Foundation sand box for quickly dismantling large-span bent cap rigid support and formwork system

Abstract

The utility model discloses a basic sand box for fast dismantling a large-span cover beam rigid support and a formwork system, which comprises a box body and a sand layer filled in the box body, the box body is a square box body structure with an opening at the top, the tops of a pair of oppositely arranged wall plates of the box body are concavely provided with open grooves which are used as sand leakage holes, and the open grooves are communicated with the sand leakage holes. Baffles are tightly attached to the outer sides of the pair of wall plates and used for blocking the sand leakage holes, the baffles are connected with the corresponding wall plates through bolts, the space between the pair of baffles and the inner cavity of the box body is filled with a sand layer, a cover plate covers the sand layer on the top opening of the box body, and any outer periphery of the cover plate does not protrude out of the inner wall of the box body. And the top surfaces of the pair of baffles are lower than the top surface of the cover plate. The large-span rigid support formwork system can be rapidly dismantled and put into secondary use, the construction efficiency is greatly improved, and the large-span rigid support formwork system has the advantages of being efficient, durable, economical and the like and is wide in application prospect.

Description

Technical Field

[0001] This utility model relates to the field of municipal elevated bridge technology. More specifically, this utility model relates to a foundation sandbox for the rapid dismantling of rigid supports and formwork systems for large-span cap beams. Background Technology

[0002] In road reconstruction and expansion projects, ensuring normal traffic flow is often a priority. Portal steel trusses are typically used as the primary support system for cap beam construction. Portal steel trusses are generally heavy, with the upper load concentrated on the lower legs. While this type of support system is easy to erect, it is difficult to dismantle, especially after the cap beam concrete is poured. The support structure undergoes elastic deformation under pressure, further compressing the gaps between the jacks and members, making dismantling extremely difficult. Therefore, an auxiliary tool is needed that can provide sufficient strength to support the upper load before pouring and facilitate rapid dismantling after pouring. Utility Model Content

[0003] One objective of this invention is to provide a foundation sandbox for the rapid dismantling of rigid supports and formwork systems for large-span cap beams. This allows for the rapid dismantling of large-span rigid support and formwork systems, enabling reuse and significantly improving construction efficiency. It offers advantages such as high efficiency, durability, and economy, and has broad application prospects.

[0004] To address the aforementioned technical problems, this utility model provides a foundation sandbox for the rapid dismantling of rigid supports and formwork systems for large-span cap beams. The sandbox includes a box body and a sand layer filling the box body. The box body is a square box structure with an open top. A pair of opposite wall panels in the box body have downward-facing recessed slots at their tops, serving as sand drainage holes. Baffles are tightly attached to the outer sides of each pair of wall panels to block the sand drainage holes. The baffles are bolted to the corresponding wall panels. The space between the pair of baffles and the inner cavity of the box body is filled with a sand layer. A cover plate is placed over the sand layer at the top opening of the box body, with no outer periphery protruding beyond the inner wall of the box body. The top surfaces of the pair of baffles are lower than the top surface of the cover plate.

[0005] Preferably, the baffle has a pair of vertical elongated circular holes facing each other, and the corresponding wall plate has a pair of threaded holes. The baffle and the wall plate are connected by bolts passing through the elongated circular holes and the threaded holes.

[0006] Preferably, the sand discharge hole is square and symmetrically arranged with respect to the axis of symmetry of the wall panel, and the width of the sand discharge hole is greater than the width of the foundation beam so as not to interfere with the descent of the foundation beam.

[0007] Preferably, the cover plate is square, and the central axis of the cover plate coincides with the central axis of the box body.

[0008] Preferably, the gap between the cover plate and the inner wall of the box is filled with sealant.

[0009] Preferably, a washer is provided between the head of the bolt and the baffle.

[0010] Preferably, a pair of vertical U-shaped steel bars are fixedly arranged on the cover plate, with their openings facing the wall panel, and the distance between the pair of U-shaped steel bars is greater than the width of the sand discharge hole.

