A full-precast assembled subway station splicing temporary steel support unit

Abstract

This utility model discloses a prefabricated modular temporary steel support unit for subway stations, comprising double H-shaped steel columns, a supporting steel plate located on top of the double H-shaped steel columns for contact and load bearing with the middle plate, a leveling component located between the supporting steel plate and the double H-shaped steel columns for height adjustment, a bottom connection structure connected to the pre-embedded steel plate, and a force transmission sensor for monitoring the stress state of the support. The supporting steel plate, leveling component, double H-shaped steel columns, and bottom connection structure sequentially form a force transmission path from the middle plate to the base, providing support, positioning, and stress monitoring and safety control during the hoisting and placement of the middle plate. The double H-shaped steel column support and modular layout perfectly match the middle plate support points, avoiding the middle plate deflection or space encroachment caused by improper spacing, and greatly improving the support performance.

Description

Technical Field

[0001] This utility model relates to the field of temporary support technology for subway station construction, specifically to a fully prefabricated assembled temporary steel support unit for subway stations. Background Technology

[0002] In the construction of rectangular prefabricated subway stations, the efficiency, precision, and process coordination of component assembly are crucial to project quality. Current technologies for prefabricated subway stations mostly employ a fully prefabricated component assembly mode. Temporary support designs are all geared towards the "fully prefabricated" condition, failing to consider the mixed construction scenario of "cast-in-place longitudinal beams in the first three rings + prefabricated middle slabs." Since the longitudinal beams in the first three rings are cast-in-place and subsequently poured together with the cast-in-place strip, temporary supports are required under the middle slab. However, existing temporary support schemes have the following significant drawbacks: (1) Poor adaptability: The existing temporary supports are mostly single-specification steel sections or steel pipes, which cannot match the spacing of the cast-in-place longitudinal beams and the stress requirements of the middle plate. This can easily lead to problems such as the middle plate deflecting due to excessive support spacing or the middle plate squeezing the subsequent assembly space due to insufficient spacing. (2) Low installation accuracy: The existing support is mostly "directly overlapped" with the bottom plate and middle plate. There is no special pre-embedded positioning structure. The support length error often exceeds 50mm and the plane warping error exceeds 30mm, resulting in a horizontal deviation of ≥8mm when the middle plate is assembled. Secondary adjustment is required, which prolongs the construction period. (3) Significant process interference: Existing supports are mostly fixed by full welding, which requires cutting during dismantling and is prone to damaging the pre-embedded structure of the base plate; Moreover, the connection between the support installation and the curing of the cast-in-place longitudinal beam and the assembly of the middle plate is chaotic, often resulting in situations such as "the middle plate cannot be hoisted due to the support not being in place" or "the support removal is delayed, affecting the subsequent construction of the longitudinal beam", which increases the construction period by 1-2 days for each link; (4) Insufficient stress stability: The existing welds connecting the support and the base plate are mostly Class III welds with a weld height of only 8-10mm. Under the load of the middle plate, the welds are prone to cracking. Moreover, there is no force transmission monitoring mechanism. When the support is removed, the sudden change in load can easily lead to local instability of the foundation pit.

[0003] Therefore, there is an urgent need for a temporary steel support unit for the middle plate that can adapt to the working conditions of the cast-in-place longitudinal beams in the first three rings, with high-precision positioning, low process interference, and stable stress. Utility Model Content

[0004] The purpose of this utility model is to provide a fully prefabricated assembly-type temporary steel support unit for subway stations, so as to solve the problem of the middle plate deflection or space occupation caused by the mismatch of existing support spacing.

