Wet joint structure with bottom mold for cast-in-place layer of small box girder bridge deck

Abstract

The utility model relates to the field of bridge engineering construction technology, and specifically discloses a bottom mould wet joint structure of small box girder bridge deck cast-in-place layer. The structure comprises two box girders arranged side by side at intervals, a bearing assembly installed at the bottom of the gap between the two box girders and a fixing assembly blocked at the end. The bottom mould of the bearing assembly is self-supporting erected through the sliding connection of the sliding blocks on both sides and the sliding grooves of the box girder side walls. The fixing assembly is connected with the internal screw pieces embedded in the end faces of the box girder and the bottom mould through the partition plate and the screw, forming a rigid whole. The utility model realizes the bracket-free rapid installation and position fine adjustment of the bottom mould through the cooperation of the sliding grooves and the sliding blocks, solves the problems of slurry leakage and unstable connection through the end bolt fastening, and effectively improves the wet joint construction efficiency and the concrete pouring quality.

Description

Technical Field

[0001] This utility model relates to the field of bridge engineering construction technology, and in particular to a wet joint structure with bottom formwork for cast-in-place layer of small box girder bridge deck. Background Technology

[0002] In modern highway and municipal bridge construction, prefabricated small box girders have been widely used due to their good load-bearing performance, beautiful appearance, and fast construction speed. During the erection of small box girders, in order to form an integral bridge deck structure, a certain width gap is usually left between the flanges of two adjacent box girders. This gap needs to be connected by pouring concrete on site, and this connection is called a wet joint.

[0003] The key to wet joint construction lies in the installation and support of the bottom formwork, the quality of which directly affects the integrity and durability of the bridge structure. However, under the existing construction technology system, the erection of the bottom formwork for wet joints faces many difficulties. Traditional construction methods often rely on erecting full-span scaffolding or using bridge cranes to suspend the formwork for operation. The scaffolding method is greatly limited by the terrain under the bridge (such as crossing rivers or roads) and is costly. While the suspended formwork method avoids the need for scaffolding, it requires workers to perform complex installation of suspension rods and formwork fixing operations at high altitudes, which is not only inefficient but also poses extremely high safety risks for high-altitude operations.

[0004] Furthermore, existing bottom formwork structures typically lack effective positioning and connection mechanisms with the box girder sidewalls, often relying on temporary wooden formwork or steel plate supports, which suffers from poor stability. During concrete pouring, the bottom formwork is prone to sinking or shifting due to the concrete's own weight and vibration force, resulting in poor flatness at the bottom of the wet joint. Simultaneously, current technologies for sealing the ends of wet joints often employ simple filling methods, lacking rigid connection structures, making them highly susceptible to formwork slippage and grout leakage during pouring, severely impacting the quality and appearance of the concrete.

[0005] Therefore, this utility model proposes a wet joint structure with bottom formwork for the cast-in-place layer of the small box girder bridge deck to solve the shortcomings of the prior art. Utility Model Content

[0006] To overcome the above deficiencies, this utility model provides a wet joint structure with bottom formwork for the cast-in-place layer of small box girder bridge deck, aiming to improve the structural defects in the existing technology of small box girder wet joint construction, such as difficulty in bottom formwork support, high risk of high-altitude operation, and easy leakage of grout at the end sealing.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a wet joint structure with bottom formwork for cast-in-place layer of small box girder bridge deck, comprising: two box girders arranged side by side with intervals, wherein a wet joint gap is formed between the side walls of the box girders; and a load-bearing component installed at the bottom of the wet joint gap and a fixing component sealing the end of the wet joint gap.

[0008] The load-bearing component includes a bottom formwork located within the wet joint gap, and sliding blocks disposed on the side walls of the bottom formwork. The side wall of the box girder facing the wet joint gap has a groove along its length, and the sliding blocks are slidably engaged inside the groove, so that the bottom formwork is erected between the two box girders through the snap-fit ​​engagement between the sliding blocks and the groove.

