An assembled subway station shock absorption structure, shock early warning method and system

Abstract

The application relates to an assembled subway station damping structure, a vibration early warning method and system, which comprises prefabricated subway station lining structure components, prefabricated damping middle columns and prefabricated damping middle column bases, the prefabricated subway station lining structure components are connected through post-poured damping joints, the prefabricated subway station lining structure components comprise prefabricated side walls and prefabricated damping plates, the post-poured damping joints are poured through fiber reinforced composite materials and comprise shape memory alloy (SMA) bars and post-poured segment reinforcing steels; the prefabricated damping middle columns are inserted with the prefabricated damping middle column bases through shape memory alloy (SMA) bars, the prefabricated damping middle column bases are connected with the prefabricated damping plates through high-strength bolts, and dampers are arranged between the prefabricated damping middle column bases and the prefabricated damping plates. Compared with the prior art, the application comprehensively considers material characteristics, shock absorption and structural characteristics, shock absorption, and reduces the operation risk and operation cost of the subway station under the action of earthquakes.

Description

Technical Field

[0001] This invention belongs to the field of structural engineering technology, and in particular relates to a prefabricated subway station vibration reduction structure, vibration early warning method and system. Background Technology

[0002] In recent years, prefabricated modular structures have been widely promoted, and prefabricated subway stations have begun to be gradually applied in my country's rail transit engineering construction. Studies have shown that underground structures can also collapse due to earthquakes. Prefabrication technology allows the construction of damping layers, damping components, and other processes to be completed in the factory in advance, and then assembled on site. This gives prefabricated modular structures a significant advantage in terms of vibration reduction design and construction.

[0003] Chinese invention patent CN109853636B discloses a self-resetting vibration damping structure for prefabricated subway station central columns and arc-shaped rubber bearings. It employs a mortise and tenon structure to connect the prefabricated central column to the prefabricated top and bottom slabs. Under seismic action, the bending moment at the connection points between the central column and the station's top and bottom slabs is released, reducing damage to the station. The use of prefabricated steel-cylinder concrete central columns significantly improves their strength, reduces deformation, and enhances their seismic resistance. However, hinged connections generally have lower load-bearing capacity than rigid connections, and traditional concrete materials may suffer from cracking, spalling, and significant residual deformation. Therefore, to realize the application of prefabricated damping layers and structures in actual prefabricated subway station projects, it is urgent to design a vibration damping structure scheme suitable for prefabricated subway stations based on the theories of material property-based vibration reduction and isolation, and structural property-based vibration reduction and isolation, while also facilitating post-earthquake repair and ensuring sustainable use. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology by providing a prefabricated subway station vibration reduction structure, vibration early warning method and system, which comprehensively considers material properties for vibration reduction and isolation as well as structural properties for vibration reduction and isolation, thereby reducing the operational risks and costs of subway stations under seismic action.

[0005] The objective of this invention can be achieved through the following technical solutions: A prefabricated subway station vibration damping structure includes prefabricated subway station lining structural components, prefabricated vibration damping central columns, and prefabricated vibration damping central column bases. The precast subway station lining structural components are connected by post-cast vibration damping nodes. The precast subway station lining structural components include precast side walls and precast vibration damping plates. The precast vibration damping plates include precast top plates, precast middle plates and precast bottom plates. The post-cast vibration damping nodes are cast using fiber-reinforced composite materials and have embedded shape memory alloy SMA reinforcement and post-cast section reinforcement inside. The prefabricated damping column and the prefabricated damping column base are connected by shape memory alloy SMA reinforcement. The prefabricated damping column base is connected to the prefabricated damping plate by high-strength bolts. A damper is provided between the prefabricated damping column base and the prefabricated damping plate.

[0006] Furthermore, the precast top slab, the precast middle slab, and the precast bottom slab all include an EPS concrete layer and a high-damping concrete layer.

[0007] Furthermore, the high-damping concrete layer comprises high-damping concrete and reinforcing steel.

