottom longitudinal beam (8); the longitudinal reinforcement between the column top of the middle column (5) and the top longitudinal beam (6) is disconnected to form a dry joint; two bundles of post-tensioned unbonded prestressed steel strands (10) pass through the dry joint; the top of the unbonded prestressed steel strands (10) are anchored to the side of the top longitudinal beam (6), and the bottom is anchored to the side of the bottom longitudinal beam (8); The unbonded prestressed steel strands (10) tighten the top longitudinal beam (6) and the center column (5) through post-tensioning prestressing, so that the structural system can play a vertical bearing role under normal use conditions.
2. The seismic toughness structural system of a subway station according to claim 1, characterized in that: When an earthquake occurs, when the horizontal shear force borne by the middle column (5) reaches the friction force required for sliding at the dry joint, the top longitudinal beam (6) and the middle column (5) begin to shift relative to each other until the structural deformation reaches a maximum value. At this time, the unbonded prestressed steel strands (10) provide a restoring force to prevent the shift between the two from being too large and provide a certain recovery trend to avoid affecting the vertical bearing capacity of the middle column (5).
3. The seismic toughness structural system of a subway station according to claim 2, characterized in that: Two bundles of the unbonded prestressed steel strands (10) are arranged inside the center column (5) and are symmetrically arranged.
4. The seismic toughness structural system of a subway station according to claim 3, characterized in that: The bottom of the top longitudinal beam (6) and the outer surface of the top of the middle column (5) are both provided with an outer protective steel plate (11) for preventing local pressure damage to the concrete during an earthquake.
5. The seismic toughness structural system of a subway station according to claim 4, characterized in that: The outer protective steel plate (11) is connected and fixed to the top longitudinal beam (6) and the center column (5) by means of bolts.
6. The seismic toughness structural system of a subway station according to claim 4 or 5, characterized in that: The side surfaces of the top longitudinal beam (6) and the bottom longitudinal beam (8) are provided with structural reserved grooves (12) for re-tensioning or replacing the unbonded prestressed steel strands (10) after an earthquake.
7. The seismic toughness structural system of a subway station according to claim 6, characterized in that: The unbonded prestressed steel strand (10) is protected by a corrugated tube (9) to prevent the steel strand from being damaged during construction and use.
8. The seismic toughness structural system of a subway station according to claim 7, characterized in that: The unbonded prestressed steel strands (10) are arranged in a curve.
9. The seismic toughness structural system of a subway station according to claim 8, characterized in that: The bottom and top of the unbonded prestressed steel strand (10) are anchored respectively via a tensioning end (13) and a fixing end (14).
10. The seismic toughness structural system of a subway station according to claim 9, characterized in that: The tensioning end (13) and the fixing end (14) are respectively located inside the structural reserved groove (12).