[0009] Furthermore, the fixing assembly includes a partition plate that fits and covers the end opening of the wet joint gap, and screws for fastening the connection; a first connecting groove is provided on the end side wall of the box girder, a second connecting groove is provided on the end face of the bottom mold, and a through screw hole is provided on the surface of the partition plate; when the partition plate covers the end faces of the box girder and the bottom mold, the position of the screw hole corresponds to and communicates with the positions of the first connecting groove and the second connecting groove, respectively; the screw passes through the screw hole and is screwed into the internally threaded connectors pre-embedded in the first connecting groove and the second connecting groove, respectively, to fix the two box girders and the bottom mold into a rigid whole.

[0010] Preferably, the upper surface of the bottom mold is provided with a plurality of grooves, which are arranged at intervals along the width or length direction of the bottom mold to increase the contact area between the bottom mold and the cast-in-place concrete; the bottom mold is covered with reinforcing ribs, which extend along the length direction of the bottom mold to enhance the structural strength of the bottom mold.

[0011] Preferably, a number of reinforcing bars extend laterally from the upper side wall of the box girder, and the reinforcing bars are suspended above the load-bearing component; the reinforcing bars extending from two adjacent box girders are staggered or welded together in the space above the wet joint gap to form a skeleton structure for pouring concrete.

[0012] Preferably, the cross-sectional shape of the chute is dovetail, T-shaped, or trapezoidal, and the sliding block has a protruding structure adapted to the shape of the chute; the bottom mold is restricted from vertical displacement relative to the box girder by the sliding block being embedded in the chute.

[0013] Preferably, the first connecting groove is located on the side wall of the box girder end near the sliding groove, and the second connecting groove is located on the end face of the bottom mold near the sliding block; the length of the screw is greater than the thickness of the partition plate, and the screw is locked with the inside of the first connecting groove and the second connecting groove by means of thread engagement.

[0014] Preferably, the contour shape of the partition is adapted to cover the end sidewalls of the two box girders and the end face of the bottom formwork, forming a closed concrete pouring cavity end face; a sealing gasket or grout-stopping strip is provided between the contact surfaces of the partition and the box girders and the bottom formwork.

[0015] Preferably, the bottom mold is a precast concrete component, which is retained as a permanent template in the wet joint structure after pouring, and is integrated with the newly poured concrete.

[0016] Preferably, the cross-sectional shape of the groove is an inverted trapezoid or rectangle, and the depth of the groove is less than half the thickness of the bottom mold, and the reinforcing rib is located below the groove.

[0017] This utility model has the following beneficial effects: 1. This utility model solves the problem of low construction efficiency and high risk of high-altitude operation caused by the reliance on ground supports or complex hanging systems in the construction of wet joints by opening a sliding groove on the side wall of the box girder and setting sliding blocks on both sides of the bottom formwork. It achieves the technical effect of self-supporting installation of the bottom formwork without support. This structure not only simplifies the on-site construction process and significantly improves the installation efficiency, but also allows the bottom formwork to be adjusted horizontally along the direction of the sliding groove during the installation process, thereby effectively adapting to the construction errors in the spacing of the box girder erection.

[0018] 2. This utility model solves the problems of insecure sealing and fixing of traditional wet joint ends, easy formwork leakage and grouting, and loose connection between the bottom formwork and the box girder during construction by using a partition plate in the fixing component and screws to lock the internal threaded connectors embedded in the box girder and bottom formwork. It achieves the technical effect of rigidly connecting the left and right box girders and the middle bottom formwork at the end position as a single unit. This not only forms a closed and reliable concrete pouring cavity to prevent grout leakage, but also further enhances the bottom formwork's anti-settlement ability and overall stability during the pouring process. Attached Figure Description