[0008] Furthermore, the fiber-reinforced composite material includes a matrix material and reinforcing fibers. The matrix material is an engineering cement-based composite material (ECC), and the reinforcing fibers include one or more of steel fibers, polypropylene fibers, cement, fly ash, ceramsite, and quartz sand.

[0009] Furthermore, the post-cast section reinforcing bars are connected to the shape memory alloy SMA reinforcing bars via sleeves.

[0010] Furthermore, damping rubber and damping springs are provided between the prefabricated damping column base and the prefabricated damping plate.

[0011] The present invention also provides a vibration early warning method based on the above-mentioned prefabricated subway station vibration reduction structure, comprising the following steps: Sensors are installed at the intersections of the precast sidewalls and the precast top slab, the precast middle slab and the precast bottom slab, and the precast damping columns. It receives monitoring data from various sensors and issues an early warning signal when structural deformation or internal force exceeds the safety threshold. Upon receiving the warning signal, replace or update the damaged components.

[0012] Furthermore, the sensors include a rebar gauge, a strain gauge, and a stress-free gauge, all of which are wireless sensors.

[0013] Furthermore, repeaters are embedded in the precast slab to transmit and receive monitoring data from various sensors.

[0014] The present invention also provides a vibration early warning system including the above-mentioned prefabricated subway station vibration reduction structure, and further includes: The monitoring module includes multiple sensors installed at the intersections of the precast side walls and the precast top slab, the precast middle slab and the precast bottom slab, and the precast damping columns, to monitor the real-time status of various parts of the structure. The early warning module receives monitoring data from various sensors, analyzes and judges whether the structure is deformed and whether the internal force exceeds the safety threshold, and issues an early warning signal based on the judgment result.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. In this invention, the post-cast damping node is cast using fiber-reinforced composite material, including shape memory alloy SMA reinforcement and post-cast section steel bars. The precast damping column and the precast damping column base are connected by shape memory alloy SMA reinforcement. The precast damping column base is connected to the precast damping plate by high-strength bolts. A damper is installed between the precast damping column base and the precast damping plate. By comprehensively considering the material properties for damping and isolation and the structural properties for damping and isolation to absorb seismic wave energy, this invention solves the problems of high cost, long construction period, poor constructability, and irreparability in conventional subway station damping design. It effectively reduces the operational risks and costs of subway stations under seismic action, and achieves efficient and green construction of urban underground stations.

[0016] 2. In this invention, the precast top slab, precast middle slab, and precast bottom slab all include an EPS concrete layer and a high-damping concrete layer. Compared with ordinary concrete, EPS concrete has a lower density, lighter weight, and better thermal insulation and sound insulation performance. High-damping concrete has high flexural strength, splitting tensile strength, and long-term durability. By using the above two materials, the early shrinkage and seismic resistance of the structure can be further improved.

[0017] 3. This invention is convenient to construct and simple to install. After earthquake damage, the damaged parts can be updated and replaced. It is repairable and recyclable, and has obvious price, environmental and time advantages compared with on-site shock absorption measures. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the left half of the cross-section of the vibration damping structure for a prefabricated subway station. The components include: 1. Precast top slab; 2. Precast middle slab; 3. Precast bottom slab; 4. Reinforcing steel; 5. Post-cast damping joint; 6. Precast damping column; 7. Precast damping column base; 8. High-strength bolts; 9. Dampers; 10. Precast sidewalls; 11. Sensors; 12. Shape memory alloy SMA reinforcement; 13. Early warning device. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0020] Example 1 This embodiment provides a prefabricated subway station vibration damping structure, such as Figure 1As shown, the structure includes precast subway station lining components, precast damping columns 6, and precast damping column bases 7. The precast subway station lining components include precast side walls 10 and precast damping slabs. The precast damping slabs include precast top slabs 1, precast middle slabs 2, and precast bottom slabs 3. Each of the precast top slabs 1, 2, and 3 includes an EPS concrete layer and a high-damping concrete layer. The high-damping concrete layer includes high-damping concrete and reinforcing steel bars 4. EPS concrete is a lightweight aggregate concrete composed of organic and inorganic materials. Compared with ordinary concrete, it has a lower density, lighter weight, and superior thermal insulation and sound insulation properties. It can significantly reduce building energy consumption while also reducing the structural weight. High-damping concrete is obtained by adding high-damping materials (polymers) to ordinary concrete. Adding high-damping materials to concrete can improve its workability. After adding polymers, the flexural strength, splitting tensile strength, and long-term durability of the concrete are higher than those of the reference concrete. By using the above two materials, the impact resistance, early shrinkage, impermeability, and frost resistance of concrete and its reinforced components can be further improved.

