Steel bar temporary supporting frame body for large-section underpinning beam construction

Abstract

A steel bar temporary supporting frame body for large-section underpinning beam construction comprises a ring lock scaffold main body, a throwing support reinforcing system and a top bearing unit, and is characterized in that the ring lock scaffold main body comprises a row of ring lock frames erected on the two sides of an underpinning beam respectively, and the throwing support reinforcing system comprises throwing supports (10) which are arranged according to the principle of two spans and one set; according to the top bearing unit, a U-shaped support (6) with the adjustable height is adopted for the top of the disc buckle frame, channel steel (12) is placed on the U-shaped support (6) and used for supporting steel bars in the upper row, a jacking steel pipe (13) is adopted for jacking the channel steel (12) in a beam, and the distance between the jacking steel pipe (13) and the channel steel (12) is set to be 1200 mm. The steel bar temporary supporting frame body for large-section underpinning beam construction has the advantages that the material consumption is reduced, the lateral displacement resistance is enhanced, the overall stability is improved, the erecting efficiency is high, the construction period is shortened, the labor cost is reduced, temporary material waste is reduced, and the auxiliary cost is saved.

Description

Technical Field

[0001] The invention belongs to the technical field of construction engineering, and in particular relates to a temporary steel support frame for the construction of large-section underpinning beams. Background Art

[0002] In building structure reinforcement and renovation projects, the reinforcement construction of large-section underpinning beams often relies on temporary support frames to bear the deadweight of the steel bars and construction loads to ensure building safety during construction. Traditional support systems are mainly divided into the following two categories, but both have significant drawbacks: 1. Use a coupler-type or bowl-type steel pipe scaffolding to construct a full-height support (see "Safety Technical Specifications for Coupler-Type Steel Pipe Scaffolding in Construction" JGJ 130), forming a spatial grid structure through dense vertical and horizontal bars. However, this system has the following problems: (1) Insufficient bearing capacity: When the load of large-section support beam reinforcement is concentrated, the vertical bar spacing needs to be greatly reduced (e.g., ≤0.6m), resulting in a surge in material consumption and limited construction space; (2) Poor adaptability: It cannot directly support the upper row of reinforcement, and additional wooden planks or steel pads are required, which increases the process and cost.

[0003] 2. Use I-beams, H-beams, etc. as primary and secondary beams (see "Steel Structure Design Standard" GB 50017), and connect them by welding or high-strength bolts to form a rigid support frame. Although this system has a high bearing capacity, it has the following limitations: (1) Poor economic efficiency: The cost of steel materials is high, and the node welding or bolt pre-tightening process is complicated, with labor costs accounting for more than 40% of the total cost; (2) Low construction efficiency: The hoisting of heavy components and the detailed construction of nodes are time-consuming, making it difficult to meet the needs of projects with tight construction schedules; (3) Difficult quality control: Weld quality defects or loose bolts can easily cause node failure, requiring full non-destructive testing, further increasing costs.

[0004] The two traditional support systems mentioned above face the dilemma of high cost, low efficiency, and difficulty in control when constructing large-section underpinning beams. Furthermore, hybrid support solutions attempted by the industry (such as steel tube-section steel combinations) still suffer from issues such as incompatible joints and unclear load transfer paths. Therefore, there is an urgent need to develop a new temporary support system that combines high load-bearing capacity, rapid construction, and economic efficiency to meet the comprehensive safety, timeline, and cost requirements of modern underpinning projects. Summary of the Invention

[0005] The purpose of the present invention is to provide a new type of double-row disc-type scaffolding composite support for the construction of large-section replacement beams and temporary steel support frames.