[0005] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: A fully prefabricated assembled temporary steel support unit for subway stations includes double H-shaped steel columns, a supporting steel plate set on the top of the double H-shaped steel columns and used to bear the load in contact with the middle plate, a leveling component located between the supporting steel plate and the double H-shaped steel columns and used for height adjustment, a bottom connection structure connected to the pre-embedded steel plate, and a force transmission sensor for monitoring the stress state of the support. The supporting steel plate, leveling components, double H-shaped steel columns, and bottom connecting structure sequentially form a force transmission path from the middle plate to the base, providing support, positioning, and force monitoring and safety control during the hoisting and positioning of the middle plate.

[0006] Furthermore, the double-section H-beam steel column includes at least two column segments, and multiple column segments are spliced ​​and connected to form a whole. The ends of adjacent column segments are spliced ​​together in the column axis so that the spliced ​​double-section H-beam steel column forms a continuous double section in the axial direction and forms a top-down load-bearing path with the supporting steel plate and the bottom connection structure.

[0007] Furthermore, the column segment includes two H-beams, which are arranged side by side and fixedly connected by welding to form a whole; the top of the double H-beam column is welded to the supporting steel plate, and its bottom is welded to the embedded steel plate through the bottom connection structure, so that the double H-beam column is set as a pressure-bearing and stabilizing component between the supporting steel plate and the embedded steel plate.

[0008] Furthermore, the leveling assembly includes an adjustable screw located below the supporting steel plate and a locking nut for locking after leveling is completed. The adjustable screw is located between the supporting steel plate and the double H-shaped steel column and is arranged along the direction of the support force. It is used to make fine adjustments to the height of the supporting steel plate and lock it during the hoisting and positioning of the middle plate.

[0009] Furthermore, the bottom connecting structure is set opposite to the embedded steel plate and fixed by welding. The bottom connecting structure is fixedly connected to the double H-shaped steel column so that the vertical reaction force from the supporting steel plate is transmitted to the embedded steel plate through the double H-shaped steel column and the bottom connecting structure. At the same time, the bottom positioning of the support unit is achieved by the embedded steel plate.

[0010] Furthermore, force sensors are installed on the force transmission path formed by the supporting steel plate, the double H-shaped steel columns, and the bottom connecting structure. These sensors are used to monitor the support force in real time during the hoisting and positioning of the middle plate and are electrically connected to the display / alarm module.

[0011] The present invention has the following beneficial effects: The prefabricated assembly-type temporary steel support unit for subway stations provided by the present invention forms a short, straight, rigid and continuous force transmission path through the coaxial integrated arrangement of "supporting steel plate - leveling component - double H-shaped steel column - bottom connection structure - embedded steel plate". The top support realizes surface contact force, the leveling component provides repeatable micro-lifting and locking to ensure positioning accuracy, the double H-shaped steel column bears the main pressure and improves the overall stability, and the bottom and the embedded steel plate form positioning and reaction nodes. With the real-time monitoring and alarm / interlocking of the force transmission sensor, a safe closed loop is constructed from installation to dismantling. By using double H-shaped steel columns for support and modular layout to perfectly match the support points of the middle plate, the "sloping of the middle plate caused by improper spacing" or "space encroachment" can be avoided. In addition, this support unit is well adapted to the mixed construction of "cast-in-place longitudinal beams + precast slabs", significantly improving the levelness and alignment accuracy of the slab assembly, balancing the load at multiple support points, and reducing eccentricity and additional bending moments. At the same time, the segmented splicing facilitates transportation and rapid assembly and disassembly, and is reusable, reducing process interference and overall costs, while taking into account quality, schedule and safety. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the double-section H-shaped steel column structure in this utility model; Figure 3 This is a schematic diagram of the installation of this utility model; Figures 1 to 3 The reference numerals in the attached drawings are respectively: 1-double H-shaped steel column, 2-supporting steel plate, 3-leveling component, 4-embedded steel plate. Detailed Implementation

[0013] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0014] like Figures 1 to 3 As shown, a prefabricated temporary steel support unit for a subway station includes a double H-shaped steel column 1, a supporting steel plate 2 set on top of the double H-shaped steel column 1 for contacting and bearing the load with the middle plate, a leveling component 3 located between the supporting steel plate 2 and the double H-shaped steel column 1 for height adjustment, a bottom connection structure connected to a pre-embedded steel plate 4, and a force transmission sensor for monitoring the stress state of the support. The supporting steel plate 2, the leveling component 3, the double H-shaped steel column 1, and the bottom connection structure sequentially form a force transmission path from the middle plate to the base, so as to provide support, positioning, and realize stress monitoring and safety control during the hoisting and positioning of the middle plate.