[0019] Figure 1 This is a perspective view of the wet joint structure with bottom formwork of the cast-in-place layer of the small box girder bridge deck proposed in this utility model. Figure 2 This is a schematic diagram of the bottom plate of the cast-in-place layer of the small box girder bridge deck with wet joint structure with bottom formwork proposed in this utility model; Figure 3This is a schematic diagram of the sliding groove structure with bottom formwork wet joint of the cast-in-place layer of the small box girder bridge deck proposed in this utility model. Figure 4 This is a schematic diagram of the groove structure of the wet joint with bottom formwork in the cast-in-place layer of the small box girder bridge deck proposed in this utility model. Figure 5 This is a schematic diagram of the partition plate of the wet joint structure with bottom formwork for the cast-in-place layer of the small box girder bridge deck proposed in this utility model.

[0020] Legend: 1. Box girder; 2. Reinforcing steel; 3. Load-bearing components; 301. Bottom formwork; 302. Sliding block; 303. Slide groove; 304. Groove; 305. Reinforcing rib; 4. Fixing components; 401. Partition plate; 402. First connecting groove; 403. Second connecting groove; 404. Screw hole; 405. Screw. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Reference Figures 1-5 This utility model provides an embodiment of a small box girder bridge deck cast-in-place layer with a bottom formwork wet joint structure, including two box girders 1 arranged side by side at intervals, and a load-bearing component 3 and a fixing component 4 set between the two box girders 1. A wet joint gap is naturally formed between the side walls of the two box girders 1. The wet joint gap serves as a space for subsequent concrete pouring. The load-bearing component 3 is installed at the bottom of the wet joint gap to form a bottom support, and the fixing component 4 is sealed at the end of the wet joint gap to form an end face closure. Through the cooperation of the box girders 1, the load-bearing component 3 and the fixing component 4, a closed cavity for pouring concrete is constructed.

[0023] Specifically, the box girder 1, as the main load-bearing body, has a groove 303 along its length on the side wall facing the wet joint gap. The groove 303 extends longitudinally along the box girder 1 and penetrates the side wall surface of the box girder 1. The load-bearing component 3 mainly consists of a bottom mold 301 and sliding blocks 302 set on the side walls of the bottom mold 301. The bottom mold 301 has a long strip-shaped structure, and its width is adapted to the gap width between the two box girders 1. The bottom mold 301 establishes a sliding connection with the groove 303 on the side wall of the box girder 1 through the sliding blocks 302 on both sides.

[0024] In terms of structural details, the cross-sectional shape of the sliding block 302 is adapted to the cross-sectional shape of the groove 303, preferably adopting a dovetail, T-shaped, or trapezoidal structure. This shape fit allows the sliding block 302, after being embedded in the groove 303, to not only restrict the downward displacement of the bottom mold 301 in the vertical direction through geometric locking, achieving self-supporting suspension of the bottom mold 301, but also to allow the bottom mold 301 to slide and adjust along the length of the groove 303 during installation, so as to eliminate construction errors and align the installation position. As a precast concrete component, the bottom mold 301 is internally covered with reinforcing ribs 305 to strengthen... The reinforcing bars 305 extend along the length of the bottom mold 301 and are evenly distributed in the base of the bottom mold 301 to enhance the overall bending stiffness and structural strength of the bottom mold 301 and prevent breakage or excessive deformation during concrete pouring. At the same time, the upper surface of the bottom mold 301 is provided with several grooves 304, which are arranged at intervals along the width or length of the bottom mold 301. By increasing the roughness and surface area of ​​the upper surface of the bottom mold 301, the physical interlocking force between the bottom mold 301 and the subsequent cast-in-place concrete layer is improved, so that the bottom mold 301 can remain in the beam as a permanent structure, avoiding the cumbersome process of demolding later. The fixing component 4 includes a partition plate 401 with a suitable shape and several matching screws 405. The partition plate 401 has a shape that matches the contour of the end side wall of the box girder 1 and the contour of the end face of the bottom formwork 301. It is preferably an inverted trapezoidal or T-shaped plate structure to ensure that it can completely cover the opening area at the end of the wet joint gap. Several screw holes 404 penetrating the thickness direction of the plate are opened on the plate body of the partition plate 401. The positions of these screw holes 404 are not randomly distributed, but are precisely preset according to the specific position of the subsequent connection point. The partition plate 401 is fitted to the end face of the box girder 1 and the bottom formwork 301, and a sealing gasket or grout-stopping strip can be selectively sandwiched between the contact surfaces to further block the path of concrete grout leakage from the tiny gaps and play a role in sealing and preventing leakage.

