Cast-in-situ beam assembly type support system

Abstract

The utility model relates to a cast-in-place beam assembly type support system belongs to bridge construction technical field. The cast-in-place beam assembly type support system, include: assembly type support frame, sliding type box beam form and prefabricated base, sliding type box beam form sliding connection in the top of assembly type support frame, prefabricated base includes concrete base, concrete base is inserted in the bottom of assembly type support frame, the inside embedded installation of concrete base has reinforced skeleton, reinforced skeleton's surface is connected with threaded column fixedly, prefabricated base is inserted in assembly type support frame bottom through concrete base directly, inside reinforced skeleton fixed connection threaded column, threaded column penetrates assembly type support frame and is engaged with lock nut thread, realizes second grade dismounting and rigid connection. The design thoroughly exempts from on -the -spot pouring and demolishing time -consuming, shortens the construction period significantly, and supports the non - destructive recovery recycling.

Description

Technical Field

[0001] This utility model relates to the field of bridge construction technology, and in particular to a cast-in-place prefabricated support system for beams. Background Technology

[0002] In the construction of continuous cast-in-place bridges, scaffolding support systems are widely used, but their erection is cumbersome and time-consuming. To improve efficiency, the steel pipe column support structure of Bailey bridge crossbeams has been developed. Its bottom requires on-site pouring of concrete base. At the same time, cast-in-place beams generally use steel mold structures for concrete molding.

[0003] The concrete base at the bottom of the support structure needs to be poured and dismantled on-site, a time-consuming and labor-intensive process that cannot be recycled. This has become the most critical bottleneck restricting the improvement of construction efficiency and significantly extending the construction period. Utility Model Content

[0004] Therefore, it is necessary to provide a cast-in-place beam prefabricated support system to address the problem that the construction efficiency of existing non-recyclable concrete bases is low, which seriously prolongs the construction period of continuous cast-in-place bridges.

[0005] A cast-in-place beam prefabricated support system includes: a prefabricated support frame, a sliding box girder formwork, and a prefabricated base, wherein the sliding box girder formwork is slidably connected to the top of the prefabricated support frame.

[0006] In one embodiment, the prefabricated base includes a concrete base inserted into the bottom of the prefabricated support frame. A steel reinforcement skeleton is embedded inside the concrete base. A threaded post is fixedly connected to the surface of the steel reinforcement skeleton. The top of the threaded post passes through the outside of the steel reinforcement skeleton and the prefabricated support frame in sequence. A locking nut that contacts the prefabricated support frame is threaded onto the surface of the threaded post.

[0007] In one embodiment, the vertical cross-sectional shape of the concrete base is convex, and the hardened strength grade of the concrete base is not lower than C60.

[0008] In one embodiment, a positioning column is fixedly connected to the top of the concrete base, and the top of the positioning column extends into the interior of the prefabricated support frame.

[0009] In one embodiment, the top of the positioning post is beveled, and the highest point of the positioning post and the threaded post are located on the same horizontal plane.

[0010] In one embodiment, the surface of the steel reinforcement frame is fixedly connected with lifting lugs, the top of which extends through to the concrete base.

[0011] In one embodiment, the number of lifting lugs is four, and the four lifting lugs are arranged in a ring around the positioning post.

[0012] In one embodiment, the bottom of the concrete base is provided with a resistance-increasing groove, which is in the shape of a grid.

[0013] In one embodiment, the vertical cross-sectional shape of the resistance-increasing groove is an isosceles trapezoid, and the resistance-increasing groove is located directly below the reinforcing steel frame.

[0014] Beneficial effects 1. In the aforementioned prefabricated support system for cast-in-place beams, the precast base is directly inserted into the bottom of the prefabricated support frame via a concrete base. The internal steel reinforcement skeleton is fixedly connected to threaded columns, which penetrate the prefabricated support frame and engage with locking nuts, achieving disassembly and rigid connection within seconds. This design completely eliminates the time-consuming process of on-site casting and dismantling, significantly shortens the construction cycle, and supports non-destructive recycling.