[0015] In this embodiment, the double-section H-beam steel column 1 comprises at least two column segments, and multiple column segments are spliced ​​and connected to form a whole. The ends of adjacent column segments are butted together in the column axis so that the spliced ​​double-section H-beam steel column 1 forms a continuous double section in the axial direction and forms a top-down load-bearing path with the supporting steel plate 2 and the bottom connecting structure. The splicing method is welding. The double-section H-beam steel column 1 serves as the main bearing and stabilizing component, reliably transferring the upper load downwards. The double section makes the cross-sectional distribution more symmetrical and the moment of inertia larger, resulting in better bending / lateral displacement / buckling resistance than a single component. The segmented column splicing form facilitates transportation, hoisting, and rapid on-site assembly, while ensuring continuous axial force transmission after splicing.

[0016] The column segment comprises two H-beams, which are arranged side-by-side and welded together to form a whole. The top of the double-section H-beam column 1 is welded to the supporting steel plate 2, and its bottom is welded to the embedded steel plate 4 via a bottom connecting structure. Thus, the double-section H-beam column 1 serves as a load-bearing and stabilizing component between the supporting steel plate 2 and the embedded steel plate 4. Structural steel (such as Q355) is used to meet strength, weldability, and economic requirements.

[0017] In this embodiment, the supporting steel plate 2 is fixed to the top of the support unit, forming a surface contact support with the bottom surface of the middle plate, evenly transferring the self-weight of the middle plate and the temporary construction load to the leveling component 3 and the vertical bearing member. This arrangement can suppress local indentations and edge warping, improving the quality of assembly and fitting. The supporting steel plate 2 is a rectangular steel plate, using structural steel (such as Q355) consistent with the column, which facilitates welding into an integrated load-bearing node and improves the surface contact bearing stability. In addition, the supporting steel plate 2, in conjunction with the leveling component 3, can achieve slight height adjustments during the hoisting and leveling process, ultimately forming a supporting plane that matches the middle plate, improving installation accuracy and the matching degree of the subsequent pouring surface.

[0018] In this embodiment, the leveling component 3 includes an adjustable screw rod disposed below the supporting steel plate 2 and a locking nut for locking after leveling. The adjustable screw rod is located between the supporting steel plate 2 and the double-section H-shaped steel column 1 and is arranged along the direction of support force. It is used to fine-tune the height of the supporting steel plate 2 and lock it during the hoisting and positioning of the middle plate. During leveling, the adjustable screw rod is rotated in small angles and gradually using a socket or wrench. The helical lifting effect of the threaded pair converts the angular displacement into a small axial displacement, thereby enabling the supporting steel plate 2 to produce controllable up / down fine adjustments and achieve the correction of the middle plate elevation and levelness. After leveling, the locking nut is tightened so that it forms an axial preload with the supporting steel plate 2 (or transition seat) and is in contact with the end face. Through the self-locking and preload of the threaded inclined surface-end face friction, the screw rod rotation and micro-slippage are suppressed, achieving position locking and stiffness improvement. After locking, the screw rod, locking nut, supporting steel plate 2, and column top constitute an equivalent rigid node.