[0021] The precast side wall 10 is connected to the precast top slab 1, precast middle slab 2 and precast bottom slab 3 through the post-cast damping node 5. The post-cast damping node 5 is cast with fiber reinforced composite material and has shape memory alloy SMA reinforcement 12 and post-cast section reinforcement embedded inside. The post-cast section reinforcement is connected to the shape memory alloy SMA reinforcement 12 through a sleeve. The use of sleeve to replace the traditional welding process makes the connection of the building reinforcement more robust. At the same time, there is no actual operation with fire, which improves the safety of building construction. Fiber-reinforced composites consist of a matrix material and reinforcing fibers. The matrix material is engineering-grade cement-based composite material (ECC). Compared to traditional concrete, ECC offers advantages such as light weight, good toughness, high tensile strength, fine and dense crack formation, and excellent ductility. The reinforcing fibers include one or more of steel fibers, polypropylene fibers, cement, fly ash, ceramsite, and quartz sand. SMA (Solid Molecular Weighted Abrasive) is a smart material with shape memory effect, superelasticity, and self-healing capabilities. Its recoverable strain can reach 6%-8%, far exceeding the 0.2% of ordinary steel reinforcement, effectively improving the displacement ductility of the structure. Combining the characteristics of SMA and fiber-reinforced composites can solve the problems of concrete cracking, spalling, and large residual deformation, enabling cracks to heal to a certain extent. Using these two materials in the plastic hinge zone of frame joints significantly reduces the degree of damage and residual displacement. The prefabricated damping column 6 and the prefabricated damping column base 7 are connected by shape memory alloy SMA reinforcement 12. The prefabricated damping column base 7 is connected to the prefabricated damping plate by high-strength bolts 8. A damper 9, damping rubber and damping spring are installed between the prefabricated damping column base 7 and the prefabricated damping plate. When an earthquake occurs, the vibration amplitude can be reduced and the stability of the structure can be improved.

[0022] Example 2 This embodiment provides a vibration early warning method for a prefabricated subway station vibration reduction structure based on Embodiment 1, including the following steps: S1. Sensors 11 are installed at the intersections of the precast sidewall 10 with the precast top slab 1, the precast middle slab 2 and the precast bottom slab 3, as well as the precast damping column 6. The sensors 11 include steel gauges, strain gauges and stress gauges, all of which are wireless sensors. A repeater is embedded in the precast middle slab 2 to receive and transmit the monitoring data of each sensor. S2. Receive monitoring data from each sensor. When structural deformation is detected and the internal force is greater than the safety threshold, issue a first warning signal, the warning light of the warning device 13 turns red and an alarm sounds; when structural deformation is detected and the internal force is less than the safety threshold, issue a second warning signal, the warning light of the warning device 13 turns green.

[0023] S3. After receiving the warning signal, replace or update the damaged parts. Taking the center column as an example, the steps include: (1) Remove the high-strength bolts 8 connecting the precast damping column base 7 and the precast damping plate; (2) Remove the prefabricated shock-absorbing central column base 7; (3) Remove the damaged precast damping column 6; (4) Replace the precast damping center column 6; (5) Install the new prefabricated shock-absorbing center column base 7; (6) Connect the new prefabricated damping column base 7 to the prefabricated damping plate with high-strength bolts 8.

[0024] This method is convenient to construct and simple to install. After an earthquake, damaged components can be replaced, making it repairable and recyclable. Compared with on-site vibration reduction measures, it has significant advantages in price, environmental protection, and time.

