Partial assembly type subway station anti-seismic structure based on shape memory alloy

Abstract

The utility model discloses a local assembly type subway station anti-seismic structure based on shape memory alloy. The local assembly type subway station anti-seismic structure is characterized by comprising a bottom plate, side walls, a top plate and prefabricated middle columns. The bottom plate, the side walls and the top plate are cast-in-place components. The side wall is vertically poured on the side edge of the bottom plate; a plurality of post-pouring holes are reserved in the bottom plate; the prefabricated middle column is located in the post-pouring hole and is vertically and fixedly connected with the bottom plate; the top plate is arranged at the tops of the prefabricated middle column and the side walls. The prefabricated middle column is a reinforced concrete member and comprises conventional vertical steel bars and shape memory alloy. The shape memory alloy is wound around the periphery of the vertical steel bar, and the two ends of the shape memory alloy are fixed in the prefabricated middle column. The prefabricated center pillar further comprises a heating assembly. One end of the heating assembly is connected with the shape memory alloy; the heating assembly is used for being connected with an external power source so as to heat the shape memory alloy. According to the structure, the waterproof performance of the subway station anti-seismic structure is improved, and the anti-seismic performance and the post-earthquake recovery capacity of the subway station anti-seismic structure are improved.

Description

Technical Field

[0001] This utility model relates to the field of seismic resistance technology for subway station building structures, and in particular to a partially prefabricated seismic resistance structure for subway stations based on shape memory alloys. Background Technology

[0002] Subways are one of the basic transportation facilities for people's daily travel. Therefore, ensuring that subway stations have high seismic performance and post-earthquake recovery capabilities is particularly important for protecting public safety and ensuring the stable operation of production and daily life. For existing subway station seismic-resistant structures, especially for typical double-span structures, the dynamic response characteristics of the central column, which is prone to large displacement and rotation, have always been a weak point in the structure's seismic performance. In addition, existing subway stations mainly adopt prefabricated structures, that is, different structural components of the subway station are prefabricated in the factory and transported to the construction site for on-site assembly. However, prefabricated structures have many splicing nodes, which are prone to leakage during the station's service life. This not only increases subsequent operation and maintenance costs but also reduces the service life of the structure. Therefore, to address the above problems, this utility model proposes a partially prefabricated seismic-resistant subway station structure based on shape memory alloy, in order to improve both the seismic performance and waterproofing effect of the structure. Utility Model Content

[0003] The main technical problem to be solved by this utility model is to provide a seismic-resistant structure for subway stations, so as to improve the seismic performance and waterproof performance of existing structures at the same time.

[0004] To solve the above-mentioned technical problems, this utility model provides a partially prefabricated seismic-resistant structure for subway stations based on shape memory alloys, including a base plate, side walls, a top plate, and prefabricated central columns.

[0005] The base slab, side walls, and top slab are cast-in-place components.

[0006] The sidewall is vertically installed on the side of the base plate; the base plate has several pre-reserved post-pouring holes; the precast central column is located in the post-pouring holes and is vertically fixed to the base plate;

[0007] The top slab is located on top of the precast central column and the side wall;

[0008] The precast central column is a reinforced concrete component, including conventional vertical steel bars and shape memory alloy; the shape memory alloy is wrapped around the outer periphery of the vertical steel bars, and both ends are fixed inside the precast central column;

[0009] The prefabricated central column also includes a heating component; one end of the heating component is connected to the shape memory alloy, and the other end is exposed on the surface of the prefabricated central column; the heating component is used to connect an external power source to heat the shape memory alloy.

[0010] In a preferred embodiment, the prefabricated center column further includes a temperature monitoring component; the temperature monitoring component includes a temperature sensor and a display screen;

[0011] The temperature sensor is embedded in the prefabricated central column and connected to the shape memory alloy;

[0012] The display screen is connected to the temperature sensor and exposed on the surface of the precast central column to provide real-time feedback of temperature monitoring data.

[0013] In a preferred embodiment, the base plate, side walls, and top plate are constructed using high-toughness cement-based composite concrete.

[0014] In a preferred embodiment, the system further includes a column pier and a column cap; the column pier is cast post-cast at the connection between the precast central column and the base slab; the column cap is cast post-cast at the connection between the precast central column and the top slab.

[0015] In a preferred embodiment, the prefabricated center column further includes an anchor; the anchor is disposed at the end of the shape memory alloy to fix the shape memory alloy to the prefabricated center column.