[0019] In this embodiment, the bottom connecting structure is positioned opposite to the embedded steel plate 4 and fixed by welding. The bottom connecting structure is fixedly connected to the double H-shaped steel column 1 so that the vertical reaction force from the supporting steel plate 2 is transmitted to the embedded steel plate 4 through the double H-shaped steel column 1 and the bottom connecting structure. At the same time, the embedded steel plate 4 is used to achieve the bottom positioning of the support unit. The bottom connecting structure is the welded connection interface between the bottom end of the double H-shaped steel column 1 and the embedded steel plate 4. Through this interface, the reaction force generated by the upper support is reliably transmitted to the bottom plate and the bottom positioning of the support unit is completed. The embedded steel plate 4 is first embedded in the bottom plate concrete according to the positioning layout. During the pre-embedding, it is welded and fixed to the bottom plate reinforcement to ensure that it does not shift after pouring. It is used as the positioning and force transmission interface. After hoisting into place, the bottom end of the double H-shaped steel column 1 and the embedded steel plate 4 are fixed together by welding (secondary weld) to form a continuous force link. This weld also serves as the cutting position for subsequent non-destructive demolition.

[0020] In this embodiment, a force transmission sensor is installed on the force transmission path formed by the supporting steel plate 2, the double-section H-shaped steel column 1, and the bottom connecting structure. It is used to monitor the support stress in real time during the hoisting and positioning of the middle plate and is electrically connected to the display / alarm module. Furthermore, the force transmission sensor is also electrically connected to the control system. During operation, the force transmission sensor collects and transmits support load / stress data in real time to the control system. Through analysis by the control system, when the stress reaches a set threshold, a stop command is issued to halt the hoisting process and prevent further loading that could lead to instability or damage.

[0021] When using this solution, the main steps are as follows: S1: Pre-embedded steel plate 4 precise positioning Before pouring the precast base slab, mark the installation position of the embedded steel plate 4 according to the detailed design drawings; use a laser line projector to calibrate the levelness of the steel plate (deviation ≤2mm), and weld the steel plate to the bottom layer of the base slab reinforcement (weld point spacing ≤150mm) to ensure that the steel plate does not shift after pouring. During the pouring of the base slab concrete, a dedicated person is responsible for monitoring to prevent the vibrator from hitting the steel plate. After the pouring is completed, the levelness of the steel plate is re-measured, and any deviations are corrected in a timely manner.

[0022] S2: Modular installation of steel columns Before hoisting the precast middle plate, start the installation of the steel columns: use a gantry crane to hoist the double H-shaped steel column 1 and align it with the bottom embedded steel plate 4 (to ensure that the support spacing matches the spacing of the longitudinal beams). Construction of the connection weld between the steel column and the embedded steel plate 4: Carbon dioxide gas shielded welding is used, the welding grade is level 2, the weld height is 15mm (the contact part of the component) and the weld width is 10mm (the side weld). After welding, a penetrant test (PT) is performed to ensure that there are no pores or cracks. Leveling component 3 adjustment: Fine-tune the height of the steel column by adjusting the top adjustable screw, and use a laser level to make the top supporting steel plates 2 of the 12 sets of supports on the same horizontal plane (levelness deviation ≤3mm). After adjustment, tighten the nuts.

[0023] S3: Mid-plate assembly and support stress monitoring Before the mid-plate is hoisted, pre-load monitoring is carried out using force transmission sensors (the load value is 50% of the mid-plate load) to confirm that the stress of the support weld is ≤235MPa (Q355 steel yield strength) and there is no abnormal deformation; The middle plate is hoisted by a gantry crane so that the bottom of the middle plate is in contact with the top supporting steel plate 2. The leveling component 3 is used to fine-tune the level of the middle plate (final deviation ≤ 3mm) to ensure that the flatness of the bottom of the middle plate matches the subsequent longitudinal beam pouring surface. After the middle plate is assembled, the support load is monitored in real time (the stress value is displayed by the central control system). When the load fluctuation is greater than 10%, an early warning is triggered to investigate the splicing of the middle plate or the support connection (to avoid abnormal loads affecting the structural integrity after the subsequent longitudinal beams are poured).