[0006] To achieve the above objectives, the technical solution of the present invention is: A temporary steel support frame for the construction of large-section underpinning beams, comprising a main body of a buckle scaffold, a toss reinforcement system, and a top load-bearing unit, characterized by: The main body of the buckle scaffolding includes: a row of buckle frames on each side of the supporting beam, and a row of buckle frames is 200mm away from the beam edge; the vertical spacing of several buckle frame poles is 1200mm, and the step distance is 1.5m; the support frame has an adjustable height U-shaped support extending 600mm from the top horizontal pole of the buckle frame, and the exposed length of the screw rod is 300mm, and the adjustable support is inserted into the pole with a length of 150mm; the sweeping rod is 500mm away from the ground; the bottom of the pole adopts an adjustable base, and the exposed length of the adjustable base screw rod is 200mm. If The diameter of the dry screw is 36mm, and the length of the inserted vertical rod is 150mm. The horizontal rods, longitudinal rods, and transverse rods are fully distributed to ensure the joint rigidity. The connection method between the vertical rods and the horizontal rods is: "The vertical rods are welded with connecting plates every 500mm. The horizontal rod end fastener heads are inserted into the corresponding sockets on the connecting plates and fixed vertically with the joint pins." The connection method between the vertical rods and the diagonal rods is: "Special holes for diagonal rods are reserved on the vertical rod connecting plates. The end fastener heads of the diagonal rods are inserted and fixed vertically with the joint pins." The guy support reinforcement system includes: the guy supports are arranged according to the principle of "two spans and one set", with a horizontal spacing of 2×1200mm. The guy supports are double-locked with the plate-locked vertical poles by right-angle fasteners and rotating fasteners. The horizontal poles are double-locked with right-angle fasteners and rotating fasteners. The horizontal steel pipes are double-locked with the guy supports by right-angle fasteners and rotating fasteners. The ends of the guy supports are connected to the vertical pole node plates. The ground anchor points are reinforced by pouring a concrete cushion layer. The top load-bearing unit: the top of the buckle frame adopts an adjustable height U-shaped support, and the channel steel is placed on the U-shaped support to support the upper row of steel bars. The beam adopts a top support steel pipe to support the channel steel, and the spacing is set to 1200mm.

[0007] The temporary steel support frame for the construction of the large-section underpinning beam of the present invention can be further implemented by adopting the following technical measures.

[0008] The aforementioned temporary steel support frame for the construction of the large-section replacement beam, wherein the inclination angle of the said castor is strictly controlled at 50°-60°.

[0009] The aforementioned temporary steel support frame for the construction of large-section replacement beams has a horizontal projection length of the guy support that is ≤2.5 times the vertical distance of the vertical poles. When the vertical distance is 1.2m, the projection length is ≤3.0m.

[0010] After adopting the above technical solution, the temporary steel support frame for the construction of large-section underpinning beams of the present invention has the following advantages: 1. Reduced material usage, enhanced anti-lateral shift capability, and improved overall stability; 2. High erection efficiency, shortened construction period and reduced labor costs; 3. Reduce waste of temporary materials and save auxiliary costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A horizontal elevation view of a temporary support frame according to an embodiment of the present invention; Figure 2 It is a longitudinal elevation view of a temporary support frame according to an embodiment of the present invention. DETAILED DESCRIPTION

[0012] The present invention will be further described below with reference to the embodiments and the accompanying drawings.

[0013] Example 1 The application scope of the temporary steel support frame for the construction of large-section underpinning beams of the present invention is as follows: The present invention is suitable for the positioning and temporary bearing of steel bars in the construction of large-span and large-section reinforced concrete underpinning beams, especially for the underpinning projects of large-space buildings such as exhibition centers and transportation hubs. The specific application scope is as follows: 1): Cross-sectional dimensions: Suitable for underpinning beams with rectangular cross-sectional widths of 1.8-3.0m and heights of 2.0-3.5m (verified in five specifications, including 2m×2.5m and 2.5m×3.5m, covering aspect ratios of 0.8-1.75).

[0014] 2): Span range: single span is applicable to 8-25m, and extra-long span (25-32m) can be achieved by segmented erection, with segment spacing ≤16m (the 32m span support beam of the exhibition center is erected in two sections).

[0015] 3): Steel bar specifications: Suitable for HRB400E / HRB500E grade 3 threaded steel bars, main bar diameter ≤36mm (the bearing capacity requirements of layered binding of 36mm diameter steel bars have been verified).