[0016] In a preferred embodiment, the winding range of the shape memory alloy within the prefabricated central column is: within the section where the bottom of the prefabricated central column is 0.5m-1.0m from the bottom plate, and within the section where the top of the prefabricated central column is 0.5m-1.0m from the top plate.

[0017] In a preferred embodiment, the prefabricated central column further includes an insulation layer; the insulation layer covers the shape and the surface of the alloy.

[0018] In a preferred embodiment, the heating assembly includes a pre-embedded wire and an external plug; one end of the pre-embedded wire is connected to the shape memory alloy, and the other end is connected to the external plug.

[0019] In a preferred embodiment, the precast central column is provided with a concrete protective layer on the outside of the shape memory alloy.

[0020] In a preferred embodiment, the shape memory alloy is a NiTiNb shape memory alloy.

[0021] Compared with the prior art, the technical solution of this utility model has the following beneficial effects:

[0022] (1) The structure provided by this utility model has a base plate, side walls, and top plate, all of which are cast-in-place components. Compared with fully prefabricated subway station structures, it can effectively reduce splicing nodes and improve the waterproof performance of subway stations during operation. Furthermore, the structure uses high-toughness cement-based composite concrete, which has the characteristics of high toughness, high strength, and high durability, and can be flexibly selected according to different seismic fortification requirements, making the seismic performance of the structure superior to that of traditional reinforced concrete structures.

[0023] (2) The structure provided by this utility model has a prefabricated central column wound with the shape memory alloy. The shape memory alloy provides circumferential pressure to the prefabricated central column, thereby strengthening the structure and improving its seismic performance.

[0024] (3) Furthermore, if the precast central column develops structural defects during an earthquake, the column can be reinforced and repaired by heating the shape memory alloy; if the precast central column is severely damaged during an earthquake, its assembly-type connection with adjacent components allows it to be directly replaced, thereby quickly restoring support to the roof slab. Therefore, the structure provided by this utility model enables subway stations to resume operation promptly after an earthquake. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure described in the embodiments of this utility model;

[0026] Figure 2 This is a schematic diagram of the prefabricated central column described in an embodiment of this utility model.

[0027] The markings in the diagram are as follows: 1-base plate, 11-post-pouring hole, 2-side wall, 3-precast central column, 31-shape memory alloy, 32-bolt, 33-heating component, 331-embedded wire, 332-external plug, 34-insulation layer, 35-temperature monitoring component, 351-temperature sensor, 352-display screen, 36-concrete protective layer, 4-top plate, 5-column pier, 6-column cap. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0029] In the description of this utility model, it should be noted that the terms "upper" and "lower" are used interchangeably. "The orientation or positional relationship indicated by terms such as "inner," "outer," and "top / bottom" is based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of describing this utility model and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped with", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0031] like Figure 1 , Figure 2 As shown, this utility model embodiment provides a partially prefabricated seismic-resistant subway station structure based on shape memory alloy, including a base plate 1, side walls 2, a top plate 4, and prefabricated central columns 3.

[0032] like Figure 1As shown, both the base slab 1 and the side wall 2 are constructed using high-toughness cement-based composite (ECC) concrete, integrally cast. It is understood that the side wall 2 is vertically cast to the side of the base slab 1. The main components of the aforementioned high-toughness cement-based composite material are cement, fly ash, chopped polyethylene fibers, silica fume, and quartz sand, etc., and their specific components and proportions can be selected according to different seismic fortification requirements. Compared to traditional concrete, the high-toughness cement-based composite concrete possesses higher toughness, strength, and durability, resulting in better seismic performance of the structure. For ease of description, the high-toughness cement-based composite concrete will be referred to as ECC concrete below. The precast central column 3 is wound with shape memory alloy 31 and vertically installed on the base slab 1 through a pre-reserved post-casting hole 11. The top slab 4 is cast in place using the ECC concrete, with the tops of the side wall 2 and the precast central column 3 as supports. Compared to the prefabricated structures used in existing subway stations, the structure provided in this embodiment features a cast-in-place base slab 1, side walls 2, and top slab 4, significantly reducing splicing nodes and thus greatly mitigating leakage during subsequent use. To further improve connection stability and structural integrity, a conical column pier 5 is cast at the connection between the prefabricated central column 3 and the base slab 1, while a conical column cap 6 is cast at the connection with the top slab 4. Specifically, in this structure, the prefabricated central column 3's prefabricated connection with adjacent components allows it to be directly replaced after severe damage during an earthquake, quickly restoring support for the top slab 4 and enabling the subway station to resume operation promptly.