[0011] This utility model has at least the following beneficial effects:

[0012] 1. High Efficiency. This system revolutionizes the traditional scaffolding dismantling sequence, achieving a "fundamental solution" by enabling simultaneous installation and dismantling of the same scaffolding and formwork system. This significantly reduces the waiting time for construction materials and improves material turnover efficiency. The effectiveness of the same scaffolding and formwork system is judged by the reuse of the foundation beams. Comparison shows that using the foundation steel sandbox of this application reduces the installation and dismantling efficiency of the scaffolding and formwork system by 6 days, resulting in an overall efficiency improvement of 31.6%.

[0013] 2. Durability. All components of the sandbox are made of steel, which ensures good durability. Even if damage occurs, it can be quickly repaired by welding.

[0014] 3. Economic Efficiency. The basic steel sandbox has high rigidity, is not easily deformed, and can be reused. By lining the sand discharge holes with plastic film, fine sand can be collected promptly during discharge and reused. The sandbox itself is simple and quick to install, and its use significantly shortens the overall construction cycle, greatly reduces the investment in manual labor and machinery, resulting in considerable economic benefits.

[0015] Other advantages, objectives and features of this invention will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the assembled and usable sandbox structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the sandbox blasting structure of this utility model;

[0018] Figure 3 This is a side view of the sandbox of this utility model.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. Box body, 2. Sand drain hole, 3. Baffle, 4. Bolt, 5. Cover plate, 6. Long strip hole, 7. Threaded hole, 8. U-shaped steel bar. Detailed Implementation

[0021] To better understand the purpose, structure, and function of this utility model, the following detailed description is provided in conjunction with the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0022] It should be noted that in the description of this utility model, the terms "horizontal", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0023] like Figures 1 to 3 As shown, this utility model provides a foundation sandbox for the rapid dismantling of rigid supports and formwork systems for large-span cap beams. It includes a box body 1 and a sand layer filled within the box body. The box body is a square box structure with an open top. A pair of opposite wall panels in the box body have downward-facing recessed slots at their tops, serving as sand drainage holes 2. Baffles 3 are tightly attached to the outer sides of each pair of wall panels to block the sand drainage holes. The baffles are connected to the corresponding wall panels by bolts 4. The space between the pair of baffles and the inner cavity of the box body is filled with the sand layer. A cover plate 5 is placed over the sand layer at the top opening of the box body. No outer periphery of the cover plate protrudes beyond the inner wall of the box body. The top surfaces of the pair of baffles are lower than the top surface of the cover plate. The cover plate is square, and its central axis coincides with the central axis of the box body. The gap between the cover plate and the inner wall of the box body is filled with sealant. The sand drainage holes are square and symmetrically arranged with respect to the axis of symmetry of the wall panels. The width of the sand drainage holes is greater than the width of the foundation beam to avoid interfering with the descent of the foundation beam.

[0024] The baffle has a pair of vertically elongated circular holes 6 facing each other, and the corresponding wall panel has a pair of threaded holes 7. The baffle and the wall panel are connected by bolts passing through the elongated circular holes and the threaded holes. A washer is placed between the head of the bolt and the baffle. The baffle is designed with a long slot, so that when the height is reduced in the early stage, the baffle follows the cover plate down, ensuring stability during the initial descent. After the height is reduced by 2-3cm, and the main beam and support deform and the stress is released, the baffle can be removed, which is safer and will not cause sudden descent or uneven displacement.

[0025] A pair of vertical U-shaped steel bars 8 are fixedly arranged on the cover plate, with their openings facing the wall panel. The spacing between the pair of U-shaped steel bars is greater than the width of the sand discharge hole, which is used for hoisting. The openings of the pair of U-shaped steel bars are in opposite directions.