[0016] 4): Applicable engineering scope: column base underpinning and load transfer of large-span spatial structures such as convention and exhibition centers, stadiums, and theaters; underpinning scenarios such as adding floors to historical buildings and expanding basements that need to avoid existing pipelines or foundations; local reinforcement support for multi-directional load-bearing underpinning beams (such as L-shaped and T-shaped sections) (customized bracing arrangement is required).

[0017] 5): Expansibility description: By adding intermediate support columns and upgrading channel steel, it can meet the adaptability of larger cross-sections; if steel bars with a diameter greater than 36mm (such as 40mm) are used, the spacing between the top support steel pipes must be increased simultaneously (≤0.5m) and the local pressure of the channel steel must be verified.

[0018] The temporary steel support frame for the construction of a large-section underpinning beam of the present invention comprises a buckle scaffolding main body, a prop reinforcement system, and a top load-bearing unit.

[0019] Please refer to Figure 1 and Figure 2The main body of the said disc-type scaffolding: double rows of disc-type frames are set up on both sides of the supporting beam, wherein the horizontal spacing of the double rows is 600mm (one row on each side of the beam, 200mm away from the edge of the beam); the vertical spacing of the vertical poles 1 is 1200mm, and the step distance is 1.5m (high load conditions need to be increased to 1.0m); the adjustable height U-shaped support 6 of the support frame extends 600mm out of the top horizontal pole, and the exposed length of the screw rod is 300mm, and the adjustable support is inserted into the vertical pole for a length of 150mm; the sweeping rod 3 is 500mm from the ground; the bottom of the vertical pole adopts an adjustable base 5, the exposed length of the adjustable base screw rod is 200mm, the screw rod 16 has a diameter of 36mm, and the insertion length of the vertical pole is 150mm; the horizontal pole 2, longitudinal and transverse diagonal poles 4 are fully distributed to ensure the stiffness of the node. The connection method between the vertical pole and the horizontal pole: "The vertical pole 1 is welded with a connecting plate 7 every 500mm, and the horizontal pole end fastener head 8 is inserted into the corresponding socket of the connecting plate 7 and is fixed vertically through the fastener pin 9." Connection method between vertical pole and diagonal pole: "Special socket for diagonal pole is reserved on vertical pole connection plate 7, and end fastener head 8 of diagonal pole is inserted and fixed vertically through fastener joint pin 9"; The guy support reinforcement system: the guy support 10 is arranged according to the principle of "two spans and one setting" (i.e. the horizontal spacing is 2×1200mm=2400mm), the guy support 10 and the plate-locked vertical pole 1 are double-locked 14 by right-angle fasteners + rotary fasteners, the horizontal rod 2 and the horizontal steel pipe 11 are connected by right-angle fasteners + rotary fasteners 14, the horizontal steel pipe 11 and the guy support 10 are connected by right-angle fasteners + rotary fasteners 14, and the inclination angle of the diagonal brace is strictly controlled at 50°-60° to optimize the anti-lateral displacement efficiency. The end of the guy support should be connected to ≤200mm below the vertical pole node plate (horizontal pole intersection) to avoid the cantilever effect. The ground anchor point should be reinforced with a concrete pad. The horizontal projection length of the guy support is ≤2.5 times the vertical distance of the vertical pole (when the vertical distance is 1.2m, the projection length is ≤3.0m); The top load-bearing unit: The top of the buckle frame adopts an adjustable height U-shaped bracket 6, and the channel steel 12 is placed on the U-shaped bracket 6 to support the upper row of steel bars. The top support steel pipe 13 is used to support the channel steel 12 in the beam, with a spacing of 1200mm.