[0025] Meanwhile, a first connecting groove 402 is provided on the end side wall of the box girder 1 near the sliding groove 303, and a second connecting groove 403 is provided on the end face of the bottom mold 301 near the sliding block 302. The first connecting groove 402 and the second connecting groove 403 are not simple pits; internal threaded sleeves or anchors are pre-embedded inside them. These pre-embedded parts provide reliable force points for the screw 405. When the partition plate 401 is in place, the screw holes 404 on the partition plate 401 are connected to the positions of the first connecting groove 402 on the box girder 1 and the second connecting groove 403 on the bottom mold 301. At this time, the screw 405 passes through the screw holes 404 on the partition plate 401 and is screwed into the pre-embedded parts inside the first connecting groove 402 and the second connecting groove 403 for locking. The length of the screw 405 is designed to be greater than the thickness of the partition plate 401 to ensure that its threaded part can penetrate into the pre-embedded part and generate sufficient gripping force and fastening force.

[0026] This end-sealing structure, which utilizes partition plate 401 in conjunction with multi-point bolt connections, forcibly connects the originally independent left box girder 1, right box girder 1, and the middle bottom formwork 301 into a rigid whole at the end position. This not only effectively seals the end face of the pouring cavity, preventing the lateral pressure during concrete pouring from causing formwork displacement or grout leakage, but also further enhances the anti-settlement ability and overall stability of the bottom formwork 301 during the pouring process by fastening the bottom formwork 301 to the two side box girder 1. As for the specific tools used to drive or operate these components, those skilled in the art can use various conventional methods such as electric wrenches and manual wrenches. The specific operation process is well-known in the field and will not be described in detail here. In a preferred embodiment, to increase the bonding force between the bottom formwork 301 and the cast-in-place concrete layer, the upper surface of the bottom formwork 301 is provided with several grooves 304, such as... Figure 1 and Figure 3 As shown, the grooves 304 are arranged at intervals along the width or length of the bottom mold 301, preferably with an inverted trapezoidal or rectangular cross-section. The depth of the grooves 304 is less than half the thickness of the bottom mold 301. Through this surface treatment, the bottom mold 301 not only provides a larger contact area for the newly poured concrete to adhere, but its inverted trapezoidal cross-section can also form a wedge-like mechanical interlocking structure, effectively preventing the concrete from peeling or delaminating from the bottom mold 301 after solidification, further ensuring the integrity and durability of the wet joint structure.

[0027] As another preferred embodiment, to enhance the load-bearing capacity and crack resistance of the bottom mold 301, please refer to... Figure 3The bottom mold 301 is internally covered with reinforcing ribs 305. The reinforcing ribs 305 are located below the groove 304 and extend along the stress direction of the bottom mold 301. The reinforcing ribs 305 can be made of threaded steel bars or high-strength steel wire mesh. Both ends can extend to the ends of the bottom mold 301 or even protrude to connect with the end fixing component 4 or other steel reinforcement structures. By placing reinforcing ribs 305 in the thin plate component of the bottom mold 301, the ability of the bottom mold 301 to bear the self-weight of the wet joint concrete and construction load is significantly improved, and the bottom mold 301 is prevented from brittle fracture during the pouring process.