[0026] In one specific application example of this application, the main information of the sandbox is as follows: The steel sandbox is welded from stainless steel plates, with 25mm thick steel plates for the wall panels and 30mm thick steel plates for the bottom and cover plates. The overall dimensions are: length * width * height = 600mm * 600mm * 150mm. The two symmetrical wall panels have slots as sand drainage holes, with dimensions of length * height = 300mm * 80mm. Sand drainage hole baffles are installed on the outer side of the wall panels corresponding to the sand drainage holes, with dimensions of length * height = 500mm * 100mm. The sand drainage hole baffles are fixed to the wall panels of the sandbox using D25 bolts and washers. The top cover plate of the sandbox is made of 30mm thick stainless steel plate, with dimensions of length * width = 540mm * 540mm. U-shaped steel bars are welded to the top plate for easy hoisting, and the position of the U-shaped steel bars is designed not to interfere with the installation of the foundation beams.

[0027] The internal filling sand is extra-fine sand with an average particle size of less than 0.25mm, which is cooked and cooled before use.

[0028] How the sandbox in this application works:

[0029] The interior of the box is filled with ultra-fine sand to form a sand layer. After being roasted at high temperature to remove moisture, this ensures the compactness of the filling. Before filling, ensure the bolts of the sand drain hole baffles are tightened. After the fine sand is filled to the same height as the box surface, cover it with a steel cover plate. Use a rubber mallet to tap the surface of the cover plate, which not only makes the sand more compact but also allows for fine-tuning of the steel cover plate to ensure it is centered in the sand box and has gaps between it and the inner walls of the box, ensuring that the cover plate will not be obstructed when lowering after sand discharge. After confirming the position of the cover plate is correct, fill the gaps between the cover plate and the sand box with sealant to prevent moisture from entering and to prevent fine sand from being lost due to wind. Then, the scaffolding can be erected. After the concrete pouring is completed and the strength reaches the requirements for removing the formwork, loosen the bolts and remove the sand drain hole baffles. The fine sand will slowly flow out under the pressure from above. A small hook rake can also be used to assist in the outward discharge of sand. At this time, it should be noted that all sand boxes should discharge sand simultaneously to ensure that the entire scaffolding system lowers evenly. The standard support system lowers the sandbox by 3-5cm, and the sandbox can be lowered by up to 7cm, providing sufficient space above for dismantling operations. A plastic film is placed over the sand drain holes, allowing for the timely collection and reuse of fine sand during drainage.

[0030] The effectiveness of the same set of support formwork system can be judged by the secondary use of the basic beams, and the following effectiveness comparison table 1 can be obtained.

[0031] Table 1 Comparison of Efficacy

[0032]

[0033] By comparison, it can be seen that after using the innovative basic steel sandbox of this application, the installation and dismantling efficiency of the support template system is reduced by 6 days compared with the original, and the overall efficiency is improved by 31.6%.

[0034] This application mainly covers the following two technical issues and corresponding solutions.

[0035] (1) The upper load of the support is large (the self-weight of the support + the self-weight of the main beam + the self-weight of the cap beam formwork + the load of the cap beam reinforced concrete + the construction load). It is necessary to select appropriate auxiliary tools so that the load can be effectively transferred and not easily deformed, and can be easily removed after construction.

[0036] This application utilizes welded steel plates to construct the foundation box. The box itself is sturdy and resistant to deformation, and its shear resistance and load-bearing capacity meet construction requirements. The box's interior is filled with fine sand through a cavity. Openable sand drain holes are pre-drilled on both sides of the steel plate. The box cover's dimensions are slightly smaller than the opening, and the top cover's height is determined based on the internal sand filling height. The foundation main beam is placed lengthwise above the sand boxes, ensuring even load distribution to each sand box. Support legs are fixed to the foundation main beam. After concrete pouring, the sand drain holes are opened to allow the fine sand to flow out, lowering the foundation main beam and reducing the overall height of the support structure. This reduces the load on the jacks, facilitating jack lowering and the removal of the load-bearing main beam and other structural components.