[0020] Material requirements for the construction of the temporary steel support frame for the large-section underpinning beam construction of the present invention: 1): Buckle pole: Made of Q355B hot-rolled seamless steel pipe, outer diameter 60mm, wall thickness 3.2mm, hot-dip galvanized (zinc layer thickness ≥ 80μm); 2): Horizontal rod: Made of Q235B steel pipe, outer diameter 48mm, wall thickness 2.75mm; 3): Sweeping rod: Made of Q235B steel pipe, outer diameter 48mm, wall thickness 2.75mm; 4): Longitudinal and transverse diagonal bars: Made of Q235B galvanized steel pipe with an outer diameter of 48mm and a wall thickness of 2.75mm; 5): Adjustable base: Manufacturer's standard Φ60×3.2mm buckle rack base; 6): Adjustable height U-shaped support: Made of Q355B steel, base plate size 150mm×150mm×8mm, adjusting screw (M36×6) made of 45# steel, adjustment range 0-500mm, bolt torque ≥40N·m; 7): Connecting plate: Made of Q355B steel, thickness ≥8mm, allowable deviation ±0.5mm, plate diameter ≥200mm, when welded to the vertical pole, effective weld height ≥3.5mm, 8 wedge-shaped sockets evenly distributed on the plate; 8): Rod end fastener head: Made of Q355B steel, hot-dip galvanized surface, the contact area between the fastener and the outer surface of the vertical pole steel pipe is ≥500mm², the size of the socket is consistent with the outer surface of the pin, and the edge of the hole needs to be chamfered (R ≥ 1mm); 9): Buckle joint pin: material not less than ZG 230-450 (yield strength ≥230MPa, tensile strength ≥450MPa), thickness ≥8mm, length customized according to the thickness of the node disk, ensure that it fits completely with the inner surface of the buckle joint after insertion; 10): Guy prop: Use Q355B hot-dip galvanized steel pipe with outer diameter Φ48mm and wall thickness 3.0mm (suitable for conventional loads) or Q355B hot-dip galvanized steel pipe with outer diameter Φ60mm and wall thickness 3.5mm (suitable for high load or large span conditions). Guy props are selected according to the working conditions to optimize material costs; 11): Horizontal steel pipe: same as the castor support; 12): Channel steel: Q355B grade hot rolled channel steel, section model 20a (height 200mm, leg width 73mm, waist thickness 7mm), surface hot dip galvanized; 13): Top support steel pipe: Q235B galvanized steel pipe with outer diameter Φ48mm and wall thickness 3.5mm; 14): Right angle fastener, rotating fastener double locking: ZG 230-450 cast steel; 15): Adjusting nut: Q235B carbon structural steel (in accordance with GB / T 700 Carbon Structural Steel); 16): Screw: Q235B carbon steel, matching the nut material; 17): Bottom plate: Q235B hot rolled steel plate (GB / T 700); 18): Support beam straight threaded steel bar: HRB400E, diameter 36mm; 19): Support beam stirrups: HRB400E, diameter 14mm, spacing 100mm.

[0021] Example 2 The construction process of the temporary steel support frame for the large-section underpinning beam construction of the present invention is as follows: (1) Construction preparation stage Be familiar with the construction drawings and patented technical solutions, and clearly define parameters such as the cross-sectional dimensions, span, and reinforcement specifications of the underpinning beam. Prepare a specific construction plan, perform force calculations on the truss frame, and determine key parameters such as pole spacing, pitch, and guying arrangement. Organize construction technical briefings, clarifying key operational points and safety and quality standards for each process. Check the specifications, galvanizing quality, and connector integrity of the truss frame poles, horizontal bars, guying steel pipes, and channel steel. Classify and stack materials, labeling specifications and locations for ease of use during construction. Clean the construction site, level the ground, and pour a 100mm thick C20 concrete cushion as the guying anchor foundation. Measure and lay out the lines, marking the truss frame pole positioning points based on the axial position of the underpinning beam to ensure the horizontal and vertical spacing of the double-row frames.

[0022] (2) Erection of scaffolding Position and lay out according to the designed spacing, install the adjustable base and level it; erect vertical poles, horizontal poles and longitudinal / transverse diagonal poles layer by layer, ensuring that the verticality deviation of the vertical poles is ≤1 / 500 and the pitch of the horizontal poles is ≤1.5m (increased to 1.0m for high loads); set an adjustable height U-shaped support on the top floor and install a sweeping pole.