[0033] The precast central column 3 is a reinforced concrete structure. For example... Figure 2As shown, in addition to conventional steel bars and ordinary concrete, the precast central column 3 also includes a shape memory alloy 31, anchors, a heating assembly 33, a temperature monitoring assembly 35, and an insulation layer 34. The heating assembly 33 includes embedded wires 331 and an external plug 332, and the temperature monitoring assembly includes a temperature sensor 351 and a display screen 352. The shape memory alloy 31 is embedded within the precast central column 3. Specifically, the shape memory alloy 31 is cold-drawn to a cumulative pre-deformation of 5%-8%, then wound around the periphery of the vertical steel bars of the precast central column 3, and fixed at both ends of the wound section to the concrete of the precast central column 3 by the anchors. In this embodiment, the shape memory alloy 31 is made of NiTiNb shape memory alloy wire with a diameter of 2mm-5mm; the anchors are high-strength bolts 32. To balance practicality and economy, the shape memory alloy 31 is wound around the weakest points of the precast column 3, specifically within a section 0.5m-1.0m from the bottom of the column to the base plate 1 and a section 0.5m-1.0m from the top of the column to the top plate 4. For ease of description, these two winding sections will be referred to as the reinforcement sections below. Furthermore, the winding spacing of the shape memory alloy 31 is 1cm-5cm.

[0034] The insulation layer 34 wraps around the surface of the shape memory alloy 31 to ensure a stable temperature rise during heating. The embedded wire 331 is attached to the surface of the insulation layer 34, with one end connected to the shape memory alloy 31 and the other end connected to the external plug 332. It is understood that the insertion / removal surface of the external plug 332 is exposed on the surface of the prefabricated central column 3. When an external power supply is connected to the external connector, the shape memory alloy 31 can be heated via the embedded wire 331. The temperature sensor 351 is embedded in the prefabricated central column 3 and connected to the shape memory alloy 31 to monitor its temperature in real time during heating. If necessary, the temperature sensor 351 is also connected to a display screen 352 exposed on the surface of the prefabricated central column 3 to provide real-time feedback of the monitoring data. Monitoring the heating temperature of the shape memory alloy 31 not only provides real-time quantitative information for decisions such as insulation and power-off, but also prevents the shape memory alloy 31 from overheating. For example, the surface temperature of the NiTiNb shape memory alloy used in this embodiment should not exceed 200°C. Regarding the column structure, a concrete protective layer 36 with a thickness of 20mm-40mm is also applied around the outer periphery of the insulation layer 34 and the embedded wire 331.

[0035] The shape memory alloy 31 possesses a unique memory effect and high elasticity. After deformation under external force, its internal crystal structure can be reversed from a low-temperature martensitic phase to a high-temperature austenitic phase by heating, thus restoring its original shape. Therefore, the pre-stretched shape memory alloy 31 is wound and fixed to the prefabricated central column 3, and then its phase transformation is activated by electrical heating, causing it to shorten in length to restore its original shape. Since the two ends of the shape memory alloy 31 are constrained, this shortening tendency translates into a tightening effect on the prefabricated central column 3. In this way, the shape memory alloy 31 exerts circumferential pressure on the prefabricated central column 3, structurally reinforcing it. Furthermore, the surface of the prefabricated central column 3 has a pre-installed external plug 332. If the prefabricated central column 3 develops structural defects during an earthquake, the column can be reinforced and repaired by heating the shape memory alloy 31.

[0036] To further understand this technical solution, the construction and installation steps of the structure are briefly described below.

[0037] Step 1: Produce the precast central column 3 in the workshop. Pour and cure the core area of ​​the precast central column 3. Then, cold-draw the shape memory alloy 31 and wrap and fix it to the surface of the vertical reinforcing bars in the reinforced section of the precast central column 3. Next, wrap the insulation layer 34 around the surface of the shape memory alloy 31, and install the embedded wire 331, external plug 332, temperature sensor 351, and display screen 352. After the above components are installed, construct the concrete protective layer 36. It is necessary that the embedded wire 331 be stably connected to the shape memory alloy 31 and the external plug 332; the temperature sensor 351 should be in full contact with the shape memory alloy 31. The external connector and the display screen 352 should be exposed on the surface of the concrete protective layer 36.

[0038] Step 2: On-site pouring of the base slab 1 and side walls 2. The ECC concrete is prepared and the reinforcing bars are tied on-site, followed by pouring and curing of the base slab 1 and side walls 2. If necessary, post-pouring holes 11 should be pre-drilled in the base slab 1 according to the design drawings to provide a location for the installation of the precast central column 3.