[0037] (2) In a conventional scaffolding system, the bottom formwork is placed directly on the upper longitudinal distribution beams, which are evenly distributed on the upper crossbeams. Below the upper crossbeams are the jacks, the main body of the scaffolding, and the foundation crossbeams. Theoretically, the scaffolding system should be dismantled from top to bottom. The bottom formwork has a large contact area with the cap beam, resulting in greater friction, making it difficult to dismantle. The large number of longitudinal distribution beams makes dismantling even more time-consuming. The upper crossbeams, however, consist of only two parallel beams, making them the easiest components to dismantle. The dismantling of the bottom formwork mainly relies on adjusting the jacks to reduce the forces between the scaffolding system members, thus facilitating the pulling out of the bottom formwork. However, the load borne by the jacks is very large, making it very difficult to adjust them without changing the load. Therefore, how to bypass the dismantling of the bottom formwork and longitudinal distribution beams and directly dismantle the upper crossbeams becomes the most pressing technical problem to be solved.

[0038] This application utilizes a specially designed sandbox. During the dismantling of the scaffolding system, after eliminating all temporary connections between the longitudinal distribution beams and the upper crossbeam, the longitudinal distribution beams are suspended from both ends using straps, allowing the weight of the longitudinal distribution beams and the bottom formwork to be borne by the straps. At this point, the sand drain holes inside the sandbox are opened to evenly discharge the fine sand from the sandbox cavity, causing the foundation crossbeam + scaffolding body + jacks + upper crossbeam to lower as a whole. A gap will remain between the upper crossbeam and the longitudinal distribution beams. At this point, the temporary connections between the main beam and the support are eliminated, separating the upper crossbeam from both the upper and lower structures. A truck crane is used to lift the upper crossbeam, and a hand-operated hoist is used to move it horizontally, thus achieving the removal of the upper crossbeam. After the upper crossbeam is removed, there is more operating space, allowing two truck cranes to work together to quickly remove the entire scaffolding body. The foundation crossbeam and steel sandbox can then be directly transported to the adjacent cap beam for construction. Finally, two cranes work together to dismantle the longitudinal distribution beams and the bottom formwork.

[0039] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model, and other modifications can be easily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and examples shown and described herein.

Claims

1. A foundation sandbox for rapid dismantling of rigid supports and formwork systems for large-span cap beams, characterized in that: The device includes a box body and a sand layer filling the box body. The box body is a square box structure with an open top. A pair of opposite wall panels in the box body have grooves recessed at the top, which serve as sand drainage holes. Baffles are tightly attached to the outer sides of the pair of wall panels to block the sand drainage holes. The baffles are connected to the corresponding wall panels by bolts. The space between the pair of baffles and the inner cavity of the box body is filled with a sand layer. A cover plate is placed on the sand layer at the top opening of the box body. Neither of the cover plate's outer perimeter protrudes from the inner wall of the box body. The top surface of the pair of baffles is lower than the top surface of the cover plate.

2. The foundation sandbox for rapid dismantling of rigid supports and formwork systems for large-span cap beams as described in claim 1, characterized in that, The baffle has a pair of vertical elongated circular holes facing each other, and the corresponding wall plate has a pair of threaded holes. The baffle and the wall plate are connected by bolts passing through the elongated circular holes and the threaded holes.

3. The foundation sandbox for rapid dismantling of rigid supports and formwork systems for large-span cap beams as described in claim 1, characterized in that... The sand discharge holes are square and symmetrically arranged with respect to the axis of symmetry of the wall panel. The width of the sand discharge holes is greater than the width of the foundation beam so as not to interfere with the descent of the foundation beam.

4. The foundation sandbox for rapid dismantling of rigid supports and formwork systems for large-span cap beams as described in claim 1, characterized in that... The cover plate is square, and the central axis of the cover plate coincides with the central axis of the box body.

5. The foundation sandbox for rapid dismantling of rigid supports and formwork systems for large-span cap beams as described in claim 1, characterized in that... The gap between the cover plate and the inner wall of the box is filled with sealant.

6. The foundation sandbox for rapid dismantling of rigid supports and formwork systems for large-span cap beams as described in claim 2, characterized in that... A washer is provided between the head of the bolt and the baffle.

7. The foundation sandbox for rapid dismantling of rigid supports and formwork systems for large-span cap beams as described in claim 1, characterized in that... A pair of vertical U-shaped steel bars are fixedly arranged on the cover plate, with their openings facing the wall panel, and the distance between the pair of U-shaped steel bars is greater than the width of the sand discharge hole.

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