[0023] (3) Installation of the towing system The guy prop is arranged according to the "two spans and one setting" principle (horizontal spacing of 2400mm), and the inclination angle of the guy prop is strictly controlled at 50°-60°; the end of the guy prop is double-locked at ≤200mm below the vertical pole node plate by a right-angle fastener + a rotating fastener, and the other end is anchored to the concrete cushion layer; the guy prop is connected to the horizontal steel pipe with double fasteners to ensure that the horizontal projection length is ≤3.0m (when the vertical distance between the vertical poles is 1.2m).

[0024] (4) Installation of top load-bearing unit Install an adjustable height U-shaped support on the top horizontal bar of the buckle frame. The length of the U-shaped support extending from the top horizontal bar is ≤650mm, the exposed length of the screw rod is ≤400mm, and the length inserted into the vertical bar is ≥150mm. Place Q355B hot-rolled channel steel (model 20a) on the U-shaped support, and the axis of the channel steel is perpendicular to the axis of the supporting beam. In the middle of the supporting beam, set top support steel pipes at intervals of 1200mm. The lower end of the top support steel pipe is supported on the bottom horizontal bar of the buckle frame, and the upper end is pressed against the bottom surface of the channel steel to form a multi-point support system.

[0025] (5) Test and acceptance Check whether the connections of the various components of the buckle frame are firm, whether all the pins are inserted and locked, and whether the tightening torque of the fasteners is ≥40Nm; measure the verticality, elevation, spacing and other parameters of the frame to ensure they meet the design requirements; conduct a load test, load at 1.2 times the construction load (steel deadweight + construction personnel load), observe the deformation of the frame, and the settlement is ≤5mm, with no obvious tilt or node failure.

[0026] (6) Steel bar binding Mark the top row of reinforcement lines on the top surface of the channel steel and draw ink lines based on the designed spacing to ensure accurate reinforcement placement. Tie the underpinning beam reinforcement in layers: first install the first row of top reinforcement, then stirrups, then install the reinforcement clamps and tie the reinforcement, then install the first row of bottom reinforcement, then the second row of bottom reinforcement, then the third row of bottom reinforcement, then the reinforcement clamps, and finally the second row of top reinforcement. Avoid reinforcement joints in the mid-span 1 / 3 of the underpinning beam. Before installing the beam side formwork, check the positional relationship between the reinforcement and the support frame to ensure the reinforcement skeleton is stable and free of offset or sagging.

[0027] (7) Removal of the support frame Follow the principle of "build first and dismantle later, build later and dismantle first", first dismantle the top channel steel and top supporting steel pipe, then dismantle the U-shaped support; dismantle the horizontal rods, diagonal rods, and vertical rods layer by layer, and finally dismantle the adjustable base; during the dismantling process, it is strictly forbidden to work simultaneously above and below, the components should be stacked in categories, and throwing is prohibited to ensure the safety of dismantling.

[0028] Construction control measures for the temporary steel support frame for the large-section underpinning beam construction of the present invention: (1) Control of the structure of the buckle frame The vertical bar connection plates are spaced 500mm apart. Horizontal bars connect to the connection plates via bar-end fasteners. The pins must penetrate vertically and be locked, ensuring a shear bearing capacity of ≥10kN (in accordance with GB / T 29903, "Disc-type Steel Tubular Support Components"). Vertical spacing of vertical bars is 1200mm, with double rows spaced 600mm apart horizontally, and 200mm from the beam edge, creating a symmetrical support system and enhancing the lateral stability of the frame. The standard spacing is 1.5m, increasing to 1.0m for high-load conditions (e.g., main bars with a diameter of 36mm). Sweeping bars are positioned 500mm from the ground to ensure vertical rigidity and prevent bottom sway. All longitudinal and transverse diagonal bars are installed, forming a stable triangular structure with the vertical and horizontal bars. The diagonal bars maintain an angle of 45°-60° with the horizontal, with a 50°-60° angle preferred to optimize lateral displacement resistance. The diagonal bar connection nodes are 100% covered, with no missing or defective bars.