[0028] As another preferred embodiment, in order to form a complete concrete casting skeleton, several steel bars 2 extend laterally from the upper part of the side wall of the box girder 1. These steel bars 2 are suspended in the space above the bearing component 3. The steel bars 2 extending from two adjacent box girders 1 are staggered or welded together in the space above the wet joint gap. By connecting the steel bars 2 extending from the left and right box girders 1 and cooperating with the bearing component 3 at the bottom, a stable three-dimensional steel mesh is constructed. After the concrete is poured and wrapped around the mesh, it can effectively transfer the shear force and bending moment between the box girders and realize the continuity of the bridge deck structure.

[0029] In another preferred embodiment, in order to ensure the sealing effect of the partition 401, the outline of the partition 401 is designed to fit and cover the end side walls of the two box girders 1 and the end face of the bottom formwork 301, forming a closed concrete pouring cavity end face. At the same time, a sealing gasket or grout-stopping strip is provided between the contact surfaces of the partition 401 and the box girders 1 and the bottom formwork 301. The sealing gasket can be made of rubber or foam material, and its elastic deformation fills the tiny gaps between the contact surfaces, effectively preventing cement grout from leaking from the joint, and ensuring the appearance quality and density of the concrete at the end of the wet joint.

[0030] Working principle: When constructing the wet joint of the small box girder, firstly, two adjacent box girders 1 are erected on the pier support. At this time, a wet joint gap is naturally formed between the flange plates of the two box girders 1. The operator then moves the load-bearing component 3 to the gap position and aligns the sliding blocks 302 protruding on both sides of the bottom formwork 301 with the opening of the groove 303 on the side wall of the box girder 1.

[0031] Next, the bottom formwork 301 is pushed to slide into the space between the two box girders 1 along the direction of the slide groove 303. With the interlocking cooperation between the sliding block 302 and the slide groove 303, the bottom formwork 301 is stably suspended at the bottom of the wet joint gap. There is no need to set up a ground support or use complicated hanging equipment. At this time, the bottom formwork 301, the sliding block 302 and the slide groove 303 work together to achieve the self-supporting installation of the bottom formwork, and allow the bottom formwork 301 to be finely adjusted in the horizontal direction to adapt to the construction error of the spacing of the box girders 1.

[0032] Subsequently, the steel bars 2 extending from the side walls of the box girder 1 on both sides are staggered or welded above the bearing component 3 to form a steel reinforcement skeleton. Before pouring concrete, the ends of the wet joints are sealed using the fixing component 4. The operator attaches the partition plate 401 to cover the end faces of the box girder 1 and the bottom formwork 301, so that the screw holes 404 on the partition plate 401 are aligned with the first connecting groove 402 on the box girder 1 and the second connecting groove 403 on the bottom formwork 301, respectively.

[0033] Finally, screws 405 are passed through the screw holes 404 on the partition plate 401 and screwed into the pre-embedded internal threads in the first connecting groove 402 and the second connecting groove 403 respectively and tightened. As the screws 405 are tightened, the partition plate 401 tightly pulls the left box girder 1, the right box girder 1 and the bottom formwork 301 in the middle together to form a rigid integral structure. This not only seals the end opening to prevent grout leakage, but also enhances the stability of the bottom formwork 301. Then, concrete is poured into the closed cavity. After the concrete solidifies, the bottom formwork 301 is bonded to the new concrete by the grooves 304 on its surface, completing the construction of the wet joint.