[0015] 2. The precast concrete base is factory-prefabricated into a C60 high-strength matrix. The bottom friction-enhancing groove is deeply embedded in the foundation to strengthen anti-slip stability. A ring of lifting lugs runs through the base, ensuring safety during lifting and transportation, as well as reliability for repeated use. This modular structure enables efficient cyclic installation, overcoming the bottleneck of traditional bases being non-recyclable. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram showing the connection between a portion of the assembled support frame and the prefabricated base in this utility model; Figure 3 This is a partial cross-sectional view of the assembled support frame and the prefabricated base in this utility model; Figure 4 This is a partial structural diagram of the prefabricated base in this utility model; Figure 5 This is an exploded view of the concrete base and positioning column in this utility model.

[0018] Figure label: 100. Prefabricated support frame; 200. Sliding box girder formwork; 300. Precast base; 310. Concrete base; 311. Resistance groove; 320. Reinforcing steel cage; 330. Threaded column; 340. Locking nut; 350. Positioning column; 360. Lifting lug. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0020] The following is combined with Figure 1 - Figure 5 This invention describes the prefabricated support system for cast-in-place beams.

[0021] In one embodiment, a cast-in-place beam prefabricated support system includes: a prefabricated support frame 100, a sliding box girder template 200, and a prefabricated base 300, wherein the sliding box girder template 200 is slidably connected to the top of the prefabricated support frame 100.

[0022] like Figure 1 , Figure 2 and Figure 3 As shown, the prefabricated support frame 100 structure mainly consists of: steel pipe columns, cross braces, quick-release clamps, detachment blocks, crossbeams, and Bailey bridges. The steel pipe columns are fixedly connected to flanges, which simultaneously connect to threaded posts 330 and positioning posts 350 as described below. The steel pipe column structure provides stable support for the entire support structure. The cross brace structure ensures stability between the steel columns. The quick-release clamp structure ensures a stable connection between the cross braces and the steel pipe columns. The detachment block structure allows for quick separation of the crossbeams, Bailey bridges, and the beam body. A Bailey bridge structure is installed on top of the crossbeams to support the upper cast-in-place box girder.

[0023] like Figure 1 As shown, the sliding box girder formwork 200 mainly consists of a track-type outer formwork and a telescopic inner formwork. The track-type outer formwork mainly consists of: outer formwork, track, pulleys, support frame, and winch. The outer formwork rests on the track via pulleys and can slide along the track. The pulley structure has a built-in locking device. After the formwork is installed in place, the support frame structure supports the outer formwork to prevent it from sliding on the track. The winch mechanism provides power for the sliding of the formwork. The telescopic inner formwork mainly consists of: formwork, support frame, and hydraulic telescopic rod. The formwork structure is connected to the support frame via the hydraulic telescopic rod, and the extension and retraction of the hydraulic telescopic rod realizes the support and retraction of the inner formwork.

[0024] like Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the concrete base 310 of the precast base 300 adopts a convex vertical cross-section design, with an embedded steel reinforcement skeleton 320 and prefabricated into a high-strength matrix of no less than C60. It is directly inserted into the bottom of the prefabricated support frame 100, completely eliminating the time-consuming on-site pouring and curing. The threaded column 330 fixed to the surface of the steel reinforcement skeleton 320 extends to the outside of the prefabricated support frame 100, achieving rigid connection and second-level disassembly through threaded engagement with the locking nut 340. The top of the positioning column 350 of the concrete base 310 is machined at an angle, and is at the same level as the threaded column 330, ensuring accurate insertion and positioning of the steel pipe column flange. Four lifting lugs 360 distributed in a ring on the surface of the steel reinforcement skeleton 320 penetrate the concrete base 310, ensuring the safety of the lifting and transportation process and the reliability of repeated use. A grid-like friction-increasing groove 311 is opened at the bottom of the concrete base 310, and its isosceles trapezoidal vertical cross-section is deeply embedded in the foundation, greatly enhancing the anti-slip stability.