[0024] S4: Undamaged removal of supports (after the longitudinal beam and post-cast strip have been poured and the strength has met the requirements, to adapt to subsequent procedures). The longitudinal beams and post-cast strips of the first three rings were poured simultaneously, and the concrete strength reached 100% of the design value (≥C30, curing period ≥28 days). At the same time, after the bolts connecting the middle plate and the longitudinal beams were tightened to the required torque, the support was removed. Dismantling sequence: First loosen the locking nut of the top leveling component 3, then use oxygen arc cutting to cut the weld between the steel column and the embedded steel plate 4. Monitor the temperature of the base plate and longitudinal beam during cutting (≤150℃). After the dismantled steel columns are straightened for flatness, they can be reused in other station construction projects with similar conditions. The pre-embedded steel plate 4 is retained in the base plate as a reference point for subsequent structural reinforcement.

[0025] Additionally, it should be noted that components not described in detail in this article are existing technologies.

[0026] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A full-precast assembly type subway station splicing temporary steel support unit, characterized in that, It includes a double H-shaped steel column (1), a supporting steel plate (2) set on the top of the double H-shaped steel column (1) and used to contact the middle plate for bearing force, a leveling component (3) located between the supporting steel plate (2) and the double H-shaped steel column (1) for height adjustment, a bottom connection structure connected to the pre-embedded steel plate (4), and a force transmission sensor for monitoring the support stress state; The supporting steel plate (2), leveling component (3), double H-shaped steel column (1) and bottom connecting structure sequentially form a force transmission path from the middle plate to the base, so as to provide support, positioning and realize force monitoring and safety control during the hoisting and positioning of the middle plate.

2. The fully-precast assembled subway station temporary steel bracing unit according to claim 1, characterized in that, The double H-shaped steel column (1) includes at least two column segments, and multiple column segments are spliced ​​and connected to form a whole. The ends of adjacent column segments are spliced ​​together in the column axis so that the spliced ​​double H-shaped steel column (1) forms a continuous double section in the axial direction and forms a top-down load-bearing path with the supporting steel plate (2) and the bottom connection structure.

3. The prefabricated modular subway station assembly temporary steel support unit according to claim 2, characterized in that, The column segment includes two H-beams, which are arranged side by side and fixedly connected by welding to form a whole; The top of the double H-shaped steel column (1) is welded to the supporting steel plate (2), and its bottom is welded to the embedded steel plate (4) through the bottom connection structure, so that the double H-shaped steel column (1) is set between the supporting steel plate (2) and the embedded steel plate (4) as a pressure-bearing and stabilizing component.

4. The prefabricated modular subway station assembly temporary steel support unit according to claim 1, characterized in that, The leveling component (3) includes an adjustable screw located below the supporting steel plate (2) and a locking nut for locking after leveling. The adjustable screw is located between the supporting steel plate (2) and the double H-shaped steel column (1) and is arranged along the direction of the support force. It is used to finely adjust the height of the supporting steel plate (2) and lock it during the hoisting and positioning of the middle plate.

5. The prefabricated modular temporary steel support unit for subway stations according to any one of claims 1 to 3, characterized in that, The bottom connecting structure is set opposite to the embedded steel plate (4) and fixed by welding. The bottom connecting structure is fixedly connected to the double H-shaped steel column (1) so that the vertical reaction force from the supporting steel plate (2) is transmitted to the embedded steel plate (4) through the double H-shaped steel column (1) and the bottom connecting structure. At the same time, the bottom positioning of the support unit is achieved by the embedded steel plate (4).

6. The prefabricated modular subway station assembly temporary steel support unit according to claim 1, characterized in that, The force transmission sensor is installed on the force transmission path formed by the supporting steel plate (2), the double H-shaped steel column (1) and the bottom connecting structure. It is used to monitor the support force in real time during the hoisting and positioning of the middle plate and is electrically connected to the display / alarm module.

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