[0029] (2) Control of the structure of the towing system The guy props are arranged according to the "two spans and one setting" (2400mm spacing), with the horizontal projection length ≤ 2.5 times the vertical distance of the vertical poles (3.0m). The connection point between the guy prop and the frame is within 200mm below the node plate to avoid cantilever stress; double locking with right-angle fasteners + rotating fasteners is used, with the number of fasteners at each connection point ≥ 2 to ensure reliable connection between the guy prop and the frame, and the pull-out force ≥ 8kN.

[0030] The inclination angle of the guy prop is strictly controlled within 50°-60°, and the deviation is ≤±2° when measured on-site with an angle ruler; the ground anchor point adopts C20 concrete cushion layer (thickness ≥100mm).

[0031] (3) Top load-bearing unit installation requirements The channel steel is placed in the center of the U-shaped support, with the same length extending at both ends. The flange of the channel steel faces the direction of force, and the height is adjusted by the U-shaped support so that the elevation of the top surface of the channel steel meets the requirements of steel bar positioning, with an error of ≤±3mm. The verticality deviation of the top support steel pipe is ≤1 / 200, and the contact surface with the channel steel needs to be polished flat, with a gap of ≤1mm. The spacing between the top support steel pipes in the beam is 1200mm, and they are set perpendicular to the channel steel. Adjustable supports are set at both ends. The upper end presses against the web of the channel steel, and the lower end is supported at the node of the horizontal rod of the buckle frame, forming a "U-shaped support + channel steel + top support steel pipe" three-point force system to ensure uniform transmission of the load of the upper row of steel bars.

[0032] (4) Material and node quality control The galvanized layer thickness of the buckle uprights and the steel pipes for the castanets must be ≥80μm, with no surface rust or cracks. After the fasteners are locked, 10% of them should be randomly inspected and re-tightened to ensure that there is no looseness. The center distance between rotating fasteners should be ≤150mm.

[0033] (5) Deformation monitoring and emergency measures During the construction process, the settlement and lateral displacement of the frame are monitored every 2 hours. When the cumulative settlement exceeds the limit, the operation is immediately suspended and reinforcement is carried out. In case of strong winds (≥ level 6) or heavy rain, temporary guy ropes are required, and the density of the guy ropes is increased to "one per span".

[0034] This invention possesses substantial features and significant technological advancements. The temporary steel support frame for large-section replacement beams utilizes a double-row, fully-installed, interlocking scaffolding system. Two-span, one-strap bracing enhances frame stability. A combined U-shaped support and channel steel structure supports the upper row of rebar, while additional steel pipe top-support channels are added within the beam to create a multi-point load-bearing system. Conventional steel pipe scaffolding full-length support systems require significantly reduced vertical column spacing (≤0.6m) to meet the load requirements of large-section replacement beams, resulting in increased material usage and limited construction space. However, the present invention utilizes a double-row, interlocking scaffolding composite bracing system, increasing the vertical column spacing to 1200mm. This reduces material usage under the same load, while the two-span, one-strap bracing (with a horizontal spacing of 2400mm) enhances lateral resistance and overall stability. While conventional steel support systems require complex welding or high-strength bolt connections, the present invention utilizes modular interlocking scaffolding and standardized connection nodes (bolt-type fixings), improving erection efficiency, shortening the construction period, and eliminating the need for specialized welders, reducing labor costs. While the material cost of the steel support system is high, the use of Q355B steel pipes in the truss brackets is more affordable and, combined with their reusability, reduces overall costs. Furthermore, the top channel steel and U-shaped brackets replace traditional wooden beams, reducing temporary material waste and auxiliary costs. Traditional steel joints require full nondestructive testing, resulting in weld defect rates as high as 8%. This new design, through latch connections and double-bolt fasteners, eliminates weld quality risks and reduces the risk of joint failure. Furthermore, the channel steel and top support steel pipes form a multi-point load-bearing system, limiting steel bar settlement to ≤5mm and avoiding the localized deformation associated with traditional supports. The adjustable base (adjustable range: 0-500mm) and U-shaped brackets (adjustable height: 0-500mm) allow the support frame height to precisely match the cross-section of the underpinning beam (1.8-3.5m), offering far greater adaptability than traditional fixed supports. For extremely long spans (≤32m), the truss brackets are constructed in sections (spacing ≤16m) to avoid excessive deflection associated with traditional steel sections, enhancing construction flexibility.