[0039] Step 3: Heate the prefabricated central column 3 with electricity. Connect the external power supply to heat the shape memory alloy 31 in the prefabricated central column 3, and refer to the display screen 352 to slowly heat the latter at a rate of approximately 25°C per minute. When the temperature of the shape memory alloy 31 reaches 150°C, maintain this temperature for 20 minutes, and then disconnect the power. Note that the surface temperature of the shape memory alloy 31 should not exceed 200°C; therefore, the display screen 352 needs to be monitored constantly during the heating process to prevent overheating.

[0040] Step 4: Install the precast center column 3. Transport the precast center column 3, after it has been electrically heated, to the construction site and connect it to the base plate 1. Specifically, vertically insert the precast center column 3 into the pre-drilled post-pouring hole 11 on the base plate 1, and fill the post-pouring hole 11 with ECC concrete. Next, cast the column pier 5 at the connection point using ECC concrete to stably connect the precast center column 3 to the base plate 1.

[0041] Step 5: Casting the Top Slab 4. After the precast central column 3 is installed, the top is cast using the precast central column 3 and the top of the side wall 2 as supports. The top slab 4 is also cast using ECC concrete. Next, the column cap 6 is cast using ECC concrete at the column head to stably connect the precast central column 3 and the top slab 4.

[0042] The above description is merely a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All technically equivalent modifications made based on the content of the present utility model specification shall fall within the protection scope of the present utility model.

Claims

1. A partially prefabricated seismic-resistant structure for subway stations based on shape memory alloys, characterized in that: Includes the base slab, side walls, top slab, and precast central columns; The base slab, side walls, and top slab are cast-in-place components. The sidewall is vertically installed on the side of the base plate; the base plate has several pre-reserved post-pouring holes; the precast central column is located in the post-pouring holes and is vertically fixed to the base plate; The top slab is located on top of the precast central column and the side wall; The precast central column is a reinforced concrete component, including conventional vertical steel bars and shape memory alloy; the shape memory alloy is wrapped around the outer periphery of the vertical steel bars, and both ends are fixed inside the precast central column; The prefabricated central column also includes a heating component; one end of the heating component is connected to the shape memory alloy, and the other end is exposed on the surface of the prefabricated central column; the heating component is used to connect an external power source to heat the shape memory alloy.

2. The seismic-resistant structure of a partially prefabricated subway station based on shape memory alloy according to claim 1, characterized in that: The precast central column also includes a temperature monitoring component; the temperature monitoring component includes a temperature sensor and a display screen. The temperature sensor is embedded in the prefabricated central column and connected to the shape memory alloy; The display screen is connected to the temperature sensor and exposed on the surface of the precast central column to provide real-time feedback of temperature monitoring data.

3. The seismic-resistant structure of a partially prefabricated subway station based on shape memory alloy according to claim 1, characterized in that: The base plate, side walls, and top plate are constructed using high-toughness cement-based composite concrete.

4. The seismic-resistant structure of a partially prefabricated subway station based on shape memory alloy according to claim 1, characterized in that: It also includes column piers and column caps; the column piers are cast post-cast at the connection between the precast central column and the base slab; the column caps are cast post-cast at the connection between the precast central column and the top slab.

5. The seismic-resistant structure of a partially prefabricated subway station based on shape memory alloy according to claim 1, characterized in that: The prefabricated central column also includes anchors; the anchors are disposed at the ends of the shape memory alloy to fix the shape memory alloy to the prefabricated central column.

6. The seismic-resistant structure of a partially prefabricated subway station based on shape memory alloy according to claim 1, characterized in that: The winding range of the shape memory alloy within the precast central column is: within the section 0.5m-1.0m from the bottom of the precast central column to the bottom plate, and within the section 0.5m-1.0m from the top of the precast central column to the top plate.

7. The seismic-resistant structure of a partially prefabricated subway station based on shape memory alloy according to claim 1, characterized in that: The prefabricated central column also includes an insulation layer; the insulation layer wraps around the shape and the surface of the alloy.

8. The seismic-resistant structure of a partially prefabricated subway station based on shape memory alloy according to claim 1, characterized in that: The heating component includes a pre-embedded wire and an external plug; one end of the pre-embedded wire is connected to the shape memory alloy, and the other end is connected to the external plug.

9. A partially prefabricated seismic-resistant subway station structure based on shape memory alloy according to claim 1, characterized in that: The precast central column is protected by a layer of concrete on the outside of the shape memory alloy.

10. A partially prefabricated seismic-resistant subway station structure based on shape memory alloy according to any one of claims 1 to 9, characterized in that: The shape memory alloy is a NiTiNb shape memory alloy.

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