Claims

1. A wet joint structure with bottom formwork for the cast-in-place layer of a small box girder bridge deck, comprising: Two box girders (1) are arranged side by side at intervals, and a wet joint gap is formed between the side walls of the box girders (1); Its features are, The wet joint structure also includes a load-bearing component (3) installed at the bottom of the wet joint gap, and a fixing component (4) sealed at the end of the wet joint gap. The bearing component (3) includes a bottom mold (301) located in the wet joint gap, and sliding blocks (302) disposed on the side walls of both sides of the bottom mold (301). The box girder (1) has a groove (303) along its length on the side wall facing the wet joint gap. The sliding block (302) is slidably fitted inside the groove (303), so that the bottom mold (301) is mounted between the two box girders (1) through the snap-fit ​​between the sliding block (302) and the groove (303). The fixing component (4) includes a partition (401) that fits and covers the opening at the end of the wet joint gap, and screws (405) for fastening the connection. The end sidewall of the box girder (1) is provided with a first connecting groove (402), the end face of the bottom mold (301) is provided with a second connecting groove (403), and the surface of the partition plate (401) is provided with a through screw hole (404). When the partition plate (401) covers the end face of the box girder (1) and the bottom mold (301), the position of the screw hole (404) is connected to the position of the first connecting groove (402) and the second connecting groove (403) respectively; The screw (405) passes through the screw hole (404) and is screwed into the internal threaded connectors embedded in the first connecting groove (402) and the second connecting groove (403) respectively, so as to fix the two box beams (1) and the bottom mold (301) into a rigid whole.

2. The wet joint structure with bottom formwork for the cast-in-place layer of the small box girder bridge deck according to claim 1, characterized in that, The upper surface of the bottom mold (301) is provided with a plurality of grooves (304), which are arranged at intervals along the width or length direction of the bottom mold (301) to increase the contact area between the bottom mold (301) and the cast-in-place concrete; the bottom mold (301) is covered with reinforcing ribs (305), which extend along the length direction of the bottom mold (301) to enhance the structural strength of the bottom mold (301).

3. The wet joint structure with bottom formwork for the cast-in-place layer of the small box girder bridge deck according to claim 1, characterized in that, Several steel bars (2) extend laterally from the upper side wall of the box girder (1), and the steel bars (2) are suspended above the bearing component (3); the steel bars (2) extending from two adjacent box girders (1) are staggered or welded together in the space above the wet joint gap to form a skeleton structure for pouring concrete.

4. The wet joint structure with bottom formwork for the cast-in-place layer of the small box girder bridge deck according to claim 1, characterized in that, The cross-sectional shape of the groove (303) is a dovetail, T-shaped or trapezoidal structure, and the sliding block (302) has a protruding structure that matches the shape of the groove (303); the bottom mold (301) is embedded in the groove (303) by the sliding block (302) to restrict the vertical displacement of the bottom mold (301) relative to the box girder (1).

5. The wet joint structure with bottom formwork for the cast-in-place layer of the small box girder bridge deck according to claim 1, characterized in that, The first connecting groove (402) is located on the end side wall of the box girder (1) near the sliding groove (303), and the second connecting groove (403) is located on the end face of the bottom mold (301) near the sliding block (302); the length of the screw (405) is greater than the thickness of the partition plate (401), and the screw (405) is locked with the first connecting groove (402) and the second connecting groove (403) by means of thread engagement.

6. The wet joint structure with bottom formwork for the cast-in-place layer of the small box girder bridge deck according to claim 1, characterized in that, The outline of the partition (401) is adapted to cover the end sidewalls of the two box girders (1) and the end face of the bottom mold (301) to form a closed concrete pouring cavity end face; a sealing gasket or grout stop strip is provided between the contact surfaces of the partition (401) and the box girders (1) and the bottom mold (301).

7. The wet joint structure with bottom formwork for the cast-in-place layer of the small box girder bridge deck according to claim 1, characterized in that, The bottom mold (301) is a precast concrete component. The bottom mold (301) is retained as a permanent template in the wet joint structure after the pouring is completed, and is integrated with the newly poured concrete.

8. The wet joint structure with bottom formwork for the cast-in-place layer of the small box girder bridge deck according to claim 2, characterized in that, The groove (304) has an inverted trapezoidal or rectangular cross-section, and the depth of the groove (304) is less than half the thickness of the bottom mold (301). The reinforcing rib (305) is located below the groove (304).

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