[0025] Example 3 This embodiment provides a vibration early warning system for a prefabricated subway station vibration reduction structure, including the system described in Embodiment 1, and further includes: The monitoring module includes multiple sensors 11 respectively installed at the intersection of the precast side wall 10 and the precast top slab 1, the precast middle slab 2 and the precast bottom slab 3, and the precast damping column 6, for monitoring the real-time status of various parts of the structure. It also includes a repeater embedded in the precast middle slab 2 for receiving and transmitting monitoring data from each sensor. The early warning module receives monitoring data from various sensors, analyzes and judges whether the structure is deformed and whether the internal force is greater than the safety threshold, and issues an early warning signal based on the judgment result. When structural deformation is detected and the internal force is greater than the safety threshold, a first early warning signal is issued. When the first early warning signal is received, the warning light of the early warning device 13 turns red and an alarm sounds. When structural deformation is detected and the internal force is less than the safety threshold, a second early warning signal is issued. When the second early warning signal is received, the warning light of the early warning device 13 turns green.

[0026] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A prefabricated subway station vibration damping structure, characterized in that, It includes prefabricated subway station lining structural components, prefabricated damping columns (6) and prefabricated damping column bases (7). The precast subway station lining structure components are connected by post-cast damping nodes (5). The precast subway station lining structure components include precast side walls (10) and precast damping plates. The precast damping plates include precast top plates (1), precast middle plates (2) and precast bottom plates (3). The post-cast damping nodes (5) are cast by fiber reinforced composite materials and are internally embedded with shape memory alloy SMA reinforcement (12) and post-cast section reinforcement. The prefabricated damping column (6) and the prefabricated damping column base (7) are connected by shape memory alloy SMA reinforcement (12). The prefabricated damping column base (7) is connected to the prefabricated damping plate by high-strength bolts (8). A damper (9) is provided between the prefabricated damping column base (7) and the prefabricated damping plate. The precast top slab (1), the precast middle slab (2) and the precast bottom slab (3) all include an EPS concrete layer and a high-damping concrete layer; The high-damping concrete layer includes high-damping concrete and reinforcing steel (4). The fiber-reinforced composite material includes a matrix material and reinforcing fibers. The matrix material is an engineering cement-based composite material (ECC), and the reinforcing fibers include steel fibers and / or polypropylene fibers. Fiber-reinforced composites also include one or more of cement, fly ash, ceramsite, and quartz sand.

2. The prefabricated subway station vibration damping structure according to claim 1, characterized in that, The post-cast section reinforcement is connected to the shape memory alloy SMA reinforcement (12) through a sleeve.

3. The prefabricated subway station vibration damping structure according to claim 1, characterized in that, A damping rubber and a damping spring are provided between the prefabricated damping column base (7) and the prefabricated damping plate.

4. A vibration early warning method based on the prefabricated subway station vibration reduction structure as described in any one of claims 1-3, characterized in that, Includes the following steps: Sensors (11) are installed at the intersections of the precast sidewall (10) with the precast top slab (1), the precast middle slab (2) and the precast bottom slab (3) and at the precast damping column (6). It receives monitoring data from various sensors and issues an early warning signal when structural deformation or internal force exceeds the safety threshold. Upon receiving the warning signal, replace or update the damaged components.

5. The vibration early warning method according to claim 4, characterized in that, The sensors include a rebar gauge, a strain gauge, and a stress-free gauge, all of which are wireless sensors.

6. The vibration early warning method according to claim 5, characterized in that, A repeater is embedded in the precast slab (2) to receive and transmit monitoring data from each sensor.

7. A vibration early warning system comprising a prefabricated subway station vibration damping structure as described in any one of claims 1-3, characterized in that, Also includes: The monitoring module includes multiple sensors respectively installed at the intersection of the precast sidewall (10) and the precast top slab (1), the precast middle slab (2) and the precast bottom slab (3), and the precast damping column (6) to monitor the real-time status of various parts of the structure. The early warning module receives monitoring data from various sensors, analyzes and judges whether the structure is deformed and whether the internal force exceeds the safety threshold, and issues an early warning signal based on the judgment result.

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