[0025] Working principle: The precast base 300, with its factory-prefabricated concrete base 310 and built-in steel reinforcement frame 320, completely replaces the traditional on-site cast-in-place concrete base. During construction, the precast base 300 is directly hoisted to the leveled site, eliminating the need for formwork, pouring, and curing. During dismantling, simply loosening the locking nut 340 allows for damage-free recycling, and it can be transported to the next span for reuse via the lifting lug 360. This design significantly shortens the construction time for a single span base. Thanks to the C60 high-strength concrete base 310 and modular connection structure, it allows for multiple reuses, overcoming the key bottlenecks of traditional cast-in-place concrete bases, which are non-recyclable and have lengthy construction periods.

[0026] The specific construction process of this cast-in-place beam prefabricated support system is as follows: 1. Installation of Precast Base 300: Before the installation begins, the component structures are hoisted to the installation area. Then, the installation area of ​​the precast base 300 is treated. For areas with good geological conditions, simple leveling and compaction are sufficient. For areas with poor geological conditions, the base layer can be treated by dynamic compaction, grouting hardening, or laying steel plates. After the base layer is treated, the precast base 300 is hoisted. The hoisting of the precast base 300 is carried out slowly to avoid collisions. After the precast base 300 is in place, it needs to be leveled to ensure that its inclination is less than 1000 / H and that the precast base 300 will not shake during operation. After the precast base 300 is hoisted, the precast locking nuts 340 on the upper part are unscrewed to prepare for the installation of the superstructure. II. Installation of Steel Pipe Columns and Cross Bracing: The steel pipe column structure is connected to the precast base 300 via a flange at the bottom. During construction, the steel pipe column is first lifted by a truck crane to a position directly above the precast base 300. Then, guided by a traction rope and workers, the flange is inserted into the threaded column 330 of the precast base 300. Subsequently, the verticality of the steel pipe column is adjusted using a total station and inclinometer to ensure that the verticality does not exceed 1000 / H. After the verticality meets the requirements, the locking nuts 340 are tightened in two stages, and the final tightening torque of the locking nuts 340 is checked. After the torque meets the requirements, the above construction steps are repeated to install the remaining steel pipe columns. After the steel pipe column construction is completed, the steel clamps of the cross bracing structure are installed and fixed with bolts. Then, the horizontal supports of the cross bracing beam are connected to the steel clamps with bolts. Finally, the cross diagonal bracing is installed in place. III. Installation of Crossbeams and Bailey Bridges: After the steel pipe columns and cross braces are installed, the slack beam structure is bolted to the top of the steel pipe columns. The slack beams are then leveled to ensure that the height difference between adjacent slack beam tops is no more than 2mm. After leveling, the height of the slack beams is locked with locking bolts. The crossbeam structure is then hoisted using a truck crane. After hoisting, the crossbeams are leveled again, and then bolted together with the slack beams. After the crossbeam structure is installed, the Bailey bridges are installed, secured to the crossbeams with U-bolts. IV. Track-mounted external formwork hoisting: When hoisting the track-mounted external formwork structure, first press the track of the external formwork onto the box girder support platform using the pressure beam fasteners. After the track is fixed, install the bottom formwork of the box girder at the beam position, and then carry out the hoisting construction of the external formwork. When hoisting the external formwork, first lift the formwork with a truck crane, and then, under the guidance of the workers, align the steel wheels of the formwork with the track and lower it. After the external formwork is placed on the rail, adjust the position of the formwork. After the adjustment is completed, use the external support legs for support. After the reinforcement is tied, start the hydraulic adjustment device to install the external formwork and the bottom formwork together, and make precise adjustments to the position of the external formwork without leaving gaps. V. Reinforcement Binding: Before binding the reinforcement, clean the precast box girder platform to ensure it is clean. After cleaning, apply a release agent evenly. Bind the bottom slab reinforcement and web reinforcement on the precast box girder platform. During the binding process, the reinforcement must be accurately positioned, and the welded joints must be secure. All other interlacing points must be firmly secured with tie wire. After binding, check the spacing of the reinforcement and the binding of the tie wires. Only after passing the inspection can the next step be performed. After binding, accurately install the outer protective corrugated pipe of the prestressed steel cable. After the corrugated pipe is installed, install the spiral reinforcement, anchor plates, and ventilation holes. VI. Installation of Telescopic Inner Mold: Before installation, the inner mold should be ground and cleaned. After grinding and cleaning, a release agent should be applied evenly. Then, the inner mold should be hoisted and installed in sections. During installation, the joints between the sections should be sealed with double-sided tape. After sealing, the sections should be connected into a whole using connecting bolts. After the inner mold is assembled, the hydraulic device should be activated to support the inner mold outward to the designated position. VII. Concrete Pouring: Before pouring, the slump of the concrete should be tested by testing personnel. The slump should be controlled between 160mm and 200mm. Pouring can proceed after the test is passed. A gantry crane with a hopper is used to pour the precast box girder. The pouring sequence is bottom slab, web, and top slab. During the web pouring process, horizontal layer pouring is required, with each layer thickness controlled at 30cm. The concrete pouring should be completed continuously in one go. During the pouring process, an attached high-frequency vibrator is used as the main vibrator, supplemented by an immersion vibrator. The high-frequency vibrators are arranged in two rows in a quincunx pattern, vibrating intermittently. Each vibration is controlled at 10-20 seconds, with a 5-second interval before vibrating again. Each layer of concrete is vibrated 3-4 times. For the prestressed tendon anchorage area and other areas with dense reinforcement, a 30-type immersion vibrator is used to vibrate while pouring the concrete. After the concrete is poured, the surface is finished and troweled three times to prevent shrinkage cracks. After finishing, the top of the beam is roughened. 8. Formwork Removal and Cyclic Construction: The box girders are constructed continuously and alternately on site. During construction, after the first span of the box girder is poured and cured, the formwork is pulled out to pour the second span. During the pouring and curing of the second span, the support frame of the first span is removed and installed in the third span. After the support is installed, the second span of the box girder reaches the required strength. The outer and inner formwork is then removed to support the third span of the box girder. The above construction steps are repeated continuously for pouring construction.