[0035] The temporary steel support frame for the construction of large-section replacement beams of the present invention has been used in the Guangzhou Convention and Exhibition Center project, with remarkable effects. It is simple to construct, easy to operate, and firmly installed. It has sufficient strength, rigidity, and stability, a wide range of applications, is easy to master, and is easy to promote and use. It has been unanimously recognized by the supervision unit and the construction unit, and has been welcomed by the operating personnel, achieving good economic benefits and social impact.

[0036] The above embodiments are intended to illustrate the present invention only and are not intended to limit the present invention. Persons skilled in the art may make various modifications or variations without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions are intended to fall within the scope of the present invention and are defined by the claims.

Claims

1. A temporary steel support frame for the construction of large-section underpinning beams, comprising a main body of a scaffolding with a sling, a reinforcement system, and a top load-bearing unit, characterized in that: The main body of the buckle scaffolding comprises: a row of buckle frames on each side of the supporting beam, and a row of buckle frames is 200mm away from the beam edge; a plurality of buckle frame vertical poles (1) are longitudinally spaced 1200mm apart and have a step distance of 1.5m; a U-shaped support (6) with an adjustable height extending 600mm from the top horizontal pole of the buckle frame, and a screw rod exposed length of 300mm, and an adjustable support inserted into the vertical pole length of 150mm; a sweeping rod (3) 500mm from the ground; an adjustable base (5) is used at the bottom of the vertical pole, and the screw rod of the adjustable base is exposed length of 200mm, and a plurality of screw rods (16) are 36 in diameter. mm, the length of the inserted vertical rod is 150mm; the horizontal rod (2), longitudinal and transverse diagonal rods (4) are fully distributed to ensure the node stiffness; the connection method of the vertical rod and the horizontal rod is: "the vertical rod (1) is welded with a connecting plate (7) every 500mm, and the horizontal rod end fastener head (8) is inserted into the corresponding socket of the connecting plate (7) and fixed vertically through the fastener pin (9); the connection method of the vertical rod and the diagonal rod is: "the vertical rod connecting plate (7) is reserved with a special socket for the diagonal rod, and the end fastener head (8) of the diagonal rod is inserted and fixed vertically through the fastener pin (9)"; The said guy support reinforcement system comprises: the guy support (10) is arranged according to the principle of "two spans and one set", so that the horizontal spacing is set to 2×1200mm, the guy support (10) and the plate buckle vertical pole (1) are double locked (14) by right-angle fasteners and rotating fasteners, the horizontal pole (2) and the horizontal steel pipe (11) are double locked (14) by right-angle fasteners and rotating fasteners, the horizontal steel pipe (11) and the guy support (10) are double locked (14) by right-angle fasteners and rotating fasteners, the end of the guy support is connected to the vertical pole node plate, and the ground anchor point is poured with a concrete cushion layer for reinforcement; The top load-bearing unit: the top of the buckle frame adopts an adjustable height U-shaped support (6), and the channel steel (12) is placed on the U-shaped support (6) to support the upper row of steel bars. The top support steel pipe (13) is used in the beam to support the channel steel (12), and the spacing is set to 1200mm.

2. The temporary steel support frame for the construction of a large-section underpinning beam according to claim 1 is characterized in that: The inclination angle of the castor is strictly controlled at 50°-60°.

3. The temporary steel support frame for the construction of a large-section underpinning beam according to claim 1 is characterized in that: The horizontal projection length of the guy support is ≤2.5 times the vertical distance of the vertical pole. When the vertical distance is 1.2m, the projection length is ≤3.0m.

Images