[0027] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A cast-in-place prefabricated support system for beams, characterized in that, include: The prefabricated support frame (100) and the sliding box girder template (200) are slidably connected to the top of the prefabricated support frame (100); A precast base (300) includes a concrete base (310), which is inserted into the bottom of an assembled support frame (100). A steel reinforcement frame (320) is embedded inside the concrete base (310). A threaded post (330) is fixedly connected to the surface of the steel reinforcement frame (320). The top of the threaded post (330) passes through the steel reinforcement frame (320) and the outside of the assembled support frame (100) in sequence. A locking nut (340) that contacts the assembled support frame (100) is threaded onto the surface of the threaded post (330).

2. The cast-in-place beam prefabricated support system according to claim 1, characterized in that, The vertical cross-sectional shape of the concrete base (310) is convex, and the hardened strength grade of the concrete base (310) is not lower than C60.

3. The cast-in-place beam prefabricated support system according to claim 1, characterized in that, The top of the concrete base (310) is fixedly connected to a positioning column (350), the top of which extends into the interior of the prefabricated support frame (100).

4. The cast-in-place beam prefabricated support system according to claim 3, characterized in that, The top of the positioning post (350) is beveled, and the highest point of the positioning post (350) and the threaded post (330) are set on the same horizontal plane.

5. The cast-in-place beam prefabricated support system according to claim 4, characterized in that, The surface of the steel reinforcement frame (320) is fixedly connected with a lifting lug (360), the top of which extends through to the concrete base (310).

6. The cast-in-place beam prefabricated support system according to claim 5, characterized in that, The number of the lifting lugs (360) is four, and the four lifting lugs (360) are arranged in a ring around the positioning post (350).

7. The cast-in-place beam prefabricated support system according to claim 1, characterized in that, The bottom of the concrete base (310) is provided with a resistance-increasing groove (311), and the resistance-increasing groove (311) is in the shape of a grid.

8. The cast-in-place beam prefabricated support system according to claim 7, characterized in that, The vertical cross-sectional shape of the resistance-increasing groove (311) is an isosceles trapezoid, and the resistance-increasing groove (311) is located directly below the steel reinforcement cage (320).

Images